The lipopolysaccharide-protein somatic antigens, usually from gram-negative bacteria, important in the serological classification of enteric bacilli. The O-specific chains determine the specificity of the O antigens of a given serotype. O antigens are the immunodominant part of the lipopolysaccharide molecule in the intact bacterial cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Substances that are recognized by the immune system and induce an immune reaction.
Substances elaborated by bacteria that have antigenic activity.
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.
Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.
Substances elaborated by viruses that have antigenic activity.
A species of BORDETELLA with similar morphology to BORDETELLA PERTUSSIS, but growth is more rapid. It is found only in the RESPIRATORY TRACT of humans.
Polysaccharides found in bacteria and in capsules thereof.
A verocytotoxin-producing serogroup belonging to the O subfamily of Escherichia coli which has been shown to cause severe food-borne disease. A strain from this serogroup, serotype H7, which produces SHIGA TOXINS, has been linked to human disease outbreaks resulting from contamination of foods by E. coli O157 from bovine origin.
An enzyme that catalyzes the reversible isomerization of D-mannose-6-phosphate to form D-fructose-6-phosphate, an important step in glycolysis. EC 5.3.1.8.
Process of determining and distinguishing species of bacteria or viruses based on antigens they share.
Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.
Polyomavirus antigens which cause infection and cellular transformation. The large T antigen is necessary for the initiation of viral DNA synthesis, repression of transcription of the early region and is responsible in conjunction with the middle T antigen for the transformation of primary cells. Small T antigen is necessary for the completion of the productive infection cycle.
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.
Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.
Substances of fungal origin that have antigenic activity.
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that utilizes citrate as a sole carbon source. It is pathogenic for humans, causing enteric fevers, gastroenteritis, and bacteremia. Food poisoning is the most common clinical manifestation. Organisms within this genus are separated on the basis of antigenic characteristics, sugar fermentation patterns, and bacteriophage susceptibility.
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)
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.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that is extremely pathogenic and causes severe dysentery. Infection with this organism often leads to ulceration of the intestinal epithelium.
Any part or derivative of a helminth that elicits an immune reaction. The most commonly seen helminth antigens are those of the schistosomes.
Immunoglobulins produced in a response to BACTERIAL ANTIGENS.
Esters formed between the aldehydic carbon of sugars and the terminal phosphate of guanosine diphosphate.
The major group of transplantation antigens in the mouse.
Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.
Tests that are dependent on the clumping of cells, microorganisms, or particles when mixed with specific antiserum. (From Stedman, 26th ed)
A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)
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.
One of the SHIGELLA species that produces bacillary dysentery (DYSENTERY, BACILLARY).
A bacterium which is one of the etiologic agents of bacillary dysentery (DYSENTERY, BACILLARY) and sometimes of infantile gastroenteritis.
A glycoprotein that is secreted into the luminal surface of the epithelia in the gastrointestinal tract. It is found in the feces and pancreaticobiliary secretions and is used to monitor the response to colon cancer treatment.
Sites on an antigen that interact with specific antibodies.
Those proteins recognized by antibodies from serum of animals bearing tumors induced by viruses; these proteins are presumably coded for by the nucleic acids of the same viruses that caused the neoplastic transformation.
Serum that contains antibodies. It is obtained from an animal that has been immunized either by ANTIGEN injection or infection with microorganisms containing the antigen.
Antibodies produced by a single clone of cells.
The functional hereditary units of BACTERIA.
Proteins found in any species of bacterium.
Infections with bacteria of the genus BORDETELLA.
The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.
A subclass of HLA-D antigens that consist of alpha and beta chains. The inheritance of HLA-DR antigens differs from that of the HLA-DQ ANTIGENS and HLA-DP ANTIGENS.
'Deoxy sugars' are monosaccharides or oligosaccharides that contain fewer hydroxyl groups than the corresponding hexose or pentose, with deoxyribose being a well-known example of a deoxy sugar.
Molecules on the surface of T-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (ANTIGENS, CD3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (RECEPTORS, ANTIGEN, T-CELL, ALPHA-BETA) or gamma-delta (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA) chains.
Sensitive tests to measure certain antigens, antibodies, or viruses, using their ability to agglutinate certain erythrocytes. (From Stedman, 26th ed)
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 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.
A subgenus of Salmonella containing several medically important serotypes. The habitat for the majority of strains is warm-blooded animals.
Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.
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 major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.
Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 17 code for the H-2 antigens. The antigens are found on B-lymphocytes, macrophages, epidermal cells, and sperm and are thought to mediate the competence of and cellular cooperation in the immune response. The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen.
A glycoprotein that is a kallikrein-like serine proteinase and an esterase, produced by epithelial cells of both normal and malignant prostate tissue. It is an important marker for the diagnosis of prostate cancer.
IMMUNOGLOBULINS on the surface of B-LYMPHOCYTES. Their MESSENGER RNA contains an EXON with a membrane spanning sequence, producing immunoglobulins in the form of type I transmembrane proteins as opposed to secreted immunoglobulins (ANTIBODIES) which do not contain the membrane spanning segment.
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 enzyme that transfers methyl groups from O(6)-methylguanine, and other methylated moieties of DNA, to a cysteine residue in itself, thus repairing alkylated DNA in a single-step reaction. EC 2.1.1.63.
Enzymes that catalyze the epimerization of chiral centers within carbohydrates or their derivatives. EC 5.1.3.
The processes triggered by interactions of ANTIBODIES with their ANTIGENS.
A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.
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.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Suspensions of attenuated or killed bacteria administered for the prevention or treatment of infectious bacterial disease.
A trisaccharide antigen expressed on glycolipids and many cell-surface glycoproteins. In the blood the antigen is found on the surface of NEUTROPHILS; EOSINOPHILS; and MONOCYTES. In addition, CD15 antigen is a stage-specific embryonic antigen.
The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.
Carbohydrate antigens expressed by malignant tissue. They are useful as tumor markers and are measured in the serum by means of a radioimmunoassay employing monoclonal antibodies.
Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).
A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*02 allele family.
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.
Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. CD8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in MHC (Major Histocompatibility Complex) Class I-restricted interactions.
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.
The clumping together of suspended material resulting from the action of AGGLUTININS.
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.
Sets of cell surface antigens located on BLOOD CELLS. They are usually membrane GLYCOPROTEINS or GLYCOLIPIDS that are antigenically distinguished by their carbohydrate moieties.
Those hepatitis B antigens found on the surface of the Dane particle and on the 20 nm spherical and tubular particles. Several subspecificities of the surface antigen are known. These were formerly called the Australia antigen.
Complex of at least five membrane-bound polypeptides in mature T-lymphocytes that are non-covalently associated with one another and with the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL). The CD3 complex includes the gamma, delta, epsilon, zeta, and eta chains (subunits). When antigen binds to the T-cell receptor, the CD3 complex transduces the activating signals to the cytoplasm of the T-cell. The CD3 gamma and delta chains (subunits) are separate from and not related to the gamma/delta chains of the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA).
Enzymes that catalyze the transfer of glycosyl groups to an acceptor. Most often another carbohydrate molecule acts as an acceptor, but inorganic phosphate can also act as an acceptor, such as in the case of PHOSPHORYLASES. Some of the enzymes in this group also catalyze hydrolysis, which can be regarded as transfer of a glycosyl group from the donor to water. Subclasses include the HEXOSYLTRANSFERASES; PENTOSYLTRANSFERASES; SIALYLTRANSFERASES; and those transferring other glycosyl groups. EC 2.4.
Polymorphic class I human histocompatibility (HLA) surface antigens present on almost all nucleated cells. At least 20 antigens have been identified which are encoded by the A locus of multiple alleles on chromosome 6. They serve as targets for T-cell cytolytic responses and are involved with acceptance or rejection of tissue/organ grafts.
The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.
An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.
Membrane glycoproteins consisting of an alpha subunit and a BETA 2-MICROGLOBULIN beta subunit. In humans, highly polymorphic genes on CHROMOSOME 6 encode the alpha subunits of class I antigens and play an important role in determining the serological specificity of the surface antigen. Class I antigens are found on most nucleated cells and are generally detected by their reactivity with alloantisera. These antigens are recognized during GRAFT REJECTION and restrict cell-mediated lysis of virus-infected cells.
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 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.
DYSENTERY caused by gram-negative rod-shaped enteric bacteria (ENTEROBACTERIACEAE), most often by the genus SHIGELLA. Shigella dysentery, Shigellosis, is classified into subgroups according to syndrome severity and the infectious species. Group A: SHIGELLA DYSENTERIAE (severest); Group B: SHIGELLA FLEXNERI; Group C: SHIGELLA BOYDII; and Group D: SHIGELLA SONNEI (mildest).
Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.
Polysaccharides composed of repeating galactose units. They can consist of branched or unbranched chains in any linkages.
Human immune-response or Class II antigens found mainly, but not exclusively, on B-lymphocytes and produced from genes of the HLA-D locus. They are extremely polymorphic families of glycopeptides, each consisting of two chains, alpha and beta. This group of antigens includes the -DR, -DQ and -DP designations, of which HLA-DR is most studied; some of these glycoproteins are associated with certain diseases, possibly of immune etiology.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Molecules on the surface of B- and T-lymphocytes that recognize and combine with specific antigens.
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.
High-molecular weight glycoproteins uniquely expressed on the surface of LEUKOCYTES and their hemopoietic progenitors. They contain a cytoplasmic protein tyrosine phosphatase activity which plays a role in intracellular signaling from the CELL SURFACE RECEPTORS. The CD45 antigens occur as multiple isoforms that result from alternative mRNA splicing and differential usage of three exons.
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that ferments sugar without gas production. Its organisms are intestinal pathogens of man and other primates and cause bacillary dysentery (DYSENTERY, BACILLARY).
Antigens of the virion of the HEPATITIS B VIRUS or the Dane particle, its surface (HEPATITIS B SURFACE ANTIGENS), core (HEPATITIS B CORE ANTIGENS), and other associated antigens, including the HEPATITIS B E ANTIGENS.
Established cell cultures that have the potential to propagate indefinitely.
A serotype of SALMONELLA ENTERICA which is the etiologic agent of TYPHOID FEVER.
55-kDa antigens found on HELPER-INDUCER T-LYMPHOCYTES and on a variety of other immune cell types. CD4 antigens are members of the immunoglobulin supergene family and are implicated as associative recognition elements in MAJOR HISTOCOMPATIBILITY COMPLEX class II-restricted immune responses. On T-lymphocytes they define the helper/inducer subset. CD4 antigens also serve as INTERLEUKIN-15 receptors and bind to the HIV receptors, binding directly to the HIV ENVELOPE PROTEIN GP120.
A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. aeruginosa is a major agent of nosocomial infection.
Glycoproteins expressed on cortical thymocytes and on some dendritic cells and B-cells. Their structure is similar to that of MHC Class I and their function has been postulated as similar also. CD1 antigens are highly specific markers for human LANGERHANS CELLS.
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.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Nucleoside Diphosphate Sugars (NDPs) are biomolecules consisting of a nucleoside monophosphate sugar molecule, which is formed from the condensation of a nucleotide and a sugar molecule through a pyrophosphate bond.
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.
The etiologic agent of CHOLERA.
Class I human histocompatibility (HLA) surface antigens encoded by more than 30 detectable alleles on locus B of the HLA complex, the most polymorphic of all the HLA specificities. Several of these antigens (e.g., HLA-B27, -B7, -B8) are strongly associated with predisposition to rheumatoid and other autoimmune disorders. Like other class I HLA determinants, they are involved in the cellular immune reactivity of cytolytic T lymphocytes.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria found in soil, water, food, and clinical specimens. It is a prominent opportunistic pathogen for hospitalized patients.
Gram-negative, non-motile, capsulated, gas-producing rods found widely in nature and associated with urinary and respiratory infections in humans.
Antigens expressed primarily on the membranes of living cells during sequential stages of maturation and differentiation. As immunologic markers they have high organ and tissue specificity and are useful as probes in studies of normal cell development as well as neoplastic transformation.
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.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
A species of BORDETELLA that is parasitic and pathogenic. It is found in the respiratory tract of domestic and wild mammalian animals and can be transmitted from animals to man. It is a common cause of bronchopneumonia in lower animals.
A species of gram-negative bacteria and nitrogen innoculant of PHASEOLUS VULGARIS.
An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.
Lipid A is the biologically active component of lipopolysaccharides. It shows strong endotoxic activity and exhibits immunogenic properties.
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 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.
The aggregation of ERYTHROCYTES by AGGLUTININS, including antibodies, lectins, and viral proteins (HEMAGGLUTINATION, VIRAL).
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.
A melanosome-specific protein that plays a role in the expression, stability, trafficking, and processing of GP100 MELANOMA ANTIGEN, which is critical to the formation of Stage II MELANOSOMES. The protein is used as an antigen marker for MELANOMA cells.
Hexoses are simple monosaccharides, specifically six-carbon sugars, which include glucose, fructose, and galactose, and play crucial roles in biological processes such as energy production and storage, and structural components of cells.
Enzymes that catalyze the transfer of hexose groups. EC 2.4.1.-.
Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.
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.
Simultaneous inflammation of the cornea and conjunctiva.
Proteins obtained from ESCHERICHIA COLI.
Antigens associated with specific proteins of the human adult T-cell immunodeficiency virus (HIV); also called HTLV-III-associated and lymphadenopathy-associated virus (LAV) antigens.
A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CTLA-4 ANTIGEN with high specificity and to CD28 ANTIGEN with low specificity. The interaction of CD80 with CD28 ANTIGEN provides a costimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.
Small synthetic peptides that mimic surface antigens of pathogens and are immunogenic, or vaccines manufactured with the aid of recombinant DNA techniques. The latter vaccines may also be whole viruses whose nucleic acids have been modified.
Enzymes that catalyze the breakage of a carbon-oxygen bond leading to unsaturated products via the removal of water. EC 4.2.1.
Nuclear antigens encoded by VIRAL GENES found in HUMAN HERPESVIRUS 4. At least six nuclear antigens have been identified.
Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.
Differentiation antigens expressed on B-lymphocytes and B-cell precursors. They are involved in regulation of B-cell proliferation.
Heptoses are rare monosaccharides (simple sugars) containing seven carbon atoms, with a general formula of C7H14O7, which can exist in various structural forms such as D-glycero-D-manno-heptose and D-glycero-D-gulo-heptose.
Antigens stimulating the formation of, or combining with heterophile antibodies. They are cross-reacting antigens found in phylogenetically unrelated species.
Gram-negative rods isolated from human urine and feces.
A species of gram-negative, facultatively anaerobic coccobacillus-shaped bacteria that has been isolated from pneumonic lesions and blood. It produces pneumonia with accompanying fibrinous pleuritis in swine.
An acute diarrheal disease endemic in India and Southeast Asia whose causative agent is VIBRIO CHOLERAE. This condition can lead to severe dehydration in a matter of hours unless quickly treated.
The hepatitis B antigen within the core of the Dane particle, the infectious hepatitis virion.
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.
The sum of the weight of all the atoms in a molecule.
An enzyme that catalyzes the formation of UDPglucose from UTP plus glucose 1-phosphate. EC 2.7.7.9.
A necessary enzyme in the metabolism of galactose. It reversibly catalyzes the conversion of UDPglucose to UDPgalactose. NAD+ is an essential component for enzymatic activity. EC 5.1.3.2.
A genus of filamentous bacteriophages of the family INOVIRIDAE. Organisms of this genus infect enterobacteria, PSEUDOMONAS; VIBRIO; and XANTHOMONAS.
An encapsulated lymphatic organ through which venous blood filters.
A member of the tumor necrosis factor receptor superfamily with specificity for CD40 LIGAND. It is found on mature B-LYMPHOCYTES and some EPITHELIAL CELLS, lymphoid DENDRITIC CELLS. Evidence suggests that CD40-dependent activation of B-cells is important for generation of memory B-cells within the germinal centers. Mutations of the gene for CD40 antigen result in HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 3. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.
Endogenous tissue constituents that have the ability to interact with AUTOANTIBODIES and cause an immune response.
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).
A genus of gram-negative, aerobic bacteria whose cells are minute coccobacilli. It consists of both parasitic and pathogenic species.
A serotype of Salmonella enterica which is an etiologic agent of gastroenteritis in man and other animals.
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.
A group of differentiation surface antigens, among the first to be discovered on thymocytes and T-lymphocytes. Originally identified in the mouse, they are also found in other species including humans, and are expressed on brain neurons and other cells.
A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in the intestines of humans and a wide variety of animals, as well as in manure, soil, and polluted waters. Its species are pathogenic, causing urinary tract infections and are also considered secondary invaders, causing septic lesions at other sites of the body.
Proteins isolated from the outer membrane of Gram-negative bacteria.
A glycolipid, cross-species antigen that induces production of antisheep hemolysin. It is present on the tissue cells of many species but absent in humans. It is found in many infectious agents.
Infections with bacteria of the species ESCHERICHIA COLI.
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.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
A sex-specific cell surface antigen produced by the sex-determining gene of the Y chromosome in mammals. It causes syngeneic grafts from males to females to be rejected and interacts with somatic elements of the embryologic undifferentiated gonad to produce testicular organogenesis.
The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.
A species of the genus BRUCELLA whose natural hosts are cattle and other bovidae. Abortion and placentitis are frequently produced in the pregnant animal. Other mammals, including humans, may be infected.
A genus of gram-negative, aerobic, rod-shaped bacteria. Organisms in this genus had originally been classified as members of the PSEUDOMONAS genus but overwhelming biochemical and chemical findings indicated the need to separate them from other Pseudomonas species, and hence, this new genus was created.
A heterogeneous group of immunocompetent cells that mediate the cellular immune response by processing and presenting antigens to the T-cells. Traditional antigen-presenting cells include MACROPHAGES; DENDRITIC CELLS; LANGERHANS CELLS; and B-LYMPHOCYTES. FOLLICULAR DENDRITIC CELLS are not traditional antigen-presenting cells, but because they hold antigen on their cell surface in the form of IMMUNE COMPLEXES for B-cell recognition they are considered so by some authors.
Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as SKIN and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process ANTIGENS, and present them to T-CELLS, thereby stimulating CELL-MEDIATED IMMUNITY. They are different from the non-hematopoietic FOLLICULAR DENDRITIC CELLS, which have a similar morphology and immune system function, but with respect to humoral immunity (ANTIBODY PRODUCTION).
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 group of the D-related HLA antigens found to differ from the DR antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases.
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.
A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CD28 ANTIGEN with high specificity and to CTLA-4 ANTIGEN with low specificity. The interaction of CD86 with CD28 ANTIGEN provides a stimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.
An albumin obtained from the white of eggs. It is a member of the serpin superfamily.
Proteins prepared by recombinant DNA technology.
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 species of POLYOMAVIRUS originally isolated from Rhesus monkey kidney tissue. It produces malignancy in human and newborn hamster kidney cell cultures.
Immunized T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (MLC), in vivo during a graft-versus-host (GVH) reaction, or after immunization with an allograft, tumor cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (CML). These CD8-positive cells are distinct from NATURAL KILLER CELLS and NATURAL KILLER T-CELLS. There are two effector phenotypes: TC1 and TC2.
Viruses whose host is Salmonella. A frequently encountered Salmonella phage is BACTERIOPHAGE P22.
Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.
Elements of limited time intervals, contributing to particular results or situations.
A class of enzymes that transfers substituted phosphate groups. EC 2.7.8.
T-cell receptors composed of CD3-associated alpha and beta polypeptide chains and expressed primarily in CD4+ or CD8+ T-cells. Unlike immunoglobulins, the alpha-beta T-cell receptors recognize antigens only when presented in association with major histocompatibility (MHC) molecules.
Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.
White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
Immunoglobulins produced in response to VIRAL ANTIGENS.
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.
An inhibitory T CELL receptor that is closely related to CD28 ANTIGEN. It has specificity for CD80 ANTIGEN and CD86 ANTIGEN and acts as a negative regulator of peripheral T cell function. CTLA-4 antigen is believed to play role in inducing PERIPHERAL TOLERANCE.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
Phosphate esters of THYMIDINE in N-glycosidic linkage with ribose or deoxyribose, as occurs in nucleic acids. (From Dorland, 28th ed, p1154)
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).
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.
A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)
Enzymes that catalyze the joining of two molecules by the formation of a carbon-oxygen bond. EC 6.1.
Fucose is a deoxyhexose sugar, specifically a L-configuration 6-deoxygalactose, often found as a component of complex carbohydrates called glycans in various glycoproteins and glycolipids within the human body.
The major human blood type system which depends on the presence or absence of two antigens A and B. Type O occurs when neither A nor B is present and AB when both are present. A and B are genetic factors that determine the presence of enzymes for the synthesis of certain glycoproteins mainly in the red cell membrane.
A component of the B-cell antigen receptor that is involved in B-cell antigen receptor heavy chain transport to the PLASMA MEMBRANE. It is expressed almost exclusively in B-LYMPHOCYTES and serves as a useful marker for B-cell NEOPLASMS.
A mixture of polymyxins B1 and B2, obtained from Bacillus polymyxa strains. They are basic polypeptides of about eight amino acids and have cationic detergent action on cell membranes. Polymyxin B is used for infections with gram-negative organisms, but may be neurotoxic and nephrotoxic.
Immunoglobulins produced in a response to PROTOZOAN ANTIGENS.
The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).
Sialylated Lewis blood group carbohydrate antigen found in many adenocarcinomas of the digestive tract, especially pancreatic tumors.

P fimbriae and other adhesins enhance intestinal persistence of Escherichia coli in early infancy. (1/1070)

Resident and transient Escherichia coli strains were identified in the rectal flora of 22 Pakistani infants followed from birth to 6 months of age. All strains were tested for O-antigen expression, adhesin specificity (P fimbriae, other mannose-resistant adhesins or type 1 fimbriae) and adherence to the colonic cell line HT-29. Resident strains displayed higher mannose-resistant adherence to HT-29 cells, and expressed P fimbriae (P = 0.0036) as well as other mannose-resistant adhesins (P = 0.012) more often than transient strains. In strains acquired during the first month of life, P fimbriae were 12 times more frequent in resident than in transient strains (P = 0.0006). The O-antigen distribution did not differ between resident and transient strains, and none of the resident P-fimbriated strains belonged to previously recognized uropathogenic clones. The results suggest that adhesins mediating adherence to intestinal epithelial cells, especially P fimbriae, enhance the persistence of E. coli in the large intestine of infants.  (+info)

Genetic analysis of the Serratia marcescens N28b O4 antigen gene cluster. (2/1070)

The Serratia marcescens N28b wbbL gene has been shown to complement the rfb-50 mutation of Escherichia coli K-12 derivatives, and a wbbL mutant has been shown to be impaired in O4-antigen biosynthesis (X. Rubires, F. Saigi, N. Pique, N. Climent, S. Merino, S. Alberti, J. M. Tomas, and M. Regue, J. Bacteriol. 179:7581-7586, 1997). We analyzed a recombinant cosmid containing the wbbL gene by subcloning and determination of O-antigen production phenotype in E. coli DH5alpha by sodium dodecyl sulfate-polyacrylamide electrophoresis and Western blot experiments with S. marcescens O4 antiserum. The results obtained showed that a recombinant plasmid (pSUB6) containing about 10 kb of DNA insert was enough to induce O4-antigen biosynthesis. The same results were obtained when an E. coli K-12 strain with a deletion of the wb cluster was used, suggesting that the O4 wb cluster is located in pSUB6. No O4 antigen was produced when plasmid pSUB6 was introduced in a wecA mutant E. coli strain, suggesting that O4-antigen production is wecA dependent. Nucleotide sequence determination of the whole insert in plasmid pSUB6 showed seven open reading frames (ORFs). On the basis of protein similarity analysis of the ORF-encoded proteins and analysis of the S. marcescens N28b wbbA insertion mutant and wzm-wzt deletion mutant, we suggest that the O4 wb cluster codes for two dTDP-rhamnose biosynthetic enzymes (RmlDC), a rhamnosyltransferase (WbbL), a two-component ATP-binding-cassette-type export system (Wzm Wzt), and a putative glycosyltransferase (WbbA). A sequence showing DNA homology to insertion element IS4 was found downstream from the last gene in the cluster (wbbA), suggesting that an IS4-like element could have been involved in the acquisition of the O4 wb cluster.  (+info)

Structural analysis of a novel putative capsular polysaccharide from Pseudomonas (Burkholderia) caryophylli strain 2151. (3/1070)

A novel putative capsular polysaccharide consisting of D-Glcp and D-Fruf in the molar ratio of 1:1 was isolated as minor constituent from the lipopolysaccharide (LPS) fraction of Pseudomonas (Burkholderia) caryophylli. Its structure was determined, using mainly one- and two-dimensional NMR spectroscopy, as: -->6)-alpha-D-Glcp-(1-->1)-beta-D-Fruf-(2-->.  (+info)

Structural and serological studies on the O-antigen of Proteus mirabilis O14, a new polysaccharide containing 2-[(R)-1-carboxyethylamino]ethyl phosphate. (4/1070)

An O-specific polysaccharide was obtained by mild acid degradation of Proteus mirabilis O14 lipopolysaccharide (LPS) and found to contain D-galactose, 2-acetamido-2-deoxy-D-glalactose, phosphate, N-(2-hydroxyethyl)-D-alanine (D-AlaEtn), and O-acetyl groups. Studies of the initial and O-deacetylated polysaccharides using one- and two-dimensional 1H- and 13C-NMR spectroscopy, including COSY, TOCSY, NOESY, H-detected 1H,13C heteronuclear multiple-quantum coherence, and heteronuclear multiple-bond correlation experiments, demonstrated the following structure of the repeating unit: [equation: see text] This is the second bacterial polysaccharide reported to contain alpha-D-Galp6PAlaEtn, whereas the first one was the O-antigen of P. mirabilis EU313 taken erroneously as strain PrK 6/57 from the O3 serogroup [Vinogradov, E. V., Kaca, W., Shashkov, A.S., Krajewska-Pietrasik, D., Rozalski, A., Knirel, Y.A. & Kochetkov, N.K. (1990) Eur. J. Biochem., 188, 645-651]. Anti-(P. mirabilis O14) serum cross-reacted with LPS of P. mirabilis EU313 and vice versa in passive hemolysis and ELISA. Absorption of both O-antisera with the heterologous LPS decreased markedly but did not abolish the reaction with the homologous LPS. These and chemical data indicated that both strains have similar but not identical O-antigens. Therefore, we propose that P. mirabilis EU313 should belong to a new subgroup of the O14 serogroup.  (+info)

Structure of the O-specific polysaccharide of a serologically separate strain Proteus penneri 2 from a new proposed serogroup O66. (5/1070)

O-specific polysaccharide chain of Proteus penneri strain 2 lipopolysaccharide was studied by full and partial acid hydrolysis, Smith degradation, methylation analysis, and NMR spectroscopy, including two-dimensional rotating-frame NOE spectroscopy (ROESY) and 1H,13C heteronuclear multiple-quantum coherence (HMQC) experiments. Together with D-glucose and 2-acetamido-2-deoxy-D-glucose, the polysaccharide was found to contain two rarely occurring sugars, 6-deoxy-L-talose (L-6dTal) and 2,3-diacetamido-2,3,6-trideoxy-L-mannose (L-RhaNAc3NAc), and the following structure of a non-stoichiometrically O-acetylated tetrasaccharide repeating unit was established: [equation: see text] The O-specific polysaccharide studied has a unique composition and structure and, accordingly, P. penneri 2 is serologically separate among Proteus strains. Therefore, we propose for P. penneri 2 a new Proteus O-serogroup O66 where this strain is at present the single representative.  (+info)

Protein conjugates of synthetic saccharides elicit higher levels of serum IgG lipopolysaccharide antibodies in mice than do those of the O-specific polysaccharide from Shigella dysenteriae type 1. (6/1070)

Our development of vaccines to prevent shigellosis is based on the hypothesis that a critical (protective) level of serum IgG to the O-specific polysaccharide (O-SP) domain of Shigella lipopolysaccharide (LPS) confers immunity. The O-SP is a hapten and must be conjugated to a protein to induce serum antibodies. The O-SP of Shigella dysenteriae type 1 (approximately 27 tetrasaccharide repeat units), prepared by acid hydrolysis of the LPS, was bound to human serum albumin (HSA) by multiple point attachment (O-SP-HSA): The molar ratio of HSA to O-SP was 1.0. Synthetic saccharides, composed of one or multiples of the O-SP tetrasaccharide, equipped with a spacer at their reducing end, were bound to HSA by a single point attachment: The average molar ratios of the saccharides to HSA ranged from 4 to 24. Serum IgG anti-LPS, elicited in mice by O-SP-HSA or synthetic tetra-, octa-, dodeca-, and hexadecasaccharide fragments, was measured by ELISA. Outbred 6-week-old female mice were injected s.c. three times at biweekly intervals with 2.5 micrograms of saccharide as a conjugate and were bled 7 days after the second and third injections. Excepting the tetramer, conjugates of the octamer, dodecamer and hexadecamer elicited IgG LPS antibodies after the second injection, a statistically significant rise (booster) after the third injection, and higher levels than those vaccinated with O-SP-HSA (P = 0.0001). The highest geometric mean levels of IgG anti-LPS were elicited by the hexadecamer with 9 chains or 9 moles of saccharide/HSA (15.5 ELISA units) followed by the octamer with 20 chains (11.1 ELISA units) and the dodecamer with 10 chains (9.52 ELISA units). Clinical evaluation of these synthetic saccharides bound to a medically useful carrier is planned.  (+info)

Identification of Acinetobacter baumannii strains with monoclonal antibodies against the O antigens of their lipopolysaccharides. (7/1070)

Despite the emergence of Acinetobacter baumannii strains as nosocomial pathogens, simple methods for their phenotypic identification are still unavailable. Murine monoclonal antibodies specific for the O-polysaccharide moiety of the lipopolysaccharide (LPS) of two A. baumannii strains were obtained after immunization with heat-killed bacteria. The monoclonal antibodies were characterized by enzyme immunoassay and by Western and dot blot analyses and were investigated for their potential use for the identification of A. baumannii strains. The antibodies reacted with 46 of the 80 A. baumannii clinical isolates that were investigated, and reactivity was observed with 11 of 14 strains which were isolated during outbreaks in different northwestern European cities; no reactivity was observed with Acinetobacter strains of other genomic species, including the closely related genomic species 1 (Acinetobacter calcoaceticus), 3, and 13 sensu Tjernberg and Ursing, or with other gram-negative bacterial strains. The results show that O-antigen-specific monoclonal antibodies such as the ones described are convenient reagents which can be used to identify Acinetobacter strains in clinical and research laboratories.  (+info)

Safety and immunogenicity of Shigella sonnei and Shigella flexneri 2a O-specific polysaccharide conjugates in children. (8/1070)

O-specific polysaccharide conjugates of shigellae were safe and immunogenic in young adults, and a Shigella sonnei conjugate conferred protection [1-3]. Shigellosis is primarily a disease of children; therefore, the safety and immunogenicity of S. sonnei and Shigella flexneri 2a conjugates were studied in 4- to 7-year-old children. Local and systemic reactions were minimal. The first injection of both conjugates elicited significant rises in geometric mean levels of serum IgG only to the homologous lipopolysaccharide (LPS) (S. sonnei, 0.32-8.25 ELISA units [EU]; S. flexneri 2a, 1.15-20.5 EU; P<.0001). Revaccination at 6 weeks induced a booster response to S. flexneri 2a LPS (20.5-30.5 EU, P=.003). Six months later, the geometric mean levels of IgG anti-LPS for both groups were higher than the prevaccination levels (P<.0001). Similar, but lesser, rises were observed for IgM and IgA anti-LPS. The investigational Shigella conjugates were safe and immunogenic in children and merit evaluation of their efficacy.  (+info)

"O antigens" are a type of antigen found on the lipopolysaccharide (LPS) component of the outer membrane of Gram-negative bacteria. The "O" in O antigens stands for "outer" membrane. These antigens are composed of complex carbohydrates and can vary between different strains of the same species of bacteria, which is why they are also referred to as the bacterial "O" somatic antigens.

The O antigens play a crucial role in the virulence and pathogenesis of many Gram-negative bacteria, as they help the bacteria evade the host's immune system by changing the structure of the O antigen, making it difficult for the host to mount an effective immune response against the bacterial infection.

The identification and classification of O antigens are important in epidemiology, clinical microbiology, and vaccine development, as they can be used to differentiate between different strains of bacteria and to develop vaccines that provide protection against specific bacterial infections.

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.

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.

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.

Neoplasm antigens, also known as tumor antigens, are substances that are produced by cancer cells (neoplasms) and can stimulate an immune response. These antigens can be proteins, carbohydrates, or other molecules that are either unique to the cancer cells or are overexpressed or mutated versions of normal cellular proteins.

Neoplasm antigens can be classified into two main categories: tumor-specific antigens (TSAs) and tumor-associated antigens (TAAs). TSAs are unique to cancer cells and are not expressed by normal cells, while TAAs are present at low levels in normal cells but are overexpressed or altered in cancer cells.

TSAs can be further divided into viral antigens and mutated antigens. Viral antigens are produced when cancer is caused by a virus, such as human papillomavirus (HPV) in cervical cancer. Mutated antigens are the result of genetic mutations that occur during cancer development and are unique to each patient's tumor.

Neoplasm antigens play an important role in the immune response against cancer. They can be recognized by the immune system, leading to the activation of immune cells such as T cells and natural killer (NK) cells, which can then attack and destroy cancer cells. However, cancer cells often develop mechanisms to evade the immune response, allowing them to continue growing and spreading.

Understanding neoplasm antigens is important for the development of cancer immunotherapies, which aim to enhance the body's natural immune response against cancer. These therapies include checkpoint inhibitors, which block proteins that inhibit T cell activation, and therapeutic vaccines, which stimulate an immune response against specific tumor antigens.

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.

'Bordetella parapertussis' is a gram-negative, coccobacillus bacterium that can cause a respiratory infection in humans. It is one of the several species in the genus Bordetella and is closely related to Bordetella pertussis, which causes whooping cough (pertussis).

Bordetella parapertussis infection often results in symptoms similar to those of pertussis but are usually less severe. The illness is sometimes referred to as "mild whooping cough" or "whooping cough-like illness."

The bacterium primarily infects the respiratory tract, attaching to the ciliated epithelial cells lining the airways. This leads to inflammation and damage of the respiratory mucosa, causing a persistent cough, which may be accompanied by paroxysms (intense fits of coughing), inspiratory whoop, and post-tussive vomiting.

Transmission occurs through respiratory droplets when an infected person sneezes or coughs near someone else. The incubation period for Bordetella parapertussis infection is typically 7 to 10 days but can range from 5 to 21 days.

Prevention and control measures include vaccination, good hygiene practices (such as covering the mouth and nose when coughing or sneezing), and early detection and treatment of infected individuals. Antibiotics such as macrolides (e.g., azithromycin, erythromycin) are often used to treat Bordetella parapertussis infections, helping to reduce the duration of symptoms and limit transmission to others.

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.

Escherichia coli (E. coli) O157 is a serotype of the bacterium E. coli that is associated with foodborne illness. This strain is pathogenic and produces Shiga toxins, which can cause severe damage to the lining of the small intestine and potentially lead to hemorrhagic diarrhea and kidney failure. E. coli O157 is often transmitted through contaminated food, particularly undercooked ground beef, as well as raw or unpasteurized dairy products, fruits, and vegetables. It can also be spread through contact with infected individuals or animals, especially in settings like farms, petting zoos, and swimming pools. Proper food handling, cooking, and hygiene practices are crucial to preventing E. coli O157 infections.

Mannose-6-Phosphate Isomerase (MPI) is an enzyme that catalyzes the interconversion between mannose-6-phosphate and fructose-6-phosphate, which are both key metabolites in the glycolysis and gluconeogenesis pathways. This enzyme plays a crucial role in maintaining the balance between these two metabolic pathways, allowing cells to either break down or synthesize glucose depending on their energy needs.

The gene that encodes for MPI is called MPI1 and is located on chromosome 4 in humans. Defects in this gene can lead to a rare genetic disorder known as Mannose-6-Phosphate Isomerase Deficiency or Congenital Disorder of Glycosylation Type IIm, which is characterized by developmental delay, intellectual disability, seizures, and various other neurological symptoms.

Serotyping is a laboratory technique used to classify microorganisms, such as bacteria and viruses, based on the specific antigens or proteins present on their surface. It involves treating the microorganism with different types of antibodies and observing which ones bind to its surface. Each distinct set of antigens corresponds to a specific serotype, allowing for precise identification and characterization of the microorganism. This technique is particularly useful in epidemiology, vaccine development, and infection control.

Antigens are substances (usually proteins) found on the surface of cells, or viruses, that can be recognized by the immune system and stimulate an immune response. In the context of protozoa, antigens refer to the specific proteins or other molecules found on the surface of these single-celled organisms that can trigger an immune response in a host organism.

Protozoa are a group of microscopic eukaryotic organisms that include a diverse range of species, some of which can cause diseases in humans and animals. When a protozoan infects a host, the host's immune system recognizes the protozoan antigens as foreign and mounts an immune response to eliminate the infection. This response involves the activation of various types of immune cells, such as T-cells and B-cells, which recognize and target the protozoan antigens.

Understanding the nature of protozoan antigens is important for developing vaccines and other immunotherapies to prevent or treat protozoan infections. For example, researchers have identified specific antigens on the surface of the malaria parasite that are recognized by the human immune system and have used this information to develop vaccine candidates. However, many protozoan infections remain difficult to prevent or treat, and further research is needed to identify new targets for vaccines and therapies.

Polyomavirus transforming antigens refer to specific proteins expressed by polyomaviruses that can induce cellular transformation and lead to the development of cancer. These antigens are called large T antigen (T-Ag) and small t antigen (t-Ag). They manipulate key cellular processes, such as cell cycle regulation and DNA damage response, leading to uncontrolled cell growth and malignant transformation.

The large T antigen is a multifunctional protein that plays a crucial role in viral replication and transformation. It has several domains with different functions:

1. Origin binding domain (OBD): Binds to the viral origin of replication, initiating DNA synthesis.
2. Helicase domain: Unwinds double-stranded DNA during replication.
3. DNA binding domain: Binds to specific DNA sequences and acts as a transcriptional regulator.
4. Protein phosphatase 1 (PP1) binding domain: Recruits PP1 to promote viral DNA replication and inhibit host cell defense mechanisms.
5. p53-binding domain: Binds and inactivates the tumor suppressor protein p53, promoting cell cycle progression and preventing apoptosis.
6. Rb-binding domain: Binds to and inactivates the retinoblastoma protein (pRb), leading to deregulation of the cell cycle and uncontrolled cell growth.

The small t antigen shares a common N-terminal region with large T antigen but lacks some functional domains, such as the OBD and helicase domain. Small t antigen can also bind to and inactivate PP1 and pRb, contributing to transformation. However, its primary role is to stabilize large T antigen by preventing its proteasomal degradation.

Polyomavirus transforming antigens are associated with various human cancers, such as Merkel cell carcinoma (caused by Merkel cell polyomavirus) and some forms of brain tumors, sarcomas, and lymphomas (associated with simian virus 40).

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.

HLA (Human Leukocyte Antigen) antigens are a group of proteins found on the surface of cells in our body. They play a crucial role in the immune system's ability to differentiate between "self" and "non-self." HLA antigens are encoded by a group of genes located on chromosome 6, known as the major histocompatibility complex (MHC).

There are three types of HLA antigens: HLA class I, HLA class II, and HLA class III. HLA class I antigens are found on the surface of almost all cells in the body and help the immune system recognize and destroy virus-infected or cancerous cells. They consist of three components: HLA-A, HLA-B, and HLA-C.

HLA class II antigens are primarily found on the surface of immune cells, such as macrophages, B cells, and dendritic cells. They assist in the presentation of foreign particles (like bacteria and viruses) to CD4+ T cells, which then activate other parts of the immune system. HLA class II antigens include HLA-DP, HLA-DQ, and HLA-DR.

HLA class III antigens consist of various molecules involved in immune responses, such as cytokines and complement components. They are not directly related to antigen presentation.

The genetic diversity of HLA antigens is extensive, with thousands of variations or alleles. This diversity allows for a better ability to recognize and respond to a wide range of pathogens. However, this variation can also lead to compatibility issues in organ transplantation, as the recipient's immune system may recognize the donor's HLA antigens as foreign and attack the transplanted organ.

Fungal antigens are substances found on or produced by fungi that can stimulate an immune response in a host organism. They can be proteins, polysaccharides, or other molecules that are recognized as foreign by the host's immune system. Fungal antigens can be used in diagnostic tests to identify fungal infections, and they can also be targets of immune responses during fungal infections. In some cases, fungal antigens may contribute to the pathogenesis of fungal diseases by inducing inflammatory or allergic reactions. Examples of fungal antigens include the cell wall components of Candida albicans and the extracellular polysaccharide galactomannan produced by Aspergillus fumigatus.

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).

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.

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.

"Shigella dysenteriae" is a specific species of bacteria that can cause severe forms of dysentery, a type of diarrheal disease. The infection caused by this bacterium is known as shigellosis. Shigella dysenteriae is highly infectious and can be transmitted through direct contact with an infected person or through contaminated food or water.

The bacteria produce toxins that can cause inflammation and damage to the lining of the intestine, leading to symptoms such as diarrhea (often containing blood and mucus), abdominal cramps, fever, and tenesmus (the urgent need to have a bowel movement). In severe cases, shigellosis can lead to complications such as dehydration, seizures, and hemolytic-uremic syndrome (HUS), a serious condition that can cause kidney failure.

Shigella dysenteriae is a public health concern, particularly in areas with poor sanitation and hygiene practices. Prevention measures include good hand hygiene, safe food handling practices, and access to clean water. Treatment typically involves antibiotics, fluids, and electrolyte replacement to manage symptoms and prevent complications.

Helminth antigens refer to the proteins or other molecules found on the surface or within helminth parasites that can stimulate an immune response in a host organism. Helminths are large, multicellular parasitic worms that can infect various tissues and organs in humans and animals, causing diseases such as schistosomiasis, lymphatic filariasis, and soil-transmitted helminthiases.

Helminth antigens can be recognized by the host's immune system as foreign invaders, leading to the activation of various immune cells and the production of antibodies. However, many helminths have evolved mechanisms to evade or suppress the host's immune response, allowing them to establish long-term infections.

Studying helminth antigens is important for understanding the immunology of helminth infections and developing new strategies for diagnosis, treatment, and prevention. Some researchers have also explored the potential therapeutic use of helminth antigens or whole helminths as a way to modulate the immune system and treat autoimmune diseases or allergies. However, more research is needed to determine the safety and efficacy of these approaches.

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.

Guanosine diphosphate sugars (GDP-sugars) are nucleotide sugars that play a crucial role in the biosynthesis of complex carbohydrates, such as glycoproteins and proteoglycans. Nucleotide sugars are formed by the attachment of a sugar molecule to a nucleoside diphosphate, in this case, guanosine diphosphate (GDP).

GDP-sugars serve as activated donor substrates for glycosyltransferases, enzymes that catalyze the transfer of sugar moieties onto various acceptor molecules, including proteins and lipids. The GDP-sugar synthesis pathway involves several enzymatic steps, starting with the conversion of nucleoside triphosphate (NTP) to nucleoside diphosphate (NDP), followed by the attachment of a sugar moiety from a donor molecule, such as UDP-glucose or TDP-rhamnose.

Examples of GDP-sugars include:

1. GDP-mannose: A nucleotide sugar that serves as a donor substrate for the addition of mannose residues to glycoproteins and proteoglycans.
2. GDP-fucose: A nucleotide sugar that is involved in the biosynthesis of fucosylated glycoconjugates, which have important functions in cell recognition, signaling, and development.
3. GDP-rhamnose: A nucleotide sugar that plays a role in the synthesis of rhamnosylated glycoconjugates, found in bacterial cell walls and some plant polysaccharides.
4. GDP-glucose: A nucleotide sugar that is used as a donor substrate for the addition of glucose residues to various acceptors, including proteins and lipids.

Dysregulation of GDP-sugar metabolism has been implicated in several diseases, such as cancer, neurodegenerative disorders, and bacterial and viral infections. Therefore, understanding the synthesis, regulation, and function of GDP-sugars is crucial for developing novel therapeutic strategies to target these conditions.

H-2 antigens are a group of cell surface proteins found in mice that play a critical role in the immune system. They are similar to the human leukocyte antigen (HLA) complex in humans and are involved in the presentation of peptide antigens to T cells, which is a crucial step in the adaptive immune response.

The H-2 antigens are encoded by a cluster of genes located on chromosome 17 in mice. They are highly polymorphic, meaning that there are many different variations of these proteins circulating in the population. This genetic diversity allows for a wide range of potential peptide antigens to be presented to T cells, thereby enhancing the ability of the immune system to recognize and respond to a variety of pathogens.

The H-2 antigens are divided into two classes based on their function and structure. Class I H-2 antigens are found on almost all nucleated cells and consist of a heavy chain, a light chain, and a peptide fragment. They present endogenous peptides, such as those derived from viruses that infect the cell, to CD8+ T cells.

Class II H-2 antigens, on the other hand, are found primarily on professional antigen-presenting cells, such as dendritic cells and macrophages. They consist of an alpha chain and a beta chain and present exogenous peptides, such as those derived from bacteria that have been engulfed by the cell, to CD4+ T cells.

Overall, H-2 antigens are essential components of the mouse immune system, allowing for the recognition and elimination of pathogens and infected cells.

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.

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.

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.

'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.

Shigella boydii is a subgroup or species of the genus Shigella, which are gram-negative, rod-shaped bacteria that can cause gastrointestinal illness in humans. The illness caused by S. boydii, as well as other Shigella species, is known as shigellosis or bacillary dysentery.

S. boydii is further divided into several subgroups or serotypes based on their surface antigens. This bacterium is primarily transmitted through the fecal-oral route, often via contaminated food or water, and can cause symptoms such as diarrhea (often with blood and mucus), abdominal cramps, fever, and vomiting.

Shigellosis caused by S. boydii tends to be less common compared to other Shigella species like S. dysenteriae, S. flexneri, and S. sonnei. However, the severity of the illness can vary widely, with some individuals experiencing mild symptoms while others may develop severe, life-threatening complications, particularly in young children, the elderly, and those with weakened immune systems.

Shigella flexneri is a species of Gram-negative, facultatively anaerobic, rod-shaped bacteria that belongs to the family Enterobacteriaceae. It is one of the four species of the genus Shigella, which are the causative agents of shigellosis, also known as bacillary dysentery.

Shigella flexneri is responsible for causing a significant proportion of shigellosis cases worldwide, particularly in developing countries with poor sanitation and hygiene practices. The bacteria can be transmitted through the fecal-oral route, often via contaminated food or water, and can cause severe gastrointestinal symptoms such as diarrhea, abdominal cramps, fever, and tenesmus (the urgent need to defecate).

The infection can lead to inflammation of the mucous membrane lining the intestines, resulting in the destruction of the epithelial cells and the formation of ulcers. In severe cases, Shigella flexneri can invade the bloodstream and cause systemic infections, which can be life-threatening for young children, the elderly, and immunocompromised individuals.

The diagnosis of Shigella flexneri infection typically involves the detection of the bacteria in stool samples using culture methods or molecular techniques such as PCR. Treatment usually involves antibiotics, although resistance to multiple drugs has been reported in some strains. Preventive measures include good hygiene practices, safe food handling, and access to clean water.

Carcinoembryonic antigen (CEA) is a protein that is normally produced in small amounts during fetal development. In adults, low levels of CEA can be found in the blood, but elevated levels are typically associated with various types of cancer, particularly colon, rectal, and breast cancer.

Measurement of CEA levels in the blood is sometimes used as a tumor marker to monitor response to treatment, detect recurrence, or screen for secondary cancers in patients with a history of certain types of cancer. However, it's important to note that CEA is not a specific or sensitive indicator of cancer and can be elevated in various benign conditions such as inflammation, smoking, and some gastrointestinal diseases. Therefore, the test should be interpreted in conjunction with other clinical and diagnostic findings.

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.

Antigens are substances that trigger an immune response in the body, leading to the production of antibodies. Antigens can be proteins, polysaccharides, or other molecules found on the surface of cells or viruses.

Viral antigens are antigens that are present on the surface of viruses. When a virus infects a cell, it may display viral antigens on the surface of the infected cell. This can alert the immune system to the presence of the virus and trigger an immune response.

Tumor antigens are antigens that are present on the surface of cancer cells. These antigens may be unique to the cancer cells, or they may be similar to antigens found on normal cells. Tumor antigens can be recognized by the immune system as foreign, leading to an immune response against the cancer cells.

It is important to note that not all viral infections lead to cancer, and not all tumors are caused by viruses. However, some viruses have been linked to an increased risk of certain types of cancer. For example, human papillomavirus (HPV) has been associated with an increased risk of cervical, anal, and oral cancers. In these cases, the virus may introduce viral antigens into the cells it infects, leading to an altered presentation of tumor antigens on the surface of the infected cells. This can potentially trigger an immune response against both the viral antigens and the tumor antigens, which may help to prevent or slow the growth of the cancer.

'Immune sera' refers to the serum fraction of blood that contains antibodies produced in response to an antigenic stimulus, such as a vaccine or an infection. These antibodies are proteins known as immunoglobulins, which are secreted by B cells (a type of white blood cell) and can recognize and bind to specific antigens. Immune sera can be collected from an immunized individual and used as a source of passive immunity to protect against infection or disease. It is often used in research and diagnostic settings to identify or measure the presence of specific antigens or antibodies.

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 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.

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.

Bordetella infections are caused by bacteria called Bordetella pertussis or Bordetella parapertussis, which result in a highly contagious respiratory infection known as whooping cough or pertussis. These bacteria primarily infect the respiratory cilia (tiny hair-like structures lining the upper airways) and produce toxins that cause inflammation and damage to the respiratory tract.

The infection typically starts with cold-like symptoms, including a runny nose, sneezing, and a mild cough. After about one to two weeks, the cough becomes more severe, leading to episodes of intense, uncontrollable coughing fits that can last for several minutes. These fits often end with a high-pitched "whoop" sound as the person gasps for air. Vomiting may occur following the coughing spells.

Bordetella infections can be particularly severe and even life-threatening in infants, young children, and people with weakened immune systems. Complications include pneumonia, seizures, brain damage, and, in rare cases, death.

Prevention is primarily through vaccination, which is part of the recommended immunization schedule for children. A booster dose is also recommended for adolescents and adults to maintain immunity. Antibiotics can be used to treat Bordetella infections and help prevent the spread of the bacteria to others. However, antibiotics are most effective when started early in the course of the illness.

A "carbohydrate sequence" refers to the specific arrangement or order of monosaccharides (simple sugars) that make up a carbohydrate molecule, such as a polysaccharide or an oligosaccharide. Carbohydrates are often composed of repeating units of monosaccharides, and the sequence in which these units are arranged can have important implications for the function and properties of the carbohydrate.

For example, in glycoproteins (proteins that contain carbohydrate chains), the specific carbohydrate sequence can affect how the protein is processed and targeted within the cell, as well as its stability and activity. Similarly, in complex carbohydrates like starch or cellulose, the sequence of glucose units can determine whether the molecule is branched or unbranched, which can have implications for its digestibility and other properties.

Therefore, understanding the carbohydrate sequence is an important aspect of studying carbohydrate structure and function in biology and medicine.

HLA-DR antigens are a type of human leukocyte antigen (HLA) class II molecule that plays a crucial role in the immune system. They are found on the surface of antigen-presenting cells, such as dendritic cells, macrophages, and B lymphocytes. HLA-DR molecules present peptide antigens to CD4+ T cells, also known as helper T cells, thereby initiating an immune response.

HLA-DR antigens are highly polymorphic, meaning that there are many different variants of these molecules in the human population. This diversity allows for a wide range of potential peptide antigens to be presented and recognized by the immune system. HLA-DR antigens are encoded by genes located on chromosome 6 in the major histocompatibility complex (MHC) region.

In transplantation, HLA-DR compatibility between donor and recipient is an important factor in determining the success of the transplant. Incompatibility can lead to a heightened immune response against the transplanted organ or tissue, resulting in rejection. Additionally, certain HLA-DR types have been associated with increased susceptibility to autoimmune diseases, such as rheumatoid arthritis and multiple sclerosis.

Deoxy sugars, also known as deoxyriboses, are sugars that have one or more hydroxyl (-OH) groups replaced by a hydrogen atom. The most well-known deoxy sugar is deoxyribose, which is a component of DNA (deoxyribonucleic acid).

Deoxyribose is a pentose sugar, meaning it has five carbon atoms, and it differs from the related sugar ribose by having a hydrogen atom instead of a hydroxyl group at the 2' position. This structural difference affects the ability of DNA to form double-stranded helices through hydrogen bonding between complementary base pairs, which is critical for the storage and replication of genetic information.

Other deoxy sugars may also be important in biology, such as L-deoxyribose, a component of certain antibiotics, and various deoxyhexoses, which are found in some natural products and bacterial polysaccharides.

1. Receptors: In the context of physiology and medicine, receptors are specialized proteins found on the surface of cells or inside cells that detect and respond to specific molecules, known as ligands. These interactions can trigger a range of responses within the cell, such as starting a signaling pathway or changing the cell's behavior. There are various types of receptors, including ion channels, G protein-coupled receptors, and enzyme-linked receptors.

2. Antigen: An antigen is any substance (usually a protein) that can be recognized by the immune system, specifically by antibodies or T-cells, as foreign and potentially harmful. Antigens can be derived from various sources, such as bacteria, viruses, fungi, parasites, or even non-living substances like pollen, chemicals, or toxins. An antigen typically contains epitopes, which are the specific regions that antibodies or T-cell receptors recognize and bind to.

3. T-Cell: Also known as T lymphocytes, T-cells are a type of white blood cell that plays a crucial role in cell-mediated immunity, a part of the adaptive immune system. They are produced in the bone marrow and mature in the thymus gland. There are several types of T-cells, including CD4+ helper T-cells, CD8+ cytotoxic T-cells, and regulatory T-cells (Tregs). T-cells recognize antigens presented to them by antigen-presenting cells (APCs) via their surface receptors called the T-cell receptor (TCR). Once activated, T-cells can proliferate and differentiate into various effector cells that help eliminate infected or damaged cells.

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.

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.

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.

"Salmonella enterica" is a gram-negative, facultatively anaerobic bacterium that belongs to the family Enterobacteriaceae. It is a common cause of foodborne illnesses worldwide, often resulting in gastroenteritis, which is characterized by symptoms such as diarrhea, abdominal cramps, fever, and vomiting.

"Salmonella enterica" is further divided into several serovars or subspecies, with some of the most common ones causing human illness being Typhimurium and Enteritidis. These bacteria are typically transmitted to humans through contaminated food or water sources, such as raw or undercooked meat, poultry, eggs, and dairy products.

Once ingested, "Salmonella enterica" can colonize the gastrointestinal tract and release endotoxins that cause inflammation and damage to the intestinal lining. In some cases, the bacteria can spread to other parts of the body, leading to more severe and potentially life-threatening infections, particularly in individuals with weakened immune systems.

Preventing "Salmonella enterica" infections involves proper food handling and preparation practices, such as washing hands and surfaces thoroughly, cooking meats and eggs to appropriate temperatures, and avoiding cross-contamination between raw and cooked foods.

Proliferating Cell Nuclear Antigen (PCNA) is a protein that plays an essential role in the process of DNA replication and repair in eukaryotic cells. It functions as a cofactor for DNA polymerase delta, enhancing its activity during DNA synthesis. PCNA forms a sliding clamp around DNA, allowing it to move along the template and coordinate the actions of various enzymes involved in DNA metabolism.

PCNA is often used as a marker for cell proliferation because its levels increase in cells that are actively dividing or have been stimulated to enter the cell cycle. Immunostaining techniques can be used to detect PCNA and determine the proliferative status of tissues or cultures. In this context, 'proliferating' refers to the rapid multiplication of cells through cell division.

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.

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.

Histocompatibility antigens Class II are a group of cell surface proteins that play a crucial role in the immune system's response to foreign substances. They are expressed on the surface of various cells, including immune cells such as B lymphocytes, macrophages, dendritic cells, and activated T lymphocytes.

Class II histocompatibility antigens are encoded by the major histocompatibility complex (MHC) class II genes, which are located on chromosome 6 in humans. These antigens are composed of two non-covalently associated polypeptide chains, an alpha (α) and a beta (β) chain, which form a heterodimer. There are three main types of Class II histocompatibility antigens, known as HLA-DP, HLA-DQ, and HLA-DR.

Class II histocompatibility antigens present peptide antigens to CD4+ T helper cells, which then activate other immune cells, such as B cells and macrophages, to mount an immune response against the presented antigen. Because of their role in initiating an immune response, Class II histocompatibility antigens are important in transplantation medicine, where mismatches between donor and recipient can lead to rejection of the transplanted organ or tissue.

Prostate-Specific Antigen (PSA) is a glycoprotein enzyme produced by the epithelial cells of the prostate gland. It is primarily involved in liquefying semen after ejaculation, allowing sperm mobility.

In clinical medicine, PSA is used as a tumor marker, mainly for monitoring the treatment and recurrence of prostate cancer. Elevated levels of PSA can indicate inflammation, infection, benign prostatic hyperplasia (BPH), or prostate cancer. However, it's important to note that an elevated PSA level does not necessarily confirm cancer; further diagnostic tests like digital rectal examination, transrectal ultrasound, and prostate biopsy are often required for definitive diagnosis.

Doctors may also use PSA isoforms or derivatives, such as free PSA, total PSA, and PSA density, to help improve the specificity of cancer detection and differentiate between malignant and benign conditions.

1. Receptors: In the context of physiology and medicine, receptors are specialized proteins found on the surface of cells or inside cells that detect and respond to specific molecules, known as ligands. These interactions can trigger a variety of responses within the cell, such as starting a signaling cascade or changing the cell's metabolism. Receptors play crucial roles in various biological processes, including communication between cells, regulation of immune responses, and perception of senses.

2. Antigen: An antigen is any substance (usually a protein) that can be recognized by the adaptive immune system, specifically by B-cells and T-cells. Antigens can be derived from various sources, such as microorganisms (like bacteria, viruses, or fungi), pollen, dust mites, or even components of our own cells (for instance, in autoimmune diseases). An antigen's ability to stimulate an immune response is determined by its molecular structure and whether it can be recognized by the receptors on immune cells.

3. B-Cell: B-cells are a type of white blood cell that plays a critical role in the adaptive immune system, particularly in humoral immunity. They originate from hematopoietic stem cells in the bone marrow and are responsible for producing antibodies, which are proteins that recognize and bind to specific antigens. Each B-cell has receptors on its surface called B-cell receptors (BCRs) that can recognize a unique antigen. When a B-cell encounters its specific antigen, it becomes activated, undergoes proliferation, and differentiates into plasma cells that secrete large amounts of antibodies to neutralize or eliminate the antigen.

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.

Carbohydrate epimerases are a group of enzymes that catalyze the interconversion of specific stereoisomers (epimers) of carbohydrates by the reversible oxidation and reduction of carbon atoms, usually at the fourth or fifth position. These enzymes play important roles in the biosynthesis and modification of various carbohydrate-containing molecules, such as glycoproteins, proteoglycans, and glycolipids, which are involved in numerous biological processes including cell recognition, signaling, and adhesion.

The reaction catalyzed by carbohydrate epimerases involves the transfer of a hydrogen atom and a proton between two adjacent carbon atoms, leading to the formation of new stereochemical configurations at these positions. This process can result in the conversion of one epimer into another, thereby expanding the structural diversity of carbohydrates and their derivatives.

Carbohydrate epimerases are classified based on the type of substrate they act upon and the specific stereochemical changes they induce. Some examples include UDP-glucose 4-epimerase, which interconverts UDP-glucose and UDP-galactose; UDP-N-acetylglucosamine 2-epimerase, which converts UDP-N-acetylglucosamine to UDP-N-acetylmannosamine; and GDP-fucose synthase, which catalyzes the conversion of GDP-mannose to GDP-fucose.

Understanding the function and regulation of carbohydrate epimerases is crucial for elucidating their roles in various biological processes and developing strategies for targeting them in therapeutic interventions.

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.

"Salmonella enterica" serovar "Typhimurium" is a subspecies of the bacterial species Salmonella enterica, which is a gram-negative, facultatively anaerobic, rod-shaped bacterium. It is a common cause of foodborne illness in humans and animals worldwide. The bacteria can be found in a variety of sources, including contaminated food and water, raw meat, poultry, eggs, and dairy products.

The infection caused by Salmonella Typhimurium is typically self-limiting and results in gastroenteritis, which is characterized by symptoms such as diarrhea, abdominal cramps, fever, and vomiting. However, in some cases, the infection can spread to other parts of the body and cause more severe illness, particularly in young children, older adults, and people with weakened immune systems.

Salmonella Typhimurium is a major public health concern due to its ability to cause outbreaks of foodborne illness, as well as its potential to develop antibiotic resistance. Proper food handling, preparation, and storage practices can help prevent the spread of Salmonella Typhimurium and other foodborne pathogens.

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.

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.

Bacterial vaccines are types of vaccines that are created using bacteria or parts of bacteria as the immunogen, which is the substance that triggers an immune response in the body. The purpose of a bacterial vaccine is to stimulate the immune system to develop protection against specific bacterial infections.

There are several types of bacterial vaccines, including:

1. Inactivated or killed whole-cell vaccines: These vaccines contain entire bacteria that have been killed or inactivated through various methods, such as heat or chemicals. The bacteria can no longer cause disease, but they still retain the ability to stimulate an immune response.
2. Subunit, protein, or polysaccharide vaccines: These vaccines use specific components of the bacterium, such as proteins or polysaccharides, that are known to trigger an immune response. By using only these components, the vaccine can avoid using the entire bacterium, which may reduce the risk of adverse reactions.
3. Live attenuated vaccines: These vaccines contain live bacteria that have been weakened or attenuated so that they cannot cause disease but still retain the ability to stimulate an immune response. This type of vaccine can provide long-lasting immunity, but it may not be suitable for people with weakened immune systems.

Bacterial vaccines are essential tools in preventing and controlling bacterial infections, reducing the burden of diseases such as tuberculosis, pneumococcal disease, meningococcal disease, and Haemophilus influenzae type b (Hib) disease. They work by exposing the immune system to a harmless form of the bacteria or its components, which triggers the production of antibodies and memory cells that can recognize and fight off future infections with that same bacterium.

It's important to note that while vaccines are generally safe and effective, they may cause mild side effects such as pain, redness, or swelling at the injection site, fever, or fatigue. Serious side effects are rare but can occur, so it's essential to consult with a healthcare provider before receiving any vaccine.

CD15 is a type of antigen that is found on the surface of certain types of white blood cells called neutrophils and monocytes. It is also expressed on some types of cancer cells, including myeloid leukemia cells and some lymphomas. CD15 antigens are part of a group of molecules known as carbohydrate antigens because they contain sugar-like substances called carbohydrates.

CD15 antigens play a role in the immune system's response to infection and disease. They can be recognized by certain types of immune cells, such as natural killer (NK) cells and cytotoxic T cells, which can then target and destroy cells that express CD15 antigens. In cancer, the presence of CD15 antigens on the surface of cancer cells can make them more visible to the immune system, potentially triggering an immune response against the cancer.

CD15 antigens are also used as a marker in laboratory tests to help identify and classify different types of white blood cells and cancer cells. For example, CD15 staining is often used in the diagnosis of acute myeloid leukemia (AML) to distinguish it from other types of leukemia.

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.

Tumor-associated carbohydrate antigens (TACAs) are a type of tumor antigen that are expressed on the surface of cancer cells. These antigens are abnormal forms of carbohydrates, also known as glycans, which are attached to proteins and lipids on the cell surface.

TACAs are often overexpressed or expressed in a different form on cancer cells compared to normal cells. This makes them attractive targets for cancer immunotherapy because they can be recognized by the immune system as foreign and elicit an immune response. Some examples of TACAs include gangliosides, fucosylated glycans, and sialylated glycans.

Tumor-associated carbohydrate antigens have been studied as potential targets for cancer vaccines, antibody therapies, and other immunotherapeutic approaches. However, their use as targets for cancer therapy is still in the early stages of research and development.

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.

HLA-A2 antigen is a type of human leukocyte antigen (HLA) class I molecule, which is found on the surface of cells in our body. HLA molecules are responsible for presenting pieces of proteins (peptides) from inside the cell to the immune system's T-cells, helping them distinguish between "self" and "non-self" proteins.

HLA-A2 is one of the most common HLA class I antigens in the Caucasian population, with an estimated frequency of around 50%. It presents a variety of peptides to T-cells, including those derived from viruses and tumor cells. The presentation of these peptides can trigger an immune response, leading to the destruction of infected or malignant cells.

It is important to note that HLA typing is crucial in organ transplantation, as a mismatch between donor and recipient HLA antigens can lead to rejection of the transplanted organ. Additionally, HLA-A2 has been associated with certain autoimmune diseases and cancer types, making it an area of interest for researchers studying these conditions.

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.

CD8 antigens are a type of protein found on the surface of certain immune cells called cytotoxic T lymphocytes or cytotoxic T cells. These cells play a critical role in the adaptive immune response, which is the specific and targeted response of the immune system to foreign substances (antigens) that invade the body.

CD8 antigens help cytotoxic T cells recognize and respond to infected or abnormal cells, such as those that have been infected by a virus or have become cancerous. When a cytotoxic T cell encounters a cell displaying a specific antigen bound to a CD8 molecule, it becomes activated and releases toxic substances that can kill the target cell.

CD8 antigens are also known as cluster of differentiation 8 antigens or CD8 receptors. They belong to a larger family of proteins called major histocompatibility complex class I (MHC class I) molecules, which present antigens to T cells and play a crucial role in the immune system's ability to distinguish between self and non-self.

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.

Agglutination is a medical term that refers to the clumping together of particles, such as cells, bacteria, or precipitates, in a liquid medium. It most commonly occurs due to the presence of antibodies in the fluid that bind to specific antigens on the surface of the particles, causing them to adhere to one another and form visible clumps.

In clinical laboratory testing, agglutination is often used as a diagnostic tool to identify the presence of certain antibodies or antigens in a patient's sample. For example, a common application of agglutination is in blood typing, where the presence of specific antigens on the surface of red blood cells causes them to clump together when mixed with corresponding antibodies.

Agglutination can also occur in response to certain infectious agents, such as bacteria or viruses, that display antigens on their surface. In these cases, the agglutination reaction can help diagnose an infection and guide appropriate treatment.

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 group antigens are molecular markers found on the surface of red blood cells (RBCs) and sometimes other types of cells in the body. These antigens are proteins, carbohydrates, or glycoproteins that can stimulate an immune response when foreign antigens are introduced into the body.

There are several different blood group systems, but the most well-known is the ABO system, which includes A, B, AB, and O blood groups. The antigens in this system are called ABO antigens. Individuals with type A blood have A antigens on their RBCs, those with type B blood have B antigens, those with type AB blood have both A and B antigens, and those with type O blood have neither A nor B antigens.

Another important blood group system is the Rh system, which includes the D antigen. Individuals who have this antigen are considered Rh-positive, while those who do not have it are considered Rh-negative.

Blood group antigens can cause complications during blood transfusions and pregnancy if there is a mismatch between the donor's or fetus's antigens and the recipient's antibodies. For example, if a person with type A blood receives type B blood, their anti-B antibodies will attack the foreign B antigens on the donated RBCs, causing a potentially life-threatening transfusion reaction. Similarly, if an Rh-negative woman becomes pregnant with an Rh-positive fetus, her immune system may produce anti-D antibodies that can cross the placenta and attack the fetal RBCs, leading to hemolytic disease of the newborn.

It is important for medical professionals to determine a patient's blood group before performing a transfusion or pregnancy-related procedures to avoid these complications.

Hepatitis B Surface Antigens (HBsAg) are proteins found on the surface of the Hepatitis B virus. They are present in the blood of individuals infected with the Hepatitis B virus and are used as a marker for the presence of a current Hepatitis B infection. The detection of HBsAg in the blood indicates that an individual is infectious and can transmit the virus to others. It is typically used in diagnostic tests to detect and diagnose Hepatitis B infections, monitor treatment response, and assess the risk of transmission.

CD3 antigens are a group of proteins found on the surface of T-cells, which are a type of white blood cell that plays a central role in the immune response. The CD3 antigens are composed of several different subunits (ε, δ, γ, and α) that associate to form the CD3 complex, which is involved in T-cell activation and signal transduction.

The CD3 complex is associated with the T-cell receptor (TCR), which recognizes and binds to specific antigens presented by antigen-presenting cells. When the TCR binds to an antigen, it triggers a series of intracellular signaling events that lead to T-cell activation and the initiation of an immune response.

CD3 antigens are important targets for immunotherapy in some diseases, such as certain types of cancer. For example, monoclonal antibodies that target CD3 have been developed to activate T-cells and enhance their ability to recognize and destroy tumor cells. However, CD3-targeted therapies can also cause side effects, such as cytokine release syndrome, which can be serious or life-threatening in some cases.

Glycosyltransferases are a group of enzymes that play a crucial role in the synthesis of glycoconjugates, which are complex carbohydrate structures found on the surface of cells and in various biological fluids. These enzymes catalyze the transfer of a sugar moiety from an activated donor molecule to an acceptor molecule, resulting in the formation of a glycosidic bond.

The donor molecule is typically a nucleotide sugar, such as UDP-glucose or CMP-sialic acid, which provides the energy required for the transfer reaction. The acceptor molecule can be a wide range of substrates, including proteins, lipids, and other carbohydrates.

Glycosyltransferases are highly specific in their activity, with each enzyme recognizing a particular donor and acceptor pair. This specificity allows for the precise regulation of glycan structures, which have been shown to play important roles in various biological processes, including cell recognition, signaling, and adhesion.

Defects in glycosyltransferase function can lead to a variety of genetic disorders, such as congenital disorders of glycosylation (CDG), which are characterized by abnormal glycan structures and a wide range of clinical manifestations, including developmental delay, neurological impairment, and multi-organ dysfunction.

HLA-A antigens are a type of human leukocyte antigen (HLA) found on the surface of cells in our body. They are proteins that play an important role in the immune system by helping the body recognize and distinguish its own cells from foreign substances such as viruses, bacteria, and transplanted organs.

The HLA-A antigens are part of the major histocompatibility complex (MHC) class I molecules, which present peptide fragments from inside the cell to CD8+ T cells, also known as cytotoxic T lymphocytes (CTLs). The CTLs then recognize and destroy any cells that display foreign or abnormal peptides on their HLA-A antigens.

Each person has a unique set of HLA-A antigens, which are inherited from their parents. These antigens can vary widely between individuals, making it important to match HLA types in organ transplantation to reduce the risk of rejection. Additionally, certain HLA-A antigens have been associated with increased susceptibility or resistance to various diseases, including autoimmune disorders and infectious diseases.

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.

Galactose is a simple sugar or monosaccharide that is a constituent of lactose, the disaccharide found in milk and dairy products. It's structurally similar to glucose but with a different chemical structure, and it plays a crucial role in various biological processes.

Galactose can be metabolized in the body through the action of enzymes such as galactokinase, galactose-1-phosphate uridylyltransferase, and UDP-galactose 4'-epimerase. Inherited deficiencies in these enzymes can lead to metabolic disorders like galactosemia, which can cause serious health issues if not diagnosed and treated promptly.

In summary, Galactose is a simple sugar that plays an essential role in lactose metabolism and other biological processes.

Histocompatibility antigens, class I 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." These antigens are composed of three polypeptides - two heavy chains and one light chain - and are encoded by genes in the major histocompatibility complex (MHC) on chromosome 6 in humans.

Class I MHC molecules present peptide fragments from inside the cell to CD8+ T cells, also known as cytotoxic T cells. This presentation allows the immune system to detect and destroy cells that have been infected by viruses or other intracellular pathogens, or that have become cancerous.

There are three main types of class I MHC molecules in humans: HLA-A, HLA-B, and HLA-C. The term "HLA" stands for human leukocyte antigen, which reflects the original identification of these proteins on white blood cells (leukocytes). The genes encoding these molecules are highly polymorphic, meaning there are many different variants in the population, and matching HLA types is essential for successful organ transplantation to minimize the risk of rejection.

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.

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.

Bacillary dysentery is a type of dysentery caused by the bacterium Shigella. It is characterized by the inflammation of the intestines, particularly the colon, resulting in diarrhea that may contain blood and mucus. The infection is typically spread through contaminated food or water, or close contact with an infected person. Symptoms usually appear within 1-4 days after exposure and can include abdominal cramps, fever, nausea, vomiting, and tenesmus (the strong, frequent urge to have a bowel movement). In severe cases, bacillary dysentery can lead to dehydration, electrolyte imbalance, and other complications. Treatment typically involves antibiotics to kill the bacteria, as well as fluid replacement to prevent dehydration.

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.

Galactans are a type of complex carbohydrates known as oligosaccharides that are composed of galactose molecules. They can be found in certain plants, including beans, lentils, and some fruits and vegetables. In the human body, galactans are not digestible and can reach the colon intact, where they may serve as a substrate for fermentation by gut bacteria. This can lead to the production of short-chain fatty acids, which have been shown to have various health benefits. However, in some individuals with irritable bowel syndrome or other functional gastrointestinal disorders, consumption of galactans may cause digestive symptoms such as bloating, gas, and diarrhea.

HLA-D antigens, also known as HLA class II antigens, are a group of proteins found on the surface of cells that play an important role in the immune system. "HLA" stands for Human Leukocyte Antigen, which is a part of the major histocompatibility complex (MHC) in humans.

HLA-D antigens are primarily expressed by immune cells such as B lymphocytes, macrophages, and dendritic cells, but they can also be found on other cell types under certain conditions. These antigens help the immune system distinguish between "self" and "non-self" by presenting pieces of proteins (peptides) from both inside and outside the cell to T lymphocytes, a type of white blood cell that is crucial for mounting an immune response.

HLA-D antigens are divided into three subtypes: HLA-DP, HLA-DQ, and HLA-DR. Each subtype has a specific function in presenting peptides to T lymphocytes. The genes that encode HLA-D antigens are highly polymorphic, meaning there are many different variations of these genes in the population. This genetic diversity allows for a better match between an individual's immune system and the wide variety of pathogens they may encounter.

Abnormalities in HLA-D antigens have been associated with several autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes, and multiple sclerosis. Additionally, certain variations in HLA-D genes can influence the severity of infectious diseases, such as HIV/AIDS and hepatitis C.

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.

Antigen receptors are specialized proteins found on the surface of immune cells, particularly B cells and T cells. These receptors are responsible for recognizing and binding to specific antigens, which are foreign substances such as proteins, carbohydrates, or lipids that stimulate an immune response.

B cell receptors (BCRs) are membrane-bound antibodies that recognize and bind to native antigens. When a BCR binds to its specific antigen, it triggers a series of intracellular signals that lead to the activation and differentiation of the B cell into an antibody-secreting plasma cell.

T cell receptors (TCRs) are membrane-bound proteins found on T cells that recognize and bind to antigens presented in the context of major histocompatibility complex (MHC) molecules on the surface of antigen-presenting cells. TCRs can distinguish between self and non-self antigens, allowing T cells to mount an immune response against infected or cancerous cells while sparing healthy cells.

Overall, antigen receptors play a critical role in the adaptive immune system's ability to recognize and respond to a wide variety of foreign substances.

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.

CD45 is a protein that is found on the surface of many types of white blood cells, including T-cells, B-cells, and natural killer (NK) cells. It is also known as leukocyte common antigen because it is present on almost all leukocytes. CD45 is a tyrosine phosphatase that plays a role in regulating the activity of various proteins involved in cell signaling pathways.

As an antigen, CD45 is used as a marker to identify and distinguish different types of white blood cells. It has several isoforms that are generated by alternative splicing of its mRNA, resulting in different molecular weights. The size of the CD45 isoform can be used to distinguish between different subsets of T-cells and B-cells.

CD45 is an important molecule in the immune system, and abnormalities in its expression or function have been implicated in various diseases, including autoimmune disorders and cancer.

Shigella is a genus of Gram-negative, facultatively anaerobic, rod-shaped bacteria that are primarily responsible for causing shigellosis, also known as bacillary dysentery. These pathogens are highly infectious and can cause severe gastrointestinal illness in humans through the consumption of contaminated food or water, or direct contact with an infected person's feces.

There are four main species of Shigella: S. dysenteriae, S. flexneri, S. boydii, and S. sonnei. Each species has distinct serotypes that differ in their epidemiology, clinical presentation, and antibiotic susceptibility patterns. The severity of shigellosis can range from mild diarrhea to severe dysentery with abdominal cramps, fever, and tenesmus (the strong, frequent urge to defecate). In some cases, Shigella infections may lead to complications such as bacteremia, seizures, or hemolytic uremic syndrome.

Preventive measures include maintaining good personal hygiene, proper food handling and preparation, access to clean water, and adequate sanitation facilities. Antibiotic treatment is generally recommended for severe cases of shigellosis, but the emergence of antibiotic-resistant strains has become a growing concern in recent years.

Hepatitis B antigens are proteins or particles present on the surface (HBsAg) or inside (HBcAg, HBeAg) the hepatitis B virus.

1. HBsAg (Hepatitis B surface antigen): This is a protein found on the outer surface of the hepatitis B virus. Its presence in the blood indicates an active infection with hepatitis B virus. It's also used as a marker to diagnose hepatitis B infection and monitor treatment response.

2. HBcAg (Hepatitis B core antigen): This is a protein found inside the hepatitis B virus core. It's not usually detected in the blood, but its antibodies (anti-HBc) are used to diagnose past or present hepatitis B infection.

3. HBeAg (Hepatitis B e antigen): This is a protein found inside the hepatitis B virus core and is associated with viral replication. Its presence in the blood indicates high levels of viral replication, increased infectivity, and higher risk of liver damage. It's used to monitor disease progression and treatment response.

These antigens play a crucial role in the diagnosis, management, and prevention of hepatitis B infection.

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.

Salmonella typhi is a bacterium that causes typhoid fever, a severe and sometimes fatal infectious disease. It is a human-specific pathogen, which means it only infects humans and is not carried in animals or birds. The bacteria are spread through the fecal-oral route, often through contaminated food or water. Once ingested, Salmonella typhi can invade the intestinal tract, causing symptoms such as high fever, headache, abdominal pain, constipation, and rose-colored spots on the chest. If left untreated, typhoid fever can lead to serious complications, including intestinal perforation, bacteremia, and death.

CD4 antigens, also known as CD4 proteins or CD4 molecules, are a type of cell surface receptor found on certain immune cells, including T-helper cells and monocytes. They play a critical role in the immune response by binding to class II major histocompatibility complex (MHC) molecules on the surface of antigen-presenting cells and helping to activate T-cells. CD4 antigens are also the primary target of the human immunodeficiency virus (HIV), which causes AIDS, leading to the destruction of CD4-positive T-cells and a weakened immune system.

"Pseudomonas aeruginosa" is a medically important, gram-negative, rod-shaped bacterium that is widely found in the environment, such as in soil, water, and on plants. It's an opportunistic pathogen, meaning it usually doesn't cause infection in healthy individuals but can cause severe and sometimes life-threatening infections in people with weakened immune systems, burns, or chronic lung diseases like cystic fibrosis.

P. aeruginosa is known for its remarkable ability to resist many antibiotics and disinfectants due to its intrinsic resistance mechanisms and the acquisition of additional resistance determinants. It can cause various types of infections, including respiratory tract infections, urinary tract infections, gastrointestinal infections, dermatitis, and severe bloodstream infections known as sepsis.

The bacterium produces a variety of virulence factors that contribute to its pathogenicity, such as exotoxins, proteases, and pigments like pyocyanin and pyoverdine, which aid in iron acquisition and help the organism evade host immune responses. Effective infection control measures, appropriate use of antibiotics, and close monitoring of high-risk patients are crucial for managing P. aeruginosa infections.

CD1 antigens are a group of molecules found on the surface of certain immune cells, including dendritic cells and B cells. They play a role in the immune system by presenting lipid antigens to T cells, which helps initiate an immune response against foreign substances such as bacteria and viruses. CD1 molecules are distinct from other antigen-presenting molecules like HLA because they present lipids rather than peptides. There are five different types of CD1 molecules (CD1a, CD1b, CD1c, CD1d, and CD1e) that differ in their tissue distribution and the types of lipid antigens they present.

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.

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.

Nucleoside diphosphate sugars (NDP-sugars) are essential activated sugars that play a crucial role in the biosynthesis of complex carbohydrates, such as glycoproteins and glycolipids. They consist of a sugar molecule linked to a nucleoside diphosphate, which is formed from a nucleotide by removal of one phosphate group.

NDP-sugars are created through the action of enzymes called nucleoside diphosphate sugars synthases or transferases, which transfer a sugar molecule from a donor to a nucleoside diphosphate, forming an NDP-sugar. The resulting NDP-sugar can then be used as a substrate for various glycosyltransferases that catalyze the addition of sugars to other molecules, such as proteins or lipids.

NDP-sugars are involved in many important biological processes, including cell signaling, protein targeting, and immune response. They also play a critical role in maintaining the structural integrity of cells and tissues.

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.

"Vibrio cholerae" is a species of gram-negative, comma-shaped bacteria that is the causative agent of cholera, a diarrheal disease. It can be found in aquatic environments, such as estuaries and coastal waters, and can sometimes be present in raw or undercooked seafood. The bacterium produces a toxin called cholera toxin, which causes the profuse, watery diarrhea that is characteristic of cholera. In severe cases, cholera can lead to dehydration and electrolyte imbalances, which can be life-threatening if not promptly treated with oral rehydration therapy or intravenous fluids.

HLA-B antigens are human leukocyte antigen (HLA) proteins found on the surface of cells that play an important role in the body's immune system. They are part of the major histocompatibility complex (MHC) class I molecules, which present pieces of proteins from inside the cell to T-cells, a type of white blood cell involved in immune responses.

HLA-B antigens are highly polymorphic, meaning that there are many different variations or alleles of this gene in the human population. This genetic diversity allows for a wide range of potential HLA-B proteins to be expressed, which can help recognize and respond to a variety of foreign substances, such as viruses and cancer cells.

The HLA-B antigens are inherited from both parents, and an individual may express one or two different HLA-B antigens depending on their genetic makeup. The specific combination of HLA-B antigens that a person expresses can have implications for their susceptibility to certain diseases, as well as their compatibility with organ transplants.

"Serratia marcescens" is a medically significant species of gram-negative, facultatively anaerobic, motile bacillus bacteria that belongs to the family Enterobacteriaceae. It is commonly found in soil, water, and in the gastrointestinal tracts of humans and animals. The bacteria are known for their ability to produce a red pigment called prodigiosin, which gives them a distinctive pink color on many types of laboratory media.

"Serratia marcescens" can cause various types of infections, including respiratory tract infections, urinary tract infections, wound infections, and bacteremia (bloodstream infections). It is also known to be an opportunistic pathogen, which means that it primarily causes infections in individuals with weakened immune systems, such as those with chronic illnesses or who are undergoing medical treatments that suppress the immune system.

In healthcare settings, "Serratia marcescens" can cause outbreaks of infection, particularly in patients who are hospitalized for extended periods of time. It is resistant to many commonly used antibiotics, which makes it difficult to treat and control the spread of infections caused by this organism.

In addition to its medical significance, "Serratia marcescens" has also been used as a model organism in various areas of microbiological research, including studies on bacterial motility, biofilm formation, and antibiotic resistance.

"Klebsiella pneumoniae" is a medical term that refers to a type of bacteria belonging to the family Enterobacteriaceae. It's a gram-negative, encapsulated, non-motile, rod-shaped bacterium that can be found in various environments, including soil, water, and the gastrointestinal tracts of humans and animals.

"Klebsiella pneumoniae" is an opportunistic pathogen that can cause a range of infections, particularly in individuals with weakened immune systems or underlying medical conditions. It's a common cause of healthcare-associated infections, such as pneumonia, urinary tract infections, bloodstream infections, and wound infections.

The bacterium is known for its ability to produce a polysaccharide capsule that makes it resistant to phagocytosis by white blood cells, allowing it to evade the host's immune system. Additionally, "Klebsiella pneumoniae" has developed resistance to many antibiotics, making infections caused by this bacterium difficult to treat and a growing public health concern.

Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria that can be recognized by the immune system and provoke an immune response. In the context of differentiation, antigens refer to specific markers that identify the developmental stage or lineage of a cell.

Differentiation antigens are proteins or carbohydrates expressed on the surface of cells during various stages of differentiation, which can be used to distinguish between cells at different maturation stages or of different cell types. These antigens play an essential role in the immune system's ability to recognize and respond to abnormal or infected cells while sparing healthy cells.

Examples of differentiation antigens include:

1. CD (cluster of differentiation) molecules: A group of membrane proteins used to identify and define various cell types, such as T cells, B cells, natural killer cells, monocytes, and granulocytes.
2. Lineage-specific antigens: Antigens that are specific to certain cell lineages, such as CD3 for T cells or CD19 for B cells.
3. Maturation markers: Antigens that indicate the maturation stage of a cell, like CD34 and CD38 on hematopoietic stem cells.

Understanding differentiation antigens is crucial in immunology, cancer research, transplantation medicine, and vaccine development.

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.

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.

'Bordetella bronchiseptica' is a gram-negative, aerobic bacterium that primarily colonizes the respiratory tract of animals, including dogs, cats, and rabbits. It can also cause respiratory infections in humans, particularly in individuals with compromised immune systems or underlying lung diseases.

The bacterium produces several virulence factors, such as adhesins, toxins, and proteases, which allow it to attach to and damage the ciliated epithelial cells lining the respiratory tract. This can lead to inflammation, bronchitis, pneumonia, and other respiratory complications.

'Bordetella bronchiseptica' is closely related to 'Bordetella pertussis', the bacterium that causes whooping cough in humans. However, while 'Bordetella pertussis' is highly adapted to infecting humans, 'Bordetella bronchiseptica' has a broader host range and can cause disease in a variety of animal species.

In animals, 'Bordetella bronchiseptica' is often associated with kennel cough, a highly contagious respiratory infection that spreads rapidly among dogs in close quarters, such as boarding facilities or dog parks. Vaccines are available to prevent kennel cough caused by 'Bordetella bronchiseptica', and they are often recommended for dogs that are at high risk of exposure.

Rhizobium etli is a gram-negative, aerobic, motile, non-spore forming bacteria that belongs to the Rhizobiaceae family. It has the ability to fix atmospheric nitrogen in a symbiotic relationship with certain leguminous plants, particularly common bean (Phaseolus vulgaris). This bacterium infects the roots of these plants and forms nodules where it converts nitrogen gas into ammonia, a form that can be used by the plant for growth. The nitrogen-fixing ability of Rhizobium etli makes it an important bacteria in agriculture and environmental science.

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.

Lipid A is the biologically active component of lipopolysaccharides (LPS), which are found in the outer membrane of Gram-negative bacteria. It is responsible for the endotoxic activity of LPS and plays a crucial role in the pathogenesis of gram-negative bacterial infections. Lipid A is a glycophosphatidylinositol (GPI) anchor, consisting of a glucosamine disaccharide backbone with multiple fatty acid chains and phosphate groups attached to it. It can induce the release of proinflammatory cytokines, fever, and other symptoms associated with sepsis when introduced into the bloodstream.

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.

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.

Hemagglutination is a medical term that refers to the agglutination or clumping together of red blood cells (RBCs) in the presence of an agglutinin, which is typically a protein or a polysaccharide found on the surface of certain viruses, bacteria, or incompatible blood types.

In simpler terms, hemagglutination occurs when the agglutinin binds to specific antigens on the surface of RBCs, causing them to clump together and form visible clumps or aggregates. This reaction is often used in diagnostic tests to identify the presence of certain viruses or bacteria, such as influenza or HIV, by mixing a sample of blood or other bodily fluid with a known agglutinin and observing whether hemagglutination occurs.

Hemagglutination inhibition (HI) assays are also commonly used to measure the titer or concentration of antibodies in a serum sample, by adding serial dilutions of the serum to a fixed amount of agglutinin and observing the highest dilution that still prevents hemagglutination. This can help determine whether a person has been previously exposed to a particular pathogen and has developed immunity to it.

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.

MART-1, also known as Melanoma Antigen Recognized by T-Cells 1 or Melan-A, is a protein that is primarily found in melanocytes, which are the pigment-producing cells located in the skin, eyes, and hair follicles. It is a member of the family of antigens called melanoma differentiation antigens (MDAs) that are specifically expressed in melanocytes and melanomas. MART-1 is considered a tumor-specific antigen because it is overexpressed in melanoma cells compared to normal cells, making it an attractive target for immunotherapy.

MART-1 is presented on the surface of melanoma cells in complex with major histocompatibility complex (MHC) class I molecules, where it can be recognized by cytotoxic T lymphocytes (CTLs). This recognition triggers an immune response that can lead to the destruction of melanoma cells. MART-1 has been widely used as a target in various immunotherapy approaches, including cancer vaccines and adoptive cell transfer therapies, with the goal of enhancing the body's own immune system to recognize and eliminate melanoma cells.

Hexoses are simple sugars (monosaccharides) that contain six carbon atoms. The most common hexoses include glucose, fructose, and galactose. These sugars play important roles in various biological processes, such as serving as energy sources or forming complex carbohydrates like starch and cellulose. Hexoses are essential for the structure and function of living organisms, including humans.

Hexosyltransferases are a group of enzymes that catalyze the transfer of a hexose (a type of sugar molecule made up of six carbon atoms) from a donor molecule to an acceptor molecule. This transfer results in the formation of a glycosidic bond between the two molecules.

Hexosyltransferases are involved in various biological processes, including the biosynthesis of complex carbohydrates, such as glycoproteins and glycolipids, which play important roles in cell recognition, signaling, and communication. These enzymes can transfer a variety of hexose sugars, including glucose, galactose, mannose, fucose, and N-acetylglucosamine, to different acceptor molecules, such as proteins, lipids, or other carbohydrates.

Hexosyltransferases are classified based on the type of donor molecule they use, the type of sugar they transfer, and the type of glycosidic bond they form. Some examples of hexosyltransferases include:

* Glycosyltransferases (GTs): These enzymes transfer a sugar from an activated donor molecule, such as a nucleotide sugar, to an acceptor molecule. GTs are involved in the biosynthesis of various glycoconjugates, including proteoglycans, glycoproteins, and glycolipids.
* Fucosyltransferases (FUTs): These enzymes transfer fucose, a type of hexose sugar, to an acceptor molecule. FUTs are involved in the biosynthesis of various glycoconjugates, including blood group antigens and Lewis antigens.
* Galactosyltransferases (GALTs): These enzymes transfer galactose, another type of hexose sugar, to an acceptor molecule. GALTs are involved in the biosynthesis of various glycoconjugates, including lactose in milk and gangliosides in the brain.
* Mannosyltransferases (MTs): These enzymes transfer mannose, a type of hexose sugar, to an acceptor molecule. MTs are involved in the biosynthesis of various glycoconjugates, including N-linked glycoproteins and yeast cell walls.

Hexosyltransferases play important roles in many biological processes, including cell recognition, signaling, and adhesion. Dysregulation of these enzymes has been implicated in various diseases, such as cancer, inflammation, and neurodegenerative disorders. Therefore, understanding the mechanisms of hexosyltransferases is crucial for developing new 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.

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.

Keratoconjunctivitis is a medical term that refers to the inflammation of both the cornea (the clear, outer layer at the front of the eye) and the conjunctiva (the mucous membrane that covers the inner surface of the eyelids and the white part of the eye).

The condition can cause symptoms such as redness, pain, sensitivity to light, watery eyes, and a gritty or burning sensation in the eyes. Keratoconjunctivitis can be caused by various factors, including viral or bacterial infections, allergies, or environmental irritants like dust, smoke, or chemical fumes.

Treatment for keratoconjunctivitis depends on the underlying cause of the condition and may include medications such as antibiotics, antivirals, or anti-inflammatory agents to reduce inflammation and relieve symptoms. In some cases, artificial tears or lubricants may also be recommended to help keep the eyes moist and comfortable.

'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.

HIV antigens refer to the proteins present on the surface or within the human immunodeficiency virus (HIV), which can stimulate an immune response in the infected individual. These antigens are recognized by the host's immune system, specifically by CD4+ T cells and antibodies, leading to their activation and production. Two significant HIV antigens are the HIV-1 p24 antigen and the gp120/gp41 envelope proteins. The p24 antigen is a capsid protein found within the viral particle, while the gp120/gp41 complex forms the viral envelope and facilitates viral entry into host cells. Detection of HIV antigens in clinical settings, such as in the ELISA or Western blot tests, helps diagnose HIV infection and monitor disease progression.

CD80 (also known as B7-1) is a cell surface protein that functions as a costimulatory molecule in the immune system. It is primarily expressed on antigen presenting cells such as dendritic cells, macrophages, and B cells. CD80 binds to the CD28 receptor on T cells, providing a critical second signal necessary for T cell activation and proliferation. This interaction plays a crucial role in the initiation of an effective immune response against pathogens and tumors.

CD80 can also interact with another receptor called CTLA-4 (cytotoxic T lymphocyte antigen 4), which is expressed on activated T cells. The binding of CD80 to CTLA-4 delivers a negative signal that helps regulate the immune response and prevent overactivation, contributing to the maintenance of self-tolerance and preventing autoimmunity.

In summary, CD80 is an important antigen involved in the regulation of the adaptive immune response by modulating T cell activation and proliferation through its interactions with CD28 and CTLA-4 receptors.

Synthetic vaccines are artificially produced, designed to stimulate an immune response and provide protection against specific diseases. Unlike traditional vaccines that are derived from weakened or killed pathogens, synthetic vaccines are created using synthetic components, such as synthesized viral proteins, DNA, or RNA. These components mimic the disease-causing agent and trigger an immune response without causing the actual disease. The use of synthetic vaccines offers advantages in terms of safety, consistency, and scalability in production, making them valuable tools for preventing infectious diseases.

I'm sorry for any confusion, but "Hydro-Lyases" is not a recognized medical term or category in biochemistry. It seems like there might be a misunderstanding or a typo in the term.

In biochemistry, "lyases" are enzymes that catalyze the removal of groups from substrates by means other than hydrolysis or oxidation, often forming a double bond or a ring-forming reaction. They are classified and named based on the type of bond they break.

If you meant to ask about a specific enzyme or reaction, could you please provide more context or clarify the term? I'd be happy to help further with accurate information.

Epstein-Barr virus nuclear antigens (EBV NA) are proteins found inside the nucleus of cells that have been infected with the Epstein-Barr virus (EBV). EBV is a type of herpesvirus that is best known as the cause of infectious mononucleosis (also known as "mono" or "the kissing disease").

There are two main types of EBV NA: EBNA-1 and EBNA-2. These proteins play a role in the replication and survival of the virus within infected cells. They can be detected using laboratory tests, such as immunofluorescence assays or Western blotting, to help diagnose EBV infection or detect the presence of EBV-associated diseases, such as certain types of lymphoma and nasopharyngeal carcinoma.

EBNA-1 is essential for the maintenance and replication of the EBV genome within infected cells, while EBNA-2 activates viral gene expression and modulates the host cell's immune response to promote virus survival. Both proteins are considered potential targets for the development of antiviral therapies and vaccines against EBV infection.

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.

CD19 is a type of protein found on the surface of B cells, which are a type of white blood cell that plays a key role in the body's immune response. CD19 is a marker that helps identify and distinguish B cells from other types of cells in the body. It is also a target for immunotherapy in certain diseases, such as B-cell malignancies.

An antigen is any substance that can stimulate an immune response, particularly the production of antibodies. In the context of CD19, antigens refer to substances that can bind to CD19 and trigger a response from the immune system. This can include proteins, carbohydrates, or other molecules found on the surface of bacteria, viruses, or cancer cells.

Therefore, 'antigens, CD19' refers to any substances that can bind to the CD19 protein on B cells and trigger an immune response. These antigens may be used in the development of immunotherapies for the treatment of B-cell malignancies or other diseases.

Heptoses are rare sugars that contain seven carbons in their structure. They are not as common as monosaccharides with 5 or 6 carbons, such as ribose or glucose. An example of a heptose is sedoheptulose, which can be found in some plants and honey. Heptoses can play a role in various biological processes, including cell signaling and metabolism, but they are not as widely studied or well-understood as other types of sugars.

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.

"Providencia" is a term that refers to a type of bacteria that can cause infections in humans. The scientific name for this bacterium is "Providencia stuartii." It is part of the Enterobacteriaceae family and is commonly found in the gastrointestinal tract of humans and animals.

Providencia stuartii can cause a variety of infections, including urinary tract infections, wound infections, and bloodstream infections. It is often resistant to many antibiotics, which can make it difficult to treat. People who are hospitalized, have weakened immune systems, or use catheters are at increased risk for Providencia infections.

It's important to note that while "Providencia" refers to a specific type of bacteria, the term is not typically used in medical diagnoses or treatment. Instead, healthcare providers would specify the type of infection and the name of the bacterium causing it.

'Actinobacillus pleuropneumoniae' is a gram-negative, rod-shaped bacterium that primarily affects the respiratory system of pigs, causing a disease known as porcine pleuropneumonia. This disease is associated with severe respiratory signs, including coughing, difficulty breathing, and high fever, and can lead to significant economic losses in the swine industry.

The bacterium is typically transmitted through direct contact with infected pigs or contaminated fomites, and it can also be spread through aerosolized droplets. Once inside the host, 'Actinobacillus pleuropneumoniae' produces a number of virulence factors that allow it to evade the immune system and cause tissue damage.

Effective control and prevention strategies for porcine pleuropneumonia include vaccination, biosecurity measures, and antibiotic treatment. However, antibiotic resistance is an emerging concern in the management of this disease, highlighting the need for continued research and development of new control strategies.

Cholera is an infectious disease caused by the bacterium Vibrio cholerae, which is usually transmitted through contaminated food or water. The main symptoms of cholera are profuse watery diarrhea, vomiting, and dehydration, which can lead to electrolyte imbalances, shock, and even death if left untreated. Cholera remains a significant public health concern in many parts of the world, particularly in areas with poor sanitation and hygiene. The disease is preventable through proper food handling, safe water supplies, and improved sanitation, as well as vaccination for those at high risk.

Hepatitis B core antigen (HBcAg) is a protein found in the core of the hepatitis B virus (HBV). It is present during active replication of the virus and plays a crucial role in the formation of the viral capsid or core. The antibodies produced against HBcAg (anti-HBc) can be detected in the blood, which serves as a marker for current or past HBV infection. It is important to note that HBcAg itself is not detectable in the blood because it is confined within the viral particle. However, during the serological testing of hepatitis B, the detection of anti-HBc IgM indicates a recent acute infection, while the presence of anti-HBc IgG suggests either a past resolved infection or an ongoing chronic infection.

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.

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.

UTP-Glucose-1-Phosphate Uridylyltransferase is an enzyme that catalyzes the reaction to form UDP-glucose from UTP and glucose-1-phosphate. This reaction plays a crucial role in the biosynthesis of various carbohydrates, glycoproteins, and glycolipids in the body. The enzyme is also known as UDP-glucose pyrophosphorylase or simply as UGPase.

The systematic name for this enzyme is glucose-1-phosphate:UTP uridylyltransferase, and its reaction can be represented as follows:
UTP + glucose-1-phosphate ⇌ UDP-glucose + pyrophosphate

The enzyme is widely distributed in nature and is found in various organisms, including bacteria, plants, and animals. In humans, UGPase is present in multiple tissues, such as the liver, kidney, and brain. Defects in this enzyme can lead to several metabolic disorders, highlighting its importance in maintaining normal bodily functions.

UDP-glucose 4-epimerase (UGE) is an enzyme that catalyzes the reversible interconversion of UDP-galactose and UDP-glucose, two important nucleotide sugars involved in carbohydrate metabolism. This enzyme plays a crucial role in maintaining the balance between these two molecules, which are essential for the synthesis of various glycoconjugates, such as glycoproteins and proteoglycans. UGE is widely distributed in nature and has been identified in various organisms, including humans. In humans, deficiency or mutations in this enzyme can lead to a rare genetic disorder known as galactosemia, which is characterized by an impaired ability to metabolize the sugar galactose, resulting in several health issues.

I'm sorry for any confusion, but "Inovirus" is not a recognized term in current medical or scientific nomenclature. It seems there might be some mistake, as it is not listed in any major virology or medical databases. Inoviruses are actually a group of filamentous bacteriophages (viruses that infect bacteria) with a unique structure and replication strategy. If you have any more context or details about where you encountered this term, I'd be happy to help further!

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.

CD40 is a type of protein known as a tumor necrosis factor receptor that is found on the surface of various cells in the body, including B cells, dendritic cells, and activated T cells. It plays an important role in the immune system by interacting with another protein called CD154 (also known as CD40 ligand) to activate immune responses.

CD40 antigens are molecules that can stimulate an immune response when introduced into the body because they are recognized as foreign substances by the immune system. They may be used in vaccines or other immunotherapies to induce an immune response against specific targets, such as cancer cells or infectious agents.

CD40 antigens can also be found on some types of tumor cells, and activating CD40 with CD154 has been shown to enhance the anti-tumor immune response in preclinical models. Therefore, CD40 agonists are being investigated as potential cancer therapies.

In summary, CD40 antigens are proteins that can stimulate an immune response and are involved in activating immune cells. They have potential applications in vaccines, immunotherapies, and cancer treatments.

Autoantigens are substances that are typically found in an individual's own body, but can stimulate an immune response because they are recognized as foreign by the body's own immune system. In autoimmune diseases, the immune system mistakenly attacks and damages healthy tissues and organs because it recognizes some of their components as autoantigens. These autoantigens can be proteins, DNA, or other molecules that are normally present in the body but have become altered or exposed due to various factors such as infection, genetics, or environmental triggers. The immune system then produces antibodies and activates immune cells to attack these autoantigens, leading to tissue damage and inflammation.

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.

"Bordetella" is a genus of gram-negative, aerobic bacteria that are known to cause respiratory infections in humans and animals. The most well-known species within this genus is Bordetella pertussis, which is the primary causative agent of whooping cough (pertussis) in humans.

Whooping cough is a highly contagious respiratory infection that is characterized by severe coughing fits, followed by a high-pitched "whoop" sound upon inhalation. The bacteria attach to the cilia lining the respiratory tract and release toxins that damage the cilia and cause inflammation, leading to the characteristic symptoms of the disease.

Other species within the Bordetella genus include Bordetella parapertussis, which can also cause a milder form of whooping cough, and Bordetella bronchiseptica, which is associated with respiratory infections in animals but can occasionally infect humans as well.

Prevention of Bordetella infections typically involves vaccination, with vaccines available for both infants and adults to protect against B. pertussis and B. parapertussis. Good hygiene practices, such as covering the mouth and nose when coughing or sneezing, can also help prevent the spread of these bacteria.

Salmonella Enteritidis is a specific strain of the Salmonella bacterium that primarily infects the intestinal tract, leading to a type of foodborne illness known as salmonellosis. This organism can be found in a variety of animals and their feces, including poultry and cattle. It can contaminate various foods, particularly eggs, raw meat, and unpasteurized dairy products.

Infection with Salmonella Enteritidis typically occurs when an individual ingests contaminated food or water. The bacteria then multiply within the digestive system, causing symptoms such as diarrhea, abdominal cramps, fever, nausea, and vomiting. In some cases, particularly in individuals with weakened immune systems, Salmonella Enteritidis infection can lead to more severe complications, including bacteremia (bloodstream infection) and invasive diseases affecting other organs.

Preventing Salmonella Enteritidis infection involves proper food handling, cooking, and storage practices, as well as maintaining good hygiene and sanitation standards in both residential and commercial settings.

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.

Thy-1, also known as Thy-1 antigen or CD90, is a glycosylphosphatidylinositol (GPI)-anchored protein found on the surface of various cells in the body. It was first discovered as a cell surface antigen on thymocytes, hence the name Thy-1.

Thy-1 is a member of the immunoglobulin superfamily and is widely expressed in different tissues, including the brain, where it is found on the surface of neurons and glial cells. In the immune system, Thy-1 is expressed on the surface of T lymphocytes, natural killer (NK) cells, and some subsets of dendritic cells.

The function of Thy-1 is not fully understood, but it has been implicated in various biological processes, including cell adhesion, signal transduction, and regulation of immune responses. Thy-1 has also been shown to play a role in the development and maintenance of the nervous system, as well as in the pathogenesis of certain neurological disorders.

As an antigen, Thy-1 can be recognized by specific antibodies, which can be used in various research and clinical applications, such as immunohistochemistry, flow cytometry, and cell sorting.

'Proteus' doesn't have a specific medical definition itself, but it is related to a syndrome in medicine. Proteus syndrome is a rare genetic disorder characterized by the overgrowth of various tissues and organs in the body. The name "Proteus" comes from the Greek god Proteus, who could change his form at will, reflecting the diverse and ever-changing nature of this condition's symptoms.

People with Proteus syndrome experience asymmetric overgrowth of bones, skin, and other tissues, leading to abnormalities in body shape and function. The disorder can also affect blood vessels, causing benign tumors called hamartomas to develop. Additionally, individuals with Proteus syndrome are at an increased risk of developing certain types of cancer.

The genetic mutation responsible for Proteus syndrome is found in the AKT1 gene, which plays a crucial role in cell growth and division. This disorder is typically not inherited but instead arises spontaneously as a new mutation in the affected individual. Early diagnosis and management of Proteus syndrome can help improve patients' quality of life and reduce complications associated with the condition.

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.

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.

Escherichia coli (E. coli) infections refer to illnesses caused by the bacterium E. coli, which can cause a range of symptoms depending on the specific strain and site of infection. The majority of E. coli strains are harmless and live in the intestines of healthy humans and animals. However, some strains, particularly those that produce Shiga toxins, can cause severe illness.

E. coli infections can occur through various routes, including contaminated food or water, person-to-person contact, or direct contact with animals or their environments. Common symptoms of E. coli infections include diarrhea (often bloody), abdominal cramps, nausea, and vomiting. In severe cases, complications such as hemolytic uremic syndrome (HUS) can occur, which may lead to kidney failure and other long-term health problems.

Preventing E. coli infections involves practicing good hygiene, cooking meats thoroughly, avoiding cross-contamination of food during preparation, washing fruits and vegetables before eating, and avoiding unpasteurized dairy products and juices. Prompt medical attention is necessary if symptoms of an E. coli infection are suspected to prevent potential complications.

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.

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.

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.

The H-Y antigen is a complex of historically significant, male-specific proteins that are encoded by genes on the Y chromosome. These antigens were first discovered through studies of tissue rejection in animal models and were later found to be important in the field of transplantation immunology.

In a medical definition, the H-Y antigen refers to a group of antigens that are expressed on the cell surface of nucleated cells in males, including those found in tissues such as skin, muscle, and blood cells. They are recognized by the immune system as foreign when transplanted into females, leading to a rejection response.

The H-Y antigen has been the subject of extensive research due to its role in sex determination and differentiation, as well as its potential implications for autoimmune diseases and cancer biology. However, it's worth noting that the clinical relevance of the H-Y antigen is limited, and its study is primarily of academic interest.

Carbohydrates are a major nutrient class consisting of organic compounds that primarily contain carbon, hydrogen, and oxygen atoms. They are classified as saccharides, which include monosaccharides (simple sugars), disaccharides (double sugars), oligosaccharides (short-chain sugars), and polysaccharides (complex carbohydrates).

Monosaccharides, such as glucose, fructose, and galactose, are the simplest form of carbohydrates. They consist of a single sugar molecule that cannot be broken down further by hydrolysis. Disaccharides, like sucrose (table sugar), lactose (milk sugar), and maltose (malt sugar), are formed from two monosaccharide units joined together.

Oligosaccharides contain a small number of monosaccharide units, typically less than 20, while polysaccharides consist of long chains of hundreds to thousands of monosaccharide units. Polysaccharides can be further classified into starch (found in plants), glycogen (found in animals), and non-starchy polysaccharides like cellulose, chitin, and pectin.

Carbohydrates play a crucial role in providing energy to the body, with glucose being the primary source of energy for most cells. They also serve as structural components in plants (cellulose) and animals (chitin), participate in various metabolic processes, and contribute to the taste, texture, and preservation of foods.

'Brucella abortus' is a gram-negative, facultatively anaerobic coccobacillus that is the causative agent of brucellosis, also known as Bang's disease in cattle. It is a zoonotic disease, meaning it can be transmitted from animals to humans, and is typically acquired through contact with infected animal tissues or bodily fluids, consumption of contaminated food or drink, or inhalation of infectious aerosols.

In cattle, 'Brucella abortus' infection can cause abortion, stillbirths, and reduced fertility. In humans, it can cause a systemic illness characterized by fever, sweats, malaise, headache, and muscle and joint pain. If left untreated, brucellosis can lead to serious complications such as endocarditis, hepatomegaly, splenomegaly, and neurological symptoms.

Prevention measures include vaccination of cattle, pasteurization of dairy products, and implementation of strict hygiene practices in occupational settings where exposure to infected animals or their tissues is possible. Treatment typically involves a prolonged course of antibiotics, such as doxycycline and rifampin, and may require hospitalization in severe cases.

Burkholderia is a genus of gram-negative, rod-shaped bacteria that are widely distributed in the environment, including soil, water, and associated with plants. Some species of Burkholderia are opportunistic pathogens, meaning they can cause infection in individuals with weakened immune systems or underlying medical conditions.

One of the most well-known species of Burkholderia is B. cepacia, which can cause respiratory infections in people with cystic fibrosis and chronic granulomatous disease. Other notable species include B. pseudomallei, the causative agent of melioidosis, a potentially serious infection that primarily affects the respiratory system; and B. mallei, which causes glanders, a rare but severe disease that can affect humans and animals.

Burkholderia species are known for their resistance to many antibiotics, making them difficult to treat in some cases. Proper identification of the specific Burkholderia species involved in an infection is important for determining the most appropriate treatment approach.

Antigen-presenting cells (APCs) are a group of specialized cells in the immune system that play a critical role in initiating and regulating immune responses. They have the ability to engulf, process, and present antigens (molecules derived from pathogens or other foreign substances) on their surface in conjunction with major histocompatibility complex (MHC) molecules. This presentation of antigens allows APCs to activate T cells, which are crucial for adaptive immunity.

There are several types of APCs, including:

1. Dendritic cells (DCs): These are the most potent and professional APCs, found in various tissues throughout the body. DCs can capture antigens from their environment, process them, and migrate to lymphoid organs where they present antigens to T cells.
2. Macrophages: These large phagocytic cells are found in many tissues and play a role in both innate and adaptive immunity. They can engulf and digest pathogens, then present processed antigens on their MHC class II molecules to activate CD4+ T helper cells.
3. B cells: These are primarily responsible for humoral immune responses by producing antibodies against antigens. When activated, B cells can also function as APCs and present antigens on their MHC class II molecules to CD4+ T cells.

The interaction between APCs and T cells is critical for the development of an effective immune response against pathogens or other foreign substances. This process helps ensure that the immune system can recognize and eliminate threats while minimizing damage to healthy tissues.

Dendritic cells (DCs) are a type of immune cell that play a critical role in the body's defense against infection and cancer. They are named for their dendrite-like projections, which they use to interact with and sample their environment. DCs are responsible for processing antigens (foreign substances that trigger an immune response) and presenting them to T cells, a type of white blood cell that plays a central role in the immune system's response to infection and cancer.

DCs can be found throughout the body, including in the skin, mucous membranes, and lymphoid organs. They are able to recognize and respond to a wide variety of antigens, including those from bacteria, viruses, fungi, and parasites. Once they have processed an antigen, DCs migrate to the lymph nodes, where they present the antigen to T cells. This interaction activates the T cells, which then go on to mount a targeted immune response against the invading pathogen or cancerous cells.

DCs are a diverse group of cells that can be divided into several subsets based on their surface markers and function. Some DCs, such as Langerhans cells and dermal DCs, are found in the skin and mucous membranes, where they serve as sentinels for invading pathogens. Other DCs, such as plasmacytoid DCs and conventional DCs, are found in the lymphoid organs, where they play a role in activating T cells and initiating an immune response.

Overall, dendritic cells are essential for the proper functioning of the immune system, and dysregulation of these cells has been implicated in a variety of diseases, including autoimmune disorders and cancer.

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.

HLA-DQ antigens are a type of human leukocyte antigen (HLA) that are found on the surface of cells in our body. They are a part of the major histocompatibility complex (MHC) class II molecules, which play a crucial role in the immune system by presenting pieces of proteins from outside the cell to CD4+ T cells, also known as helper T cells. This presentation process is essential for initiating an appropriate immune response against potentially harmful pathogens such as bacteria and viruses.

HLA-DQ antigens are encoded by genes located on chromosome 6p21.3 in the HLA region. Each individual inherits a pair of HLA-DQ genes, one from each parent, which can result in various combinations of HLA-DQ alleles. These genetic variations contribute to the diversity of immune responses among different individuals.

HLA-DQ antigens consist of two noncovalently associated polypeptide chains: an alpha (DQA) chain and a beta (DQB) chain. There are several isotypes of HLA-DQ antigens, including DQ1, DQ2, DQ3, DQ4, DQ5, DQ6, DQ7, DQ8, and DQ9, which are determined by the specific combination of DQA and DQB alleles.

Certain HLA-DQ genotypes have been associated with an increased risk of developing certain autoimmune diseases, such as celiac disease (DQ2 and DQ8), type 1 diabetes (DQ2, DQ8), and rheumatoid arthritis (DQ4). Understanding the role of HLA-DQ antigens in these conditions can provide valuable insights into disease pathogenesis and potential therapeutic targets.

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.

CD86 is a type of protein found on the surface of certain immune cells called antigen-presenting cells (APCs), such as dendritic cells, macrophages, and B cells. These proteins are known as co-stimulatory molecules and play an important role in activating T cells, a type of white blood cell that is crucial for adaptive immunity.

When APCs encounter a pathogen or foreign substance, they engulf it, break it down into smaller peptides, and display these peptides on their surface in conjunction with another protein called the major histocompatibility complex (MHC) class II molecule. This presentation of antigenic peptides to T cells is not sufficient to activate them fully. Instead, APCs must also provide a co-stimulatory signal through interactions between co-stimulatory molecules like CD86 and receptors on the surface of T cells, such as CD28.

CD86 binds to its receptor CD28 on T cells, providing a critical second signal that promotes T cell activation, proliferation, and differentiation into effector cells. This interaction is essential for the development of an effective immune response against pathogens or foreign substances. In addition to its role in activating T cells, CD86 also helps regulate immune tolerance by contributing to the suppression of self-reactive T cells that could otherwise attack the body's own tissues and cause autoimmune diseases.

Overall, CD86 is an important player in the regulation of the immune response, helping to ensure that T cells are activated appropriately in response to pathogens or foreign substances while also contributing to the maintenance of self-tolerance.

Ovalbumin is the major protein found in egg white, making up about 54-60% of its total protein content. It is a glycoprotein with a molecular weight of around 45 kDa and has both hydrophilic and hydrophobic regions. Ovalbumin is a single polypeptide chain consisting of 385 amino acids, including four disulfide bridges that contribute to its structure.

Ovalbumin is often used in research as a model antigen for studying immune responses and allergies. In its native form, ovalbumin is not allergenic; however, when it is denatured or degraded into smaller peptides through cooking or digestion, it can become an allergen for some individuals.

In addition to being a food allergen, ovalbumin has been used in various medical and research applications, such as vaccine development, immunological studies, and protein structure-function analysis.

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.

"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.

Simian Virus 40 (SV40) is a polyomavirus that is found in both monkeys and humans. It is a DNA virus that has been extensively studied in laboratory settings due to its ability to transform cells and cause tumors in animals. In fact, SV40 was discovered as a contaminant of poliovirus vaccines that were prepared using rhesus monkey kidney cells in the 1950s and 1960s.

SV40 is not typically associated with human disease, but there has been some concern that exposure to the virus through contaminated vaccines or other means could increase the risk of certain types of cancer, such as mesothelioma and brain tumors. However, most studies have failed to find a consistent link between SV40 infection and cancer in humans.

The medical community generally agrees that SV40 is not a significant public health threat, but researchers continue to study the virus to better understand its biology and potential impact on human health.

Cytotoxic T-lymphocytes, also known as CD8+ T cells, are a type of white blood cell that plays a central role in the cell-mediated immune system. They are responsible for identifying and destroying virus-infected cells and cancer cells. When a cytotoxic T-lymphocyte recognizes a specific antigen presented on the surface of an infected or malignant cell, it becomes activated and releases toxic substances such as perforins and granzymes, which can create pores in the target cell's membrane and induce apoptosis (programmed cell death). This process helps to eliminate the infected or malignant cells and prevent the spread of infection or cancer.

Salmonella phages are viruses that infect and replicate within bacteria of the genus Salmonella. These phages, also known as bacteriophages or simply phages, are composed of a protein capsid that encases the genetic material, which can be either DNA or RNA. They specifically target Salmonella bacteria, using the bacteria's resources to replicate and produce new phage particles. This process often leads to the lysis (breaking open) of the bacterial cell, resulting in the release of newly formed phages.

Salmonella phages have been studied as potential alternatives to antibiotics for controlling Salmonella infections, particularly in food production settings. They offer the advantage of being highly specific to their target bacteria, reducing the risk of disrupting beneficial microbiota. However, further research is needed to fully understand their safety and efficacy before they can be widely used as therapeutic or prophylactic agents.

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.

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.

1. Receptors: In the context of physiology and medicine, receptors are specialized proteins found on the surface of cells or inside cells that detect and respond to specific molecules, known as ligands. Receptors play a crucial role in signal transduction, enabling cells to communicate with each other and respond to changes in their environment.
2. Antigen: An antigen is any substance (usually a protein) that can be recognized by the immune system and stimulate an immune response. Antigens can be foreign substances such as bacteria, viruses, or pollen, or they can be components of our own cells, such as tumor antigens in cancer cells. Antigens are typically bound and presented to the immune system by specialized cells called antigen-presenting cells (APCs).
3. T-Cell: T-cells, also known as T lymphocytes, are a type of white blood cell that plays a central role in cell-mediated immunity. T-cells are produced in the bone marrow and mature in the thymus gland. There are two main types of T-cells: CD4+ helper T-cells and CD8+ cytotoxic T-cells. Helper T-cells assist other immune cells, such as B-cells and macrophages, in mounting an immune response, while cytotoxic T-cells directly kill infected or cancerous cells.
4. Alpha-Beta: Alpha-beta is a type of T-cell receptor (TCR) that is found on the surface of most mature T-cells. The alpha-beta TCR is composed of two polypeptide chains, an alpha chain and a beta chain, that are held together by disulfide bonds. The alpha-beta TCR recognizes and binds to specific antigens presented in the context of major histocompatibility complex (MHC) molecules on the surface of APCs. This interaction is critical for initiating an immune response against infected or cancerous cells.

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.

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.

Magnetic Resonance Spectroscopy (MRS) is a non-invasive diagnostic technique that provides information about the biochemical composition of tissues, including their metabolic state. It is often used in conjunction with Magnetic Resonance Imaging (MRI) to analyze various metabolites within body tissues, such as the brain, heart, liver, and muscles.

During MRS, a strong magnetic field, radio waves, and a computer are used to produce detailed images and data about the concentration of specific metabolites in the targeted tissue or organ. This technique can help detect abnormalities related to energy metabolism, neurotransmitter levels, pH balance, and other biochemical processes, which can be useful for diagnosing and monitoring various medical conditions, including cancer, neurological disorders, and metabolic diseases.

There are different types of MRS, such as Proton (^1^H) MRS, Phosphorus-31 (^31^P) MRS, and Carbon-13 (^13^C) MRS, each focusing on specific elements or metabolites within the body. The choice of MRS technique depends on the clinical question being addressed and the type of information needed for diagnosis or monitoring purposes.

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.

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.

CTLA-4 (Cytotoxic T-Lymphocyte Associated Protein 4) antigen is a type of protein found on the surface of activated T cells, which are a type of white blood cell in the immune system. CTLA-4 plays an important role in regulating the immune response by functioning as a negative regulator of T cell activation.

CTLA-4 binds to CD80 and CD86 molecules on the surface of antigen-presenting cells, which are cells that display foreign antigens to T cells and activate them. By binding to these molecules, CTLA-4 inhibits T cell activation and helps prevent an overactive immune response.

CTLA-4 is a target for cancer immunotherapy because blocking its function can enhance the anti-tumor immune response. Certain drugs called checkpoint inhibitors work by blocking CTLA-4, allowing T cells to remain active and attack tumor cells more effectively.

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.

Thymine nucleotides are biochemical components that play a crucial role in the structure and function of DNA (deoxyribonucleic acid), which is the genetic material present in living organisms. A thymine nucleotide consists of three parts: a sugar molecule called deoxyribose, a phosphate group, and a nitrogenous base called thymine.

Thymine is one of the four nucleobases in DNA, along with adenine, guanine, and cytosine. It specifically pairs with adenine through hydrogen bonding, forming a base pair that is essential for maintaining the structure and stability of the double helix. Thymine nucleotides are linked together by phosphodiester bonds between the sugar molecules of adjacent nucleotides, creating a long, linear polymer known as a DNA strand.

In summary, thymine nucleotides are building blocks of DNA that consist of deoxyribose, a phosphate group, and the nitrogenous base thymine, which pairs with adenine in the double helix structure.

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.

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.

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.

Interferon-gamma (IFN-γ) is a soluble cytokine that is primarily produced by the activation of natural killer (NK) cells and T lymphocytes, especially CD4+ Th1 cells and CD8+ cytotoxic T cells. It plays a crucial role in the regulation of the immune response against viral and intracellular bacterial infections, as well as tumor cells. IFN-γ has several functions, including activating macrophages to enhance their microbicidal activity, increasing the presentation of major histocompatibility complex (MHC) class I and II molecules on antigen-presenting cells, stimulating the proliferation and differentiation of T cells and NK cells, and inducing the production of other cytokines and chemokines. Additionally, IFN-γ has direct antiproliferative effects on certain types of tumor cells and can enhance the cytotoxic activity of immune cells against infected or malignant cells.

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.

Carbon-oxygen ligases are a category of enzymes that catalyze the joining of a carbon atom and an oxygen atom, typically through the formation of a carbon-oxygen bond. These enzymes play important roles in various metabolic processes, such as the synthesis of carbohydrates, lignin, and other organic compounds.

In biochemistry, ligases are enzymes that catalyze the formation of covalent bonds between two molecules, often requiring energy in the form of ATP or another high-energy molecule to drive the reaction. Carbon-oxygen ligases specifically facilitate the formation of carbon-oxygen bonds, which can be found in a wide range of organic compounds, including alcohols, aldehydes, ketones, carboxylic acids, and esters.

Examples of carbon-oxygen ligases include:

1. Alcohol dehydrogenase (ADH): This enzyme catalyzes the interconversion between alcohols and aldehydes or ketones by transferring a hydride ion from the alcohol to a cofactor, such as NAD+ or NADP+, resulting in the formation of a carbon-oxygen bond.
2. Aldolase: This enzyme catalyzes the reversible reaction between an aldehyde and a ketone to form a new carbon-carbon bond and a carbon-oxygen bond, creating a new molecule called an aldol.
3. Carboxylases: These enzymes facilitate the addition of a carboxyl group (-COOH) to various substrates, resulting in the formation of a carbon-oxygen bond between the carboxyl group and the substrate. Examples include acetyl-CoA carboxylase, which catalyzes the formation of malonyl-CoA, an essential intermediate in fatty acid synthesis.
4. Transketolases: These enzymes are involved in the pentose phosphate pathway and facilitate the transfer of a two-carbon ketol group between sugars, resulting in the formation of new carbon-oxygen bonds.
5. Esterases: These enzymes catalyze the hydrolysis or synthesis of esters by breaking or forming carbon-oxygen bonds between an alcohol and an acid.
6. Peroxidases: These enzymes use a reactive oxygen species, such as hydrogen peroxide (H2O2), to oxidize various substrates, resulting in the formation of new carbon-oxygen bonds.
7. Dehydrogenases: These enzymes catalyze the transfer of electrons from a donor molecule to an acceptor molecule, often involving the formation or breaking of carbon-oxygen bonds. Examples include lactate dehydrogenase and alcohol dehydrogenase.
8. Oxidoreductases: This broad class of enzymes catalyzes oxidation-reduction reactions, which can involve the formation or breaking of carbon-oxygen bonds.

Fucose is a type of sugar molecule that is often found in complex carbohydrates known as glycans, which are attached to many proteins and lipids in the body. It is a hexose sugar, meaning it contains six carbon atoms, and is a type of L-sugar, which means that it rotates plane-polarized light in a counterclockwise direction.

Fucose is often found at the ends of glycan chains and plays important roles in various biological processes, including cell recognition, signaling, and interaction. It is also a component of some blood group antigens and is involved in the development and function of the immune system. Abnormalities in fucosylation (the addition of fucose to glycans) have been implicated in various diseases, including cancer, inflammation, and neurological disorders.

The ABO blood-group system is a classification system used in blood transfusion medicine to determine the compatibility of donated blood with a recipient's blood. It is based on the presence or absence of two antigens, A and B, on the surface of red blood cells (RBCs), as well as the corresponding antibodies present in the plasma.

There are four main blood types in the ABO system:

1. Type A: These individuals have A antigens on their RBCs and anti-B antibodies in their plasma.
2. Type B: They have B antigens on their RBCs and anti-A antibodies in their plasma.
3. Type AB: They have both A and B antigens on their RBCs but no natural antibodies against either A or B antigens.
4. Type O: They do not have any A or B antigens on their RBCs, but they have both anti-A and anti-B antibodies in their plasma.

Transfusing blood from a donor with incompatible ABO antigens can lead to an immune response, causing the destruction of donated RBCs and potentially life-threatening complications such as acute hemolytic transfusion reaction. Therefore, it is crucial to match the ABO blood type between donors and recipients before performing a blood transfusion.

CD79 is a type of protein that is found on the surface of B cells, which are a type of white blood cell that plays a key role in the immune system. CD79 combines with another protein called CD19 to form a complex that helps to activate B cells and initiate an immune response when the body encounters an antigen.

An antigen is any substance that can stimulate an immune response, particularly the production of antibodies. Antigens can be proteins, polysaccharides, or other molecules found on the surface of viruses, bacteria, or other foreign substances. When a B cell encounters an antigen, it engulfs and processes the antigen, then displays a portion of it on its surface along with CD79 and CD19. This helps to activate the B cell and stimulate it to divide and differentiate into plasma cells, which produce and secrete large amounts of antibodies that recognize and bind to the antigen.

CD79 is an important marker for identifying and studying B cells, and it has been implicated in various B-cell malignancies such as chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL).

Polymyxin B is an antibiotic derived from the bacterium Paenibacillus polymyxa. It belongs to the class of polypeptide antibiotics and has a cyclic structure with a hydrophobic and a hydrophilic region, which allows it to interact with and disrupt the bacterial cell membrane. Polymyxin B is primarily active against gram-negative bacteria, including many multidrug-resistant strains. It is used clinically to treat serious infections caused by these organisms, such as sepsis, pneumonia, and urinary tract infections. However, its use is limited due to potential nephrotoxicity and neurotoxicity.

Antibodies, protozoan, refer to the immune system's response to an infection caused by a protozoan organism. Protozoa are single-celled microorganisms that can cause various diseases in humans, such as malaria, giardiasis, and toxoplasmosis.

When the body is infected with a protozoan, the immune system responds by producing specific proteins called antibodies. Antibodies are produced by a type of white blood cell called a B-cell, and they recognize and bind to specific antigens on the surface of the protozoan organism.

There are five main types of antibodies: IgA, IgD, IgE, IgG, and IgM. Each type of antibody has a different role in the immune response. For example, IgG is the most common type of antibody and provides long-term immunity to previously encountered pathogens. IgM is the first antibody produced in response to an infection and is important for activating the complement system, which helps to destroy the protozoan organism.

Overall, the production of antibodies against protozoan organisms is a critical part of the immune response and helps to protect the body from further infection.

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.

CA 19-9 antigen, also known as carbohydrate antigen 19-9, is a tumor marker that is commonly found in the blood. It is a type of sialylated Lewis blood group antigen, which is a complex carbohydrate molecule found on the surface of many cells in the body.

CA 19-9 antigen is often elevated in people with certain types of cancer, particularly pancreatic cancer, bile duct cancer, and colon cancer. However, it can also be elevated in noncancerous conditions such as pancreatitis, liver cirrhosis, and cholestasis. Therefore, CA 19-9 antigen is not a specific or sensitive marker for cancer, and its use as a screening test for cancer is not recommended.

Instead, CA 19-9 antigen is often used as a tumor marker to monitor the response to treatment in people with known cancers, particularly pancreatic cancer. A decrease in CA 19-9 antigen levels may indicate that the cancer is responding to treatment, while an increase may suggest that the cancer is growing or has recurred. However, it is important to note that CA 19-9 antigen levels can also be affected by other factors, such as the size and location of the tumor, the presence of obstructive jaundice, and the patient's overall health status. Therefore, CA 19-9 antigen should always be interpreted in conjunction with other clinical and diagnostic findings.

... (LSA) are a set of peptides from Plasmodium falciparum that are recognized by the body's immune system. ...
... are antigens found on all T cells. They include CD2, CD3, CD5 and CD7. Mario Roederer (October 2004). Cytometry ... v t e (All stub articles, Biochemistry stubs, Antigen presenting cells). ...
All that remains are the Csa and Csb antigens. Csa is a very high frequency (>98%) antigen and Csb is not uncommon (~34%). The ... In addition to the defined human blood group systems, there are erythrocyte antigens which do not meet the definition of a ... Reagents to test for these antigens are difficult to find and many cannot be purchased commercially. These three groups are ... antigens with shared characteristics but do not meet the International Society of Blood Transfusion (ISBT) definition of a ...
T-independent antigen - Antigens that stimulate B cells directly. Immunodominant antigens - Antigens that dominate (over all ... A native antigen is an antigen that is not yet processed by an APC to smaller parts. T cells cannot bind native antigens, but ... Antigens can be classified according to their source. Exogenous antigens are antigens that have entered the body from the ... Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by ...
... also known as oncofetal antigen protein). Oncofetal antigens are promising targets for vaccination against several types of ... Oncofetal antigens are proteins which are typically present only during fetal development but are found in adults with certain ... One example of an oncofetal antigen is alpha-fetoprotein, which is produced by hepatocellular carcinoma and some germ cell ... Another example is carcinoembryonic antigen, which is elevated in people with colon cancer and other tumors. Other oncofetal ...
The Dharmendra antigen is a test widely used in India. The antigen is a suspension of de-fatted leprosy bacilli which has been ... This antigen was first reported by Dharmendra in 1941-42 and later standardized in 1979 by Sangupta et al. Dharmendra's ... Mohanty J, Mohanty H C. Lepromin response with dharmendra antigen in patients with leprosy. Indian J Dermatol Venereol Leprol [ ... serial online] 1997 [cited 2016 Jun 20];63:385-7. Available from: http://www.ijdvl.com/text.asp?1997/63/6/385/4627 (Antigen ...
Example: Forssman antigen, cross reacting microbial antigen so antibodies to these antigens produced by one species cross react ... Heterophile antigens are antigens of similar nature, if not identical, that are present in different tissues in different ... Usually different species have different antigen sets, but the hetereophile antigen is shared by different species. Other ... v t e v t e (Articles with short description, Short description matches Wikidata, Antibodies, Immunology, Antigens, All stub ...
Carcinoembryonic+Antigen at the U.S. National Library of Medicine Medical Subject Headings (MeSH) CEA at Lab Tests Online CEA: ... Carcinoembryonic antigen (CEA) describes a set of highly-related glycoproteins involved in cell adhesion. CEA is normally ... Asad-Ur-Rahman F, Saif MW (June 2016). "Elevated Level of Serum Carcinoembryonic Antigen (CEA) and Search for a Malignancy: A ... Ballesta AM, Molina R, Filella X, Jo J, Giménez N (1995). "Carcinoembryonic antigen in staging and follow-up of patients with ...
... the Thomsen-Friedenreich antigen (Gal(b1-3)GalNAc). The sialyl Tn antigen (STn antigen) is formed by elongation with sialic ... Tn antigen is expressed in most carcinomas. Addition of an additional galactose monosaccharide creates a disaccharide antigen: ... Tn antigen refers to the monosaccharide structure N-acetylgalactosamine (GalNAc) linked to serine or threonine by a glycosidic ... bond, considered as an antigen. The initials stand for Thomsen-nouveau. ...
The Forssman antigen is a glycolipid heterophil protein and a type of heterogenetic antigen found in certain animals like dogs ... The Forssman antigen is distinct from the Paul-Bunnell antigen, antibodies to which are diagnostic of glandular fever ( ... Both antigens are present on the red blood cells of horse and sheep but guinea pig kidney cells have only the Forssman antigen ... Forssman Antigen -- Medical Definition (Articles lacking in-text citations from June 2013, All articles lacking in-text ...
CD molecules are leucocyte antigens on cell surfaces. CD antigens nomenclature is updated at Protein Reviews On The Web (https ... CD36 antigen is a transmembrane, highly glycosylated, glycoprotein expressed by monocytes, macrophages, platelets, ...
CDw17+antigen at the U.S. National Library of Medicine Medical Subject Headings (MeSH) v t e (Articles needing additional ... CDw17 antigen is a lactosylceramide, a class of glycosphingolipids found in microdomains on the plasma layers of numerous cells ...
... is an approach to reducing or eliminating these chemical modifications. The two primary methods of antigen ... "Antigen Retrieval Methods". R&D Systems. Retrieved 20 March 2019. "Antigen Retrieval Methods, Techniques, Protocols". www. ... Ino, Hidetoshi (2003). "Antigen retrieval by heating en bloc for pre-fixed frozen material". The Journal of Histochemistry and ... Brown, D (1996). "Antigen retrieval in cryostat tissue sections and cultured cells by treatment with sodium dodecyl sulfate ( ...
... can refer to one of various types of antigens having diverse biological functions. H antigen is located on the 19th ... minor H antigens "present polymorphic self peptides to T cells". Includes, e.g. the H-Y antigen a bacterial flagellar antigen ... H antigen is a precursor to each of the ABO blood group antigens, apparently present in all people except those with the Bombay ... "antigen". The Free Dictionary. Retrieved 16 December 2013. v t e (Articles with short description, Short description matches ...
... mutant protein antigens, oncogenic viral antigens, cancer-testis antigens and vascular or stromal specific antigens. Tissue ... and some viral antigens are also cancer antigens. Cancer-testis antigens are antigens expressed primarily in the germ cells of ... Certain tumor antigens are thus used as tumor markers. More importantly, tumor antigens can be used in cancer therapy as tumor ... Oncofetal antigens are another important class of tumor antigens. Examples are alphafetoprotein (AFP) and carcinoembryonic ...
Because T cells recognize only fragmented antigens displayed on cell surfaces, antigen processing must occur before the antigen ... They have to be activated by the pMHC-I complexes of antigen-presenting cells (APCs). Here, antigen can be presented directly ( ... June 2015). "Peptide-MHC-I from Endogenous Antigen Outnumber Those from Exogenous Antigen, Irrespective of APC Phenotype or ... with the peptide antigen. Peptide-MHC-II complexes (pMHC-II) are transported to the plasma membrane and the processed antigen ...
A somatic antigen is an antigen located in the cell wall of a gram-positive or gram-negative bacterium. Lipopolysaccharide " ... "somatic antigen". TheFreeDictionary.com. Retrieved 7 May 2019. v t e (Articles with short description, Short description ...
T-independent antigen - Antigens that stimulate B cells directly. Lymphocytes are one of the five kinds of white blood cells or ... The bound antigen molecules are engulfed into the B cell by receptor-mediated endocytosis. The antigen is digested into peptide ... Both MHC class I and II are required to bind antigens before they are stably expressed on a cell surface. MHC I antigen ... T-dependent antigen - Antigens that require the assistance of T cells to induce the formation of specific antibodies. ...
In some patients, the majority of the tumor-specific T cells recognize mutated antigens. The contribution of these antigens to ... The carcinoma cells still harbour the viral genes and antigens. As expected T cell responses against antigens encoded by genes ... Cancer therapy targeted at tumor antigens can involve the direct use of these antigens in vaccines, but also the adoptive ... It is now proven that tumor-specific antigens exist and that patients mount spontaneous T cell responses against such antigens ...
This is a list of antigens in the skin that may become targets of circulating auto-antibodies leading to the various types of ... List of target antigens in pemphigoid List of conditions caused by problems with junctional proteins List of immunofluorescence ...
This is a list of antigens in the skin that may become targets of circulating auto-antibodies leading to the various types of ... List of target antigens in pemphigus List of immunofluorescence findings for autoimmune bullous conditions List of cutaneous ...
The XG antigen is a red blood cell surface antigen discovered in 1962. by researchers at the MRC Blood Group Unit. The PBDX ... Blood antigen systems, All stub articles, Cell biology stubs, Transfusion medicine). ... gene that encodes the antigen is located on the short arm of the X chromosome. Since males normally have one X chromosome they ...
The mammalian members of the MAGE (melanoma-associated antigen) gene family were originally described as completely silent in ...
... is a marker of abnormal self, which can be recognized upon infected (in particular, virus-infected) and ... Similarly γδ T cells can recognize induced-self antigens expressed on cells under stress conditions. Probably the most studied ... Born, Willi K; M Kemal Aydintug; Rebecca L O'Brien (January 2013). "Diversity of γδ T-cell antigens". Cellular & Molecular ... Other receptors able to bind induced-self antigens are NKG2C, NKG2E, NKG2F (CD94) or some NCRs (e.g. NKp 46 ). Practical use of ...
The antigens Aua and Aub, known as the Auberger antigens, were once thought to make up a separate blood group but were later ... The Lutheran antigen systems is a classification of human blood based on the presence of substances called Lutheran antigens on ... There are 19 known Lutheran antigens. All of these antigens arise from variations in a gene called BCAM (basal cell adhesion ... ISBN 978-0-7817-6507-7. v t e (Articles with short description, Short description matches Wikidata, Blood antigen systems, ...
Online Mendelian Inheritance in Man (OMIM): 112100 - OMIM page on Yt antigen Yt at BGMUT Blood Group Antigen Gene Mutation ... The Yt antigen system (also known as Cartwright) is present on the membrane of red blood cells and helps determine a person's ... The antigens are found on the protein acetylcholinesterase, an enzyme which helps break down acetylcholine. The Yt system ... Database at NCBI, NIH v t e (Articles with short description, Short description matches Wikidata, Blood antigen systems, Genes ...
Firstly, the antigen and antibody rapidly form antigen-antibody complexes within few seconds and this is followed by a slower ... It acts on antigen-antibody reaction in which the antibodies cross-link particulate antigens resulting in the visible clumping ... Antigen-antibody interaction, or antigen-antibody reaction, is a specific chemical interaction between antibodies produced by B ... In the blood, the antigens are specifically and with high affinity bound by antibodies to form an antigen-antibody complex. The ...
... is a male tissue specific antigen. Originally thought to trigger the formation of testes (via loci, an autosomal ... One theory to explain this involves H-Y antigens, which suggests that a maternal immune reaction to these antigens has, to an ... which would be expected since H-Y antigen is male tissue specific, the 'probable involvement of H-Y antigen in the development ... There are several antigens which qualify as H-Y as defined by rejection of male skin grafts in female hosts or detected by ...
The I antigen was first described in 1956 and the i antigen was discovered in 1960. I and i were the first discovered antigens ... when I antigen starts to be expressed instead. Like ABH antigens, which make up the ABO blood group, I and i antigens are not ... The Ii antigen system is a human blood group system based upon a gene on chromosome 6 and consisting of the I antigen and the i ... The I antigen is normally present on the cell membrane of red blood cells in all adults, while the i antigen is present in ...
An antigen-presenting cell (APC) or accessory cell is a cell that displays antigen bound by major histocompatibility complex ( ... Antigen: protease degradation on YouTube - PMAP animation Antigen-Presenting+Cells at the U.S. National Library of Medicine ... Professional antigen-presenting cells, including macrophages, B cells and dendritic cells, present foreign antigens to helper T ... The T cell recognizes and interacts with the antigen-class II MHC molecule complex on the membrane of the antigen-presenting ...
T-independent antigen - Antigens that stimulate B cells directly. Immunodominant antigens - Antigens that dominate (over all ... A native antigen is an antigen that is not yet processed by an APC to smaller parts. T cells cannot bind native antigens, but ... Antigens can be classified according to their source. Exogenous antigens are antigens that have entered the body from the ... Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by ...
The rotavirus antigen test detects rotavirus in the feces. This is the most common cause of infectious diarrhea in children. ... The rotavirus antigen test detects rotavirus in the feces. This is the most common cause of infectious diarrhea in children. ... The rotavirus antigen test detects rotavirus in the feces. This is the most common cause of infectious diarrhea in children. ...
The Jka antigen occurs in more than 90 percent of blacks, 75 percent of whites, and 70 percent of Asians. The Jkb antigen is ... three known antigens, designated Jka, Jkb, and Jk3, all of which are encoded by a gene known as SLC14A1 (solute carrier family ... The Jka antigen occurs in more than 90 percent of blacks, 75 percent of whites, and 70 percent of Asians. The Jkb antigen is ... three known antigens, designated Jka, Jkb, and Jk3, all of which are encoded by a gene known as SLC14A1 (solute carrier family ...
Nationwide Shortage of Tuberculin Skin Test Antigens. CDC is expecting a 3-10 month nationwide shortage of Aplisol, a product ... Two FDA-approved PPD tuberculin antigen products are available in the United States for use in performing TSTs: Tubersol ( ... 06/21/2019: Lab Advisory: Nationwide Shortage of Tuberculin Skin Test Antigens. ... of Par Pharmaceuticals, and one of two purified-protein derivative (PPD) tuberculin antigens licensed by the Food and Drug ...
Although PEComa family tumors commonly demonstrate a perivascular growth pattern, pericyte antigen expression has not yet been ... Pericyte antigens in angiomyolipoma and PEComa family tumors Med Oncol. 2015 Aug;32(8):210. doi: 10.1007/s12032-015-0659-y. ... In summary, pericyte antigen expression is variable among PEComa family tumors and largely varies by tumor morphology. ... Here, we describe the presence of pericyte antigens across a diverse group of PEComa family tumors (n = 19 specimens). Results ...
I need some antigens that raise T cell immunity in mice that are H-2k but not H-2b, and in H-2b but not H-2k. If you know of ... Need H-2 restricted Antigens. Tom Thatcher ttha at uhura.cc.rochester.edu Thu Apr 18 12:05:02 EST 1996 *Previous message: ... such antigens or useful references, please point them out. Some caveats: I know about the WEHI database of MHC binding peptides ...
DNA sequence variation within human leukocyte antigen (HLA) genes mediate susceptibility to a wide range of human diseases. The ... Imputing amino acid polymorphisms in human leukocyte antigens PLoS One. 2013 Jun 6;8(6):e64683. doi: 10.1371/journal.pone. ... DNA sequence variation within human leukocyte antigen (HLA) genes mediate susceptibility to a wide range of human diseases. The ...
rhesus C/E antigens. rhesus blood group antigen, RhC antigen. rhesus blood group little e antigen. silenced Rh blood group CcEe ... Rh blood group C antigen. Rh blood group CE antigen. Rh blood group CcEe antigen. Rh blood group CcEe antigens RHCE_916G. Rh ... Rhesus blood group CcEe antigen. Rhesus blood group E antigen. Rhesus blood group Rhce antigen. Rhesus blood group antigen CE. ... Rh blood group antigen Evans. Rh blood group protein. Rh polypeptide I. RhCE blood group antigen. RhCE blood group antigens. ...
Total prostate specific antigen (ng/mL). English Text: Total prostate specific antigen (ng/mL). Target: Males only 40 YEARS - ... Free prostate specific antigen (ng/mL). English Text: Free prostate specific antigen (ng/mL). Target: Males only 40 YEARS - 150 ... Complex prostate specific antigen(ng/mL). English Text: Complexed prostate specific antigen (ng/mL). Target: Males only 40 ... LBDP3 - Prostate specific antigen ratio (%). Variable Name: LBDP3. SAS Label: Prostate specific antigen ratio (%). English Text ...
... pylori antigen stool test if a child has symptoms of a peptic ulcer, such as indigestion, belly pain, a full or bloated feeling ... In this test, a stool sample is tested to check for H. pylori (pie-LOR-eye) antigens. Antigens (ANN-tih-jins) are substances ... A blue color indicates the presence of H. pylori antigens.. What if I Have Questions?. If you have questions about the H. ... An H. Pylori antigen test also can see if antibiotic treatment for an H. Pylori infection has worked. ...
The HIV-1 antigen is an earlier tip-off to HIV-1 infection than HIV-1 antibodies by themselves. The new test can tell the ... Cite this: FDA OKs First Rapid Test for HIV-1/2 Antibodies, HIV-1 Antigen - Medscape - Aug 08, 2013. ... FDA OKs First Rapid Test for HIV-1/2 Antibodies, HIV-1 Antigen. ... can detect HIV antibodies and the HIV-1 p24 antigen in human ... today approved the first rapid diagnostic test to spot antibodies to both HIV types 1 and 2 as well as the HIV-1 p24 antigen. ...
Cultures and Bacterial Antigen Testing. Obtaining cultures before instituting antibiotics may be helpful if the diagnosis is ... The Binax NOW S pneumoniae antigen test, if done on CSF, has a 99% to 100% sensitivity and specificity and can even be positive ... This is a latex agglutination technique that can detect the antigens of H influenzae type B (Hib), S pneumoniae, N meningitidis ... Others studies, however, have shown that the CSF bacterial antigen assay may not be better than the Gram stain. Although it is ...
Posted in Medical Hacks, TeardownTagged antigen, antigen test, coronavirus, COVID, Covid-19. ... The device is an antigen test and, internally, works like the home tests that show the results using lines similar to a ... If you want to read more about antigen tests, we covered that. We also talked about PCR testing. ...
Home Topics Cancer Serametrix Allies with Ludwig Institute to Exploit Tumor Antigens as Biomarkers ... The institutes flagship antigen, NY-ESO-1, has been licensed to Serametrix as part of this agreement. It has reportedly ... Antibodies (Immune signalling)AntigensBiomarkersCancersDiagnosisImmune componentImmune signallingImmunologyMedicine, Diagnosis ...
The strength of interaction between antibody and antigen at single antigenic sites can be described by the affinity of the ... Nature of Antigen-Antibody Bonds. Factors Affecting Antigen-Antibody Reactions. Antibody-Antigen Interaction Kinetics. The ... Factors Affecting Antigen-Antibody Reactions. The antigen-antibody reaction can be influenced by several factors. Some of the ... Nature of Antigen-Antibody Bonds. The combining site of an antibody is located in the F(ab) portion of the antibody molecule ...
Antigen tests diagnose viral infections, monitor certain illnesses or look for stem cell compatibility. ... An antigen is anything recognized by your immune system. ... What is an antigen?. An antigen is any kind of marker - like a ... These include exogenous antigens, endogenous antigens, autoantigens and tumor antigens.. Exogenous antigens. Exogenous antigens ... Antigen. An antigen is a marker that tells your immune system whether something in your body is harmful or not. Antigens are ...
2023 Rady Childrens Hospital-San Diego. ...
Advances the Elimination of Antigens Present in Alzheimers Disease & PTSD/Chronic Traumatic Encephalopathy. ...
Helicobacter pylori antigen testing is FDA approved for use as a noninvasive diagnostic test of H pylori infection and as a ... H pylori stool antigen testing is newer than its noninvasive constituents, serology and the urea breath test. Stool antigen ... encoded search term (Helicobacter Pylori Antigen Test) and Helicobacter Pylori Antigen Test What to Read Next on Medscape ... H pylori antigen testing is FDA approved for use as a noninvasive diagnostic test of H pylori infection and as a test to ...
lymphocyte antigen 6 complex locus protein G5c. Names. lymphocyte antigen 6 complex, locus G5C. lymphocyte antigen-6 G5C. ... LY6G5C lymphocyte antigen 6 family member G5C [Homo sapiens] LY6G5C lymphocyte antigen 6 family member G5C [Homo sapiens]. Gene ... lymphocyte antigen 6 family member G5Cprovided by HGNC. Primary source. HGNC:HGNC:13932 See related. Ensembl:ENSG00000204428 ... LY6G5C lymphocyte antigen 6 family member G5C [ Homo sapiens (human) ] Gene ID: 80741, updated on 23-Nov-2023 ...
On their surface, these special white blood cells carry a receptor that recognizes antigens. ... A comparison of the antigen-bound structure captured using cryo-electron microscopy with that of a receptor without antigen ... Tags: Antigen, B Cell, Bacteria, Biochemistry, Blood, Cancer, Cell, Cell Membrane, Electron, Electron Microscopy, Fish, Immune ... Researchers visualize antigen-bound T-cell receptor at atomic resolution. *Download PDF Copy ...
In non-key areas, those who take antigen self-tests and get a positive result are required to further take nucleic acid tests ... Shanghai residents continue to take antigen self-tests on Sunday since the city started on Saturday to try out the practice of ... Tao suggested that the results of the antigen self-test should be uploaded to the nations unified system like its done with ... Meanwhile, some mini apps have been developed by some tech companies for users to upload and record their antigen self-test ...
PCR tests and antigen tests. A professor in molecular medicine explains the science between the two. ... PCR tests and antigen tests are the two main ways to detect SARS-CoV-2.. Image: REUTERS/Heo Ran/File Photo ... Rapid antigen tests - like the two seen here showing negative results - are much faster and easier to perform but are less ... Whats the difference between a PCR and antigen COVID-19 test? A molecular biologist explains. .chakra .wef-vfu1qj{margin-top: ...
Intestinal reovirus infection can trigger T helper 1 (T1) immunity to dietary antigen, raising the question of whether other ... at sites where T cell responses to dietary antigens take place interferes with the development of tolerance to an oral antigen ... induces T1 immunity to dietary antigen. This property of CW3 is dependent on its major capsid protein, a virulence determinant ...
Antigen Tests. Antigen tests detect viral proteins directly from a sample without amplification; therefore, false negatives may ... Throughout the COVID-19 pandemic, both PCR and rapid antigen testing emerged as integral to slowing the spread of the virus. ... Tests that do not use amplification, such as antigen tests, might not achieve early detection because there are not enough ... PCR tests are more sensitive than antigen tests. PCR tests amplify genetic material from the virus; therefore, they can detect ...
J:10835 Kubota H, et al., Identification and gene cloning of a new phosphatidylinositol-linked antigen expressed on mature ...
Mark HLA class I is most tightly linked to levels of tapasin compared with other antigen-processing proteins in glioblastoma ... Mark The structure of songbird MHC class I reveals antigen binding that is flexible at the N-terminus and static at the C- ...
... see also record for pancreas-specific antigen & pancreas cancer-associated antigen, which is different from oncofetal antigens ... 5T4 oncofetal antigen, human; B-OFA protein; OFA-I antigen; OFA-I-1 antigen; XOF antigen; beta-oncofetal antigen; ... oncofetal antigen GP190; oncofetal antigen I; oncofetal antigen M2A; oncofetal antigen gp87; oncofetal glial antigen; oncofetal ... oncofetal antigens. Subscribe to New Research on oncofetal antigens see also record for pancreas-specific antigen & pancreas ...
Pure VIRAL ANTIGENS for use in immunoassays and histochemistry applications * Sample Histochemistry fixation & Saponin Protocol ... Pure VIRAL ANTIGENS for use in immunoassays and histochemistry applications * Sample Histochemistry fixation & Saponin Protocol ...
  • In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. (wikipedia.org)
  • The reaction between an antigen and an antibody is called the antigen-antibody reaction. (wikipedia.org)
  • Using the "lock and key" metaphor, the antigen can be seen as a string of keys (epitopes) each of which matches a different lock (antibody). (wikipedia.org)
  • Now that you know what an antigen and antibody are, let us consider the interaction between them. (sigmaaldrich.com)
  • The strength of interaction between antibody and antigen at single antigenic sites can be described by the affinity of the antibody for the antigen. (sigmaaldrich.com)
  • Within each antigenic site, the variable region of the antibody "arm" interacts through weak noncovalent forces with antigen at numerous sites. (sigmaaldrich.com)
  • Avidity is perhaps a more informative measure of the overall stability or strength of the antibody-antigen complex. (sigmaaldrich.com)
  • It is controlled by three major factors: antibody epitope affinity, the valence of both the antigen and antibody, and the structural arrangement of the interacting parts. (sigmaaldrich.com)
  • Ultimately these factors define the specificity of the antibody, that is, the likelihood that the particular antibody is binding to a precise antigen epitope. (sigmaaldrich.com)
  • Cross-reactivity refers to an antibody or population of antibodies binding to epitopes on other antigens. (sigmaaldrich.com)
  • This can be caused either by low avidity or specificity of the antibody or by multiple distinct antigens having identical or very similar epitopes. (sigmaaldrich.com)
  • These are of a weak, noncovalent nature, yet some of the associations between antigen and antibody can be quite strong. (sigmaaldrich.com)
  • The time taken to reach equilibrium is dependent on the rate of diffusion and the affinity of the antibody for the antigen and can vary widely. (sigmaaldrich.com)
  • The affinity constant for antibody-antigen binding can span a wide range, extending from below 105/mol to above 1012/mol. (sigmaaldrich.com)
  • Quantitative measurements of antibody affinity for antigen can be made by equilibrium dialysis. (sigmaaldrich.com)
  • The bonds that hold the antigen to the combining site of any antibody are noncovalent, and, hence, they are reversible in nature. (sigmaaldrich.com)
  • Usually there are multiple bond formations observed, ensuring relatively tight binding between antibody and antigen. (sigmaaldrich.com)
  • Two children with relapsed and refractory pre-B-cell ALL received infusions of T cells transduced with anti-CD19 antibody and a T-cell signaling molecule (CTL019 chimeric antigen receptor T cells), at a dose of 1.4×10(6) to 1.2×10(7) CTL019 cells per kilogram of body weight. (nih.gov)
  • An antigen (from antibody-generating ) or immunogen is a molecule that sometimes stimulates an immune response. (wikidoc.org)
  • Not surprisingly, blood type A individuals have the least aggressive antibody immune response against the T and probably Tn antigens. (dadamo.com)
  • So the hypothesis goes that because of the lower level of antibody against T and Tn antigens or stumps, and because of this tendency for the immune system of A's to be a bit confused or disinclined to attack Tn antigens, blood type A is at an immunologic disadvantage in attacking any cell bearing these T and Tn antigenic markers. (dadamo.com)
  • B-cells , which express antibody, can very efficiently present the antigen to which their antibody is directed, but are inefficient APC for most other antigens. (wikidoc.org)
  • Together, these modifications provide a specific set of instructions to the innate immune system to direct the elimination of antibody-bound antigens. (harvard.edu)
  • Here, we show that antibody glycosylation is determined in an antigen- and pathogen-specific manner during HIV infection. (harvard.edu)
  • Moreover, while dramatic differences exist in bulk IgG glycosylation among individuals in distinct geographical locations, immunization is able to overcome these differences and elicit antigen-specific antibodies with similar antibody glycosylation patterns. (harvard.edu)
  • Additionally, distinct vaccine regimens induced different antigen-specific IgG glycosylation profiles, suggesting that antibody glycosylation is not only programmable but can be manipulated via the delivery of distinct inflammatory signals during B cell priming. (harvard.edu)
  • These data strongly suggest that the immune system naturally drives antibody glycosylation in an antigen-specific manner and highlights a promising means by which next-generation therapeutics and vaccines can harness the antiviral activity of the innate immune system via directed alterations in antibody glycosylation in vivo. (harvard.edu)
  • This product is intended to be used as a blocking antigen for antibody competition assays. (novusbio.com)
  • This recombinant antigen is only intended to be used as a blocking agent to confirm antibody specificity with the corresponding antibody, catalog number NBP1-86203. (novusbio.com)
  • Isolation of the target antigen of human anti-tubular basement membrane antibody-associated interstitial nephritis. (jci.org)
  • We determined the serum level of antibody to hepatitis B surface antigen (anti-HBsAg) in 273 randomly selected 7-9-year-old schoolchildren from Zanjan City, Islamic Republic of Iran, who had been fully vaccinated against hepatitis B starting at birth. (who.int)
  • Several of these corresponding residues in the mouse monoclonal antibody are known to interact with the antigen. (lu.se)
  • In conclusion, critical residues important for maintaining a human antigen-specific binding site during the process of in vitro antibody evolution were defined. (lu.se)
  • Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. (wikipedia.org)
  • in some instances, however, antibodies may cross-react to bind more than one antigen. (wikipedia.org)
  • Antibodies usually do not react with self-antigens due to negative selection of T cells in the thymus and B cells in the bone marrow. (wikipedia.org)
  • The diseases in which antibodies react with self antigens and damage the body's own cells are called autoimmune diseases. (wikipedia.org)
  • But, by 1903, he understood that an antigen induces the production of immune bodies (antibodies) and wrote that the word antigen is a contraction of antisomatogen (Immunkörperbildner). (wikipedia.org)
  • Most antigens have the potential to be bound by multiple antibodies, each of which is specific to one of the antigen's epitopes. (wikipedia.org)
  • Immunoglobulin-binding protein - Proteins such as protein A, protein G, and protein L that are capable of binding to antibodies at positions outside of the antigen-binding site. (wikipedia.org)
  • While antigens are the "target" of antibodies, immunoglobulin-binding proteins "attack" antibodies. (wikipedia.org)
  • T-dependent antigen - Antigens that require the assistance of T cells to induce the formation of specific antibodies. (wikipedia.org)
  • The US Food and Drug Administration (FDA) today approved the first rapid diagnostic test to spot antibodies to both HIV types 1 and 2 as well as the HIV-1 p24 antigen. (medscape.com)
  • The Alere Determine HIV-1/2 Ag/Ab Combo test, manufactured by Orgenics of Yavne, Israel, can detect HIV antibodies and the HIV-1 p24 antigen in human serum, plasma, and venous or fingerstick whole-blood specimens. (medscape.com)
  • The HIV-1 antigen is an earlier tip-off to HIV-1 infection than HIV-1 antibodies by themselves. (medscape.com)
  • The new test can tell the difference between acute vs established HIV-1 infections when the blood specimen tests positive for the p24 antigen, but negative for HIV-1 and HIV-2 antibodies. (medscape.com)
  • Your immune cells make antibodies to recognize and destroy harmful antigens. (clevelandclinic.org)
  • Antibodies are very specific to the antigens they recognize and destroy. (clevelandclinic.org)
  • Your body defends itself against harmful antigens with chemicals called antibodies. (clevelandclinic.org)
  • If it's a fit, the B-cell makes chemicals called antibodies that all have the same shape to recognize the antigen. (clevelandclinic.org)
  • Antibodies lock on (bind) to antigens so that your immune system can destroy them. (clevelandclinic.org)
  • The multivalency of most antigens and antibodies enables them to interact to form a precipitate. (sigmaaldrich.com)
  • The specific association of antigens and antibodies is dependent on hydrogen bonds, hydrophobic interactions, electrostatic forces, and Van der Waals forces. (sigmaaldrich.com)
  • Like antibodies, antigens can be multivalent, either through multiple copies of the same epitope, or through the presence of multiple epitopes that are recognized by multiple antibodies. (sigmaaldrich.com)
  • Affinity constants can be determined for monoclonal antibodies, but not for polyclonal antibodies, as multiple bond formations take place between polyclonal antibodies and their antigens. (sigmaaldrich.com)
  • It is so rare to find the T antigen in healthy tissue, that we actually have antibodies against it. (dadamo.com)
  • All humans normally possess antibodies that react with the Thomsen-Friedenreich (T) and the Tn antigens. (dadamo.com)
  • Host Response to Tumors The immune response to foreign antigens consists of Humoral mechanisms (eg, antibodies) Cellular mechanisms (See also Tumor Antigens. (msdmanuals.com)
  • The global market for tumor-specific antigen should grow from $1.8 billion in 2018 to $2.4 billion by 2023 at a compound annual growth rate (CAGR) of 6.2% for the period of 2018-2023. (bccresearch.com)
  • The Sofia 2 SARS Antigen FIA can detect a COVID-19 infection off a sample within 15 minutes, according to its maker Quidel. (massdevice.com)
  • San Diego-based Quidel describes the Sofia 2 SARS Antigen FIA as a rapid point-of-care test to be used with the Sofia 2 fluorescent immunoassay analyzer. (massdevice.com)
  • The EUA for our Sofia 2 SARS Antigen FIA allows us to arm our healthcare workers and first responders with a frontline solution for COVID-19 diagnosis, accelerating the time to diagnosis and potential treatment of COVID-19 for the patient," Quidel CEO Douglas Bryant said in a May 8 news release. (massdevice.com)
  • The Sofia 2 SARS Antigen FIA, with the Sofia 2 analyzer, provides automated and objective results in 15 minutes, allowing for testing of patients suspected of COVID-19/2019-nCoV in near-patient testing environments. (who.int)
  • It remains to be established whether chimeric antigen receptor T cells have clinical activity in acute lymphoblastic leukemia (ALL). (nih.gov)
  • In addition, the chimeric antigen receptor T cells were observed in the cerebrospinal fluid (CSF), where they persisted at high levels for at least 6 months. (nih.gov)
  • cytokine blockade with etanercept and tocilizumab was effective in reversing the syndrome and did not prevent expansion of chimeric antigen receptor T cells or reduce antileukemic efficacy. (nih.gov)
  • Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. (wikipedia.org)
  • Immunochemical techniques capitalize upon the extreme specificity, at the molecular level, of each immunoglobulin for its antigen, even in the presence of high levels of contaminating molecules. (sigmaaldrich.com)
  • Chimeric antigen receptor-modified T cells with specificity for CD19 have shown promise in the treatment of chronic lymphocytic leukemia (CLL). (nih.gov)
  • IGRAs are endowed with great specificity, as the antigens used are almost exclusively expressed by the Mycobacterium tuberculosis (MTB) complex, but not Mycobacterium bovis bacille Calmette-Guerin (BCG) [ 1 - 3 ]. (ersjournals.com)
  • Antigens are usually proteins or sugars (polysaccharides) found on the outside of things like cells or viruses. (clevelandclinic.org)
  • Antigens are usually proteins or polysaccharides . (wikidoc.org)
  • Non-microbial exogenous (non-self) antigens can include pollen, egg white, and proteins from transplanted tissues and organs or on the surface of transfused blood cells. (wikidoc.org)
  • Antigen tests quickly detect fragments of proteins found on or within the virus - with analysis of samples collected from the nasal cavity using swabs. (massdevice.com)
  • The main task of the MHC-I proteins is to present antigens, which may impose a hazard to the cell. (lu.se)
  • The mechanism of this antigen presentation involves the formation of a so-called MHC-I peptide-loading complex (PLC) where several proteins are involved. (lu.se)
  • B-cells have special parts (receptors) that test the antigen to see if they fit together, like a lock and key. (clevelandclinic.org)
  • Once they had successfully achieved this, the researchers used a trick to fish those receptors out of the preparation that had survived the process and were still functional: due to the strong interaction between the receptor complex and the antigen, they were able to 'fish' one of the most medically important immune receptor complexes. (news-medical.net)
  • And the main difference between these B cell receptors and T cell receptors on this is something we're gonna talk about more in just a moment is that B cell receptors will actually bind directly to antigens. (pearson.com)
  • The ADVIA Centaur cPSA assay quantitatively measures complexed prostate-specific antigen (cPSA) in human serum. (cdc.gov)
  • Unexplained increase of serum carcinoembryonic antigen: don't forget the thyroid! (degruyter.com)
  • Total, free and complex prostate specific antigens (PSA) were measured among men age 40 years and older. (cdc.gov)
  • Antigen-presenting cells present antigens in the form of peptides on histocompatibility molecules. (wikipedia.org)
  • Carcinoembryonic antigen (CEA) is glycoprotein associated with various functions of endothelial cells, including adhesion, proliferation, and migration. (degruyter.com)
  • Der Antigen-Schnelltest für das neuartige Coronavirus (SARS-Cov-2) ist ein in-vitro-diagnostischer Test zum qualitativen Nachweis neuartiger Coronavirus-Antigene in Nasopharyngealabstrichen unter Verwendung der immunochromatographischen Schnellmethode. (rutronik.com)
  • Siemens Healthineers on Wednesday announced the launch of a rapid antigen test kit in Europe to detect coronavirus infections but warned the industry may struggle to meet a surge in demand. (aljazeera.com)
  • A prospective cohort study reassortant influenza A(H5N8) viruses in domestic ducks, comparing a rapid antigen test with quantitative reverse eastern China. (cdc.gov)
  • In-office, rapid stool antigen tests allow the specimen to be placed directly into a single device used for testing, and results can be read within 10 minutes. (medscape.com)
  • Throughout the COVID-19 pandemic, both PCR and rapid antigen testing emerged as integral to slowing the spread of the virus. (cepheid.com)
  • Rapid antigen tests - like the two seen here showing negative results - are much faster and easier to perform but are less sensitive than PCR tests. (weforum.org)
  • The SARS-CoV-2 Antigen Rapid Diagnostic test (RDT) training package is a structured comprehensive collection of training resources and tools to enable relevant institutions to organize, run and evaluate training of trainers and/or training of health workers who will be performing SARS-CoV-2 testing using Antigen RDTs. (who.int)
  • This is addressed in the SARS-CoV-2 antigen-detecting rapid diagnostic tests: An implementation guide and in policy guidance issued by the World Health Organization. (who.int)
  • Those leagues use PCR tests, which are more accurate than rapid antigen tests, but also more expensive and require lab processing. (axios.com)
  • But rapid antigen tests can cost as little as $5 , and entirely at-home tests take labs out of the picture. (axios.com)
  • Mina has argued while rapid tests will miss some cases that PCR diagnostics would pick up, antigen tests are particularly good at identifying when people are most contagious. (axios.com)
  • The study results show that at-home antigen tests are more likely to detect COVID-19 within the first week of infection when a person without symptoms tests three times, at 48-hour intervals, and a person with symptoms tests twice, according to the study by UMass Chan researchers and partners supported by the National Institutes of Health (NIH) Rapid Acceleration of Diagnostics (RADx) Tech program. (umassmed.edu)
  • The UMass Chan team has been working for the past year to ensure that the best evidence was generated for performance of rapid antigen tests in asymptomatic people, according to Apurv Soni, MD, PhD'21, assistant professor of medicine and principal investigator on the study. (umassmed.edu)
  • To our knowledge, this is one of the largest studies to date that examined COVID-19 rapid antigen test performance serially over two weeks. (umassmed.edu)
  • The results of this study show that rapid tests detect the omicron as well as delta variants and that serial testing with antigen tests remains a useful way to detect infection," said co-author Nathaniel Hafer, PhD, assistant professor of molecular medicine and lead investigator of the RADx Tech Clinical Studies Core Logistics Team. (umassmed.edu)
  • These are the PCR test and the Rapid Antigen Test. (island.lk)
  • The PCR test is conducted in a centralized laboratory, while the Rapid Antigen Test can be carried out on the spot. (island.lk)
  • Discover 115 products from Rapid Antigen Test Kit manufacturers, suppliers, distributors, and dealers across India. (tradeindia.com)
  • Rapid Antigen Test Kit product price in India ranges from 20 to 1,00,000.0 INR and minimum order requirements from 1 to 1,00,000. (tradeindia.com)
  • Whether you're looking for Coviself Covid 19 Rapid Antigen Test For Self Test Kit, Rapid Antigen Test Kit Covid, Covid-19 Antigen Rapid Test Kit etc, you can explore and find the best products from Tradeindia. (tradeindia.com)
  • We offer a wide range of Rapid Antigen Test Kit selections in various locations including Delhi, Jaipur, Mumbai, Pune, Chennai and many more. (tradeindia.com)
  • FDA has issued a first-of-its-kind emergency use authorization for Quidel 's COVID-19 antigen test, which enables rapid diagnosis of virus infection. (massdevice.com)
  • DNA sequence variation within human leukocyte antigen (HLA) genes mediate susceptibility to a wide range of human diseases. (nih.gov)
  • LY6G5C belongs to a cluster of leukocyte antigen-6 (LY6) genes located in the major histocompatibility complex (MHC) class III region on chromosome 6. (nih.gov)
  • Discover related pathways, diseases and genes to CFAP299 Recombinant Protein Antigen (NBP1-86203PEP). (novusbio.com)
  • Genes and antigens of parasites : a laboratory manual, the proceedings of a course held at the Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil, 14 November-17 December, 1983 / organized and edited by Carlos M. Morel. (who.int)
  • No single antigen was of special importance as an inducer of sensitisation. (bmj.com)
  • An H. Pylori antigen test also can see if antibiotic treatment for an H. Pylori infection has worked. (kidshealth.org)
  • If you have questions about the H. Pylori antigen test or what the test results mean, talk to your doctor. (kidshealth.org)
  • Helicobacter pylori antigen testing is approved by the US Food and Drug Administration (FDA) for use as a noninvasive diagnostic test for H pylori infection and as a test to determine eradication after treatment. (medscape.com)
  • H pylori antigen testing has 3 distinct forms. (medscape.com)
  • H pylori antigen testing uses one fresh random stool sample. (medscape.com)
  • H pylori antigen testing is not typically performed within a laboratory panel but as a standalone test. (medscape.com)
  • H pylori antigen is a protein constituent of the H pylori bacterium, which is shed in human stool. (medscape.com)
  • The presence of antigens in the body may trigger an immune response. (wikipedia.org)
  • Immunodominant antigens - Antigens that dominate (over all others from a pathogen) in their ability to produce an immune response. (wikipedia.org)
  • IGRAs, commercially available as QuantiFERON-TB Gold In-Tube test (QFT) (QIAGEN, Germantown, MD, USA) and T-SPOT.TB (Oxford Immunotec Ltd, Abingdon, UK), are based on the detection of a T-cell immune response towards RD1 antigens (ESAT-6 and CFP-10), with the addition of the TB7.7 antigen for the QFT only [ 1 ]. (ersjournals.com)
  • In 2014, Genome-Wide Association Study (GWAS) was performed with 2,398 individuals with laryngeal squamous cell carcinoma cases and 2,804 cancer-free controls from Chinese populations, and identified a novel susceptibility loci in complex human leukocyte antigen (HLA), which plays crucial role in immune response. (who.int)
  • If that particular T cell's unique receptor is a match for the antigen, it alerts the rest of the immune system to attack. (clevelandclinic.org)
  • On their surface, these special white blood cells carry a receptor that recognizes antigens . (news-medical.net)
  • With the help of cryo-electron microscopy, biochemists and structural biologists from Goethe University Frankfurt, in collaboration the University of Oxford and the Max Planck Institute of Biophysics, were able to visualize the whole T-cell receptor complex with bound antigen at atomic resolution for the first time. (news-medical.net)
  • They carry a special receptor called the T-cell receptor on their surface that recognizes antigens - small protein fragments of bacteria, viruses and infected or cancerous body cells - which are presented by specialized immune complexes. (news-medical.net)
  • After binding of a suitable antigen to the receptor, a signaling pathway is triggered inside the T cell that 'arms' the cell for the respective task. (news-medical.net)
  • Researchers led by Lukas Sušac, Christoph Thomas, and Robert Tampé from the Institute of Biochemistry at Goethe University Frankfurt, in collaboration with Simon Davis from the University of Oxford and Gerhard Hummer from the Max Planck Institute of Biophysics, have now succeeded for the first time in visualizing the structure of a membrane-bound T-cell receptor complex with bound antigen. (news-medical.net)
  • A comparison of the antigen-bound structure captured using cryo-electron microscopy with that of a receptor without antigen provides the first clues to the activation mechanism. (news-medical.net)
  • For the structural analysis, the researchers chose a T-cell receptor used in immunotherapy to treat melanoma and which had been optimized for this purpose in several steps in such a way that it binds its antigen as tightly as possible. (news-medical.net)
  • A particular challenge on the way to structure determination was to isolate the whole antigen receptor assembly consisting of eleven different subunits from the cell membrane. (news-medical.net)
  • The subsequent images collected at the cryo-electron microscope delivered groundbreaking insights into how the T-cell receptor works, as Tampé summarises: 'On the basis of our structural analysis, we were able to show how the T-cell receptor assembles and recognizes antigens and hypothesize how signal transduction is triggered after antigen binding. (news-medical.net)
  • The co-receptor CD8 is known to approach the T-cell receptor after antigen binding and to stimulate the transfer of phosphate groups to its intracellular part. (news-medical.net)
  • Chimeric antigen receptor-modified T cells are capable of killing even aggressive, treatment-refractory acute leukemia cells in vivo. (nih.gov)
  • Tumor antigens can also be on the surface of the tumor in the form of, for example, a mutated receptor, in which case they will be recognized by B cells . (wikidoc.org)
  • every B and T cell is going to have a single type of antigen receptor, and that's going to be specific. (pearson.com)
  • Adoptive cell therapy (ACT) with chimeric antigen receptor T (CAR-T) cells can restore the activity of exhausted T cell through reprogramming and is widely used in the treatment of relapsed/refractory (r/r) hematological malignancies. (hindawi.com)
  • The most active T cell endogenous inhibitory pathway is the immunoglobulin superfamily such as CD28/cytotoxic T lymphocyte antigen-4 (CTLA-4): B7-1/B7-2 receptor/ligand grouping, which plays a central role in coordinating immune responses [ 7 , 8 ]. (hindawi.com)
  • These professional APCs are very efficient at internalizing antigen, either by phagocytosis or by receptor-mediated endocytosis , and then displaying a fragment of the antigen, bound to a class II MHC molecule, on their membrane. (wikidoc.org)
  • COVID-19: What's the difference between PCR and antigen tests? (weforum.org)
  • On Tuesday, the FDA granted emergency authorization to Ellume's over-the-counter antigen COVID-19 test for fully at-home usage - akin to a standard home pregnancy test. (axios.com)
  • The FDA's safety communication recommends people perform repeat, or serial, testing following a negative result on any at-home COVID-19 antigen test. (umassmed.edu)
  • Findings from a new study led by UMass Chan Medical School researchers are the basis for a safety communication issued by the U.S. Food and Drug Administration (FDA) Aug. 11 regarding serial use of at-home antigen tests for COVID-19. (umassmed.edu)
  • FDA commissioner Dr. Stephen M. Hahn and CDRH director Dr. Jeffrey E. Shuren in a statement said antigen tests will play a "critical role in the fight against COVID-19. (massdevice.com)
  • Still, the described the antigen tests as an "important in the overall response against COVID-19 as they can generally be produced at a lower cost than PCR tests. (massdevice.com)
  • The paralleled testing of nucleic acid testing in key areas where there are more confirmed and asymptomatic cases and antigen in non-key areas where there are fewer cases continued to be carried out throughout the city on Sunday. (globalsecurity.org)
  • Tests that do not use amplification, such as antigen tests, might not achieve early detection because there are not enough viruses, bacteria, or other pathogens present in a patient's sample. (cepheid.com)
  • MSTA (Mumps Skin Test Antigen ) is a suspension of killed mumps virus used when detection of a delayed-hypersensitivity (DH) reaction is desired. (rxlist.com)
  • MSTA, Mumps Skin Test Antigen, is indicated when detection of a delayed-hypersensitivity (DH) reaction is desired. (rxlist.com)
  • Serial testing with an at-home antigen test twice over 48 hours resulted in detection of more than 90 percent of infections when symptomatic people started testing within the first week of infection, the study reports. (umassmed.edu)
  • Other quicker diagnostic tests focus on the detection of viral antigens in saliva or swab samples. (uni-potsdam.de)
  • A key role of the immune system is detection of these antigens to permit subsequent targeting for eradication. (msdmanuals.com)
  • The Sofia 2 SARS Antigen Fluorescent Immunoassay (FIA) uses advanced immunofluorescence-based lateral flow technology in a sandwich design for qualitative detection of nucleocapsid protein from SARS-CoV-2. (who.int)
  • The antigen processing and loading onto MHC-I molecules takes place in the intracellular environment, when the antigen-MHC-I complex is transferred to the cell surface for detection by circulating CD8 + T cells. (lu.se)
  • Antigen testing is done to diagnose viral infections, monitor and screen for certain conditions and determine whether a donor is a good match for a transplant. (clevelandclinic.org)
  • Endogenous antigens are antigens that have been generated within the cell, as a result of normal cell metabolism , or because of viral or intracellular bacterial infection . (wikidoc.org)
  • More common are antigens that are presented by tumor cells and normal cells, and they are called tumor-associated antigens (TAAs) . (wikidoc.org)
  • Immunization of a murine host with SinH-based antigens elicited significant protection against various strains of the pandemic ExPEC sequence type 131 (ST131) as well as multiple sequence types in two distinct models of infection (colonization and bacteremia ). (bvsalud.org)
  • Antigens (ANN-tih-jins) are substances that trigger the immune system to fight infection. (kidshealth.org)
  • Exogenous antigens come from foreign substances that can enter your body through your nose, your mouth or cuts in your skin. (clevelandclinic.org)
  • The rotavirus antigen test detects rotavirus in the feces. (medlineplus.gov)
  • In this test, a stool sample is tested to check for H. pylori (pie-LOR-eye) antigens. (kidshealth.org)
  • The device is an antigen test and, internally, works like the home tests that show the results using lines similar to a pregnancy test. (hackaday.com)
  • Yi Lin, a local resident from Jing'an district, told the Global Times on Sunday that she and her husband and her elder son took the antigen self-test while her younger son and her parents living in a separate apartment in another building in the same compound took nucleic acid tests since there is a close contact of confirmed patients in their residential building. (globalsecurity.org)
  • Tao suggested that the results of the antigen self-test should be uploaded to the nation's unified system like it's done with nucleic acid test results, which are linked to personal information and can be checked through mobile phones. (globalsecurity.org)
  • Meanwhile, some mini apps have been developed by some tech companies for users to upload and record their antigen self-test results. (globalsecurity.org)
  • Our MSTA (Mumps Skin Test Antigen) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication. (rxlist.com)
  • MSTA®, Mumps Skin Test Antigen , is a sterile suspension of killed mumps virus for intradermal use. (rxlist.com)
  • The skin test antigen is formulated to contain at least 40 complement fixing units (CFU) per mL, at the time of release, as determined by the Complement-Fixation Test. (rxlist.com)
  • If these conditions exist, Mumps Skin Test Antigen should not be administered. (rxlist.com)
  • Care should be taken to inject the test antigen intradermally. (rxlist.com)
  • Participants took an at-home antigen test using one of three retail test kits, which are available in the United States, and collected a sample for a molecular PCR test, using nasal swabs for both types of test samples. (umassmed.edu)
  • Among those who did not have symptoms but had an infection lasting at least two days based on PCR testing, serial testing three times with an at-home antigen test at 48-hour intervals detected more than 75 percent of infections, an increase from roughly 60 percent sensitivity after testing just twice. (umassmed.edu)
  • FDA expects more antigen test authorizations to follow. (massdevice.com)
  • Hahn and Shuren said negative results from antigen tests may need to be double-checked with a PCR test. (massdevice.com)
  • Once multiple manufacturers enter the antigen tests market, there's the potential to scale to test millions of Americans per day. (massdevice.com)
  • CDC is expecting a 3-10 month nationwide shortage of Aplisol, a product of Par Pharmaceuticals, and one of two purified-protein derivative (PPD) tuberculin antigens licensed by the Food and Drug Administration (FDA) for use in performing tuberculin skin tests. (cdc.gov)
  • The Rh blood group includes this gene which encodes both the RhC and RhE antigens on a single polypeptide and a second gene which encodes the RhD protein. (nih.gov)
  • An antigen is any kind of marker - like a protein or string of amino acids - that your immune system can recognize. (clevelandclinic.org)
  • These antigens are sometimes normal parts of a cell that act differently in tumor cells (for example, a tumor cell might make much more of a particular protein than a normal cell). (clevelandclinic.org)
  • There are currently no images for CFAP299 Recombinant Protein Antigen (NBP1-86203PEP). (novusbio.com)
  • A recombinant protein antigen with a N-terminal His6-ABP tag corresponding to human C4ORF22. (novusbio.com)
  • Shanghai residents continue to take antigen self-tests on Sunday since the city started on Saturday to try out the practice of combining nucleic acid testing and antigen self-testing to improve testing efficiency and detect latent infections in time. (globalsecurity.org)
  • PCR tests and antigen tests are the two main ways to detect SARS-CoV-2. (weforum.org)
  • Epitope - the distinct surface features of an antigen, its antigenic determinant. (wikipedia.org)
  • If you want to read more about antigen tests , we covered that. (hackaday.com)
  • PCR tests are more sensitive than antigen tests. (cepheid.com)
  • In non-key areas, those who take antigen self-tests and get a positive result are required to further take nucleic acid tests and will be quarantined immediately before their results come out. (globalsecurity.org)
  • Tao Lina, a Shanghai-based expert on infectious diseases, told the Global Times on Sunday that the three characteristics of antigen self-tests - swiftness, being able to be easily used by one individual and easy to be operated by both young and senior people - can serve as a new model to fight against the Omicron variant. (globalsecurity.org)
  • Using less-accurate antigen tests would inevitably result in both false negatives - meaning cases that would be missed - and false positives. (axios.com)
  • An implication of findings from this study is that people who are suspected to be infected with the SARS-CoV-2 virus but have not developed symptoms should exercise caution, such as wearing masks and avoiding crowded places, for at least six days until three at-home antigen tests taken 48 hours apart have been performed, according to the study's authors. (umassmed.edu)
  • Tumor antigens or Neoantigens are those antigens that are presented by MHC I or MHC II molecules on the surface of tumor cells . (wikidoc.org)
  • Although almost every cell in the body is an APC, since it can present antigen to CD8 + T cells via MHC class I molecules, the term is often limited to those specialized cells that can prime T cells (i.e., activate a T cell that has not been exposed to antigen, termed a naive T cell ). (wikidoc.org)
  • To help distinguish between the two types of APCs, those that express MHC class II molecules are often called professional antigen-presenting cells . (wikidoc.org)
  • Cross-reactivity is sometimes desirable when one wants general binding to a related group of antigens or when attempting cross-species labeling when the antigen epitope sequence is not highly conserved during evolution. (sigmaaldrich.com)
  • You might hear these called tumor-associated antigens (TAA), tumor-specific antigens (TSA), neoantigens or oncogenic antigens. (clevelandclinic.org)
  • Both patient antisera containing alpha TBM-Ab were also highly reactive with R3M-1, the 48,000-mol-wt rabbit glycoprotein antigen of experimental alpha TBM disease. (jci.org)
  • depending on the antigen and the type of the histocompatibility molecule, different types of T cells will be activated. (wikipedia.org)
  • Cells present their antigens to the immune system via a histocompatibility molecule . (wikidoc.org)
  • Depending on the antigen presented and the type of the histocompatibility molecule, several types of immune cells can become activated. (wikidoc.org)
  • The T cell recognizes and interacts with the antigen-class II MHC molecule complex on the membrane of the antigen-presenting cell. (wikidoc.org)
  • Any molecule capable of being recognized by the immune system is considered an antigen. (msdmanuals.com)
  • Superantigen - A class of antigens that cause non-specific activation of T-cells, resulting in polyclonal T-cell activation and massive cytokine release. (wikipedia.org)
  • T-independent antigen - Antigens that stimulate B cells directly. (wikipedia.org)
  • Antigens are found on viruses, bacteria, tumors and normal cells of your body. (clevelandclinic.org)
  • This means that your body recognizes your own cells as you, but other antigens as intruders. (clevelandclinic.org)
  • Endogenous antigens exist on cells inside your body. (clevelandclinic.org)
  • What are antigen-presenting cells? (clevelandclinic.org)
  • Antigen-presenting cells help the immune system mount its attack. (clevelandclinic.org)
  • There are three types of antigen-presenting cells in your body: macrophages, dendritic cells and B cells. (clevelandclinic.org)
  • In fact, you'll sometimes hear them called "professional" antigen-presenting cells. (clevelandclinic.org)
  • When one of these specialized cells comes across an antigen, it devours the antigen, breaks it apart and displays parts of the antigen on its cell surface. (clevelandclinic.org)
  • The T cells inspect the bits of antigen to decide if they recognize the invader. (clevelandclinic.org)
  • When an antigen enters your body, the B-cells of your immune system inspect it. (clevelandclinic.org)
  • Once your immune system has seen an antigen, it has special cells that remember it, allowing your body to create a faster and more effective response if it invades again - this is called immunological memory. (clevelandclinic.org)
  • By endocytosis or phagocytosis , these antigens are taken into the antigen-presenting cells (APCs) and processed into fragments. (wikidoc.org)
  • These antigens can sometimes be presented by tumor cells and never by the normal ones. (wikidoc.org)
  • Cytotoxic T lymphocytes that recognize these antigens may be able to destroy the tumor cells before they proliferate or metastasize . (wikidoc.org)
  • T cells cannot bind native antigens, but require that they are processed by APCs, while B cells can be activated by native ones. (wikidoc.org)
  • This association afforded us a unique opportunity to identify a sarcoidosis-specific antigen recognized by AV2S3+ T cells. (jci.org)
  • To identify candidates for the postulated sarcoidosis-specific antigen, lung cells from 16 HLA-DRB1*0301pos patients were obtained by bronchoalveolar lavage. (jci.org)
  • peptides bound to HLA-DR17 from bronchoalveolar lavage cells of sarcoidosis patients were analyzed in order to identify target antigens of the autoimmune response (see the related article beginning on page 3576). (jci.org)
  • Many malignant cells (such as those found in breast and stomach cancer) develop a tumor marker called the Thomsen-Friedenreich (T) antigen. (dadamo.com)
  • This antigen is suppressed in normal healthy cells, much like a rock is covered over by water at high tide. (dadamo.com)
  • Healthy cells do not normally express the T or Tn antigen, which are 'encrypted' or covered up by polysaccharides much the same way that a rock is covered by water at high tide. (dadamo.com)
  • In malignant or pre-malignant cells, the ability to synthesize the polysaccharides which normally cover the T antigen is often lost, which causes T to be 'expressed' or uncovered, much like a falling tide will often uncover previously hidden rocks at a low tide. (dadamo.com)
  • In this example, the T and Tn antigens are the stumps found in cancer, while the well-groomed yard has bushes, shrubs, and flowers, that correspond to the ABO markers and other antigens found on healthy cells. (dadamo.com)
  • One of the functions of these T and Tn antigens is to promote cancer cell adhesion----the ability for the cancer cell to stick to other cells including healthy cells. (dadamo.com)
  • Antigen presentation stimulates T cells to become either "cytotoxic" CD8+ cells or "helper" CD4+ cells. (wikidoc.org)
  • Dendritic cells , which have the broadest range of antigen presentation, and are probably the most important APC. (wikidoc.org)
  • Many tumor cells produce antigens, which may be released in the bloodstream or remain on the cell surface. (msdmanuals.com)
  • Tumor-associated antigens (TAAs) are relatively restricted to tumor cells. (msdmanuals.com)
  • Tumor-specific antigens (TSAs) are unique to tumor cells. (msdmanuals.com)
  • However, several antigens with selective expression on the surface of tumor cells are not associated with the major histocompatibility complex and may be candidates for therapeutic targeting. (msdmanuals.com)
  • References Many tumor cells produce antigens, which may be released in the bloodstream or remain on the cell surface. (msdmanuals.com)
  • You might hear your own body's antigens referred to as "self" and viruses, bacteria and other harmful antigens referred to as "non-self. (clevelandclinic.org)
  • three known antigens, designated Jk a , Jk b , and Jk3, all of which are encoded by a gene known as SLC14A1 (solute carrier family 14, member 1). (britannica.com)
  • We will also perform immunogenetic analyses in a human case-control cohort to assess if gene variants regulating antigen presentation are associated to PD risk. (lu.se)
  • Seluruh penonton yang hadir telah menjalani swab antigen satu hari sebelum acara. (metrotvnews.com)
  • The saga of MHC-bound peptides: a renaissance for antigen presentation? (jci.org)
  • The project is done in collaboration with Kajsa M. Paulsson, head of the Antigen Presentation group at the Faculty of Medicine. (lu.se)
  • The aim of this project is to investigate if antigen presentation, a key process linking innate and adaptive immune responses, is a risk factor for PD. (lu.se)
  • Although a limited number of immunodominant peptide epitopes are consistently observed in diseases such as HIV-1 infection, the relationship between immunodominance and antigen processing in humans is largely unknown. (jci.org)
  • Red blood cell antigens and special markers that your body recognizes as "self" (HLAs) are also endogenous antigens. (clevelandclinic.org)
  • In this case, they are called tumor-specific antigens (TSAs) and, in general, result from a tumor-specific mutation. (wikidoc.org)
  • Vaccines are examples of antigens in an immunogenic form, which are intentionally administered to a recipient to induce the memory function of the adaptive immune system towards antigens of the pathogen invading that recipient. (wikipedia.org)
  • Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. (wikipedia.org)
  • This training does not intend to address the implementation of Antigen RDT testing across the diagnostic network. (who.int)
  • Following a similar strategy, we evaluated the addition of six novel peptides to the QFT antigen cocktail to improve the diagnostic performance in terms of accuracy and dynamic range of interferon (IFN)-γ level in active TB patients. (ersjournals.com)
  • However, a prevalence of Tn antigens (Note: Tn Antigen is actually a precursor to T antigen or a less well developed T antigen) on a cancer cell usually denotes a highly aggressive, metastatic cancer irrespective of organ or type of cancer. (dadamo.com)
  • Hirohashi S. Tumor-associated carbohydrate antigens related to blood group carbohydrates. (dadamo.com)