The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.
A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.
Serum glycoproteins participating in the host defense mechanism of COMPLEMENT ACTIVATION that creates the COMPLEMENT MEMBRANE ATTACK COMPLEX. Included are glycoproteins in the various pathways of complement activation (CLASSICAL COMPLEMENT PATHWAY; ALTERNATIVE COMPLEMENT PATHWAY; and LECTIN COMPLEMENT PATHWAY).
A glycoprotein that is important in the activation of CLASSICAL COMPLEMENT PATHWAY. C4 is cleaved by the activated COMPLEMENT C1S into COMPLEMENT C4A and COMPLEMENT C4B.
C5 plays a central role in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C5 is cleaved by C5 CONVERTASE into COMPLEMENT C5A and COMPLEMENT C5B. The smaller fragment C5a is an ANAPHYLATOXIN and mediator of inflammatory process. The major fragment C5b binds to the membrane initiating the spontaneous assembly of the late complement components, C5-C9, into the MEMBRANE ATTACK COMPLEX.
Molecules on the surface of some B-lymphocytes and macrophages, that recognize and combine with the C3b, C3d, C1q, and C4b components of complement.
The larger fragment generated from the cleavage of COMPLEMENT C3 by C3 CONVERTASE. It is a constituent of the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb), and COMPLEMENT C5 CONVERTASES in both the classical (C4b2a3b) and the alternative (C3bBb3b) pathway. C3b participates in IMMUNE ADHERENCE REACTION and enhances PHAGOCYTOSIS. It can be inactivated (iC3b) or cleaved by various proteases to yield fragments such as COMPLEMENT C3C; COMPLEMENT C3D; C3e; C3f; and C3g.
A subcomponent of complement C1, composed of six copies of three polypeptide chains (A, B, and C), each encoded by a separate gene (C1QA; C1QB; C1QC). This complex is arranged in nine subunits (six disulfide-linked dimers of A and B, and three disulfide-linked homodimers of C). C1q has binding sites for antibodies (the heavy chain of IMMUNOGLOBULIN G or IMMUNOGLOBULIN M). The interaction of C1q and immunoglobulin activates the two proenzymes COMPLEMENT C1R and COMPLEMENT C1S, thus initiating the cascade of COMPLEMENT ACTIVATION via the CLASSICAL COMPLEMENT PATHWAY.
Complement activation initiated by the interaction of microbial ANTIGENS with COMPLEMENT C3B. When COMPLEMENT FACTOR B binds to the membrane-bound C3b, COMPLEMENT FACTOR D cleaves it to form alternative C3 CONVERTASE (C3BBB) which, stabilized by COMPLEMENT FACTOR P, is able to cleave multiple COMPLEMENT C3 to form alternative C5 CONVERTASE (C3BBB3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.
A 63-kDa serum glycoprotein encoded by gene C9. Monomeric C9 (mC9) binds the C5b-8 complex to form C5b-9 which catalyzes the polymerization of C9 forming C5b-p9 (MEMBRANE ATTACK COMPLEX) and transmembrane channels leading to lysis of the target cell. Patients with C9 deficiency suffer from recurrent bacterial infections.
Complement activation initiated by the binding of COMPLEMENT C1 to ANTIGEN-ANTIBODY COMPLEXES at the COMPLEMENT C1Q subunit. This leads to the sequential activation of COMPLEMENT C1R and COMPLEMENT C1S subunits. Activated C1s cleaves COMPLEMENT C4 and COMPLEMENT C2 forming the membrane-bound classical C3 CONVERTASE (C4B2A) and the subsequent C5 CONVERTASE (C4B2A3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.
A product of COMPLEMENT ACTIVATION cascade, regardless of the pathways, that forms transmembrane channels causing disruption of the target CELL MEMBRANE and cell lysis. It is formed by the sequential assembly of terminal complement components (COMPLEMENT C5B; COMPLEMENT C6; COMPLEMENT C7; COMPLEMENT C8; and COMPLEMENT C9) into the target membrane. The resultant C5b-8-poly-C9 is the "membrane attack complex" or MAC.
Serum proteins that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host. The complement system is tightly regulated by inactivators that accelerate the decay of intermediates and certain cell surface receptors.
A component of the CLASSICAL COMPLEMENT PATHWAY. C2 is cleaved by activated COMPLEMENT C1S into COMPLEMENT C2B and COMPLEMENT C2A. C2a, the COOH-terminal fragment containing a SERINE PROTEASE, combines with COMPLEMENT C4B to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).
A glycine-rich, heat-labile serum glycoprotein that contains a component of the C3 CONVERTASE ALTERNATE PATHWAY (C3bBb). Bb, a serine protease, is generated when factor B is cleaved by COMPLEMENT FACTOR D into Ba and Bb.
An important soluble regulator of the alternative pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It is a 139-kDa glycoprotein expressed by the liver and secreted into the blood. It binds to COMPLEMENT C3B and makes iC3b (inactivated complement 3b) susceptible to cleavage by COMPLEMENT FACTOR I. Complement factor H also inhibits the association of C3b with COMPLEMENT FACTOR B to form the C3bB proenzyme, and promotes the dissociation of Bb from the C3bBb complex (COMPLEMENT C3 CONVERTASE, ALTERNATIVE PATHWAY).
Compounds that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host.
The smaller fragment generated from the cleavage of complement C3 by C3 CONVERTASE. C3a, a 77-amino acid peptide, is a mediator of local inflammatory process. It induces smooth MUSCLE CONTRACTION, and HISTAMINE RELEASE from MAST CELLS and LEUKOCYTES. C3a is considered an anaphylatoxin along with COMPLEMENT C4A; COMPLEMENT C5A; and COMPLEMENT C5A, DES-ARGININE.
The minor fragment formed when C5 convertase cleaves C5 into C5a and COMPLEMENT C5B. C5a is a 74-amino-acid glycopeptide with a carboxy-terminal ARGININE that is crucial for its spasmogenic activity. Of all the complement-derived anaphylatoxins, C5a is the most potent in mediating immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE), smooth MUSCLE CONTRACTION; HISTAMINE RELEASE; and migration of LEUKOCYTES to site of INFLAMMATION.
A 105-kDa serum glycoprotein with significant homology to the other late complement components, C7-C9. It is a polypeptide chain cross-linked by 32 disulfide bonds. C6 is the next complement component to bind to the membrane-bound COMPLEMENT C5B in the assembly of MEMBRANE ATTACK COMPLEX. It is encoded by gene C6.
Molecular sites on or in some B-lymphocytes and macrophages that recognize and combine with COMPLEMENT C3B. The primary structure of these receptors reveal that they contain transmembrane and cytoplasmic domains, with their extracellular portion composed entirely of thirty short consensus repeats each having 60 to 70 amino acids.
The first complement component to act in the activation of CLASSICAL COMPLEMENT PATHWAY. It is a calcium-dependent trimolecular complex made up of three subcomponents: COMPLEMENT C1Q; COMPLEMENT C1R; and COMPLEMENT C1S at 1:2:2 ratios. When the intact C1 binds to at least two antibodies (involving C1q), C1r and C1s are sequentially activated, leading to subsequent steps in the cascade of COMPLEMENT ACTIVATION.
The large fragment formed when COMPLEMENT C4 is cleaved by COMPLEMENT C1S. The membrane-bound C4b binds COMPLEMENT C2A, a SERINE PROTEASE, to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).
Enzymes that activate one or more COMPLEMENT PROTEINS in the complement system leading to the formation of the COMPLEMENT MEMBRANE ATTACK COMPLEX, an important response in host defense. They are enzymes in the various COMPLEMENT ACTIVATION pathways.
A 302-amino-acid fragment in the alpha chain (672-1663) of C3b. It is generated when C3b is inactivated (iC3b) and its alpha chain is cleaved by COMPLEMENT FACTOR I into C3c, and C3dg (955-1303) in the presence COMPLEMENT FACTOR H. Serum proteases further degrade C3dg into C3d (1002-1303) and C3g (955-1001).
Serine proteases that cleave COMPLEMENT C3 into COMPLEMENT C3A and COMPLEMENT C3B, or cleave COMPLEMENT C5 into COMPLEMENT C5A and COMPLEMENT C5B. These include the different forms of C3/C5 convertases in the classical and the alternative pathways of COMPLEMENT ACTIVATION. Both cleavages take place at the C-terminal of an ARGININE residue.
Serologic tests based on inactivation of complement by the antigen-antibody complex (stage 1). Binding of free complement can be visualized by addition of a second antigen-antibody system such as red cells and appropriate red cell antibody (hemolysin) requiring complement for its completion (stage 2). Failure of the red cells to lyse indicates that a specific antigen-antibody reaction has taken place in stage 1. If red cells lyse, free complement is present indicating no antigen-antibody reaction occurred in stage 1.
A 93-kDa serum glycoprotein encoded by C7 gene. It is a polypeptide chain with 28 disulfide bridges. In the formation of MEMBRANE ATTACK COMPLEX; C7 is the next component to bind the C5b-6 complex forming a trimolecular complex C5b-7 which is lipophilic, resembles an integral membrane protein, and serves as an anchor for the late complement components, C8 and C9.
A 150-kDa serum glycoprotein composed of three subunits with each encoded by a different gene (C8A; C8B; and C8G). This heterotrimer contains a disulfide-linked C8alpha-C8gamma heterodimer and a noncovalently associated C8beta chain. C8 is the next component to bind the C5-7 complex forming C5b-8 that binds COMPLEMENT C9 and acts as a catalyst in the polymerization of C9.
A 206-amino-acid fragment in the alpha chain (672-1663) of C3b. It is generated when C3b is inactivated (iC3b) and its alpha chain is cleaved by COMPLEMENT FACTOR I into C3c (749-954), and C3dg (955-1303) in the presence COMPLEMENT FACTOR H.
Molecular sites on or in B-lymphocytes, follicular dendritic cells, lymphoid cells, and epithelial cells that recognize and combine with COMPLEMENT C3D. Human complement receptor 2 (CR2) serves as a receptor for both C3dg and the gp350/220 glycoprotein of HERPESVIRUS 4, HUMAN, and binds the monoclonal antibody OKB7, which blocks binding of both ligands to the receptor.
A screening assay for circulating COMPLEMENT PROTEINS. Diluted SERUM samples are added to antibody-coated ERYTHROCYTES and the percentage of cell lysis is measured. The values are expressed by the so called CH50, in HEMOLYTIC COMPLEMENT units per milliliter, which is the dilution of serum required to lyse 50 percent of the erythrocytes in the assay.
Endogenous proteins that inhibit or inactivate COMPLEMENT C3B. They include COMPLEMENT FACTOR H and COMPLEMENT FACTOR I (C3b/C4b inactivator). They cleave or promote the cleavage of C3b into inactive fragments, and thus are important in the down-regulation of COMPLEMENT ACTIVATION and its cytolytic sequence.
The smaller fragment formed when complement C4 is cleaved by COMPLEMENT C1S. It is an anaphylatoxin that causes symptoms of immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE) but its activity is weaker than that of COMPLEMENT C3A or COMPLEMENT C5A.
A serum protein which is important in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY. This enzyme cleaves the COMPLEMENT C3B-bound COMPLEMENT FACTOR B to form C3bBb which is ALTERNATIVE PATHWAY C3 CONVERTASE.
A plasma serine proteinase that cleaves the alpha-chains of C3b and C4b in the presence of the cofactors COMPLEMENT FACTOR H and C4-binding protein, respectively. It is a 66-kDa glycoprotein that converts C3b to inactivated C3b (iC3b) followed by the release of two fragments, C3c (150-kDa) and C3dg (41-kDa). It was formerly called KAF, C3bINF, or enzyme 3b inactivator.
A serum protein that regulates the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. It binds as a cofactor to COMPLEMENT FACTOR I which then hydrolyzes the COMPLEMENT C4B in the CLASSICAL PATHWAY C3 CONVERTASE (C4bC2a).
A 77-kDa subcomponent of complement C1, encoded by gene C1S, is a SERINE PROTEASE existing as a proenzyme (homodimer) in the intact complement C1 complex. Upon the binding of COMPLEMENT C1Q to antibodies, the activated COMPLEMENT C1R cleaves C1s into two chains, A (heavy) and B (light, the serine protease), linked by disulfide bonds yielding the active C1s. The activated C1s, in turn, cleaves COMPLEMENT C2 and COMPLEMENT C4 to form C4b2a (CLASSICAL C3 CONVERTASE).
A 80-kDa subcomponent of complement C1, existing as a SERINE PROTEASE proenzyme in the intact complement C1 complex. When COMPLEMENT C1Q is bound to antibodies, the changed tertiary structure causes autolytic activation of complement C1r which is cleaved into two chains, A (heavy) and B (light, the serine protease), connected by disulfide bonds. The activated C1r serine protease, in turn, activates COMPLEMENT C1S proenzyme by cleaving the Arg426-Ile427 bond. No fragment is released when either C1r or C1s is cleaved.
GPI-linked membrane proteins broadly distributed among hematopoietic and non-hematopoietic cells. CD55 prevents the assembly of C3 CONVERTASE or accelerates the disassembly of preformed convertase, thus blocking the formation of the membrane attack complex.
Small glycoproteins found on both hematopoietic and non-hematopoietic cells. CD59 restricts the cytolytic activity of homologous complement by binding to C8 and C9 and blocking the assembly of the membrane attack complex. (From Barclay et al., The Leukocyte Antigen FactsBook, 1993, p234)
Serum proteins that inhibit, antagonize, or inactivate COMPLEMENT C1 or its subunits.
The larger fragment generated from the cleavage of C5 by C5 CONVERTASE that yields COMPLEMENT C5A and C5b (beta chain + alpha' chain, the residual alpha chain, bound by disulfide bond). C5b remains bound to the membrane and initiates the spontaneous assembly of the late complement components to form C5b-8-poly-C9, the MEMBRANE ATTACK COMPLEX.
Complement activation triggered by the interaction of microbial POLYSACCHARIDES with serum MANNOSE-BINDING LECTIN resulting in the activation of MANNOSE-BINDING PROTEIN-ASSOCIATED SERINE PROTEASES. As in the classical pathway, MASPs cleave COMPLEMENT C4 and COMPLEMENT C2 to form C3 CONVERTASE (C4B2A) and the subsequent C5 CONVERTASE (C4B2A3B) leading to cleavage of COMPLEMENT C5 and assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.
A 53-kDa protein that is a positive regulator of the alternate pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It stabilizes the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb) and protects it from rapid inactivation, thus facilitating the cascade of COMPLEMENT ACTIVATION and the formation of MEMBRANE ATTACK COMPLEX. Individuals with mutation in the PFC gene exhibit properdin deficiency and have a high susceptibility to infections.
Venoms from snakes of the genus Naja (family Elapidae). They contain many specific proteins that have cytotoxic, hemolytic, neurotoxic, and other properties. Like other elapid venoms, they are rich in enzymes. They include cobramines and cobralysins.
The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.
An endogenous 105-kDa plasma glycoprotein produced primarily by the LIVER and MONOCYTES. It inhibits a broad spectrum of proteases, including the COMPLEMENT C1R and the COMPLEMENT C1S proteases of the CLASSICAL COMPLEMENT PATHWAY, and the MANNOSE-BINDING PROTEIN-ASSOCIATED SERINE PROTEASES. C1-INH-deficient individuals suffer from HEREDITARY ANGIOEDEMA TYPES I AND II.
Serum peptides derived from certain cleaved COMPLEMENT PROTEINS during COMPLEMENT ACTIVATION. They induce smooth MUSCLE CONTRACTION; mast cell HISTAMINE RELEASE; PLATELET AGGREGATION; and act as mediators of the local inflammatory process. The order of anaphylatoxin activity from the strongest to the weakest is C5a, C3a, C4a, and C5a des-arginine.
A serine protease that is the complex of COMPLEMENT C3B and COMPLEMENT FACTOR BB. It cleaves multiple COMPLEMENT C3 into COMPLEMENT C3A (anaphylatoxin) and COMPLEMENT C3B in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY.
A ubiquitously expressed complement receptor that binds COMPLEMENT C3B and COMPLEMENT C4B and serves as a cofactor for their inactivation. CD46 also interacts with a wide variety of pathogens and mediates immune response.
A G-protein-coupled receptor that signals an increase in intracellular calcium in response to the potent ANAPHYLATOXIN peptide COMPLEMENT C5A.
A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.
The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.
Proteins that bind to particles and cells to increase susceptibility to PHAGOCYTOSIS, especially ANTIBODIES bound to EPITOPES that attach to FC RECEPTORS. COMPLEMENT C3B may also participate.
The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).
The natural bactericidal property of BLOOD due to normally occurring antibacterial substances such as beta lysin, leukin, etc. This activity needs to be distinguished from the bactericidal activity contained in a patient's serum as a result of antimicrobial therapy, which is measured by a SERUM BACTERICIDAL TEST.
A specific mannose-binding member of the collectin family of lectins. It binds to carbohydrate groups on invading pathogens and plays a key role in the MANNOSE-BINDING LECTIN COMPLEMENT PATHWAY.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
An adhesion-promoting leukocyte surface membrane heterodimer. The alpha subunit consists of the CD11b ANTIGEN and the beta subunit the CD18 ANTIGEN. The antigen, which is an integrin, functions both as a receptor for complement 3 and in cell-cell and cell-substrate adhesive interactions.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Serum serine proteases which participate in COMPLEMENT ACTIVATION. They are activated when complexed with the MANNOSE-BINDING LECTIN, therefore also known as Mannose-binding protein-Associated Serine Proteases (MASPs). They cleave COMPLEMENT C4 and COMPLEMENT C2 to form C4b2a, the CLASSICAL PATHWAY C3 CONVERTASE.
Zymosan is a polysaccharide derived from the cell walls of Saccharomyces cerevisiae, commonly used in research as an immunostimulant to induce inflammation and study phagocytosis, complement activation, and oxidative burst in neutrophils and macrophages.
A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally being called a macroglobulin.
A derivative of complement C5a, generated when the carboxy-terminal ARGININE is removed by CARBOXYPEPTIDASE B present in normal human serum. C5a des-Arg shows complete loss of spasmogenic activity though it retains some chemotactic ability (CHEMOATTRACTANTS).
Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Antibodies produced by a single clone of cells.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Immunoglobulin molecules having a specific amino acid sequence by virtue of which they interact only with the ANTIGEN (or a very similar shape) that induced their synthesis in cells of the lymphoid series (especially PLASMA CELLS).
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
A class of C-type lectins that target the carbohydrate structures found on invading pathogens. Binding of collectins to microorganisms results in their agglutination and enhanced clearance. Collectins form trimers that may assemble into larger oligomers. Each collectin polypeptide chain consists of four regions: a relatively short N-terminal region, a collagen-like region, an alpha-helical coiled-coil region, and carbohydrate-binding region.
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
Degenerative changes in the RETINA usually of older adults which results in a loss of vision in the center of the visual field (the MACULA LUTEA) because of damage to the retina. It occurs in dry and wet forms.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
Proteins found in any species of bacterium.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
A method for the detection of very small quantities of antibody in which the antigen-antibody-complement complex adheres to indicator cells, usually primate erythrocytes or nonprimate blood platelets. The reaction is dependent on the number of bound C3 molecules on the C3b receptor sites of the indicator cell.
An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
A technique that combines protein electrophoresis and double immunodiffusion. In this procedure proteins are first separated by gel electrophoresis (usually agarose), then made visible by immunodiffusion of specific antibodies. A distinct elliptical precipitin arc results for each protein detectable by the antisera.
Immunoglobulins produced in a response to BACTERIAL ANTIGENS.
Established cell cultures that have the potential to propagate indefinitely.
Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.
Inflammation of the renal glomeruli (KIDNEY GLOMERULUS) that can be classified by the type of glomerular injuries including antibody deposition, complement activation, cellular proliferation, and glomerulosclerosis. These structural and functional abnormalities usually lead to HEMATURIA; PROTEINURIA; HYPERTENSION; and RENAL INSUFFICIENCY.
A condition characterized by the recurrence of HEMOGLOBINURIA caused by intravascular HEMOLYSIS. In cases occurring upon cold exposure (paroxysmal cold hemoglobinuria), usually after infections, there is a circulating antibody which is also a cold hemolysin. In cases occurring during or after sleep (paroxysmal nocturnal hemoglobinuria), the clonal hematopoietic stem cells exhibit a global deficiency of cell membrane proteins.
Group of diseases mediated by the deposition of large soluble complexes of antigen and antibody with resultant damage to tissue. Besides SERUM SICKNESS and the ARTHUS REACTION, evidence supports a pathogenic role for immune complexes in many other IMMUNE SYSTEM DISEASES including GLOMERULONEPHRITIS, systemic lupus erythematosus (LUPUS ERYTHEMATOSUS, SYSTEMIC) and POLYARTERITIS NODOSA.
Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.
Proteins prepared by recombinant DNA technology.
Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
The N-terminal fragment of COMPLEMENT 2, released by the action of activated COMPLEMENT C1S.
Abnormal immunoglobulins, especially IGG or IGM, that precipitate spontaneously when SERUM is cooled below 37 degrees Celsius. It is characteristic of CRYOGLOBULINEMIA.
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.
Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.
The phenomenon of target cell destruction by immunologically active effector cells. It may be brought about directly by sensitized T-lymphocytes or by lymphoid or myeloid "killer" cells, or it may be mediated by cytotoxic antibody, cytotoxic factor released by lymphoid cells, or complement.
The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)
The processes triggered by interactions of ANTIBODIES with their ANTIGENS.
A specific immune response elicited by a specific dose of an immunologically active substance or cell in an organism, tissue, or cell.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Antibodies that react with self-antigens (AUTOANTIGENS) of the organism that produced them.
The rate dynamics in chemical or physical systems.
Local surface sites on antibodies which react with antigen determinant sites on antigens (EPITOPES.) They are formed from parts of the variable regions of FAB FRAGMENTS.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.
The clear portion of BLOOD that is left after BLOOD COAGULATION to remove BLOOD CELLS and clotting proteins.
The in vitro formation of clusters consisting of a cell (usually a lymphocyte) surrounded by antigenic cells or antigen-bearing particles (usually erythrocytes, which may or may not be coated with antibody or antibody and complement). The rosette-forming cell may be an antibody-forming cell, a memory cell, a T-cell, a cell bearing surface cytophilic antibodies, or a monocyte possessing Fc receptors. Rosette formation can be used to identify specific populations of these cells.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
Glycoproteins found on the membrane or surface of cells.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Chronic glomerulonephritis characterized histologically by proliferation of MESANGIAL CELLS, increase in the MESANGIAL EXTRACELLULAR MATRIX, and a thickening of the glomerular capillary walls. This may appear as a primary disorder or secondary to other diseases including infections and autoimmune disease SYSTEMIC LUPUS ERYTHEMATOSUS. Various subtypes are classified by their abnormal ultrastructures and immune deposits. Hypocomplementemia is a characteristic feature of all types of MPGN.
Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.
Elements of limited time intervals, contributing to particular results or situations.
The phenomenon of antibody-mediated target cell destruction by non-sensitized effector cells. The identity of the target cell varies, but it must possess surface IMMUNOGLOBULIN G whose Fc portion is intact. The effector cell is a "killer" cell possessing Fc receptors. It may be a lymphocyte lacking conventional B- or T-cell markers, or a monocyte, macrophage, or polynuclear leukocyte, depending on the identity of the target cell. The reaction is complement-independent.
Inbred BALB/c mice are a strain of laboratory mice that have been selectively bred to be genetically identical to each other, making them useful for scientific research and experiments due to their consistent genetic background and predictable responses to various stimuli or treatments.
Serum globulins that migrate to the gamma region (most positively charged) upon ELECTROPHORESIS. At one time, gamma-globulins came to be used as a synonym for immunoglobulins since most immunoglobulins are gamma globulins and conversely most gamma globulins are immunoglobulins. But since some immunoglobulins exhibit an alpha or beta electrophoretic mobility, that usage is in decline.
A serine protease that cleaves multiple COMPLEMENT 3 into COMPLEMENT 3A (anaphylatoxin) and COMPLEMENT 3B in the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. It is a complex of COMPLEMENT 4B and COMPLEMENT 2A (C4b2a).
Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
A biosensing technique in which biomolecules capable of binding to specific analytes or ligands are first immobilized on one side of a metallic film. Light is then focused on the opposite side of the film to excite the surface plasmons, that is, the oscillations of free electrons propagating along the film's surface. The refractive index of light reflecting off this surface is measured. When the immobilized biomolecules are bound by their ligands, an alteration in surface plasmons on the opposite side of the film is created which is directly proportional to the change in bound, or adsorbed, mass. Binding is measured by changes in the refractive index. The technique is used to study biomolecular interactions, such as antigen-antibody binding.
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
Methods used by pathogenic organisms to evade a host's immune system.
Crystallizable fragments composed of the carboxy-terminal halves of both IMMUNOGLOBULIN HEAVY CHAINS linked to each other by disulfide bonds. Fc fragments contain the carboxy-terminal parts of the heavy chain constant regions that are responsible for the effector functions of an immunoglobulin (COMPLEMENT fixation, binding to the cell membrane via FC RECEPTORS, and placental transport). This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Transport proteins that carry specific substances in the blood or across cell membranes.
A dermal inflammatory reaction produced under conditions of antibody excess, when a second injection of antigen produces intravascular antigen-antibody complexes which bind complement, causing cell clumping, endothelial damage, and vascular necrosis.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
The property of antibodies which enables them to react with some ANTIGENIC DETERMINANTS and not with others. Specificity is dependent on chemical composition, physical forces, and molecular structure at the binding site.
The sum of the weight of all the atoms in a molecule.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
The functional hereditary units of BACTERIA.
Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.
Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.
Inflammation of any part of the KIDNEY.
A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.
A chelating agent that sequesters a variety of polyvalent cations such as CALCIUM. It is used in pharmaceutical manufacturing and as a food additive.
Specific molecular sites on the surface of various cells, including B-lymphocytes and macrophages, that combine with IMMUNOGLOBULIN Gs. Three subclasses exist: Fc gamma RI (the CD64 antigen, a low affinity receptor), Fc gamma RII (the CD32 antigen, a high affinity receptor), and Fc gamma RIII (the CD16 antigen, a low affinity receptor).
A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.
Polysaccharides found in bacteria and in capsules thereof.
Swelling involving the deep DERMIS, subcutaneous, or submucosal tissues, representing localized EDEMA. Angioedema often occurs in the face, lips, tongue, and larynx.
Proteins isolated from the outer membrane of Gram-negative bacteria.
Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)
An encapsulated lymphatic organ through which venous blood filters.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Molecules found on the surface of some, but not all, B-lymphocytes, T-lymphocytes, and macrophages, which recognize and combine with the Fc (crystallizable) portion of immunoglobulin molecules.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
White blood cells. These include granular leukocytes (BASOPHILS; EOSINOPHILS; and NEUTROPHILS) as well as non-granular leukocytes (LYMPHOCYTES and MONOCYTES).
Immunoglobulins produced in response to VIRAL ANTIGENS.
Substances elaborated by bacteria that have antigenic activity.
The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.
Substances that are recognized by the immune system and induce an immune reaction.
Limbless REPTILES of the suborder Serpentes.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
A major adhesion-associated heterodimer molecule expressed by MONOCYTES; GRANULOCYTES; NK CELLS; and some LYMPHOCYTES. The alpha subunit is the CD11C ANTIGEN, a surface antigen expressed on some myeloid cells. The beta subunit is the CD18 ANTIGEN.
Polysaccharides consisting of mannose units.
A highly conserved heterodimeric glycoprotein that is differentially expressed during many severe physiological disturbance states such as CANCER; APOPTOSIS; and various NEUROLOGICAL DISORDERS. Clusterin is ubiquitously expressed and appears to function as a secreted MOLECULAR CHAPERONE.
All blood proteins except albumin ( = SERUM ALBUMIN, which is not a globulin) and FIBRINOGEN (which is not in the serum). The serum globulins are subdivided into ALPHA-GLOBULINS; BETA-GLOBULINS; and GAMMA-GLOBULINS on the basis of their electrophoretic mobilities. (From Dorland, 28th ed)
A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.
Sites on an antigen that interact with specific antibodies.
The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
A group of antigens that includes both the major and minor histocompatibility antigens. The former are genetically determined by the major histocompatibility complex. They determine tissue type for transplantation and cause allograft rejections. The latter are systems of allelic alloantigens that can cause weak transplant rejection.
Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.
Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
A species of gram-negative, aerobic BACTERIA. It is a commensal and pathogen only of humans, and can be carried asymptomatically in the NASOPHARYNX. When found in cerebrospinal fluid it is the causative agent of cerebrospinal meningitis (MENINGITIS, MENINGOCOCCAL). It is also found in venereal discharges and blood. There are at least 13 serogroups based on antigenic differences in the capsular polysaccharides; the ones causing most meningitis infections being A, B, C, Y, and W-135. Each serogroup can be further classified by serotype, serosubtype, and immunotype.
Transfer of immunity from immunized to non-immune host by administration of serum antibodies, or transplantation of lymphocytes (ADOPTIVE TRANSFER).
Infections with bacteria of the species NEISSERIA MENINGITIDIS.
Adverse functional, metabolic, or structural changes in ischemic tissues resulting from the restoration of blood flow to the tissue (REPERFUSION), including swelling; HEMORRHAGE; NECROSIS; and damage from FREE RADICALS. The most common instance is MYOCARDIAL REPERFUSION INJURY.
Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (From Stedman, 26th ed)
Stable chromium atoms that have the same atomic number as the element chromium, but differ in atomic weight. Cr-50, 53, and 54 are stable chromium isotopes.
The relationships of groups of organisms as reflected by their genetic makeup.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.
The movement of leukocytes in response to a chemical concentration gradient or to products formed in an immunologic reaction.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
Solutions or mixtures of toxic and nontoxic substances elaborated by snake (Ophidia) salivary glands for the purpose of killing prey or disabling predators and delivered by grooved or hollow fangs. They usually contain enzymes, toxins, and other factors.
Antibodies found in adult RHEUMATOID ARTHRITIS patients that are directed against GAMMA-CHAIN IMMUNOGLOBULINS.
Antibodies from an individual that react with ISOANTIGENS of another individual of the same species.
Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.

Complement activity and pharmacological inhibition in cardiovascular disease. (1/54)

While complement is the most important component of humoral autoimmunity, and inflammation plays a key role in atherosclerosis, relatively few studies have looked at complement implications in atherosclerosis and its complications. C-reactive protein is a marker of inflammation and is also involved in atherosclerosis; it activates complement and colocalizes with activated complement proteins within the infarcting myocardium and the active atherosclerotic plaques. As new agents capable of modulating complement activity are being developed, new targets for the management of atherosclerosis are emerging that are related to autoimmunity and inflammation. The present paper reviews the putative roles of the various complement activation pathways in the development of atherosclerosis, in ST segment elevation and non-ST segment elevation acute coronary syndromes, and in coronary artery bypass graft surgery. It also provides a perspective on new therapeutic interventions being developed to modulate complement activity. These interventions include the C1 esterase inhibitor, which may be consumed in some inflammatory states resulting in the loss of one of the mechanisms inhibiting activation of the classical and lectin pathways; TP10, a recombinant protein of the soluble complement receptor type 1 (sCR1) which inhibits the C3 and C5 convertases of the common pathway by binding C3b and C4b; a truncated version of the soluble complement receptor type 1 CRI lacking the C4b binding site which selectively inhibits the alternative pathway; and pexelizumab, a monoclonal antibody selectively blocking C5 to prevent the activation of the terminal pathway that is involved in excessive inflammation and autoimmune responses.  (+info)

Therapeutic strategy with a membrane-localizing complement regulator to increase the number of usable donor organs after prolonged cold storage. (2/54)

A shortage of donor organs and increasing dependence on marginal grafts with prolonged ischemic times have meant that new methods are needed to prevent postischemic damage. Herein is reported a new strategy aimed to protect donor kidney from complement-mediated postischemic damage and therefore increase the number of successful transplants. Rat donor kidneys were perfused with a membrane-localizing complement regulator derived from human complement receptor type 1 (APT070) and then subjected to prolonged periods of cold storage (at 4 degrees C). A relationship was found between the duration of cold ischemia and the extent of complement-mediated tubule damage and loss of graft function. After 16 h of cold storage, APT070-treated kidneys that were transplanted into syngeneic recipients showed a significant increase in the number of surviving grafts, compared with control-treated grafts (63.6 versus 26.3%). Surviving grafts also displayed less acute tubular injury and better preservation of renal function. These results not only enhance the understanding of the mechanism by which prolonged cold ischemia reduces immediate graft survival but also provide essential information about the effectiveness of membrane-localizing complement regulator with prolonged cold storage. This could lead to more effective strategies for improving the use of severely ischemic donor organs.  (+info)

Relapsing fever spirochetes Borrelia recurrentis and B. duttonii acquire complement regulators C4b-binding protein and factor H. (3/54)

Relapsing fever is a rapidly progressive and severe septic disease caused by certain Borrelia spirochetes. The disease is divided into two forms, i.e., epidemic relapsing fever, caused by Borrelia recurrentis and transmitted by lice, and the endemic form, caused by several Borrelia species, such as B. duttonii, and transmitted by soft-bodied ticks. The spirochetes enter the bloodstream by the vector bite and live persistently in plasma even after the development of specific antibodies. This leads to fever relapses and high mortality and clearly indicates that the Borrelia organisms utilize effective immune evasion strategies. In this study, we show that the epidemic relapsing fever pathogen B. recurrentis and an endemic relapsing fever pathogen, B. duttonii, are serum resistant, i.e., resistant to complement in vitro. They acquire the host alternative complement pathway regulator factor H on their surfaces in a similar way to that of the less serum-resistant Lyme disease pathogen, B. burgdorferi sensu stricto. More importantly, the relapsing fever spirochetes specifically bind host C4b-binding protein, a major regulator of the antibody-mediated classical complement pathway. Both complement regulators retained their functional activities when bound to the surfaces of the spirochetes. In conclusion, this is the first report of complement evasion by Borrelia recurrentis and B. duttonii and the first report showing capture of C4b-binding protein by spirochetes.  (+info)

A novel inhibitor of the alternative pathway of complement reverses inflammation and bone destruction in experimental arthritis. (4/54)

Complement is an important component of the innate and adaptive immune response, yet complement split products generated through activation of each of the three complement pathways (classical, alternative, and lectin) can cause inflammation and tissue destruction. Previous studies have shown that complement activation through the alternative, but not classical, pathway is required to initiate antibody-induced arthritis in mice, but it is unclear if the alternative pathway (AP) plays a role in established disease. Previously, we have shown that human complement receptor of the immunoglobulin superfamily (CRIg) is a selective inhibitor of the AP of complement. Here, we present the crystal structure of murine CRIg and, using mutants, provide evidence that the structural requirements for inhibition of the AP are conserved in human and mouse. A soluble form of CRIg reversed inflammation and bone loss in two experimental models of arthritis by inhibiting the AP of complement in the joint. Our data indicate that the AP of complement is not only required for disease induction, but also disease progression. The extracellular domain of CRIg thus provides a novel tool to study the effects of inhibiting the AP of complement in established disease and constitutes a promising therapeutic with selectivity for a single complement pathway.  (+info)

Characterization of Ehp, a secreted complement inhibitory protein from Staphylococcus aureus. (5/54)

We report here the discovery and characterization of Ehp, a new secreted Staphylococcus aureus protein that potently inhibits the alternative complement activation pathway. Ehp was identified through a genomic scan as an uncharacterized secreted protein from S. aureus, and immunoblotting of conditioned S. aureus culture medium revealed that the Ehp protein was secreted at the highest levels during log-phase bacterial growth. The mature Ehp polypeptide is composed of 80 residues and is 44% identical to the complement inhibitory domain of S. aureus Efb (extracellular fibrinogen-binding protein). We observed preferential binding by Ehp to native and hydrolyzed C3 relative to fully active C3b and found that Ehp formed a subnanomolar affinity complex with these various forms of C3 by binding to its thioester-containing C3d domain. Site-directed mutagenesis demonstrated that Arg(75) and Asn(82) are important in forming the Ehp.C3d complex, but loss of these side chains did not completely disrupt Ehp/C3d binding. This suggested the presence of a second C3d-binding site in Ehp, which was mapped to the proximity of Ehp Asn(63). Further molecular level details of the Ehp/C3d interaction were revealed by solving the 2.7-A crystal structure of an Ehp.C3d complex in which the low affinity site had been mutationally inactivated. Ehp potently inhibited C3b deposition onto sensitized surfaces by the alternative complement activation pathway. This inhibition was directly related to Ehp/C3d binding and was more potent than that seen for Efb-C. An altered conformation in Ehp-bound C3 was detected by monoclonal antibody C3-9, which is specific for a neoantigen exposed in activated forms of C3. Our results suggest that increased inhibitory potency of Ehp relative to Efb-C is derived from the second C3-binding site in this new protein.  (+info)

Effect of the complement inhibitor eculizumab on thromboembolism in patients with paroxysmal nocturnal hemoglobinuria. (6/54)

Hemolysis and hemoglobinemia contribute to serious clinical sequelae in hemolytic disorders. In paroxysmal nocturnal hemoglobinuria (PNH) patients, hemolysis can contribute to thromboembolism (TE), the most feared complication in PNH, and the leading cause of disease-related deaths. We evaluated whether long-term treatment with the complement inhibitor eculizumab reduces the rate of TE in patients with PNH. Clinical trial participants included all patients in the 3 eculizumab PNH clinical studies, which recruited patients between 2002 and 2005 (n = 195); patients from these studies continued treatment in the current multinational open-label extension study. Thromboembolism rate with eculizumab treatment was compared with the pretreatment rate in the same patients. The TE event rate with eculizumab treatment was 1.07 events/100 patient-years compared with 7.37 events/100 patient-years (P < .001) prior to eculizumab treatment (relative reduction, 85%; absolute reduction, 6.3 TE events/100 patient-years). With equalization of the duration of exposure before and during treatment for each patient, TE events were reduced from 39 events before eculizumab to 3 events during eculizumab (P < .001). The TE event rate in antithrombotic-treated patients (n = 103) was reduced from 10.61 to 0.62 events/100 patient-years with eculizumab treatment (P < .001). These results show that eculizumab treatment reduces the risk of clinical thromboembolism in patients with PNH. This study is registered at http://clinicaltrials.gov (study ID no. NCT00122317).  (+info)

Management of hereditary angioedema in pediatric patients. (7/54)

Hereditary angioneurotic edema is a rare disorder caused by the congenital deficiency of C1 inhibitor. Recurring angioedematous paroxysms that most commonly involve the subcutis (eg, extremities, face, trunk, and genitals) or the submucosa (eg, intestines and larynx) are the hallmarks of hereditary angioneurotic edema. Edema formation is related to reduction or dysfunction of C1 inhibitor, and conventional therapy with antihistamines and corticosteroids is ineffective. Manifestations occur during the initial 2 decades of life, but even today there is a long delay between the onset of initial symptoms and the diagnosis of hereditary angioneurotic edema. Although a variety of reviews have been published during the last 3 decades on the general management of hereditary angioneurotic edema, little has been published regarding management of pediatric hereditary angioneurotic edema. Thus, we review our experience and published data to provide an approach to hereditary angioneurotic edema in childhood.  (+info)

Association of reactive oxygen and nitrogen intermediate and complement levels with apoptosis of peripheral blood mononuclear cells in lupus patients. (8/54)

OBJECTIVE: Both increased production of reactive oxygen and nitrogen intermediates (RONI) and reduced levels of complement may play a role in the increased apoptosis and reduced clearance of apoptotic cells in systemic lupus erythematosus (SLE). The objective of this study was to evaluate both processes in a parallel, prospective, longitudinal manner. METHODS: Sixty-seven SLE patients were evaluated during multiple visits, and 31 healthy control subjects were evaluated once or twice. Clinical and laboratory features of SLE disease activity were determined, and blood was collected for measurement of serum nitrate plus nitrite (NOx) levels and for isolation of peripheral blood mononuclear cells (PBMCs). PBMCs were cultured with a nitric oxide (NO) donor and SLE or control plasma, with or without heat inactivation, cobra venom factor (CVF), or lipopolysaccharide plus interferon-gamma treatment. Cells were analyzed for apoptotic index (AI), cellular subsets, and RONI production. RESULTS: The PBMC AI was associated with SLE and was inversely associated with complement levels over time. Changes in the AI with addition of a NO donor was longitudinally associated with serum NOx levels, and stimulation of SLE PBMCs led to parallel increases in RONI production and apoptosis. Addition of SLE plasma resulted in a greater PBMC AI, an effect that was increased with heat inactivation and was corrected with CVF treatment. CONCLUSION: These data suggest that the greater AI observed in SLE PBMCs relates to increased PBMC RONI production and reduced complement levels. The longitudinal nature of these parallel associations within individuals suggests that these processes are dynamic and additive.  (+info)

Complement activation is the process by which the complement system, a part of the immune system, is activated to help eliminate pathogens and damaged cells from the body. The complement system consists of a group of proteins that work together to recognize and destroy foreign substances.

Activation of the complement system can occur through three different pathways: the classical pathway, the lectin pathway, and the alternative pathway. Each pathway involves a series of proteolytic reactions that ultimately result in the formation of the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, leading to its lysis and removal.

The classical pathway is typically activated by the binding of antibodies to antigens on the surface of a pathogen or damaged cell. The lectin pathway is activated by the recognition of specific carbohydrate structures on the surface of microorganisms. The alternative pathway can be spontaneously activated and serves as an amplification loop for both the classical and lectin pathways.

Complement activation plays a crucial role in the immune response, but uncontrolled or excessive activation can also lead to tissue damage and inflammation. Dysregulation of complement activation has been implicated in various diseases, including autoimmune disorders, inflammatory conditions, and neurodegenerative diseases.

Complement C3 is a protein that plays a central role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Complement C3 can be activated through three different pathways: the classical pathway, the lectin pathway, and the alternative pathway. Once activated, it breaks down into two fragments, C3a and C3b.

C3a is an anaphylatoxin that helps to recruit immune cells to the site of infection or injury, while C3b plays a role in opsonization, which is the process of coating pathogens or damaged cells with proteins to make them more recognizable to the immune system. Additionally, C3b can also activate the membrane attack complex (MAC), which forms a pore in the membrane of target cells leading to their lysis or destruction.

In summary, Complement C3 is an important protein in the complement system that helps to identify and eliminate pathogens and damaged cells from the body through various mechanisms.

The complement system is a group of proteins found in the blood and on the surface of cells that when activated, work together to help eliminate pathogens such as bacteria, viruses, and fungi from the body. The proteins are normally inactive in the bloodstream. When they encounter an invading microorganism or foreign substance, a series of reactions take place leading to the activation of the complement system. Activation results in the production of effector molecules that can punch holes in the cell membranes of pathogens, recruit and activate immune cells, and help remove debris and dead cells from the body.

There are three main pathways that can lead to complement activation: the classical pathway, the lectin pathway, and the alternative pathway. Each pathway involves a series of proteins that work together in a cascade-like manner to amplify the response and generate effector molecules. The three main effector molecules produced by the complement system are C3b, C4b, and C5b. These molecules can bind to the surface of pathogens, marking them for destruction by other immune cells.

Complement proteins also play a role in the regulation of the immune response. They help to prevent excessive activation of the complement system, which could damage host tissues. Dysregulation of the complement system has been implicated in a number of diseases, including autoimmune disorders and inflammatory conditions.

In summary, Complement System Proteins are a group of proteins that play a crucial role in the immune response by helping to eliminate pathogens and regulate the immune response. They can be activated through three different pathways, leading to the production of effector molecules that mark pathogens for destruction. Dysregulation of the complement system has been linked to various diseases.

Complement C4 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Complement C4 is involved in the early stages of the complement activation cascade, where it helps to identify and tag foreign or abnormal cells for destruction by other components of the immune system.

Specifically, Complement C4 can be cleaved into two smaller proteins, C4a and C4b, during the complement activation process. C4b then binds to the surface of the target cell and helps to initiate the formation of the membrane attack complex (MAC), which creates a pore in the cell membrane and leads to lysis or destruction of the target cell.

Deficiencies or mutations in the Complement C4 gene can lead to various immune disorders, including certain forms of autoimmune diseases and susceptibility to certain infections.

Complement C5 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. The complement system is a complex series of biochemical reactions that help to identify and destroy foreign substances, such as bacteria and viruses.

Complement C5 is one of several proteins in the complement system that are activated in a cascading manner in response to an activating event, such as the binding of an antibody to a pathogen. Once activated, Complement C5 can be cleaved into two smaller proteins, C5a and C5b.

C5a is a powerful anaphylatoxin, which means it can cause the release of histamine from mast cells and basophils, leading to inflammation and increased vascular permeability. It also acts as a chemoattractant, drawing immune cells to the site of infection or injury.

C5b, on the other hand, plays a role in the formation of the membrane attack complex (MAC), which is a protein structure that can punch holes in the membranes of pathogens, leading to their lysis and destruction.

Overall, Complement C5 is an important component of the immune system's response to infection and injury, helping to eliminate pathogens and damaged cells from the body.

Complement receptors are proteins found on the surface of various cells in the human body, including immune cells and some non-immune cells. They play a crucial role in the complement system, which is a part of the innate immune response that helps to eliminate pathogens and damaged cells from the body. Complement receptors bind to complement proteins or fragments that are generated during the activation of the complement system. This binding triggers various intracellular signaling events that can lead to diverse cellular responses, such as phagocytosis, inflammation, and immune regulation.

There are several types of complement receptors, including:

1. CR1 (CD35): A receptor found on erythrocytes, B cells, neutrophils, monocytes, macrophages, and glomerular podocytes. It functions in the clearance of immune complexes and regulates complement activation.
2. CR2 (CD21): Expressed mainly on B cells and follicular dendritic cells. It facilitates antigen presentation, B-cell activation, and immune regulation.
3. CR3 (CD11b/CD18, Mac-1): Present on neutrophils, monocytes, macrophages, and some T cells. It mediates cell adhesion, phagocytosis, and intracellular signaling.
4. CR4 (CD11c/CD18, p150,95): Expressed on neutrophils, monocytes, macrophages, and dendritic cells. It is involved in cell adhesion, phagocytosis, and intracellular signaling.
5. C5aR (CD88): Found on various immune cells, including neutrophils, monocytes, macrophages, mast cells, eosinophils, and dendritic cells. It binds to the complement protein C5a and mediates chemotaxis, degranulation, and inflammation.
6. C5L2 (GPR77): Present on various cell types, including immune cells. Its function is not well understood but may involve regulating C5a-mediated responses or acting as a receptor for other ligands.

These receptors play crucial roles in the immune response and inflammation by mediating various functions such as chemotaxis, phagocytosis, cell adhesion, and intracellular signaling. Dysregulation of these receptors has been implicated in several diseases, including autoimmune disorders, infections, and cancer.

Complement C3b is a protein fragment that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. C3b is generated during the activation of the complement system, particularly via the classical, lectin, and alternative pathways.

Once formed, C3b can bind covalently to the surface of microbes or other target particles, marking them for destruction by other components of the immune system. Additionally, C3b can interact with other proteins in the complement system to generate the membrane attack complex (MAC), which forms pores in the membranes of targeted cells, leading to their lysis and removal.

In summary, Complement C3b is a vital protein fragment involved in the recognition, tagging, and elimination of pathogens and damaged cells during the immune response.

Complement C1q is a protein that is part of the complement system, which is a group of proteins in the blood that help to eliminate pathogens and damaged cells from the body. C1q is the first component of the classical complement pathway, which is activated by the binding of C1q to antibodies that are attached to the surface of a pathogen or damaged cell.

C1q is composed of six identical polypeptide chains, each containing a collagen-like region and a globular head region. The globular heads can bind to various structures, including the Fc regions of certain antibodies, immune complexes, and some types of cells. When C1q binds to an activating surface, it triggers a series of proteolytic reactions that lead to the activation of other complement components and the formation of the membrane attack complex (MAC), which can punch holes in the membranes of pathogens or damaged cells, leading to their destruction.

In addition to its role in the immune system, C1q has also been found to have roles in various physiological processes, including tissue remodeling, angiogenesis, and the clearance of apoptotic cells. Dysregulation of the complement system, including abnormalities in C1q function, has been implicated in a variety of diseases, including autoimmune disorders, inflammatory diseases, and neurodegenerative conditions.

The alternative complement pathway is one of the three initiating pathways of the complement system, which is a part of the innate immune system that helps to clear pathogens and damaged cells from the body. The other two pathways are the classical and lectin pathways.

The alternative pathway is continuously activated at a low level, even in the absence of infection or injury, through the spontaneous cleavage of complement component C3 into C3a and C3b by the protease factor D in the presence of magnesium ions. The generated C3b can then bind covalently to nearby surfaces, including pathogens and host cells.

On self-surfaces, regulatory proteins like decay-accelerating factor (DAF) or complement receptor 1 (CR1) help to prevent the formation of the alternative pathway convertase and thus further activation of the complement system. However, on foreign surfaces, the C3b can recruit more complement components, forming a complex called the alternative pathway convertase (C3bBb), which cleaves additional C3 molecules into C3a and C3b.

The generated C3b can then bind to the surface and participate in the formation of the membrane attack complex (MAC), leading to the lysis of the target cell. The alternative pathway plays a crucial role in the defense against gram-negative bacteria, fungi, and parasites, as well as in the clearance of immune complexes and apoptotic cells. Dysregulation of the alternative complement pathway has been implicated in several diseases, including autoimmune disorders and atypical hemolytic uremic syndrome (aHUS).

Complement C9 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, C9 is one of the components of the membrane attack complex (MAC), which is a protein structure that forms pores in the membranes of target cells, leading to their lysis or destruction.

When activated, C9 polymerizes and inserts itself into the cell membrane, forming a transmembrane pore that disrupts the membrane's integrity and causes the cell to lyse. This process is an essential part of the complement system's ability to destroy pathogens and clear damaged cells from the body.

Defects in the C9 gene can lead to a rare genetic disorder called complement component 9 deficiency, which is characterized by recurrent bacterial infections and immune complex-mediated diseases. Additionally, mutations in the C9 gene have been associated with an increased risk of age-related macular degeneration (AMD), a leading cause of blindness in older adults.

The "Classical Complement Pathway" is one of the three pathways that make up the complement system, which is a part of the immune system in humans and other animals. The complement system helps to enhance the ability of antibodies and phagocytic cells to clear pathogens from the body.

The Classical Complement Pathway is initiated by the binding of the first component of the complement system, C1, to an activator surface, such as an antigen-antibody complex. Activation of C1 results in the sequential activation of other components of the complement system, including C4 and C2, which form the C3 convertase (C4b2a). The C3 convertase cleaves the third component of the complement system, C3, into C3a and C3b. C3b then binds to the activator surface and forms a complex with other components of the complement system, leading to the formation of the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, causing its lysis.

The Classical Complement Pathway plays an important role in the immune response to pathogens and can also contribute to inflammation and tissue damage in certain diseases, such as autoimmune disorders and allergies.

The Complement Membrane Attack Complex (MAC), also known as the Terminal Complement Complex (TCC), is a protein structure that forms in the final stages of the complement system's immune response. The complement system is a part of the innate immune system that helps to eliminate pathogens and damaged cells from the body.

The MAC is composed of several proteins, including C5b, C6, C7, C8, and multiple subunits of C9, which assemble on the surface of target cells. The formation of the MAC creates a pore-like structure in the cell membrane, leading to disruption of the membrane's integrity and ultimately causing cell lysis or damage.

The MAC plays an important role in the immune response by helping to eliminate pathogens that have evaded other immune defenses. However, uncontrolled activation of the complement system and formation of the MAC can also contribute to tissue damage and inflammation in various diseases, such as autoimmune disorders, age-related macular degeneration, and ischemia-reperfusion injury.

Complement inactivator proteins are a group of regulatory proteins that help to control and limit the activation of the complement system, which is a part of the immune system. The complement system is a complex series of biochemical reactions that help to eliminate pathogens and damaged cells from the body. However, if not properly regulated, the complement system can also cause damage to healthy tissues and contribute to the development of various diseases.

Complement inactivator proteins work by inhibiting specific components of the complement system, preventing them from activating and causing an immune response. Some examples of complement inactivator proteins include:

1. C1 inhibitor (C1INH): This protein regulates the activation of the classical pathway of the complement system by inhibiting the C1 complex, which is a group of proteins that initiate this pathway.
2. Decay-accelerating factor (DAF or CD55): This protein regulates the activation of both the classical and alternative pathways of the complement system by accelerating the decay of the C3/C5 convertases, which are enzymes that activate the complement components C3 and C5.
3. Membrane cofactor protein (MCP or CD46): This protein regulates the activation of the alternative pathway of the complement system by serving as a cofactor for the cleavage and inactivation of C3b, a component of the C3 convertase.
4. Factor H: This protein also regulates the activation of the alternative pathway of the complement system by acting as a cofactor for the cleavage and inactivation of C3b, and by preventing the formation of the C3 convertase.

Deficiencies or dysfunction of complement inactivator proteins can lead to various diseases, including hereditary angioedema (C1INH deficiency), atypical hemolytic uremic syndrome (factor H deficiency or dysfunction), and age-related macular degeneration (complement component overactivation).

Complement C2 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, C2 is a component of the classical complement pathway, which is activated by the binding of antibodies to antigens on the surface of foreign particles or cells.

When the classical pathway is activated, C2 is cleaved into two fragments: C2a and C2b. C2a then binds to C4b to form the C3 convertase (C4b2a), which cleaves C3 into C3a and C3b. C3b can then go on to form the membrane attack complex, which creates a pore in the membrane of the target cell, leading to its lysis.

In summary, Complement C2 is a protein that helps to activate the complement system and destroy foreign particles or cells through the formation of the C3 convertase and the membrane attack complex.

Complement Factor B is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, Factor B is a component of the alternative pathway of the complement system, which provides a rapid and amplified response to microbial surfaces.

Factor B is cleaved by another protease called Factor D into two fragments, Ba and Bb. The formation of the C3 convertase (C3bBb) is essential for the activation of the alternative pathway. This complex can cleave and activate more C3 molecules, leading to a cascade of reactions that result in the formation of the membrane attack complex (MAC), which forms pores in the membranes of target cells, causing their lysis and elimination.

Deficiencies or mutations in Complement Factor B can lead to various complement-mediated diseases, such as atypical hemolytic uremic syndrome (aHUS) and age-related macular degeneration (AMD).

Complement Factor H is a protein involved in the regulation of the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, Complement Factor H helps to regulate the activation and deactivation of the complement component C3b, preventing excessive or unwanted activation of the complement system and protecting host tissues from damage.

Complement Factor H is a crucial protein in maintaining the balance between the protective effects of the complement system and the potential for harm to the body's own cells and tissues. Deficiencies or mutations in Complement Factor H have been associated with several diseases, including age-related macular degeneration (AMD), atypical hemolytic uremic syndrome (aHUS), and C3 glomerulopathy.

Complement inactivating agents are substances or drugs that inhibit the complement system, which is a part of the immune system responsible for the recognition and elimination of foreign substances and microorganisms. The complement system consists of a group of proteins that work together to help eliminate pathogens from the body.

Complement inactivating agents are used in medical settings to prevent or treat various conditions associated with excessive or unwanted activation of the complement system, such as inflammation, autoimmune diseases, and transplant rejection. These agents can inhibit different components of the complement pathway, including C1 esterase inhibitors, C3 convertase inhibitors, and C5a receptor antagonists.

Examples of complement inactivating agents include eculizumab, ravulizumab, and Alexion's Ultomiris, which are monoclonal antibodies that target C5, a protein involved in the final steps of the complement pathway. These drugs have been approved for the treatment of paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), and other complement-mediated diseases.

Other complement inactivating agents include C1 esterase inhibitors, such as Berinert and Ruconest, which are used to treat hereditary angioedema (HAE). These drugs work by inhibiting the activation of the classical pathway of the complement system, thereby preventing the release of inflammatory mediators that can cause swelling and pain.

Overall, complement inactivating agents play an important role in the treatment of various complement-mediated diseases, helping to reduce inflammation, prevent tissue damage, and improve patient outcomes.

Complement C3a is a protein fragment that is generated during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by marking them for destruction and attracting immune cells to the site of infection or injury.

C3a is produced when the third component of the complement system (C3) is cleaved into two smaller fragments, C3a and C3b, during the complement activation cascade. C3a is a potent anaphylatoxin, which means it can cause the release of histamine and other mediators from mast cells and basophils, leading to inflammation, increased vascular permeability, and smooth muscle contraction.

C3a also has chemotactic properties, meaning it can attract immune cells such as neutrophils and monocytes to the site of complement activation. Additionally, C3a can modulate the activity of various immune cells, including dendritic cells, T cells, and B cells, and play a role in the regulation of the adaptive immune response.

It's important to note that while C3a has important functions in the immune response, uncontrolled or excessive activation of the complement system can lead to tissue damage and inflammation, contributing to the pathogenesis of various diseases such as autoimmune disorders, inflammatory diseases, and allergies.

Complement C5a is a protein fragment that is generated during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by tagging them for destruction and attracting immune cells to the site of infection or injury.

C5a is formed when the fifth component of the complement system (C5) is cleaved into two smaller fragments, C5a and C5b, during the complement activation cascade. C5a is a potent pro-inflammatory mediator that can attract and activate various immune cells, such as neutrophils, monocytes, and eosinophils, to the site of infection or injury. It can also increase vascular permeability, promote the release of histamine, and induce the production of reactive oxygen species, all of which contribute to the inflammatory response.

However, excessive or uncontrolled activation of the complement system and generation of C5a can lead to tissue damage and inflammation, contributing to the pathogenesis of various diseases, such as sepsis, acute respiratory distress syndrome (ARDS), and autoimmune disorders. Therefore, targeting C5a or its receptors has been explored as a potential therapeutic strategy for these conditions.

Complement C6 is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, C6 is a component of the membrane attack complex (MAC), which is a group of proteins that work together to form a pore in the membrane of target cells, leading to their lysis or destruction.

The complement system is activated through several different pathways, including the classical pathway, the lectin pathway, and the alternative pathway. Once activated, these pathways converge at the level of C3, which is cleaved into C3a and C3b fragments. C3b can then bind to the surface of target cells and initiate the formation of the MAC.

C6 is one of several proteins that are required for the formation of the MAC. When C6 binds to C7, it undergoes a conformational change that allows it to interact with C8 and form a stable complex. This complex then recruits additional C9 molecules, which polymerize to form the pore in the target cell membrane.

Deficiencies in complement components, including C6, can lead to increased susceptibility to certain types of infections, as well as autoimmune disorders and other medical conditions.

Complement receptor 3b (CR3b or CD11b/CD18) is not a medical definition itself, but I can provide you with the relevant information regarding this term.

Complement receptor 3 (CR3) is a heterodimeric receptor consisting of two subunits, CD11b (also known as Mac-1 or CR3 alpha) and CD18 (also known as beta2 integrin). There are two forms of the CD11b/CD18 heterodimer: CR3a (CD11b/CD18) and CR3b (CD11b/CD18'). The difference between these two forms lies in the conformation of the CD11b subunit.

Complement receptor 3b (CR3b or CD11b/CD18') is a less common form of the CR3 receptor, which is primarily expressed on myeloid cells such as monocytes, macrophages, and neutrophils. CR3b has a higher affinity for complement component C3b and its fragments iC3b and C3dg compared to CR3a.

CR3b plays a role in various immune functions, including:

1. Phagocytosis: Binding of C3b or its fragments to CR3b facilitates the recognition and uptake of opsonized pathogens by phagocytes.
2. Adhesion: The integrin component of CR3b mediates cell-cell and cell-matrix interactions, contributing to leukocyte migration and recruitment to sites of inflammation or infection.
3. Intracellular signaling: Activation of CR3b can lead to intracellular signaling events that modulate immune responses, such as the release of pro-inflammatory cytokines and reactive oxygen species.

In summary, Complement receptor 3b (CR3b or CD11b/CD18') is a less common form of CR3 primarily expressed on myeloid cells that binds complement component C3b and its fragments with high affinity, mediating phagocytosis, adhesion, and intracellular signaling.

Complement C1 is a protein complex that plays a crucial role in the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. The complement system consists of a group of proteins that work together to destroy microbes and remove debris.

Complement C1 is composed of three subunits: C1q, C1r, and C1s. When activated, C1q binds to the surface of a pathogen or damaged cell, leading to the activation of C1r and C1s. Activated C1r then cleaves and activates C1s, which in turn cleaves and activates other complement components, ultimately resulting in the formation of the membrane attack complex (MAC), a protein structure that forms a pore in the membrane of the target cell, leading to its lysis and destruction.

Defects in the complement component C1 can lead to immune disorders, such as hereditary angioedema, which is characterized by recurrent episodes of swelling in various parts of the body.

Complement C4b is a protein fragment that is formed during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by tagging them for destruction and attracting immune cells to the site of infection or injury.

C4b is generated when the C4 protein is cleaved into two smaller fragments, C4a and C4b, during the activation of the classical or lectin pathways of the complement system. C4b then binds covalently to the surface of the target cell or pathogen, forming a complex with other complement proteins that can create a membrane attack complex (MAC) and cause cell lysis.

C4b can also act as an opsonin, coating the surface of the target cell or pathogen and making it easier for immune cells to recognize and phagocytose them. Additionally, C4b can activate the alternative pathway of the complement system, leading to further amplification of the complement response.

Complement activating enzymes are proteins that play a crucial role in the activation of the complement system, which is a part of the immune system. The complement system is a complex series of biochemical reactions that help to eliminate pathogens and damaged cells from the body.

There are several types of complement activating enzymes, including:

1. Classical pathway activators: These include the C1, C4, and C2 components of the complement system. When activated, they trigger a series of reactions that lead to the formation of the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, leading to its lysis.
2. Alternative pathway activators: These include factors B, D, and P. They are constantly active at low levels and can be activated by surfaces that are not normally found in the body, such as bacterial cell walls. Once activated, they also trigger the formation of the MAC.
3. Lectin pathway activators: These include mannose-binding lectin (MBL) and ficolins. They bind to carbohydrates on the surface of microbes and activate the complement system through the MBL-associated serine proteases (MASPs).

Overall, complement activating enzymes play a critical role in the immune response by helping to identify and eliminate pathogens and damaged cells from the body.

Complement C3d is a protein fragment that is formed during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens such as bacteria and viruses from the body by tagging them for destruction and attracting immune cells to the site of infection.

C3d is a cleavage product of complement component C3, which is one of the central proteins in the complement system. When C3 is activated, it is cleaved into two fragments: C3a and C3b. C3b can then be further cleaved into C3d and C3c.

C3d plays a role in the activation of the immune system by helping to link the complement system with the adaptive immune response. It does this by binding to receptors on B cells, which are a type of white blood cell that produces antibodies. This interaction can help to stimulate the production of antibodies and enhance the immune response to pathogens.

C3d has also been implicated in the development of certain autoimmune diseases, as it can contribute to the formation of immune complexes that can cause tissue damage.

Complement C3-C5 convertases are proteins that play a crucial role in the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by marking them for destruction and attracting immune cells to the site of infection or injury.

The C3-C5 convertases are formed during the activation of the complement component 3 (C3) protein, which is a central player in the complement system. The formation of the C3-C5 convertase involves two main steps:

1. C3 convertase formation: In this step, a complex of proteins called the C3 convertase is formed by the cleavage of C3 into C3a and C3b fragments. This complex can then cleave additional C3 molecules into C3a and C3b fragments, amplifying the complement response.
2. C5 convertase formation: In this step, the C3b fragment from the C3 convertase binds to another protein called C4b2a, forming a new complex called the C5 convertase. The C5 convertase can then cleave the C5 protein into C5a and C5b fragments.

The C5b fragment goes on to form the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, leading to its lysis or destruction. The C3a and C5a fragments are small proteins called anaphylatoxins that can cause inflammation and attract immune cells to the site of infection or injury.

Overall, the formation of Complement C3-C5 convertases is a critical step in the activation of the complement system and plays a key role in the body's defense against pathogens and damaged cells.

Complement fixation tests are a type of laboratory test used in immunology and serology to detect the presence of antibodies in a patient's serum. These tests are based on the principle of complement activation, which is a part of the immune response. The complement system consists of a group of proteins that work together to help eliminate pathogens from the body.

In a complement fixation test, the patient's serum is mixed with a known antigen and complement proteins. If the patient has antibodies against the antigen, they will bind to it and activate the complement system. This results in the consumption or "fixation" of the complement proteins, which are no longer available to participate in a secondary reaction.

A second step involves adding a fresh source of complement proteins and a dye-labeled antibody that recognizes a specific component of the complement system. If complement was fixed during the first step, it will not be available for this secondary reaction, and the dye-labeled antibody will remain unbound. Conversely, if no antibodies were present in the patient's serum, the complement proteins would still be available for the second reaction, leading to the binding of the dye-labeled antibody.

The mixture is then examined under a microscope or using a spectrophotometer to determine whether the dye-labeled antibody has bound. If it has not, this indicates that the patient's serum contains antibodies specific to the antigen used in the test, and a positive result is recorded.

Complement fixation tests have been widely used for the diagnosis of various infectious diseases, such as syphilis, measles, and influenza. However, they have largely been replaced by more modern serological techniques, like enzyme-linked immunosorbent assays (ELISAs) and nucleic acid amplification tests (NAATs), due to their increased sensitivity, specificity, and ease of use.

Complement C7 is a protein that plays a role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, C7 is a component of the membrane attack complex (MAC), which is a group of proteins that forms a pore in the membrane of target cells, leading to their lysis or destruction.

C7 is activated when it binds to the C5b-7 complex, which is formed by the cleavage of C5 and C6 by the C5 convertase. Once bound to the C5b-7 complex, C7 undergoes a conformational change that allows it to insert into the target cell membrane. This forms the basis for the formation of the MAC and subsequent lysis of the target cell.

Deficiencies in complement components, including C7, can lead to increased susceptibility to certain infections and autoimmune disorders. Additionally, abnormal regulation of the complement system has been implicated in a variety of diseases, including inflammatory and degenerative conditions.

Complement C8 is a protein component of the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body. Specifically, C8 is a part of the membrane attack complex (MAC), which forms a pore in the membrane of target cells, leading to their lysis or destruction.

C8 is composed of three subunits: alpha, beta, and gamma. It is activated when it binds to the complement component C5b67 complex on the surface of a target cell. Once activated, C8 undergoes a conformational change that allows it to insert into the target cell membrane and form a pore, which disrupts the cell's membrane integrity and can lead to its death.

Deficiencies in complement components, including C8, can make individuals more susceptible to certain infections and autoimmune diseases. Additionally, mutations in the genes encoding complement proteins have been associated with various inherited disorders, such as atypical hemolytic uremic syndrome (aHUS), which is characterized by thrombotic microangiopathy and kidney failure.

Complement C3c is a protein component of the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Complement C3c is formed when the third component of the complement system (C3) is cleaved into two smaller proteins, C3a and C3b, during the complement activation process.

C3b can then be further cleaved into C3c and C3dg. C3c is a stable fragment that remains in the circulation and can be measured in blood tests as a marker of complement activation. It plays a role in the opsonization of pathogens, which means it coats them to make them more recognizable to immune cells, and helps to initiate the membrane attack complex (MAC), which forms a pore in the cell membrane of pathogens leading to their lysis or destruction.

Abnormal levels of C3c may indicate an underlying inflammatory or immune-mediated condition, such as infection, autoimmune disease, or cancer.

Complement receptor 3d (CR3d or CD11b/CD18) is not a medical definition in itself, but rather a specific type of integrin receptor that plays a crucial role in the immune system. Here's a breakdown of the components:

1. Complement Receptors: These are proteins found on the surface of various cells, including white blood cells (leukocytes), that recognize and bind to complement components, which are proteins involved in the immune response. The binding of complement components to their receptors helps facilitate communication between cells, enhances phagocytosis (the process by which certain cells engulf and destroy foreign particles or microorganisms), and contributes to the inflammatory response.
2. CR3 (Complement Receptor 3): Complement Receptor 3 is a heterodimeric receptor composed of two subunits, CD11b (also known as integrin alpha M) and CD18 (also known as integrin beta 2). Together, they form the integrin Mac-1 or αMβ2.
3. CR3d (CD11b/CD18): CR3d specifically refers to the CD11b subunit of the Complement Receptor 3 heterodimer. The CD11b subunit is responsible for recognizing and binding to complement component C3b, iC3b, and C4b fragments, as well as other ligands such as fibrinogen, ICAM-1 (Intercellular Adhesion Molecule 1), and factor X.

In summary, Complement Receptor 3d (CR3d or CD11b/CD18) is a type of integrin receptor found on the surface of various immune cells that recognizes and binds to complement components C3b, iC3b, and C4b fragments, as well as other ligands. This binding facilitates communication between cells, enhances phagocytosis, and contributes to the inflammatory response.

A Complement Hemolytic Activity Assay is a laboratory test used to measure the functionality and activity level of the complement system, which is a part of the immune system. The complement system is a group of proteins that work together to help eliminate pathogens from the body.

The assay measures the ability of the complement system to lyse (break open) red blood cells. This is done by mixing the patient's serum (the liquid portion of the blood) with antibody-coated red blood cells and incubating them together. The complement proteins in the serum will then bind to the antibodies on the red blood cells and cause them to lyse.

The degree of hemolysis (red blood cell lysis) is directly proportional to the activity level of the complement system. By measuring the amount of hemolysis, the assay can determine whether the complement system is functioning properly and at what level of activity.

This test is often used to diagnose or monitor complement-mediated diseases such as autoimmune disorders, infections, and some types of cancer. It may also be used to evaluate the effectiveness of treatments that target the complement system.

Complement C3b inactivator proteins, also known as complement regulators or decay-accelerating factor (DAF), are a group of proteins that play a crucial role in regulating the complement system. The complement system is a part of the immune system that helps to eliminate pathogens and damaged cells from the body.

The complement C3b inactivator proteins include two main types: complement receptor 1 (CR1) and decay-accelerating factor (DAF). These proteins work by regulating the formation of the membrane attack complex (MAC), a protein structure that forms pores in the cell membrane, leading to cell lysis.

Complement C3b inactivator proteins bind to C3b and C4b components of the complement system, preventing them from forming the MAC. By doing so, they help to prevent excessive activation of the complement system, which can damage healthy cells and tissues.

Deficiencies or dysfunction of complement C3b inactivator proteins have been associated with several diseases, including autoimmune disorders, inflammatory diseases, and infectious diseases. Therefore, understanding the role of these proteins in regulating the complement system is essential for developing new therapies to treat these conditions.

Complement C4a is a protein fragment or cleavage product generated during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells by marking them for destruction and direct lysis. Complement component 4 (C4) is one of the key proteins in this cascade, and it gets cleaved into C4a and C4b during the activation process.

C4a is a small anaphylatoxin with a molecular weight of approximately 9 kDa. It has chemotactic properties, meaning it can attract immune cells like neutrophils to the site of complement activation. Additionally, C4a can induce histamine release from mast cells and basophils, contributing to local inflammation. However, its precise physiological role in the immune response is not entirely clear, and dysregulation of C4a production has been implicated in several pathological conditions, such as autoimmune diseases and allergies.

Complement Factor D is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, Factor D is a serine protease that is involved in the alternative pathway of the complement system.

In this pathway, Factor D helps to cleave another protein called Factor B, which then activates a complex called the C3 convertase. The C3 convertase cleaves complement component 3 (C3) into C3a and C3b, leading to the formation of the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, causing its lysis and removal from the body.

Deficiencies or mutations in Complement Factor D can lead to an impaired alternative pathway and increased susceptibility to certain infections, particularly those caused by Neisseria bacteria. Additionally, abnormal regulation of the complement system has been implicated in a variety of diseases, including autoimmune disorders, inflammatory conditions, and neurodegenerative diseases.

Complement Factor I is a protein involved in the regulation of the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, Complement Factor I is a serine protease that regulates the complement component C3b by cleaving it into inactive fragments, thereby preventing the excessive activation of the complement system and protecting host tissues from damage.

Complement Factor I functions in conjunction with other regulatory proteins, such as complement receptor 1 (CR1) and membrane cofactor protein (MCP), to control the activity of the complement system at various stages. Deficiencies or mutations in Complement Factor I have been associated with several diseases, including atypical hemolytic uremic syndrome (aHUS), age-related macular degeneration (AMD), and systemic lupus erythematosus (SLE).

Complement C4b-binding protein (C4bp) is a regulatory protein in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. C4bp regulates the complement system by binding to and inhibiting the activity of C4b, an activated component of the classical and lectin pathways of the complement system. By doing so, C4bp helps to prevent excessive or inappropriate activation of the complement system, which could otherwise lead to tissue damage and inflammation.

C4bp is a complex protein that consists of several subunits, including a central α-chain and multiple β-chains. It is produced by liver cells and can also be found on the surface of some cells in the body. Mutations in the genes encoding C4bp have been associated with certain immune disorders, such as systemic lupus erythematosus (SLE) and atypical hemolytic uremic syndrome (aHUS).

Complement C1s is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, C1s is a component of the first protein complex in the classical complement pathway, called C1.

C1 is composed of three subunits: C1q, C1r, and C1s. When C1 encounters an activating surface, such as an antibody-antigen complex or certain types of viruses and bacteria, it undergoes a conformational change that allows C1r to cleave and activate C1s. Activated C1s then goes on to cleave and activate other components in the complement pathway, leading to the generation of the membrane attack complex (MAC) and subsequent lysis of the target cell.

Deficiencies or mutations in the genes encoding complement proteins, including C1s, can lead to various immune disorders and increased susceptibility to infections.

Complement C1r is a protein that plays a crucial role in the complement system, which is a part of the immune system that helps to clear pathogens and damaged cells from the body. Specifically, C1r is one of the three proteins that make up the C1 complex, which is the first component of the classical complement pathway.

The C1 complex is composed of C1q, C1r, and C1s, and it is activated by the binding of C1q to the Fc region of an antibody that is bound to a pathogen or damaged cell. Once activated, C1r undergoes a conformational change that allows it to cleave and activate C1s. Activated C1s then goes on to cleave and activate other components of the complement system, leading to the production of the membrane attack complex (MAC), which forms a pore in the membrane of the target cell and causes lysis.

Deficiencies or mutations in the genes encoding the proteins of the C1 complex can lead to immune disorders, including hereditary angioedema, which is characterized by recurrent episodes of swelling in various parts of the body.

CD55, also known as Decay-accelerating factor (DAF), is a protein that acts as an inhibitor of the complement system, which is a part of the immune system. It prevents the formation of the membrane attack complex (MAC) on host cells and tissues, thereby protecting them from damage caused by the complement activation. CD55 is found on the surface of many types of cells in the body, including red blood cells, white blood cells, and cells lining the blood vessels.

As an antigen, CD55 is a molecule that can be recognized by the immune system and stimulate an immune response. However, unlike some other antigens, CD55 does not typically elicit a strong immune response because it is a self-antigen, meaning it is normally present in the body and should not be targeted by the immune system.

In certain medical conditions, such as autoimmune disorders or transplant rejection, the immune system may mistakenly attack cells expressing CD55. In these cases, measuring the levels of CD55 antigens can provide valuable diagnostic information and help guide treatment decisions.

CD59 is a type of protein found on the surface of many cells in the human body, including red and white blood cells, that functions as an inhibitor of the complement system. The complement system is a part of the immune system that helps to eliminate pathogens such as bacteria and viruses from the body.

CD59 specifically inhibits the formation of the membrane attack complex (MAC), which is a protein structure that forms pores in the cell membrane and can lead to cell lysis or death. By preventing the formation of the MAC, CD59 helps to protect cells from complement-mediated damage.

As an antigen, CD59 is a molecule that can be recognized by the immune system and stimulate an immune response. However, because it is a self-protein found on normal human cells, CD59 is not typically targeted by the immune system unless there is some kind of dysregulation or abnormality.

In certain medical conditions, such as autoimmune disorders or transplant rejection, the immune system may mistakenly target CD59 or other self-proteins, leading to damage to healthy cells and tissues. In these cases, treatments may be necessary to modulate or suppress the immune response and prevent further harm.

Complement C1 Inactivator proteins are a part of the complement system, which is a group of proteins in the blood that play a crucial role in the body's immune defense system. Specifically, Complement C1 Inactivator proteins are responsible for regulating the activation of the first component of the complement system, C1.

The complement system is activated in response to the presence of foreign substances such as bacteria or viruses in the body. The activation of C1 leads to a cascade of reactions that result in the destruction of the foreign substance. However, if this process is not properly regulated, it can lead to damage to the body's own cells and tissues.

Complement C1 Inactivator proteins help to prevent this by regulating the activation of C1. They do this by binding to and inhibiting the activity of C1, preventing it from initiating the complement cascade. A deficiency in Complement C1 Inactivator proteins can lead to a condition called hereditary angioedema, which is characterized by recurrent episodes of swelling in various parts of the body.

Complement C5b is a protein complex that forms during the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body by marking them for destruction and attracting immune cells to the site of infection or injury.

The complement component C5 is cleaved into two fragments, C5a and C5b, during the activation of the complement system. C5a is a small peptide that acts as a chemoattractant, drawing immune cells to the site of inflammation. C5b, on the other hand, forms a complex with other complement components (C6, C7, C8, and C9) to create the membrane attack complex (MAC). The MAC inserts itself into the membrane of the target cell, forming a pore that disrupts the cell's integrity and leads to its lysis or destruction.

Therefore, Complement C5b is an important protein involved in the immune response, specifically in the terminal phase of complement activation, which results in the formation of the MAC and subsequent destruction of target cells.

The Mannose-Binding Lectin (MBL) pathway is a part of the complement system, which is a group of proteins that play a crucial role in the body's immune defense against infectious agents. The MBL pathway is an alternative activation pathway of the complement system, which can be initiated without the need for antibodies.

MBL is a protein found in blood plasma and other bodily fluids. It recognizes and binds to specific sugars (mannose and fucose) found on the surface of many microorganisms, including bacteria, viruses, fungi, and parasites. When MBL binds to these sugars, it triggers a series of proteolytic cleavage events that activate the complement components C4 and C2, forming the C3 convertase (C4b2a).

The C3 convertase then cleaves the complement component C3 into C3a and C3b. C3b can bind to the surface of microorganisms, leading to their opsonization (coating) and subsequent phagocytosis by immune cells. Additionally, C3b can also trigger the formation of the membrane attack complex (MAC), which creates a pore in the membrane of microorganisms, leading to their lysis and death.

Overall, the MBL pathway plays an essential role in innate immunity, providing a rapid and effective defense against invading microorganisms.

Properdin is defined as a positive regulatory protein in the complement system, which is a part of the immune system. It plays a crucial role in the alternative pathway of complement activation. Properdin stabilizes the C3 convertase (C3bBb), preventing its decay and increasing the efficiency of the alternative pathway. This results in the production of the membrane attack complex, which leads to the lysis of foreign cells or pathogens. Deficiencies in properdin can lead to an increased susceptibility to bacterial infections.

Cobra venoms are a type of snake venom that is produced by cobras, which are members of the genus Naja in the family Elapidae. These venoms are complex mixtures of proteins and other molecules that have evolved to help the snake immobilize and digest its prey.

Cobra venoms typically contain a variety of toxic components, including neurotoxins, hemotoxins, and cytotoxins. Neurotoxins target the nervous system and can cause paralysis and respiratory failure. Hemotoxins damage blood vessels and tissues, leading to internal bleeding and organ damage. Cytotoxins destroy cells and can cause tissue necrosis.

The specific composition of cobra venoms can vary widely between different species of cobras, as well as between individual snakes of the same species. Some cobras have venoms that are primarily neurotoxic, while others have venoms that are more hemotoxic or cytotoxic. The potency and effects of cobra venoms can also be influenced by factors such as the age and size of the snake, as well as the temperature and pH of the environment.

Cobra bites can be extremely dangerous and even fatal to humans, depending on the species of cobra, the amount of venom injected, and the location of the bite. Immediate medical attention is required in the event of a cobra bite, including the administration of antivenom therapy to neutralize the effects of the venom.

Hemolysis is the destruction or breakdown of red blood cells, resulting in the release of hemoglobin into the surrounding fluid (plasma). This process can occur due to various reasons such as chemical agents, infections, autoimmune disorders, mechanical trauma, or genetic abnormalities. Hemolysis may lead to anemia and jaundice, among other complications. It is essential to monitor hemolysis levels in patients undergoing medical treatments that might cause this condition.

The Complement C1 Inhibitor protein, also known as C1-INH, is a protein involved in the regulation of the complement system and the contact system, which are parts of the immune system. The complement system helps to eliminate pathogens (e.g., bacteria, viruses) from the body, while the contact system helps to regulate blood coagulation and inflammation.

C1-INH works by inhibiting the activation of C1, an enzyme complex that is the first component of the classical complement pathway. By inhibiting C1, C1-INH prevents the activation of downstream components of the complement system, thereby helping to regulate the immune response and prevent excessive inflammation.

Deficiencies or dysfunction in the C1-INH protein can lead to a group of genetic disorders known as C1 inhibitor deficiency disorders, which include hereditary angioedema (HAE) and acquired angioedema (AAE). These conditions are characterized by recurrent episodes of swelling in various parts of the body, such as the face, hands, feet, and airway, which can be painful and potentially life-threatening if they affect the airway.

Anaphylatoxins are a group of small protein molecules that are released during an immune response, specifically as a result of the activation of the complement system. The term "anaphylatoxin" comes from their ability to induce anaphylaxis, a severe and rapid allergic reaction. There are three main anaphylatoxins, known as C3a, C4a, and C5a, which are derived from the cleavage of complement components C3, C4, and C5, respectively.

Anaphylatoxins play a crucial role in the immune response by attracting and activating various immune cells, such as neutrophils, eosinophils, and mast cells, to the site of infection or injury. They also increase vascular permeability, causing fluid to leak out of blood vessels and leading to tissue swelling. Additionally, anaphylatoxins can induce smooth muscle contraction, which can result in bronchoconstriction and hypotension.

While anaphylatoxins are important for the immune response, they can also contribute to the pathogenesis of various inflammatory diseases, such as asthma, arthritis, and sepsis. Therefore, therapies that target the complement system and anaphylatoxin production have been developed and are being investigated as potential treatments for these conditions.

Complement C3 Convertase, Alternative Pathway is a complex enzyme composed of the proteins C3b and Bb. It plays a crucial role in the alternative pathway of the complement system, which is a part of the innate immune system that helps to defend the body against invading pathogens.

The alternative pathway is continuously activated at a low level, and C3 Convertase is responsible for amplifying this activation. It does so by cleaving the complement component C3 into C3a and C3b. The C3b then binds to the surface of the pathogen and can form additional C3 Convertases, leading to a positive feedback loop that results in the rapid accumulation of complement components on the surface of the pathogen.

This accumulation of complement components helps to mark the pathogen for destruction by other immune cells, such as neutrophils and macrophages. Additionally, the cleavage products C3a and C5a generated during this process can act as anaphylatoxins, inducing inflammation and attracting more immune cells to the site of infection.

Regulation of Complement C3 Convertase is critical to prevent damage to host tissues. Several regulatory proteins, such as factor H and decay-accelerating factor (DAF), help to limit the formation and activity of C3 Convertase on host cells and tissues. Dysregulation of the complement system, including the alternative pathway and Complement C3 Convertase, has been implicated in a variety of diseases, including autoimmune disorders, inflammatory diseases, and infectious diseases.

CD46, also known as membrane cofactor protein (MCP), is a regulatory protein that plays a role in the immune system and helps to protect cells from complement activation. It is found on the surface of many different types of cells in the body, including cells of the immune system such as T cells and B cells, as well as cells of various other tissues such as epithelial cells and endothelial cells.

As an antigen, CD46 is a molecule that can be recognized by the immune system and stimulate an immune response. It is a type I transmembrane protein that consists of four distinct domains: two short cytoplasmic domains, a transmembrane domain, and a large extracellular domain. The extracellular domain contains several binding sites for complement proteins, which helps to regulate the activation of the complement system and prevent it from damaging host cells.

CD46 has been shown to play a role in protecting cells from complement-mediated damage, modulating immune responses, and promoting the survival and proliferation of certain types of immune cells. It is also thought to be involved in the development of some autoimmune diseases and may be a target for immunotherapy in the treatment of cancer.

The term "Receptor, Anaphylatoxin C5a" refers to a specific type of receptor found on the surface of various cells in the human body, including immune cells and endothelial cells. This receptor binds to a molecule called C5a, which is a cleavage product of the complement component C5 and is one of the most potent anaphylatoxins.

Anaphylatoxins are inflammatory mediators that play a crucial role in the immune response, particularly in the activation of the complement system and the recruitment of immune cells to sites of infection or injury. C5a is generated during the activation of the complement system and has a wide range of biological activities, including chemotaxis (attracting immune cells to the site of inflammation), increased vascular permeability, and the activation of immune cells such as neutrophils, monocytes, and mast cells.

The C5a receptor, also known as CD88, is a G protein-coupled receptor that belongs to the superfamily of seven transmembrane domain receptors. When C5a binds to the receptor, it triggers a series of intracellular signaling events that lead to the activation of various cellular responses, such as the release of inflammatory mediators and the recruitment of immune cells to the site of inflammation.

Abnormal activation of the C5a/C5a receptor pathway has been implicated in a variety of inflammatory diseases, including sepsis, acute respiratory distress syndrome (ARDS), and autoimmune disorders. Therefore, targeting this pathway with therapeutic agents has emerged as a promising strategy for the treatment of these conditions.

A genetic complementation test is a laboratory procedure used in molecular genetics to determine whether two mutated genes can complement each other's function, indicating that they are located at different loci and represent separate alleles. This test involves introducing a normal or wild-type copy of one gene into a cell containing a mutant version of the same gene, and then observing whether the presence of the normal gene restores the normal function of the mutated gene. If the introduction of the normal gene results in the restoration of the normal phenotype, it suggests that the two genes are located at different loci and can complement each other's function. However, if the introduction of the normal gene does not restore the normal phenotype, it suggests that the two genes are located at the same locus and represent different alleles of the same gene. This test is commonly used to map genes and identify genetic interactions in a variety of organisms, including bacteria, yeast, and animals.

An antigen-antibody complex is a type of immune complex that forms when an antibody binds to a specific antigen. An antigen is any substance that triggers an immune response, while an antibody is a protein produced by the immune system to neutralize or destroy foreign substances like antigens.

When an antibody binds to an antigen, it forms a complex that can be either soluble or insoluble. Soluble complexes are formed when the antigen is small and can move freely through the bloodstream. Insoluble complexes, on the other hand, are formed when the antigen is too large to move freely, such as when it is part of a bacterium or virus.

The formation of antigen-antibody complexes plays an important role in the immune response. Once formed, these complexes can be recognized and cleared by other components of the immune system, such as phagocytes, which help to prevent further damage to the body. However, in some cases, the formation of large numbers of antigen-antibody complexes can lead to inflammation and tissue damage, contributing to the development of certain autoimmune diseases.

Opsonins are proteins found in the blood that help enhance the immune system's response to foreign substances, such as bacteria and viruses. They do this by coating the surface of these pathogens, making them more recognizable to immune cells like neutrophils and macrophages. This process, known as opsonization, facilitates the phagocytosis (engulfing and destroying) of the pathogen by these immune cells.

There are two main types of opsonins:

1. IgG antibodies: These are a type of antibody produced by the immune system in response to an infection. They bind to specific antigens on the surface of the pathogen, marking them for destruction by phagocytic cells.
2. Complement proteins: The complement system is a group of proteins that work together to help eliminate pathogens. When activated, the complement system can produce various proteins that act as opsonins, including C3b and C4b. These proteins bind to the surface of the pathogen, making it easier for phagocytic cells to recognize and destroy them.

In summary, opsonin proteins are crucial components of the immune system's response to infections, helping to mark foreign substances for destruction by immune cells like neutrophils and macrophages.

Immunoglobulin G (IgG) is a type of antibody, which is a protective protein produced by the immune system in response to foreign substances like bacteria or viruses. IgG is the most abundant type of antibody in human blood, making up about 75-80% of all antibodies. It is found in all body fluids and plays a crucial role in fighting infections caused by bacteria, viruses, and toxins.

IgG has several important functions:

1. Neutralization: IgG can bind to the surface of bacteria or viruses, preventing them from attaching to and infecting human cells.
2. Opsonization: IgG coats the surface of pathogens, making them more recognizable and easier for immune cells like neutrophils and macrophages to phagocytose (engulf and destroy) them.
3. Complement activation: IgG can activate the complement system, a group of proteins that work together to help eliminate pathogens from the body. Activation of the complement system leads to the formation of the membrane attack complex, which creates holes in the cell membranes of bacteria, leading to their lysis (destruction).
4. Antibody-dependent cellular cytotoxicity (ADCC): IgG can bind to immune cells like natural killer (NK) cells and trigger them to release substances that cause target cells (such as virus-infected or cancerous cells) to undergo apoptosis (programmed cell death).
5. Immune complex formation: IgG can form immune complexes with antigens, which can then be removed from the body through various mechanisms, such as phagocytosis by immune cells or excretion in urine.

IgG is a critical component of adaptive immunity and provides long-lasting protection against reinfection with many pathogens. It has four subclasses (IgG1, IgG2, IgG3, and IgG4) that differ in their structure, function, and distribution in the body.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Phagocytosis is the process by which certain cells in the body, known as phagocytes, engulf and destroy foreign particles, bacteria, or dead cells. This mechanism plays a crucial role in the immune system's response to infection and inflammation. Phagocytes, such as neutrophils, monocytes, and macrophages, have receptors on their surface that recognize and bind to specific molecules (known as antigens) on the target particles or microorganisms.

Once attached, the phagocyte extends pseudopodia (cell extensions) around the particle, forming a vesicle called a phagosome that completely encloses it. The phagosome then fuses with a lysosome, an intracellular organelle containing digestive enzymes and other chemicals. This fusion results in the formation of a phagolysosome, where the engulfed particle is broken down by the action of these enzymes, neutralizing its harmful effects and allowing for the removal of cellular debris or pathogens.

Phagocytosis not only serves as a crucial defense mechanism against infections but also contributes to tissue homeostasis by removing dead cells and debris.

Blood bactericidal activity refers to the ability of an individual's blood to kill or inhibit the growth of bacteria. This is an important aspect of the body's immune system, as it helps to prevent infection and maintain overall health. The bactericidal activity of blood can be influenced by various factors, including the presence of antibodies, white blood cells (such as neutrophils), and complement proteins.

In medical terms, the term "bactericidal" specifically refers to an agent or substance that is capable of killing bacteria. Therefore, when we talk about blood bactericidal activity, we are referring to the collective ability of various components in the blood to kill or inhibit the growth of bacteria. This is often measured in laboratory tests as a way to assess a person's immune function and their susceptibility to infection.

It's worth noting that not all substances in the blood are bactericidal; some may simply inhibit the growth of bacteria without killing them. These substances are referred to as bacteriostatic. Both bactericidal and bacteriostatic agents play important roles in maintaining the body's defense against infection.

Mannose-Binding Lectin (MBL) is a protein that belongs to the collectin family and plays a crucial role in the innate immune system. It's primarily produced by the liver and secreted into the bloodstream. MBL binds to carbohydrate structures, such as mannose, found on the surface of various microorganisms, including bacteria, viruses, fungi, and parasites.

Once MBL binds to these microorganisms, it activates the complement system through the lectin pathway, which leads to the destruction of the pathogens by opsonization (marking for phagocytosis) or direct lysis. Additionally, MBL can also initiate other immune responses, such as inflammation and immune cell activation, helping to protect the host from infections.

Deficiencies in MBL have been associated with increased susceptibility to certain infectious diseases, autoimmune disorders, and allergies. However, more research is needed to fully understand the complex role of MBL in human health and disease.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

The Macrophage-1 Antigen (also known as Macrophage Antigen-1 or CD14) is a glycoprotein found on the surface of various cells, including monocytes, macrophages, and some dendritic cells. It functions as a receptor for complexes formed by lipopolysaccharides (LPS) and LPS-binding protein (LBP), which are involved in the immune response to gram-negative bacteria. CD14 plays a crucial role in activating immune cells and initiating the release of proinflammatory cytokines upon recognizing bacterial components.

In summary, Macrophage-1 Antigen is a cell surface receptor that contributes to the recognition and response against gram-negative bacteria by interacting with LPS-LBP complexes.

Erythrocytes, also known as red blood cells (RBCs), are the most common type of blood cell in circulating blood in mammals. They are responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.

Erythrocytes are formed in the bone marrow and have a biconcave shape, which allows them to fold and bend easily as they pass through narrow blood vessels. They do not have a nucleus or mitochondria, which makes them more flexible but also limits their ability to reproduce or repair themselves.

In humans, erythrocytes are typically disc-shaped and measure about 7 micrometers in diameter. They contain the protein hemoglobin, which binds to oxygen and gives blood its red color. The lifespan of an erythrocyte is approximately 120 days, after which it is broken down in the liver and spleen.

Abnormalities in erythrocyte count or function can lead to various medical conditions, such as anemia, polycythemia, and sickle cell disease.

Mannose-binding protein-associated serine proteases (MASPs) are a group of enzymes that are associated with mannose-binding lectin (MBL), a protein involved in the innate immune system's response to pathogens. MASPs are responsible for activating the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells from the body.

MASPs are proteases, meaning they cleave other proteins at specific sites. There are two main types of MASPs, MASP-1 and MASP-2, which are activated by the binding of MBL to carbohydrate structures on the surface of pathogens. Once activated, MASP-1 and MASP-2 cleave complement components C4 and C2, leading to the formation of the C3 convertase enzyme complex, which ultimately results in the activation of the complement system.

MASPs have also been shown to play a role in other physiological processes, such as tissue remodeling and inflammation. Mutations in MASP genes have been associated with various immune disorders, including recurrent infections, autoimmune diseases, and inflammatory conditions.

Zymosan is a type of substance that is derived from the cell walls of yeast and some types of fungi. It's often used in laboratory research as an agent to stimulate inflammation, because it can activate certain immune cells (such as neutrophils) and cause them to release pro-inflammatory chemicals.

In medical terms, Zymosan is sometimes used as a tool for studying the immune system and inflammation in experimental settings. It's important to note that Zymosan itself is not a medical condition or disease, but rather a research reagent with potential applications in understanding human health and disease.

Immunoglobulin M (IgM) is a type of antibody that is primarily found in the blood and lymph fluid. It is the first antibody to be produced in response to an initial exposure to an antigen, making it an important part of the body's primary immune response. IgM antibodies are large molecules that are composed of five basic units, giving them a pentameric structure. They are primarily found on the surface of B cells as membrane-bound immunoglobulins (mlgM), where they function as receptors for antigens. Once an mlgM receptor binds to an antigen, it triggers the activation and differentiation of the B cell into a plasma cell that produces and secretes large amounts of soluble IgM antibodies.

IgM antibodies are particularly effective at agglutination (clumping) and complement activation, which makes them important in the early stages of an immune response to help clear pathogens from the bloodstream. However, they are not as stable or long-lived as other types of antibodies, such as IgG, and their levels tend to decline after the initial immune response has occurred.

In summary, Immunoglobulin M (IgM) is a type of antibody that plays a crucial role in the primary immune response to antigens by agglutination and complement activation. It is primarily found in the blood and lymph fluid, and it is produced by B cells after they are activated by an antigen.

Complement C5a, des-Arginine is a derivative of the complement component C5a. The complement system is a group of proteins that are part of the body's immune defense against foreign invaders such as bacteria and viruses. When activated, the complement system can help to eliminate pathogens by attracting immune cells to the site of infection, promoting inflammation, and directly killing the pathogen.

C5a is a small protein that is generated when the complement component C5 is cleaved during the activation of the complement system. C5a is a potent anaphylatoxin, which means it can cause the release of histamine from mast cells and basophils, leading to increased vascular permeability, smooth muscle contraction, and recruitment of immune cells to the site of infection.

Des-Arginine refers to the removal of an arginine residue from the C-terminus of C5a. This modified form of C5a is known as C5a-desArg and has reduced pro-inflammatory activity compared to intact C5a. However, it can still contribute to the regulation of the immune response by interacting with specific receptors on immune cells.

In summary, Complement C5a, des-Arginine is a derivative of the complement component C5a that has reduced pro-inflammatory activity due to the removal of an arginine residue from its C-terminus.

Neutrophils are a type of white blood cell that are part of the immune system's response to infection. They are produced in the bone marrow and released into the bloodstream where they circulate and are able to move quickly to sites of infection or inflammation in the body. Neutrophils are capable of engulfing and destroying bacteria, viruses, and other foreign substances through a process called phagocytosis. They are also involved in the release of inflammatory mediators, which can contribute to tissue damage in some cases. Neutrophils are characterized by the presence of granules in their cytoplasm, which contain enzymes and other proteins that help them carry out their immune functions.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Monoclonal antibodies are a type of antibody that are identical because they are produced by a single clone of cells. They are laboratory-produced molecules that act like human antibodies in the immune system. They can be designed to attach to specific proteins found on the surface of cancer cells, making them useful for targeting and treating cancer. Monoclonal antibodies can also be used as a therapy for other diseases, such as autoimmune disorders and inflammatory conditions.

Monoclonal antibodies are produced by fusing a single type of immune cell, called a B cell, with a tumor cell to create a hybrid cell, or hybridoma. This hybrid cell is then able to replicate indefinitely, producing a large number of identical copies of the original antibody. These antibodies can be further modified and engineered to enhance their ability to bind to specific targets, increase their stability, and improve their effectiveness as therapeutic agents.

Monoclonal antibodies have several mechanisms of action in cancer therapy. They can directly kill cancer cells by binding to them and triggering an immune response. They can also block the signals that promote cancer growth and survival. Additionally, monoclonal antibodies can be used to deliver drugs or radiation directly to cancer cells, increasing the effectiveness of these treatments while minimizing their side effects on healthy tissues.

Monoclonal antibodies have become an important tool in modern medicine, with several approved for use in cancer therapy and other diseases. They are continuing to be studied and developed as a promising approach to treating a wide range of medical conditions.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

Antibodies are proteins produced by the immune system in response to the presence of a foreign substance, such as a bacterium or virus. They are capable of identifying and binding to specific antigens (foreign substances) on the surface of these invaders, marking them for destruction by other immune cells. Antibodies are also known as immunoglobulins and come in several different types, including IgA, IgD, IgE, IgG, and IgM, each with a unique function in the immune response. They are composed of four polypeptide chains, two heavy chains and two light chains, that are held together by disulfide bonds. The variable regions of the heavy and light chains form the antigen-binding site, which is specific to a particular antigen.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

Collectins are a group of proteins that belong to the collectin family, which are involved in the innate immune system. They are composed of a collagen-like region and a carbohydrate recognition domain (CRD), which allows them to bind to specific sugars on the surface of microorganisms, cells, and particles. Collectins play a crucial role in the defense against pathogens by promoting the clearance of microbes, modulating inflammation, and regulating immune responses.

Some examples of collectins include:

* Surfactant protein A (SP-A) and surfactant protein D (SP-D), which are found in the lungs and help to maintain the stability of the lung lining and protect against respiratory infections.
* Mannose-binding lectin (MBL), which is a serum protein that binds to mannose sugars on the surface of microorganisms, activating the complement system and promoting phagocytosis.
* Collectin liver 1 (CL-L1) and collectin kidney 1 (CL-K1), which are found in the liver and kidneys, respectively, and play a role in the clearance of apoptotic cells and immune complexes.

Deficiencies or mutations in collectins can lead to increased susceptibility to infections, autoimmune diseases, and other disorders.

C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.

The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.

C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.

One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.

Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.

Macular degeneration, also known as age-related macular degeneration (AMD), is a medical condition that affects the central part of the retina, called the macula. The macula is responsible for sharp, detailed vision, which is necessary for activities such as reading, driving, and recognizing faces.

In AMD, there is a breakdown or deterioration of the macula, leading to gradual loss of central vision. There are two main types of AMD: dry (atrophic) and wet (exudative). Dry AMD is more common and progresses more slowly, while wet AMD is less common but can cause rapid and severe vision loss if left untreated.

The exact causes of AMD are not fully understood, but risk factors include age, smoking, family history, high blood pressure, obesity, and exposure to sunlight. While there is no cure for AMD, treatments such as vitamin supplements, laser therapy, and medication injections can help slow its progression and reduce the risk of vision loss.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

Blood proteins, also known as serum proteins, are a group of complex molecules present in the blood that are essential for various physiological functions. These proteins include albumin, globulins (alpha, beta, and gamma), and fibrinogen. They play crucial roles in maintaining oncotic pressure, transporting hormones, enzymes, vitamins, and minerals, providing immune defense, and contributing to blood clotting.

Albumin is the most abundant protein in the blood, accounting for about 60% of the total protein mass. It functions as a transporter of various substances, such as hormones, fatty acids, and drugs, and helps maintain oncotic pressure, which is essential for fluid balance between the blood vessels and surrounding tissues.

Globulins are divided into three main categories: alpha, beta, and gamma globulins. Alpha and beta globulins consist of transport proteins like lipoproteins, hormone-binding proteins, and enzymes. Gamma globulins, also known as immunoglobulins or antibodies, are essential for the immune system's defense against pathogens.

Fibrinogen is a protein involved in blood clotting. When an injury occurs, fibrinogen is converted into fibrin, which forms a mesh to trap platelets and form a clot, preventing excessive bleeding.

Abnormal levels of these proteins can indicate various medical conditions, such as liver or kidney disease, malnutrition, infections, inflammation, or autoimmune disorders. Blood protein levels are typically measured through laboratory tests like serum protein electrophoresis (SPE) and immunoelectrophoresis (IEP).

Bacterial proteins are a type of protein that are produced by bacteria as part of their structural or functional components. These proteins can be involved in various cellular processes, such as metabolism, DNA replication, transcription, and translation. They can also play a role in bacterial pathogenesis, helping the bacteria to evade the host's immune system, acquire nutrients, and multiply within the host.

Bacterial proteins can be classified into different categories based on their function, such as:

1. Enzymes: Proteins that catalyze chemical reactions in the bacterial cell.
2. Structural proteins: Proteins that provide structural support and maintain the shape of the bacterial cell.
3. Signaling proteins: Proteins that help bacteria to communicate with each other and coordinate their behavior.
4. Transport proteins: Proteins that facilitate the movement of molecules across the bacterial cell membrane.
5. Toxins: Proteins that are produced by pathogenic bacteria to damage host cells and promote infection.
6. Surface proteins: Proteins that are located on the surface of the bacterial cell and interact with the environment or host cells.

Understanding the structure and function of bacterial proteins is important for developing new antibiotics, vaccines, and other therapeutic strategies to combat bacterial infections.

I must clarify that the term "Guinea Pigs" is not typically used in medical definitions. However, in colloquial or informal language, it may refer to people who are used as the first to try out a new medical treatment or drug. This is known as being a "test subject" or "in a clinical trial."

In the field of scientific research, particularly in studies involving animals, guinea pigs are small rodents that are often used as experimental subjects due to their size, cost-effectiveness, and ease of handling. They are not actually pigs from Guinea, despite their name's origins being unclear. However, they do not exactly fit the description of being used in human medical experiments.

The term "Immune Adherence Reaction" is not widely used in modern immunology or medicine. It appears to be an outdated concept that refers to the attachment of immune complexes (consisting of antigens, antibodies, and complement components) to Fc receptors on phagocytic cells, such as neutrophils and monocytes. This interaction facilitates the clearance of immune complexes from circulation and helps to prevent tissue damage caused by their deposition.

However, it is important to note that this term is not commonly used in current scientific literature or clinical settings. Instead, the processes it describes are typically discussed within the broader context of immune complex-mediated inflammation, complement activation, and phagocytosis.

An Enzyme-Linked Immunosorbent Assay (ELISA) is a type of analytical biochemistry assay used to detect and quantify the presence of a substance, typically a protein or peptide, in a liquid sample. It takes its name from the enzyme-linked antibodies used in the assay.

In an ELISA, the sample is added to a well containing a surface that has been treated to capture the target substance. If the target substance is present in the sample, it will bind to the surface. Next, an enzyme-linked antibody specific to the target substance is added. This antibody will bind to the captured target substance if it is present. After washing away any unbound material, a substrate for the enzyme is added. If the enzyme is present due to its linkage to the antibody, it will catalyze a reaction that produces a detectable signal, such as a color change or fluorescence. The intensity of this signal is proportional to the amount of target substance present in the sample, allowing for quantification.

ELISAs are widely used in research and clinical settings to detect and measure various substances, including hormones, viruses, and bacteria. They offer high sensitivity, specificity, and reproducibility, making them a reliable choice for many applications.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

Immunoelectrophoresis (IEP) is a laboratory technique used in the field of clinical pathology and immunology. It is a method for separating and identifying proteins, particularly immunoglobulins or antibodies, in a sample. This technique combines the principles of electrophoresis, which separates proteins based on their electric charge and size, with immunological reactions, which detect specific proteins using antigen-antibody interactions.

In IEP, a protein sample is first separated by electrophoresis in an agarose or agar gel matrix on a glass slide or in a test tube. After separation, an antibody specific to the protein of interest is layered on top of the gel and allowed to diffuse towards the separated proteins. This creates a reaction between the antigen (protein) and the antibody, forming a visible precipitate at the point where they meet. The precipitate line's position and intensity can then be analyzed to identify and quantify the protein of interest.

Immunoelectrophoresis is particularly useful in diagnosing various medical conditions, such as immunodeficiency disorders, monoclonal gammopathies (like multiple myeloma), and other plasma cell dyscrasias. It can help detect abnormal protein patterns, quantify specific immunoglobulins, and identify the presence of M-proteins or Bence Jones proteins, which are indicative of monoclonal gammopathies.

Bacterial antibodies are a type of antibodies produced by the immune system in response to an infection caused by bacteria. These antibodies are proteins that recognize and bind to specific antigens on the surface of the bacterial cells, marking them for destruction by other immune cells. Bacterial antibodies can be classified into several types based on their structure and function, including IgG, IgM, IgA, and IgE. They play a crucial role in the body's defense against bacterial infections and provide immunity to future infections with the same bacteria.

A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.

The Fluorescent Antibody Technique (FAT) is a type of immunofluorescence assay used in laboratory medicine and pathology for the detection and localization of specific antigens or antibodies in tissues, cells, or microorganisms. In this technique, a fluorescein-labeled antibody is used to selectively bind to the target antigen or antibody, forming an immune complex. When excited by light of a specific wavelength, the fluorescein label emits light at a longer wavelength, typically visualized as green fluorescence under a fluorescence microscope.

The FAT is widely used in diagnostic microbiology for the identification and characterization of various bacteria, viruses, fungi, and parasites. It has also been applied in the diagnosis of autoimmune diseases and certain cancers by detecting specific antibodies or antigens in patient samples. The main advantage of FAT is its high sensitivity and specificity, allowing for accurate detection and differentiation of various pathogens and disease markers. However, it requires specialized equipment and trained personnel to perform and interpret the results.

Glomerulonephritis is a medical condition that involves inflammation of the glomeruli, which are the tiny blood vessel clusters in the kidneys that filter waste and excess fluids from the blood. This inflammation can impair the kidney's ability to filter blood properly, leading to symptoms such as proteinuria (protein in the urine), hematuria (blood in the urine), edema (swelling), hypertension (high blood pressure), and eventually kidney failure.

Glomerulonephritis can be acute or chronic, and it may occur as a primary kidney disease or secondary to other medical conditions such as infections, autoimmune disorders, or vasculitis. The diagnosis of glomerulonephritis typically involves a combination of medical history, physical examination, urinalysis, blood tests, and imaging studies, with confirmation often requiring a kidney biopsy. Treatment depends on the underlying cause and severity of the disease but may include medications to suppress inflammation, control blood pressure, and manage symptoms.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired disorder of the blood characterized by the destruction of red blood cells (hemolysis), which can cause symptoms such as fatigue, dark colored urine (especially in the morning), chest pain, shortness of breath, and an increased risk of blood clots. The hemoglobin from the lysed red blood cells appears in the urine, hence the term "hemoglobinuria."

The paroxysmal nature of the disorder refers to the sudden and recurring episodes of hemolysis that can occur at any time, although they may be more frequent at night. The condition is caused by mutations in a gene called PIG-A, which leads to the production of defective red blood cell membranes that are sensitive to destruction by complement, a component of the immune system.

PNH is a serious and potentially life-threatening condition that can lead to complications such as kidney damage, pulmonary hypertension, and thrombosis. Treatment typically involves supportive care, such as blood transfusions, and medications to manage symptoms and prevent complications. In some cases, stem cell transplantation may be considered as a curative treatment option.

Immune complex diseases are medical conditions that occur when the immune system produces an abnormal response to certain antigens, leading to the formation and deposition of immune complexes in various tissues and organs. These immune complexes consist of antibodies bound to antigens, which can trigger an inflammatory reaction and damage the surrounding tissue.

Immune complex diseases can be classified into two categories: acute and chronic. Acute immune complex diseases include serum sickness and hypersensitivity vasculitis, while chronic immune complex diseases include systemic lupus erythematosus (SLE), rheumatoid arthritis, and membranoproliferative glomerulonephritis.

The symptoms of immune complex diseases depend on the location and extent of tissue damage. They can range from mild to severe and may include fever, joint pain, skin rashes, kidney dysfunction, and neurological problems. Treatment typically involves medications that suppress the immune system and reduce inflammation, such as corticosteroids, immunosuppressants, and anti-inflammatory drugs.

Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by the immune system's B cells in response to the presence of foreign substances, such as bacteria, viruses, and toxins. These Y-shaped proteins play a crucial role in identifying and neutralizing pathogens and other antigens, thereby protecting the body against infection and disease.

Immunoglobulins are composed of four polypeptide chains: two identical heavy chains and two identical light chains, held together by disulfide bonds. The variable regions of these chains form the antigen-binding sites, which recognize and bind to specific epitopes on antigens. Based on their heavy chain type, immunoglobulins are classified into five main isotypes or classes: IgA, IgD, IgE, IgG, and IgM. Each class has distinct functions in the immune response, such as providing protection in different body fluids and tissues, mediating hypersensitivity reactions, and aiding in the development of immunological memory.

In medical settings, immunoglobulins can be administered therapeutically to provide passive immunity against certain diseases or to treat immune deficiencies, autoimmune disorders, and other conditions that may benefit from immunomodulation.

"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.

Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.

It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.

Systemic Lupus Erythematosus (SLE) is a complex autoimmune disease that can affect almost any organ or system in the body. In SLE, the immune system produces an exaggerated response, leading to the production of autoantibodies that attack the body's own cells and tissues, causing inflammation and damage. The symptoms and severity of SLE can vary widely from person to person, but common features include fatigue, joint pain, skin rashes (particularly a "butterfly" rash across the nose and cheeks), fever, hair loss, and sensitivity to sunlight.

Systemic lupus erythematosus can also affect the kidneys, heart, lungs, brain, blood vessels, and other organs, leading to a wide range of symptoms such as kidney dysfunction, chest pain, shortness of breath, seizures, and anemia. The exact cause of SLE is not fully understood, but it is believed to involve a combination of genetic, environmental, and hormonal factors. Treatment typically involves medications to suppress the immune system and manage symptoms, and may require long-term management by a team of healthcare professionals.

Recombinant proteins are artificially created proteins produced through the use of recombinant DNA technology. This process involves combining DNA molecules from different sources to create a new set of genes that encode for a specific protein. The resulting recombinant protein can then be expressed, purified, and used for various applications in research, medicine, and industry.

Recombinant proteins are widely used in biomedical research to study protein function, structure, and interactions. They are also used in the development of diagnostic tests, vaccines, and therapeutic drugs. For example, recombinant insulin is a common treatment for diabetes, while recombinant human growth hormone is used to treat growth disorders.

The production of recombinant proteins typically involves the use of host cells, such as bacteria, yeast, or mammalian cells, which are engineered to express the desired protein. The host cells are transformed with a plasmid vector containing the gene of interest, along with regulatory elements that control its expression. Once the host cells are cultured and the protein is expressed, it can be purified using various chromatography techniques.

Overall, recombinant proteins have revolutionized many areas of biology and medicine, enabling researchers to study and manipulate proteins in ways that were previously impossible.

Immunodiffusion is a laboratory technique used in immunology to detect and measure the presence of specific antibodies or antigens in a sample. It is based on the principle of diffusion, where molecules move from an area of high concentration to an area of low concentration until they reach equilibrium. In this technique, a sample containing an unknown quantity of antigen or antibody is placed in a gel or agar medium that contains a known quantity of antibody or antigen, respectively.

The two substances then diffuse towards each other and form a visible precipitate at the point where they meet and reach equivalence, which indicates the presence and quantity of the specific antigen or antibody in the sample. There are several types of immunodiffusion techniques, including radial immunodiffusion (RID) and double immunodiffusion (Ouchterlony technique). These techniques are widely used in diagnostic laboratories to identify and measure various antigens and antibodies, such as those found in infectious diseases, autoimmune disorders, and allergic reactions.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Complement C2b is a proteolytic fragment generated through the activation of the complement component C2, which is a part of the complement system. The complement system is a group of plasma proteins that play an important role in the body's immune defense against pathogens and abnormal cells.

When the complement component C2 is activated by the C3 convertase (a complex formed by C3b and either C4b or C4d), it is cleaved into two fragments: C2a and C2b. The C2b fragment is a smaller piece that contains an active protease domain, which can cleave other proteins in the complement pathway.

C2b plays a role in the formation of the membrane attack complex (MAC), a protein structure that forms pores in the membranes of target cells, leading to their lysis and removal by the immune system. Dysregulation or overactivation of the complement system, including C2b, can contribute to various pathological conditions such as autoimmune diseases, inflammatory disorders, and tissue damage.

Cryoglobulins are immunoglobulins (a type of antibody) that precipitate or become insoluble at reduced temperatures, typically below 37°C (98.6°F), and re-dissolve when rewarmed. They can be found in various clinical conditions such as infections, inflammatory diseases, and lymphoproliferative disorders.

The presence of cryoglobulins in the blood can lead to a variety of symptoms, including purpura (a type of skin rash), arthralgias (joint pain), neuropathy (nerve damage), and glomerulonephritis (kidney inflammation). The diagnosis of cryoglobulinemia is made by detecting the presence of cryoglobulins in the serum, which requires special handling and processing of the blood sample. Treatment of cryoglobulinemia depends on the underlying cause and may include medications such as corticosteroids, immunosuppressive agents, or targeted therapies.

Lectins are a type of proteins that bind specifically to carbohydrates and have been found in various plant and animal sources. They play important roles in biological recognition events, such as cell-cell adhesion, and can also be involved in the immune response. Some lectins can agglutinate certain types of cells or precipitate glycoproteins, while others may have a more direct effect on cellular processes. In some cases, lectins from plants can cause adverse effects in humans if ingested, such as digestive discomfort or allergic reactions.

A "knockout" mouse is a genetically engineered mouse in which one or more genes have been deleted or "knocked out" using molecular biology techniques. This allows researchers to study the function of specific genes and their role in various biological processes, as well as potential associations with human diseases. The mice are generated by introducing targeted DNA modifications into embryonic stem cells, which are then used to create a live animal. Knockout mice have been widely used in biomedical research to investigate gene function, disease mechanisms, and potential therapeutic targets.

Sequence homology, amino acid, refers to the similarity in the order of amino acids in a protein or a portion of a protein between two or more species. This similarity can be used to infer evolutionary relationships and functional similarities between proteins. The higher the degree of sequence homology, the more likely it is that the proteins are related and have similar functions. Sequence homology can be determined through various methods such as pairwise alignment or multiple sequence alignment, which compare the sequences and calculate a score based on the number and type of matching amino acids.

Innate immunity, also known as non-specific immunity or natural immunity, is the inherent defense mechanism that provides immediate protection against potentially harmful pathogens (like bacteria, viruses, fungi, and parasites) without the need for prior exposure. This type of immunity is present from birth and does not adapt to specific threats over time.

Innate immune responses involve various mechanisms such as:

1. Physical barriers: Skin and mucous membranes prevent pathogens from entering the body.
2. Chemical barriers: Enzymes, stomach acid, and lysozyme in tears, saliva, and sweat help to destroy or inhibit the growth of microorganisms.
3. Cellular responses: Phagocytic cells (neutrophils, monocytes, macrophages) recognize and engulf foreign particles and pathogens, while natural killer (NK) cells target and eliminate virus-infected or cancerous cells.
4. Inflammatory response: When an infection occurs, the innate immune system triggers inflammation to increase blood flow, recruit immune cells, and remove damaged tissue.
5. Complement system: A group of proteins that work together to recognize and destroy pathogens directly or enhance phagocytosis by coating them with complement components (opsonization).

Innate immunity plays a crucial role in initiating the adaptive immune response, which is specific to particular pathogens and provides long-term protection through memory cells. Both innate and adaptive immunity work together to maintain overall immune homeostasis and protect the body from infections and diseases.

I apologize, but "sheep" is not a term that has a medical definition. It is a common animal with the scientific name Ovis aries. If you have any medical or health-related questions, I would be happy to try and help answer those for you.

Immunologic cytotoxicity refers to the damage or destruction of cells that occurs as a result of an immune response. This process involves the activation of immune cells, such as cytotoxic T cells and natural killer (NK) cells, which release toxic substances, such as perforins and granzymes, that can kill target cells.

In addition, antibodies produced by B cells can also contribute to immunologic cytotoxicity by binding to antigens on the surface of target cells and triggering complement-mediated lysis or antibody-dependent cellular cytotoxicity (ADCC) by activating immune effector cells.

Immunologic cytotoxicity plays an important role in the body's defense against viral infections, cancer cells, and other foreign substances. However, it can also contribute to tissue damage and autoimmune diseases if the immune system mistakenly targets healthy cells or tissues.

Macrophages are a type of white blood cell that are an essential part of the immune system. They are large, specialized cells that engulf and destroy foreign substances, such as bacteria, viruses, parasites, and fungi, as well as damaged or dead cells. Macrophages are found throughout the body, including in the bloodstream, lymph nodes, spleen, liver, lungs, and connective tissues. They play a critical role in inflammation, immune response, and tissue repair and remodeling.

Macrophages originate from monocytes, which are a type of white blood cell produced in the bone marrow. When monocytes enter the tissues, they differentiate into macrophages, which have a larger size and more specialized functions than monocytes. Macrophages can change their shape and move through tissues to reach sites of infection or injury. They also produce cytokines, chemokines, and other signaling molecules that help coordinate the immune response and recruit other immune cells to the site of infection or injury.

Macrophages have a variety of surface receptors that allow them to recognize and respond to different types of foreign substances and signals from other cells. They can engulf and digest foreign particles, bacteria, and viruses through a process called phagocytosis. Macrophages also play a role in presenting antigens to T cells, which are another type of immune cell that helps coordinate the immune response.

Overall, macrophages are crucial for maintaining tissue homeostasis, defending against infection, and promoting wound healing and tissue repair. Dysregulation of macrophage function has been implicated in a variety of diseases, including cancer, autoimmune disorders, and chronic inflammatory conditions.

An antigen-antibody reaction is a specific immune response that occurs when an antigen (a foreign substance, such as a protein or polysaccharide on the surface of a bacterium or virus) comes into contact with a corresponding antibody (a protective protein produced by the immune system in response to the antigen). The antigen and antibody bind together, forming an antigen-antibody complex. This interaction can neutralize the harmful effects of the antigen, mark it for destruction by other immune cells, or activate complement proteins to help eliminate the antigen from the body. Antigen-antibody reactions are a crucial part of the adaptive immune response and play a key role in the body's defense against infection and disease.

A dose-response relationship in immunology refers to the quantitative relationship between the dose or amount of an antigen (a substance that triggers an immune response) and the magnitude or strength of the resulting immune response. Generally, as the dose of an antigen increases, the intensity and/or duration of the immune response also increase, up to a certain point. This relationship helps in determining the optimal dosage for vaccines and immunotherapies, ensuring sufficient immune activation while minimizing potential adverse effects.

Species specificity is a term used in the field of biology, including medicine, to refer to the characteristic of a biological entity (such as a virus, bacterium, or other microorganism) that allows it to interact exclusively or preferentially with a particular species. This means that the biological entity has a strong affinity for, or is only able to infect, a specific host species.

For example, HIV is specifically adapted to infect human cells and does not typically infect other animal species. Similarly, some bacterial toxins are species-specific and can only affect certain types of animals or humans. This concept is important in understanding the transmission dynamics and host range of various pathogens, as well as in developing targeted therapies and vaccines.

Electrophoresis, polyacrylamide gel (EPG) is a laboratory technique used to separate and analyze complex mixtures of proteins or nucleic acids (DNA or RNA) based on their size and electrical charge. This technique utilizes a matrix made of cross-linked polyacrylamide, a type of gel, which provides a stable and uniform environment for the separation of molecules.

In this process:

1. The polyacrylamide gel is prepared by mixing acrylamide monomers with a cross-linking agent (bis-acrylamide) and a catalyst (ammonium persulfate) in the presence of a buffer solution.
2. The gel is then poured into a mold and allowed to polymerize, forming a solid matrix with uniform pore sizes that depend on the concentration of acrylamide used. Higher concentrations result in smaller pores, providing better resolution for separating smaller molecules.
3. Once the gel has set, it is placed in an electrophoresis apparatus containing a buffer solution. Samples containing the mixture of proteins or nucleic acids are loaded into wells on the top of the gel.
4. An electric field is applied across the gel, causing the negatively charged molecules to migrate towards the positive electrode (anode) while positively charged molecules move toward the negative electrode (cathode). The rate of migration depends on the size, charge, and shape of the molecules.
5. Smaller molecules move faster through the gel matrix and will migrate farther from the origin compared to larger molecules, resulting in separation based on size. Proteins and nucleic acids can be selectively stained after electrophoresis to visualize the separated bands.

EPG is widely used in various research fields, including molecular biology, genetics, proteomics, and forensic science, for applications such as protein characterization, DNA fragment analysis, cloning, mutation detection, and quality control of nucleic acid or protein samples.

Autoantibodies are defined as antibodies that are produced by the immune system and target the body's own cells, tissues, or organs. These antibodies mistakenly identify certain proteins or molecules in the body as foreign invaders and attack them, leading to an autoimmune response. Autoantibodies can be found in various autoimmune diseases such as rheumatoid arthritis, lupus, and thyroiditis. The presence of autoantibodies can also be used as a diagnostic marker for certain conditions.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

A binding site on an antibody refers to the specific region on the surface of the antibody molecule that can recognize and bind to a specific antigen. Antibodies are proteins produced by the immune system in response to the presence of foreign substances called antigens. They have two main functions: to neutralize the harmful effects of antigens and to help eliminate them from the body.

The binding site of an antibody is located at the tips of its Y-shaped structure, formed by the variable regions of the heavy and light chains of the antibody molecule. These regions contain unique amino acid sequences that determine the specificity of the antibody for a particular antigen. The binding site can recognize and bind to a specific epitope or region on the antigen, forming an antigen-antibody complex.

The binding between the antibody and antigen is highly specific and depends on non-covalent interactions such as hydrogen bonds, van der Waals forces, and electrostatic attractions. This interaction plays a crucial role in the immune response, as it allows the immune system to recognize and eliminate pathogens and other foreign substances from the body.

Animal disease models are specialized animals, typically rodents such as mice or rats, that have been genetically engineered or exposed to certain conditions to develop symptoms and physiological changes similar to those seen in human diseases. These models are used in medical research to study the pathophysiology of diseases, identify potential therapeutic targets, test drug efficacy and safety, and understand disease mechanisms.

The genetic modifications can include knockout or knock-in mutations, transgenic expression of specific genes, or RNA interference techniques. The animals may also be exposed to environmental factors such as chemicals, radiation, or infectious agents to induce the disease state.

Examples of animal disease models include:

1. Mouse models of cancer: Genetically engineered mice that develop various types of tumors, allowing researchers to study cancer initiation, progression, and metastasis.
2. Alzheimer's disease models: Transgenic mice expressing mutant human genes associated with Alzheimer's disease, which exhibit amyloid plaque formation and cognitive decline.
3. Diabetes models: Obese and diabetic mouse strains like the NOD (non-obese diabetic) or db/db mice, used to study the development of type 1 and type 2 diabetes, respectively.
4. Cardiovascular disease models: Atherosclerosis-prone mice, such as ApoE-deficient or LDLR-deficient mice, that develop plaque buildup in their arteries when fed a high-fat diet.
5. Inflammatory bowel disease models: Mice with genetic mutations affecting intestinal barrier function and immune response, such as IL-10 knockout or SAMP1/YitFc mice, which develop colitis.

Animal disease models are essential tools in preclinical research, but it is important to recognize their limitations. Differences between species can affect the translatability of results from animal studies to human patients. Therefore, researchers must carefully consider the choice of model and interpret findings cautiously when applying them to human diseases.

Glycoproteins are complex proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide backbone. These glycans are linked to the protein through asparagine residues (N-linked) or serine/threonine residues (O-linked). Glycoproteins play crucial roles in various biological processes, including cell recognition, cell-cell interactions, cell adhesion, and signal transduction. They are widely distributed in nature and can be found on the outer surface of cell membranes, in extracellular fluids, and as components of the extracellular matrix. The structure and composition of glycoproteins can vary significantly depending on their function and location within an organism.

A kidney glomerulus is a functional unit in the nephron of the kidney. It is a tuft of capillaries enclosed within a structure called Bowman's capsule, which filters waste and excess fluids from the blood. The glomerulus receives blood from an afferent arteriole and drains into an efferent arteriole.

The process of filtration in the glomerulus is called ultrafiltration, where the pressure within the glomerular capillaries drives plasma fluid and small molecules (such as ions, glucose, amino acids, and waste products) through the filtration membrane into the Bowman's space. Larger molecules, like proteins and blood cells, are retained in the blood due to their larger size. The filtrate then continues down the nephron for further processing, eventually forming urine.

Serum, in the context of clinical and medical laboratory science, refers to the fluid that is obtained after blood coagulation. It is the yellowish, straw-colored liquid fraction of whole blood that remains after the clotting factors have been removed. Serum contains various proteins, electrolytes, hormones, antibodies, antigens, and other substances, which can be analyzed to help diagnose and monitor a wide range of medical conditions. It is commonly used for various clinical tests such as chemistry panels, immunological assays, drug screening, and infectious disease testing.

Rosette formation is a term used in pathology and histology, which refers to the circular arrangement of cells or structures around a central point, creating a pattern that resembles a rose flower. This phenomenon can be observed in various tissues and diseases. For example, in the context of cancer, rosette formation may be seen in certain types of tumors, such as medulloblastomas or retinoblastomas, where cancer cells cluster around blood vessels or form distinctive arrangements that are characteristic of these malignancies. In some cases, rosette formation can provide valuable clues for the diagnosis and classification of neoplasms. However, it is essential to consider other histological features and clinical context when interpreting rosette formation in diagnostic pathology.

A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.

A peptide fragment is a short chain of amino acids that is derived from a larger peptide or protein through various biological or chemical processes. These fragments can result from the natural breakdown of proteins in the body during regular physiological processes, such as digestion, or they can be produced experimentally in a laboratory setting for research or therapeutic purposes.

Peptide fragments are often used in research to map the structure and function of larger peptides and proteins, as well as to study their interactions with other molecules. In some cases, peptide fragments may also have biological activity of their own and can be developed into drugs or diagnostic tools. For example, certain peptide fragments derived from hormones or neurotransmitters may bind to receptors in the body and mimic or block the effects of the full-length molecule.

Membrane glycoproteins are proteins that contain oligosaccharide chains (glycans) covalently attached to their polypeptide backbone. They are integral components of biological membranes, spanning the lipid bilayer and playing crucial roles in various cellular processes.

The glycosylation of these proteins occurs in the endoplasmic reticulum (ER) and Golgi apparatus during protein folding and trafficking. The attached glycans can vary in structure, length, and composition, which contributes to the diversity of membrane glycoproteins.

Membrane glycoproteins can be classified into two main types based on their orientation within the lipid bilayer:

1. Type I (N-linked): These glycoproteins have a single transmembrane domain and an extracellular N-terminus, where the oligosaccharides are predominantly attached via asparagine residues (Asn-X-Ser/Thr sequon).
2. Type II (C-linked): These glycoproteins possess two transmembrane domains and an intracellular C-terminus, with the oligosaccharides linked to tryptophan residues via a mannose moiety.

Membrane glycoproteins are involved in various cellular functions, such as:

* Cell adhesion and recognition
* Receptor-mediated signal transduction
* Enzymatic catalysis
* Transport of molecules across membranes
* Cell-cell communication
* Immunological responses

Some examples of membrane glycoproteins include cell surface receptors (e.g., growth factor receptors, cytokine receptors), adhesion molecules (e.g., integrins, cadherins), and transporters (e.g., ion channels, ABC transporters).

Messenger RNA (mRNA) is a type of RNA (ribonucleic acid) that carries genetic information copied from DNA in the form of a series of three-base code "words," each of which specifies a particular amino acid. This information is used by the cell's machinery to construct proteins, a process known as translation. After being transcribed from DNA, mRNA travels out of the nucleus to the ribosomes in the cytoplasm where protein synthesis occurs. Once the protein has been synthesized, the mRNA may be degraded and recycled. Post-transcriptional modifications can also occur to mRNA, such as alternative splicing and addition of a 5' cap and a poly(A) tail, which can affect its stability, localization, and translation efficiency.

Tertiary protein structure refers to the three-dimensional arrangement of all the elements (polypeptide chains) of a single protein molecule. It is the highest level of structural organization and results from interactions between various side chains (R groups) of the amino acids that make up the protein. These interactions, which include hydrogen bonds, ionic bonds, van der Waals forces, and disulfide bridges, give the protein its unique shape and stability, which in turn determines its function. The tertiary structure of a protein can be stabilized by various factors such as temperature, pH, and the presence of certain ions. Any changes in these factors can lead to denaturation, where the protein loses its tertiary structure and thus its function.

Membranoproliferative Glomerulonephritis (MPGN) is a type of glomerulonephritis, which is a group of kidney disorders characterized by inflammation and damage to the glomeruli, the tiny blood vessels in the kidneys responsible for filtering waste and excess fluids from the blood.

MPGN is specifically characterized by thickening of the glomerular basement membrane and proliferation (increased number) of cells in the mesangium, a region within the glomerulus. This condition can be primary or secondary to other diseases such as infections, autoimmune disorders, or monoclonal gammopathies.

MPGN is typically classified into three types based on the pattern of injury seen on electron microscopy: Type I, Type II (Dense Deposit Disease), and Type III. Each type has distinct clinical features, laboratory findings, and treatment approaches. Symptoms of MPGN may include hematuria (blood in urine), proteinuria (protein in urine), hypertension (high blood pressure), edema (swelling), and eventually progress to chronic kidney disease or end-stage renal disease if left untreated.

CD (cluster of differentiation) antigens are cell-surface proteins that are expressed on leukocytes (white blood cells) and can be used to identify and distinguish different subsets of these cells. They are important markers in the field of immunology and hematology, and are commonly used to diagnose and monitor various diseases, including cancer, autoimmune disorders, and infectious diseases.

CD antigens are designated by numbers, such as CD4, CD8, CD19, etc., which refer to specific proteins found on the surface of different types of leukocytes. For example, CD4 is a protein found on the surface of helper T cells, while CD8 is found on cytotoxic T cells.

CD antigens can be used as targets for immunotherapy, such as monoclonal antibody therapy, in which antibodies are designed to bind to specific CD antigens and trigger an immune response against cancer cells or infected cells. They can also be used as markers to monitor the effectiveness of treatments and to detect minimal residual disease (MRD) after treatment.

It's important to note that not all CD antigens are exclusive to leukocytes, some can be found on other cell types as well, and their expression can vary depending on the activation state or differentiation stage of the cells.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Antibody-Dependent Cell Cytotoxicity (ADCC) is a type of immune response in which the effector cells of the immune system, such as natural killer (NK) cells, cytotoxic T-cells or macrophages, recognize and destroy virus-infected or cancer cells that are coated with antibodies.

In this process, an antibody produced by B-cells binds specifically to an antigen on the surface of a target cell. The other end of the antibody then interacts with Fc receptors found on the surface of effector cells. This interaction triggers the effector cells to release cytotoxic substances, such as perforins and granzymes, which create pores in the target cell membrane and induce apoptosis (programmed cell death).

ADCC plays an important role in the immune defense against viral infections and cancer. It is also a mechanism of action for some monoclonal antibody therapies used in cancer treatment.

BALB/c is an inbred strain of laboratory mouse that is widely used in biomedical research. The strain was developed at the Institute of Cancer Research in London by Henry Baldwin and his colleagues in the 1920s, and it has since become one of the most commonly used inbred strains in the world.

BALB/c mice are characterized by their black coat color, which is determined by a recessive allele at the tyrosinase locus. They are also known for their docile and friendly temperament, making them easy to handle and work with in the laboratory.

One of the key features of BALB/c mice that makes them useful for research is their susceptibility to certain types of tumors and immune responses. For example, they are highly susceptible to developing mammary tumors, which can be induced by chemical carcinogens or viral infection. They also have a strong Th2-biased immune response, which makes them useful models for studying allergic diseases and asthma.

BALB/c mice are also commonly used in studies of genetics, neuroscience, behavior, and infectious diseases. Because they are an inbred strain, they have a uniform genetic background, which makes it easier to control for genetic factors in experiments. Additionally, because they have been bred in the laboratory for many generations, they are highly standardized and reproducible, making them ideal subjects for scientific research.

Gamma-globulins are a type of protein found in the blood serum, specifically a class of immunoglobulins (antibodies) known as IgG. They are the most abundant type of antibody and provide long-term defense against bacterial and viral infections. Gamma-globulins can also be referred to as "gamma globulin" or "gamma immune globulins."

These proteins are produced by B cells, a type of white blood cell, in response to an antigen (a foreign substance that triggers an immune response). IgG gamma-globulins have the ability to cross the placenta and provide passive immunity to the fetus. They can be measured through various medical tests such as serum protein electrophoresis (SPEP) or immunoelectrophoresis, which are used to diagnose and monitor conditions related to immune system disorders, such as multiple myeloma or primary immunodeficiency diseases.

In addition, gamma-globulins can be administered therapeutically in the form of intravenous immunoglobulin (IVIG) to provide passive immunity for patients with immunodeficiencies, autoimmune disorders, or infectious diseases.

Complement C3 Convertase, Classical Pathway is a protein complex that plays a crucial role in the activation of the complement system, which is a part of the immune system. The complement system helps to eliminate pathogens and damaged cells from the body.

The classical pathway is one of three pathways that can activate the complement system, with the other two being the lectin pathway and the alternative pathway. The classical pathway is initiated by the binding of antibodies to antigens on the surface of a pathogen or damaged cell. This binding event triggers a series of proteolytic cleavage reactions that result in the formation of the C3 Convertase complex.

The C3 Convertase complex, specifically the C4b2a form, is composed of two proteins: C4b and C2a. These proteins are derived from the cleavage of complement components C4 and C2 by an enzyme called C1 esterase. The C3 Convertase complex then cleaves complement component C3 into C3a and C3b fragments, which initiate further downstream reactions in the complement cascade.

The formation of the C3 Convertase complex is a critical step in the activation of the classical pathway, as it marks the point at which the complement system begins to amplify its response and recruit other immune cells to help eliminate the target pathogen or damaged cell. Dysregulation of the complement system, including abnormalities in the formation or function of the C3 Convertase complex, can contribute to a variety of diseases, including autoimmune disorders, inflammatory conditions, and infections.

Surface antigens are molecules found on the surface of cells that can be recognized by the immune system as being foreign or different from the host's own cells. Antigens are typically proteins or polysaccharides that are capable of stimulating an immune response, leading to the production of antibodies and activation of immune cells such as T-cells.

Surface antigens are important in the context of infectious diseases because they allow the immune system to identify and target infected cells for destruction. For example, viruses and bacteria often display surface antigens that are distinct from those found on host cells, allowing the immune system to recognize and attack them. In some cases, these surface antigens can also be used as targets for vaccines or other immunotherapies.

In addition to their role in infectious diseases, surface antigens are also important in the context of cancer. Tumor cells often display abnormal surface antigens that differ from those found on normal cells, allowing the immune system to potentially recognize and attack them. However, tumors can also develop mechanisms to evade the immune system, making it difficult to mount an effective response.

Overall, understanding the properties and behavior of surface antigens is crucial for developing effective immunotherapies and vaccines against infectious diseases and cancer.

Cricetinae is a subfamily of rodents that includes hamsters, gerbils, and relatives. These small mammals are characterized by having short limbs, compact bodies, and cheek pouches for storing food. They are native to various parts of the world, particularly in Europe, Asia, and Africa. Some species are popular pets due to their small size, easy care, and friendly nature. In a medical context, understanding the biology and behavior of Cricetinae species can be important for individuals who keep them as pets or for researchers studying their physiology.

Surface Plasmon Resonance (SPR) is a physical phenomenon that occurs at the interface between a metal and a dielectric material, when electromagnetic radiation (usually light) is shone on it. It involves the collective oscillation of free electrons in the metal, known as surface plasmons, which are excited by the incident light. The resonance condition is met when the momentum and energy of the photons match those of the surface plasmons, leading to a strong absorption of light and an evanescent wave that extends into the dielectric material.

In the context of medical diagnostics and research, SPR is often used as a sensitive and label-free detection technique for biomolecular interactions. By immobilizing one binding partner (e.g., a receptor or antibody) onto the metal surface and flowing the other partner (e.g., a ligand or antigen) over it, changes in the refractive index at the interface can be measured in real-time as the plasmons are disturbed by the presence of bound molecules. This allows for the quantification of binding affinities, kinetics, and specificity with high sensitivity and selectivity.

Flow cytometry is a medical and research technique used to measure physical and chemical characteristics of cells or particles, one cell at a time, as they flow in a fluid stream through a beam of light. The properties measured include:

* Cell size (light scatter)
* Cell internal complexity (granularity, also light scatter)
* Presence or absence of specific proteins or other molecules on the cell surface or inside the cell (using fluorescent antibodies or other fluorescent probes)

The technique is widely used in cell counting, cell sorting, protein engineering, biomarker discovery and monitoring disease progression, particularly in hematology, immunology, and cancer research.

Immune evasion is a term used in immunology to describe the various strategies employed by pathogens (such as viruses, bacteria, parasites) to avoid or subvert the host's immune system. This can include mechanisms that allow the pathogen to directly inhibit or escape the actions of immune cells, like T cells and neutrophils, or to prevent the detection of their presence by masking themselves from the immune system.

For example, some viruses may change their surface proteins to avoid recognition by antibodies, while others may block the presentation of their antigens to T cells. Similarly, some bacteria can produce enzymes that degrade or modify components of the immune system, allowing them to evade detection and destruction.

Immune evasion is a major challenge in the development of effective vaccines and therapies for infectious diseases, as it allows pathogens to persist and cause chronic infections. Understanding the mechanisms of immune evasion can help researchers develop strategies to overcome these challenges and improve outcomes for patients.

Immunoglobulin Fc fragments are the crystallizable fragment of an antibody that is responsible for effector functions such as engagement with Fc receptors on immune cells, activation of the complement system, and neutralization of toxins. The Fc region is located at the tail end of the Y-shaped immunoglobulin molecule, and it is made up of constant regions of the heavy chains of the antibody.

When an antibody binds to its target antigen, the Fc region can interact with other proteins in the immune system, leading to a variety of responses such as phagocytosis, antibody-dependent cellular cytotoxicity (ADCC), and complement activation. These effector functions help to eliminate pathogens and infected cells from the body.

Immunoglobulin Fc fragments can be produced artificially through enzymatic digestion of intact antibodies, resulting in a fragment that retains the ability to interact with Fc receptors and other proteins involved in immune responses. These fragments have potential therapeutic applications in a variety of diseases, including autoimmune disorders, inflammatory conditions, and cancer.

Membrane proteins are a type of protein that are embedded in the lipid bilayer of biological membranes, such as the plasma membrane of cells or the inner membrane of mitochondria. These proteins play crucial roles in various cellular processes, including:

1. Cell-cell recognition and signaling
2. Transport of molecules across the membrane (selective permeability)
3. Enzymatic reactions at the membrane surface
4. Energy transduction and conversion
5. Mechanosensation and signal transduction

Membrane proteins can be classified into two main categories: integral membrane proteins, which are permanently associated with the lipid bilayer, and peripheral membrane proteins, which are temporarily or loosely attached to the membrane surface. Integral membrane proteins can further be divided into three subcategories based on their topology:

1. Transmembrane proteins, which span the entire width of the lipid bilayer with one or more alpha-helices or beta-barrels.
2. Lipid-anchored proteins, which are covalently attached to lipids in the membrane via a glycosylphosphatidylinositol (GPI) anchor or other lipid modifications.
3. Monotopic proteins, which are partially embedded in the membrane and have one or more domains exposed to either side of the bilayer.

Membrane proteins are essential for maintaining cellular homeostasis and are targets for various therapeutic interventions, including drug development and gene therapy. However, their structural complexity and hydrophobicity make them challenging to study using traditional biochemical methods, requiring specialized techniques such as X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and single-particle cryo-electron microscopy (cryo-EM).

Carrier proteins, also known as transport proteins, are a type of protein that facilitates the movement of molecules across cell membranes. They are responsible for the selective and active transport of ions, sugars, amino acids, and other molecules from one side of the membrane to the other, against their concentration gradient. This process requires energy, usually in the form of ATP (adenosine triphosphate).

Carrier proteins have a specific binding site for the molecule they transport, and undergo conformational changes upon binding, which allows them to move the molecule across the membrane. Once the molecule has been transported, the carrier protein returns to its original conformation, ready to bind and transport another molecule.

Carrier proteins play a crucial role in maintaining the balance of ions and other molecules inside and outside of cells, and are essential for many physiological processes, including nerve impulse transmission, muscle contraction, and nutrient uptake.

The Arthus reaction is a type of localized immune complex-mediated hypersensitivity reaction (type III hypersensitivity). It is named after the French scientist Nicolas Maurice Arthus who first described it in 1903. The reaction occurs when an antigen is injected into the skin or tissues of a sensitized individual, leading to the formation of immune complexes composed of antigens and antibodies (usually IgG). These immune complexes deposit in the small blood vessels, causing complement activation, recruitment of inflammatory cells, and release of mediators that result in tissue damage.

Clinically, an Arthus reaction is characterized by localized signs of inflammation, such as redness, swelling, pain, and warmth at the site of antigen injection. In severe cases, it can lead to necrosis and sloughing of the skin. The Arthus reaction typically occurs within 2-8 hours after antigen exposure and is distinct from immediate hypersensitivity reactions (type I), which occur within minutes of antigen exposure.

The Arthus reaction is often seen in laboratory animals used for antibody production, where repeated injections of antigens can lead to sensitization and subsequent Arthus reactions. In humans, it can occur as a complication of immunizations or diagnostic tests that involve the injection of foreign proteins or drugs. To prevent Arthus reactions, healthcare providers may perform skin testing before administering certain medications or vaccines to assess for preexisting sensitization.

In genetics, sequence alignment is the process of arranging two or more DNA, RNA, or protein sequences to identify regions of similarity or homology between them. This is often done using computational methods to compare the nucleotide or amino acid sequences and identify matching patterns, which can provide insight into evolutionary relationships, functional domains, or potential genetic disorders. The alignment process typically involves adjusting gaps and mismatches in the sequences to maximize the similarity between them, resulting in an aligned sequence that can be visually represented and analyzed.

Antibody specificity refers to the ability of an antibody to bind to a specific epitope or antigenic determinant on an antigen. Each antibody has a unique structure that allows it to recognize and bind to a specific region of an antigen, typically a small portion of the antigen's surface made up of amino acids or sugar residues. This highly specific binding is mediated by the variable regions of the antibody's heavy and light chains, which form a pocket that recognizes and binds to the epitope.

The specificity of an antibody is determined by its unique complementarity-determining regions (CDRs), which are loops of amino acids located in the variable domains of both the heavy and light chains. The CDRs form a binding site that recognizes and interacts with the epitope on the antigen. The precise fit between the antibody's binding site and the epitope is critical for specificity, as even small changes in the structure of either can prevent binding.

Antibody specificity is important in immune responses because it allows the immune system to distinguish between self and non-self antigens. This helps to prevent autoimmune reactions where the immune system attacks the body's own cells and tissues. Antibody specificity also plays a crucial role in diagnostic tests, such as ELISA assays, where antibodies are used to detect the presence of specific antigens in biological samples.

Molecular weight, also known as molecular mass, is the mass of a molecule. It is expressed in units of atomic mass units (amu) or daltons (Da). Molecular weight is calculated by adding up the atomic weights of each atom in a molecule. It is a useful property in chemistry and biology, as it can be used to determine the concentration of a substance in a solution, or to calculate the amount of a substance that will react with another in a chemical reaction.

A plasmid is a small, circular, double-stranded DNA molecule that is separate from the chromosomal DNA of a bacterium or other organism. Plasmids are typically not essential for the survival of the organism, but they can confer beneficial traits such as antibiotic resistance or the ability to degrade certain types of pollutants.

Plasmids are capable of replicating independently of the chromosomal DNA and can be transferred between bacteria through a process called conjugation. They often contain genes that provide resistance to antibiotics, heavy metals, and other environmental stressors. Plasmids have also been engineered for use in molecular biology as cloning vectors, allowing scientists to replicate and manipulate specific DNA sequences.

Plasmids are important tools in genetic engineering and biotechnology because they can be easily manipulated and transferred between organisms. They have been used to produce vaccines, diagnostic tests, and genetically modified organisms (GMOs) for various applications, including agriculture, medicine, and industry.

A bacterial gene is a segment of DNA (or RNA in some viruses) that contains the genetic information necessary for the synthesis of a functional bacterial protein or RNA molecule. These genes are responsible for encoding various characteristics and functions of bacteria such as metabolism, reproduction, and resistance to antibiotics. They can be transmitted between bacteria through horizontal gene transfer mechanisms like conjugation, transformation, and transduction. Bacterial genes are often organized into operons, which are clusters of genes that are transcribed together as a single mRNA molecule.

It's important to note that the term "bacterial gene" is used to describe genetic elements found in bacteria, but not all genetic elements in bacteria are considered genes. For example, some DNA sequences may not encode functional products and are therefore not considered genes. Additionally, some bacterial genes may be plasmid-borne or phage-borne, rather than being located on the bacterial chromosome.

B-lymphocytes, also known as B-cells, are a type of white blood cell that plays a key role in the immune system's response to infection. They are responsible for producing antibodies, which are proteins that help to neutralize or destroy pathogens such as bacteria and viruses.

When a B-lymphocyte encounters a pathogen, it becomes activated and begins to divide and differentiate into plasma cells, which produce and secrete large amounts of antibodies specific to the antigens on the surface of the pathogen. These antibodies bind to the pathogen, marking it for destruction by other immune cells such as neutrophils and macrophages.

B-lymphocytes also have a role in presenting antigens to T-lymphocytes, another type of white blood cell involved in the immune response. This helps to stimulate the activation and proliferation of T-lymphocytes, which can then go on to destroy infected cells or help to coordinate the overall immune response.

Overall, B-lymphocytes are an essential part of the adaptive immune system, providing long-lasting immunity to previously encountered pathogens and helping to protect against future infections.

Monocytes are a type of white blood cell that are part of the immune system. They are large cells with a round or oval shape and a nucleus that is typically indented or horseshoe-shaped. Monocytes are produced in the bone marrow and then circulate in the bloodstream, where they can differentiate into other types of immune cells such as macrophages and dendritic cells.

Monocytes play an important role in the body's defense against infection and tissue damage. They are able to engulf and digest foreign particles, microorganisms, and dead or damaged cells, which helps to clear them from the body. Monocytes also produce cytokines, which are signaling molecules that help to coordinate the immune response.

Elevated levels of monocytes in the bloodstream can be a sign of an ongoing infection, inflammation, or other medical conditions such as cancer or autoimmune disorders.

Nephritis is a medical term that refers to inflammation of the kidneys, specifically affecting the glomeruli - the tiny filtering units inside the kidneys. The condition can cause damage to the glomeruli, leading to impaired kidney function and the leakage of protein and blood into the urine.

Nephritis can result from a variety of causes, including infections, autoimmune disorders, and exposure to certain medications or toxins. Depending on the severity and underlying cause, nephritis may be treated with medications, dietary modifications, or other therapies aimed at reducing inflammation and preserving kidney function. In severe cases, hospitalization and more intensive treatments may be necessary.

"Saccharomyces cerevisiae" is not typically considered a medical term, but it is a scientific name used in the field of microbiology. It refers to a species of yeast that is commonly used in various industrial processes, such as baking and brewing. It's also widely used in scientific research due to its genetic tractability and eukaryotic cellular organization.

However, it does have some relevance to medical fields like medicine and nutrition. For example, certain strains of S. cerevisiae are used as probiotics, which can provide health benefits when consumed. They may help support gut health, enhance the immune system, and even assist in the digestion of certain nutrients.

In summary, "Saccharomyces cerevisiae" is a species of yeast with various industrial and potential medical applications.

Edetic acid, also known as ethylenediaminetetraacetic acid (EDTA), is not a medical term per se, but a chemical compound with various applications in medicine. EDTA is a synthetic amino acid that acts as a chelating agent, which means it can bind to metallic ions and form stable complexes.

In medicine, EDTA is primarily used in the treatment of heavy metal poisoning, such as lead or mercury toxicity. It works by binding to the toxic metal ions in the body, forming a stable compound that can be excreted through urine. This helps reduce the levels of harmful metals in the body and alleviate their toxic effects.

EDTA is also used in some diagnostic tests, such as the determination of calcium levels in blood. Additionally, it has been explored as a potential therapy for conditions like atherosclerosis and Alzheimer's disease, although its efficacy in these areas remains controversial and unproven.

It is important to note that EDTA should only be administered under medical supervision due to its potential side effects and the need for careful monitoring of its use.

IgG receptors, also known as Fcγ receptors (Fc gamma receptors), are specialized protein molecules found on the surface of various immune cells, such as neutrophils, monocytes, macrophages, and some lymphocytes. These receptors recognize and bind to the Fc region of IgG antibodies, one of the five classes of immunoglobulins in the human body.

IgG receptors play a crucial role in immune responses by mediating different effector functions, including:

1. Antibody-dependent cellular cytotoxicity (ADCC): IgG receptors on natural killer (NK) cells and other immune cells bind to IgG antibodies coated on the surface of virus-infected or cancer cells, leading to their destruction.
2. Phagocytosis: When IgG antibodies tag pathogens or foreign particles, phagocytes like neutrophils and macrophages recognize and bind to these immune complexes via IgG receptors, facilitating the engulfment and removal of the targeted particles.
3. Antigen presentation: IgG receptors on antigen-presenting cells (APCs) can internalize immune complexes, process the antigens, and present them to T cells, thereby initiating adaptive immune responses.
4. Inflammatory response regulation: IgG receptors can modulate inflammation by activating or inhibiting downstream signaling pathways in immune cells, depending on the specific type of Fcγ receptor and its activation state.

There are several types of IgG receptors (FcγRI, FcγRII, FcγRIII, and FcγRIV) with varying affinities for different subclasses of IgG antibodies (IgG1, IgG2, IgG3, and IgG4). The distinct functions and expression patterns of these receptors contribute to the complexity and fine-tuning of immune responses in the human body.

Inflammation is a complex biological response of tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. It is characterized by the following signs: rubor (redness), tumor (swelling), calor (heat), dolor (pain), and functio laesa (loss of function). The process involves the activation of the immune system, recruitment of white blood cells, and release of inflammatory mediators, which contribute to the elimination of the injurious stimuli and initiation of the healing process. However, uncontrolled or chronic inflammation can also lead to tissue damage and diseases.

Bacterial polysaccharides are complex carbohydrates that consist of long chains of sugar molecules (monosaccharides) linked together by glycosidic bonds. They are produced and used by bacteria for various purposes such as:

1. Structural components: Bacterial polysaccharides, such as peptidoglycan and lipopolysaccharide (LPS), play a crucial role in maintaining the structural integrity of bacterial cells. Peptidoglycan is a major component of the bacterial cell wall, while LPS forms the outer layer of the outer membrane in gram-negative bacteria.
2. Nutrient storage: Some bacteria synthesize and store polysaccharides as an energy reserve, similar to how plants store starch. These polysaccharides can be broken down and utilized by the bacterium when needed.
3. Virulence factors: Bacterial polysaccharides can also function as virulence factors, contributing to the pathogenesis of bacterial infections. For example, certain bacteria produce capsular polysaccharides (CPS) that surround and protect the bacterial cells from host immune defenses, allowing them to evade phagocytosis and persist within the host.
4. Adhesins: Some polysaccharides act as adhesins, facilitating the attachment of bacteria to surfaces or host cells. This is important for biofilm formation, which helps bacteria resist environmental stresses and antibiotic treatments.
5. Antigenic properties: Bacterial polysaccharides can be highly antigenic, eliciting an immune response in the host. The antigenicity of these molecules can vary between different bacterial species or even strains within a species, making them useful as targets for vaccines and diagnostic tests.

In summary, bacterial polysaccharides are complex carbohydrates that serve various functions in bacteria, including structural support, nutrient storage, virulence factor production, adhesion, and antigenicity.

Angioedema is a medical condition characterized by rapid swelling of the skin, mucous membranes, and submucosal tissues. The swelling typically occurs in the face, lips, tongue, larynx, and extremities, and can also affect the gastrointestinal tract. Angioedema can be caused by a variety of factors, including allergic reactions, hereditary genetic mutations, and certain medications.

In medical terms, angioedema is defined as a self-limiting episode of localized edema in the deep dermis, subcutaneous tissue, or mucous membranes, characterized by well-circumscribed, nonpitting, nondependent swelling. The swelling can occur suddenly and may persist for up to 72 hours. In severe cases, angioedema can cause airway obstruction and be life-threatening if not treated promptly.

Angioedema can be classified into two main types: allergic or non-allergic. Allergic angioedema is caused by an immune response to an allergen, such as food, medication, or insect venom. Non-allergic angioedema can be further divided into several subtypes, including hereditary angioedema (HA), acquired angioedema (AAE), and drug-induced angioedema.

Hereditary angioedema is a rare genetic disorder caused by mutations in the C1 inhibitor gene, leading to uncontrolled activation of the complement system and increased production of bradykinin, a potent vasodilator. Acquired angioedema is similar to hereditary angioedema but occurs later in life and is associated with underlying medical conditions such as lymphoproliferative disorders or autoimmune diseases. Drug-induced angioedema can be caused by a variety of medications, including ACE inhibitors, angiotensin receptor blockers (ARBs), and nonsteroidal anti-inflammatory drugs (NSAIDs).

The diagnosis of angioedema is typically based on clinical presentation, medical history, and laboratory tests. Treatment depends on the underlying cause of the condition but may include antihistamines, corticosteroids, epinephrine, and medications that target the complement system or bradykinin pathway. In severe cases, hospitalization and intensive care may be necessary to manage airway obstruction and other complications.

Bacterial outer membrane proteins (OMPs) are a type of protein found in the outer membrane of gram-negative bacteria. The outer membrane is a unique characteristic of gram-negative bacteria, and it serves as a barrier that helps protect the bacterium from hostile environments. OMPs play a crucial role in maintaining the structural integrity and selective permeability of the outer membrane. They are involved in various functions such as nutrient uptake, transport, adhesion, and virulence factor secretion.

OMPs are typically composed of beta-barrel structures that span the bacterial outer membrane. These proteins can be classified into several groups based on their size, function, and structure. Some of the well-known OMP families include porins, autotransporters, and two-partner secretion systems.

Porins are the most abundant type of OMPs and form water-filled channels that allow the passive diffusion of small molecules, ions, and nutrients across the outer membrane. Autotransporters are a diverse group of OMPs that play a role in bacterial pathogenesis by secreting virulence factors or acting as adhesins. Two-partner secretion systems involve the cooperation between two proteins to transport effector molecules across the outer membrane.

Understanding the structure and function of bacterial OMPs is essential for developing new antibiotics and therapies that target gram-negative bacteria, which are often resistant to conventional treatments.

Lipopolysaccharides (LPS) are large molecules found in the outer membrane of Gram-negative bacteria. They consist of a hydrophilic polysaccharide called the O-antigen, a core oligosaccharide, and a lipid portion known as Lipid A. The Lipid A component is responsible for the endotoxic activity of LPS, which can trigger a powerful immune response in animals, including humans. This response can lead to symptoms such as fever, inflammation, and septic shock, especially when large amounts of LPS are introduced into the bloodstream.

The spleen is an organ in the upper left side of the abdomen, next to the stomach and behind the ribs. It plays multiple supporting roles in the body:

1. It fights infection by acting as a filter for the blood. Old red blood cells are recycled in the spleen, and platelets and white blood cells are stored there.
2. The spleen also helps to control the amount of blood in the body by removing excess red blood cells and storing platelets.
3. It has an important role in immune function, producing antibodies and removing microorganisms and damaged red blood cells from the bloodstream.

The spleen can be removed without causing any significant problems, as other organs take over its functions. This is known as a splenectomy and may be necessary if the spleen is damaged or diseased.

Deoxyribonucleic acid (DNA) is the genetic material present in the cells of organisms where it is responsible for the storage and transmission of hereditary information. DNA is a long molecule that consists of two strands coiled together to form a double helix. Each strand is made up of a series of four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - that are linked together by phosphate and sugar groups. The sequence of these bases along the length of the molecule encodes genetic information, with A always pairing with T and C always pairing with G. This base-pairing allows for the replication and transcription of DNA, which are essential processes in the functioning and reproduction of all living organisms.

Fc receptors (FcRs) are specialized proteins found on the surface of various immune cells, including neutrophils, monocytes, macrophages, eosinophils, basophils, mast cells, and B lymphocytes. They play a crucial role in the immune response by recognizing and binding to the Fc region of antibodies (IgG, IgA, and IgE) after they have interacted with their specific antigens.

FcRs can be classified into several types based on the class of antibody they bind:

1. FcγRs - bind to the Fc region of IgG antibodies
2. FcαRs - bind to the Fc region of IgA antibodies
3. FcεRs - bind to the Fc region of IgE antibodies

The binding of antibodies to Fc receptors triggers various cellular responses, such as phagocytosis, degranulation, and antibody-dependent cellular cytotoxicity (ADCC), which contribute to the elimination of pathogens, immune complexes, and other foreign substances. Dysregulation of Fc receptor function has been implicated in several diseases, including autoimmune disorders and allergies.

A cell membrane, also known as the plasma membrane, is a thin semi-permeable phospholipid bilayer that surrounds all cells in animals, plants, and microorganisms. It functions as a barrier to control the movement of substances in and out of the cell, allowing necessary molecules such as nutrients, oxygen, and signaling molecules to enter while keeping out harmful substances and waste products. The cell membrane is composed mainly of phospholipids, which have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails. This unique structure allows the membrane to be flexible and fluid, yet selectively permeable. Additionally, various proteins are embedded in the membrane that serve as channels, pumps, receptors, and enzymes, contributing to the cell's overall functionality and communication with its environment.

Antibody formation, also known as humoral immune response, is the process by which the immune system produces proteins called antibodies in response to the presence of a foreign substance (antigen) in the body. This process involves several steps:

1. Recognition: The antigen is recognized and bound by a type of white blood cell called a B lymphocyte or B cell, which then becomes activated.
2. Differentiation: The activated B cell undergoes differentiation to become a plasma cell, which is a type of cell that produces and secretes large amounts of antibodies.
3. Antibody production: The plasma cells produce and release antibodies, which are proteins made up of four polypeptide chains (two heavy chains and two light chains) arranged in a Y-shape. Each antibody has two binding sites that can recognize and bind to specific regions on the antigen called epitopes.
4. Neutralization or elimination: The antibodies bind to the antigens, neutralizing them or marking them for destruction by other immune cells. This helps to prevent the spread of infection and protect the body from harmful substances.

Antibody formation is an important part of the adaptive immune response, which allows the body to specifically recognize and respond to a wide variety of pathogens and foreign substances.

Molecular models are three-dimensional representations of molecular structures that are used in the field of molecular biology and chemistry to visualize and understand the spatial arrangement of atoms and bonds within a molecule. These models can be physical or computer-generated and allow researchers to study the shape, size, and behavior of molecules, which is crucial for understanding their function and interactions with other molecules.

Physical molecular models are often made up of balls (representing atoms) connected by rods or sticks (representing bonds). These models can be constructed manually using materials such as plastic or wooden balls and rods, or they can be created using 3D printing technology.

Computer-generated molecular models, on the other hand, are created using specialized software that allows researchers to visualize and manipulate molecular structures in three dimensions. These models can be used to simulate molecular interactions, predict molecular behavior, and design new drugs or chemicals with specific properties. Overall, molecular models play a critical role in advancing our understanding of molecular structures and their functions.

Leukocytes, also known as white blood cells (WBCs), are a crucial component of the human immune system. They are responsible for protecting the body against infections and foreign substances. Leukocytes are produced in the bone marrow and circulate throughout the body in the bloodstream and lymphatic system.

There are several types of leukocytes, including:

1. Neutrophils - These are the most abundant type of leukocyte and are primarily responsible for fighting bacterial infections. They contain enzymes that can destroy bacteria.
2. Lymphocytes - These are responsible for producing antibodies and destroying virus-infected cells, as well as cancer cells. There are two main types of lymphocytes: B-lymphocytes and T-lymphocytes.
3. Monocytes - These are the largest type of leukocyte and help to break down and remove dead or damaged tissues, as well as microorganisms.
4. Eosinophils - These play a role in fighting parasitic infections and are also involved in allergic reactions and inflammation.
5. Basophils - These release histamine and other chemicals that cause inflammation in response to allergens or irritants.

An abnormal increase or decrease in the number of leukocytes can indicate an underlying medical condition, such as an infection, inflammation, or a blood disorder.

Antibodies, viral are proteins produced by the immune system in response to an infection with a virus. These antibodies are capable of recognizing and binding to specific antigens on the surface of the virus, which helps to neutralize or destroy the virus and prevent its replication. Once produced, these antibodies can provide immunity against future infections with the same virus.

Viral antibodies are typically composed of four polypeptide chains - two heavy chains and two light chains - that are held together by disulfide bonds. The binding site for the antigen is located at the tip of the Y-shaped structure, formed by the variable regions of the heavy and light chains.

There are five classes of antibodies in humans: IgA, IgD, IgE, IgG, and IgM. Each class has a different function and is distributed differently throughout the body. For example, IgG is the most common type of antibody found in the bloodstream and provides long-term immunity against viruses, while IgA is found primarily in mucous membranes and helps to protect against respiratory and gastrointestinal infections.

In addition to their role in the immune response, viral antibodies can also be used as diagnostic tools to detect the presence of a specific virus in a patient's blood or other bodily fluids.

Bacterial antigens are substances found on the surface or produced by bacteria that can stimulate an immune response in a host organism. These antigens can be proteins, polysaccharides, teichoic acids, lipopolysaccharides, or other molecules that are recognized as foreign by the host's immune system.

When a bacterial antigen is encountered by the host's immune system, it triggers a series of responses aimed at eliminating the bacteria and preventing infection. The host's immune system recognizes the antigen as foreign through the use of specialized receptors called pattern recognition receptors (PRRs), which are found on various immune cells such as macrophages, dendritic cells, and neutrophils.

Once a bacterial antigen is recognized by the host's immune system, it can stimulate both the innate and adaptive immune responses. The innate immune response involves the activation of inflammatory pathways, the recruitment of immune cells to the site of infection, and the production of antimicrobial peptides.

The adaptive immune response, on the other hand, involves the activation of T cells and B cells, which are specific to the bacterial antigen. These cells can recognize and remember the antigen, allowing for a more rapid and effective response upon subsequent exposures.

Bacterial antigens are important in the development of vaccines, as they can be used to stimulate an immune response without causing disease. By identifying specific bacterial antigens that are associated with virulence or pathogenicity, researchers can develop vaccines that target these antigens and provide protection against infection.

Neutralization tests are a type of laboratory assay used in microbiology and immunology to measure the ability of a substance, such as an antibody or antitoxin, to neutralize the activity of a toxin or infectious agent. In these tests, the substance to be tested is mixed with a known quantity of the toxin or infectious agent, and the mixture is then incubated under controlled conditions. After incubation, the mixture is tested for residual toxicity or infectivity using a variety of methods, such as cell culture assays, animal models, or biochemical assays.

The neutralization titer is then calculated based on the highest dilution of the test substance that completely neutralizes the toxin or infectious agent. Neutralization tests are commonly used in the diagnosis and evaluation of immune responses to vaccines, as well as in the detection and quantification of toxins and other harmful substances.

Examples of neutralization tests include the serum neutralization test for measles antibodies, the plaque reduction neutralization test (PRNT) for dengue virus antibodies, and the cytotoxicity neutralization assay for botulinum neurotoxins.

Western blotting is a laboratory technique used in molecular biology to detect and quantify specific proteins in a mixture of many different proteins. This technique is commonly used to confirm the expression of a protein of interest, determine its size, and investigate its post-translational modifications. The name "Western" blotting distinguishes this technique from Southern blotting (for DNA) and Northern blotting (for RNA).

The Western blotting procedure involves several steps:

1. Protein extraction: The sample containing the proteins of interest is first extracted, often by breaking open cells or tissues and using a buffer to extract the proteins.
2. Separation of proteins by electrophoresis: The extracted proteins are then separated based on their size by loading them onto a polyacrylamide gel and running an electric current through the gel (a process called sodium dodecyl sulfate-polyacrylamide gel electrophoresis or SDS-PAGE). This separates the proteins according to their molecular weight, with smaller proteins migrating faster than larger ones.
3. Transfer of proteins to a membrane: After separation, the proteins are transferred from the gel onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric current in a process called blotting. This creates a replica of the protein pattern on the gel but now immobilized on the membrane for further analysis.
4. Blocking: The membrane is then blocked with a blocking agent, such as non-fat dry milk or bovine serum albumin (BSA), to prevent non-specific binding of antibodies in subsequent steps.
5. Primary antibody incubation: A primary antibody that specifically recognizes the protein of interest is added and allowed to bind to its target protein on the membrane. This step may be performed at room temperature or 4°C overnight, depending on the antibody's properties.
6. Washing: The membrane is washed with a buffer to remove unbound primary antibodies.
7. Secondary antibody incubation: A secondary antibody that recognizes the primary antibody (often coupled to an enzyme or fluorophore) is added and allowed to bind to the primary antibody. This step may involve using a horseradish peroxidase (HRP)-conjugated or alkaline phosphatase (AP)-conjugated secondary antibody, depending on the detection method used later.
8. Washing: The membrane is washed again to remove unbound secondary antibodies.
9. Detection: A detection reagent is added to visualize the protein of interest by detecting the signal generated from the enzyme-conjugated or fluorophore-conjugated secondary antibody. This can be done using chemiluminescent, colorimetric, or fluorescent methods.
10. Analysis: The resulting image is analyzed to determine the presence and quantity of the protein of interest in the sample.

Western blotting is a powerful technique for identifying and quantifying specific proteins within complex mixtures. It can be used to study protein expression, post-translational modifications, protein-protein interactions, and more. However, it requires careful optimization and validation to ensure accurate and reproducible results.

T-lymphocytes, also known as T-cells, are a type of white blood cell that plays a key role in the adaptive immune system's response to infection. They are produced in the bone marrow and mature in the thymus gland. There are several different types of T-cells, including CD4+ helper T-cells, CD8+ cytotoxic T-cells, and regulatory T-cells (Tregs).

CD4+ helper T-cells assist in activating other immune cells, such as B-lymphocytes and macrophages. They also produce cytokines, which are signaling molecules that help coordinate the immune response. CD8+ cytotoxic T-cells directly kill infected cells by releasing toxic substances. Regulatory T-cells help maintain immune tolerance and prevent autoimmune diseases by suppressing the activity of other immune cells.

T-lymphocytes are important in the immune response to viral infections, cancer, and other diseases. Dysfunction or depletion of T-cells can lead to immunodeficiency and increased susceptibility to infections. On the other hand, an overactive T-cell response can contribute to autoimmune diseases and chronic inflammation.

An antigen is a substance (usually a protein) that is recognized as foreign by the immune system and stimulates an immune response, leading to the production of antibodies or activation of T-cells. Antigens can be derived from various sources, including bacteria, viruses, fungi, parasites, and tumor cells. They can also come from non-living substances such as pollen, dust mites, or chemicals.

Antigens contain epitopes, which are specific regions on the antigen molecule that are recognized by the immune system. The immune system's response to an antigen depends on several factors, including the type of antigen, its size, and its location in the body.

In general, antigens can be classified into two main categories:

1. T-dependent antigens: These require the help of T-cells to stimulate an immune response. They are typically larger, more complex molecules that contain multiple epitopes capable of binding to both MHC class II molecules on antigen-presenting cells and T-cell receptors on CD4+ T-cells.
2. T-independent antigens: These do not require the help of T-cells to stimulate an immune response. They are usually smaller, simpler molecules that contain repetitive epitopes capable of cross-linking B-cell receptors and activating them directly.

Understanding antigens and their properties is crucial for developing vaccines, diagnostic tests, and immunotherapies.

I'm sorry for any confusion, but "snakes" is not a medical term. It refers to a group of legless reptiles that can be found on every continent except Antarctica. If you have any questions about snakes in a different context, please provide more information and I'll do my best to help!

Electron microscopy (EM) is a type of microscopy that uses a beam of electrons to create an image of the sample being examined, resulting in much higher magnification and resolution than light microscopy. There are several types of electron microscopy, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), and reflection electron microscopy (REM).

In TEM, a beam of electrons is transmitted through a thin slice of the sample, and the electrons that pass through the sample are focused to form an image. This technique can provide detailed information about the internal structure of cells, viruses, and other biological specimens, as well as the composition and structure of materials at the atomic level.

In SEM, a beam of electrons is scanned across the surface of the sample, and the electrons that are scattered back from the surface are detected to create an image. This technique can provide information about the topography and composition of surfaces, as well as the structure of materials at the microscopic level.

REM is a variation of SEM in which the beam of electrons is reflected off the surface of the sample, rather than scattered back from it. This technique can provide information about the surface chemistry and composition of materials.

Electron microscopy has a wide range of applications in biology, medicine, and materials science, including the study of cellular structure and function, disease diagnosis, and the development of new materials and technologies.

CHO cells, or Chinese Hamster Ovary cells, are a type of immortalized cell line that are commonly used in scientific research and biotechnology. They were originally derived from the ovaries of a female Chinese hamster (Cricetulus griseus) in the 1950s.

CHO cells have several characteristics that make them useful for laboratory experiments. They can grow and divide indefinitely under appropriate conditions, which allows researchers to culture large quantities of them for study. Additionally, CHO cells are capable of expressing high levels of recombinant proteins, making them a popular choice for the production of therapeutic drugs, vaccines, and other biologics.

In particular, CHO cells have become a workhorse in the field of biotherapeutics, with many approved monoclonal antibody-based therapies being produced using these cells. The ability to genetically modify CHO cells through various methods has further expanded their utility in research and industrial applications.

It is important to note that while CHO cells are widely used in scientific research, they may not always accurately represent human cell behavior or respond to drugs and other compounds in the same way as human cells do. Therefore, results obtained using CHO cells should be validated in more relevant systems when possible.

Integrin αXβ2, also known as CD11c/CD18 or complement receptor 4 (CR4), is a heterodimeric integrin that is widely expressed on the surface of various leukocytes, including dendritic cells, monocytes, macrophages, and some subsets of T cells and NK cells. This integrin plays crucial roles in cell-cell adhesion, cell migration, and signaling transduction during immune responses.

Integrin αXβ2 recognizes several ligands, including the complement component iC3b, fibrinogen, and factor X. The binding of these ligands to αXβ2 triggers various intracellular signaling pathways that regulate cell activation, differentiation, and effector functions.

In summary, Integrin αXβ2 is a vital integrin involved in the regulation of immune responses by mediating leukocyte adhesion, migration, and activation.

Mannans are a type of complex carbohydrate, specifically a heteropolysaccharide, that are found in the cell walls of certain plants, algae, and fungi. They consist of chains of mannose sugars linked together, often with other sugar molecules such as glucose or galactose.

Mannans have various biological functions, including serving as a source of energy for microorganisms that can break them down. In some cases, mannans can also play a role in the immune response and are used as a component of vaccines to stimulate an immune response.

In the context of medicine, mannans may be relevant in certain conditions such as gut dysbiosis or allergic reactions to foods containing mannans. Additionally, some research has explored the potential use of mannans as a delivery vehicle for drugs or other therapeutic agents.

Clusterin is a protein that is widely expressed in many tissues and body fluids, including the tears, blood plasma, seminal fluid, milk, and cerebrospinal fluid. It is also known as apolipoprotein J or sulfated glycoprotein 2. Clusterin has diverse functions, including cell-cell communication, lipid transport, and protection against oxidative stress.

In the context of medicine and disease, clusterin has been studied for its potential role in several pathological processes, such as neurodegeneration, inflammation, cancer, and aging. In particular, clusterin has been implicated in the development and progression of various types of cancer, including prostate, breast, ovarian, and lung cancer. It is thought to contribute to tumor growth, invasion, and metastasis by promoting cell survival, angiogenesis, and resistance to chemotherapy.

Therefore, clusterin has been considered as a potential therapeutic target for cancer treatment, and several strategies have been developed to inhibit its expression or activity. However, more research is needed to fully understand the molecular mechanisms of clusterin in health and disease, and to translate these findings into effective clinical interventions.

Serum globulins are a group of proteins present in the liquid portion of blood, known as serum. They are produced by the immune system in response to foreign substances such as bacteria, viruses, and allergens. Serum globulins include several types of immunoglobulins (antibodies), complement components, and other proteins involved in the immune response.

The serum globulin level is often measured as part of a complete blood count (CBC) or a protein electrophoresis test. An elevated serum globulin level may indicate an ongoing infection, inflammation, or an autoimmune disorder. Conversely, a decreased level may suggest a liver or kidney disease, or a malnutrition condition. It is important to note that the interpretation of serum globulin levels should be done in conjunction with other laboratory and clinical findings.

Streptococcus pneumoniae, also known as the pneumococcus, is a gram-positive, alpha-hemolytic bacterium frequently found in the upper respiratory tract of healthy individuals. It is a leading cause of community-acquired pneumonia and can also cause other infectious diseases such as otitis media (ear infection), sinusitis, meningitis, and bacteremia (bloodstream infection). The bacteria are encapsulated, and there are over 90 serotypes based on variations in the capsular polysaccharide. Some serotypes are more virulent or invasive than others, and the polysaccharide composition is crucial for vaccine development. S. pneumoniae infection can be treated with antibiotics, but the emergence of drug-resistant strains has become a significant global health concern.

An epitope is a specific region on the surface of an antigen (a molecule that can trigger an immune response) that is recognized by an antibody, B-cell receptor, or T-cell receptor. It is also commonly referred to as an antigenic determinant. Epitopes are typically composed of linear amino acid sequences or conformational structures made up of discontinuous amino acids in the antigen. They play a crucial role in the immune system's ability to differentiate between self and non-self molecules, leading to the targeted destruction of foreign substances like viruses and bacteria. Understanding epitopes is essential for developing vaccines, diagnostic tests, and immunotherapies.

An erythrocyte, also known as a red blood cell, is a type of cell that circulates in the blood and is responsible for transporting oxygen throughout the body. The erythrocyte membrane refers to the thin, flexible barrier that surrounds the erythrocyte and helps to maintain its shape and stability.

The erythrocyte membrane is composed of a lipid bilayer, which contains various proteins and carbohydrates. These components help to regulate the movement of molecules into and out of the erythrocyte, as well as provide structural support and protection for the cell.

The main lipids found in the erythrocyte membrane are phospholipids and cholesterol, which are arranged in a bilayer structure with the hydrophilic (water-loving) heads facing outward and the hydrophobic (water-fearing) tails facing inward. This arrangement helps to maintain the integrity of the membrane and prevent the leakage of cellular components.

The proteins found in the erythrocyte membrane include integral proteins, which span the entire width of the membrane, and peripheral proteins, which are attached to the inner or outer surface of the membrane. These proteins play a variety of roles, such as transporting molecules across the membrane, maintaining the shape of the erythrocyte, and interacting with other cells and proteins in the body.

The carbohydrates found in the erythrocyte membrane are attached to the outer surface of the membrane and help to identify the cell as part of the body's own immune system. They also play a role in cell-cell recognition and adhesion.

Overall, the erythrocyte membrane is a complex and dynamic structure that plays a critical role in maintaining the function and integrity of red blood cells.

'Gene expression regulation' refers to the processes that control whether, when, and where a particular gene is expressed, meaning the production of a specific protein or functional RNA encoded by that gene. This complex mechanism can be influenced by various factors such as transcription factors, chromatin remodeling, DNA methylation, non-coding RNAs, and post-transcriptional modifications, among others. Proper regulation of gene expression is crucial for normal cellular function, development, and maintaining homeostasis in living organisms. Dysregulation of gene expression can lead to various diseases, including cancer and genetic disorders.

Gene deletion is a type of mutation where a segment of DNA, containing one or more genes, is permanently lost or removed from a chromosome. This can occur due to various genetic mechanisms such as homologous recombination, non-homologous end joining, or other types of genomic rearrangements.

The deletion of a gene can have varying effects on the organism, depending on the function of the deleted gene and its importance for normal physiological processes. If the deleted gene is essential for survival, the deletion may result in embryonic lethality or developmental abnormalities. However, if the gene is non-essential or has redundant functions, the deletion may not have any noticeable effects on the organism's phenotype.

Gene deletions can also be used as a tool in genetic research to study the function of specific genes and their role in various biological processes. For example, researchers may use gene deletion techniques to create genetically modified animal models to investigate the impact of gene deletion on disease progression or development.

DNA Sequence Analysis is the systematic determination of the order of nucleotides in a DNA molecule. It is a critical component of modern molecular biology, genetics, and genetic engineering. The process involves determining the exact order of the four nucleotide bases - adenine (A), guanine (G), cytosine (C), and thymine (T) - in a DNA molecule or fragment. This information is used in various applications such as identifying gene mutations, studying evolutionary relationships, developing molecular markers for breeding, and diagnosing genetic diseases.

The process of DNA Sequence Analysis typically involves several steps, including DNA extraction, PCR amplification (if necessary), purification, sequencing reaction, and electrophoresis. The resulting data is then analyzed using specialized software to determine the exact sequence of nucleotides.

In recent years, high-throughput DNA sequencing technologies have revolutionized the field of genomics, enabling the rapid and cost-effective sequencing of entire genomes. This has led to an explosion of genomic data and new insights into the genetic basis of many diseases and traits.

Histocompatibility antigens, also known as human leukocyte antigens (HLAs), are proteins found on the surface of most cells in the body. They play a critical role in the immune system's ability to differentiate between "self" and "non-self" cells. Histocompatibility antigens are encoded by a group of genes called the major histocompatibility complex (MHC).

There are two main types of histocompatibility antigens: class I and class II. Class I antigens are found on almost all nucleated cells, while class II antigens are primarily expressed on immune cells such as B cells, macrophages, and dendritic cells. These antigens present pieces of proteins (peptides) from both inside and outside the cell to T-cells, a type of white blood cell that plays a central role in the immune response.

When foreign peptides are presented to T-cells by histocompatibility antigens, it triggers an immune response aimed at eliminating the threat. This is why histocompatibility antigens are so important in organ transplantation - if the donor's and recipient's antigens do not match closely enough, the recipient's immune system may recognize the transplanted organ as foreign and attack it.

Understanding the role of histocompatibility antigens has been crucial in developing techniques for matching donors and recipients in organ transplantation, as well as in diagnosing and treating various autoimmune diseases and cancers.

Immunoglobulin A (IgA) is a type of antibody that plays a crucial role in the immune function of the human body. It is primarily found in external secretions, such as saliva, tears, breast milk, and sweat, as well as in mucous membranes lining the respiratory and gastrointestinal tracts. IgA exists in two forms: a monomeric form found in serum and a polymeric form found in secretions.

The primary function of IgA is to provide immune protection at mucosal surfaces, which are exposed to various environmental antigens, such as bacteria, viruses, parasites, and allergens. By doing so, it helps prevent the entry and colonization of pathogens into the body, reducing the risk of infections and inflammation.

IgA functions by binding to antigens present on the surface of pathogens or allergens, forming immune complexes that can neutralize their activity. These complexes are then transported across the epithelial cells lining mucosal surfaces and released into the lumen, where they prevent the adherence and invasion of pathogens.

In summary, Immunoglobulin A (IgA) is a vital antibody that provides immune defense at mucosal surfaces by neutralizing and preventing the entry of harmful antigens into the body.

Inbred strains of mice are defined as lines of mice that have been brother-sister mated for at least 20 consecutive generations. This results in a high degree of homozygosity, where the mice of an inbred strain are genetically identical to one another, with the exception of spontaneous mutations.

Inbred strains of mice are widely used in biomedical research due to their genetic uniformity and stability, which makes them useful for studying the genetic basis of various traits, diseases, and biological processes. They also provide a consistent and reproducible experimental system, as compared to outbred or genetically heterogeneous populations.

Some commonly used inbred strains of mice include C57BL/6J, BALB/cByJ, DBA/2J, and 129SvEv. Each strain has its own unique genetic background and phenotypic characteristics, which can influence the results of experiments. Therefore, it is important to choose the appropriate inbred strain for a given research question.

Recombinant fusion proteins are artificially created biomolecules that combine the functional domains or properties of two or more different proteins into a single protein entity. They are generated through recombinant DNA technology, where the genes encoding the desired protein domains are linked together and expressed as a single, chimeric gene in a host organism, such as bacteria, yeast, or mammalian cells.

The resulting fusion protein retains the functional properties of its individual constituent proteins, allowing for novel applications in research, diagnostics, and therapeutics. For instance, recombinant fusion proteins can be designed to enhance protein stability, solubility, or immunogenicity, making them valuable tools for studying protein-protein interactions, developing targeted therapies, or generating vaccines against infectious diseases or cancer.

Examples of recombinant fusion proteins include:

1. Etaglunatide (ABT-523): A soluble Fc fusion protein that combines the heavy chain fragment crystallizable region (Fc) of an immunoglobulin with the extracellular domain of the human interleukin-6 receptor (IL-6R). This fusion protein functions as a decoy receptor, neutralizing IL-6 and its downstream signaling pathways in rheumatoid arthritis.
2. Etanercept (Enbrel): A soluble TNF receptor p75 Fc fusion protein that binds to tumor necrosis factor-alpha (TNF-α) and inhibits its proinflammatory activity, making it a valuable therapeutic option for treating autoimmune diseases like rheumatoid arthritis, ankylosing spondylitis, and psoriasis.
3. Abatacept (Orencia): A fusion protein consisting of the extracellular domain of cytotoxic T-lymphocyte antigen 4 (CTLA-4) linked to the Fc region of an immunoglobulin, which downregulates T-cell activation and proliferation in autoimmune diseases like rheumatoid arthritis.
4. Belimumab (Benlysta): A monoclonal antibody that targets B-lymphocyte stimulator (BLyS) protein, preventing its interaction with the B-cell surface receptor and inhibiting B-cell activation in systemic lupus erythematosus (SLE).
5. Romiplostim (Nplate): A fusion protein consisting of a thrombopoietin receptor agonist peptide linked to an immunoglobulin Fc region, which stimulates platelet production in patients with chronic immune thrombocytopenia (ITP).
6. Darbepoetin alfa (Aranesp): A hyperglycosylated erythropoiesis-stimulating protein that functions as a longer-acting form of recombinant human erythropoietin, used to treat anemia in patients with chronic kidney disease or cancer.
7. Palivizumab (Synagis): A monoclonal antibody directed against the F protein of respiratory syncytial virus (RSV), which prevents RSV infection and is administered prophylactically to high-risk infants during the RSV season.
8. Ranibizumab (Lucentis): A recombinant humanized monoclonal antibody fragment that binds and inhibits vascular endothelial growth factor A (VEGF-A), used in the treatment of age-related macular degeneration, diabetic retinopathy, and other ocular disorders.
9. Cetuximab (Erbitux): A chimeric monoclonal antibody that binds to epidermal growth factor receptor (EGFR), used in the treatment of colorectal cancer and head and neck squamous cell carcinoma.
10. Adalimumab (Humira): A fully humanized monoclonal antibody that targets tumor necrosis factor-alpha (TNF-α), used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriasis, and Crohn's disease.
11. Bevacizumab (Avastin): A recombinant humanized monoclonal antibody that binds to VEGF-A, used in the treatment of various cancers, including colorectal, lung, breast, and kidney cancer.
12. Trastuzumab (Herceptin): A humanized monoclonal antibody that targets HER2/neu receptor, used in the treatment of breast cancer.
13. Rituximab (Rituxan): A chimeric monoclonal antibody that binds to CD20 antigen on B cells, used in the treatment of non-Hodgkin's lymphoma and rheumatoid arthritis.
14. Palivizumab (Synagis): A humanized monoclonal antibody that binds to the F protein of respiratory syncytial virus, used in the prevention of respiratory syncytial virus infection in high-risk infants.
15. Infliximab (Remicade): A chimeric monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including Crohn's disease, ulcerative colitis, rheumatoid arthritis, and ankylosing spondylitis.
16. Natalizumab (Tysabri): A humanized monoclonal antibody that binds to α4β1 integrin, used in the treatment of multiple sclerosis and Crohn's disease.
17. Adalimumab (Humira): A fully human monoclonal antibody that targets TNF-α, used in the treatment of various inflammatory diseases, including rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, Crohn's disease, and ulcerative colitis.
18. Golimumab (Simponi): A fully human monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis.
19. Certolizumab pegol (Cimzia): A PEGylated Fab' fragment of a humanized monoclonal antibody that targets TNF-α, used in the treatment of rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and Crohn's disease.
20. Ustekinumab (Stelara): A fully human monoclonal antibody that targets IL-12 and IL-23, used in the treatment of psoriasis, psoriatic arthritis, and Crohn's disease.
21. Secukinumab (Cosentyx): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis, psoriatic arthritis, and ankylosing spondylitis.
22. Ixekizumab (Taltz): A fully human monoclonal antibody that targets IL-17A, used in the treatment of psoriasis and psoriatic arthritis.
23. Brodalumab (Siliq): A fully human monoclonal antibody that targets IL-17 receptor A, used in the treatment of psoriasis.
24. Sarilumab (Kevzara): A fully human monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis.
25. Tocilizumab (Actemra): A humanized monoclonal antibody that targets the IL-6 receptor, used in the treatment of rheumatoid arthritis, systemic juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis, and chimeric antigen receptor T-cell-induced cytokine release syndrome.
26. Siltuximab (Sylvant): A chimeric monoclonal antibody that targets IL-6, used in the treatment of multicentric Castleman disease.
27. Satralizumab (Enspryng): A humanized monoclonal antibody that targets IL-6 receptor alpha, used in the treatment of neuromyelitis optica spectrum disorder.
28. Sirukumab (Plivensia): A human monoclonal antibody that targets IL-6, used in the treatment

Neisseria meningitidis is a Gram-negative, aerobic, bean-shaped diplococcus bacterium. It is one of the leading causes of bacterial meningitis and sepsis (known as meningococcal disease) worldwide. The bacteria can be found in the back of the nose and throat of approximately 10-25% of the general population, particularly in children, teenagers, and young adults, without causing any symptoms or illness. However, when the bacterium invades the bloodstream and spreads to the brain or spinal cord, it can lead to life-threatening infections such as meningitis (inflammation of the membranes surrounding the brain and spinal cord) and septicemia (blood poisoning).

Neisseria meningitidis is classified into 12 serogroups based on the chemical structure of their capsular polysaccharides. The six major serogroups that cause most meningococcal disease worldwide are A, B, C, W, X, and Y. Vaccines are available to protect against some or all of these serogroups.

Meningococcal disease can progress rapidly, leading to severe symptoms such as high fever, headache, stiff neck, confusion, nausea, vomiting, and a rash consisting of purple or red spots. Immediate medical attention is required if someone experiences these symptoms, as meningococcal disease can cause permanent disabilities or death within hours if left untreated.

Passive immunization is a type of temporary immunity that is transferred to an individual through the injection of antibodies produced outside of the body, rather than through the active production of antibodies in the body in response to vaccination or infection. This can be done through the administration of preformed antibodies, such as immune globulins, which contain a mixture of antibodies that provide immediate protection against specific diseases.

Passive immunization is often used in situations where individuals have been exposed to a disease and do not have time to develop their own active immune response, or in cases where individuals are unable to produce an adequate immune response due to certain medical conditions. It can also be used as a short-term measure to provide protection until an individual can receive a vaccination that will confer long-term immunity.

Passive immunization provides immediate protection against disease, but the protection is typically short-lived, lasting only a few weeks or months. This is because the transferred antibodies are gradually broken down and eliminated by the body over time. In contrast, active immunization confers long-term immunity through the production of memory cells that can mount a rapid and effective immune response upon re-exposure to the same pathogen in the future.

Meningococcal infections are caused by the bacterium Neisseria meningitidis, also known as meningococcus. These infections can take several forms, but the most common are meningitis (inflammation of the membranes surrounding the brain and spinal cord) and septicemia (bloodstream infection). Meningococcal infections are contagious and can spread through respiratory droplets or close contact with an infected person. They can be serious and potentially life-threatening, requiring prompt medical attention and treatment with antibiotics. Symptoms of meningococcal meningitis may include fever, headache, stiff neck, and sensitivity to light, while symptoms of septicemia may include fever, chills, rash, and severe muscle pain. Vaccination is available to prevent certain strains of meningococcal disease.

Reperfusion injury is a complex pathophysiological process that occurs when blood flow is restored to previously ischemic tissues, leading to further tissue damage. This phenomenon can occur in various clinical settings such as myocardial infarction (heart attack), stroke, or peripheral artery disease after an intervention aimed at restoring perfusion.

The restoration of blood flow leads to the generation of reactive oxygen species (ROS) and inflammatory mediators, which can cause oxidative stress, cellular damage, and activation of the immune system. This results in a cascade of events that may lead to microvascular dysfunction, capillary leakage, and tissue edema, further exacerbating the injury.

Reperfusion injury is an important consideration in the management of ischemic events, as interventions aimed at restoring blood flow must be carefully balanced with potential harm from reperfusion injury. Strategies to mitigate reperfusion injury include ischemic preconditioning (exposing the tissue to short periods of ischemia before a prolonged ischemic event), ischemic postconditioning (applying brief periods of ischemia and reperfusion after restoring blood flow), remote ischemic preconditioning (ischemia applied to a distant organ or tissue to protect the target organ), and pharmacological interventions that scavenge ROS, reduce inflammation, or improve microvascular function.

Hemagglutination tests are laboratory procedures used to detect the presence of antibodies or antigens in a sample, typically in blood serum. These tests rely on the ability of certain substances, such as viruses or bacteria, to agglutinate (clump together) red blood cells.

In a hemagglutination test, a small amount of the patient's serum is mixed with a known quantity of red blood cells that have been treated with a specific antigen. If the patient has antibodies against that antigen in their serum, they will bind to the antigens on the red blood cells and cause them to agglutinate. This clumping can be observed visually, indicating a positive test result.

Hemagglutination tests are commonly used to diagnose infectious diseases caused by viruses or bacteria that have hemagglutinating properties, such as influenza, parainfluenza, and HIV. They can also be used in blood typing and cross-matching before transfusions.

Chromium isotopes are different forms of the chemical element Chromium (Cr), which have different numbers of neutrons in their atomic nuclei. This results in each isotope having a different atomic mass, although they all have the same number of protons (24) and therefore share the same chemical properties.

The most common and stable chromium isotopes are Chromium-52 (Cr-52), Chromium-53 (Cr-53), Chromium-54 (Cr-54), and Chromium-56 (Cr-56). The other less abundant isotopes of Chromium, such as Chromium-50 (Cr-50) and Chromium-51 (Cr-51), are radioactive and undergo decay to become stable isotopes.

Chromium is an essential trace element for human health, playing a role in the metabolism of carbohydrates, lipids, and proteins. It is also used in various industrial applications, such as in the production of stainless steel and other alloys.

Phylogeny is the evolutionary history and relationship among biological entities, such as species or genes, based on their shared characteristics. In other words, it refers to the branching pattern of evolution that shows how various organisms have descended from a common ancestor over time. Phylogenetic analysis involves constructing a tree-like diagram called a phylogenetic tree, which depicts the inferred evolutionary relationships among organisms or genes based on molecular sequence data or other types of characters. This information is crucial for understanding the diversity and distribution of life on Earth, as well as for studying the emergence and spread of diseases.

Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.

A kidney, in medical terms, is one of two bean-shaped organs located in the lower back region of the body. They are essential for maintaining homeostasis within the body by performing several crucial functions such as:

1. Regulation of water and electrolyte balance: Kidneys help regulate the amount of water and various electrolytes like sodium, potassium, and calcium in the bloodstream to maintain a stable internal environment.

2. Excretion of waste products: They filter waste products from the blood, including urea (a byproduct of protein metabolism), creatinine (a breakdown product of muscle tissue), and other harmful substances that result from normal cellular functions or external sources like medications and toxins.

3. Endocrine function: Kidneys produce several hormones with important roles in the body, such as erythropoietin (stimulates red blood cell production), renin (regulates blood pressure), and calcitriol (activated form of vitamin D that helps regulate calcium homeostasis).

4. pH balance regulation: Kidneys maintain the proper acid-base balance in the body by excreting either hydrogen ions or bicarbonate ions, depending on whether the blood is too acidic or too alkaline.

5. Blood pressure control: The kidneys play a significant role in regulating blood pressure through the renin-angiotensin-aldosterone system (RAAS), which constricts blood vessels and promotes sodium and water retention to increase blood volume and, consequently, blood pressure.

Anatomically, each kidney is approximately 10-12 cm long, 5-7 cm wide, and 3 cm thick, with a weight of about 120-170 grams. They are surrounded by a protective layer of fat and connected to the urinary system through the renal pelvis, ureters, bladder, and urethra.

Protein conformation refers to the specific three-dimensional shape that a protein molecule assumes due to the spatial arrangement of its constituent amino acid residues and their associated chemical groups. This complex structure is determined by several factors, including covalent bonds (disulfide bridges), hydrogen bonds, van der Waals forces, and ionic bonds, which help stabilize the protein's unique conformation.

Protein conformations can be broadly classified into two categories: primary, secondary, tertiary, and quaternary structures. The primary structure represents the linear sequence of amino acids in a polypeptide chain. The secondary structure arises from local interactions between adjacent amino acid residues, leading to the formation of recurring motifs such as α-helices and β-sheets. Tertiary structure refers to the overall three-dimensional folding pattern of a single polypeptide chain, while quaternary structure describes the spatial arrangement of multiple folded polypeptide chains (subunits) that interact to form a functional protein complex.

Understanding protein conformation is crucial for elucidating protein function, as the specific three-dimensional shape of a protein directly influences its ability to interact with other molecules, such as ligands, nucleic acids, or other proteins. Any alterations in protein conformation due to genetic mutations, environmental factors, or chemical modifications can lead to loss of function, misfolding, aggregation, and disease states like neurodegenerative disorders and cancer.

Serine endopeptidases are a type of enzymes that cleave peptide bonds within proteins (endopeptidases) and utilize serine as the nucleophilic amino acid in their active site for catalysis. These enzymes play crucial roles in various biological processes, including digestion, blood coagulation, and programmed cell death (apoptosis). Examples of serine endopeptidases include trypsin, chymotrypsin, thrombin, and elastase.

Chemotaxis, Leukocyte is the movement of leukocytes (white blood cells) towards a higher concentration of a particular chemical substance, known as a chemotactic factor. This process plays a crucial role in the immune system's response to infection and injury.

When there is an infection or tissue damage, certain cells release chemotactic factors, which are small molecules or proteins that can attract leukocytes to the site of inflammation. Leukocytes have receptors on their surface that can detect these chemotactic factors and move towards them through a process called chemotaxis.

Once they reach the site of inflammation, leukocytes can help eliminate pathogens or damaged cells by phagocytosis (engulfing and destroying) or releasing toxic substances that kill the invading microorganisms. Chemotaxis is an essential part of the immune system's defense mechanisms and helps to maintain tissue homeostasis and prevent the spread of infection.

Temperature, in a medical context, is a measure of the degree of hotness or coldness of a body or environment. It is usually measured using a thermometer and reported in degrees Celsius (°C), degrees Fahrenheit (°F), or kelvin (K). In the human body, normal core temperature ranges from about 36.5-37.5°C (97.7-99.5°F) when measured rectally, and can vary slightly depending on factors such as time of day, physical activity, and menstrual cycle. Elevated body temperature is a common sign of infection or inflammation, while abnormally low body temperature can indicate hypothermia or other medical conditions.

Snake venoms are complex mixtures of bioactive compounds produced by specialized glands in snakes. They primarily consist of proteins and peptides, including enzymes, neurotoxins, hemotoxins, cytotoxins, and cardiotoxins. These toxins can cause a variety of pharmacological effects on the victim's body, such as disruption of the nervous system, blood coagulation, muscle function, and cell membrane integrity, ultimately leading to tissue damage and potentially death. The composition of snake venoms varies widely among different species, making each species' venom unique in its toxicity profile.

Rheumatoid factor (RF) is an autoantibody, specifically an immunoglobulin M (IgM) antibody, that can be detected in the blood serum of some people with rheumatoid arthritis (RA), other inflammatory conditions, and infectious diseases. RF targets the Fc portion of IgG, leading to immune complex formation and subsequent inflammation, which contributes to the pathogenesis of RA. However, not all patients with RA test positive for RF, and its presence does not necessarily confirm a diagnosis of RA. Other conditions can also lead to elevated RF levels, such as infections, liver diseases, and certain malignancies. Therefore, the interpretation of RF results should be considered alongside other clinical, laboratory, and imaging findings for an accurate diagnosis and appropriate management.

Isoantibodies are antibodies produced by the immune system that recognize and react to antigens (markers) found on the cells or tissues of another individual of the same species. These antigens are typically proteins or carbohydrates present on the surface of red blood cells, but they can also be found on other cell types.

Isoantibodies are formed when an individual is exposed to foreign antigens, usually through blood transfusions, pregnancy, or tissue transplantation. The exposure triggers the immune system to produce specific antibodies against these antigens, which can cause a harmful immune response if the individual receives another transfusion or transplant from the same donor in the future.

There are two main types of isoantibodies:

1. Agglutinins: These are IgM antibodies that cause red blood cells to clump together (agglutinate) when mixed with the corresponding antigen. They develop rapidly after exposure and can cause immediate transfusion reactions or hemolytic disease of the newborn in pregnant women.
2. Hemolysins: These are IgG antibodies that destroy red blood cells by causing their membranes to become more permeable, leading to lysis (bursting) of the cells and release of hemoglobin into the plasma. They take longer to develop but can cause delayed transfusion reactions or hemolytic disease of the newborn in pregnant women.

Isoantibodies are detected through blood tests, such as the crossmatch test, which determines compatibility between a donor's and recipient's blood before transfusions or transplants.

Complementary DNA (cDNA) is a type of DNA that is synthesized from a single-stranded RNA molecule through the process of reverse transcription. In this process, the enzyme reverse transcriptase uses an RNA molecule as a template to synthesize a complementary DNA strand. The resulting cDNA is therefore complementary to the original RNA molecule and is a copy of its coding sequence, but it does not contain non-coding regions such as introns that are present in genomic DNA.

Complementary DNA is often used in molecular biology research to study gene expression, protein function, and other genetic phenomena. For example, cDNA can be used to create cDNA libraries, which are collections of cloned cDNA fragments that represent the expressed genes in a particular cell type or tissue. These libraries can then be screened for specific genes or gene products of interest. Additionally, cDNA can be used to produce recombinant proteins in heterologous expression systems, allowing researchers to study the structure and function of proteins that may be difficult to express or purify from their native sources.

DNA primers are short single-stranded DNA molecules that serve as a starting point for DNA synthesis. They are typically used in laboratory techniques such as the polymerase chain reaction (PCR) and DNA sequencing. The primer binds to a complementary sequence on the DNA template through base pairing, providing a free 3'-hydroxyl group for the DNA polymerase enzyme to add nucleotides and synthesize a new strand of DNA. This allows for specific and targeted amplification or analysis of a particular region of interest within a larger DNA molecule.

Phagocytes are a type of white blood cell in the immune system that engulf and destroy foreign particles, microbes, and cellular debris. They play a crucial role in the body's defense against infection and tissue damage. There are several types of phagocytes, including neutrophils, monocytes, macrophages, and dendritic cells. These cells have receptors that recognize and bind to specific molecules on the surface of foreign particles or microbes, allowing them to engulf and digest the invaders. Phagocytosis is an important mechanism for maintaining tissue homeostasis and preventing the spread of infection.

Gene expression is the process by which the information encoded in a gene is used to synthesize a functional gene product, such as a protein or RNA molecule. This process involves several steps: transcription, RNA processing, and translation. During transcription, the genetic information in DNA is copied into a complementary RNA molecule, known as messenger RNA (mRNA). The mRNA then undergoes RNA processing, which includes adding a cap and tail to the mRNA and splicing out non-coding regions called introns. The resulting mature mRNA is then translated into a protein on ribosomes in the cytoplasm through the process of translation.

The regulation of gene expression is a complex and highly controlled process that allows cells to respond to changes in their environment, such as growth factors, hormones, and stress signals. This regulation can occur at various stages of gene expression, including transcriptional activation or repression, RNA processing, mRNA stability, and translation. Dysregulation of gene expression has been implicated in many diseases, including cancer, genetic disorders, and neurological conditions.

The Coombs test is a laboratory procedure used to detect the presence of antibodies on the surface of red blood cells (RBCs). It is named after the scientist, Robin Coombs, who developed the test. There are two types of Coombs tests: direct and indirect.

1. Direct Coombs Test (DCT): This test is used to detect the presence of antibodies directly attached to the surface of RBCs. It is often used to diagnose hemolytic anemia, a condition in which RBCs are destroyed prematurely, leading to anemia. A positive DCT indicates that the patient's RBCs have been coated with antibodies, which can occur due to various reasons such as autoimmune disorders, blood transfusion reactions, or drug-induced immune hemolysis.
2. Indirect Coombs Test (ICT): This test is used to detect the presence of antibodies in the patient's serum that can agglutinate (clump) foreign RBCs. It is commonly used before blood transfusions or during pregnancy to determine if the patient has antibodies against the RBCs of a potential donor or fetus, respectively. A positive ICT indicates that the patient's serum contains antibodies capable of binding to and agglutinating foreign RBCs.

In summary, the Coombs test is a crucial diagnostic tool in identifying various hemolytic disorders and ensuring safe blood transfusions by detecting the presence of harmful antibodies against RBCs.

Genotype, in genetics, refers to the complete heritable genetic makeup of an individual organism, including all of its genes. It is the set of instructions contained in an organism's DNA for the development and function of that organism. The genotype is the basis for an individual's inherited traits, and it can be contrasted with an individual's phenotype, which refers to the observable physical or biochemical characteristics of an organism that result from the expression of its genes in combination with environmental influences.

It is important to note that an individual's genotype is not necessarily identical to their genetic sequence. Some genes have multiple forms called alleles, and an individual may inherit different alleles for a given gene from each parent. The combination of alleles that an individual inherits for a particular gene is known as their genotype for that gene.

Understanding an individual's genotype can provide important information about their susceptibility to certain diseases, their response to drugs and other treatments, and their risk of passing on inherited genetic disorders to their offspring.

An allele is a variant form of a gene that is located at a specific position on a specific chromosome. Alleles are alternative forms of the same gene that arise by mutation and are found at the same locus or position on homologous chromosomes.

Each person typically inherits two copies of each gene, one from each parent. If the two alleles are identical, a person is said to be homozygous for that trait. If the alleles are different, the person is heterozygous.

For example, the ABO blood group system has three alleles, A, B, and O, which determine a person's blood type. If a person inherits two A alleles, they will have type A blood; if they inherit one A and one B allele, they will have type AB blood; if they inherit two B alleles, they will have type B blood; and if they inherit two O alleles, they will have type O blood.

Alleles can also influence traits such as eye color, hair color, height, and other physical characteristics. Some alleles are dominant, meaning that only one copy of the allele is needed to express the trait, while others are recessive, meaning that two copies of the allele are needed to express the trait.

A Structure-Activity Relationship (SAR) in the context of medicinal chemistry and pharmacology refers to the relationship between the chemical structure of a drug or molecule and its biological activity or effect on a target protein, cell, or organism. SAR studies aim to identify patterns and correlations between structural features of a compound and its ability to interact with a specific biological target, leading to a desired therapeutic response or undesired side effects.

By analyzing the SAR, researchers can optimize the chemical structure of lead compounds to enhance their potency, selectivity, safety, and pharmacokinetic properties, ultimately guiding the design and development of novel drugs with improved efficacy and reduced toxicity.

Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific regions of DNA. It enables the production of thousands to millions of copies of a particular DNA sequence in a rapid and efficient manner, making it an essential tool in various fields such as molecular biology, medical diagnostics, forensic science, and research.

The PCR process involves repeated cycles of heating and cooling to separate the DNA strands, allow primers (short sequences of single-stranded DNA) to attach to the target regions, and extend these primers using an enzyme called Taq polymerase, resulting in the exponential amplification of the desired DNA segment.

In a medical context, PCR is often used for detecting and quantifying specific pathogens (viruses, bacteria, fungi, or parasites) in clinical samples, identifying genetic mutations or polymorphisms associated with diseases, monitoring disease progression, and evaluating treatment effectiveness.

A gene is a specific sequence of nucleotides in DNA that carries genetic information. Genes are the fundamental units of heredity and are responsible for the development and function of all living organisms. They code for proteins or RNA molecules, which carry out various functions within cells and are essential for the structure, function, and regulation of the body's tissues and organs.

Each gene has a specific location on a chromosome, and each person inherits two copies of every gene, one from each parent. Variations in the sequence of nucleotides in a gene can lead to differences in traits between individuals, including physical characteristics, susceptibility to disease, and responses to environmental factors.

Medical genetics is the study of genes and their role in health and disease. It involves understanding how genes contribute to the development and progression of various medical conditions, as well as identifying genetic risk factors and developing strategies for prevention, diagnosis, and treatment.

Chromosome mapping, also known as physical mapping, is the process of determining the location and order of specific genes or genetic markers on a chromosome. This is typically done by using various laboratory techniques to identify landmarks along the chromosome, such as restriction enzyme cutting sites or patterns of DNA sequence repeats. The resulting map provides important information about the organization and structure of the genome, and can be used for a variety of purposes, including identifying the location of genes associated with genetic diseases, studying evolutionary relationships between organisms, and developing genetic markers for use in breeding or forensic applications.

Streptococcus pyogenes is a Gram-positive, beta-hemolytic streptococcus bacterium that causes various suppurative (pus-forming) and nonsuppurative infections in humans. It is also known as group A Streptococcus (GAS) due to its ability to produce the M protein, which confers type-specific antigenicity and allows for serological classification into more than 200 distinct Lancefield groups.

S. pyogenes is responsible for a wide range of clinical manifestations, including pharyngitis (strep throat), impetigo, cellulitis, erysipelas, scarlet fever, rheumatic fever, and acute poststreptococcal glomerulonephritis. In rare cases, it can lead to invasive diseases such as necrotizing fasciitis (flesh-eating disease) and streptococcal toxic shock syndrome (STSS).

The bacterium is typically transmitted through respiratory droplets or direct contact with infected skin lesions. Effective prevention strategies include good hygiene practices, such as frequent handwashing and avoiding sharing personal items, as well as prompt recognition and treatment of infections to prevent spread.

C-reactive protein (CRP) is a protein produced by the liver in response to inflammation or infection in the body. It is named after its ability to bind to the C-polysaccharide of pneumococcus, a type of bacteria. CRP levels can be measured with a simple blood test and are often used as a marker of inflammation or infection. Elevated CRP levels may indicate a variety of conditions, including infections, tissue damage, and chronic diseases such as rheumatoid arthritis and cancer. However, it is important to note that CRP is not specific to any particular condition, so additional tests are usually needed to make a definitive diagnosis.

Restriction mapping is a technique used in molecular biology to identify the location and arrangement of specific restriction endonuclease recognition sites within a DNA molecule. Restriction endonucleases are enzymes that cut double-stranded DNA at specific sequences, producing fragments of various lengths. By digesting the DNA with different combinations of these enzymes and analyzing the resulting fragment sizes through techniques such as agarose gel electrophoresis, researchers can generate a restriction map - a visual representation of the locations and distances between recognition sites on the DNA molecule. This information is crucial for various applications, including cloning, genome analysis, and genetic engineering.

Immunoglobulin (Ig) Fab fragments are the antigen-binding portions of an antibody that result from the digestion of the whole antibody molecule by enzymes such as papain. An antibody, also known as an immunoglobulin, is a Y-shaped protein produced by the immune system to identify and neutralize foreign substances like bacteria, viruses, or toxins. The antibody has two identical antigen-binding sites, located at the tips of the two shorter arms, which can bind specifically to a target antigen.

Fab fragments are formed when an antibody is cleaved by papain, resulting in two Fab fragments and one Fc fragment. Each Fab fragment contains one antigen-binding site, composed of a variable region (Fv) and a constant region (C). The Fv region is responsible for the specificity and affinity of the antigen binding, while the C region contributes to the effector functions of the antibody.

Fab fragments are often used in various medical applications, such as immunodiagnostics and targeted therapies, due to their ability to bind specifically to target antigens without triggering an immune response or other effector functions associated with the Fc region.

Cytotoxicity tests, immunologic are a group of laboratory assays used to measure the immune-mediated damage or destruction (cytotoxicity) of cells. These tests are often used in medical research and clinical settings to evaluate the potential toxicity of drugs, biological agents, or environmental factors on specific types of cells.

Immunologic cytotoxicity tests typically involve the use of immune effector cells, such as cytotoxic T lymphocytes (CTLs) or natural killer (NK) cells, which can recognize and kill target cells that express specific antigens on their surface. The tests may also involve the use of antibodies or other immune molecules that can bind to target cells and trigger complement-mediated cytotoxicity.

There are several types of immunologic cytotoxicity tests, including:

1. Cytotoxic T lymphocyte (CTL) assays: These tests measure the ability of CTLs to recognize and kill target cells that express specific antigens. The test involves incubating target cells with CTLs and then measuring the amount of cell death or damage.
2. Natural killer (NK) cell assays: These tests measure the ability of NK cells to recognize and kill target cells that lack self-antigens or express stress-induced antigens. The test involves incubating target cells with NK cells and then measuring the amount of cell death or damage.
3. Antibody-dependent cellular cytotoxicity (ADCC) assays: These tests measure the ability of antibodies to bind to target cells and recruit immune effector cells, such as NK cells or macrophages, to mediate cell lysis. The test involves incubating target cells with antibodies and then measuring the amount of cell death or damage.
4. Complement-dependent cytotoxicity (CDC) assays: These tests measure the ability of complement proteins to bind to target cells and form a membrane attack complex that leads to cell lysis. The test involves incubating target cells with complement proteins and then measuring the amount of cell death or damage.

Immunologic cytotoxicity tests are important tools in immunology, cancer research, and drug development. They can help researchers understand how immune cells recognize and kill infected or damaged cells, as well as how to develop new therapies that enhance or inhibit these processes.

In a medical context, "hot temperature" is not a standard medical term with a specific definition. However, it is often used in relation to fever, which is a common symptom of illness. A fever is typically defined as a body temperature that is higher than normal, usually above 38°C (100.4°F) for adults and above 37.5-38°C (99.5-101.3°F) for children, depending on the source.

Therefore, when a medical professional talks about "hot temperature," they may be referring to a body temperature that is higher than normal due to fever or other causes. It's important to note that a high environmental temperature can also contribute to an elevated body temperature, so it's essential to consider both the body temperature and the environmental temperature when assessing a patient's condition.

Lymphocytes are a type of white blood cell that is an essential part of the immune system. They are responsible for recognizing and responding to potentially harmful substances such as viruses, bacteria, and other foreign invaders. There are two main types of lymphocytes: B-lymphocytes (B-cells) and T-lymphocytes (T-cells).

B-lymphocytes produce antibodies, which are proteins that help to neutralize or destroy foreign substances. When a B-cell encounters a foreign substance, it becomes activated and begins to divide and differentiate into plasma cells, which produce and secrete large amounts of antibodies. These antibodies bind to the foreign substance, marking it for destruction by other immune cells.

T-lymphocytes, on the other hand, are involved in cell-mediated immunity. They directly attack and destroy infected cells or cancerous cells. T-cells can also help to regulate the immune response by producing chemical signals that activate or inhibit other immune cells.

Lymphocytes are produced in the bone marrow and mature in either the bone marrow (B-cells) or the thymus gland (T-cells). They circulate throughout the body in the blood and lymphatic system, where they can be found in high concentrations in lymph nodes, the spleen, and other lymphoid organs.

Abnormalities in the number or function of lymphocytes can lead to a variety of immune-related disorders, including immunodeficiency diseases, autoimmune disorders, and cancer.

Viral proteins are the proteins that are encoded by the viral genome and are essential for the viral life cycle. These proteins can be structural or non-structural and play various roles in the virus's replication, infection, and assembly process. Structural proteins make up the physical structure of the virus, including the capsid (the protein shell that surrounds the viral genome) and any envelope proteins (that may be present on enveloped viruses). Non-structural proteins are involved in the replication of the viral genome and modulation of the host cell environment to favor viral replication. Overall, a thorough understanding of viral proteins is crucial for developing antiviral therapies and vaccines.

Blood is the fluid that circulates in the body of living organisms, carrying oxygen and nutrients to the cells and removing carbon dioxide and other waste products. It is composed of red and white blood cells suspended in a liquid called plasma. The main function of blood is to transport oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs. It also transports nutrients, hormones, and other substances to the cells and removes waste products from them. Additionally, blood plays a crucial role in the body's immune system by helping to fight infection and disease.

Gel chromatography is a type of liquid chromatography that separates molecules based on their size or molecular weight. It uses a stationary phase that consists of a gel matrix made up of cross-linked polymers, such as dextran, agarose, or polyacrylamide. The gel matrix contains pores of various sizes, which allow smaller molecules to penetrate deeper into the matrix while larger molecules are excluded.

In gel chromatography, a mixture of molecules is loaded onto the top of the gel column and eluted with a solvent that moves down the column by gravity or pressure. As the sample components move down the column, they interact with the gel matrix and get separated based on their size. Smaller molecules can enter the pores of the gel and take longer to elute, while larger molecules are excluded from the pores and elute more quickly.

Gel chromatography is commonly used to separate and purify proteins, nucleic acids, and other biomolecules based on their size and molecular weight. It is also used in the analysis of polymers, colloids, and other materials with a wide range of applications in chemistry, biology, and medicine.

Solubility is a fundamental concept in pharmaceutical sciences and medicine, which refers to the maximum amount of a substance (solute) that can be dissolved in a given quantity of solvent (usually water) at a specific temperature and pressure. Solubility is typically expressed as mass of solute per volume or mass of solvent (e.g., grams per liter, milligrams per milliliter). The process of dissolving a solute in a solvent results in a homogeneous solution where the solute particles are dispersed uniformly throughout the solvent.

Understanding the solubility of drugs is crucial for their formulation, administration, and therapeutic effectiveness. Drugs with low solubility may not dissolve sufficiently to produce the desired pharmacological effect, while those with high solubility might lead to rapid absorption and short duration of action. Therefore, optimizing drug solubility through various techniques like particle size reduction, salt formation, or solubilization is an essential aspect of drug development and delivery.

Beta-Aminoethyl Isothiourea is not a medical term, but a chemical compound. Its systematic name is (betaine) N-(β-aminoethyl)-isothiouronium bromide. It is used in research and pharmaceutical industry as a tool for studying various biochemical processes, particularly related to enzyme inhibition.

It acts as a potent and irreversible inhibitor of several enzymes such as carboxylesterases, cholinesterases, and proteases. It is not used in clinical medicine or approved for human use.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Signal transduction is the process by which a cell converts an extracellular signal, such as a hormone or neurotransmitter, into an intracellular response. This involves a series of molecular events that transmit the signal from the cell surface to the interior of the cell, ultimately resulting in changes in gene expression, protein activity, or metabolism.

The process typically begins with the binding of the extracellular signal to a receptor located on the cell membrane. This binding event activates the receptor, which then triggers a cascade of intracellular signaling molecules, such as second messengers, protein kinases, and ion channels. These molecules amplify and propagate the signal, ultimately leading to the activation or inhibition of specific cellular responses.

Signal transduction pathways are highly regulated and can be modulated by various factors, including other signaling molecules, post-translational modifications, and feedback mechanisms. Dysregulation of these pathways has been implicated in a variety of diseases, including cancer, diabetes, and neurological disorders.

Sequence homology in nucleic acids refers to the similarity or identity between the nucleotide sequences of two or more DNA or RNA molecules. It is often used as a measure of biological relationship between genes, organisms, or populations. High sequence homology suggests a recent common ancestry or functional constraint, while low sequence homology may indicate a more distant relationship or different functions.

Nucleic acid sequence homology can be determined by various methods such as pairwise alignment, multiple sequence alignment, and statistical analysis. The degree of homology is typically expressed as a percentage of identical or similar nucleotides in a given window of comparison.

It's important to note that the interpretation of sequence homology depends on the biological context and the evolutionary distance between the sequences compared. Therefore, functional and experimental validation is often necessary to confirm the significance of sequence homology.

The retinal pigment epithelium (RPE) is a single layer of cells located between the photoreceptor cells of the retina and the choroid, which is a part of the eye containing blood vessels. The RPE plays a crucial role in maintaining the health and function of the photoreceptors by providing them with nutrients, removing waste products, and helping to regulate the light-sensitive visual pigments within the photoreceptors.

The RPE cells contain pigment granules that absorb excess light to prevent scattering within the eye and improve visual acuity. They also help to form the blood-retina barrier, which restricts the movement of certain molecules between the retina and the choroid, providing an important protective function for the retina.

Damage to the RPE can lead to a variety of eye conditions, including age-related macular degeneration (AMD), which is a leading cause of vision loss in older adults.

Graft rejection is an immune response that occurs when transplanted tissue or organ (the graft) is recognized as foreign by the recipient's immune system, leading to the activation of immune cells to attack and destroy the graft. This results in the failure of the transplant and the need for additional medical intervention or another transplant. There are three types of graft rejection: hyperacute, acute, and chronic. Hyperacute rejection occurs immediately or soon after transplantation due to pre-existing antibodies against the graft. Acute rejection typically occurs within weeks to months post-transplant and is characterized by the infiltration of T-cells into the graft. Chronic rejection, which can occur months to years after transplantation, is a slow and progressive process characterized by fibrosis and tissue damage due to ongoing immune responses against the graft.

Heparin is defined as a highly sulfated glycosaminoglycan (a type of polysaccharide) that is widely present in many tissues, but is most commonly derived from the mucosal tissues of mammalian lungs or intestinal mucosa. It is an anticoagulant that acts as an inhibitor of several enzymes involved in the blood coagulation cascade, primarily by activating antithrombin III which then neutralizes thrombin and other clotting factors.

Heparin is used medically to prevent and treat thromboembolic disorders such as deep vein thrombosis, pulmonary embolism, and certain types of heart attacks. It can also be used during hemodialysis, cardiac bypass surgery, and other medical procedures to prevent the formation of blood clots.

It's important to note that while heparin is a powerful anticoagulant, it does not have any fibrinolytic activity, meaning it cannot dissolve existing blood clots. Instead, it prevents new clots from forming and stops existing clots from growing larger.

Macromolecular substances, also known as macromolecules, are large, complex molecules made up of repeating subunits called monomers. These substances are formed through polymerization, a process in which many small molecules combine to form a larger one. Macromolecular substances can be naturally occurring, such as proteins, DNA, and carbohydrates, or synthetic, such as plastics and synthetic fibers.

In the context of medicine, macromolecular substances are often used in the development of drugs and medical devices. For example, some drugs are designed to bind to specific macromolecules in the body, such as proteins or DNA, in order to alter their function and produce a therapeutic effect. Additionally, macromolecular substances may be used in the creation of medical implants, such as artificial joints and heart valves, due to their strength and durability.

It is important for healthcare professionals to have an understanding of macromolecular substances and how they function in the body, as this knowledge can inform the development and use of medical treatments.

Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) is a laboratory technique used in molecular biology to amplify and detect specific DNA sequences. This technique is particularly useful for the detection and quantification of RNA viruses, as well as for the analysis of gene expression.

The process involves two main steps: reverse transcription and polymerase chain reaction (PCR). In the first step, reverse transcriptase enzyme is used to convert RNA into complementary DNA (cDNA) by reading the template provided by the RNA molecule. This cDNA then serves as a template for the PCR amplification step.

In the second step, the PCR reaction uses two primers that flank the target DNA sequence and a thermostable polymerase enzyme to repeatedly copy the targeted cDNA sequence. The reaction mixture is heated and cooled in cycles, allowing the primers to anneal to the template, and the polymerase to extend the new strand. This results in exponential amplification of the target DNA sequence, making it possible to detect even small amounts of RNA or cDNA.

RT-PCR is a sensitive and specific technique that has many applications in medical research and diagnostics, including the detection of viruses such as HIV, hepatitis C virus, and SARS-CoV-2 (the virus that causes COVID-19). It can also be used to study gene expression, identify genetic mutations, and diagnose genetic disorders.

Thrombotic microangiopathies (TMAs) are a group of disorders characterized by the formation of blood clots in small blood vessels, causing damage to the end organs. This process leads to a constellation of clinical symptoms including thrombocytopenia (low platelet count), microangiopathic hemolytic anemia (breakdown of red blood cells leading to anemia), and organ dysfunction such as renal failure, neurological impairment, or cardiac involvement.

TMAs can be primary or secondary. Primary TMAs are caused by genetic mutations affecting the complement system, coagulation cascade, or other regulatory proteins involved in vascular homeostasis. Examples of primary TMAs include atypical hemolytic uremic syndrome (aHUS), thrombotic thrombocytopenic purpura (TTP), and complement-mediated TMA.

Secondary TMAs are caused by various underlying conditions or exposures, such as infections, autoimmune diseases, malignancies, drugs, pregnancy-related complications, or other systemic disorders. The pathogenesis of secondary TMAs is often multifactorial and may involve endothelial injury, complement activation, and platelet aggregation.

The diagnosis of TMAs requires a combination of clinical, laboratory, and sometimes histopathological findings. Treatment depends on the underlying cause and may include supportive care, plasma exchange, immunosuppressive therapy, or targeted therapies such as complement inhibitors.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

Sepsis is a life-threatening condition that arises when the body's response to an infection injures its own tissues and organs. It is characterized by a whole-body inflammatory state (systemic inflammation) that can lead to blood clotting issues, tissue damage, and multiple organ failure.

Sepsis happens when an infection you already have triggers a chain reaction throughout your body. Infections that lead to sepsis most often start in the lungs, urinary tract, skin, or gastrointestinal tract.

Sepsis is a medical emergency. If you suspect sepsis, seek immediate medical attention. Early recognition and treatment of sepsis are crucial to improve outcomes. Treatment usually involves antibiotics, intravenous fluids, and may require oxygen, medication to raise blood pressure, and corticosteroids. In severe cases, surgery may be required to clear the infection.

Trypsin is a proteolytic enzyme, specifically a serine protease, that is secreted by the pancreas as an inactive precursor, trypsinogen. Trypsinogen is converted into its active form, trypsin, in the small intestine by enterokinase, which is produced by the intestinal mucosa.

Trypsin plays a crucial role in digestion by cleaving proteins into smaller peptides at specific arginine and lysine residues. This enzyme helps to break down dietary proteins into amino acids, allowing for their absorption and utilization by the body. Additionally, trypsin can activate other zymogenic pancreatic enzymes, such as chymotrypsinogen and procarboxypeptidases, thereby contributing to overall protein digestion.

Cross reactions, in the context of medical diagnostics and immunology, refer to a situation where an antibody or a immune response directed against one antigen also reacts with a different antigen due to similarities in their molecular structure. This can occur in allergy testing, where a person who is allergic to a particular substance may have a positive test result for a different but related substance because of cross-reactivity between them. For example, some individuals who are allergic to birch pollen may also have symptoms when eating certain fruits, such as apples, due to cross-reactive proteins present in both.

'Borrelia burgdorferi' is a species of spirochete bacteria that is the primary cause of Lyme disease in humans. The bacteria are transmitted to humans through the bite of infected black-legged ticks (Ixodes scapularis in the northeastern, midwestern, and eastern parts of the United States; Ixodes pacificus on the Pacific Coast).

The bacterium was first identified and named after Willy Burgdorfer, who discovered the spirochete in the mid-1980s. The infection can lead to a variety of symptoms, including fever, headache, fatigue, and a characteristic skin rash called erythema migrans. If left untreated, the infection can spread to joints, the heart, and the nervous system, leading to more severe complications.

Antibiotic treatment is usually effective in eliminating the bacteria and resolving symptoms, especially when initiated early in the course of the disease. However, some individuals may experience persistent symptoms even after treatment, a condition known as post-treatment Lyme disease syndrome (PTLDS). The exact cause of PTLDS remains unclear, with ongoing research investigating potential factors such as residual bacterial infection, autoimmune responses, or tissue damage.

Immunoenzyme techniques are a group of laboratory methods used in immunology and clinical chemistry that combine the specificity of antibody-antigen reactions with the sensitivity and amplification capabilities of enzyme reactions. These techniques are primarily used for the detection, quantitation, or identification of various analytes (such as proteins, hormones, drugs, viruses, or bacteria) in biological samples.

In immunoenzyme techniques, an enzyme is linked to an antibody or antigen, creating a conjugate. This conjugate then interacts with the target analyte in the sample, forming an immune complex. The presence and amount of this immune complex can be visualized or measured by detecting the enzymatic activity associated with it.

There are several types of immunoenzyme techniques, including:

1. Enzyme-linked Immunosorbent Assay (ELISA): A widely used method for detecting and quantifying various analytes in a sample. In ELISA, an enzyme is attached to either the capture antibody or the detection antibody. After the immune complex formation, a substrate is added that reacts with the enzyme, producing a colored product that can be measured spectrophotometrically.
2. Immunoblotting (Western blot): A method used for detecting specific proteins in a complex mixture, such as a protein extract from cells or tissues. In this technique, proteins are separated by gel electrophoresis and transferred to a membrane, where they are probed with an enzyme-conjugated antibody directed against the target protein.
3. Immunohistochemistry (IHC): A method used for detecting specific antigens in tissue sections or cells. In IHC, an enzyme-conjugated primary or secondary antibody is applied to the sample, and the presence of the antigen is visualized using a chromogenic substrate that produces a colored product at the site of the antigen-antibody interaction.
4. Immunofluorescence (IF): A method used for detecting specific antigens in cells or tissues by employing fluorophore-conjugated antibodies. The presence of the antigen is visualized using a fluorescence microscope.
5. Enzyme-linked immunosorbent assay (ELISA): A method used for detecting and quantifying specific antigens or antibodies in liquid samples, such as serum or culture supernatants. In ELISA, an enzyme-conjugated detection antibody is added after the immune complex formation, and a substrate is added that reacts with the enzyme to produce a colored product that can be measured spectrophotometrically.

These techniques are widely used in research and diagnostic laboratories for various applications, including protein characterization, disease diagnosis, and monitoring treatment responses.

Staphylococcus aureus is a type of gram-positive, round (coccal) bacterium that is commonly found on the skin and mucous membranes of warm-blooded animals and humans. It is a facultative anaerobe, which means it can grow in the presence or absence of oxygen.

Staphylococcus aureus is known to cause a wide range of infections, from mild skin infections such as pimples, impetigo, and furuncles (boils) to more severe and potentially life-threatening infections such as pneumonia, endocarditis, osteomyelitis, and sepsis. It can also cause food poisoning and toxic shock syndrome.

The bacterium is often resistant to multiple antibiotics, including methicillin, which has led to the emergence of methicillin-resistant Staphylococcus aureus (MRSA) strains that are difficult to treat. Proper hand hygiene and infection control practices are critical in preventing the spread of Staphylococcus aureus and MRSA.

Vitronectin is a glycoprotein found in various biological fluids, including blood plasma. It has multiple functions in the body, such as participating in blood clotting (as a cofactor for the protease thrombin), inhibiting the complement system, and binding to cell surfaces and the extracellular matrix. Vitronectin can also interact with several other molecules, including heparin, collagen, and the cytoskeleton. It is involved in various biological processes, such as cell adhesion, migration, and protection against apoptosis (programmed cell death).

Virulence, in the context of medicine and microbiology, refers to the degree or severity of damage or harm that a pathogen (like a bacterium, virus, fungus, or parasite) can cause to its host. It is often associated with the ability of the pathogen to invade and damage host tissues, evade or suppress the host's immune response, replicate within the host, and spread between hosts.

Virulence factors are the specific components or mechanisms that contribute to a pathogen's virulence, such as toxins, enzymes, adhesins, and capsules. These factors enable the pathogen to establish an infection, cause tissue damage, and facilitate its transmission between hosts. The overall virulence of a pathogen can be influenced by various factors, including host susceptibility, environmental conditions, and the specific strain or species of the pathogen.

Serum Amyloid P-component (SAP) is a protein that is normally present in the blood and other bodily fluids. It is a part of the larger family of pentraxin proteins, which are involved in the innate immune response, meaning they provide immediate defense against foreign invaders without needing to adapt over time. SAP plays a role in inflammation, immune complex clearance, and complement activation.

In the context of amyloidosis, SAP binds to misfolded proteins called amyloid fibrils, which can deposit in various tissues and organs, leading to their dysfunction and failure. The accumulation of these amyloid fibrils with SAP is a hallmark of systemic amyloidosis.

It's important to note that while SAP plays a role in the pathogenesis of amyloidosis, it is not directly responsible for causing the disease. Instead, its presence can serve as a useful marker for diagnosing and monitoring the progression of amyloidosis.

Heterophile antibodies are a type of antibody that can react with antigens from more than one source, rather than being specific to a single antigen. They are produced in response to an initial infection or immunization, but can also cross-react with antigens from unrelated organisms or substances. A common example of heterophile antibodies are those that are produced in response to Epstein-Barr virus (EBV) infection, which can cause infectious mononucleosis. These antibodies, known as Paul-Bunnell antibodies, can agglutinate (clump together) sheep or horse red blood cells, which is the basis for a diagnostic test for EBV infection called the Monospot test. However, it's important to note that not all cases of infectious mononucleosis are caused by EBV, and other infections or conditions can also cause the production of heterophile antibodies, leading to false-positive results.

Trypanosoma lewisi is a species of protozoan parasites belonging to the family Trypanosomatidae. It is primarily found in rats and is transmitted through the bite of fleas. This parasite typically infects the erythrocytes (red blood cells) of rats, causing a benign infection known as "rat trypanosomiasis" or "lewisi disease."

In a medical context, Trypanosoma lewisi is not considered a significant pathogen for humans. However, rare cases of human infections have been reported, usually due to accidental laboratory exposure or through the consumption of contaminated water or food. In these instances, the infection typically resolves on its own without causing severe symptoms or complications.

It's worth noting that Trypanosoma lewisi is often used as a model organism in scientific research related to trypanosomatid biology and parasitology due to its relatively simple life cycle and ease of cultivation in the laboratory.

"Cricetulus" is a genus of rodents that includes several species of hamsters. These small, burrowing animals are native to Asia and have a body length of about 8-15 centimeters, with a tail that is usually shorter than the body. They are characterized by their large cheek pouches, which they use to store food. Some common species in this genus include the Chinese hamster (Cricetulus griseus) and the Daurian hamster (Cricetulus dauuricus). These animals are often kept as pets or used in laboratory research.

Biological models, also known as physiological models or organismal models, are simplified representations of biological systems, processes, or mechanisms that are used to understand and explain the underlying principles and relationships. These models can be theoretical (conceptual or mathematical) or physical (such as anatomical models, cell cultures, or animal models). They are widely used in biomedical research to study various phenomena, including disease pathophysiology, drug action, and therapeutic interventions.

Examples of biological models include:

1. Mathematical models: These use mathematical equations and formulas to describe complex biological systems or processes, such as population dynamics, metabolic pathways, or gene regulation networks. They can help predict the behavior of these systems under different conditions and test hypotheses about their underlying mechanisms.
2. Cell cultures: These are collections of cells grown in a controlled environment, typically in a laboratory dish or flask. They can be used to study cellular processes, such as signal transduction, gene expression, or metabolism, and to test the effects of drugs or other treatments on these processes.
3. Animal models: These are living organisms, usually vertebrates like mice, rats, or non-human primates, that are used to study various aspects of human biology and disease. They can provide valuable insights into the pathophysiology of diseases, the mechanisms of drug action, and the safety and efficacy of new therapies.
4. Anatomical models: These are physical representations of biological structures or systems, such as plastic models of organs or tissues, that can be used for educational purposes or to plan surgical procedures. They can also serve as a basis for developing more sophisticated models, such as computer simulations or 3D-printed replicas.

Overall, biological models play a crucial role in advancing our understanding of biology and medicine, helping to identify new targets for therapeutic intervention, develop novel drugs and treatments, and improve human health.

Bovine Serum Albumin (BSA) is not a medical term per se, but a biochemical term. It is widely used in medical and biological research. Here's the definition:

Bovine Serum Albumin is a serum albumin protein derived from cows. It is often used as a stabilizer, an emulsifier, or a protein source in various laboratory and industrial applications, including biochemical experiments, cell culture media, and diagnostic kits. BSA has a high solubility in water and can bind to many different types of molecules, making it useful for preventing unwanted interactions between components in a solution. It also has a consistent composition and is relatively inexpensive compared to human serum albumin, which are factors that contribute to its widespread use.

Fungal proteins are a type of protein that is specifically produced and present in fungi, which are a group of eukaryotic organisms that include microorganisms such as yeasts and molds. These proteins play various roles in the growth, development, and survival of fungi. They can be involved in the structure and function of fungal cells, metabolism, pathogenesis, and other cellular processes. Some fungal proteins can also have important implications for human health, both in terms of their potential use as therapeutic targets and as allergens or toxins that can cause disease.

Fungal proteins can be classified into different categories based on their functions, such as enzymes, structural proteins, signaling proteins, and toxins. Enzymes are proteins that catalyze chemical reactions in fungal cells, while structural proteins provide support and protection for the cell. Signaling proteins are involved in communication between cells and regulation of various cellular processes, and toxins are proteins that can cause harm to other organisms, including humans.

Understanding the structure and function of fungal proteins is important for developing new treatments for fungal infections, as well as for understanding the basic biology of fungi. Research on fungal proteins has led to the development of several antifungal drugs that target specific fungal enzymes or other proteins, providing effective treatment options for a range of fungal diseases. Additionally, further study of fungal proteins may reveal new targets for drug development and help improve our ability to diagnose and treat fungal infections.

Venom is a complex mixture of toxic compounds produced by certain animals, such as snakes, spiders, scorpions, and marine creatures like cone snails and stonefish. These toxic substances are specifically designed to cause damage to the tissues or interfere with the normal physiological processes of other organisms, which can lead to harmful or even lethal effects.

Venoms typically contain a variety of components, including enzymes, peptides, proteins, and small molecules, each with specific functions that contribute to the overall toxicity of the mixture. Some of these components may cause localized damage, such as tissue necrosis or inflammation, while others can have systemic effects, impacting various organs and bodily functions.

The study of venoms, known as toxinology, has important implications for understanding the evolution of animal behavior, developing new therapeutics, and advancing medical treatments for envenomation (the process of being poisoned by venom). Additionally, venoms have been used in traditional medicine for centuries, and ongoing research continues to uncover novel compounds with potential applications in modern pharmacology.

Immunologic deficiency syndromes refer to a group of disorders characterized by defective functioning of the immune system, leading to increased susceptibility to infections and malignancies. These deficiencies can be primary (genetic or congenital) or secondary (acquired due to environmental factors, medications, or diseases).

Primary immunodeficiency syndromes (PIDS) are caused by inherited genetic mutations that affect the development and function of immune cells, such as T cells, B cells, and phagocytes. Examples include severe combined immunodeficiency (SCID), common variable immunodeficiency (CVID), Wiskott-Aldrich syndrome, and X-linked agammaglobulinemia.

Secondary immunodeficiency syndromes can result from various factors, including:

1. HIV/AIDS: Human Immunodeficiency Virus infection leads to the depletion of CD4+ T cells, causing profound immune dysfunction and increased vulnerability to opportunistic infections and malignancies.
2. Medications: Certain medications, such as chemotherapy, immunosuppressive drugs, and long-term corticosteroid use, can impair immune function and increase infection risk.
3. Malnutrition: Deficiencies in essential nutrients like protein, vitamins, and minerals can weaken the immune system and make individuals more susceptible to infections.
4. Aging: The immune system naturally declines with age, leading to an increased incidence of infections and poorer vaccine responses in older adults.
5. Other medical conditions: Chronic diseases such as diabetes, cancer, and chronic kidney or liver disease can also compromise the immune system and contribute to immunodeficiency syndromes.

Immunologic deficiency syndromes require appropriate diagnosis and management strategies, which may include antimicrobial therapy, immunoglobulin replacement, hematopoietic stem cell transplantation, or targeted treatments for the underlying cause.

A multigene family is a group of genetically related genes that share a common ancestry and have similar sequences or structures. These genes are arranged in clusters on a chromosome and often encode proteins with similar functions. They can arise through various mechanisms, including gene duplication, recombination, and transposition. Multigene families play crucial roles in many biological processes, such as development, immunity, and metabolism. Examples of multigene families include the globin genes involved in oxygen transport, the immune system's major histocompatibility complex (MHC) genes, and the cytochrome P450 genes associated with drug metabolism.

Site-directed mutagenesis is a molecular biology technique used to introduce specific and targeted changes to a specific DNA sequence. This process involves creating a new variant of a gene or a specific region of interest within a DNA molecule by introducing a planned, deliberate change, or mutation, at a predetermined site within the DNA sequence.

The methodology typically involves the use of molecular tools such as PCR (polymerase chain reaction), restriction enzymes, and/or ligases to introduce the desired mutation(s) into a plasmid or other vector containing the target DNA sequence. The resulting modified DNA molecule can then be used to transform host cells, allowing for the production of large quantities of the mutated gene or protein for further study.

Site-directed mutagenesis is a valuable tool in basic research, drug discovery, and biotechnology applications where specific changes to a DNA sequence are required to understand gene function, investigate protein structure/function relationships, or engineer novel biological properties into existing genes or proteins.

Polysaccharides are complex carbohydrates consisting of long chains of monosaccharide units (simple sugars) bonded together by glycosidic linkages. They can be classified based on the type of monosaccharides and the nature of the bonds that connect them.

Polysaccharides have various functions in living organisms. For example, starch and glycogen serve as energy storage molecules in plants and animals, respectively. Cellulose provides structural support in plants, while chitin is a key component of fungal cell walls and arthropod exoskeletons.

Some polysaccharides also have important roles in the human body, such as being part of the extracellular matrix (e.g., hyaluronic acid) or acting as blood group antigens (e.g., ABO blood group substances).

Anti-idiotypic antibodies are a type of immune protein that recognizes and binds to the unique identifying region (idiotype) of another antibody. These antibodies are produced by the immune system as part of a regulatory feedback mechanism, where they can modulate or inhibit the activity of the original antibody. They have been studied for their potential use in immunotherapy and vaccine development.

Genetic transcription is the process by which the information in a strand of DNA is used to create a complementary RNA molecule. This process is the first step in gene expression, where the genetic code in DNA is converted into a form that can be used to produce proteins or functional RNAs.

During transcription, an enzyme called RNA polymerase binds to the DNA template strand and reads the sequence of nucleotide bases. As it moves along the template, it adds complementary RNA nucleotides to the growing RNA chain, creating a single-stranded RNA molecule that is complementary to the DNA template strand. Once transcription is complete, the RNA molecule may undergo further processing before it can be translated into protein or perform its functional role in the cell.

Transcription can be either "constitutive" or "regulated." Constitutive transcription occurs at a relatively constant rate and produces essential proteins that are required for basic cellular functions. Regulated transcription, on the other hand, is subject to control by various intracellular and extracellular signals, allowing cells to respond to changing environmental conditions or developmental cues.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

Granulocytes are a type of white blood cell that plays a crucial role in the body's immune system. They are called granulocytes because they contain small granules in their cytoplasm, which are filled with various enzymes and proteins that help them fight off infections and destroy foreign substances.

There are three types of granulocytes: neutrophils, eosinophils, and basophils. Neutrophils are the most abundant type and are primarily responsible for fighting bacterial infections. Eosinophils play a role in defending against parasitic infections and regulating immune responses. Basophils are involved in inflammatory reactions and allergic responses.

Granulocytes are produced in the bone marrow and released into the bloodstream, where they circulate and patrol for any signs of infection or foreign substances. When they encounter a threat, they quickly move to the site of infection or injury and release their granules to destroy the invading organisms or substances.

Abnormal levels of granulocytes in the blood can indicate an underlying medical condition, such as an infection, inflammation, or a bone marrow disorder.

Mutagenesis is the process by which the genetic material (DNA or RNA) of an organism is changed in a way that can alter its phenotype, or observable traits. These changes, known as mutations, can be caused by various factors such as chemicals, radiation, or viruses. Some mutations may have no effect on the organism, while others can cause harm, including diseases and cancer. Mutagenesis is a crucial area of study in genetics and molecular biology, with implications for understanding evolution, genetic disorders, and the development of new medical treatments.

Cyclic peptides are a type of peptides in which the N-terminus and C-terminus of the peptide chain are linked to form a circular structure. This is in contrast to linear peptides, which have a straight peptide backbone with a free N-terminus and C-terminus. The cyclization of peptides can occur through various mechanisms, including the formation of an amide bond between the N-terminal amino group and the C-terminal carboxylic acid group (head-to-tail cyclization), or through the formation of a bond between side chain functional groups.

Cyclic peptides have unique structural and chemical properties that make them valuable in medical and therapeutic applications. For example, they are more resistant to degradation by enzymes compared to linear peptides, which can increase their stability and half-life in the body. Additionally, the cyclic structure allows for greater conformational rigidity, which can enhance their binding affinity and specificity to target molecules.

Cyclic peptides have been explored as potential therapeutics for a variety of diseases, including cancer, infectious diseases, and neurological disorders. They have also been used as tools in basic research to study protein-protein interactions and cell signaling pathways.

Chemotactic factors are substances that attract or repel cells, particularly immune cells, by stimulating directional movement in response to a chemical gradient. These factors play a crucial role in the body's immune response and inflammation process. They include:

1. Chemokines: A family of small signaling proteins that direct the migration of immune cells to sites of infection or tissue damage.
2. Cytokines: A broad category of signaling molecules that mediate and regulate immunity, inflammation, and hematopoiesis. Some cytokines can also act as chemotactic factors.
3. Complement components: Cleavage products of the complement system can attract immune cells to the site of infection or tissue injury.
4. Growth factors: Certain growth factors, like colony-stimulating factors (CSFs), can stimulate the migration and proliferation of specific cell types.
5. Lipid mediators: Products derived from arachidonic acid metabolism, such as leukotrienes and prostaglandins, can also act as chemotactic factors.
6. Formyl peptides: Bacterial-derived formylated peptides can attract and activate neutrophils during an infection.
7. Extracellular matrix (ECM) components: Fragments of ECM proteins, like collagen and fibronectin, can serve as chemotactic factors for immune cells.

These factors help orchestrate the immune response by guiding the movement of immune cells to specific locations in the body where they are needed.

A biological marker, often referred to as a biomarker, is a measurable indicator that reflects the presence or severity of a disease state, or a response to a therapeutic intervention. Biomarkers can be found in various materials such as blood, tissues, or bodily fluids, and they can take many forms, including molecular, histologic, radiographic, or physiological measurements.

In the context of medical research and clinical practice, biomarkers are used for a variety of purposes, such as:

1. Diagnosis: Biomarkers can help diagnose a disease by indicating the presence or absence of a particular condition. For example, prostate-specific antigen (PSA) is a biomarker used to detect prostate cancer.
2. Monitoring: Biomarkers can be used to monitor the progression or regression of a disease over time. For instance, hemoglobin A1c (HbA1c) levels are monitored in diabetes patients to assess long-term blood glucose control.
3. Predicting: Biomarkers can help predict the likelihood of developing a particular disease or the risk of a negative outcome. For example, the presence of certain genetic mutations can indicate an increased risk for breast cancer.
4. Response to treatment: Biomarkers can be used to evaluate the effectiveness of a specific treatment by measuring changes in the biomarker levels before and after the intervention. This is particularly useful in personalized medicine, where treatments are tailored to individual patients based on their unique biomarker profiles.

It's important to note that for a biomarker to be considered clinically valid and useful, it must undergo rigorous validation through well-designed studies, including demonstrating sensitivity, specificity, reproducibility, and clinical relevance.

"Competitive binding" is a term used in pharmacology and biochemistry to describe the behavior of two or more molecules (ligands) competing for the same binding site on a target protein or receptor. In this context, "binding" refers to the physical interaction between a ligand and its target.

When a ligand binds to a receptor, it can alter the receptor's function, either activating or inhibiting it. If multiple ligands compete for the same binding site, they will compete to bind to the receptor. The ability of each ligand to bind to the receptor is influenced by its affinity for the receptor, which is a measure of how strongly and specifically the ligand binds to the receptor.

In competitive binding, if one ligand is present in high concentrations, it can prevent other ligands with lower affinity from binding to the receptor. This is because the higher-affinity ligand will have a greater probability of occupying the binding site and blocking access to the other ligands. The competition between ligands can be described mathematically using equations such as the Langmuir isotherm, which describes the relationship between the concentration of ligand and the fraction of receptors that are occupied by the ligand.

Competitive binding is an important concept in drug development, as it can be used to predict how different drugs will interact with their targets and how they may affect each other's activity. By understanding the competitive binding properties of a drug, researchers can optimize its dosage and delivery to maximize its therapeutic effect while minimizing unwanted side effects.

Cytokines are a broad and diverse category of small signaling proteins that are secreted by various cells, including immune cells, in response to different stimuli. They play crucial roles in regulating the immune response, inflammation, hematopoiesis, and cellular communication.

Cytokines mediate their effects by binding to specific receptors on the surface of target cells, which triggers intracellular signaling pathways that ultimately result in changes in gene expression, cell behavior, and function. Some key functions of cytokines include:

1. Regulating the activation, differentiation, and proliferation of immune cells such as T cells, B cells, natural killer (NK) cells, and macrophages.
2. Coordinating the inflammatory response by recruiting immune cells to sites of infection or tissue damage and modulating their effector functions.
3. Regulating hematopoiesis, the process of blood cell formation in the bone marrow, by controlling the proliferation, differentiation, and survival of hematopoietic stem and progenitor cells.
4. Modulating the development and function of the nervous system, including neuroinflammation, neuroprotection, and neuroregeneration.

Cytokines can be classified into several categories based on their structure, function, or cellular origin. Some common types of cytokines include interleukins (ILs), interferons (IFNs), tumor necrosis factors (TNFs), chemokines, colony-stimulating factors (CSFs), and transforming growth factors (TGFs). Dysregulation of cytokine production and signaling has been implicated in various pathological conditions, such as autoimmune diseases, chronic inflammation, cancer, and neurodegenerative disorders.

Serum sickness is an immune-mediated hypersensitivity reaction that typically occurs within 1 to 3 weeks after the administration of foreign proteins or drugs, such as certain types of antibiotics, antiserums, or monoclonal antibodies. It is characterized by symptoms such as fever, rash, joint pain, and lymphadenopathy (swollen lymph nodes). These symptoms are caused by the formation of immune complexes, which deposit in various tissues and activate the complement system, leading to inflammation. Serum sickness can be treated with antihistamines, corticosteroids, and other immunomodulatory agents. It is important to note that serum sickness is different from anaphylaxis, which is a more severe, life-threatening allergic reaction that occurs immediately after exposure to an allergen.

Esterases are a group of enzymes that catalyze the hydrolysis of ester bonds in esters, producing alcohols and carboxylic acids. They are widely distributed in plants, animals, and microorganisms and play important roles in various biological processes, such as metabolism, digestion, and detoxification.

Esterases can be classified into several types based on their substrate specificity, including carboxylesterases, cholinesterases, lipases, and phosphatases. These enzymes have different structures and mechanisms of action but all share the ability to hydrolyze esters.

Carboxylesterases are the most abundant and diverse group of esterases, with a wide range of substrate specificity. They play important roles in the metabolism of drugs, xenobiotics, and lipids. Cholinesterases, on the other hand, specifically hydrolyze choline esters, such as acetylcholine, which is an important neurotransmitter in the nervous system. Lipases are a type of esterase that preferentially hydrolyzes triglycerides and plays a crucial role in fat digestion and metabolism. Phosphatases are enzymes that remove phosphate groups from various molecules, including esters, and have important functions in signal transduction and other cellular processes.

Esterases can also be used in industrial applications, such as in the production of biodiesel, detergents, and food additives. They are often produced by microbial fermentation or extracted from plants and animals. The use of esterases in biotechnology is an active area of research, with potential applications in biofuel production, bioremediation, and medical diagnostics.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that primarily affects the joints. It is characterized by persistent inflammation, synovial hyperplasia, and subsequent damage to the articular cartilage and bone. The immune system mistakenly attacks the body's own tissues, specifically targeting the synovial membrane lining the joint capsule. This results in swelling, pain, warmth, and stiffness in affected joints, often most severely in the hands and feet.

RA can also have extra-articular manifestations, affecting other organs such as the lungs, heart, skin, eyes, and blood vessels. The exact cause of RA remains unknown, but it is believed to involve a complex interplay between genetic susceptibility and environmental triggers. Early diagnosis and treatment are crucial in managing rheumatoid arthritis to prevent joint damage, disability, and systemic complications.

Lysine carboxypeptidase is not a widely recognized or used medical term. However, in biochemistry, carboxypeptidases are enzymes that cleave peptide bonds at the carboxyl-terminal end of a protein or peptide. If there is a specific enzyme named "lysine carboxypeptidase," it would be an enzyme that selectively removes lysine residues from the carboxyl terminus of a protein or peptide.

There are several enzymes that can act as carboxypeptidases, and some of them have specificities for certain amino acids, such as arginine or lysine. These enzymes play important roles in various biological processes, including protein degradation, processing, and regulation.

It's worth noting that the term "lysine carboxypeptidase" may refer to different enzymes depending on the context, such as bacterial or mammalian enzymes, and they may have different properties and functions.

Agglutinins are antibodies that cause the particles (such as red blood cells, bacteria, or viruses) to clump together. They recognize and bind to specific antigens on the surface of these particles, forming a bridge between them and causing them to agglutinate or clump. Agglutinins are an important part of the immune system's response to infection and help to eliminate pathogens from the body.

There are two main types of agglutinins:

1. Naturally occurring agglutinins: These are present in the blood serum of most individuals, even before exposure to an antigen. They can agglutinate some bacteria and red blood cells without prior sensitization. For example, anti-A and anti-B agglutinins are naturally occurring antibodies found in people with different blood groups (A, B, AB, or O).
2. Immune agglutinins: These are produced by the immune system after exposure to an antigen. They develop as part of the adaptive immune response and target specific antigens that the body has encountered before. Immunization with vaccines often leads to the production of immune agglutinins, which can provide protection against future infections.

Agglutination reactions are widely used in laboratory tests for various diagnostic purposes, such as blood typing, detecting bacterial or viral infections, and monitoring immune responses.

Respiratory burst is a term used in the field of biology, particularly in the context of immunology and cellular processes. It does not have a direct application to clinical medicine, but it is important for understanding certain physiological and pathophysiological mechanisms. Here's a definition of respiratory burst:

Respiratory burst is a rapid increase in oxygen consumption by phagocytic cells (like neutrophils, monocytes, and macrophages) following their activation in response to various stimuli, such as pathogens or inflammatory molecules. This process is part of the innate immune response and serves to eliminate invading microorganisms.

The respiratory burst involves the activation of NADPH oxidase, an enzyme complex present in the membrane of phagosomes (the compartment where pathogens are engulfed). Upon activation, NADPH oxidase catalyzes the reduction of oxygen to superoxide radicals, which then dismutate to form hydrogen peroxide. These reactive oxygen species (ROS) can directly kill or damage microorganisms and also serve as signaling molecules for other immune cells.

While respiratory burst is a crucial part of the immune response, excessive or dysregulated ROS production can contribute to tissue damage and chronic inflammation, which have implications in various pathological conditions, such as atherosclerosis, neurodegenerative diseases, and cancer.

Bacterial capsules are slimy, gel-like layers that surround many types of bacteria. They are made up of polysaccharides, proteins, or lipopolysaccharides and are synthesized by the bacterial cell. These capsules play a crucial role in the virulence and pathogenicity of bacteria as they help the bacteria to evade the host's immune system and promote their survival and colonization within the host. The presence of a capsule can also contribute to the bacteria's resistance to desiccation, phagocytosis, and antibiotics.

The chemical composition and structure of bacterial capsules vary among different species of bacteria, which is one factor that contributes to their serological specificity and allows for their identification and classification using methods such as the Quellung reaction or immunofluorescence microscopy.

Enzyme precursors are typically referred to as zymogens or proenzymes. These are inactive forms of enzymes that can be activated under specific conditions. When the need for the enzyme's function arises, the proenzyme is converted into its active form through a process called proteolysis, where it is cleaved by another enzyme. This mechanism helps control and regulate the activation of certain enzymes in the body, preventing unwanted or premature reactions. A well-known example of an enzyme precursor is trypsinogen, which is converted into its active form, trypsin, in the digestive system.

The Forssman antigen is a type of heterophile antigen, which is a substance that can stimulate an immune response in animals of different species. It was first discovered by the Swedish bacteriologist, John Forssman, in 1911. The Forssman antigen is found in a variety of tissues and organs, including the kidney, liver, and brain, in many different animal species, including humans.

The Forssman antigen is unique because it can induce the production of antibodies that cross-react with tissues from other species. This means that an immune response to the Forssman antigen in one species can also recognize and react with similar antigens in another species, leading to the possibility of cross-species immune reactions.

The Forssman antigen is a complex glycosphingolipid molecule that is found on the surface of cells. It is not clear what role, if any, the Forssman antigen plays in normal physiological processes. However, its presence has been implicated in various disease processes, including autoimmune disorders and transplant rejection.

In summary, the Forssman antigen is a heterophile antigen found in a variety of tissues and organs in many different animal species, including humans. It can induce cross-reacting antibodies and has been implicated in various disease processes.

"Swine" is a common term used to refer to even-toed ungulates of the family Suidae, including domestic pigs and wild boars. However, in a medical context, "swine" often appears in the phrase "swine flu," which is a strain of influenza virus that typically infects pigs but can also cause illness in humans. The 2009 H1N1 pandemic was caused by a new strain of swine-origin influenza A virus, which was commonly referred to as "swine flu." It's important to note that this virus is not transmitted through eating cooked pork products; it spreads from person to person, mainly through respiratory droplets produced when an infected person coughs or sneezes.

A lung is a pair of spongy, elastic organs in the chest that work together to enable breathing. They are responsible for taking in oxygen and expelling carbon dioxide through the process of respiration. The left lung has two lobes, while the right lung has three lobes. The lungs are protected by the ribcage and are covered by a double-layered membrane called the pleura. The trachea divides into two bronchi, which further divide into smaller bronchioles, leading to millions of tiny air sacs called alveoli, where the exchange of gases occurs.

"Borrelia" is a genus of spirochete bacteria that are known to cause several tick-borne diseases in humans, the most notable being Lyme disease. The bacteria are transmitted to humans through the bite of infected black-legged ticks (Ixodes scapularis in the United States and Ixodes pacificus on the West Coast).

The Borrelia species are gram-negative, helical-shaped bacteria with distinctive endoflagella that allow them to move in a corkscrew-like motion. They are microaerophilic, meaning they require a low oxygen environment for growth. The bacteria can survive in a variety of environments, including the digestive tracts of ticks and mammals, as well as in soil and water.

Lyme disease, caused by Borrelia burgdorferi, is the most common tick-borne illness in the United States. It typically presents with a characteristic rash called erythema migrans, fever, headache, and fatigue. If left untreated, the infection can spread to other parts of the body, causing arthritis, neurological problems, and cardiac issues.

Other Borrelia species, such as B. afzelii and B. garinii, are responsible for causing Lyme disease in Europe and Asia. Additionally, some Borrelia species have been linked to other tick-borne illnesses, including relapsing fever and tick-borne meningoencephalitis.

Prevention of Borrelia infections involves avoiding tick-infested areas, using insect repellent, checking for ticks after being outdoors, and promptly removing attached ticks. If a tick bite is suspected, it's important to seek medical attention and monitor for symptoms of infection. Early diagnosis and treatment with antibiotics can help prevent the development of chronic symptoms.

Bacterial DNA refers to the genetic material found in bacteria. It is composed of a double-stranded helix containing four nucleotide bases - adenine (A), thymine (T), guanine (G), and cytosine (C) - that are linked together by phosphodiester bonds. The sequence of these bases in the DNA molecule carries the genetic information necessary for the growth, development, and reproduction of bacteria.

Bacterial DNA is circular in most bacterial species, although some have linear chromosomes. In addition to the main chromosome, many bacteria also contain small circular pieces of DNA called plasmids that can carry additional genes and provide resistance to antibiotics or other environmental stressors.

Unlike eukaryotic cells, which have their DNA enclosed within a nucleus, bacterial DNA is present in the cytoplasm of the cell, where it is in direct contact with the cell's metabolic machinery. This allows for rapid gene expression and regulation in response to changing environmental conditions.

Beta-globulins are a group of proteins found in the beta region of a serum protein electrophoresis, which is a laboratory test used to separate and identify different types of proteins in the blood. This group includes several important proteins such as:

1. Beta-lipoproteins: These are responsible for transporting fat molecules, including cholesterol, throughout the body.
2. Transferrin: A protein that binds and transports iron in the blood.
3. Complement components: These proteins play a crucial role in the immune system's response to infection and inflammation.
4. Beta-2 microglobulin: A protein involved in the functioning of the immune system, elevated levels of which can be found in various conditions such as kidney disease and autoimmune disorders.
5. Hemopexin: A protein that binds and transports heme (a component of hemoglobin) in the blood.

It is important to note that any significant increase or decrease in beta-globulins can indicate an underlying medical condition, such as liver disease, kidney disease, or an autoimmune disorder. Therefore, abnormal results should be further evaluated by a healthcare professional for proper diagnosis and treatment.

Variola virus is the causative agent of smallpox, a highly contagious and deadly disease that was eradicated in 1980 due to a successful global vaccination campaign led by the World Health Organization (WHO). The virus belongs to the family Poxviridae and genus Orthopoxvirus. It is a large, enveloped, double-stranded DNA virus with a complex structure that includes a lipoprotein membrane and an outer protein layer called the lateral body.

The Variola virus has two main clinical forms: variola major and variola minor. Variola major is more severe and deadly, with a mortality rate of up to 30%, while variola minor is less severe and has a lower mortality rate. The virus is transmitted through direct contact with infected individuals or contaminated objects, such as clothing or bedding.

Smallpox was once a major public health threat worldwide, causing millions of deaths and severe illnesses. However, since its eradication, Variola virus has been kept in secure laboratories for research purposes only. The virus is considered a potential bioterrorism agent, and efforts are being made to develop new vaccines and antiviral treatments to protect against possible future outbreaks.

A leukocyte count, also known as a white blood cell (WBC) count, is a laboratory test that measures the number of leukocytes in a sample of blood. Leukocytes are a vital part of the body's immune system and help fight infection and inflammation. A high or low leukocyte count may indicate an underlying medical condition, such as an infection, inflammation, or a bone marrow disorder. The normal range for a leukocyte count in adults is typically between 4,500 and 11,000 cells per microliter (mcL) of blood. However, the normal range can vary slightly depending on the laboratory and the individual's age and sex.

Transfection is a term used in molecular biology that refers to the process of deliberately introducing foreign genetic material (DNA, RNA or artificial gene constructs) into cells. This is typically done using chemical or physical methods, such as lipofection or electroporation. Transfection is widely used in research and medical settings for various purposes, including studying gene function, producing proteins, developing gene therapies, and creating genetically modified organisms. It's important to note that transfection is different from transduction, which is the process of introducing genetic material into cells using viruses as vectors.

Iodine isotopes are different forms of the chemical element iodine, which have different numbers of neutrons in their nuclei. Iodine has a total of 53 protons in its nucleus, and its stable isotope, iodine-127, has 74 neutrons, giving it a mass number of 127. However, there are also radioactive isotopes of iodine, which have different numbers of neutrons and are therefore unstable.

Radioactive isotopes of iodine emit radiation as they decay towards a stable state. For example, iodine-131 is a commonly used isotope in medical imaging and therapy, with a half-life of about 8 days. It decays by emitting beta particles and gamma rays, making it useful for treating thyroid cancer and other conditions that involve overactive thyroid glands.

Other radioactive iodine isotopes include iodine-123, which has a half-life of about 13 hours and is used in medical imaging, and iodine-125, which has a half-life of about 60 days and is used in brachytherapy (a type of radiation therapy that involves placing radioactive sources directly into or near tumors).

It's important to note that exposure to radioactive iodine isotopes can be harmful, especially if it occurs through inhalation or ingestion. This is because the iodine can accumulate in the thyroid gland and cause damage over time. Therefore, appropriate safety measures must be taken when handling or working with radioactive iodine isotopes.

Amino acid repetitive sequences refer to patterns of amino acids that are repeated in a polypeptide chain. These repetitions can vary in length and can be composed of a single type of amino acid or a combination of different types. In some cases, expansions of these repetitive sequences can lead to the production of abnormal proteins that are associated with certain genetic disorders. The expansion of trinucleotide repeats that code for particular amino acids is one example of this phenomenon. These expansions can result in protein misfolding and aggregation, leading to neurodegenerative diseases such as Huntington's disease and spinocerebellar ataxias.

Two-dimensional immunoelectrophoresis (2DE) is a specialized laboratory technique used in the field of clinical pathology and immunology. This technique is a refined version of traditional immunoelectrophoresis that adds an additional electrophoretic separation step, enhancing its resolution and allowing for more detailed analysis of complex protein mixtures.

In two-dimensional immunoelectrophoresis, proteins are first separated based on their isoelectric points (pI) in the initial dimension using isoelectric focusing (IEF). This process involves applying an electric field to a protein mixture contained within a gel matrix, where proteins will migrate and stop migrating once they reach the pH that matches their own isoelectric point.

Following IEF, the separated proteins are then subjected to a second electrophoretic separation in the perpendicular direction (second dimension) based on their molecular weights using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). SDS is a negatively charged molecule that binds to proteins, giving them a uniform negative charge and allowing for separation based solely on size.

Once the two-dimensional separation is complete, the gel is then overlaid with specific antisera to detect and identify proteins of interest. The resulting precipitin arcs formed at the intersection of the antibody and antigen are compared to known standards or patterns to determine the identity and quantity of the separated proteins.

Two-dimensional immunoelectrophoresis is particularly useful in identifying and quantifying proteins in complex mixtures, such as those found in body fluids like serum, urine, or cerebrospinal fluid (CSF). It can be applied to various clinical scenarios, including diagnosis and monitoring of monoclonal gammopathies, autoimmune disorders, and certain infectious diseases.

Antilymphocyte serum (ALS) is a type of immune serum that contains antibodies against human lymphocytes. It is produced by immunizing animals, such as horses or rabbits, with human lymphocytes to stimulate an immune response and the production of anti-lymphocyte antibodies. The resulting serum is then collected and can be used as a therapeutic agent to suppress the activity of the immune system in certain medical conditions.

ALS is primarily used in the treatment of transplant rejection, particularly in organ transplantation, where it helps to prevent the recipient's immune system from attacking and rejecting the transplanted organ. It can also be used in the management of autoimmune diseases, such as rheumatoid arthritis and lupus, to suppress the overactive immune response that contributes to these conditions.

It is important to note that the use of ALS carries a risk of side effects, including allergic reactions, fever, and decreased white blood cell counts. Close monitoring and appropriate management of these potential adverse events are essential during treatment with ALS.

Molecular evolution is the process of change in the DNA sequence or protein structure over time, driven by mechanisms such as mutation, genetic drift, gene flow, and natural selection. It refers to the evolutionary study of changes in DNA, RNA, and proteins, and how these changes accumulate and lead to new species and diversity of life. Molecular evolution can be used to understand the history and relationships among different organisms, as well as the functional consequences of genetic changes.

Immunologic techniques are a group of laboratory methods that utilize the immune system's ability to recognize and respond to specific molecules, known as antigens. These techniques are widely used in medicine, biology, and research to detect, measure, or identify various substances, including proteins, hormones, viruses, bacteria, and other antigens.

Some common immunologic techniques include:

1. Enzyme-linked Immunosorbent Assay (ELISA): A sensitive assay used to detect and quantify antigens or antibodies in a sample. This technique uses an enzyme linked to an antibody or antigen, which reacts with a substrate to produce a colored product that can be measured and quantified.
2. Immunofluorescence: A microscopic technique used to visualize the location of antigens or antibodies in tissues or cells. This technique uses fluorescent dyes conjugated to antibodies, which bind to specific antigens and emit light when excited by a specific wavelength of light.
3. Western Blotting: A laboratory technique used to detect and identify specific proteins in a sample. This technique involves separating proteins based on their size using electrophoresis, transferring them to a membrane, and then probing the membrane with antibodies that recognize the protein of interest.
4. Immunoprecipitation: A laboratory technique used to isolate and purify specific antigens or antibodies from a complex mixture. This technique involves incubating the mixture with an antibody that recognizes the antigen or antibody of interest, followed by precipitation of the antigen-antibody complex using a variety of methods.
5. Radioimmunoassay (RIA): A sensitive assay used to detect and quantify antigens or antibodies in a sample. This technique uses radioactively labeled antigens or antibodies, which bind to specific antigens or antibodies in the sample, allowing for detection and quantification using a scintillation counter.

These techniques are important tools in medical diagnosis, research, and forensic science.

Blood platelets, also known as thrombocytes, are small, colorless cell fragments in our blood that play an essential role in normal blood clotting. They are formed in the bone marrow from large cells called megakaryocytes and circulate in the blood in an inactive state until they are needed to help stop bleeding. When a blood vessel is damaged, platelets become activated and change shape, releasing chemicals that attract more platelets to the site of injury. These activated platelets then stick together to form a plug, or clot, that seals the wound and prevents further blood loss. In addition to their role in clotting, platelets also help to promote healing by releasing growth factors that stimulate the growth of new tissue.

Immune system diseases, also known as immunological disorders or autoimmune diseases, refer to a group of conditions in which the immune system mistakenly attacks and damages healthy tissues in the body. The immune system is designed to protect the body from harmful substances such as viruses, bacteria, and toxins. However, in immune system diseases, the immune system fails to distinguish between these harmful substances and the body's own cells, leading to an overactive or misdirected response.

There are several types of immune system diseases, including:

1. Allergies: An abnormal immune response to harmless substances such as pollen, dust mites, or certain foods.
2. Autoimmune disorders: A group of conditions in which the immune system attacks healthy tissues, such as rheumatoid arthritis, lupus, and multiple sclerosis.
3. Immunodeficiency disorders: Conditions that weaken the immune system, making it harder for the body to fight off infections, such as HIV/AIDS or primary immunodeficiency diseases.
4. Autoinflammatory disorders: A group of conditions characterized by recurrent episodes of inflammation due to abnormal activation of the immune system, such as familial Mediterranean fever and cryopyrin-associated periodic syndromes.
5. Transplant rejection: A response in which the immune system attacks and rejects transplanted organs or tissues.

Immune system diseases can cause a wide range of symptoms, depending on the specific condition and the severity of the disease. Treatment may involve medications to suppress the immune system, as well as other therapies to manage symptoms and prevent complications.

Proteinuria is a medical term that refers to the presence of excess proteins, particularly albumin, in the urine. Under normal circumstances, only small amounts of proteins should be found in the urine because the majority of proteins are too large to pass through the glomeruli, which are the filtering units of the kidneys.

However, when the glomeruli become damaged or diseased, they may allow larger molecules such as proteins to leak into the urine. Persistent proteinuria is often a sign of kidney disease and can indicate damage to the glomeruli. It is usually detected through a routine urinalysis and may be confirmed with further testing.

The severity of proteinuria can vary, and it can be a symptom of various underlying conditions such as diabetes, hypertension, glomerulonephritis, and other kidney diseases. Treatment for proteinuria depends on the underlying cause and may include medications to control blood pressure, manage diabetes, or reduce protein loss in the urine.

Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.

Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.

Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.

Fibrinogen is a soluble protein present in plasma, synthesized by the liver. It plays an essential role in blood coagulation. When an injury occurs, fibrinogen gets converted into insoluble fibrin by the action of thrombin, forming a fibrin clot that helps to stop bleeding from the injured site. Therefore, fibrinogen is crucial for hemostasis, which is the process of stopping bleeding and starting the healing process after an injury.

In medical terms, the skin is the largest organ of the human body. It consists of two main layers: the epidermis (outer layer) and dermis (inner layer), as well as accessory structures like hair follicles, sweat glands, and oil glands. The skin plays a crucial role in protecting us from external factors such as bacteria, viruses, and environmental hazards, while also regulating body temperature and enabling the sense of touch.

Gene expression profiling is a laboratory technique used to measure the activity (expression) of thousands of genes at once. This technique allows researchers and clinicians to identify which genes are turned on or off in a particular cell, tissue, or organism under specific conditions, such as during health, disease, development, or in response to various treatments.

The process typically involves isolating RNA from the cells or tissues of interest, converting it into complementary DNA (cDNA), and then using microarray or high-throughput sequencing technologies to determine which genes are expressed and at what levels. The resulting data can be used to identify patterns of gene expression that are associated with specific biological states or processes, providing valuable insights into the underlying molecular mechanisms of diseases and potential targets for therapeutic intervention.

In recent years, gene expression profiling has become an essential tool in various fields, including cancer research, drug discovery, and personalized medicine, where it is used to identify biomarkers of disease, predict patient outcomes, and guide treatment decisions.

Southern blotting is a type of membrane-based blotting technique that is used in molecular biology to detect and locate specific DNA sequences within a DNA sample. This technique is named after its inventor, Edward M. Southern.

In Southern blotting, the DNA sample is first digested with one or more restriction enzymes, which cut the DNA at specific recognition sites. The resulting DNA fragments are then separated based on their size by gel electrophoresis. After separation, the DNA fragments are denatured to convert them into single-stranded DNA and transferred onto a nitrocellulose or nylon membrane.

Once the DNA has been transferred to the membrane, it is hybridized with a labeled probe that is complementary to the sequence of interest. The probe can be labeled with radioactive isotopes, fluorescent dyes, or chemiluminescent compounds. After hybridization, the membrane is washed to remove any unbound probe and then exposed to X-ray film (in the case of radioactive probes) or scanned (in the case of non-radioactive probes) to detect the location of the labeled probe on the membrane.

The position of the labeled probe on the membrane corresponds to the location of the specific DNA sequence within the original DNA sample. Southern blotting is a powerful tool for identifying and characterizing specific DNA sequences, such as those associated with genetic diseases or gene regulation.

Fungal genes refer to the genetic material present in fungi, which are eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. The genetic material of fungi is composed of DNA, just like in other eukaryotes, and is organized into chromosomes located in the nucleus of the cell.

Fungal genes are segments of DNA that contain the information necessary to produce proteins and RNA molecules required for various cellular functions. These genes are transcribed into messenger RNA (mRNA) molecules, which are then translated into proteins by ribosomes in the cytoplasm.

Fungal genomes have been sequenced for many species, revealing a diverse range of genes that encode proteins involved in various cellular processes such as metabolism, signaling, and regulation. Comparative genomic analyses have also provided insights into the evolutionary relationships among different fungal lineages and have helped to identify unique genetic features that distinguish fungi from other eukaryotes.

Understanding fungal genes and their functions is essential for advancing our knowledge of fungal biology, as well as for developing new strategies to control fungal pathogens that can cause diseases in humans, animals, and plants.

Heterophile antigens are a type of antigen that can induce an immune response in multiple species, not just the one they originate from. They are called "heterophile" because they exhibit cross-reactivity with antibodies produced against different antigens from other species. A common example of heterophile antigens is the Forssman antigen, which can be found in various animals such as guinea pigs, rabbits, and humans.

Heterophile antibody tests are often used in diagnostic medicine to detect certain infections or autoimmune disorders. One well-known example is the Paul-Bunnell test, which was historically used to diagnose infectious mononucleosis (IM) caused by the Epstein-Barr virus (EBV). The test detects heterophile antibodies produced against EBV antigens that cross-react with sheep red blood cells. However, this test has been largely replaced by more specific and sensitive EBV antibody tests.

It is important to note that heterophile antibody tests can sometimes produce false positive results due to the presence of these cross-reactive antibodies in individuals who have not been infected with the targeted pathogen. Therefore, it is crucial to interpret test results cautiously and consider them alongside clinical symptoms, medical history, and other diagnostic findings.

I'm happy to help! "Rats, Inbred Lew" is a specific strain of laboratory rats that have been inbred for research purposes. The "Lew" part of the name refers to the location where they were first developed, the Lewis Institute in Lake Bluff, Illinois, USA.

Inbreeding is a process of mating closely related individuals over many generations to create a genetically homogeneous population. This results in a high degree of genetic similarity among members of the strain, making them ideal for use as experimental models because any differences observed between individuals are more likely to be due to the experimental manipulation rather than genetic variation.

Inbred Lew rats have been widely used in biomedical research, particularly in studies related to hypertension and cardiovascular disease. They exhibit a number of unique characteristics that make them useful for these types of studies, including their susceptibility to developing high blood pressure when fed a high-salt diet or given certain drugs.

It's important to note that while inbred strains like Lew rats can be very useful tools for researchers, they are not perfect models for human disease. Because they have been bred in a controlled environment and selected for specific traits, they may not respond to experimental manipulations in the same way that humans or other animals would. Therefore, it's important to interpret findings from these studies with caution and consider multiple lines of evidence before drawing any firm conclusions.

Antinuclear antibodies (ANA) are a type of autoantibody that target structures found in the nucleus of a cell. These antibodies are produced by the immune system and attack the body's own cells and tissues, leading to inflammation and damage. The presence of ANA is often used as a marker for certain autoimmune diseases, such as systemic lupus erythematosus (SLE), Sjogren's syndrome, rheumatoid arthritis, scleroderma, and polymyositis.

ANA can be detected through a blood test called the antinuclear antibody test. A positive result indicates the presence of ANA in the blood, but it does not necessarily mean that a person has an autoimmune disease. Further testing is usually needed to confirm a diagnosis and determine the specific type of autoantibodies present.

It's important to note that ANA can also be found in healthy individuals, particularly as they age. Therefore, the test results should be interpreted in conjunction with other clinical findings and symptoms.

Cell surface receptors, also known as membrane receptors, are proteins located on the cell membrane that bind to specific molecules outside the cell, known as ligands. These receptors play a crucial role in signal transduction, which is the process of converting an extracellular signal into an intracellular response.

Cell surface receptors can be classified into several categories based on their structure and mechanism of action, including:

1. Ion channel receptors: These receptors contain a pore that opens to allow ions to flow across the cell membrane when they bind to their ligands. This ion flux can directly activate or inhibit various cellular processes.
2. G protein-coupled receptors (GPCRs): These receptors consist of seven transmembrane domains and are associated with heterotrimeric G proteins that modulate intracellular signaling pathways upon ligand binding.
3. Enzyme-linked receptors: These receptors possess an intrinsic enzymatic activity or are linked to an enzyme, which becomes activated when the receptor binds to its ligand. This activation can lead to the initiation of various signaling cascades within the cell.
4. Receptor tyrosine kinases (RTKs): These receptors contain intracellular tyrosine kinase domains that become activated upon ligand binding, leading to the phosphorylation and activation of downstream signaling molecules.
5. Integrins: These receptors are transmembrane proteins that mediate cell-cell or cell-matrix interactions by binding to extracellular matrix proteins or counter-receptors on adjacent cells. They play essential roles in cell adhesion, migration, and survival.

Cell surface receptors are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and cell growth and differentiation. Dysregulation of these receptors can contribute to the development of numerous diseases, such as cancer, diabetes, and neurological disorders.

Complement C5 Convertase, Alternative Pathway is a protein complex that plays a crucial role in the alternative pathway of the complement system, which is a part of the immune system that helps to eliminate pathogens and damaged cells. The complement system consists of a group of proteins that work together to help recognize and destroy foreign substances, such as bacteria and viruses.

The alternative pathway is one of three pathways that can activate the complement system, and it is constantly active at low levels in the body. The C5 convertase enzyme is formed by the cleavage of a protein called C3 into two fragments, C3a and C3b. The C3b fragment then binds to another protein called factor B, which is activated by a protease called factor D to form the C3bBb complex, known as the C5 convertase of the alternative pathway.

The C5 convertase cleaves the complement protein C5 into two fragments, C5a and C5b. The C5a fragment acts as a chemoattractant, recruiting immune cells to the site of infection or injury. The C5b fragment, along with other complement proteins, forms the membrane attack complex (MAC), which creates a pore in the membrane of the target cell, leading to its lysis and death.

Regulation of the alternative pathway is critical to prevent damage to host cells and tissues. Several regulatory proteins, such as factor H and factor I, help to control the activation of the C5 convertase and limit its activity to prevent excessive complement activation. Dysregulation of the complement system has been implicated in various diseases, including autoimmune disorders, inflammatory conditions, and neurodegenerative diseases.

Saccharomyces cerevisiae proteins are the proteins that are produced by the budding yeast, Saccharomyces cerevisiae. This organism is a single-celled eukaryote that has been widely used as a model organism in scientific research for many years due to its relatively simple genetic makeup and its similarity to higher eukaryotic cells.

The genome of Saccharomyces cerevisiae has been fully sequenced, and it is estimated to contain approximately 6,000 genes that encode proteins. These proteins play a wide variety of roles in the cell, including catalyzing metabolic reactions, regulating gene expression, maintaining the structure of the cell, and responding to environmental stimuli.

Many Saccharomyces cerevisiae proteins have human homologs and are involved in similar biological processes, making this organism a valuable tool for studying human disease. For example, many of the proteins involved in DNA replication, repair, and recombination in yeast have human counterparts that are associated with cancer and other diseases. By studying these proteins in yeast, researchers can gain insights into their function and regulation in humans, which may lead to new treatments for disease.

Blood coagulation, also known as blood clotting, is a complex process that occurs in the body to prevent excessive bleeding when a blood vessel is damaged. This process involves several different proteins and chemical reactions that ultimately lead to the formation of a clot.

The coagulation cascade is initiated when blood comes into contact with tissue factor, which is exposed after damage to the blood vessel wall. This triggers a series of enzymatic reactions that activate clotting factors, leading to the formation of a fibrin clot. Fibrin is a protein that forms a mesh-like structure that traps platelets and red blood cells to form a stable clot.

Once the bleeding has stopped, the coagulation process is regulated and inhibited to prevent excessive clotting. The fibrinolytic system degrades the clot over time, allowing for the restoration of normal blood flow.

Abnormalities in the blood coagulation process can lead to bleeding disorders or thrombotic disorders such as deep vein thrombosis and pulmonary embolism.

Steroid 21-hydroxylase, also known as CYP21A2, is a crucial enzyme involved in the synthesis of steroid hormones in the adrenal gland. Specifically, it catalyzes the conversion of 17-hydroxyprogesterone to 11-deoxycortisol and progesterone to deoxycorticosterone in the glucocorticoid and mineralocorticoid pathways, respectively.

Deficiency or mutations in this enzyme can lead to a group of genetic disorders called congenital adrenal hyperplasia (CAH), which is characterized by impaired cortisol production and disrupted hormonal balance. Depending on the severity of the deficiency, CAH can result in various symptoms such as ambiguous genitalia, precocious puberty, sexual infantilism, infertility, and increased risk of adrenal crisis.

Immunoglobulins, also known as antibodies, are proteins produced by the immune system to recognize and neutralize foreign substances like pathogens or antigens. The term "immunoglobulin isotypes" refers to the different classes of immunoglobulins that share a similar structure but have distinct functions and properties.

There are five main isotypes of immunoglobulins in humans, namely IgA, IgD, IgE, IgG, and IgM. Each isotype has a unique heavy chain constant region (CH) that determines its effector functions, such as binding to Fc receptors, complement activation, or protection against pathogens.

IgA is primarily found in external secretions like tears, saliva, and breast milk, providing localized immunity at mucosal surfaces. IgD is expressed on the surface of B cells and plays a role in their activation and differentiation. IgE is associated with allergic responses and binds to mast cells and basophils, triggering the release of histamine and other mediators of inflammation.

IgG is the most abundant isotype in serum and has several subclasses (IgG1, IgG2, IgG3, and IgG4) that differ in their effector functions. IgG can cross the placenta, providing passive immunity to the fetus. IgM is the first antibody produced during an immune response and is primarily found in the bloodstream, where it forms large pentameric complexes that are effective at agglutination and complement activation.

Overall, immunoglobulin isotypes play a crucial role in the adaptive immune response, providing specific and diverse mechanisms for recognizing and neutralizing foreign substances.

'Escherichia coli (E. coli) proteins' refer to the various types of proteins that are produced and expressed by the bacterium Escherichia coli. These proteins play a critical role in the growth, development, and survival of the organism. They are involved in various cellular processes such as metabolism, DNA replication, transcription, translation, repair, and regulation.

E. coli is a gram-negative, facultative anaerobe that is commonly found in the intestines of warm-blooded organisms. It is widely used as a model organism in scientific research due to its well-studied genetics, rapid growth, and ability to be easily manipulated in the laboratory. As a result, many E. coli proteins have been identified, characterized, and studied in great detail.

Some examples of E. coli proteins include enzymes involved in carbohydrate metabolism such as lactase, sucrase, and maltose; proteins involved in DNA replication such as the polymerases, single-stranded binding proteins, and helicases; proteins involved in transcription such as RNA polymerase and sigma factors; proteins involved in translation such as ribosomal proteins, tRNAs, and aminoacyl-tRNA synthetases; and regulatory proteins such as global regulators, two-component systems, and transcription factors.

Understanding the structure, function, and regulation of E. coli proteins is essential for understanding the basic biology of this important organism, as well as for developing new strategies for combating bacterial infections and improving industrial processes involving bacteria.

Luminescent measurements refer to the quantitative assessment of the emission of light from a substance that has been excited, typically through some form of energy input such as electrical energy or radiation. In the context of medical diagnostics and research, luminescent measurements can be used in various applications, including bioluminescence imaging, which is used to study biological processes at the cellular and molecular level.

Bioluminescence occurs when a chemical reaction produces light within a living organism, often through the action of enzymes such as luciferase. By introducing a luciferase gene into cells or organisms, researchers can use bioluminescent measurements to track cellular processes and monitor gene expression in real time.

Luminescent measurements may also be used in medical research to study the properties of materials used in medical devices, such as LEDs or optical fibers, or to develop new diagnostic tools based on light-emitting nanoparticles or other luminescent materials.

In summary, luminescent measurements are a valuable tool in medical research and diagnostics, providing a non-invasive way to study biological processes and develop new technologies for disease detection and treatment.

Autoimmune diseases are a group of disorders in which the immune system, which normally protects the body from foreign invaders like bacteria and viruses, mistakenly attacks the body's own cells and tissues. This results in inflammation and damage to various organs and tissues in the body.

In autoimmune diseases, the body produces autoantibodies that target its own proteins or cell receptors, leading to their destruction or malfunction. The exact cause of autoimmune diseases is not fully understood, but it is believed that a combination of genetic and environmental factors contribute to their development.

There are over 80 different types of autoimmune diseases, including rheumatoid arthritis, lupus, multiple sclerosis, type 1 diabetes, Hashimoto's thyroiditis, Graves' disease, psoriasis, and inflammatory bowel disease. Symptoms can vary widely depending on the specific autoimmune disease and the organs or tissues affected. Treatment typically involves managing symptoms and suppressing the immune system to prevent further damage.

Membranous glomerulonephritis (MGN) is a kidney disorder that leads to the inflammation and damage of the glomeruli, which are the tiny blood vessels in the kidneys responsible for filtering waste and excess fluids from the blood. In MGN, the membrane that surrounds the glomerular capillaries becomes thickened and damaged due to the deposit of immune complexes, primarily composed of antibodies and antigens.

The onset of membranous glomerulonephritis can be either primary (idiopathic) or secondary to various underlying conditions such as autoimmune diseases (like systemic lupus erythematosus), infections (hepatitis B or C, syphilis, endocarditis), medications, or malignancies.

The symptoms of membranous glomerulonephritis may include:

1. Proteinuria - the presence of excess protein, specifically albumin, in the urine. This can lead to nephrotic syndrome, characterized by heavy protein loss in urine, edema (swelling), hypoalbuminemia (low blood albumin levels), and hyperlipidemia (high blood lipid levels).
2. Hematuria - the presence of red blood cells in the urine, which can be visible or microscopic.
3. Hypertension - high blood pressure.
4. Edema - swelling in various body parts due to fluid retention.
5. Nephrotic range proteinuria (protein loss greater than 3.5 grams per day) and/or nephritic syndrome (a combination of hematuria, proteinuria, hypertension, and kidney dysfunction) can be observed in some cases.

The diagnosis of membranous glomerulonephritis typically involves a thorough medical history, physical examination, urinalysis, blood tests, and imaging studies. A definitive diagnosis often requires a kidney biopsy to assess the glomerular structure and the nature of the immune complex deposits. Treatment depends on the underlying cause and severity of the disease and may include corticosteroids, immunosuppressants, blood pressure management, and supportive care for symptoms like edema and proteinuria.

Ascitic fluid is defined as the abnormal accumulation of fluid in the peritoneal cavity, which is the space between the two layers of the peritoneum, a serous membrane that lines the abdominal cavity and covers the abdominal organs. This buildup of fluid, also known as ascites, can be caused by various medical conditions such as liver cirrhosis, cancer, heart failure, or infection. The fluid itself is typically straw-colored and clear, but it may also contain cells, proteins, and other substances depending on the underlying cause. Analysis of ascitic fluid can help doctors diagnose and manage the underlying condition causing the accumulation of fluid.

Lymphocyte activation is the process by which B-cells and T-cells (types of lymphocytes) become activated to perform effector functions in an immune response. This process involves the recognition of specific antigens presented on the surface of antigen-presenting cells, such as dendritic cells or macrophages.

The activation of B-cells leads to their differentiation into plasma cells that produce antibodies, while the activation of T-cells results in the production of cytotoxic T-cells (CD8+ T-cells) that can directly kill infected cells or helper T-cells (CD4+ T-cells) that assist other immune cells.

Lymphocyte activation involves a series of intracellular signaling events, including the binding of co-stimulatory molecules and the release of cytokines, which ultimately result in the expression of genes involved in cell proliferation, differentiation, and effector functions. The activation process is tightly regulated to prevent excessive or inappropriate immune responses that can lead to autoimmunity or chronic inflammation.

Mannose-binding lectins (MBLs) are a group of proteins that belong to the collectin family and play a crucial role in the innate immune system. They are primarily produced by the liver and secreted into the bloodstream. MBLs have a specific affinity for mannose sugar residues found on the surface of various microorganisms, including bacteria, viruses, fungi, and parasites.

The primary function of MBLs is to recognize and bind to these mannose-rich structures, which triggers the complement system's activation through the lectin pathway. This process leads to the destruction of the microorganism by opsonization (coating the microbe to enhance phagocytosis) or direct lysis. MBLs also have the ability to neutralize certain viruses and inhibit the replication of others, further contributing to their antimicrobial activity.

Deficiencies in MBL levels or function have been associated with an increased susceptibility to infections, particularly in children and older adults. However, the clinical significance of MBL deficiency remains a subject of ongoing research.

A ligand, in the context of biochemistry and medicine, is a molecule that binds to a specific site on a protein or a larger biomolecule, such as an enzyme or a receptor. This binding interaction can modify the function or activity of the target protein, either activating it or inhibiting it. Ligands can be small molecules, like hormones or neurotransmitters, or larger structures, like antibodies. The study of ligand-protein interactions is crucial for understanding cellular processes and developing drugs, as many therapeutic compounds function by binding to specific targets within the body.

A sequence deletion in a genetic context refers to the removal or absence of one or more nucleotides (the building blocks of DNA or RNA) from a specific region in a DNA or RNA molecule. This type of mutation can lead to the loss of genetic information, potentially resulting in changes in the function or expression of a gene. If the deletion involves a critical portion of the gene, it can cause diseases, depending on the role of that gene in the body. The size of the deleted sequence can vary, ranging from a single nucleotide to a large segment of DNA.

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Transgenic mice are genetically modified rodents that have incorporated foreign DNA (exogenous DNA) into their own genome. This is typically done through the use of recombinant DNA technology, where a specific gene or genetic sequence of interest is isolated and then introduced into the mouse embryo. The resulting transgenic mice can then express the protein encoded by the foreign gene, allowing researchers to study its function in a living organism.

The process of creating transgenic mice usually involves microinjecting the exogenous DNA into the pronucleus of a fertilized egg, which is then implanted into a surrogate mother. The offspring that result from this procedure are screened for the presence of the foreign DNA, and those that carry the desired genetic modification are used to establish a transgenic mouse line.

Transgenic mice have been widely used in biomedical research to model human diseases, study gene function, and test new therapies. They provide a valuable tool for understanding complex biological processes and developing new treatments for a variety of medical conditions.

Genetic polymorphism refers to the occurrence of multiple forms (called alleles) of a particular gene within a population. These variations in the DNA sequence do not generally affect the function or survival of the organism, but they can contribute to differences in traits among individuals. Genetic polymorphisms can be caused by single nucleotide changes (SNPs), insertions or deletions of DNA segments, or other types of genetic rearrangements. They are important for understanding genetic diversity and evolution, as well as for identifying genetic factors that may contribute to disease susceptibility in humans.

Muramidase, also known as lysozyme, is an enzyme that hydrolyzes the glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine in peptidoglycan, a polymer found in bacterial cell walls. This enzymatic activity plays a crucial role in the innate immune system by contributing to the destruction of invading bacteria. Muramidase is widely distributed in various tissues and bodily fluids, such as tears, saliva, and milk, and is also found in several types of white blood cells, including neutrophils and monocytes.

An open reading frame (ORF) is a continuous stretch of DNA or RNA sequence that has the potential to be translated into a protein. It begins with a start codon (usually "ATG" in DNA, which corresponds to "AUG" in RNA) and ends with a stop codon ("TAA", "TAG", or "TGA" in DNA; "UAA", "UAG", or "UGA" in RNA). The sequence between these two points is called a coding sequence (CDS), which, when transcribed into mRNA and translated into amino acids, forms a polypeptide chain.

In eukaryotic cells, ORFs can be located in either protein-coding genes or non-coding regions of the genome. In prokaryotic cells, multiple ORFs may be present on a single strand of DNA, often organized into operons that are transcribed together as a single mRNA molecule.

It's important to note that not all ORFs necessarily represent functional proteins; some may be pseudogenes or result from errors in genome annotation. Therefore, additional experimental evidence is typically required to confirm the expression and functionality of a given ORF.

A case-control study is an observational research design used to identify risk factors or causes of a disease or health outcome. In this type of study, individuals with the disease or condition (cases) are compared with similar individuals who do not have the disease or condition (controls). The exposure history or other characteristics of interest are then compared between the two groups to determine if there is an association between the exposure and the disease.

Case-control studies are often used when it is not feasible or ethical to conduct a randomized controlled trial, as they can provide valuable insights into potential causes of diseases or health outcomes in a relatively short period of time and at a lower cost than other study designs. However, because case-control studies rely on retrospective data collection, they are subject to biases such as recall bias and selection bias, which can affect the validity of the results. Therefore, it is important to carefully design and conduct case-control studies to minimize these potential sources of bias.

An antigen is any substance that can stimulate an immune response, particularly the production of antibodies. Viral antigens are antigens that are found on or produced by viruses. They can be proteins, glycoproteins, or carbohydrates present on the surface or inside the viral particle.

Viral antigens play a crucial role in the immune system's recognition and response to viral infections. When a virus infects a host cell, it may display its antigens on the surface of the infected cell. This allows the immune system to recognize and target the infected cells for destruction, thereby limiting the spread of the virus.

Viral antigens are also important targets for vaccines. Vaccines typically work by introducing a harmless form of a viral antigen to the body, which then stimulates the production of antibodies and memory T-cells that can recognize and respond quickly and effectively to future infections with the actual virus.

It's worth noting that different types of viruses have different antigens, and these antigens can vary between strains of the same virus. This is why there are often different vaccines available for different viral diseases, and why flu vaccines need to be updated every year to account for changes in the circulating influenza virus strains.

Immunization is defined medically as the process where an individual is made immune or resistant to an infectious disease, typically through the administration of a vaccine. The vaccine stimulates the body's own immune system to recognize and fight off the specific disease-causing organism, thereby preventing or reducing the severity of future infections with that organism.

Immunization can be achieved actively, where the person is given a vaccine to trigger an immune response, or passively, where antibodies are transferred to the person through immunoglobulin therapy. Immunizations are an important part of preventive healthcare and have been successful in controlling and eliminating many infectious diseases worldwide.

Agammaglobulinemia is a medical condition characterized by a severe deficiency or complete absence of gamma globulins (a type of antibodies) in the blood. This deficiency results from a lack of functional B cells, which are a type of white blood cell that produces antibodies to help fight off infections.

There are two main types of agammaglobulinemia: X-linked agammaglobulinemia (XLA) and autosomal recessive agammaglobulinemia (ARA). XLA is caused by mutations in the BTK gene and primarily affects males, while ARA is caused by mutations in other genes and can affect both males and females.

People with agammaglobulinemia are at increased risk for recurrent bacterial infections, particularly respiratory tract infections such as pneumonia and sinusitis. They may also be more susceptible to certain viral and parasitic infections. Treatment typically involves replacement therapy with intravenous immunoglobulin (IVIG) to provide the patient with functional antibodies.

Trypanosomiasis is a parasitic disease caused by various species of the protozoan genus Trypanosoma. It is transmitted through the bite of an infected tsetse fly (in African trypanosomiasis or sleeping sickness) or reduviid bug (in American trypanosomiasis or Chagas disease). The parasites enter the bloodstream and lymphatic system, causing symptoms such as fever, swollen lymph nodes, skin lesions, and muscle pain. Untreated, it can lead to severe neurological complications and death in both forms of the disease. Prevention measures include avoiding insect bites, using insect repellents, and sleeping under insecticide-treated bed nets.

Precipitins are antibodies (usually of the IgG class) that, when combined with their respective antigens in vitro, result in the formation of a visible precipitate. They are typically produced in response to the presence of insoluble antigens, such as bacterial or fungal cell wall components, and can be detected through various immunological techniques such as precipitation tests (e.g., Ouchterlony double diffusion, radial immunodiffusion).

Precipitins are often used in the diagnosis of infectious diseases, autoimmune disorders, and allergies to identify the presence and specificity of antibodies produced against certain antigens. However, it's worth noting that the term "precipitin" is not commonly used in modern medical literature, and the more general term "antibody" is often preferred.

Affinity chromatography is a type of chromatography technique used in biochemistry and molecular biology to separate and purify proteins based on their biological characteristics, such as their ability to bind specifically to certain ligands or molecules. This method utilizes a stationary phase that is coated with a specific ligand (e.g., an antibody, antigen, receptor, or enzyme) that selectively interacts with the target protein in a sample.

The process typically involves the following steps:

1. Preparation of the affinity chromatography column: The stationary phase, usually a solid matrix such as agarose beads or magnetic beads, is modified by covalently attaching the ligand to its surface.
2. Application of the sample: The protein mixture is applied to the top of the affinity chromatography column, allowing it to flow through the stationary phase under gravity or pressure.
3. Binding and washing: As the sample flows through the column, the target protein selectively binds to the ligand on the stationary phase, while other proteins and impurities pass through. The column is then washed with a suitable buffer to remove any unbound proteins and contaminants.
4. Elution of the bound protein: The target protein can be eluted from the column using various methods, such as changing the pH, ionic strength, or polarity of the buffer, or by introducing a competitive ligand that displaces the bound protein.
5. Collection and analysis: The eluted protein fraction is collected and analyzed for purity and identity, often through techniques like SDS-PAGE or mass spectrometry.

Affinity chromatography is a powerful tool in biochemistry and molecular biology due to its high selectivity and specificity, enabling the efficient isolation of target proteins from complex mixtures. However, it requires careful consideration of the binding affinity between the ligand and the protein, as well as optimization of the elution conditions to minimize potential damage or denaturation of the purified protein.

Cell adhesion refers to the binding of cells to extracellular matrices or to other cells, a process that is fundamental to the development, function, and maintenance of multicellular organisms. Cell adhesion is mediated by various cell surface receptors, such as integrins, cadherins, and immunoglobulin-like cell adhesion molecules (Ig-CAMs), which interact with specific ligands in the extracellular environment. These interactions lead to the formation of specialized junctions, such as tight junctions, adherens junctions, and desmosomes, that help to maintain tissue architecture and regulate various cellular processes, including proliferation, differentiation, migration, and survival. Disruptions in cell adhesion can contribute to a variety of diseases, including cancer, inflammation, and degenerative disorders.

I apologize, but I am not able to provide a medical definition for "Egtazic Acid" because it is not a term that is recognized in the field of medicine or pharmacology. It is possible that you may have meant "Egтарic Acid," which also does not have a specific medical meaning, or "Ethylene Glycol Tetraacetic Acid (EGTA)," which is a chemical compound used in research and medicine for its ability to bind calcium ions. If you have any other questions, I would be happy to try to help answer them.

Genetic predisposition to disease refers to an increased susceptibility or vulnerability to develop a particular illness or condition due to inheriting specific genetic variations or mutations from one's parents. These genetic factors can make it more likely for an individual to develop a certain disease, but it does not guarantee that the person will definitely get the disease. Environmental factors, lifestyle choices, and interactions between genes also play crucial roles in determining if a genetically predisposed person will actually develop the disease. It is essential to understand that having a genetic predisposition only implies a higher risk, not an inevitable outcome.

Fluorescence microscopy is a type of microscopy that uses fluorescent dyes or proteins to highlight and visualize specific components within a sample. In this technique, the sample is illuminated with high-energy light, typically ultraviolet (UV) or blue light, which excites the fluorescent molecules causing them to emit lower-energy, longer-wavelength light, usually visible light in the form of various colors. This emitted light is then collected by the microscope and detected to produce an image.

Fluorescence microscopy has several advantages over traditional brightfield microscopy, including the ability to visualize specific structures or molecules within a complex sample, increased sensitivity, and the potential for quantitative analysis. It is widely used in various fields of biology and medicine, such as cell biology, neuroscience, and pathology, to study the structure, function, and interactions of cells and proteins.

There are several types of fluorescence microscopy techniques, including widefield fluorescence microscopy, confocal microscopy, two-photon microscopy, and total internal reflection fluorescence (TIRF) microscopy, each with its own strengths and limitations. These techniques can provide valuable insights into the behavior of cells and proteins in health and disease.

Gene expression regulation in bacteria refers to the complex cellular processes that control the production of proteins from specific genes. This regulation allows bacteria to adapt to changing environmental conditions and ensure the appropriate amount of protein is produced at the right time.

Bacteria have a variety of mechanisms for regulating gene expression, including:

1. Operon structure: Many bacterial genes are organized into operons, which are clusters of genes that are transcribed together as a single mRNA molecule. The expression of these genes can be coordinately regulated by controlling the transcription of the entire operon.
2. Promoter regulation: Transcription is initiated at promoter regions upstream of the gene or operon. Bacteria have regulatory proteins called sigma factors that bind to the promoter and recruit RNA polymerase, the enzyme responsible for transcribing DNA into RNA. The binding of sigma factors can be influenced by environmental signals, allowing for regulation of transcription.
3. Attenuation: Some operons have regulatory regions called attenuators that control transcription termination. These regions contain hairpin structures that can form in the mRNA and cause transcription to stop prematurely. The formation of these hairpins is influenced by the concentration of specific metabolites, allowing for regulation of gene expression based on the availability of those metabolites.
4. Riboswitches: Some bacterial mRNAs contain regulatory elements called riboswitches that bind small molecules directly. When a small molecule binds to the riboswitch, it changes conformation and affects transcription or translation of the associated gene.
5. CRISPR-Cas systems: Bacteria use CRISPR-Cas systems for adaptive immunity against viruses and plasmids. These systems incorporate short sequences from foreign DNA into their own genome, which can then be used to recognize and cleave similar sequences in invading genetic elements.

Overall, gene expression regulation in bacteria is a complex process that allows them to respond quickly and efficiently to changing environmental conditions. Understanding these regulatory mechanisms can provide insights into bacterial physiology and help inform strategies for controlling bacterial growth and behavior.

Virulence factors are characteristics or components of a microorganism, such as bacteria, viruses, fungi, or parasites, that contribute to its ability to cause damage or disease in a host organism. These factors can include various structures, enzymes, or toxins that allow the pathogen to evade the host's immune system, attach to and invade host tissues, obtain nutrients from the host, or damage host cells directly.

Examples of virulence factors in bacteria include:

1. Endotoxins: lipopolysaccharides found in the outer membrane of Gram-negative bacteria that can trigger a strong immune response and inflammation.
2. Exotoxins: proteins secreted by some bacteria that have toxic effects on host cells, such as botulinum toxin produced by Clostridium botulinum or diphtheria toxin produced by Corynebacterium diphtheriae.
3. Adhesins: structures that help the bacterium attach to host tissues, such as fimbriae or pili in Escherichia coli.
4. Capsules: thick layers of polysaccharides or proteins that surround some bacteria and protect them from the host's immune system, like those found in Streptococcus pneumoniae or Klebsiella pneumoniae.
5. Invasins: proteins that enable bacteria to invade and enter host cells, such as internalins in Listeria monocytogenes.
6. Enzymes: proteins that help bacteria obtain nutrients from the host by breaking down various molecules, like hemolysins that lyse red blood cells to release iron or hyaluronidases that degrade connective tissue.

Understanding virulence factors is crucial for developing effective strategies to prevent and treat infectious diseases caused by these microorganisms.

A consensus sequence in genetics refers to the most common nucleotide (DNA or RNA) or amino acid at each position in a multiple sequence alignment. It is derived by comparing and analyzing several sequences of the same gene or protein from different individuals or organisms. The consensus sequence provides a general pattern or motif that is shared among these sequences and can be useful in identifying functional regions, conserved domains, or evolutionary relationships. However, it's important to note that not every sequence will exactly match the consensus sequence, as variations can occur naturally due to mutations or genetic differences among individuals.

Up-regulation is a term used in molecular biology and medicine to describe an increase in the expression or activity of a gene, protein, or receptor in response to a stimulus. This can occur through various mechanisms such as increased transcription, translation, or reduced degradation of the molecule. Up-regulation can have important functional consequences, for example, enhancing the sensitivity or response of a cell to a hormone, neurotransmitter, or drug. It is a normal physiological process that can also be induced by disease or pharmacological interventions.

Pneumococcal infections are illnesses caused by the bacterium Streptococcus pneumoniae, also known as pneumococcus. This bacterium can infect different parts of the body, including the lungs (pneumonia), blood (bacteremia or sepsis), and the covering of the brain and spinal cord (meningitis). Pneumococcal infections can also cause ear infections and sinus infections. The bacteria spread through close contact with an infected person, who may spread the bacteria by coughing or sneezing. People with weakened immune systems, children under 2 years of age, adults over 65, and those with certain medical conditions are at increased risk for developing pneumococcal infections.

"CBA" is an abbreviation for a specific strain of inbred mice that were developed at the Cancer Research Institute in London. The "Inbred CBA" mice are genetically identical individuals within the same strain, due to many generations of brother-sister matings. This results in a homozygous population, making them valuable tools for research because they reduce variability and increase reproducibility in experimental outcomes.

The CBA strain is known for its susceptibility to certain diseases, such as autoimmune disorders and cancer, which makes it a popular choice for researchers studying those conditions. Additionally, the CBA strain has been widely used in studies related to transplantation immunology, infectious diseases, and genetic research.

It's important to note that while "Inbred CBA" mice are a well-established and useful tool in biomedical research, they represent only one of many inbred strains available for scientific investigation. Each strain has its own unique characteristics and advantages, depending on the specific research question being asked.

Synovial fluid is a viscous, clear, and straw-colored fluid found in the cavities of synovial joints, bursae, and tendon sheaths. It is produced by the synovial membrane, which lines the inner surface of the capsule surrounding these structures.

The primary function of synovial fluid is to reduce friction between articulating surfaces, providing lubrication for smooth and painless movement. It also acts as a shock absorber, protecting the joints from external forces during physical activities. Synovial fluid contains nutrients that nourish the articular cartilage, hyaluronic acid, which provides its viscoelastic properties, and lubricin, a protein responsible for boundary lubrication.

Abnormalities in synovial fluid composition or volume can indicate joint-related disorders, such as osteoarthritis, rheumatoid arthritis, gout, infection, or trauma. Analysis of synovial fluid is often used diagnostically to determine the underlying cause of joint pain, inflammation, or dysfunction.

Meningococcal meningitis is a specific type of bacterial meningitis caused by the bacterium Neisseria meningitidis, also known as meningococcus. Meningitis refers to the inflammation of the meninges, which are the protective membranes covering the brain and spinal cord. When this inflammation is caused by the meningococcal bacteria, it is called meningococcal meningitis.

There are several serogroups of Neisseria meningitidis that can cause invasive disease, with the most common ones being A, B, C, W, and Y. The infection can spread through respiratory droplets or direct contact with an infected person's saliva or secretions, especially when they cough or sneeze.

Meningococcal meningitis is a serious and potentially life-threatening condition that requires immediate medical attention. Symptoms may include sudden onset of fever, severe headache, stiff neck, nausea, vomiting, confusion, and sensitivity to light. In some cases, a rash may also develop, characterized by small purple or red spots that do not blanch when pressed with a glass.

Prevention measures include vaccination against the different serogroups of Neisseria meningitidis, maintaining good personal hygiene, avoiding sharing utensils, cigarettes, or other items that may come into contact with an infected person's saliva, and promptly seeking medical care if symptoms develop.

Staphylococcal Protein A (SpA) is a cell wall-associated protein found on many strains of the bacterium Staphylococcus aureus. It plays an important role in the pathogenesis of staphylococcal infections. SpA has several domains that allow it to bind to various host proteins, including immunoglobulins (Igs), complement components, and fibrinogen.

The protein A's ability to bind to the Fc region of Igs, particularly IgG, enables it to inhibit phagocytosis by masking the antibodies' binding sites, thus helping the bacterium evade the host immune system. Additionally, SpA can activate complement component C1 and initiate the classical complement pathway, leading to the release of anaphylatoxins and the formation of the membrane attack complex, which can cause tissue damage.

Furthermore, SpA's binding to fibrinogen promotes bacterial adherence and colonization of host tissues, contributing to the establishment of infection. Overall, Staphylococcal Protein A is a crucial virulence factor in S. aureus infections, making it an important target for the development of novel therapeutic strategies.

Insertional mutagenesis is a process of introducing new genetic material into an organism's genome at a specific location, which can result in a change or disruption of the function of the gene at that site. This technique is often used in molecular biology research to study gene function and regulation. The introduction of the foreign DNA is typically accomplished through the use of mobile genetic elements, such as transposons or viruses, which are capable of inserting themselves into the genome.

The insertion of the new genetic material can lead to a loss or gain of function in the affected gene, resulting in a mutation. This type of mutagenesis is called "insertional" because the mutation is caused by the insertion of foreign DNA into the genome. The effects of insertional mutagenesis can range from subtle changes in gene expression to the complete inactivation of a gene.

This technique has been widely used in genetic research, including the study of developmental biology, cancer, and genetic diseases. It is also used in the development of genetically modified organisms (GMOs) for agricultural and industrial applications.

Glycosylphosphatidylinositols (GPIs) are complex glycolipids that are attached to the outer leaflet of the cell membrane. They play a role in anchoring proteins to the cell surface by serving as a post-translational modification site for certain proteins, known as GPI-anchored proteins.

The structure of GPIs consists of a core glycan backbone made up of three mannose and one glucosamine residue, which is linked to a phosphatidylinositol (PI) anchor via a glycosylphosphatidylinositol anchor addition site. The PI anchor is composed of a diacylglycerol moiety and a phosphatidylinositol headgroup.

GPIs are involved in various cellular processes, including signal transduction, protein targeting, and cell adhesion. They have also been implicated in several diseases, such as cancer and neurodegenerative disorders.

Single Nucleotide Polymorphism (SNP) is a type of genetic variation that occurs when a single nucleotide (A, T, C, or G) in the DNA sequence is altered. This alteration must occur in at least 1% of the population to be considered a SNP. These variations can help explain why some people are more susceptible to certain diseases than others and can also influence how an individual responds to certain medications. SNPs can serve as biological markers, helping scientists locate genes that are associated with disease. They can also provide information about an individual's ancestry and ethnic background.

Peptide hydrolases, also known as proteases or peptidases, are a group of enzymes that catalyze the hydrolysis of peptide bonds in proteins and peptides. They play a crucial role in various biological processes such as protein degradation, digestion, cell signaling, and regulation of various physiological functions. Based on their catalytic mechanism and the specificity for the peptide bond, they are classified into several types, including serine proteases, cysteine proteases, aspartic proteases, and metalloproteases. These enzymes have important clinical applications in the diagnosis and treatment of various diseases, such as cancer, viral infections, and inflammatory disorders.

"Genetic crosses" refer to the breeding of individuals with different genetic characteristics to produce offspring with specific combinations of traits. This process is commonly used in genetics research to study the inheritance patterns and function of specific genes.

There are several types of genetic crosses, including:

1. Monohybrid cross: A cross between two individuals that differ in the expression of a single gene or trait.
2. Dihybrid cross: A cross between two individuals that differ in the expression of two genes or traits.
3. Backcross: A cross between an individual from a hybrid population and one of its parental lines.
4. Testcross: A cross between an individual with unknown genotype and a homozygous recessive individual.
5. Reciprocal cross: A cross in which the male and female parents are reversed to determine if there is any effect of sex on the expression of the trait.

These genetic crosses help researchers to understand the mode of inheritance, linkage, recombination, and other genetic phenomena.

Endotoxins are toxic substances that are associated with the cell walls of certain types of bacteria. They are released when the bacterial cells die or divide, and can cause a variety of harmful effects in humans and animals. Endotoxins are made up of lipopolysaccharides (LPS), which are complex molecules consisting of a lipid and a polysaccharide component.

Endotoxins are particularly associated with gram-negative bacteria, which have a distinctive cell wall structure that includes an outer membrane containing LPS. These toxins can cause fever, inflammation, and other symptoms when they enter the bloodstream or other tissues of the body. They are also known to play a role in the development of sepsis, a potentially life-threatening condition characterized by a severe immune response to infection.

Endotoxins are resistant to heat, acid, and many disinfectants, making them difficult to eliminate from contaminated environments. They can also be found in a variety of settings, including hospitals, industrial facilities, and agricultural operations, where they can pose a risk to human health.

Fungal antibodies are a type of protein called immunoglobulins that are produced by the immune system in response to the presence of fungi in the body. These antibodies are specifically designed to recognize and bind to antigens on the surface of fungal cells, marking them for destruction by other immune cells.

There are several types of fungal antibodies, including IgA, IgG, IgM, and IgE, each with a specific role in the immune response. For example, IgG antibodies are the most common type of antibody found in the blood and provide long-term immunity to fungi, while IgE antibodies are associated with allergic reactions to fungi.

Fungal antibodies can be measured in the blood or other bodily fluids to help diagnose fungal infections, monitor the effectiveness of treatment, or assess immune function in individuals who are at risk for fungal infections, such as those with weakened immune systems due to HIV/AIDS, cancer, or organ transplantation.

'Arabidopsis' is a genus of small flowering plants that are part of the mustard family (Brassicaceae). The most commonly studied species within this genus is 'Arabidopsis thaliana', which is often used as a model organism in plant biology and genetics research. This plant is native to Eurasia and Africa, and it has a small genome that has been fully sequenced. It is known for its short life cycle, self-fertilization, and ease of growth, making it an ideal subject for studying various aspects of plant biology, including development, metabolism, and response to environmental stresses.

Lactoferrin is a glycoprotein that belongs to the transferrin family. It is an iron-binding protein found in various exocrine secretions such as milk, tears, and saliva, as well as in neutrophils, which are a type of white blood cell involved in immune response. Lactoferrin plays a role in iron homeostasis, antimicrobial activity, and anti-inflammatory responses. It has the ability to bind free iron, which can help prevent bacterial growth by depriving them of an essential nutrient. Additionally, lactoferrin has been shown to have direct antimicrobial effects against various bacteria, viruses, and fungi. Its role in the immune system also includes modulating the activity of immune cells and regulating inflammation.

Peroxidase is a type of enzyme that catalyzes the chemical reaction in which hydrogen peroxide (H2O2) is broken down into water (H2O) and oxygen (O2). This enzymatic reaction also involves the oxidation of various organic and inorganic compounds, which can serve as electron donors.

Peroxidases are widely distributed in nature and can be found in various organisms, including bacteria, fungi, plants, and animals. They play important roles in various biological processes, such as defense against oxidative stress, breakdown of toxic substances, and participation in metabolic pathways.

The peroxidase-catalyzed reaction can be represented by the following chemical equation:

H2O2 + 2e- + 2H+ → 2H2O

In this reaction, hydrogen peroxide is reduced to water, and the electron donor is oxidized. The peroxidase enzyme facilitates the transfer of electrons between the substrate (hydrogen peroxide) and the electron donor, making the reaction more efficient and specific.

Peroxidases have various applications in medicine, industry, and research. For example, they can be used for diagnostic purposes, as biosensors, and in the treatment of wastewater and medical wastes. Additionally, peroxidases are involved in several pathological conditions, such as inflammation, cancer, and neurodegenerative diseases, making them potential targets for therapeutic interventions.

A homozygote is an individual who has inherited the same allele (version of a gene) from both parents and therefore possesses two identical copies of that allele at a specific genetic locus. This can result in either having two dominant alleles (homozygous dominant) or two recessive alleles (homozygous recessive). In contrast, a heterozygote has inherited different alleles from each parent for a particular gene.

The term "homozygote" is used in genetics to describe the genetic makeup of an individual at a specific locus on their chromosomes. Homozygosity can play a significant role in determining an individual's phenotype (observable traits), as having two identical alleles can strengthen the expression of certain characteristics compared to having just one dominant and one recessive allele.

The brain is the central organ of the nervous system, responsible for receiving and processing sensory information, regulating vital functions, and controlling behavior, movement, and cognition. It is divided into several distinct regions, each with specific functions:

1. Cerebrum: The largest part of the brain, responsible for higher cognitive functions such as thinking, learning, memory, language, and perception. It is divided into two hemispheres, each controlling the opposite side of the body.
2. Cerebellum: Located at the back of the brain, it is responsible for coordinating muscle movements, maintaining balance, and fine-tuning motor skills.
3. Brainstem: Connects the cerebrum and cerebellum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure. It also serves as a relay center for sensory information and motor commands between the brain and the rest of the body.
4. Diencephalon: A region that includes the thalamus (a major sensory relay station) and hypothalamus (regulates hormones, temperature, hunger, thirst, and sleep).
5. Limbic system: A group of structures involved in emotional processing, memory formation, and motivation, including the hippocampus, amygdala, and cingulate gyrus.

The brain is composed of billions of interconnected neurons that communicate through electrical and chemical signals. It is protected by the skull and surrounded by three layers of membranes called meninges, as well as cerebrospinal fluid that provides cushioning and nutrients.

Immunologic factors refer to the elements of the immune system that contribute to the body's defense against foreign substances, infectious agents, and cancerous cells. These factors include various types of white blood cells (such as lymphocytes, neutrophils, monocytes, and eosinophils), antibodies, complement proteins, cytokines, and other molecules involved in the immune response.

Immunologic factors can be categorized into two main types: innate immunity and adaptive immunity. Innate immunity is the non-specific defense mechanism that provides immediate protection against pathogens through physical barriers (e.g., skin, mucous membranes), chemical barriers (e.g., stomach acid, enzymes), and inflammatory responses. Adaptive immunity, on the other hand, is a specific defense mechanism that develops over time as the immune system learns to recognize and respond to particular pathogens or antigens.

Abnormalities in immunologic factors can lead to various medical conditions, such as autoimmune disorders, immunodeficiency diseases, and allergies. Therefore, understanding immunologic factors is crucial for diagnosing and treating these conditions.

Brucellosis, bovine is a bacterial infection caused by Brucella abortus that primarily affects cattle. It can also spread to other animals and humans through direct contact with infected animals or ingestion of contaminated food or drink. In animals, it causes abortion, reduced milk production, and weight loss. In humans, it can cause fever, sweats, headaches, joint pain, and weakness. Human infections are rare in countries where milk is pasteurized and proper sanitation measures are in place. It is also known as undulant fever or Malta fever.

Immunological models are simplified representations or simulations of the immune system's structure, function, and interactions with pathogens or other entities. These models can be theoretical (conceptual), mathematical, or computational and are used to understand, explain, and predict immunological phenomena. They help researchers study complex immune processes and responses that cannot be easily observed or manipulated in vivo.

Theoretical immunological models provide conceptual frameworks for understanding immune system behavior, often using diagrams or flowcharts to illustrate interactions between immune components. Mathematical models use mathematical equations to describe immune system dynamics, allowing researchers to simulate and analyze the outcomes of various scenarios. Computational models, also known as in silico models, are created using computer software and can incorporate both theoretical and mathematical concepts to create detailed simulations of immunological processes.

Immunological models are essential tools for advancing our understanding of the immune system and developing new therapies and vaccines. They enable researchers to test hypotheses, explore the implications of different assumptions, and identify areas requiring further investigation.

Neutrophil activation refers to the process by which neutrophils, a type of white blood cell, become activated in response to a signal or stimulus, such as an infection or inflammation. This activation triggers a series of responses within the neutrophil that enable it to carry out its immune functions, including:

1. Degranulation: The release of granules containing enzymes and other proteins that can destroy microbes.
2. Phagocytosis: The engulfment and destruction of microbes through the use of reactive oxygen species (ROS) and other toxic substances.
3. Formation of neutrophil extracellular traps (NETs): A process in which neutrophils release DNA and proteins to trap and kill microbes outside the cell.
4. Release of cytokines and chemokines: Signaling molecules that recruit other immune cells to the site of infection or inflammation.

Neutrophil activation is a critical component of the innate immune response, but excessive or uncontrolled activation can contribute to tissue damage and chronic inflammation.

X-ray crystallography is a technique used in structural biology to determine the three-dimensional arrangement of atoms in a crystal lattice. In this method, a beam of X-rays is directed at a crystal and diffracts, or spreads out, into a pattern of spots called reflections. The intensity and angle of each reflection are measured and used to create an electron density map, which reveals the position and type of atoms in the crystal. This information can be used to determine the molecular structure of a compound, including its shape, size, and chemical bonds. X-ray crystallography is a powerful tool for understanding the structure and function of biological macromolecules such as proteins and nucleic acids.

I'm sorry for any confusion, but "Hemolytic Plaque Technique" is not a widely recognized or established medical term. It seems like it might be a combination of two different concepts in medical and scientific research: the Hemolytic Assay and the Plaque Assay technique.

A Hemolytic Assay is a method used to measure the amount of hemolysis, or the rupturing of red blood cells, caused by a substance such as a toxin or an antibody. This assay can help determine the concentration of the hemolysin in a sample.

On the other hand, the Plaque Assay Technique is a method used to measure the number of infectious virus particles in a sample. It involves adding a layer of cells (like bacteria) that the virus can infect and then covering it with a nutrient agar overlay. After a period of incubation, clear areas or "plaques" appear in the agar where the viruses have infected and lysed the cells. By counting these plaques, researchers can estimate the number of infectious virus particles present in the original sample.

Therefore, if you're looking for a definition of a Hemolytic Plaque Technique, it might refer to a research method that combines both concepts, possibly measuring the amount of a substance (like an antibody) that causes hemolysis in red blood cells and correlating it with the number of infectious virus particles present. However, I would recommend consulting the original source or author for clarification on their intended meaning.

Lupus nephritis is a type of kidney inflammation (nephritis) that can occur in people with systemic lupus erythematosus (SLE), an autoimmune disease. In lupus nephritis, the immune system produces abnormal antibodies that attack the tissues of the kidneys, leading to inflammation and damage. The condition can cause a range of symptoms, including proteinuria (protein in the urine), hematuria (blood in the urine), hypertension (high blood pressure), and eventually kidney failure if left untreated. Lupus nephritis is typically diagnosed through a combination of medical history, physical examination, laboratory tests, and imaging studies. Treatment may include medications to suppress the immune system and control inflammation, such as corticosteroids and immunosuppressive drugs.

Neisseria gonorrhoeae is a species of gram-negative, aerobic diplococcus that is the etiologic agent of gonorrhea, a sexually transmitted infection. It is commonly found in the mucous membranes of the reproductive tract, including the cervix, urethra, and rectum, as well as the throat and eyes. The bacterium can cause a range of symptoms, including discharge, burning during urination, and, in women, abnormal menstrual bleeding. If left untreated, it can lead to more serious complications, such as pelvic inflammatory disease and infertility. It is important to note that N. gonorrhoeae has developed resistance to many antibiotics over time, making treatment more challenging. A culture or nucleic acid amplification test (NAAT) is used for the diagnosis of this infection.

Salmonella is a genus of rod-shaped, Gram-negative bacteria that are facultative anaerobes and are motile due to peritrichous flagella. They are non-spore forming and often have a single polar flagellum when grown in certain conditions. Salmonella species are important pathogens in humans and other animals, causing foodborne illnesses known as salmonellosis.

Salmonella can be found in the intestinal tracts of humans, birds, reptiles, and mammals. They can contaminate various foods, including meat, poultry, eggs, dairy products, and fresh produce. The bacteria can survive and multiply in a wide range of temperatures and environments, making them challenging to control completely.

Salmonella infection typically leads to gastroenteritis, characterized by symptoms such as diarrhea, abdominal cramps, fever, and vomiting. In some cases, the infection may spread beyond the intestines, leading to more severe complications like bacteremia (bacterial infection of the blood) or focal infections in various organs.

There are two main species of Salmonella: S. enterica and S. bongori. S. enterica is further divided into six subspecies and numerous serovars, with over 2,500 distinct serotypes identified to date. Some well-known Salmonella serovars include S. Typhi (causes typhoid fever), S. Paratyphi A, B, and C (cause paratyphoid fever), and S. Enteritidis and S. Typhimurium (common causes of foodborne salmonellosis).

'Candida albicans' is a species of yeast that is commonly found in the human body, particularly in warm and moist areas such as the mouth, gut, and genital region. It is a part of the normal microbiota and usually does not cause any harm. However, under certain conditions like a weakened immune system, prolonged use of antibiotics or steroids, poor oral hygiene, or diabetes, it can overgrow and cause infections known as candidiasis. These infections can affect various parts of the body including the skin, nails, mouth (thrush), and genital area (yeast infection).

The medical definition of 'Candida albicans' is:

A species of yeast belonging to the genus Candida, which is commonly found as a commensal organism in humans. It can cause opportunistic infections when there is a disruption in the normal microbiota or when the immune system is compromised. The overgrowth of C. albicans can lead to various forms of candidiasis, such as oral thrush, vaginal yeast infection, and invasive candidiasis.

Cosmids are a type of cloning vector, which are self-replicating DNA molecules that can be used to introduce foreign DNA fragments into a host organism. Cosmids are plasmids that contain the cos site from bacteriophage λ, allowing them to be packaged into bacteriophage heads during an in vitro packaging reaction. This enables the transfer of large DNA fragments (up to 45 kb) into a host cell through transduction. Cosmids are widely used in molecular biology for the construction and analysis of genomic libraries, physical mapping, and DNA sequencing.

'Coccidioides' is a genus of fungi that are commonly found in the soil in certain geographical areas, including the southwestern United States and parts of Mexico and Central and South America. The two species of this genus, C. immitis and C. posadasii, can cause a serious infection known as coccidioidomycosis (also called Valley Fever) in humans and animals who inhale the spores of the fungi.

The infection typically begins in the lungs and can cause symptoms such as cough, fever, chest pain, fatigue, and weight loss. In some cases, the infection can spread to other parts of the body, leading to more severe and potentially life-threatening complications. People with weakened immune systems, such as those with HIV/AIDS or who are receiving immunosuppressive therapy, are at higher risk for developing severe coccidioidomycosis.

Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a type of bacteria that commonly colonizes the gastrointestinal and genitourinary tracts of humans. It is Gram-positive, facultatively anaerobic, and forms chains when viewed under the microscope.

While S. agalactiae can be carried asymptomatically by many adults, it can cause serious infections in newborns, pregnant women, elderly individuals, and people with weakened immune systems. In newborns, GBS can lead to sepsis, pneumonia, and meningitis, which can result in long-term health complications or even be fatal if left untreated.

Pregnant women are often screened for GBS colonization during the third trimester of pregnancy, and those who test positive may receive intrapartum antibiotics to reduce the risk of transmission to their newborns during delivery.

Immunity, in medical terms, refers to the body's ability to resist or fight against harmful foreign substances or organisms such as bacteria, viruses, parasites, and fungi. This resistance is achieved through various mechanisms, including the production of antibodies, the activation of immune cells like T-cells and B-cells, and the release of cytokines and other chemical messengers that help coordinate the immune response.

There are two main types of immunity: innate immunity and adaptive immunity. Innate immunity is the body's first line of defense against infection and involves nonspecific mechanisms such as physical barriers (e.g., skin and mucous membranes), chemical barriers (e.g., stomach acid and enzymes), and inflammatory responses. Adaptive immunity, on the other hand, is specific to particular pathogens and involves the activation of T-cells and B-cells, which recognize and remember specific antigens (foreign substances that trigger an immune response). This allows the body to mount a more rapid and effective response to subsequent exposures to the same pathogen.

Immunity can be acquired through natural means, such as when a person recovers from an infection and develops immunity to that particular pathogen, or artificially, through vaccination. Vaccines contain weakened or inactivated forms of a pathogen or its components, which stimulate the immune system to produce a response without causing the disease. This response provides protection against future infections with that same pathogen.

'DBA' is an abbreviation for 'Database of Genotypes and Phenotypes,' but in the context of "Inbred DBA mice," it refers to a specific strain of laboratory mice that have been inbred for many generations. The DBA strain is one of the oldest inbred strains, and it was established in 1909 by C.C. Little at the Bussey Institute of Harvard University.

The "Inbred DBA" mice are genetically identical mice that have been produced by brother-sister matings for more than 20 generations. This extensive inbreeding results in a homozygous population, where all members of the strain have the same genetic makeup. The DBA strain is further divided into several sub-strains, including DBA/1, DBA/2, and DBA/J, among others.

DBA mice are known for their black coat color, which can fade to gray with age, and they exhibit a range of phenotypic traits that make them useful for research purposes. For example, DBA mice have a high incidence of retinal degeneration, making them a valuable model for studying eye diseases. They also show differences in behavior, immune response, and susceptibility to various diseases compared to other inbred strains.

In summary, "Inbred DBA" mice are a specific strain of laboratory mice that have been inbred for many generations, resulting in a genetically identical population with distinct phenotypic traits. They are widely used in biomedical research to study various diseases and biological processes.

Phosphatidylinositol Diacylglycerol-Lyase is an enzyme that plays a crucial role in the breakdown and metabolism of certain lipids known as phosphoinositides. These are important components of cell membranes and are involved in various cellular processes such as signal transduction.

The systematic name for this enzyme is 1-phosphatidyl-1D-myo-inositol-3,4-bisphosphate D-3-phosphoinositide phospholipase C. Its function is to cleave 1,2-diacylglycerol and inositol 1,3,4,5-tetrakisphosphate from 1-phosphatidyl-1D-myo-inositol-3,4-bisphosphate. This reaction is a key step in the phosphoinositide signaling pathway, which is involved in regulating various cellular functions such as cell growth, differentiation, and metabolism.

Defects in this enzyme have been associated with certain diseases, including neurological disorders and cancer. Therefore, understanding its function and regulation is an important area of research in biology and medicine.

Northern blotting is a laboratory technique used in molecular biology to detect and analyze specific RNA molecules (such as mRNA) in a mixture of total RNA extracted from cells or tissues. This technique is called "Northern" blotting because it is analogous to the Southern blotting method, which is used for DNA detection.

The Northern blotting procedure involves several steps:

1. Electrophoresis: The total RNA mixture is first separated based on size by running it through an agarose gel using electrical current. This separates the RNA molecules according to their length, with smaller RNA fragments migrating faster than larger ones.

2. Transfer: After electrophoresis, the RNA bands are denatured (made single-stranded) and transferred from the gel onto a nitrocellulose or nylon membrane using a technique called capillary transfer or vacuum blotting. This step ensures that the order and relative positions of the RNA fragments are preserved on the membrane, similar to how they appear in the gel.

3. Cross-linking: The RNA is then chemically cross-linked to the membrane using UV light or heat treatment, which helps to immobilize the RNA onto the membrane and prevent it from washing off during subsequent steps.

4. Prehybridization: Before adding the labeled probe, the membrane is prehybridized in a solution containing blocking agents (such as salmon sperm DNA or yeast tRNA) to minimize non-specific binding of the probe to the membrane.

5. Hybridization: A labeled nucleic acid probe, specific to the RNA of interest, is added to the prehybridization solution and allowed to hybridize (form base pairs) with its complementary RNA sequence on the membrane. The probe can be either a DNA or an RNA molecule, and it is typically labeled with a radioactive isotope (such as ³²P) or a non-radioactive label (such as digoxigenin).

6. Washing: After hybridization, the membrane is washed to remove unbound probe and reduce background noise. The washing conditions (temperature, salt concentration, and detergent concentration) are optimized based on the stringency required for specific hybridization.

7. Detection: The presence of the labeled probe is then detected using an appropriate method, depending on the type of label used. For radioactive probes, this typically involves exposing the membrane to X-ray film or a phosphorimager screen and analyzing the resulting image. For non-radioactive probes, detection can be performed using colorimetric, chemiluminescent, or fluorescent methods.

8. Data analysis: The intensity of the signal is quantified and compared to controls (such as housekeeping genes) to determine the relative expression level of the RNA of interest. This information can be used for various purposes, such as identifying differentially expressed genes in response to a specific treatment or comparing gene expression levels across different samples or conditions.

Cell separation is a process used to separate and isolate specific cell types from a heterogeneous mixture of cells. This can be accomplished through various physical or biological methods, depending on the characteristics of the cells of interest. Some common techniques for cell separation include:

1. Density gradient centrifugation: In this method, a sample containing a mixture of cells is layered onto a density gradient medium and then centrifuged. The cells are separated based on their size, density, and sedimentation rate, with denser cells settling closer to the bottom of the tube and less dense cells remaining near the top.

2. Magnetic-activated cell sorting (MACS): This technique uses magnetic beads coated with antibodies that bind to specific cell surface markers. The labeled cells are then passed through a column placed in a magnetic field, which retains the magnetically labeled cells while allowing unlabeled cells to flow through.

3. Fluorescence-activated cell sorting (FACS): In this method, cells are stained with fluorochrome-conjugated antibodies that recognize specific cell surface or intracellular markers. The stained cells are then passed through a laser beam, which excites the fluorophores and allows for the detection and sorting of individual cells based on their fluorescence profile.

4. Filtration: This simple method relies on the physical size differences between cells to separate them. Cells can be passed through filters with pore sizes that allow smaller cells to pass through while retaining larger cells.

5. Enzymatic digestion: In some cases, cells can be separated by enzymatically dissociating tissues into single-cell suspensions and then using various separation techniques to isolate specific cell types.

These methods are widely used in research and clinical settings for applications such as isolating immune cells, stem cells, or tumor cells from biological samples.

Neutrophil infiltration is a pathological process characterized by the accumulation of neutrophils, a type of white blood cell, in tissue. It is a common feature of inflammation and occurs in response to infection, injury, or other stimuli that trigger an immune response. Neutrophils are attracted to the site of tissue damage by chemical signals called chemokines, which are released by damaged cells and activated immune cells. Once they reach the site of inflammation, neutrophils help to clear away damaged tissue and microorganisms through a process called phagocytosis. However, excessive or prolonged neutrophil infiltration can also contribute to tissue damage and may be associated with various disease states, including cancer, autoimmune disorders, and ischemia-reperfusion injury.

Agglutination tests are laboratory diagnostic procedures used to detect the presence of antibodies or antigens in a sample, such as blood or serum. These tests work by observing the clumping (agglutination) of particles, like red blood cells or bacteriophages, coated with specific antigens or antibodies when mixed with a patient's sample.

In an agglutination test, the sample is typically combined with a reagent containing known antigens or antibodies on the surface of particles, such as latex beads, red blood cells, or bacteriophages. If the sample contains the corresponding antibodies or antigens, they will bind to the particles, forming visible clumps or agglutinates. The presence and strength of agglutination are then assessed visually or with automated equipment to determine the presence and quantity of the target antigen or antibody in the sample.

Agglutination tests are widely used in medical diagnostics for various applications, including:

1. Bacterial and viral infections: To identify specific bacterial or viral antigens in a patient's sample, such as group A Streptococcus, Legionella pneumophila, or HIV.
2. Blood typing: To determine the ABO blood group and Rh type of a donor or recipient before a blood transfusion or organ transplantation.
3. Autoimmune diseases: To detect autoantibodies in patients with suspected autoimmune disorders, such as rheumatoid arthritis, systemic lupus erythematosus, or Hashimoto's thyroiditis.
4. Allergies: To identify specific IgE antibodies in a patient's sample to determine allergic reactions to various substances, such as pollen, food, or venom.
5. Drug monitoring: To detect and quantify the presence of drug-induced antibodies, such as those developed in response to penicillin or hydralazine therapy.

Agglutination tests are simple, rapid, and cost-effective diagnostic tools that provide valuable information for clinical decision-making and patient management. However, they may have limitations, including potential cross-reactivity with other antigens, false-positive results due to rheumatoid factors or heterophile antibodies, and false-negative results due to the prozone effect or insufficient sensitivity. Therefore, it is essential to interpret agglutination test results in conjunction with clinical findings and other laboratory data.

Sensitivity and specificity are statistical measures used to describe the performance of a diagnostic test or screening tool in identifying true positive and true negative results.

* Sensitivity refers to the proportion of people who have a particular condition (true positives) who are correctly identified by the test. It is also known as the "true positive rate" or "recall." A highly sensitive test will identify most or all of the people with the condition, but may also produce more false positives.
* Specificity refers to the proportion of people who do not have a particular condition (true negatives) who are correctly identified by the test. It is also known as the "true negative rate." A highly specific test will identify most or all of the people without the condition, but may also produce more false negatives.

In medical testing, both sensitivity and specificity are important considerations when evaluating a diagnostic test. High sensitivity is desirable for screening tests that aim to identify as many cases of a condition as possible, while high specificity is desirable for confirmatory tests that aim to rule out the condition in people who do not have it.

It's worth noting that sensitivity and specificity are often influenced by factors such as the prevalence of the condition in the population being tested, the threshold used to define a positive result, and the reliability and validity of the test itself. Therefore, it's important to consider these factors when interpreting the results of a diagnostic test.

"Blood physiological phenomena" is a broad term that refers to various functions, processes, and characteristics related to the blood in the body. Here are some definitions of specific blood-related physiological phenomena:

1. Hematopoiesis: The process of producing blood cells in the bone marrow. This includes the production of red blood cells (erythropoiesis), white blood cells (leukopoiesis), and platelets (thrombopoiesis).
2. Hemostasis: The body's response to stop bleeding or prevent excessive blood loss after injury. It involves a complex interplay between blood vessels, platelets, and clotting factors that work together to form a clot.
3. Osmoregulation: The regulation of water and electrolyte balance in the blood. This is achieved through various mechanisms such as thirst, urine concentration, and hormonal control.
4. Acid-base balance: The maintenance of a stable pH level in the blood. This involves the balance between acidic and basic components in the blood, which can be affected by factors such as respiration, metabolism, and kidney function.
5. Hemoglobin function: The ability of hemoglobin molecules in red blood cells to bind and transport oxygen from the lungs to tissues throughout the body.
6. Blood viscosity: The thickness or flowability of blood, which can affect its ability to circulate through the body. Factors that can influence blood viscosity include hematocrit (the percentage of red blood cells in the blood), plasma proteins, and temperature.
7. Immunological function: The role of white blood cells and other components of the immune system in protecting the body against infection and disease. This includes the production of antibodies, phagocytosis (the engulfing and destruction of foreign particles), and inflammation.

Kidney disease, also known as nephropathy or renal disease, refers to any functional or structural damage to the kidneys that impairs their ability to filter blood, regulate electrolytes, produce hormones, and maintain fluid balance. This damage can result from a wide range of causes, including diabetes, hypertension, glomerulonephritis, polycystic kidney disease, lupus, infections, drugs, toxins, and congenital or inherited disorders.

Depending on the severity and progression of the kidney damage, kidney diseases can be classified into two main categories: acute kidney injury (AKI) and chronic kidney disease (CKD). AKI is a sudden and often reversible loss of kidney function that occurs over hours to days, while CKD is a progressive and irreversible decline in kidney function that develops over months or years.

Symptoms of kidney diseases may include edema, proteinuria, hematuria, hypertension, electrolyte imbalances, metabolic acidosis, anemia, and decreased urine output. Treatment options depend on the underlying cause and severity of the disease and may include medications, dietary modifications, dialysis, or kidney transplantation.

Trypanosoma cruzi is a protozoan parasite that causes Chagas disease, also known as American trypanosomiasis. It's transmitted to humans and other mammals through the feces of triatomine bugs, often called "kissing bugs." The parasite can also be spread through contaminated food, drink, or from mother to baby during pregnancy or birth.

The life cycle of Trypanosoma cruzi involves two main forms: the infective metacyclic trypomastigote that is found in the bug's feces and the replicative intracellular amastigote that resides within host cells. The metacyclic trypomastigotes enter the host through mucous membranes or skin lesions, where they invade various types of cells and differentiate into amastigotes. These amastigotes multiply by binary fission and then differentiate back into trypomastigotes, which are released into the bloodstream when the host cell ruptures. The circulating trypomastigotes can then infect other cells or be taken up by another triatomine bug during a blood meal, continuing the life cycle.

Clinical manifestations of Chagas disease range from an acute phase with non-specific symptoms like fever, swelling, and fatigue to a chronic phase characterized by cardiac and gastrointestinal complications, which can develop decades after the initial infection. Early detection and treatment of Chagas disease are crucial for preventing long-term health consequences.

Cellular immunity, also known as cell-mediated immunity, is a type of immune response that involves the activation of immune cells, such as T lymphocytes (T cells), to protect the body against infected or damaged cells. This form of immunity is important for fighting off infections caused by viruses and intracellular bacteria, as well as for recognizing and destroying cancer cells.

Cellular immunity involves a complex series of interactions between various immune cells and molecules. When a pathogen infects a cell, the infected cell displays pieces of the pathogen on its surface in a process called antigen presentation. This attracts T cells, which recognize the antigens and become activated. Activated T cells then release cytokines, chemicals that help coordinate the immune response, and can directly attack and kill infected cells or help activate other immune cells to do so.

Cellular immunity is an important component of the adaptive immune system, which is able to learn and remember specific pathogens in order to mount a faster and more effective response upon subsequent exposure. This form of immunity is also critical for the rejection of transplanted organs, as the immune system recognizes the transplanted tissue as foreign and attacks it.

Anaphylaxis is a severe, life-threatening systemic allergic reaction that occurs suddenly after exposure to an allergen (a substance that triggers an allergic reaction) to which the person has previously been sensitized. The symptoms of anaphylaxis include rapid onset of symptoms such as itching, hives, swelling of the throat and tongue, difficulty breathing, wheezing, cough, chest tightness, rapid heartbeat, hypotension (low blood pressure), shock, and in severe cases, loss of consciousness and death. Anaphylaxis is a medical emergency that requires immediate treatment with epinephrine (adrenaline) and other supportive measures to stabilize the patient's condition.

Proteomics is the large-scale study and analysis of proteins, including their structures, functions, interactions, modifications, and abundance, in a given cell, tissue, or organism. It involves the identification and quantification of all expressed proteins in a biological sample, as well as the characterization of post-translational modifications, protein-protein interactions, and functional pathways. Proteomics can provide valuable insights into various biological processes, diseases, and drug responses, and has applications in basic research, biomedicine, and clinical diagnostics. The field combines various techniques from molecular biology, chemistry, physics, and bioinformatics to study proteins at a systems level.

The Major Histocompatibility Complex (MHC) is a group of cell surface proteins in vertebrates that play a central role in the adaptive immune system. They are responsible for presenting peptide antigens to T-cells, which helps the immune system distinguish between self and non-self. The MHC is divided into two classes:

1. MHC Class I: These proteins present endogenous (intracellular) peptides to CD8+ T-cells (cytotoxic T-cells). The MHC class I molecule consists of a heavy chain and a light chain, together with an antigenic peptide.

2. MHC Class II: These proteins present exogenous (extracellular) peptides to CD4+ T-cells (helper T-cells). The MHC class II molecule is composed of two heavy chains and two light chains, together with an antigenic peptide.

MHC genes are highly polymorphic, meaning there are many different alleles within a population. This diversity allows for better recognition and presentation of various pathogens, leading to a more robust immune response. The term "histocompatibility" refers to the compatibility between donor and recipient MHC molecules in tissue transplantation. Incompatible MHC molecules can lead to rejection of the transplanted tissue due to an activated immune response against the foreign MHC antigens.

Pregnancy is a physiological state or condition where a fertilized egg (zygote) successfully implants and grows in the uterus of a woman, leading to the development of an embryo and finally a fetus. This process typically spans approximately 40 weeks, divided into three trimesters, and culminates in childbirth. Throughout this period, numerous hormonal and physical changes occur to support the growing offspring, including uterine enlargement, breast development, and various maternal adaptations to ensure the fetus's optimal growth and well-being.

"Papio" is a term used in the field of primatology, specifically for a genus of Old World monkeys known as baboons. It's not typically used in human or medical contexts. Baboons are large monkeys with robust bodies and distinctive dog-like faces. They are native to various parts of Africa and are known for their complex social structures and behaviors.

Centrifugation, Density Gradient is a medical laboratory technique used to separate and purify different components of a mixture based on their size, density, and shape. This method involves the use of a centrifuge and a density gradient medium, such as sucrose or cesium chloride, to create a stable density gradient within a column or tube.

The sample is carefully layered onto the top of the gradient and then subjected to high-speed centrifugation. During centrifugation, the particles in the sample move through the gradient based on their size, density, and shape, with heavier particles migrating faster and further than lighter ones. This results in the separation of different components of the mixture into distinct bands or zones within the gradient.

This technique is commonly used to purify and concentrate various types of biological materials, such as viruses, organelles, ribosomes, and subcellular fractions, from complex mixtures. It allows for the isolation of pure and intact particles, which can then be collected and analyzed for further study or use in downstream applications.

In summary, Centrifugation, Density Gradient is a medical laboratory technique used to separate and purify different components of a mixture based on their size, density, and shape using a centrifuge and a density gradient medium.

The Fluorescent Antibody Technique (FAT), Indirect is a type of immunofluorescence assay used to detect the presence of specific antigens in a sample. In this method, the sample is first incubated with a primary antibody that binds to the target antigen. After washing to remove unbound primary antibodies, a secondary fluorescently labeled antibody is added, which recognizes and binds to the primary antibody. This indirect labeling approach allows for amplification of the signal, making it more sensitive than direct methods. The sample is then examined under a fluorescence microscope to visualize the location and amount of antigen based on the emitted light from the fluorescent secondary antibody. It's commonly used in diagnostic laboratories for detection of various bacteria, viruses, and other antigens in clinical specimens.

A cell wall is a rigid layer found surrounding the plasma membrane of plant cells, fungi, and many types of bacteria. It provides structural support and protection to the cell, maintains cell shape, and acts as a barrier against external factors such as chemicals and mechanical stress. The composition of the cell wall varies among different species; for example, in plants, it is primarily made up of cellulose, hemicellulose, and pectin, while in bacteria, it is composed of peptidoglycan.

Immunoblotting, also known as western blotting, is a laboratory technique used in molecular biology and immunogenetics to detect and quantify specific proteins in a complex mixture. This technique combines the electrophoretic separation of proteins by gel electrophoresis with their detection using antibodies that recognize specific epitopes (protein fragments) on the target protein.

The process involves several steps: first, the protein sample is separated based on size through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Next, the separated proteins are transferred onto a nitrocellulose or polyvinylidene fluoride (PVDF) membrane using an electric field. The membrane is then blocked with a blocking agent to prevent non-specific binding of antibodies.

After blocking, the membrane is incubated with a primary antibody that specifically recognizes the target protein. Following this, the membrane is washed to remove unbound primary antibodies and then incubated with a secondary antibody conjugated to an enzyme such as horseradish peroxidase (HRP) or alkaline phosphatase (AP). The enzyme catalyzes a colorimetric or chemiluminescent reaction that allows for the detection of the target protein.

Immunoblotting is widely used in research and clinical settings to study protein expression, post-translational modifications, protein-protein interactions, and disease biomarkers. It provides high specificity and sensitivity, making it a valuable tool for identifying and quantifying proteins in various biological samples.

Ultracentrifugation is a medical and laboratory technique used for the separation of particles of different sizes, densities, or shapes from a mixture based on their sedimentation rates. This process involves the use of a specialized piece of equipment called an ultracentrifuge, which can generate very high centrifugal forces, much greater than those produced by a regular centrifuge.

In ultracentrifugation, a sample is placed in a special tube and spun at extremely high speeds, causing the particles within the sample to separate based on their size, shape, and density. The larger or denser particles will sediment faster and accumulate at the bottom of the tube, while smaller or less dense particles will remain suspended in the solution or sediment more slowly.

Ultracentrifugation is a valuable tool in various fields, including biochemistry, molecular biology, and virology. It can be used to purify and concentrate viruses, subcellular organelles, membrane fractions, ribosomes, DNA, and other macromolecules from complex mixtures. The technique can also provide information about the size, shape, and density of these particles, making it a crucial method for characterizing and studying their properties.

Serologic tests are laboratory tests that detect the presence or absence of antibodies or antigens in a patient's serum (the clear liquid that separates from clotted blood). These tests are commonly used to diagnose infectious diseases, as well as autoimmune disorders and other medical conditions.

In serologic testing for infectious diseases, a sample of the patient's blood is collected and allowed to clot. The serum is then separated from the clot and tested for the presence of antibodies that the body has produced in response to an infection. The test may be used to identify the specific type of infection or to determine whether the infection is active or has resolved.

Serologic tests can also be used to diagnose autoimmune disorders, such as rheumatoid arthritis and lupus, by detecting the presence of antibodies that are directed against the body's own tissues. These tests can help doctors confirm a diagnosis and monitor the progression of the disease.

It is important to note that serologic tests are not always 100% accurate and may produce false positive or false negative results. Therefore, they should be interpreted in conjunction with other clinical findings and laboratory test results.

I must clarify that the term "pedigree" is not typically used in medical definitions. Instead, it is often employed in genetics and breeding, where it refers to the recorded ancestry of an individual or a family, tracing the inheritance of specific traits or diseases. In human genetics, a pedigree can help illustrate the pattern of genetic inheritance in families over multiple generations. However, it is not a medical term with a specific clinical definition.

Chemotaxis is a term used in biology and medicine to describe the movement of an organism or cell towards or away from a chemical stimulus. This process plays a crucial role in various biological phenomena, including immune responses, wound healing, and the development and progression of diseases such as cancer.

In chemotaxis, cells can detect and respond to changes in the concentration of specific chemicals, known as chemoattractants or chemorepellents, in their environment. These chemicals bind to receptors on the cell surface, triggering a series of intracellular signaling events that ultimately lead to changes in the cytoskeleton and directed movement of the cell towards or away from the chemical gradient.

For example, during an immune response, white blood cells called neutrophils use chemotaxis to migrate towards sites of infection or inflammation, where they can attack and destroy invading pathogens. Similarly, cancer cells can use chemotaxis to migrate towards blood vessels and metastasize to other parts of the body.

Understanding chemotaxis is important for developing new therapies and treatments for a variety of diseases, including cancer, infectious diseases, and inflammatory disorders.

A genetic vector is a vehicle, often a plasmid or a virus, that is used to introduce foreign DNA into a host cell as part of genetic engineering or gene therapy techniques. The vector contains the desired gene or genes, along with regulatory elements such as promoters and enhancers, which are needed for the expression of the gene in the target cells.

The choice of vector depends on several factors, including the size of the DNA to be inserted, the type of cell to be targeted, and the efficiency of uptake and expression required. Commonly used vectors include plasmids, adenoviruses, retroviruses, and lentiviruses.

Plasmids are small circular DNA molecules that can replicate independently in bacteria. They are often used as cloning vectors to amplify and manipulate DNA fragments. Adenoviruses are double-stranded DNA viruses that infect a wide range of host cells, including human cells. They are commonly used as gene therapy vectors because they can efficiently transfer genes into both dividing and non-dividing cells.

Retroviruses and lentiviruses are RNA viruses that integrate their genetic material into the host cell's genome. This allows for stable expression of the transgene over time. Lentiviruses, a subclass of retroviruses, have the advantage of being able to infect non-dividing cells, making them useful for gene therapy applications in post-mitotic tissues such as neurons and muscle cells.

Overall, genetic vectors play a crucial role in modern molecular biology and medicine, enabling researchers to study gene function, develop new therapies, and modify organisms for various purposes.

Bacterial adhesion is the initial and crucial step in the process of bacterial colonization, where bacteria attach themselves to a surface or tissue. This process involves specific interactions between bacterial adhesins (proteins, fimbriae, or pili) and host receptors (glycoproteins, glycolipids, or extracellular matrix components). The attachment can be either reversible or irreversible, depending on the strength of interaction. Bacterial adhesion is a significant factor in initiating biofilm formation, which can lead to various infectious diseases and medical device-associated infections.

Genetic variation refers to the differences in DNA sequences among individuals and populations. These variations can result from mutations, genetic recombination, or gene flow between populations. Genetic variation is essential for evolution by providing the raw material upon which natural selection acts. It can occur within a single gene, between different genes, or at larger scales, such as differences in the number of chromosomes or entire sets of chromosomes. The study of genetic variation is crucial in understanding the genetic basis of diseases and traits, as well as the evolutionary history and relationships among species.

'Mice, Inbred MRL-lpr' refers to a specific strain of laboratory mice that are used in biomedical research. The 'MRL' part of the name stands for the breeding colony where they were originally developed, which is the Mouse Repository at the Jackson Laboratory in Bar Harbor, Maine. The 'lpr' designation indicates that these mice carry a mutation in the Fas gene, also known as lpr (lymphoproliferation) gene, which leads to an autoimmune disorder characterized by lymphadenopathy (enlarged lymph nodes), splenomegaly (enlarged spleen), and production of autoantibodies.

The MRL-lpr mice are known for their accelerated aging phenotype, which includes the development of a variety of age-related diseases such as atherosclerosis, osteoporosis, and cancer. They also develop a severe form of systemic lupus erythematosus (SLE), an autoimmune disease that affects many organs in the body. The MRL-lpr mice are widely used as a model to study the pathogenesis of SLE and other autoimmune diseases, as well as to test potential therapies for these conditions.

It is important to note that while inbred mouse strains like MRL-lpr provide valuable insights into human disease mechanisms, they do not perfectly replicate all aspects of human disease, and results obtained in mice may not always translate directly to humans. Therefore, findings from mouse studies should be interpreted with caution and validated in human studies before being applied in clinical practice.

A conserved sequence in the context of molecular biology refers to a pattern of nucleotides (in DNA or RNA) or amino acids (in proteins) that has remained relatively unchanged over evolutionary time. These sequences are often functionally important and are highly conserved across different species, indicating strong selection pressure against changes in these regions.

In the case of protein-coding genes, the corresponding amino acid sequence is deduced from the DNA sequence through the genetic code. Conserved sequences in proteins may indicate structurally or functionally important regions, such as active sites or binding sites, that are critical for the protein's activity. Similarly, conserved non-coding sequences in DNA may represent regulatory elements that control gene expression.

Identifying conserved sequences can be useful for inferring evolutionary relationships between species and for predicting the function of unknown genes or proteins.

Glycosylation is the enzymatic process of adding a sugar group, or glycan, to a protein, lipid, or other organic molecule. This post-translational modification plays a crucial role in modulating various biological functions, such as protein stability, trafficking, and ligand binding. The structure and composition of the attached glycans can significantly influence the functional properties of the modified molecule, contributing to cell-cell recognition, signal transduction, and immune response regulation. Abnormal glycosylation patterns have been implicated in several disease states, including cancer, diabetes, and neurodegenerative disorders.

Disease susceptibility, also known as genetic predisposition or genetic susceptibility, refers to the increased likelihood or risk of developing a particular disease due to inheriting specific genetic variations or mutations. These genetic factors can make an individual more vulnerable to certain diseases compared to those who do not have these genetic changes.

It is important to note that having a genetic predisposition does not guarantee that a person will definitely develop the disease. Other factors, such as environmental exposures, lifestyle choices, and additional genetic variations, can influence whether or not the disease will manifest. In some cases, early detection and intervention may help reduce the risk or delay the onset of the disease in individuals with a known genetic susceptibility.

Nucleic acid hybridization is a process in molecular biology where two single-stranded nucleic acids (DNA, RNA) with complementary sequences pair together to form a double-stranded molecule through hydrogen bonding. The strands can be from the same type of nucleic acid or different types (i.e., DNA-RNA or DNA-cDNA). This process is commonly used in various laboratory techniques, such as Southern blotting, Northern blotting, polymerase chain reaction (PCR), and microarray analysis, to detect, isolate, and analyze specific nucleic acid sequences. The hybridization temperature and conditions are critical to ensure the specificity of the interaction between the two strands.

Sialic acids are a family of nine-carbon sugars that are commonly found on the outermost surface of many cell types, particularly on the glycoconjugates of mucins in various secretions and on the glycoproteins and glycolipids of cell membranes. They play important roles in a variety of biological processes, including cell recognition, immune response, and viral and bacterial infectivity. Sialic acids can exist in different forms, with N-acetylneuraminic acid being the most common one in humans.

'Tumor cells, cultured' refers to the process of removing cancerous cells from a tumor and growing them in controlled laboratory conditions. This is typically done by isolating the tumor cells from a patient's tissue sample, then placing them in a nutrient-rich environment that promotes their growth and multiplication.

The resulting cultured tumor cells can be used for various research purposes, including the study of cancer biology, drug development, and toxicity testing. They provide a valuable tool for researchers to better understand the behavior and characteristics of cancer cells outside of the human body, which can lead to the development of more effective cancer treatments.

It is important to note that cultured tumor cells may not always behave exactly the same way as they do in the human body, so findings from cell culture studies must be validated through further research, such as animal models or clinical trials.

An amino acid substitution is a type of mutation in which one amino acid in a protein is replaced by another. This occurs when there is a change in the DNA sequence that codes for a particular amino acid in a protein. The genetic code is redundant, meaning that most amino acids are encoded by more than one codon (a sequence of three nucleotides). As a result, a single base pair change in the DNA sequence may not necessarily lead to an amino acid substitution. However, if a change does occur, it can have a variety of effects on the protein's structure and function, depending on the nature of the substituted amino acids. Some substitutions may be harmless, while others may alter the protein's activity or stability, leading to disease.

Hemolytic anemia, autoimmune is a type of anemia characterized by the premature destruction of red blood cells (RBCs) in which the immune system mistakenly attacks and destroys its own RBCs. This occurs when the body produces autoantibodies that bind to the surface of RBCs, leading to their rupture (hemolysis). The symptoms may include fatigue, weakness, shortness of breath, and dark colored urine. The diagnosis is made through blood tests that measure the number and size of RBCs, reticulocyte count, and the presence of autoantibodies. Treatment typically involves suppressing the immune system with medications such as corticosteroids or immunosuppressive drugs, and sometimes removal of the spleen (splenectomy) may be necessary.

Genetic transformation is the process by which an organism's genetic material is altered or modified, typically through the introduction of foreign DNA. This can be achieved through various techniques such as:

* Gene transfer using vectors like plasmids, phages, or artificial chromosomes
* Direct uptake of naked DNA using methods like electroporation or chemically-mediated transfection
* Use of genome editing tools like CRISPR-Cas9 to introduce precise changes into the organism's genome.

The introduced DNA may come from another individual of the same species (cisgenic), from a different species (transgenic), or even be synthetically designed. The goal of genetic transformation is often to introduce new traits, functions, or characteristics that do not exist naturally in the organism, or to correct genetic defects.

This technique has broad applications in various fields, including molecular biology, biotechnology, and medical research, where it can be used to study gene function, develop genetically modified organisms (GMOs), create cell lines for drug screening, and even potentially treat genetic diseases through gene therapy.

Blood protein disorders refer to a group of medical conditions that affect the production or function of proteins in the blood. These proteins are crucial for maintaining the proper functioning of the body's immune system, transporting nutrients, and preventing excessive bleeding. Some examples of blood protein disorders include:

1. Hemophilia: A genetic disorder caused by a deficiency or absence of clotting factors in the blood, leading to prolonged bleeding and poor clot formation.
2. Von Willebrand disease: A genetic disorder characterized by abnormal or deficient von Willebrand factor, which is necessary for platelet function and proper clotting.
3. Dysproteinemias: Abnormal levels of certain proteins in the blood, such as immunoglobulins (antibodies) or paraproteins, which can indicate underlying conditions like multiple myeloma or macroglobulinemia.
4. Hypoproteinemia: Low levels of total protein in the blood, often caused by liver disease, malnutrition, or kidney disease.
5. Hyperproteinemia: Elevated levels of total protein in the blood, which can be caused by dehydration, inflammation, or certain types of cancer.
6. Hemoglobinopathies: Genetic disorders affecting the structure and function of hemoglobin, a protein found in red blood cells that carries oxygen throughout the body. Examples include sickle cell anemia and thalassemia.
7. Disorders of complement proteins: Abnormalities in the complement system, which is a group of proteins involved in the immune response, can lead to conditions like autoimmune disorders or recurrent infections.

Treatment for blood protein disorders varies depending on the specific condition and its severity but may include medications, transfusions, or other medical interventions.

Histoplasmin is not a medical condition or diagnosis itself, but it's a term related to a skin test used in medicine. Histoplasmin is an antigen extract derived from the histoplasmoma (a form of the fungus Histoplasma capsulatum) used in the histoplasmin skin test. This test is utilized to determine whether a person has been infected with the histoplasmosis fungus, which causes the disease histoplasmosis.

The histoplasmin skin test involves injecting a small amount of histoplasmin under the surface of the skin, usually on the forearm. If the person has previously been exposed to Histoplasma capsulatum, their immune system will recognize the antigen and produce a reaction (a hard, red, swollen area) at the injection site within 24-72 hours. The size of this reaction helps healthcare professionals determine if the person has developed an immune response to the fungus, indicating past or current infection with histoplasmosis.

It's important to note that a positive histoplasmin skin test does not necessarily mean that the person is currently sick with histoplasmosis. Instead, it shows that they have been exposed to the fungus at some point in their life and have developed an immune response to it.

A haplotype is a group of genes or DNA sequences that are inherited together from a single parent. It refers to a combination of alleles (variant forms of a gene) that are located on the same chromosome and are usually transmitted as a unit. Haplotypes can be useful in tracing genetic ancestry, understanding the genetic basis of diseases, and developing personalized medical treatments.

In population genetics, haplotypes are often used to study patterns of genetic variation within and between populations. By comparing haplotype frequencies across populations, researchers can infer historical events such as migrations, population expansions, and bottlenecks. Additionally, haplotypes can provide information about the evolutionary history of genes and genomic regions.

In clinical genetics, haplotypes can be used to identify genetic risk factors for diseases or to predict an individual's response to certain medications. For example, specific haplotypes in the HLA gene region have been associated with increased susceptibility to certain autoimmune diseases, while other haplotypes in the CYP450 gene family can affect how individuals metabolize drugs.

Overall, haplotypes provide a powerful tool for understanding the genetic basis of complex traits and diseases, as well as for developing personalized medical treatments based on an individual's genetic makeup.

In the context of medicine, plasma refers to the clear, yellowish fluid that is the liquid component of blood. It's composed of water, enzymes, hormones, antibodies, clotting factors, and other proteins. Plasma serves as a transport medium for cells, nutrients, waste products, gases, and other substances throughout the body. Additionally, it plays a crucial role in the immune response and helps regulate various bodily functions.

Plasma can be collected from blood donors and processed into various therapeutic products, such as clotting factors for people with hemophilia or immunoglobulins for patients with immune deficiencies. This process is called plasma fractionation.

An acute disease is a medical condition that has a rapid onset, develops quickly, and tends to be short in duration. Acute diseases can range from minor illnesses such as a common cold or flu, to more severe conditions such as pneumonia, meningitis, or a heart attack. These types of diseases often have clear symptoms that are easy to identify, and they may require immediate medical attention or treatment.

Acute diseases are typically caused by an external agent or factor, such as a bacterial or viral infection, a toxin, or an injury. They can also be the result of a sudden worsening of an existing chronic condition. In general, acute diseases are distinct from chronic diseases, which are long-term medical conditions that develop slowly over time and may require ongoing management and treatment.

Examples of acute diseases include:

* Acute bronchitis: a sudden inflammation of the airways in the lungs, often caused by a viral infection.
* Appendicitis: an inflammation of the appendix that can cause severe pain and requires surgical removal.
* Gastroenteritis: an inflammation of the stomach and intestines, often caused by a viral or bacterial infection.
* Migraine headaches: intense headaches that can last for hours or days, and are often accompanied by nausea, vomiting, and sensitivity to light and sound.
* Myocardial infarction (heart attack): a sudden blockage of blood flow to the heart muscle, often caused by a buildup of plaque in the coronary arteries.
* Pneumonia: an infection of the lungs that can cause coughing, chest pain, and difficulty breathing.
* Sinusitis: an inflammation of the sinuses, often caused by a viral or bacterial infection.

It's important to note that while some acute diseases may resolve on their own with rest and supportive care, others may require medical intervention or treatment to prevent complications and promote recovery. If you are experiencing symptoms of an acute disease, it is always best to seek medical attention to ensure proper diagnosis and treatment.

Karyotyping is a medical laboratory test used to study the chromosomes in a cell. It involves obtaining a sample of cells from a patient, usually from blood or bone marrow, and then staining the chromosomes so they can be easily seen under a microscope. The chromosomes are then arranged in pairs based on their size, shape, and other features to create a karyotype. This visual representation allows for the identification and analysis of any chromosomal abnormalities, such as extra or missing chromosomes, or structural changes like translocations or inversions. These abnormalities can provide important information about genetic disorders, diseases, and developmental problems.

Exudates and transudates are two types of bodily fluids that can accumulate in various body cavities or tissues as a result of injury, inflammation, or other medical conditions. Here are the medical definitions:

1. Exudates: These are fluids that accumulate due to an active inflammatory process. Exudates contain high levels of protein, white blood cells (such as neutrophils and macrophages), and sometimes other cells like red blood cells or cellular debris. They can be yellow, green, or brown in color and may have a foul odor due to the presence of dead cells and bacteria. Exudates are often seen in conditions such as abscesses, pneumonia, pleurisy, or wound infections.

Examples of exudative fluids include pus, purulent discharge, or inflammatory effusions.

2. Transudates: These are fluids that accumulate due to increased hydrostatic pressure or decreased oncotic pressure within the blood vessels. Transudates contain low levels of protein and cells compared to exudates. They are typically clear and pale yellow in color, with no odor. Transudates can be found in conditions such as congestive heart failure, liver cirrhosis, or nephrotic syndrome.

Examples of transudative fluids include ascites, pleural effusions, or pericardial effusions.

It is essential to differentiate between exudates and transudates because their underlying causes and treatment approaches may differ significantly. Medical professionals often use various tests, such as fluid analysis, to determine whether a fluid sample is an exudate or transudate.

The endothelium is a thin layer of simple squamous epithelial cells that lines the interior surface of blood vessels, lymphatic vessels, and heart chambers. The vascular endothelium, specifically, refers to the endothelial cells that line the blood vessels. These cells play a crucial role in maintaining vascular homeostasis by regulating vasomotor tone, coagulation, platelet activation, inflammation, and permeability of the vessel wall. They also contribute to the growth and repair of the vascular system and are involved in various pathological processes such as atherosclerosis, hypertension, and diabetes.

Microbial viability is the ability of a microorganism to grow, reproduce and maintain its essential life functions. It can be determined through various methods such as cell growth in culture media, staining techniques that detect metabolic activity, or direct observation of active movement. In contrast, non-viable microorganisms are those that have been killed or inactivated and cannot replicate or cause further harm. The measurement of microbial viability is important in various fields such as medicine, food safety, water quality, and environmental monitoring to assess the effectiveness of disinfection and sterilization procedures, and to determine the presence and concentration of harmful bacteria in different environments.

Tumor Necrosis Factor-alpha (TNF-α) is a cytokine, a type of small signaling protein involved in immune response and inflammation. It is primarily produced by activated macrophages, although other cell types such as T-cells, natural killer cells, and mast cells can also produce it.

TNF-α plays a crucial role in the body's defense against infection and tissue injury by mediating inflammatory responses, activating immune cells, and inducing apoptosis (programmed cell death) in certain types of cells. It does this by binding to its receptors, TNFR1 and TNFR2, which are found on the surface of many cell types.

In addition to its role in the immune response, TNF-α has been implicated in the pathogenesis of several diseases, including autoimmune disorders such as rheumatoid arthritis, inflammatory bowel disease, and psoriasis, as well as cancer, where it can promote tumor growth and metastasis.

Therapeutic agents that target TNF-α, such as infliximab, adalimumab, and etanercept, have been developed to treat these conditions. However, these drugs can also increase the risk of infections and other side effects, so their use must be carefully monitored.

Mannose is a simple sugar (monosaccharide) that is similar in structure to glucose. It is a hexose, meaning it contains six carbon atoms. Mannose is a stereoisomer of glucose, meaning it has the same chemical formula but a different structural arrangement of its atoms.

Mannose is not as commonly found in foods as other simple sugars, but it can be found in some fruits, such as cranberries, blueberries, and peaches, as well as in certain vegetables, like sweet potatoes and turnips. It is also found in some dietary fibers, such as those found in beans and whole grains.

In the body, mannose can be metabolized and used for energy, but it is also an important component of various glycoproteins and glycolipids, which are molecules that play critical roles in many biological processes, including cell recognition, signaling, and adhesion.

Mannose has been studied as a potential therapeutic agent for various medical conditions, including urinary tract infections (UTIs), because it can inhibit the attachment of certain bacteria to the cells lining the urinary tract. Additionally, mannose-binding lectins have been investigated for their potential role in the immune response to viral and bacterial infections.

Sepharose is not a medical term itself, but it is a trade name for a type of gel that is often used in medical and laboratory settings. Sepharose is a type of cross-linked agarose gel, which is derived from seaweed. It is commonly used in chromatography, a technique used to separate and purify different components of a mixture based on their physical or chemical properties.

Sepharose gels are available in various forms, including beads and sheets, and they come in different sizes and degrees of cross-linking. These variations allow for the separation and purification of molecules with different sizes, charges, and other properties. Sepharose is known for its high porosity, mechanical stability, and low non-specific binding, making it a popular choice for many laboratory applications.

Hereditary angioedema (HAE) is a rare genetic disorder characterized by recurrent episodes of swelling in various parts of the body, including the face, lips, tongue, throat, hands, feet, and/or genitals. The swelling can also affect the gastrointestinal tract, causing abdominal pain, nausea, vomiting, and diarrhea.

HAE is caused by a deficiency or dysfunction of the C1 inhibitor protein, which is a part of the body's immune system that helps regulate inflammation and blood vessel dilation. As a result, people with HAE have uncontrolled activation of the complement system and increased levels of bradykinin, a potent vasodilator that causes the characteristic swelling.

There are three types of HAE: type I, type II, and type III. Type I and type II are caused by mutations in the gene that codes for the C1 inhibitor protein, resulting in low levels or dysfunctional C1 inhibitor protein. Type III is caused by a mutation in the coagulation factor XII gene, leading to overactivation of the contact system and increased bradykinin production.

HAE is an inherited disorder, typically passed down from parent to child in an autosomal dominant pattern. This means that a person has a 50% chance of inheriting the mutated gene from an affected parent and developing HAE. However, up to 25% of cases may occur spontaneously due to new mutations in the gene.

Treatment for HAE includes medications to prevent or reduce the severity and frequency of attacks, such as C1 inhibitor replacement therapy, attenuated androgens, and monoclonal antibodies against kallikrein. In addition, acute attacks can be treated with on-demand therapies, such as plasma-derived C1 inhibitor, icatibant, and ecallantide.

"Mycoplasma pulmonis" is a species of bacteria that belongs to the genus Mycoplasma, which are characterized as the smallest free-living organisms. "M. pulmonis" is known to primarily infect rodents, particularly mice and rats, causing respiratory diseases. It colonizes the upper and lower respiratory tract, leading to conditions such as murine respiratory mycoplasmosis (MRM).

The bacteria lack a cell wall, which makes them resistant to many antibiotics that target cell wall synthesis. They can cause chronic inflammation and damage to the respiratory system, including airway obstruction, bronchiolitis, and alveolitis. Transmission of "M. pulmonis" typically occurs through direct contact with infected animals or their aerosolized secretions.

It is important to note that "Mycoplasma pulmonis" does not infect humans and is primarily a research model for studying bacterial respiratory infections and host immune responses.

Mass spectrometry (MS) is an analytical technique used to identify and quantify the chemical components of a mixture or compound. It works by ionizing the sample, generating charged molecules or fragments, and then measuring their mass-to-charge ratio in a vacuum. The resulting mass spectrum provides information about the molecular weight and structure of the analytes, allowing for identification and characterization.

In simpler terms, mass spectrometry is a method used to determine what chemicals are present in a sample and in what quantities, by converting the chemicals into ions, measuring their masses, and generating a spectrum that shows the relative abundances of each ion type.

Furthermore, BacMam viruses are inactivated by human complement, which reduces risk to researchers. Lastly, viruses used in the ... Baculoviruses are Risk Group 1 agents that have been widely used for over 25 years for insect cell protein production ... "Baculovirus-mediated gene transfer in the presence of human serum or blood facilitated by inhibition of the complement system ...
... immunosuppressive agents MeSH D27.505.696.477.656.500 - complement inactivating agents MeSH D27.505.696.477.656.750 - ... antiviral agents MeSH D27.505.954.122.388.077 - anti-retroviral agents MeSH D27.505.954.122.388.077.088 - anti-hiv agents MeSH ... tocolytic agents MeSH D27.505.954.016 - anti-allergic agents MeSH D27.505.954.122 - anti-infective agents MeSH D27.505.954.122. ... tranquilizing agents MeSH D27.505.696.277.950.015 - anti-anxiety agents MeSH D27.505.696.277.950.025 - antimanic agents MeSH ...
Very Heavy on 28 March 1944 Inactivated on 1 April 1944 Activated on 1 April 1944 Inactivated on 27 December 1945. Redesignated ... These facilities complement the area's cooperative weather, sparsely populated terrain and uncongested airspace. Pilots fly ... The 425th Air Base Squadron provides mission and administrative agent support to US personnel assigned to NATO HQ Allied Land ... Inactivated on 1 April 1944 with the end of heavy bomber training. Reactivated the same day at Smoky Hill Army Airfield, Kansas ...
Importantly, RNA integrity is maintained by inactivating RNases with chaotropic agents such as guanidinium isothiocyanate, ... mRNA is selectively reverse transcribed using oligo-dT primers that are the reverse complement of the poly-adenylated tail on ...
Combining ABT-737 with second agents that inactivate Mcl-1 may reduce this effect. ABT-737 has demonstrated single-agent ... and natural killer cells to destroy the targeted cells Complement-dependent cytotoxicity (CDC)-- Initiates the complement ... Cell death does not appear to be mediated by complement, but modest antibody-dependent cellular cytotoxicity and direct killing ... Reduced susceptibility to apoptosis increases the resistance of cancer cells to radiation and cytotoxic agents. B-cell lymphoma ...
Studies began to look for the possible species that acted as reservoirs for the virus and the agents responsible for ... The vaccine for KFDV consists of formalin-inactivated KFDV. The vaccine has a 62.4% effectiveness rate for individuals who ... Other methods of diagnosis included hemagglutination inhibition (HI), complement fixation, neutralization tests. However, new ...
First, the catalog of infectious agents has grown to the point that virtually all of the significant infectious agents of the ... This process requires immune mechanisms to kill or inactivate the inoculum of the pathogen. Specific acquired immunity against ... such as antibody-initiated complement-dependent bacteriolysis, opsonoization, phagocytosis and killing, as occurs for some ... Second, an infectious agent must grow within the human body to cause disease; essentially it must amplify its own nucleic acids ...
"Janssen's Single-Agent Darzalex (daratumumab) Approved by European Commission for Treatment of Multiple Myeloma (MM)". 23 May ... Daratumumab binds to CD38, causing cells to apoptose via antibody-dependent cellular cytotoxicity, complement-dependent ... DTT also inactivates/destroys many antigens on the red blood cell surface by disrupting disulfide bonds. The only antigen ... Updated trial results presented in December 2012, indicate daratumumab is continuing to show promising single-agent anti- ...
... binds to target cells by the complement receptor 3 (CD11b/CD18, or Mac-1). Target cell are therefore ... Together with the pertussis toxin it is the most important virulence factor of the causative agent of whooping cough, ... Besides attachment to bacterial proteins, aggregation also inactivates the toxin. This quick inactivation highlights the ...
Hence, the classic inflammatory response was viewed as fully regulated by the soluble signaling agents. That is, the agents ... complement components C5a and C3a which are chemotactic factors formed during the activation of the host's blood complement ... However, studies suggest that synthetic SPM that are resistant to being metabolically inactivated hold promise of being ... While initially found to have in vitro activity suggesting that they might act as pro-inflammatory agents, Serhan and ...
Tissue plasminogen activator (t-PA) and urokinase are the agents that convert plasminogen to the active plasmin, thus allowing ... Plasmin, in addition to lysing fibrin clots, also cleaves the complement system component C3, and fibrin degradation products ... α2-Antiplasmin and α2-macroglobulin inactivate plasmin. Plasmin activity is also reduced by thrombin-activatable fibrinolysis ... Thrombolysis refers to the dissolution of the thrombus due to various agents while fibrinolysis refers specifically to the ...
Its causative agent is lymphocytic choriomeningitis mammarenavirus (LCMV), a member of the family Arenaviridae. The name was ... However, some authors note that such complement-fixation tests are insensitive and should not be used for diagnosis. Dr. Clare ... In addition, LCMV can also be inactivated by heat, ultraviolet light or gamma irradiation. Studies have indicated that human ... Such agents had been developed in the animal care facility, which periodically screened sentinel animals for extraneous ...
becoming the first approved oncolytic agent in the western world. It is based on herpes simplex virus (HSV-1). It has also been ... Although it poses a hurdle by inactivating viruses, the patient's immune system can also act as an ally against tumors; ... Magge D, Guo ZS, O'Malley ME, Francis L, Ravindranathan R, Bartlett DL (June 2013). "Inhibitors of C5 complement enhance ... Directed evolution was applied on human adenovirus, one of many viruses that are being developed as oncolytic agents, to create ...
Li W, Qin L, Feng R, Hu G, Sun H, He Y, Zhang R (July 2019). "Emerging senolytic agents derived from natural products". ... Additionally, several types of ubiquitination events parallel and complement the galectin-driven processes: Ubiquitination of ... of the autophagy systems listed above and further inactivates mTORC1, allows for strong autophagy induction and autophagic ... mTOR is inhibited when lysosomal membrane is damaged by various exogenous or endogenous agents, such as invading bacteria, ...
... s have the ability to metabolize, detoxify, and inactivate exogenous compounds such as drugs (see drug metabolism), ... in which calcium is removed to disrupt cell-cell tight junctions by the use of a calcium chelating agent. Next, a solution ... complement, and glycoproteins. Hepatocytes manufacture their own structural proteins and intracellular enzymes. Synthesis of ... "Wheat extracts as an efficient cryoprotective agent for primary cultures of rat hepatocytes". Biotechnology and Bioengineering ...
The human genome already contains remnants of retroviral genomes that have been inactivated and harnessed for self-gain. Indeed ... This prevents infection by effectively destroying the foreign DNA introduced by an infectious agent (such as a bacteriophage). ... and excision repair cross complementing 1 (ERCC) appear to mimic the action of RM-systems in bacteria, and the non-homologous ... gene transfer agents or generalized transduction in order to move between genomes.[citation needed] Methylation Restriction ...
Next, we try to determine if we can block protein function by treating AB9 with pharmacological agents. The inhibitor in this ... heat inactivated FBS and antibiotics-antimycotics. The cells were then placed poly-L-lysine coverglass and allowing it to grow ... "The zebrafish fibroblast cell line AB9 as a tool to complement gene regulation studies". Musculoskeletal Regeneration. 1. ... "The zebrafish fibroblast cell line AB9 as a tool to complement gene regulation studies". Musculoskeletal Regeneration. 1. ( ...
... as the electrophilic properties of glutathione allow it to react with cytotoxic agents, inactivating them. In some cases, ... The cisplatin-resistant cells upregulate expression of the excision repair cross-complementing (ERCC1) gene and protein. Some ... In colorectal cancer cells, inhibition of NF-κB or MDR1 caused increased apoptosis in response to a chemotherapeutic agent. ... 2004-07-15). "Oncogenic H-Ras Up-Regulates Expression of ERCC1 to Protect Cells from Platinum-Based Anticancer Agents". Cancer ...
These agents increase the level of aminopeptidase P, an enzyme that inactivates kinins; kinins (especially bradykinin) are ... All forms of HAE lead to abnormal activation of the complement system, and all forms can cause swelling elsewhere in the body, ... In this analysis, it is usually a reduced complement factor C4, rather than the C1-INH deficiency itself, that is detected. The ... The version related to histamine is due to an allergic reaction to agents such as insect bites, foods, or medications. The ...
Note below that PARP is inactivated by caspase-3 cleavage during programmed cell death. PARP enzymes are essential in a number ... DNA damage theory of aging Maximum life span PARP1 PARP inhibitor class of anti-cancer agents Parthanatos Senescence Herceg Z, ... and scaffolding proteins such as X-ray cross-complementing gene 1 (XRCC1). After repairing, the PAR chains are degraded via ... Cleavage of PARP, by enzymes such as caspases or cathepsins, typically inactivates PARP. The size of the cleavage fragments can ...
A causative agent may not be isolated in about half of cases despite careful testing. In an active population-based ... In the lower airways, reflexes of the glottis, actions of complement proteins and immunoglobulins are important for protection ... attempt to inactivate the bacteria. The neutrophils also release cytokines, causing a general activation of the immune system. ... The causative agent is determined in only 15% of cases with routine microbiological tests. Pneumonitis refers to lung ...
As LF is the agent responsible for the death of infected hosts, it is classified in the group of lethal toxins. Diphtheria ... The diphtheria vaccine contains a diphtheria toxoid, antigenically identical yet inactivated and non-toxic. When the toxoid is ... complement and neutrophils. These secreted virulence factors assist the bacterium in surviving immune response mechanisms. ... Mycotoxins can also play a role in chemical warfare agents, CWA, which are chemicals that contain toxins that are used to cause ...
Rather than introducing an inactivated or attenuated micro-organism to an immune system (which would constitute a "whole-agent ... Meri S, Jördens M, Jarva H (December 2008). "Microbial complement inhibitors as vaccines". Vaccine. 26 (Suppl 8): I113-117. doi ... The agent stimulates the body's immune system to recognize the agent as a threat, destroy it, and recognize further and destroy ... When the virulent version of an agent is encountered, the body recognizes the protein coat on the agent, and thus is prepared ...
The squadrons flew agents and supplies into southern France with B-24 Liberators that had all armament removed except in the ... When assigned to Harrington, the 801st Bombardment Group (Provisional) was inactivated in a name-only manner. Headquarters and ... HHS 39th Service Group 18th Weather Squadron 35th Station Complement Squadron Regular Army Station Units included: Headquarters ... However, the Japanese surrender canceled those plans and the Group was inactivated in October. After the war, Harrington ...
The M-protein aids in immune evasion by inhibiting phagocytosis and inactivating the complement system. Furthermore, ... Second-line agents include macrolides and clindamycin, although increasing resistance, due to both efflux and target ... Antimicrobial Agents and Chemotherapy. 19 (5): 716-725. doi:10.1128/aac.19.5.716. ISSN 0066-4804. PMC 181512. PMID 7027921. ...
intercalating agent Any chemical compound (e.g. ethidium bromide) that disrupts the alignment and pairing of bases in the ... genome The entire complement of genetic material contained within the chromosomes of an organism, organelle, or virus. The term ... back mutation A mutation that reverses the effect of a previous mutation which had inactivated a gene, thus restoring wild-type ... genotype The entire complement of alleles present in a particular individual's genome, which gives rise to the individual's ...
Agents Chemother. 49 (1): 269-75. doi:10.1128/AAC.49.1.269-275.2005. PMC 538877. PMID 15616305. Vordenbäumen, S; Sander, O; ... The mechanism(s) by which microorganisms are killed and/or inactivated by defensins is not understood completely. However, it ... Moreover, human alpha-defensins can enhance or suppress the activation of the classical pathway of complement in vitro by ... suppress anti-inflammatory mediators and regulate complement activation argues that defensins upregulate innate host ...
... groups on each monomeric enzyme molecule that react equally fast with the modifying agent, and n e s s e n t i a l {\ ... but it complements Tsou's approach in useful ways. Suppose that an enzyme has two groups G 1 {\displaystyle \mathrm {G_{1}} } ... is inactivated in a first-order reaction with a different rate constant k 2 {\displaystyle k_{2}} , then the remaining activity ... for which modification of just one essential group by diethyl pyrocarbonate was sufficient to inactivate the enzyme. A little ...
... A71 (EV-A71) is notable as one of the major causative agents for hand, foot and mouth disease (HFMD), and is ... There are two types of vaccines available to prevent polio: inactivated poliovirus vaccine given as an injection in the leg ( ... complement proteins, and proapoptotis proteins have been implicated. There are three serotypes of poliovirus, PV-1, PV-2, and ...
The binding of XNAs initiate complement activation through the classical complement pathway. Complement activation causes a ... Pig organs are anatomically comparable in size, and new infectious agents are less likely since they have been in close contact ... Pig cells have been engineered to inactivate all 62 PERVs in the genome using CRISPR Cas9 genome editing technology, and ... Interruption of the complement cascade The recipient's complement cascade can be inhibited through the use of cobra venom ...

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