Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.
A congenital bleeding disorder with prolonged bleeding time, absence of aggregation of platelets in response to most agents, especially ADP, and impaired or absent clot retraction. Platelet membranes are deficient in or have a defect in the glycoprotein IIb-IIIa complex (PLATELET GLYCOPROTEIN GPIIB-IIIA COMPLEX).
Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.
The attachment of PLATELETS to one another. This clumping together can be induced by a number of agents (e.g., THROMBIN; COLLAGEN) and is part of the mechanism leading to the formation of a THROMBUS.
Platelet membrane glycoprotein complex important for platelet adhesion and aggregation. It is an integrin complex containing INTEGRIN ALPHAIIB and INTEGRIN BETA3 which recognizes the arginine-glycine-aspartic acid (RGD) sequence present on several adhesive proteins. As such, it is a receptor for FIBRINOGEN; VON WILLEBRAND FACTOR; FIBRONECTIN; VITRONECTIN; and THROMBOSPONDINS. A deficiency of GPIIb-IIIa results in GLANZMANN THROMBASTHENIA.
Platelet membrane glycoprotein complex essential for normal platelet adhesion and clot formation at sites of vascular injury. It is composed of three polypeptides, GPIb alpha, GPIb beta, and GPIX. Glycoprotein Ib functions as a receptor for von Willebrand factor and for thrombin. Congenital deficiency of the GPIb-IX complex results in Bernard-Soulier syndrome. The platelet glycoprotein GPV associates with GPIb-IX and is also absent in Bernard-Soulier syndrome.
Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.
A high-molecular-weight plasma protein, produced by endothelial cells and megakaryocytes, that is part of the factor VIII/von Willebrand factor complex. The von Willebrand factor has receptors for collagen, platelets, and ristocetin activity as well as the immunologically distinct antigenic determinants. It functions in adhesion of platelets to collagen and hemostatic plug formation. The prolonged bleeding time in VON WILLEBRAND DISEASES is due to the deficiency of this factor.
The process whereby PLATELETS adhere to something other than platelets, e.g., COLLAGEN; BASEMENT MEMBRANE; MICROFIBRILS; or other "foreign" surfaces.
Human alloantigens expressed only on platelets, specifically on platelet membrane glycoproteins. These platelet-specific antigens are immunogenic and can result in pathological reactions to transfusion therapy.
Antibodies produced by a single clone of cells.
Drugs or agents which antagonize or impair any mechanism leading to blood platelet aggregation, whether during the phases of activation and shape change or following the dense-granule release reaction and stimulation of the prostaglandin-thromboxane system.
Univalent antigen-binding fragments composed of one entire IMMUNOGLOBULIN LIGHT CHAIN and the amino terminal end of one of the IMMUNOGLOBULIN HEAVY CHAINS from the hinge region, linked to each other by disulfide bonds. Fab contains the IMMUNOGLOBULIN VARIABLE REGIONS, which are part of the antigen-binding site, and the first IMMUNOGLOBULIN CONSTANT REGIONS. This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.
An antibiotic mixture of two components, A and B, obtained from Nocardia lurida (or the same substance produced by any other means). It is no longer used clinically because of its toxicity. It causes platelet agglutination and blood coagulation and is used to assay those functions in vitro.
The number of PLATELETS per unit volume in a sample of venous BLOOD.
Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.
Duration of blood flow after skin puncture. This test is used as a measure of capillary and platelet function.
A subnormal level of BLOOD PLATELETS.
A series of progressive, overlapping events, triggered by exposure of the PLATELETS to subendothelial tissue. These events include shape change, adhesiveness, aggregation, and release reactions. When carried through to completion, these events lead to the formation of a stable hemostatic plug.
Venoms from snakes of the subfamily Crotalinae or pit vipers, found mostly in the Americas. They include the rattlesnake, cottonmouth, fer-de-lance, bushmaster, and American copperhead. Their venoms contain nontoxic proteins, cardio-, hemo-, cyto-, and neurotoxins, and many enzymes, especially phospholipases A. Many of the toxins have been characterized.
Sites on an antigen that interact with specific antibodies.
Platelet membrane glycoprotein IIb is an integrin alpha subunit that heterodimerizes with INTEGRIN BETA3 to form PLATELET GLYCOPROTEIN GPIIB-IIIA COMPLEX. It is synthesized as a single polypeptide chain which is then postranslationally cleaved and processed into two disulfide-linked subunits of approximately 18 and 110 kDa in size.
Very large BONE MARROW CELLS which release mature BLOOD PLATELETS.
A familial coagulation disorder characterized by a prolonged bleeding time, unusually large platelets, and impaired prothrombin consumption.
Formation and development of a thrombus or blood clot in the blood vessel.
An integrin alpha subunit that primarily combines with INTEGRIN BETA1 to form the INTEGRIN ALPHA2BETA1 heterodimer. It contains a domain which has homology to collagen-binding domains found in von Willebrand factor.
Amidines substituted with a benzene group. Benzamidine and its derivatives are known as peptidase inhibitors.
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.
An integrin beta subunit of approximately 85-kDa in size which has been found in INTEGRIN ALPHAIIB-containing and INTEGRIN ALPHAV-containing heterodimers. Integrin beta3 occurs as three alternatively spliced isoforms, designated beta3A-C.
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.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
Cell adhesion molecule and CD antigen that mediates the adhesion of neutrophils and monocytes to activated platelets and endothelial cells.
A CXC chemokine that is found in the alpha granules of PLATELETS. The protein has a molecular size of 7800 kDa and can occur as a monomer, a dimer or a tetramer depending upon its concentration in solution. Platelet factor 4 has a high affinity for HEPARIN and is often found complexed with GLYCOPROTEINS such as PROTEIN C.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Laboratory examination used to monitor and evaluate platelet function in a patient's blood.
The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. (From Martindale, The Extra Pharmacopoeia, 30th ed, p5)
Peptides composed of between two and twelve amino acids.
Thrombocytopenia occurring in the absence of toxic exposure or a disease associated with decreased platelets. It is mediated by immune mechanisms, in most cases IMMUNOGLOBULIN G autoantibodies which attach to platelets and subsequently undergo destruction by macrophages. The disease is seen in acute (affecting children) and chronic (adult) forms.
The transfer of blood platelets from a donor to a recipient or reinfusion to the donor.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
A dual specificity phosphatase subtype that plays a role in intracellular signal transduction by inactivating MITOGEN-ACTIVATED PROTEIN KINASES. It has specificity for EXTRACELLULAR SIGNAL-REGULATED MAP KINASES and is primarily localized to the CELL NUCLEUS.
Fibrinolysin or agents that convert plasminogen to FIBRINOLYSIN.
A highly acidic mucopolysaccharide formed of equal parts of sulfated D-glucosamine and D-glucuronic acid with sulfaminic bridges. The molecular weight ranges from six to twenty thousand. Heparin occurs in and is obtained from liver, lung, mast cells, etc., of vertebrates. Its function is unknown, but it is used to prevent blood clotting in vivo and vitro, in the form of many different salts.
A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).
The deformation and flow behavior of BLOOD and its elements i.e., PLASMA; ERYTHROCYTES; WHITE BLOOD CELLS; and BLOOD PLATELETS.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
Any form of purpura in which the PLATELET COUNT is decreased. Many forms are thought to be caused by immunological mechanisms.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.
Bleeding or escape of blood from a vessel.
A phospholipid derivative formed by PLATELETS; BASOPHILS; NEUTROPHILS; MONOCYTES; and MACROPHAGES. It is a potent platelet aggregating agent and inducer of systemic anaphylactic symptoms, including HYPOTENSION; THROMBOCYTOPENIA; NEUTROPENIA; and BRONCHOCONSTRICTION.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
Receptors such as INTEGRIN ALPHAVBETA3 that bind VITRONECTIN with high affinity and play a role in cell migration. They also bind FIBRINOGEN; VON WILLEBRAND FACTOR; osteopontin; and THROMBOSPONDINS.
Disorders caused by abnormalities in platelet count or function.
The sum of the weight of all the atoms in a molecule.
Group of hemorrhagic disorders in which the VON WILLEBRAND FACTOR is either quantitatively or qualitatively abnormal. They are usually inherited as an autosomal dominant trait though rare kindreds are autosomal recessive. Symptoms vary depending on severity and disease type but may include prolonged bleeding time, deficiency of factor VIII, and impaired platelet adhesion.
Proteins prepared by recombinant DNA technology.
A 44-kDa highly glycosylated plasma protein that binds phospholipids including CARDIOLIPIN; APOLIPOPROTEIN E RECEPTOR; membrane phospholipids, and other anionic phospholipid-containing moieties. It plays a role in coagulation and apoptotic processes. Formerly known as apolipoprotein H, it is an autoantigen in patients with ANTIPHOSPHOLIPID ANTIBODIES.
The process of the interaction of BLOOD COAGULATION FACTORS that results in an insoluble FIBRIN clot.
Techniques for removal by adsorption and subsequent elution of a specific antibody or antigen using an immunosorbent containing the homologous antigen or antibody.
A family of transmembrane glycoproteins (MEMBRANE GLYCOPROTEINS) consisting of noncovalent heterodimers. They interact with a wide variety of ligands including EXTRACELLULAR MATRIX PROTEINS; COMPLEMENT, and other cells, while their intracellular domains interact with the CYTOSKELETON. The integrins consist of at least three identified families: the cytoadhesin receptors(RECEPTORS, CYTOADHESIN), the leukocyte adhesion receptors (RECEPTORS, LEUKOCYTE ADHESION), and the VERY LATE ANTIGEN RECEPTORS. Each family contains a common beta-subunit (INTEGRIN BETA CHAINS) combined with one or more distinct alpha-subunits (INTEGRIN ALPHA CHAINS). These receptors participate in cell-matrix and cell-cell adhesion in many physiologically important processes, including embryological development; HEMOSTASIS; THROMBOSIS; WOUND HEALING; immune and nonimmune defense mechanisms; and oncogenic transformation.
Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.
Collagen receptors are cell surface receptors that modulate signal transduction between cells and the EXTRACELLULAR MATRIX. They are found in many cell types and are involved in the maintenance and regulation of cell shape and behavior, including PLATELET ACTIVATION and aggregation, through many different signaling pathways and differences in their affinities for collagen isoforms. Collagen receptors include discoidin domain receptors, INTEGRINS, and glycoprotein VI.
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.
Adherence of cells to surfaces or to other cells.
Glycoproteins found on the membrane or surface of cells.
Amidines are organic compounds containing the functional group consisting of a nitrogen atom connected to two carbon atoms by double bonds, with the remaining two bonds attached to hydrogen and any other organic substituent.
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
Coagulation of blood in any of the CORONARY VESSELS. The presence of a blood clot (THROMBUS) often leads to MYOCARDIAL INFARCTION.
Immunoelectrophoresis in which a second electrophoretic transport is performed on the initially separated antigen fragments into an antibody-containing medium in a direction perpendicular to the first electrophoresis.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
The rate dynamics in chemical or physical systems.
The process which spontaneously arrests the flow of BLOOD from vessels carrying blood under pressure. It is accomplished by contraction of the vessels, adhesion and aggregation of formed blood elements (eg. ERYTHROCYTE AGGREGATION), and the process of BLOOD COAGULATION.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
NECROSIS of the MYOCARDIUM caused by an obstruction of the blood supply to the heart (CORONARY CIRCULATION).
Agents that prevent clotting.
A family of related, adhesive glycoproteins which are synthesized, secreted, and incorporated into the extracellular matrix of a variety of cells, including alpha granules of platelets following thrombin activation and endothelial cells. They interact with a number of BLOOD COAGULATION FACTORS and anticoagulant factors. Five distinct forms have been identified, thrombospondin 1, -2, -3, -4, and cartilage oligomeric matrix protein (COMP). They are involved in cell adhesion, platelet aggregation, cell proliferation, angiogenesis, tumor metastasis, VASCULAR SMOOTH MUSCLE growth, and tissue repair.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.
A protein derived from FIBRINOGEN in the presence of THROMBIN, which forms part of the blood clot.
A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.
Precordial pain at rest, which may precede a MYOCARDIAL INFARCTION.
Pyrrolidines are saturated, heterocyclic organic compounds containing a five-membered ring with four carbon atoms and one nitrogen atom (NRCH2CH2), commonly found as structural components in various alkaloids and used in the synthesis of pharmaceuticals and other organic materials.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
A phenomenon in which the surface of a liquid where it contacts a solid is elevated or depressed, because of the relative attraction of the molecules of the liquid for each other and for those of the solid. (from McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Established cell cultures that have the potential to propagate indefinitely.
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).
Proteins which contain carbohydrate groups attached covalently to the polypeptide chain. The protein moiety is the predominant group with the carbohydrate making up only a small percentage of the total weight.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Azoles with an OXYGEN and a NITROGEN next to each other at the 1,2 positions, in contrast to OXAZOLES that have nitrogens at the 1,3 positions.
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.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Local surface sites on antibodies which react with antigen determinant sites on antigens (EPITOPES.) They are formed from parts of the variable regions of FAB FRAGMENTS.
Dilation of an occluded coronary artery (or arteries) by means of a balloon catheter to restore myocardial blood supply.
A dye which inhibits protein biosynthesis at the initial stages. The ammonium salt (aluminon) is a reagent for the colorimetric estimation of aluminum in water, foods, and tissues.
Antibodies that react with self-antigens (AUTOANTIGENS) of the organism that produced them.
The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.
The relationship between the dose of an administered drug and the response of the organism to the drug.
Orosomucoid, also known as alpha-1-acid glycoprotein, is an acute phase protein involved in the immune response, functioning as a pattern recognition receptor and having the ability to bind various ligands including drugs and hormones.
A non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination. It is involved in sugar and acid metabolism, increases IMMUNITY, and provides energy for muscle tissue, BRAIN, and the CENTRAL NERVOUS SYSTEM.
Venoms from SNAKES of the viperid family. They tend to be less toxic than elapid or hydrophid venoms and act mainly on the vascular system, interfering with coagulation and capillary membrane integrity and are highly cytotoxic. They contain large amounts of several enzymes, other factors, and some toxins.
A myelin protein found in the periaxonal membrane of both the central and peripheral nervous systems myelin sheaths. It binds to cells surface receptors found on AXONS and may regulate cellular interactions between MYELIN and AXONS.
Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.
Peptides whose amino and carboxy ends are linked together with a peptide bond forming a circular chain. Some of them are ANTI-INFECTIVE AGENTS. Some of them are biosynthesized non-ribosomally (PEPTIDE BIOSYNTHESIS, NON-RIBOSOMAL).
An integrin found on fibroblasts, platelets, endothelial and epithelial cells, and lymphocytes where it functions as a receptor for COLLAGEN and LAMININ. Although originally referred to as the collagen receptor, it is one of several receptors for collagen. Ligand binding to integrin alpha2beta1 triggers a cascade of intracellular signaling, including activation of p38 MAP kinase.
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.
Physiologically active compounds found in many organs of the body. They are formed in vivo from the prostaglandin endoperoxides and cause platelet aggregation, contraction of arteries, and other biological effects. Thromboxanes are important mediators of the actions of polyunsaturated fatty acids transformed by cyclooxygenase.
An unstable intermediate between the prostaglandin endoperoxides and thromboxane B2. The compound has a bicyclic oxaneoxetane structure. It is a potent inducer of platelet aggregation and causes vasoconstriction. It is the principal component of rabbit aorta contracting substance (RCS).
A characteristic symptom complex.
A family of crosslinking filament proteins encoded by distinct FLN genes. Filamins are involved in cell adhesion, spreading, and migration, acting as scaffolds for over 90 binding partners including channels, receptors, intracellular signaling molecules and transcription factors. Due to the range of molecular interactions, mutations in FLN genes result in anomalies with moderate to lethal consequences.
A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.
The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.
An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
A condition in newborns caused by immunity of the mother to PLATELET ALLOANTIGENS on the fetal platelets. The PLATELETS, coated with maternal ANTIBODIES, are destroyed and removed by the fetal MONONUCLEAR PHAGOCYTE SYSTEM. Affected infants may have INTRACRANIAL HEMORRHAGES.
Elements of limited time intervals, contributing to particular results or situations.
Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.
A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.
A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)
Antigens that exist in alternative (allelic) forms in a single species. When an isoantigen is encountered by species members who lack it, an immune response is induced. Typical isoantigens are the BLOOD GROUP ANTIGENS.
Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.
A genus of venomous snakes of the subfamily Crotalinae. Twelve species of this genus are found in North and Central America and Asia. Agkistrodon contortrix is the copperhead, A. piscivorus, the cottonmouth. The former is named for its russet or orange-brown color, the latter for the white interior of its mouth. (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, p336; Moore, Poisonous Snakes of the World, 1980, p75)
Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.
A large family of signal-transducing adaptor proteins present in wide variety of eukaryotes. They are PHOSPHOSERINE and PHOSPHOTHREONINE binding proteins involved in important cellular processes including SIGNAL TRANSDUCTION; CELL CYCLE control; APOPTOSIS; and cellular stress responses. 14-3-3 proteins function by interacting with other signal-transducing proteins and effecting changes in their enzymatic activity and subcellular localization. The name 14-3-3 derives from numerical designations used in the original fractionation patterns of the proteins.
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 level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
Leukocyte differentiation antigens and major platelet membrane glycoproteins present on MONOCYTES; ENDOTHELIAL CELLS; PLATELETS; and mammary EPITHELIAL CELLS. They play major roles in CELL ADHESION; SIGNAL TRANSDUCTION; and regulation of angiogenesis. CD36 is a receptor for THROMBOSPONDINS and can act as a scavenger receptor that recognizes and transports oxidized LIPOPROTEINS and FATTY ACIDS.
A genus of the subfamily CERCOPITHECINAE, family CERCOPITHECIDAE, consisting of five named species: PAPIO URSINUS (chacma baboon), PAPIO CYNOCEPHALUS (yellow baboon), PAPIO PAPIO (western baboon), PAPIO ANUBIS (or olive baboon), and PAPIO HAMADRYAS (hamadryas baboon). Members of the Papio genus inhabit open woodland, savannahs, grassland, and rocky hill country. Some authors consider MANDRILLUS a subgenus of Papio.
A proteolytic enzyme in the serine protease family found in many tissues which converts PLASMINOGEN to FIBRINOLYSIN. It has fibrin-binding activity and is immunologically different from UROKINASE-TYPE PLASMINOGEN ACTIVATOR. The primary sequence, composed of 527 amino acids, is identical in both the naturally occurring and synthetic proteases.
A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
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.
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.
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.
Agents that cause agglutination of red blood cells. They include antibodies, blood group antigens, lectins, autoimmune factors, bacterial, viral, or parasitic blood agglutinins, etc.
Serologic tests in which a positive reaction manifested by visible CHEMICAL PRECIPITATION occurs when a soluble ANTIGEN reacts with its precipitins, i.e., ANTIBODIES that can form a precipitate.
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 phospholipid from the platelet membrane that contributes to the blood clotting cascade by forming a phospholipid-protein complex (THROMBOPLASTIN) which serves as a cofactor with FACTOR VIIA to activate FACTOR X in the extrinsic pathway of BLOOD COAGULATION.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.
Organic salts or esters of methanesulfonic acid.
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.
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.
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.
Specific cell surface receptors which bind to FIBRONECTINS. Studies have shown that these receptors function in certain types of adhesive contact as well as playing a major role in matrix assembly. These receptors include the traditional fibronectin receptor, also called INTEGRIN ALPHA5BETA1 and several other integrins.
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.
A biochemical messenger and regulator, synthesized from the essential amino acid L-TRYPTOPHAN. In humans it is found primarily in the central nervous system, gastrointestinal tract, and blood platelets. Serotonin mediates several important physiological functions including neurotransmission, gastrointestinal motility, hemostasis, and cardiovascular integrity. Multiple receptor families (RECEPTORS, SEROTONIN) explain the broad physiological actions and distribution of this biochemical mediator.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
Disease having a short and relatively severe course.
Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
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.
An essential branched-chain amino acid important for hemoglobin formation.
Antibodies from an individual that react with ISOANTIGENS of another individual of the same species.
Cell surface molecules on cells of the immune system that specifically bind surface molecules or messenger molecules and trigger changes in the behavior of cells. Although these receptors were first identified in the immune system, many have important functions elsewhere.
A myeloproliferative disorder characterized by neoplastic proliferation of erythroblastic and myeloblastic elements with atypical erythroblasts and myeloblasts in the peripheral blood.
Single-chain polypeptides of about 65 amino acids (7 kDa) from LEECHES that have a neutral hydrophobic N terminus, an acidic hydrophilic C terminus, and a compact, hydrophobic core region. Recombinant hirudins lack tyr-63 sulfation and are referred to as 'desulfato-hirudins'. They form a stable non-covalent complex with ALPHA-THROMBIN, thereby abolishing its ability to cleave FIBRINOGEN.
The alpha chain of pituitary glycoprotein hormones (THYROTROPIN; FOLLICLE STIMULATING HORMONE; LUTEINIZING HORMONE) and the placental CHORIONIC GONADOTROPIN. Within a species, the alpha subunits of these four hormones are identical; the distinct functional characteristics of these glycoprotein hormones are determined by the unique beta subunits. Both subunits, the non-covalently bound heterodimers, are required for full biologic activity.
Sepharose is a brand name for a type of cross-linked agarose gel beads used as a matrix in chromatography and other biochemical procedures, known for their high porosity, mechanical stability, and low non-specific binding, making them suitable for various purification and analytical applications.
The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.
Therapy with two or more separate preparations given for a combined effect.
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 subclass of purinergic P2Y receptors that have a preference for ADP binding and are coupled to GTP-BINDING PROTEIN ALPHA SUBUNIT, GI. The P2Y12 purinergic receptors are found in PLATELETS where they play an important role regulating PLATELET ACTIVATION.
Proteins found in any species of virus.
Proteins which participate in contractile processes. They include MUSCLE PROTEINS as well as those found in other cells and tissues. In the latter, these proteins participate in localized contractile events in the cytoplasm, in motile activity, and in cell aggregation phenomena.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Derivatives of ACETIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxymethane structure.
Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
Condensed areas of cellular material that may be bounded by a membrane.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
Percutaneous transluminal procedure for removing atheromatous plaque from the coronary arteries. Both directional (for removing focal atheromas) and rotational (for removing concentric atheromatous plaque) atherectomy devices have been used.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Disorder characterized by a decrease or lack of platelet dense bodies in which the releasable pool of adenine nucleotides and 5HT are normally stored.
A product of the lysis of plasminogen (profibrinolysin) by PLASMINOGEN activators. It is composed of two polypeptide chains, light (B) and heavy (A), with a molecular weight of 75,000. It is the major proteolytic enzyme involved in blood clot retraction or the lysis of fibrin and quickly inactivated by antiplasmins.
The long-term (minutes to hours) administration of a fluid into the vein through venipuncture, either by letting the fluid flow by gravity or by pumping it.
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
The process of generating thrombocytes (BLOOD PLATELETS) from the pluripotent HEMATOPOIETIC STEM CELLS in the BONE MARROW via the MEGAKARYOCYTES. The humoral factor with thrombopoiesis-stimulating activity is designated THROMBOPOIETIN.
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.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
A humoral factor that stimulates the production of thrombocytes (BLOOD PLATELETS). Thrombopoietin stimulates the proliferation of bone marrow MEGAKARYOCYTES and their release of blood platelets. The process is called THROMBOPOIESIS.
A transmembrane protein present in the MYELIN SHEATH of the CENTRAL NERVOUS SYSTEM. It is one of the main autoantigens implicated in the pathogenesis of MULTIPLE SCLEROSIS.
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.
An adhesion-promoting leukocyte surface membrane heterodimer. The alpha subunit consists of the CD11b ANTIGEN and the beta subunit the CD18 ANTIGEN. The antigen, which is an integrin, functions both as a receptor for complement 3 and in cell-cell and cell-substrate adhesive interactions.
The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)
A calcium-activated enzyme that catalyzes the hydrolysis of ATP to yield AMP and orthophosphate. It can also act on ADP and other nucleoside triphosphates and diphosphates. EC 3.6.1.5.
Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.
A plasma protein that is the inactive precursor of thrombin. It is converted to thrombin by a prothrombin activator complex consisting of factor Xa, factor V, phospholipid, and calcium ions. Deficiency of prothrombin leads to hypoprothrombinemia.
Polysaccharides are complex carbohydrates consisting of long, often branched chains of repeating monosaccharide units joined together by glycosidic bonds, which serve as energy storage molecules (e.g., glycogen), structural components (e.g., cellulose), and molecular recognition sites in various biological systems.
Methods used for studying the interactions of antibodies with specific regions of protein antigens. Important applications of epitope mapping are found within the area of immunochemistry.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.

Primary haemostasis: sticky fingers cement the relationship. (1/1488)

Platelet aggregation to form a haemostatic plug, or thrombus, plays a key role in preventing bleeding from a wound. Recent studies have provided new insights into how platelet receptors are deployed during the interactions with the vascular subendothelial matrix that lead to haemostatic plug formation.  (+info)

Phenotypic and functional evidence for the expression of CXCR4 receptor during megakaryocytopoiesis. (2/1488)

The identification of stromal cell-derived factor (SDF)-1alpha as a chemoattractant for human progenitor cells suggests that this chemokine and its receptor might represent critical determinants for the homing, retention, and exit of precursor cells from hematopoietic organs. In this study, we investigated the expression profile of CXCR4 receptor and the biological activity of SDF-1alpha during megakaryocytopoiesis. CD34(+) cells from bone marrow and cord blood were purified and induced to differentiate toward the megakaryocyte lineage by a combination of stem-cell factor (SCF) and recombinant human pegylated megakaryocyte growth and development factor (PEG-rhuMGDF). After 6 days of culture, a time where mature and immature megakaryocytes were present, CD41(+) cells were immunopurified and CXCR4mRNA expression was studied. High transcript levels were detected by a RNase protection assay in cultured megakaryocytes derived from cord blood CD34(+) cells as well as in peripheral blood platelets. The transcript levels were about equivalent to that found in activated T cells. By flow cytometry, a large fraction (ranging from 30% to 100%) of CD41(+) cells showed high levels of CXCR4 antigen on their surface, its expression increasing in parallel with the CD41 antigen during megakaryocytic differentiation. CXCR4 protein was also detected on peripheral blood platelets. SDF-1alpha acts on megakaryocytes by inducing intracellular calcium mobilization and actin polymerization. In addition, in in vitro transmigration experiments, a significant proportion of megakaryocytes was observed to respond to this chemokine. This cell migration was inhibited by pertussis toxin, indicating coupling of this signal to heterotrimeric guanine nucleotide binding proteins. Although a close correlation between CD41a and CXCR4 expession was observed, cell surface markers as well as morphological criteria indicate a preferential attraction of immature megakaryocytes (low level of CD41a and CD42a), suggesting that SDF-1alpha is a potent attractant for immature megakaryocytic cells but is less active on fully mature megakaryocytes. This hypothesis was further supported by the observation that SDF-1alpha induced the migration of colony forming unit-megakaryocyte progenitors (CFU-MK) and the expression of activation-dependent P-selectin (CD62P) surface antigen on early megakaryocytes, although no effect was observed on mature megakaryocytes and platelets. These results indicate that CXCR4 is expressed by human megakaryocytes and platelets. Furthermore, based on the lower responses of mature megakaryocytes and platelets to SDF-1alpha as compared with early precursors, these data suggest a role for this chemokine in the maintenance and homing during early stages of megakaryocyte development. Moreover, because megakaryocytes are also reported to express CD4, it becomes important to reevaluate the role of direct infection of these cells by the human immunodeficiency virus (HIV)-1 in HIV-1-related thrombocytopenia.  (+info)

Labeling of the internal pool of GP IIb-IIIa in platelets by c7E3 Fab fragments (abciximab): flow and endocytic mechanisms contribute to the transport. (3/1488)

Abciximab is a new antiplatelet therapeutic in ischemic cardiovascular disease. The drug, chimeric Fab fragments of a murine monoclonal antibody (MoAb) (c7E3), blocks GP IIb-IIIa function. However, its capacity to reach all receptor pools in platelets is unknown. Electron microscopy and immunogold labeling were used to localize abciximab in platelets of patients receiving the drug for up to 24 hours. Studies on frozen-thin sections showed that c7E3 Fab, in addition to the surface pool, also labeled the surface-connected canalicular system (SCCS) and alpha-granules. Analysis of gold particle distribution showed that intraplatelet labeling was not accumulative and in equilibrium with the surface pool. After short-term incubations of platelets with c7E3 Fab in vitro, gold particles were often seen in lines within thin elements of the SCCS, some of which appeared in contact with alpha-granules. Little labeling was associated with Glanzmann's thrombasthenia platelets, confirming that the channels contained bound and not free c7E3 Fab. Endocytosis of abciximab in clathrin-containing vesicles was visualized by double staining and constitutes an alternative mechanism of transport. The remaining free pool of GP IIb-IIIa was evaluated with the MoAb AP-2; flow cytometry showed it to be about 9% on the surface of nonstimulated platelets but 33% on thrombin-activated platelets. The ability of drugs to block all pools of GP IIb-IIIa and then to be associated with secretion-dependent residual aggregation must be considered when evaluating their efficiency in a clinical context.  (+info)

Platelet high affinity low density lipoprotein binding and import of lipoprotein derived phospholipids. (4/1488)

The binding of low density lipoprotein (LDL) to the platelet cell membrane could facilitate the transfer of phospholipids from LDL to the platelets. A polyclonal antibody against the platelet glycoproteins IIb/IIIa inhibited the high affinity binding of 125I-LDL by up to 80%. The transfer of pyrene (py)-labeled sphingomyelin (SM), phosphatidylcholine and phosphatidylethanolamine from LDL to the platelets was unaffected by the antibody. The lectin wheat germ agglutinin (WGA) reduced the binding of 125I-LDL to the platelets by approximately 80%. In contrast, the lectin stimulated the transfer of SM from LDL into the platelets by about three-fold. WGA also specifically augmented the transfer of py-SM between lipid vesicles and the platelets, the stimulation being abolished in the presence of N-acetylglucosamine. Dextran sulfate (DS) increased the specific binding of 125I-LDL to the platelets by up to 2.8-fold. On the other hand, the import of LDL-derived py-phospholipids was unaffected by DS. Together, the results indicate that the phospholipid transfer from LDL to the platelets is independent of the high affinity LDL binding to the platelets and is specifically stimulated by WGA. Thus, the interactions of platelets with LDL phospholipids differ markedly from those with the apoprotein components of the lipoproteins.  (+info)

PlA polymorphism of platelet glycoprotein IIIa and risk of restenosis after coronary stent placement. (5/1488)

BACKGROUND: Platelets play a central role in the process of restenosis after percutaneous coronary interventions. A polymorphism of platelet glycoprotein IIIa (PlA) has been associated with a higher risk of coronary thrombosis. We designed this prospective study to test the hypothesis that PlA polymorphism of glycoprotein IIIa is associated with an increased risk for restenosis after coronary stent placement. METHODS AND RESULTS: The study included 1150 consecutive patients with successful coronary stent placement and 6-month follow-up with coronary angiography. The end point of the study was the incidence of angiographic restenosis (>/=50% diameter stenosis) at follow-up. Of the 1150 patients, 72.5% were homozygous for PlA1, 24.7% were heterozygous (PlA1/A2), and 2.8% were homozygous for PlA2. Patients with the PlA2 allele demonstrated a significantly higher restenosis rate than did those without (47% versus 38%; OR, 1.42; 95% CI, 1.09 to 1.84). The risk was highest in homozygous carriers of PlA2 (53.1% restenosis rate). After adjustment for several clinical and angiographic characteristics, the presence of the PlA2 allele remained a significantly independent risk factor for restenosis (adjusted OR, 1.35; 95% CI, 1.07 to 1.70). The influence of the PlA2 allele on restenosis was stronger in women. Women with PlA2 had a restenosis rate of 52% compared with the 33% incidence among women homozygous for PlA1 (OR, 2.21; 95% CI, 1.27 to 3.85). CONCLUSIONS: This study showed a significant association between the PlA polymorphism of glycoprotein IIIa and the risk of restenosis after coronary stent placement. The risk was more pronounced in patients homozygous for PlA2 allele and in female patients.  (+info)

Influence of monoclonal antiplatelet glycoprotein antibodies on in vitro human megakaryocyte colony formation and proplatelet formation. (6/1488)

The influence of antiplatelet glycoprotein (GP) antibodies on megakaryocytopoiesis in patients with idiopathic or immune thrombocytopenic purpura (ITP) has been well studied. However, the influence of GP antibodies on proplatelet formation is poorly understood. Here we investigated whether in vitro human megakaryocyte colony formation and proplatelet formation are affected by various monoclonal antiplatelet GP antibodies (MoAb). The megakaryocyte colony formation inhibition assay was performed by methylcellulose culture with modifications, using peripheral blood nonadherent mononuclear cells. The proplatelet formation inhibition assay was performed by megakaryocytes derived from CD34(+) cells, stimulated with thrombopoietin + stem cell factor, which were then incubated with antiplatelet GP MoAb for 24 or 48 hours. Anti-GP-Ibalpha MoAb (CD42b; HIP1) slightly inhibited megakaryocyte colony formation (P < .05). and strongly inhibited proplatelet formation (after 24 hours incubation, P < .0002; after 48 hours incubation, P < .0007). Anti-GP-IIb MoAb (CD41; 5B12) inhibited only proplatelet formation (only after 24 hours incubation, P <. 03). Anti-integrin alphavbeta3 MoAb (CD51/CD61; 23C6) only slightly inhibited colony size (P < .05). However, anti-GP-IIIa MoAb (CD61; Y2/51) did not inhibit either colony formation or proplatelet formation. These results suggest that antiplatelet GP MoAbs have differing effects on in vitro megakaryocyte colony formation and proplatelet formation.  (+info)

Increased serotonin receptor density and platelet GPIIb/IIIa activation among smokers. (7/1488)

This study sought to determine whether depressive symptoms and/or platelet serotonin receptor (5HT2A) density are associated with increased platelet activation (PA) found among smokers. Flow cytometric detection of PA was used to study 36 smokers and 16 nonsmokers, aged 18 to 48 years. Subjects were tested at baseline and after either smoking 2 cigarettes (smokers) or a similar resting interval (nonsmokers). Assessment of PA included both platelet secretion and fibrinogen receptor (GPIIb/IIIa) binding. Platelet 5HT2A receptor binding and saturation were tested using [3H]LSD, and depressive symptoms were measured using the Beck Depression Inventory. Platelet 5HT2A receptor density was increased among smokers versus nonsmokers (82.7+/-67.7 versus 40.0+/-20.2 fmol/mg protein; P<0.005), and there was a dose-dependent relationship between receptor density and packs/d among smokers. Baseline wound-induced GPIIb/IIIa binding at 1 minute and GPIIb/IIIa binding in response to collagen stimulation in vitro was increased among smokers (P<0.05); there were no changes in PA among smokers after smoking, and platelet secretion was not elevated among smokers. Depressive symptoms were associated with 5HT2A receptor density among nonsmokers (P<0.005), but no such relationship was evident among smokers; PA was unrelated to 5HT2A receptor density in either group. The findings indicate that smoking is associated with increased platelet serotonin receptor density and with increased GPIIb/IIIa receptor binding, although these 2 factors are not related to each other or to depressive symptoms among smokers. Serotonergic dysfunction may be an important factor in the development of cardiovascular disease among smokers.  (+info)

A model for studying megakaryocyte development and biology. (8/1488)

The limited current understanding of megakaryocyte-lineage development and megakaryocyte biology is in large part because of a paucity of useful systems in which to conduct experiments. To overcome this problem, we have developed a transgenic mouse that uses the GP-Ibalpha regulatory sequences to achieve megakaryocyte-lineage restricted expression of an avian retroviral receptor. Through the transgenic avian receptor, avian retroviruses can efficiently and selectively infect megakaryocyte-lineage cells in vitro and in vivo. Serial infections can be performed to introduce and express multiple genes in the same cell. We have used this system to generate and characterize a pure population of primary CD41-positive megakaryocyte progenitors.  (+info)

Platelet membrane glycoproteins are specialized proteins found on the surface of platelets, which are small blood cells responsible for clotting. These glycoproteins play crucial roles in various processes related to hemostasis and thrombosis, including platelet adhesion, activation, and aggregation.

There are several key platelet membrane glycoproteins, such as:

1. Glycoprotein (GP) Ia/IIa (also known as integrin α2β1): This glycoprotein mediates the binding of platelets to collagen fibers in the extracellular matrix, facilitating platelet adhesion and activation.
2. GP IIb/IIIa (also known as integrin αIIbβ3): This is the most abundant glycoprotein on the platelet surface and functions as a receptor for fibrinogen, von Willebrand factor, and other adhesive proteins. Upon activation, GP IIb/IIIa undergoes conformational changes that enable it to bind these ligands, leading to platelet aggregation and clot formation.
3. GPIb-IX-V: This glycoprotein complex is involved in the initial tethering and adhesion of platelets to von Willebrand factor (vWF) in damaged blood vessels. It consists of four subunits: GPIbα, GPIbβ, GPIX, and GPV.
4. GPVI: This glycoprotein is essential for platelet activation upon contact with collagen. It associates with the Fc receptor γ-chain (FcRγ) to form a signaling complex that triggers intracellular signaling pathways, leading to platelet activation and aggregation.

Abnormalities in these platelet membrane glycoproteins can lead to bleeding disorders or thrombotic conditions. For example, mutations in GPIIb/IIIa can result in Glanzmann's thrombasthenia, a severe bleeding disorder characterized by impaired platelet aggregation. On the other hand, increased expression or activation of these glycoproteins may contribute to the development of arterial thrombosis and cardiovascular diseases.

Thrombasthenia is a rare bleeding disorder that is inherited and caused by a deficiency or dysfunction of the platelet glycoprotein IIb/IIIa complex. This complex plays a crucial role in platelet aggregation, which is necessary for blood clotting. When it's defective or absent, platelets are unable to aggregate properly, leading to prolonged bleeding times and symptoms such as easy bruising, nosebleeds, and excessive bleeding following injury or surgery. There are two main types of thrombasthenia: Glanzmann's thrombasthenia and pseudo-thrombasthenia.

Blood platelets, also known as thrombocytes, are small, colorless cell fragments in our blood that play an essential role in normal blood clotting. They are formed in the bone marrow from large cells called megakaryocytes and circulate in the blood in an inactive state until they are needed to help stop bleeding. When a blood vessel is damaged, platelets become activated and change shape, releasing chemicals that attract more platelets to the site of injury. These activated platelets then stick together to form a plug, or clot, that seals the wound and prevents further blood loss. In addition to their role in clotting, platelets also help to promote healing by releasing growth factors that stimulate the growth of new tissue.

Platelet aggregation is the clumping together of platelets (thrombocytes) in the blood, which is an essential step in the process of hemostasis (the stopping of bleeding) after injury to a blood vessel. When the inner lining of a blood vessel is damaged, exposure of subendothelial collagen and tissue factor triggers platelet activation. Activated platelets change shape, become sticky, and release the contents of their granules, which include ADP (adenosine diphosphate).

ADP then acts as a chemical mediator to attract and bind additional platelets to the site of injury, leading to platelet aggregation. This forms a plug that seals the damaged vessel and prevents further blood loss. Platelet aggregation is also a crucial component in the formation of blood clots (thrombosis) within blood vessels, which can have pathological consequences such as heart attacks and strokes if they obstruct blood flow to vital organs.

The platelet glycoprotein GPIIb-IIIa complex, also known as integrin αIIbβ3 or CD41/CD61, is a heterodimeric transmembrane receptor found on the surface of platelets and megakaryocytes. It plays a crucial role in platelet aggregation and thrombus formation during hemostasis and pathological conditions such as arterial thrombosis.

The GPIIb-IIIa complex is composed of two non-covalently associated subunits, GPIIb (αIIb or CD41) and IIIa (β3 or CD61). Upon platelet activation by various agonists like ADP, thrombin, or collagen, the GPIIb-IIIa complex undergoes a conformational change that allows it to bind fibrinogen, von Willebrand factor, and other adhesive proteins. This binding event leads to platelet aggregation and the formation of a hemostatic plug or pathological thrombus.

Inhibition of the GPIIb-IIIa complex has been a target for antiplatelet therapy in the prevention and treatment of arterial thrombosis, such as myocardial infarction and stroke. Several pharmacological agents, including monoclonal antibodies and small molecule antagonists, have been developed to block this complex and reduce platelet aggregation.

The platelet glycoprotein GPIb-IX complex is a crucial receptor on the surface of platelets that plays a vital role in hemostasis and thrombosis. It is a heterotetrameric transmembrane protein complex composed of two disulfide-linked glycoprotein subunits, GPIbα, GPIbβ, GPV (Glycoprotein V), and GPIX (Glycoprotein IX).

The GPIb-IX complex is responsible for the initial interaction between platelets and von Willebrand factor (vWF) in the circulation. When blood vessels are damaged, exposed collagen recruits vWF to the site of injury, where it binds to the GPIbα subunit of the GPIb-IX complex, leading to platelet adhesion and activation. This interaction is critical for primary hemostasis, which helps prevent excessive blood loss from injured vessels.

Genetic mutations or deficiencies in the genes encoding these glycoproteins can lead to bleeding disorders such as Bernard-Soulier syndrome, a rare autosomal recessive disorder characterized by thrombocytopenia and large platelets with impaired vWF binding and platelet adhesion.

Fibrinogen is a soluble protein present in plasma, synthesized by the liver. It plays an essential role in blood coagulation. When an injury occurs, fibrinogen gets converted into insoluble fibrin by the action of thrombin, forming a fibrin clot that helps to stop bleeding from the injured site. Therefore, fibrinogen is crucial for hemostasis, which is the process of stopping bleeding and starting the healing process after an injury.

Von Willebrand factor (vWF) is a large multimeric glycoprotein that plays a crucial role in hemostasis, the process which leads to the cessation of bleeding and the formation of a blood clot. It was named after Erik Adolf von Willebrand, a Finnish physician who first described the disorder associated with its deficiency, known as von Willebrand disease (vWD).

The primary functions of vWF include:

1. Platelet adhesion and aggregation: vWF mediates the initial attachment of platelets to damaged blood vessel walls by binding to exposed collagen fibers and then interacting with glycoprotein Ib (GPIb) receptors on the surface of platelets, facilitating platelet adhesion. Subsequently, vWF also promotes platelet-platelet interactions (aggregation) through its interaction with platelet glycoprotein IIb/IIIa (GPIIb/IIIa) receptors under high shear stress conditions found in areas of turbulent blood flow, such as arterioles and the capillary bed.

2. Transport and stabilization of coagulation factor VIII: vWF serves as a carrier protein for coagulation factor VIII (FVIII), protecting it from proteolytic degradation and maintaining its stability in circulation. This interaction between vWF and FVIII is essential for the proper functioning of the coagulation cascade, particularly in the context of vWD, where impaired FVIII function can lead to bleeding disorders.

3. Wound healing: vWF contributes to wound healing by promoting platelet adhesion and aggregation at the site of injury, which facilitates the formation of a provisional fibrin-based clot that serves as a scaffold for tissue repair and regeneration.

In summary, von Willebrand factor is a vital hemostatic protein involved in platelet adhesion, aggregation, coagulation factor VIII stabilization, and wound healing. Deficiencies or dysfunctions in vWF can lead to bleeding disorders such as von Willebrand disease.

Platelet adhesiveness refers to the ability of platelets, which are small blood cells that help your body form clots to prevent excessive bleeding, to stick to other cells or surfaces. This process is crucial in hemostasis, the process of stopping bleeding after injury to a blood vessel.

When the endothelium (the lining of blood vessels) is damaged, subendothelial structures are exposed, which can trigger platelet adhesion. Platelets then change shape and release chemical signals that cause other platelets to clump together, forming a platelet plug. This plug helps to seal the damaged vessel and prevent further bleeding.

Platelet adhesiveness is influenced by several factors, including the presence of von Willebrand factor (vWF), a protein in the blood that helps platelets bind to damaged vessels, and the expression of glycoprotein receptors on the surface of platelets. Abnormalities in platelet adhesiveness can lead to bleeding disorders or thrombotic conditions.

Human platelet antigens (HPAs) are a group of cell surface proteins found on platelets and megakaryocytes, which are the precursor cells that produce platelets. These antigens can stimulate an immune response when they are recognized as foreign by the body's immune system, leading to the production of antibodies against them.

HPAs are classified into several different systems based on their genetic inheritance and immunological properties. The most well-known HPA systems are HPA-1, HPA-2, HPA-3, HPA-4, and HPA-5. Each system consists of a pair of alleles, one inherited from each parent, that code for different variants of the antigen.

HPAs can play a role in the development of certain bleeding disorders, such as neonatal alloimmune thrombocytopenia (NAIT) and post-transfusion purpura (PTP). NAIT occurs when a pregnant woman develops antibodies against her fetus's HPAs, leading to low platelet counts and bleeding in the newborn. PTP can occur after a transfusion of blood products containing HPAs that are not compatible with the recipient's HPAs, leading to an immune response and destruction of the transfused platelets.

It is important for healthcare providers to consider HPA compatibility when performing platelet transfusions or managing pregnant women at risk of developing antibodies against HPAs.

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.

Platelet aggregation inhibitors are a class of medications that prevent platelets (small blood cells involved in clotting) from sticking together and forming a clot. These drugs work by interfering with the ability of platelets to adhere to each other and to the damaged vessel wall, thereby reducing the risk of thrombosis (blood clot formation).

Platelet aggregation inhibitors are often prescribed for people who have an increased risk of developing blood clots due to various medical conditions such as atrial fibrillation, coronary artery disease, peripheral artery disease, stroke, or a history of heart attack. They may also be used in patients undergoing certain medical procedures, such as angioplasty and stenting, to prevent blood clot formation in the stents.

Examples of platelet aggregation inhibitors include:

1. Aspirin: A nonsteroidal anti-inflammatory drug (NSAID) that irreversibly inhibits the enzyme cyclooxygenase, which is involved in platelet activation and aggregation.
2. Clopidogrel (Plavix): A P2Y12 receptor antagonist that selectively blocks ADP-induced platelet activation and aggregation.
3. Prasugrel (Effient): A third-generation thienopyridine P2Y12 receptor antagonist, similar to clopidogrel but with faster onset and greater potency.
4. Ticagrelor (Brilinta): A direct-acting P2Y12 receptor antagonist that does not require metabolic activation and has a reversible binding profile.
5. Dipyridamole (Persantine): An antiplatelet agent that inhibits platelet aggregation by increasing cyclic adenosine monophosphate (cAMP) levels in platelets, which leads to decreased platelet reactivity.
6. Iloprost (Ventavis): A prostacyclin analogue that inhibits platelet aggregation and causes vasodilation, often used in the treatment of pulmonary arterial hypertension.
7. Cilostazol (Pletal): A phosphodiesterase III inhibitor that increases cAMP levels in platelets, leading to decreased platelet activation and aggregation, as well as vasodilation.
8. Ticlopidine (Ticlid): An older P2Y12 receptor antagonist with a slower onset of action and more frequent side effects compared to clopidogrel or prasugrel.

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

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

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

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

Thrombin is a serine protease enzyme that plays a crucial role in the coagulation cascade, which is a complex series of biochemical reactions that leads to the formation of a blood clot (thrombus) to prevent excessive bleeding during an injury. Thrombin is formed from its precursor protein, prothrombin, through a process called activation, which involves cleavage by another enzyme called factor Xa.

Once activated, thrombin converts fibrinogen, a soluble plasma protein, into fibrin, an insoluble protein that forms the structural framework of a blood clot. Thrombin also activates other components of the coagulation cascade, such as factor XIII, which crosslinks and stabilizes the fibrin network, and platelets, which contribute to the formation and growth of the clot.

Thrombin has several regulatory mechanisms that control its activity, including feedback inhibition by antithrombin III, a plasma protein that inactivates thrombin and other serine proteases, and tissue factor pathway inhibitor (TFPI), which inhibits the activation of factor Xa, thereby preventing further thrombin formation.

Overall, thrombin is an essential enzyme in hemostasis, the process that maintains the balance between bleeding and clotting in the body. However, excessive or uncontrolled thrombin activity can lead to pathological conditions such as thrombosis, atherosclerosis, and disseminated intravascular coagulation (DIC).

Ristocetin is not a medical condition but a type of antibiotic used to treat infections caused by certain Gram-positive bacteria that are resistant to other antibiotics. Ristocetin is an glycopeptide antibiotic, which works by binding to the bacterial cell wall and inhibiting its synthesis, leading to bacterial death. It is not commonly used due to its potential to cause blood disorders, such as thrombocytopenia (low platelet count) and platelet aggregation.

In medical literature, ristocetin is also known for its use in the laboratory setting as a reagent for the platelet function test, called the ristocetin-induced platelet aggregation (RIPA) assay. This test is used to evaluate the ability of platelets to aggregate and form clots in response to ristocetin, which can help diagnose certain bleeding disorders such as Bernard-Soulier syndrome and von Willebrand disease.

A platelet count is a laboratory test that measures the number of platelets, also known as thrombocytes, in a sample of blood. Platelets are small, colorless cell fragments that circulate in the blood and play a crucial role in blood clotting. They help to stop bleeding by sticking together to form a plug at the site of an injured blood vessel.

A normal platelet count ranges from 150,000 to 450,000 platelets per microliter (µL) of blood. A lower than normal platelet count is called thrombocytopenia, while a higher than normal platelet count is known as thrombocytosis.

Abnormal platelet counts can be a sign of various medical conditions, including bleeding disorders, infections, certain medications, and some types of cancer. It is important to consult with a healthcare provider if you have any concerns about your platelet count or if you experience symptoms such as easy bruising, prolonged bleeding, or excessive menstrual flow.

Adenosine diphosphate (ADP) is a chemical compound that plays a crucial role in energy transfer within cells. It is a nucleotide, which consists of a adenosine molecule (a sugar molecule called ribose attached to a nitrogenous base called adenine) and two phosphate groups.

In the cell, ADP functions as an intermediate in the conversion of energy from one form to another. When a high-energy phosphate bond in ADP is broken, energy is released and ADP is converted to adenosine triphosphate (ATP), which serves as the main energy currency of the cell. Conversely, when ATP donates a phosphate group to another molecule, it is converted back to ADP, releasing energy for the cell to use.

ADP also plays a role in blood clotting and other physiological processes. In the coagulation cascade, ADP released from damaged red blood cells can help activate platelets and initiate the formation of a blood clot.

Bleeding time is a medical test that measures the time it takes for a small blood vessel to stop bleeding after being cut. It's used to evaluate platelet function and the effectiveness of blood clotting. The most common method used to measure bleeding time is the Ivy method, which involves making a standardized incision on the forearm and measuring the time it takes for the bleeding to stop. A normal bleeding time ranges from 2 to 9 minutes, but this can vary depending on the specific method used. Prolonged bleeding time may indicate an impairment in platelet function or clotting factor deficiency.

Thrombocytopenia is a medical condition characterized by an abnormally low platelet count (thrombocytes) in the blood. Platelets are small cell fragments that play a crucial role in blood clotting, helping to stop bleeding when a blood vessel is damaged. A healthy adult typically has a platelet count between 150,000 and 450,000 platelets per microliter of blood. Thrombocytopenia is usually diagnosed when the platelet count falls below 150,000 platelets/µL.

Thrombocytopenia can be classified into three main categories based on its underlying cause:

1. Immune thrombocytopenia (ITP): An autoimmune disorder where the immune system mistakenly attacks and destroys its own platelets, leading to a decreased platelet count. ITP can be further divided into primary or secondary forms, depending on whether it occurs alone or as a result of another medical condition or medication.
2. Decreased production: Thrombocytopenia can occur when there is insufficient production of platelets in the bone marrow due to various causes, such as viral infections, chemotherapy, radiation therapy, leukemia, aplastic anemia, or vitamin B12 or folate deficiency.
3. Increased destruction or consumption: Thrombocytopenia can also result from increased platelet destruction or consumption due to conditions like disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS), or severe bacterial infections.

Symptoms of thrombocytopenia may include easy bruising, prolonged bleeding from cuts, spontaneous nosebleeds, bleeding gums, blood in urine or stools, and skin rashes like petechiae (small red or purple spots) or purpura (larger patches). The severity of symptoms can vary depending on the degree of thrombocytopenia and the presence of any underlying conditions. Treatment for thrombocytopenia depends on the cause and may include medications, transfusions, or addressing the underlying condition.

Platelet activation is the process by which platelets (also known as thrombocytes) become biologically active and change from their inactive discoid shape to a spherical shape with pseudopodia, resulting in the release of chemical mediators that are involved in hemostasis and thrombosis. This process is initiated by various stimuli such as exposure to subendothelial collagen, von Willebrand factor, or thrombin during vascular injury, leading to platelet aggregation and the formation of a platelet plug to stop bleeding. Platelet activation also plays a role in inflammation, immune response, and wound healing.

Crotalid venoms are the toxic secretions produced by the members of the Crotalinae subfamily, also known as pit vipers. This group includes rattlesnakes, cottonmouths (or water moccasins), and copperheads, which are native to the Americas, as well as Old World vipers found in Asia and Europe, such as gaboon vipers and saw-scaled vipers.

Crotalid venoms are complex mixtures of various bioactive molecules, including enzymes, proteins, peptides, and other low molecular weight components. They typically contain a variety of pharmacologically active components, such as hemotoxic and neurotoxic agents, which can cause extensive local tissue damage, coagulopathy, cardiovascular dysfunction, and neuromuscular disorders in the victim.

The composition of crotalid venoms can vary significantly between different species and even among individual specimens within the same species. This variability is influenced by factors such as geographic location, age, sex, diet, and environmental conditions. As a result, the clinical manifestations of crotalid envenomation can be highly variable, ranging from mild local reactions to severe systemic effects that may require intensive medical treatment and supportive care.

Crotalid venoms have been the subject of extensive research in recent years due to their potential therapeutic applications. For example, certain components of crotalid venoms have shown promise as drugs for treating various medical conditions, such as cardiovascular diseases, pain, and inflammation. However, further studies are needed to fully understand the mechanisms of action of these venom components and to develop safe and effective therapies based on them.

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.

Glycoprotein IIb (also known as integrin αIIbβ3 or CD41/CD61) is a type of protein found on the surface of platelets, which are small cell fragments involved in blood clotting. This glycoprotein plays a crucial role in the final pathway of platelet activation and aggregation, which ultimately leads to the formation of a clot to stop bleeding.

More specifically, Glycoprotein IIb is responsible for binding fibrinogen, von Willebrand factor, and other adhesive proteins in the blood, allowing platelets to bind together and form a clot. Mutations or defects in this glycoprotein can lead to bleeding disorders such as Glanzmann thrombasthenia, which is characterized by abnormal platelet function and excessive bleeding.

Megakaryocytes are large, specialized bone marrow cells that are responsible for the production and release of platelets (also known as thrombocytes) into the bloodstream. Platelets play an essential role in blood clotting and hemostasis, helping to prevent excessive bleeding during injuries or trauma.

Megakaryocytes have a unique structure with multilobed nuclei and abundant cytoplasm rich in organelles called alpha-granules and dense granules, which store various proteins, growth factors, and enzymes necessary for platelet function. As megakaryocytes mature, they extend long cytoplasmic processes called proplatelets into the bone marrow sinuses, where these extensions fragment into individual platelets that are released into circulation.

Abnormalities in megakaryocyte number, size, or function can lead to various hematological disorders, such as thrombocytopenia (low platelet count), thrombocytosis (high platelet count), and certain types of leukemia.

Bernard-Soulier Syndrome is a rare autosomal recessive bleeding disorder characterized by a deficiency or dysfunction of the glycoprotein Ib-IX-V complex, which is a crucial component of platelet function. This complex plays a role in the initial adhesion of platelets to the damaged endothelium at the site of blood vessel injury.

The deficiency or dysfunction of this complex leads to abnormalities in platelet aggregation and results in prolonged bleeding times, increased bruising, and excessive blood loss during menstruation, surgery, or trauma. Additionally, individuals with Bernard-Soulier Syndrome often have giant platelets and a decreased platelet count (thrombocytopenia).

The syndrome is named after Jean J. Bernard and Jean-Pierre Soulier, who first described the disorder in 1948. It has an estimated prevalence of about 1 in one million individuals worldwide.

Thrombosis is the formation of a blood clot (thrombus) inside a blood vessel, obstructing the flow of blood through the circulatory system. When a clot forms in an artery, it can cut off the supply of oxygen and nutrients to the tissues served by that artery, leading to damage or tissue death. If a thrombus forms in the heart, it can cause a heart attack. If a thrombus breaks off and travels through the bloodstream, it can lodge in a smaller vessel, causing blockage and potentially leading to damage in the organ that the vessel supplies. This is known as an embolism.

Thrombosis can occur due to various factors such as injury to the blood vessel wall, abnormalities in blood flow, or changes in the composition of the blood. Certain medical conditions, medications, and lifestyle factors can increase the risk of thrombosis. Treatment typically involves anticoagulant or thrombolytic therapy to dissolve or prevent further growth of the clot, as well as addressing any underlying causes.

Integrin alpha2, also known as CD49b or ITGA2, is a type I transmembrane glycoprotein that forms a heterodimer with integrin beta1 to create the collagen receptor very late antigen-2 (VLA-2) or α2β1 integrin. This integrin plays crucial roles in various cellular processes such as adhesion, migration, and signaling during embryonic development, hemostasis, and tissue repair. It specifically binds to collagen types I, II, and IV, contributing to the regulation of cell-matrix interactions in several tissues, including bone, cartilage, and vascular systems. Integrin alpha2 also participates in immune responses by mediating lymphocyte adhesion and activation.

Benzamidines are a group of organic compounds that contain a benzene ring linked to an amidine functional group. They are commonly used as antimicrobial agents, particularly in the treatment of various gram-negative bacterial infections. Benzamidines work by inhibiting the enzyme bacterial dehydrogenases, which are essential for the bacteria's survival.

Some examples of benzamidine derivatives include:

* Tempanamine hydrochloride (Tembaglanil): used to treat urinary tract infections caused by susceptible strains of Escherichia coli and Klebsiella pneumoniae.
* Chlorhexidine: a broad-spectrum antimicrobial agent used as a disinfectant and preservative in various medical and dental applications.
* Prothiobenzamide: an anti-inflammatory and analgesic drug used to treat gout and rheumatoid arthritis.

It is important to note that benzamidines have a narrow therapeutic index, which means that the difference between an effective dose and a toxic dose is small. Therefore, they should be used with caution and under the supervision of a healthcare professional.

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.

Integrin β3 is a subunit of certain integrin heterodimers, which are transmembrane receptors that mediate cell-cell and cell-extracellular matrix (ECM) adhesion. Integrin β3 combines with either integrin αv (to form the integrin αvβ3) or integrin αIIb (to form the integrin αIIbβ3). These integrins are involved in various cellular processes, including platelet aggregation, angiogenesis, and tumor metastasis.

Integrin αIIbβ3 is primarily expressed on platelets and mediates platelet aggregation by binding to fibrinogen, von Willebrand factor, and other adhesive proteins in the ECM. Integrin αvβ3 is widely expressed in various cell types and participates in diverse functions such as cell migration, proliferation, differentiation, and survival. It binds to a variety of ECM proteins, including fibronectin, vitronectin, and osteopontin, as well as to soluble ligands like vascular endothelial growth factor (VEGF) and transforming growth factor-β (TGF-β).

Dysregulation of integrin β3 has been implicated in several pathological conditions, such as thrombosis, atherosclerosis, tumor metastasis, and inflammatory diseases.

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.

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

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

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

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

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

P-Selectin is a type of cell adhesion molecule, specifically a member of the selectin family, that is involved in the inflammatory response. It is primarily expressed on the surface of activated platelets and endothelial cells. P-Selectin plays a crucial role in the initial interaction between leukocytes (white blood cells) and the vascular endothelium, which is an essential step in the recruitment of leukocytes to sites of inflammation or injury. This process helps to mediate the rolling and adhesion of leukocytes to the endothelial surface, facilitating their extravasation into the surrounding tissue. P-Selectin's function is regulated by its interaction with specific ligands on the surface of leukocytes, such as PSGL-1 (P-Selectin Glycoprotein Ligand-1).

Platelet Factor 4 (PF4), also known as CXCL4, is a chemokine that is primarily secreted by activated platelets and involved in hemostasis and inflammation. It is a small protein with a molecular weight of approximately 8 kDa and is stored in the alpha granules of resting platelets. Upon activation, platelets release PF4 into the bloodstream, where it plays a role in attracting immune cells to sites of injury or infection.

PF4 can bind to various negatively charged molecules, including heparin, DNA, and RNA, which can lead to the formation of immune complexes. In some cases, these immune complexes can trigger an abnormal immune response, resulting in conditions such as heparin-induced thrombocytopenia (HIT) or vaccine-induced immune thrombotic thrombocytopenia (VITT).

In summary, Platelet Factor 4 is a chemokine released by activated platelets that plays a role in hemostasis and inflammation but can also contribute to the development of certain immune-related disorders.

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.

Platelet function tests are laboratory tests that measure how well platelets, which are small blood cells responsible for clotting, function in preventing or stopping bleeding. These tests are often used to investigate the cause of abnormal bleeding or bruising, or to monitor the effectiveness of antiplatelet therapy in patients with certain medical conditions such as heart disease or stroke.

There are several types of platelet function tests available, including:

1. Platelet count: This test measures the number of platelets present in a sample of blood. A low platelet count can increase the risk of bleeding.
2. Bleeding time: This test measures how long it takes for a small cut to stop bleeding. It is used less frequently than other tests due to its invasiveness and variability.
3. Platelet aggregation tests: These tests measure how well platelets clump together (aggregate) in response to various agents that promote platelet activation, such as adenosine diphosphate (ADP), collagen, or epinephrine.
4. Platelet function analyzer (PFA): This test measures the time it takes for a blood sample to clot under shear stress, simulating the conditions in an injured blood vessel. The PFA can provide information about the overall platelet function and the effectiveness of antiplatelet therapy.
5. Thromboelastography (TEG) or rotational thromboelastometry (ROTEM): These tests measure the kinetics of clot formation, strength, and dissolution in whole blood samples. They provide information about both platelet function and coagulation factors.

These tests can help healthcare providers diagnose bleeding disorders, assess the risk of bleeding during surgery or other invasive procedures, monitor antiplatelet therapy, and guide treatment decisions for patients with abnormal platelet function.

Aspirin is the common name for acetylsalicylic acid, which is a medication used to relieve pain, reduce inflammation, and lower fever. It works by inhibiting the activity of an enzyme called cyclooxygenase (COX), which is involved in the production of prostaglandins, hormone-like substances that cause inflammation and pain. Aspirin also has an antiplatelet effect, which means it can help prevent blood clots from forming. This makes it useful for preventing heart attacks and strokes.

Aspirin is available over-the-counter in various forms, including tablets, capsules, and chewable tablets. It is also available in prescription strengths for certain medical conditions. As with any medication, aspirin should be taken as directed by a healthcare provider, and its use should be avoided in children and teenagers with viral infections due to the risk of Reye's syndrome, a rare but serious condition that can affect the liver and brain.

Oligopeptides are defined in medicine and biochemistry as short chains of amino acids, typically containing fewer than 20 amino acid residues. These small peptides are important components in various biological processes, such as serving as signaling molecules, enzyme inhibitors, or structural elements in some proteins. They can be found naturally in foods and may also be synthesized for use in medical research and therapeutic applications.

Idiopathic Thrombocytopenic Purpura (ITP) is a medical condition characterized by a low platelet count (thrombocytopenia) in the blood without an identifiable cause. Platelets are small blood cells that help your body form clots to stop bleeding. When you don't have enough platelets, you may bleed excessively or spontaneously, causing purpura, which refers to purple-colored spots on the skin that result from bleeding under the skin.

In ITP, the immune system mistakenly attacks and destroys platelets, leading to their decreased levels in the blood. This condition can occur at any age but is more common in children following a viral infection, and in adults after the age of 30-40 years. Symptoms may include easy or excessive bruising, prolonged bleeding from cuts, spontaneous bleeding from the gums or nose, blood blisters, and small red or purple spots on the skin (petechiae).

Depending on the severity of thrombocytopenia and the presence of bleeding symptoms, ITP treatment may include observation, corticosteroids, intravenous immunoglobulin (IVIG), or other medications that modify the immune system's response. In severe cases or when other treatments are ineffective, surgical removal of the spleen (splenectomy) might be considered.

A platelet transfusion is the process of medically administering platelets, which are small blood cells that help your body form clots to stop bleeding. Platelet transfusions are often given to patients with low platelet counts or dysfunctional platelets due to various reasons such as chemotherapy, bone marrow transplantation, disseminated intravascular coagulation (DIC), and other medical conditions leading to increased consumption or destruction of platelets. This procedure helps to prevent or treat bleeding complications in these patients. It's important to note that platelet transfusions should be given under the supervision of a healthcare professional, taking into account the patient's clinical condition, platelet count, and potential risks associated with transfusion reactions.

Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.

Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.

Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.

Dual specificity phosphatase 2 (DUSP2) is a type of enzyme that belongs to the dual specificity phosphatase family. This enzyme is also known as VHR (Vaccinia H1-related phosphatase) and plays a crucial role in regulating various cellular processes, including signal transduction pathways, by removing phosphate groups from both tyrosine and serine/threonine residues of proteins. DUSP2 is primarily located in the nucleus and has been shown to dephosphorylate and negatively regulate mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK) and p38 MAPK, which are involved in cell growth, differentiation, and stress responses. Dysregulation of DUSP2 has been implicated in several pathological conditions, including cancer and neurological disorders.

Fibrinolytic agents are medications that dissolve or break down blood clots by activating plasminogen, which is converted into plasmin. Plasmin is a proteolytic enzyme that degrades fibrin, the structural protein in blood clots. Fibrinolytic agents are used medically to treat conditions such as acute ischemic stroke, deep vein thrombosis, pulmonary embolism, and myocardial infarction (heart attack) by restoring blood flow in occluded vessels. Examples of fibrinolytic agents include alteplase, reteplase, and tenecteplase. It is important to note that these medications carry a risk of bleeding complications and should be administered with caution.

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

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

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

Collagen is the most abundant protein in the human body, and it is a major component of connective tissues such as tendons, ligaments, skin, and bones. Collagen provides structure and strength to these tissues and helps them to withstand stretching and tension. It is made up of long chains of amino acids, primarily glycine, proline, and hydroxyproline, which are arranged in a triple helix structure. There are at least 16 different types of collagen found in the body, each with slightly different structures and functions. Collagen is important for maintaining the integrity and health of tissues throughout the body, and it has been studied for its potential therapeutic uses in various medical conditions.

Hemorheology is the study of the flow properties of blood and its components, including red blood cells, white blood cells, platelets, and plasma. Specifically, it examines how these components interact with each other and with the walls of blood vessels to affect the flow characteristics of blood under different conditions. Hemorheological factors can influence blood viscosity, which is a major determinant of peripheral vascular resistance and cardiac workload. Abnormalities in hemorheology have been implicated in various diseases such as atherosclerosis, hypertension, diabetes, and sickle cell disease.

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

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

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

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

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

Thrombocytopenic purpura (TTP) is a rare blood disorder characterized by the abnormal breakdown of platelets, leading to a low platelet count (thrombocytopenia). Platelets are small blood cells that help your body form clots to stop bleeding. A low platelet count can cause purple spots on the skin (purpura) and easy or excessive bruising or bleeding.

TTP is caused by the formation of blood clots in small blood vessels throughout the body, which can lead to serious complications such as damage to the heart, brain, and kidneys if left untreated. The condition can be acute (sudden onset) or chronic (long-term).

TTP is often caused by an autoimmune response where the body's immune system produces antibodies that attack and destroy a protein called ADAMTS13, which is necessary for breaking down large von Willebrand factor proteins in the blood. Without enough ADAMTS13, these proteins can form clots and deplete platelets, leading to thrombocytopenia and purpura.

Treatment typically involves plasma exchange therapy to replace the missing or nonfunctional ADAMTS13 protein and suppress the immune system's production of antibodies. Corticosteroids, immunosuppressive drugs, and rituximab may also be used in treatment.

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

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

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

Tyrosine is an non-essential amino acid, which means that it can be synthesized by the human body from another amino acid called phenylalanine. Its name is derived from the Greek word "tyros," which means cheese, as it was first isolated from casein, a protein found in cheese.

Tyrosine plays a crucial role in the production of several important substances in the body, including neurotransmitters such as dopamine, norepinephrine, and epinephrine, which are involved in various physiological processes, including mood regulation, stress response, and cognitive functions. It also serves as a precursor to melanin, the pigment responsible for skin, hair, and eye color.

In addition, tyrosine is involved in the structure of proteins and is essential for normal growth and development. Some individuals may require tyrosine supplementation if they have a genetic disorder that affects tyrosine metabolism or if they are phenylketonurics (PKU), who cannot metabolize phenylalanine, which can lead to elevated tyrosine levels in the blood. However, it is important to consult with a healthcare professional before starting any supplementation regimen.

Hemorrhage is defined in the medical context as an excessive loss of blood from the circulatory system, which can occur due to various reasons such as injury, surgery, or underlying health conditions that affect blood clotting or the integrity of blood vessels. The bleeding may be internal, external, visible, or concealed, and it can vary in severity from minor to life-threatening, depending on the location and extent of the bleeding. Hemorrhage is a serious medical emergency that requires immediate attention and treatment to prevent further blood loss, organ damage, and potential death.

Platelet-activating factor (PAF) is a potent phospholipid mediator that plays a significant role in various inflammatory and immune responses. It is a powerful lipid signaling molecule released mainly by activated platelets, neutrophils, monocytes, endothelial cells, and other cell types during inflammation or injury.

PAF has a molecular structure consisting of an alkyl chain linked to a glycerol moiety, a phosphate group, and an sn-2 acetyl group. This unique structure allows PAF to bind to its specific G protein-coupled receptor (PAF-R) on the surface of target cells, triggering various intracellular signaling cascades that result in cell activation, degranulation, and aggregation.

The primary functions of PAF include:

1. Platelet activation and aggregation: PAF stimulates platelets to aggregate, release their granules, and activate the coagulation cascade, which can lead to thrombus formation.
2. Neutrophil and monocyte activation: PAF activates these immune cells, leading to increased adhesion, degranulation, and production of reactive oxygen species (ROS) and pro-inflammatory cytokines.
3. Vasodilation and increased vascular permeability: PAF can cause vasodilation by acting on endothelial cells, leading to an increase in blood flow and facilitating the extravasation of immune cells into inflamed tissues.
4. Bronchoconstriction: In the respiratory system, PAF can induce bronchoconstriction and recruitment of inflammatory cells, contributing to asthma symptoms.
5. Neurotransmission modulation: PAF has been implicated in neuroinflammation and may play a role in neuronal excitability, synaptic plasticity, and cognitive functions.

Dysregulated PAF signaling has been associated with several pathological conditions, including atherosclerosis, sepsis, acute respiratory distress syndrome (ARDS), ischemia-reperfusion injury, and neuroinflammatory disorders. Therefore, targeting the PAF pathway may provide therapeutic benefits in these diseases.

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

Vitronectin receptors, also known as integrin αvβ3 or integrin avb3, are a type of cell surface receptor that bind to the protein vitronectin. These receptors are heterodimeric transmembrane proteins composed of αv and β3 subunits. They play important roles in various biological processes including cell adhesion, migration, proliferation, and survival. Vitronectin receptors are widely expressed in many different cell types, including endothelial cells, smooth muscle cells, and platelets. In addition to vitronectin, these receptors can also bind to other extracellular matrix proteins such as fibronectin, von Willebrand factor, and osteopontin. They are also involved in the regulation of angiogenesis, wound healing, and bone metabolism.

Blood platelet disorders are conditions that affect the number and/or function of platelets, which are small blood cells that help your body form clots to stop bleeding. Normal platelet count ranges from 150,000 to 450,000 platelets per microliter of blood. A lower-than-normal platelet count is called thrombocytopenia, while a higher-than-normal platelet count is called thrombocytosis.

There are several types of platelet disorders, including:

1. Immune thrombocytopenia (ITP): A condition in which the immune system mistakenly attacks and destroys platelets, leading to a low platelet count. ITP can be acute (lasting less than six months) or chronic (lasting longer than six months).
2. Thrombotic thrombocytopenic purpura (TTP): A rare but serious condition that causes blood clots to form in small blood vessels throughout the body, leading to a low platelet count, anemia, and other symptoms.
3. Hemolytic uremic syndrome (HUS): A condition that is often caused by a bacterial infection, which can lead to the formation of blood clots in the small blood vessels of the kidneys, resulting in kidney damage and a low platelet count.
4. Hereditary platelet disorders: Some people inherit genetic mutations that can affect the number or function of their platelets, leading to bleeding disorders such as von Willebrand disease or Bernard-Soulier syndrome.
5. Medication-induced thrombocytopenia: Certain medications can cause a decrease in platelet count as a side effect.
6. Platelet dysfunction disorders: Some conditions can affect the ability of platelets to function properly, leading to bleeding disorders such as von Willebrand disease or storage pool deficiency.

Symptoms of platelet disorders may include easy bruising, prolonged bleeding from cuts or injuries, nosebleeds, blood in urine or stools, and in severe cases, internal bleeding. Treatment for platelet disorders depends on the underlying cause and may include medications, surgery, or other therapies.

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.

Von Willebrand disease (vWD) is a genetic bleeding disorder caused by deficiency or dysfunction of the von Willebrand factor (VWF), a protein involved in blood clotting. The VWF plays a crucial role in the formation of a stable platelet plug during the process of hemostasis, which helps to stop bleeding.

There are three main types of vWD:

1. Type 1: This is the most common form, characterized by a partial quantitative deficiency of functional VWF. Bleeding symptoms are usually mild.
2. Type 2: In this type, there is a qualitative defect in the VWF protein leading to various subtypes (2A, 2B, 2M, and 2N) with different bleeding patterns. Symptoms can range from mild to severe.
3. Type 3: This is the most severe form of vWD, characterized by a near or complete absence of functional VWF and Factor VIII. Affected individuals have a high risk of spontaneous and severe bleeding episodes.

The clinical manifestations of vWD include easy bruising, prolonged nosebleeds (epistaxis), heavy menstrual periods in women, and excessive bleeding after dental procedures, surgeries, or trauma. The diagnosis is made based on laboratory tests that assess VWF antigen levels, VWF activity, and Factor VIII coagulant activity. Treatment options include desmopressin (DDAVP) to stimulate the release of VWF from endothelial cells, recombinant VWF, or plasma-derived VWF concentrates, and antifibrinolytic agents like tranexamic acid to reduce bleeding.

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.

Beta 2-glycoprotein I, also known as apolipoprotein H, is a plasma protein that belongs to the family of proteins called immunoglobulin-binding proteins. It has a molecular weight of approximately 44 kDa and is composed of five domains with similar structures.

Beta 2-glycoprotein I is primarily produced in the liver and circulates in the bloodstream, where it plays a role in several physiological processes, including coagulation, complement activation, and lipid metabolism. It has been identified as an autoantigen in certain autoimmune disorders, such as antiphospholipid syndrome (APS), where autoantibodies against beta 2-glycoprotein I can cause blood clots, miscarriages, and other complications.

In medical terminology, the definition of "beta 2-glycoprotein I" is as follows:

A plasma protein that belongs to the family of immunoglobulin-binding proteins and has a molecular weight of approximately 44 kDa. It is primarily produced in the liver and circulates in the bloodstream, where it plays a role in several physiological processes, including coagulation, complement activation, and lipid metabolism. Autoantibodies against beta 2-glycoprotein I are associated with certain autoimmune disorders, such as antiphospholipid syndrome (APS), where they can cause blood clots, miscarriages, and other complications.

Blood coagulation, also known as blood clotting, is a complex process that occurs in the body to prevent excessive bleeding when a blood vessel is damaged. This process involves several different proteins and chemical reactions that ultimately lead to the formation of a clot.

The coagulation cascade is initiated when blood comes into contact with tissue factor, which is exposed after damage to the blood vessel wall. This triggers a series of enzymatic reactions that activate clotting factors, leading to the formation of a fibrin clot. Fibrin is a protein that forms a mesh-like structure that traps platelets and red blood cells to form a stable clot.

Once the bleeding has stopped, the coagulation process is regulated and inhibited to prevent excessive clotting. The fibrinolytic system degrades the clot over time, allowing for the restoration of normal blood flow.

Abnormalities in the blood coagulation process can lead to bleeding disorders or thrombotic disorders such as deep vein thrombosis and pulmonary embolism.

Immunosorbent techniques are a group of laboratory methods used in immunology and clinical chemistry to isolate or detect specific proteins, antibodies, or antigens from a complex mixture. These techniques utilize the specific binding properties of antibodies or antigens to capture and concentrate target molecules.

The most common immunosorbent technique is the Enzyme-Linked Immunosorbent Assay (ELISA), which involves coating a solid surface with a capture antibody, allowing the sample to bind, washing away unbound material, and then detecting bound antigens or antibodies using an enzyme-conjugated detection reagent. The enzyme catalyzes a colorimetric reaction that can be measured and quantified, providing a sensitive and specific assay for the target molecule.

Other immunosorbent techniques include Radioimmunoassay (RIA), Immunofluorescence Assay (IFA), and Lateral Flow Immunoassay (LFIA). These methods have wide-ranging applications in research, diagnostics, and drug development.

Integrins are a type of cell-adhesion molecule that play a crucial role in cell-cell and cell-extracellular matrix (ECM) interactions. They are heterodimeric transmembrane receptors composed of non-covalently associated α and β subunits, which form more than 24 distinct integrin heterodimers in humans.

Integrins bind to specific ligands, such as ECM proteins (e.g., collagen, fibronectin, laminin), cell surface molecules, and soluble factors, through their extracellular domains. The intracellular domains of integrins interact with the cytoskeleton and various signaling proteins, allowing them to transduce signals from the ECM into the cell (outside-in signaling) and vice versa (inside-out signaling).

These molecular interactions are essential for numerous biological processes, including cell adhesion, migration, proliferation, differentiation, survival, and angiogenesis. Dysregulation of integrin function has been implicated in various pathological conditions, such as cancer, fibrosis, inflammation, and autoimmune diseases.

Viral envelope proteins are structural proteins found in the envelope that surrounds many types of viruses. These proteins play a crucial role in the virus's life cycle, including attachment to host cells, fusion with the cell membrane, and entry into the host cell. They are typically made up of glycoproteins and are often responsible for eliciting an immune response in the host organism. The exact structure and function of viral envelope proteins vary between different types of viruses.

Collagen receptors are a type of cell surface receptor that bind to collagen molecules, which are the most abundant proteins in the extracellular matrix (ECM) of connective tissues. These receptors play important roles in various biological processes, including cell adhesion, migration, differentiation, and survival.

Collagen receptors can be classified into two major groups: integrins and discoidin domain receptors (DDRs). Integrins are heterodimeric transmembrane proteins that consist of an alpha and a beta subunit. They bind to collagens via their arginine-glycine-aspartic acid (RGD) motif, which is located in the triple-helical domain of collagen molecules. Integrins mediate cell-collagen interactions by clustering and forming focal adhesions, which are large protein complexes that connect the ECM to the cytoskeleton.

DDRs are receptor tyrosine kinases (RTKs) that contain a discoidin domain in their extracellular region, which is responsible for collagen binding. DDRs bind to collagens via their non-RGD motifs and induce intracellular signaling pathways that regulate cell behavior.

Abnormalities in collagen receptor function have been implicated in various diseases, including fibrosis, cancer, and inflammation. Therefore, understanding the structure and function of collagen receptors is crucial for developing novel therapeutic strategies to treat these conditions.

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.

Cell adhesion refers to the binding of cells to extracellular matrices or to other cells, a process that is fundamental to the development, function, and maintenance of multicellular organisms. Cell adhesion is mediated by various cell surface receptors, such as integrins, cadherins, and immunoglobulin-like cell adhesion molecules (Ig-CAMs), which interact with specific ligands in the extracellular environment. These interactions lead to the formation of specialized junctions, such as tight junctions, adherens junctions, and desmosomes, that help to maintain tissue architecture and regulate various cellular processes, including proliferation, differentiation, migration, and survival. Disruptions in cell adhesion can contribute to a variety of diseases, including cancer, inflammation, and degenerative disorders.

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

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

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

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

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

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

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

Amidines are organic compounds that contain a functional group with the structure R-C=N-R, where R can be an alkyl or aromatic group. This functional group consists of a carbonyl (C=O) group and a nitrogen atom (N) connected to two organic groups (R).

In medical terminology, amidines are not commonly used. However, some amidine derivatives have been investigated for their potential therapeutic properties. For example, certain amidine compounds have shown antimicrobial, anti-inflammatory, and antiviral activities. Some of these compounds have also been studied as potential drugs for the treatment of various diseases, including cancer, cardiovascular disease, and neurological disorders.

It is important to note that while some amidines may have therapeutic potential, they can also be toxic at high concentrations and should be handled with care.

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

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

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

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

Coronary thrombosis is a medical condition that refers to the formation of a blood clot (thrombus) inside a coronary artery, which supplies oxygenated blood to the heart muscle. The development of a thrombus can partially or completely obstruct blood flow, leading to insufficient oxygen supply to the heart muscle. This can cause chest pain (angina) or a heart attack (myocardial infarction), depending on the severity and duration of the blockage.

Coronary thrombosis often results from the rupture of an atherosclerotic plaque, a buildup of cholesterol, fat, calcium, and other substances in the inner lining (endothelium) of the coronary artery. The ruptured plaque exposes the underlying tissue to the bloodstream, triggering the coagulation cascade and resulting in the formation of a thrombus.

Immediate medical attention is crucial for managing coronary thrombosis, as timely treatment can help restore blood flow, prevent further damage to the heart muscle, and reduce the risk of complications such as heart failure or life-threatening arrhythmias. Treatment options may include medications, such as antiplatelet agents, anticoagulants, and thrombolytic drugs, or interventional procedures like angioplasty and stenting to open the blocked artery. In some cases, surgical intervention, such as coronary artery bypass grafting (CABG), may be necessary.

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

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

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

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

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

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.

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

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

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

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

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

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

Hemostasis is the physiological process that occurs to stop bleeding (bleeding control) when a blood vessel is damaged. This involves the interaction of platelets, vasoconstriction, and blood clotting factors leading to the formation of a clot. The ultimate goal of hemostasis is to maintain the integrity of the vascular system while preventing excessive blood loss.

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.

Myocardial infarction (MI), also known as a heart attack, is a medical condition characterized by the death of a segment of heart muscle (myocardium) due to the interruption of its blood supply. This interruption is most commonly caused by the blockage of a coronary artery by a blood clot formed on the top of an atherosclerotic plaque, which is a buildup of cholesterol and other substances in the inner lining of the artery.

The lack of oxygen and nutrients supply to the heart muscle tissue results in damage or death of the cardiac cells, causing the affected area to become necrotic. The extent and severity of the MI depend on the size of the affected area, the duration of the occlusion, and the presence of collateral circulation.

Symptoms of a myocardial infarction may include chest pain or discomfort, shortness of breath, nausea, lightheadedness, and sweating. Immediate medical attention is necessary to restore blood flow to the affected area and prevent further damage to the heart muscle. Treatment options for MI include medications, such as thrombolytics, antiplatelet agents, and pain relievers, as well as procedures such as percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

Anticoagulants are a class of medications that work to prevent the formation of blood clots in the body. They do this by inhibiting the coagulation cascade, which is a series of chemical reactions that lead to the formation of a clot. Anticoagulants can be given orally, intravenously, or subcutaneously, depending on the specific drug and the individual patient's needs.

There are several different types of anticoagulants, including:

1. Heparin: This is a naturally occurring anticoagulant that is often used in hospitalized patients who require immediate anticoagulation. It works by activating an enzyme called antithrombin III, which inhibits the formation of clots.
2. Low molecular weight heparin (LMWH): LMWH is a form of heparin that has been broken down into smaller molecules. It has a longer half-life than standard heparin and can be given once or twice daily by subcutaneous injection.
3. Direct oral anticoagulants (DOACs): These are newer oral anticoagulants that work by directly inhibiting specific clotting factors in the coagulation cascade. Examples include apixaban, rivaroxaban, and dabigatran.
4. Vitamin K antagonists: These are older oral anticoagulants that work by inhibiting the action of vitamin K, which is necessary for the formation of clotting factors. Warfarin is an example of a vitamin K antagonist.

Anticoagulants are used to prevent and treat a variety of conditions, including deep vein thrombosis (DVT), pulmonary embolism (PE), atrial fibrillation, and prosthetic heart valve thrombosis. It is important to note that anticoagulants can increase the risk of bleeding, so they must be used with caution and regular monitoring of blood clotting times may be required.

Thrombospondins (TSPs) are a family of multifunctional glycoproteins that are involved in various biological processes, including cell adhesion, migration, proliferation, differentiation, and angiogenesis. They were initially identified as calcium-binding proteins that are secreted by platelets during blood clotting (thrombosis), hence the name thrombospondin.

There are five members in the TSP family, designated as TSP-1 to TSP-5, and they share a common structure consisting of several domains, including an N-terminal domain, a series of type 1 repeats, a type 2 (von Willebrand factor C) repeat, a type 3 repeat, and a C-terminal domain.

TSP-1 and TSP-2 are secreted proteins that have been extensively studied for their roles in the regulation of angiogenesis, the process of new blood vessel formation. They bind to various extracellular matrix components, growth factors, and cell surface receptors, and can either promote or inhibit angiogenesis depending on the context.

TSP-3 to TSP-5 are expressed in a variety of tissues and play roles in cell adhesion, migration, and differentiation. They have been implicated in various pathological conditions, including cancer, fibrosis, and neurodegenerative diseases.

Overall, thrombospondins are important regulators of extracellular matrix dynamics and cell-matrix interactions, and their dysregulation has been associated with a variety of diseases.

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

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

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

Cell surface receptors, also known as membrane receptors, are proteins located on the cell membrane that bind to specific molecules outside the cell, known as ligands. These receptors play a crucial role in signal transduction, which is the process of converting an extracellular signal into an intracellular response.

Cell surface receptors can be classified into several categories based on their structure and mechanism of action, including:

1. Ion channel receptors: These receptors contain a pore that opens to allow ions to flow across the cell membrane when they bind to their ligands. This ion flux can directly activate or inhibit various cellular processes.
2. G protein-coupled receptors (GPCRs): These receptors consist of seven transmembrane domains and are associated with heterotrimeric G proteins that modulate intracellular signaling pathways upon ligand binding.
3. Enzyme-linked receptors: These receptors possess an intrinsic enzymatic activity or are linked to an enzyme, which becomes activated when the receptor binds to its ligand. This activation can lead to the initiation of various signaling cascades within the cell.
4. Receptor tyrosine kinases (RTKs): These receptors contain intracellular tyrosine kinase domains that become activated upon ligand binding, leading to the phosphorylation and activation of downstream signaling molecules.
5. Integrins: These receptors are transmembrane proteins that mediate cell-cell or cell-matrix interactions by binding to extracellular matrix proteins or counter-receptors on adjacent cells. They play essential roles in cell adhesion, migration, and survival.

Cell surface receptors are involved in various physiological processes, including neurotransmission, hormone signaling, immune response, and cell growth and differentiation. Dysregulation of these receptors can contribute to the development of numerous diseases, such as cancer, diabetes, and neurological disorders.

Fibrin is defined as a protein that is formed from fibrinogen during the clotting of blood. It plays an essential role in the formation of blood clots, also known as a clotting or coagulation cascade. When an injury occurs and bleeding starts, fibrin threads form a net-like structure that entraps platelets and red blood cells to create a stable clot, preventing further loss of blood.

The process of forming fibrin from fibrinogen is initiated by thrombin, another protein involved in the coagulation cascade. Thrombin cleaves fibrinogen into fibrin monomers, which then polymerize to form long strands of fibrin. These strands cross-link with each other through a process catalyzed by factor XIIIa, forming a stable clot that protects the wound and promotes healing.

It is important to note that abnormalities in fibrin formation or breakdown can lead to bleeding disorders or thrombotic conditions, respectively. Proper regulation of fibrin production and degradation is crucial for maintaining healthy hemostasis and preventing excessive clotting or bleeding.

Affinity chromatography is a type of chromatography technique used in biochemistry and molecular biology to separate and purify proteins based on their biological characteristics, such as their ability to bind specifically to certain ligands or molecules. This method utilizes a stationary phase that is coated with a specific ligand (e.g., an antibody, antigen, receptor, or enzyme) that selectively interacts with the target protein in a sample.

The process typically involves the following steps:

1. Preparation of the affinity chromatography column: The stationary phase, usually a solid matrix such as agarose beads or magnetic beads, is modified by covalently attaching the ligand to its surface.
2. Application of the sample: The protein mixture is applied to the top of the affinity chromatography column, allowing it to flow through the stationary phase under gravity or pressure.
3. Binding and washing: As the sample flows through the column, the target protein selectively binds to the ligand on the stationary phase, while other proteins and impurities pass through. The column is then washed with a suitable buffer to remove any unbound proteins and contaminants.
4. Elution of the bound protein: The target protein can be eluted from the column using various methods, such as changing the pH, ionic strength, or polarity of the buffer, or by introducing a competitive ligand that displaces the bound protein.
5. Collection and analysis: The eluted protein fraction is collected and analyzed for purity and identity, often through techniques like SDS-PAGE or mass spectrometry.

Affinity chromatography is a powerful tool in biochemistry and molecular biology due to its high selectivity and specificity, enabling the efficient isolation of target proteins from complex mixtures. However, it requires careful consideration of the binding affinity between the ligand and the protein, as well as optimization of the elution conditions to minimize potential damage or denaturation of the purified protein.

Glycosylation is the enzymatic process of adding a sugar group, or glycan, to a protein, lipid, or other organic molecule. This post-translational modification plays a crucial role in modulating various biological functions, such as protein stability, trafficking, and ligand binding. The structure and composition of the attached glycans can significantly influence the functional properties of the modified molecule, contributing to cell-cell recognition, signal transduction, and immune response regulation. Abnormal glycosylation patterns have been implicated in several disease states, including cancer, diabetes, and neurodegenerative disorders.

Unstable angina is a term used in cardiology to describe chest pain or discomfort that occurs suddenly and unexpectedly, often at rest or with minimal physical exertion. It is caused by an insufficient supply of oxygen-rich blood to the heart muscle due to reduced blood flow, typically as a result of partial or complete blockage of the coronary arteries.

Unlike stable angina, which tends to occur predictably during physical activity and can be relieved with rest or nitroglycerin, unstable angina is more severe, unpredictable, and may not respond to traditional treatments. It is considered a medical emergency because it can be a sign of an impending heart attack or other serious cardiac event.

Unstable angina is often treated in the hospital with medications such as nitroglycerin, beta blockers, calcium channel blockers, and antiplatelet agents to improve blood flow to the heart and prevent further complications. In some cases, more invasive treatments such as coronary angioplasty or bypass surgery may be necessary to restore blood flow to the affected areas of the heart.

Pyrrolidines are not a medical term per se, but they are a chemical compound that can be encountered in the field of medicine and pharmacology. Pyrrolidine is an organic compound with the molecular formula (CH2)4NH. It is a cyclic secondary amine, which means it contains a nitrogen atom surrounded by four carbon atoms in a ring structure.

Pyrrolidines can be found in certain natural substances and are also synthesized for use in pharmaceuticals and research. They have been used as building blocks in the synthesis of various drugs, including some muscle relaxants, antipsychotics, and antihistamines. Additionally, pyrrolidine derivatives can be found in certain plants and fungi, where they may contribute to biological activity or toxicity.

It is important to note that while pyrrolidines themselves are not a medical condition or diagnosis, understanding their chemical properties and uses can be relevant to the study and development of medications.

I believe there might be a misunderstanding in your question. "Dogs" is not a medical term or condition. It is the common name for a domesticated carnivore of the family Canidae, specifically the genus Canis, which includes wolves, foxes, and other extant and extinct species of mammals. Dogs are often kept as pets and companions, and they have been bred in a wide variety of forms and sizes for different purposes, such as hunting, herding, guarding, assisting police and military forces, and providing companionship and emotional support.

If you meant to ask about a specific medical condition or term related to dogs, please provide more context so I can give you an accurate answer.

Capillary action, also known as capillarity, is the ability of a liquid to rise or get drawn into narrow spaces, such as small tubes or gaps between particles, against gravity. This phenomenon occurs due to the attractive forces between the molecules of the liquid and the solid surface of the narrow space.

The height to which a liquid will rise in a capillary tube is determined by several factors, including the surface tension of the liquid, the radius of the capillary tube, and the adhesive forces between the liquid and the tube's material. In general, liquids with higher surface tension and stronger adhesion to the tube's material will rise higher than those with lower surface tension and weaker adhesion.

Capillary action plays an essential role in many natural and industrial processes, such as water absorption by plants, fluid transport in biological systems, and ink movement in fountain pens.

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.

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.

Glycopeptides are a class of antibiotics that are characterized by their complex chemical structure, which includes both peptide and carbohydrate components. These antibiotics are produced naturally by certain types of bacteria and are effective against a range of Gram-positive bacterial infections, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE).

The glycopeptide antibiotics work by binding to the bacterial cell wall precursor, preventing the cross-linking of peptidoglycan chains that is necessary for the formation of a strong and rigid cell wall. This leads to the death of the bacteria.

Examples of glycopeptides include vancomycin, teicoplanin, and dalbavancin. While these antibiotics have been used successfully for many years, their use is often limited due to concerns about the emergence of resistance and potential toxicity.

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

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

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

Isoxazoles are not a medical term, but a chemical compound. They are organic compounds containing a five-membered ring consisting of one nitrogen atom, one oxygen atom, and three carbon atoms. Isoxazoles have various applications in the pharmaceutical industry as they can be used to synthesize different drugs. Some isoxazole derivatives have been studied for their potential medicinal properties, such as anti-inflammatory, analgesic, and antipyretic effects. However, isoxazoles themselves are not a medical diagnosis or treatment.

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.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

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

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

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

Coronary balloon angioplasty is a minimally invasive medical procedure used to widen narrowed or obstructed coronary arteries (the blood vessels that supply oxygen-rich blood to the heart muscle) and improve blood flow to the heart. This procedure is typically performed in conjunction with the insertion of a stent, a small mesh tube that helps keep the artery open.

During coronary balloon angioplasty, a thin, flexible catheter with a deflated balloon at its tip is inserted into a blood vessel, usually through a small incision in the groin or arm. The catheter is then guided to the narrowed or obstructed section of the coronary artery. Once in position, the balloon is inflated to compress the plaque against the artery wall and widen the lumen (the inner space) of the artery. This helps restore blood flow to the heart muscle.

The procedure is typically performed under local anesthesia and conscious sedation to minimize discomfort. Coronary balloon angioplasty is a relatively safe and effective treatment for many people with coronary artery disease, although complications such as bleeding, infection, or re-narrowing of the artery (restenosis) can occur in some cases.

Aurintricarboxylic acid (ATA) is a polyphenolic compound with antioxidant and anti-inflammatory properties. Its chemical formula is C14H8O8. It is known to inhibit several enzymes, including lipoxygenases, cyclooxygenases, and phospholipases, and has been studied for its potential therapeutic effects in various diseases such as cancer, neurodegenerative disorders, and cardiovascular diseases. However, more research is needed to fully understand its mechanisms of action and clinical applications.

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

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

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

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

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

A dose-response relationship in the context of drugs refers to the changes in the effects or symptoms that occur as the dose of a drug is increased or decreased. Generally, as the dose of a drug is increased, the severity or intensity of its effects also increases. Conversely, as the dose is decreased, the effects of the drug become less severe or may disappear altogether.

The dose-response relationship is an important concept in pharmacology and toxicology because it helps to establish the safe and effective dosage range for a drug. By understanding how changes in the dose of a drug affect its therapeutic and adverse effects, healthcare providers can optimize treatment plans for their patients while minimizing the risk of harm.

The dose-response relationship is typically depicted as a curve that shows the relationship between the dose of a drug and its effect. The shape of the curve may vary depending on the drug and the specific effect being measured. Some drugs may have a steep dose-response curve, meaning that small changes in the dose can result in large differences in the effect. Other drugs may have a more gradual dose-response curve, where larger changes in the dose are needed to produce significant effects.

In addition to helping establish safe and effective dosages, the dose-response relationship is also used to evaluate the potential therapeutic benefits and risks of new drugs during clinical trials. By systematically testing different doses of a drug in controlled studies, researchers can identify the optimal dosage range for the drug and assess its safety and efficacy.

Orosomucoid, also known as α-1-acid glycoprotein or AAG, is a protein found in human plasma. It's a member of the acute phase proteins, which are produced in higher amounts during inflammation and infection. Orosomucoid has a molecular weight of approximately 41-43 kDa and is composed of a single polypeptide chain with five N-linked glycosylation sites. It plays a role in protecting tissues from various harmful substances, such as proteases and oxidants, by binding to them and preventing their interaction with cells. Additionally, orosomucoid has been studied as a potential biomarker for several diseases due to its altered levels during inflammation and cancer.

Alanine is an alpha-amino acid that is used in the biosynthesis of proteins. The molecular formula for alanine is C3H7NO2. It is a non-essential amino acid, which means that it can be produced by the human body through the conversion of other nutrients, such as pyruvate, and does not need to be obtained directly from the diet.

Alanine is classified as an aliphatic amino acid because it contains a simple carbon side chain. It is also a non-polar amino acid, which means that it is hydrophobic and tends to repel water. Alanine plays a role in the metabolism of glucose and helps to regulate blood sugar levels. It is also involved in the transfer of nitrogen between tissues and helps to maintain the balance of nitrogen in the body.

In addition to its role as a building block of proteins, alanine is also used as a neurotransmitter in the brain and has been shown to have a calming effect on the nervous system. It is found in many foods, including meats, poultry, fish, eggs, dairy products, and legumes.

"Viper venoms" refer to the toxic secretions produced by members of the Viperidae family of snakes, which include pit vipers (such as rattlesnakes, copperheads, and cottonmouths) and true vipers (like adders, vipers, and gaboon vipers). These venoms are complex mixtures of proteins, enzymes, and other bioactive molecules that can cause a wide range of symptoms in prey or predators, including local tissue damage, pain, swelling, bleeding, and potentially life-threatening systemic effects such as coagulopathy, cardiovascular shock, and respiratory failure.

The composition of viper venoms varies widely between different species and even among individuals within the same species. However, many viper venoms contain a variety of enzymes (such as phospholipases A2, metalloproteinases, and serine proteases) that can cause tissue damage and disrupt vital physiological processes in the victim. Additionally, some viper venoms contain neurotoxins that can affect the nervous system and cause paralysis or other neurological symptoms.

Understanding the composition and mechanisms of action of viper venoms is important for developing effective treatments for venomous snakebites, as well as for gaining insights into the evolution and ecology of these fascinating and diverse creatures.

Myelin-Associated Glycoprotein (MAG) is a glycoprotein found on the surface of myelin sheaths, which are the protective insulating layers around nerve fibers in the nervous system. MAG plays a role in the adhesion and interaction between the myelin sheath and the axon it surrounds. It's particularly important during the development and maintenance of the nervous system. Additionally, MAG has been implicated in the regulation of neuronal growth and signal transmission. In certain autoimmune diseases like Guillain-Barré syndrome, the immune system may mistakenly attack MAG, leading to damage of the myelin sheath and associated neurological symptoms.

Disulfides are a type of organic compound that contains a sulfur-sulfur bond. In the context of biochemistry and medicine, disulfide bonds are often found in proteins, where they play a crucial role in maintaining their three-dimensional structure and function. These bonds form when two sulfhydryl groups (-SH) on cysteine residues within a protein molecule react with each other, releasing a molecule of water and creating a disulfide bond (-S-S-) between the two cysteines. Disulfide bonds can be reduced back to sulfhydryl groups by various reducing agents, which is an important process in many biological reactions. The formation and reduction of disulfide bonds are critical for the proper folding, stability, and activity of many proteins, including those involved in various physiological processes and diseases.

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

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

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

Integrin α2β1, also known as very late antigen-2 (VLA-2) or laminin receptor, is a heterodimeric transmembrane receptor protein composed of α2 and β1 subunits. It belongs to the integrin family of adhesion molecules that play crucial roles in cell-cell and cell-extracellular matrix (ECM) interactions.

Integrin α2β1 is widely expressed on various cell types, including fibroblasts, endothelial cells, smooth muscle cells, and some hematopoietic cells. It functions as a receptor for several ECM proteins, such as collagens (type I, II, III, and V), laminin, and fibronectin. The binding of integrin α2β1 to these ECM components mediates cell adhesion, migration, proliferation, differentiation, and survival, thereby regulating various physiological and pathological processes, such as tissue repair, angiogenesis, inflammation, and tumor progression.

In addition, integrin α2β1 has been implicated in several diseases, including fibrosis, atherosclerosis, and cancer. Therefore, targeting this integrin with therapeutic strategies may provide potential benefits for treating these conditions.

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.

Thromboxanes are a type of lipid compound that is derived from arachidonic acid, a type of fatty acid found in the cell membranes of many organisms. They are synthesized in the body through the action of an enzyme called cyclooxygenase (COX).

Thromboxanes are primarily produced by platelets, a type of blood cell that plays a key role in clotting. Once formed, thromboxanes act as powerful vasoconstrictors, causing blood vessels to narrow and blood flow to decrease. They also promote the aggregation of platelets, which can lead to the formation of blood clots.

Thromboxanes are involved in many physiological processes, including hemostasis (the process by which bleeding is stopped) and inflammation. However, excessive production of thromboxanes has been implicated in a number of pathological conditions, such as heart attacks, strokes, and pulmonary hypertension.

There are several different types of thromboxanes, including thromboxane A2 (TXA2) and thromboxane B2 (TXB2). TXA2 is the most biologically active form and has a very short half-life, while TXB2 is a more stable metabolite that can be measured in the blood to assess thromboxane production.

Thromboxane A2 (TXA2) is a potent prostanoid, a type of lipid compound derived from arachidonic acid. It is primarily produced and released by platelets upon activation during the process of hemostasis (the body's response to stop bleeding). TXA2 acts as a powerful vasoconstrictor, causing blood vessels to narrow, which helps limit blood loss at the site of injury. Additionally, it promotes platelet aggregation, contributing to the formation of a stable clot and preventing further bleeding. However, uncontrolled or excessive production of TXA2 can lead to thrombotic events such as heart attacks and strokes. Its effects are balanced by prostacyclin (PGI2), which is produced by endothelial cells and has opposing actions, acting as a vasodilator and inhibiting platelet aggregation. The balance between TXA2 and PGI2 helps maintain vascular homeostasis.

A syndrome, in medical terms, is a set of symptoms that collectively indicate or characterize a disease, disorder, or underlying pathological process. It's essentially a collection of signs and/or symptoms that frequently occur together and can suggest a particular cause or condition, even though the exact physiological mechanisms might not be fully understood.

For example, Down syndrome is characterized by specific physical features, cognitive delays, and other developmental issues resulting from an extra copy of chromosome 21. Similarly, metabolic syndromes like diabetes mellitus type 2 involve a group of risk factors such as obesity, high blood pressure, high blood sugar, and abnormal cholesterol or triglyceride levels that collectively increase the risk of heart disease, stroke, and diabetes.

It's important to note that a syndrome is not a specific diagnosis; rather, it's a pattern of symptoms that can help guide further diagnostic evaluation and management.

Filamins are a group of proteins that play a crucial role in the structure and function of the cytoskeleton, which is the internal framework of cells. They belong to a family of proteins known as "cytoskeletal cross-linking proteins." There are three main types of filamins (A, B, and C) in humans, encoded by different genes but sharing similar structures and functions.

Filamins have several domains that allow them to interact with various cellular components, including actin filaments, membrane receptors, signaling molecules, and other structural proteins. One of their primary roles is to connect actin filaments to each other and to other cellular structures, providing stability and organization to the cytoskeleton. This helps maintain cell shape, facilitate cell movement, and enable proper intracellular transport.

Additionally, filamins are involved in various signaling pathways and can regulate cellular processes such as gene expression, cell proliferation, differentiation, and survival. Dysregulation of filamin function has been implicated in several diseases, including cancer, cardiovascular disorders, neurological conditions, and musculoskeletal disorders.

Mechanical stress, in the context of physiology and medicine, refers to any type of force that is applied to body tissues or organs, which can cause deformation or displacement of those structures. Mechanical stress can be either external, such as forces exerted on the body during physical activity or trauma, or internal, such as the pressure changes that occur within blood vessels or other hollow organs.

Mechanical stress can have a variety of effects on the body, depending on the type, duration, and magnitude of the force applied. For example, prolonged exposure to mechanical stress can lead to tissue damage, inflammation, and chronic pain. Additionally, abnormal or excessive mechanical stress can contribute to the development of various musculoskeletal disorders, such as tendinitis, osteoarthritis, and herniated discs.

In order to mitigate the negative effects of mechanical stress, the body has a number of adaptive responses that help to distribute forces more evenly across tissues and maintain structural integrity. These responses include changes in muscle tone, joint positioning, and connective tissue stiffness, as well as the remodeling of bone and other tissues over time. However, when these adaptive mechanisms are overwhelmed or impaired, mechanical stress can become a significant factor in the development of various pathological conditions.

Genetic polymorphism refers to the occurrence of multiple forms (called alleles) of a particular gene within a population. These variations in the DNA sequence do not generally affect the function or survival of the organism, but they can contribute to differences in traits among individuals. Genetic polymorphisms can be caused by single nucleotide changes (SNPs), insertions or deletions of DNA segments, or other types of genetic rearrangements. They are important for understanding genetic diversity and evolution, as well as for identifying genetic factors that may contribute to disease susceptibility in humans.

Coronary artery disease, often simply referred to as coronary disease, is a condition in which the blood vessels that supply oxygen-rich blood to the heart become narrowed or blocked due to the buildup of fatty deposits called plaques. This can lead to chest pain (angina), shortness of breath, or in severe cases, a heart attack.

The medical definition of coronary artery disease is:

A condition characterized by the accumulation of atheromatous plaques in the walls of the coronary arteries, leading to decreased blood flow and oxygen supply to the myocardium (heart muscle). This can result in symptoms such as angina pectoris, shortness of breath, or arrhythmias, and may ultimately lead to myocardial infarction (heart attack) or heart failure.

Risk factors for coronary artery disease include age, smoking, high blood pressure, high cholesterol, diabetes, obesity, physical inactivity, and a family history of the condition. Lifestyle changes such as quitting smoking, exercising regularly, eating a healthy diet, and managing stress can help reduce the risk of developing coronary artery disease. Medical treatments may include medications to control blood pressure, cholesterol levels, or irregular heart rhythms, as well as procedures such as angioplasty or bypass surgery to improve blood flow to the heart.

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

Treatment outcome is a term used to describe the result or effect of medical treatment on a patient's health status. It can be measured in various ways, such as through symptoms improvement, disease remission, reduced disability, improved quality of life, or survival rates. The treatment outcome helps healthcare providers evaluate the effectiveness of a particular treatment plan and make informed decisions about future care. It is also used in clinical research to compare the efficacy of different treatments and improve patient care.

Neonatal alloimmune thrombocytopenia (NAIT) is a medical condition that occurs in newborns when the mother's immune system produces antibodies against the baby's platelets. This happens because the baby inherits platelet antigens from the father that are different from those of the mother, causing an immune response that destroys the baby's platelets.

NAIT is a rare but serious condition that can lead to severe bleeding in newborns, particularly in the brain, which can result in long-term neurological damage or even death. Symptoms of NAIT may include petechiae (small red spots on the skin caused by bleeding under the skin), bruising, and excessive bleeding during delivery or after circumcision.

Diagnosis of NAIT is typically made through blood tests that measure platelet counts and identify the specific platelet antigens involved. Treatment may include transfusions of platelets or plasma, corticosteroids to suppress the mother's immune response, or intravenous immunoglobulin (IVIG) therapy to help prevent further destruction of the baby's platelets. In severe cases, exchange transfusion may be necessary to remove the antibodies from the baby's bloodstream.

Prevention of NAIT involves identifying mothers at risk and administering prophylactic treatment during pregnancy or before delivery. This is typically done through testing for platelet antigens in both parents and providing immunoglobulin therapy to the mother if there is a mismatch.

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.

The endothelium is a thin layer of simple squamous epithelial cells that lines the interior surface of blood vessels, lymphatic vessels, and heart chambers. The vascular endothelium, specifically, refers to the endothelial cells that line the blood vessels. These cells play a crucial role in maintaining vascular homeostasis by regulating vasomotor tone, coagulation, platelet activation, inflammation, and permeability of the vessel wall. They also contribute to the growth and repair of the vascular system and are involved in various pathological processes such as atherosclerosis, hypertension, and diabetes.

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

A ligand, in the context of biochemistry and medicine, is a molecule that binds to a specific site on a protein or a larger biomolecule, such as an enzyme or a receptor. This binding interaction can modify the function or activity of the target protein, either activating it or inhibiting it. Ligands can be small molecules, like hormones or neurotransmitters, or larger structures, like antibodies. The study of ligand-protein interactions is crucial for understanding cellular processes and developing drugs, as many therapeutic compounds function by binding to specific targets within the body.

Isoantigens are antigens that are present on the cells or tissues of one individual of a species, but are absent or different in another individual of the same species. They are also known as "alloantigens." Isoantigens are most commonly found on the surface of red blood cells and other tissues, and they can stimulate an immune response when transplanted into a different individual. This is because the recipient's immune system recognizes the isoantigens as foreign and mounts a defense against them. Isoantigens are important in the field of transplantation medicine, as they must be carefully matched between donor and recipient to reduce the risk of rejection.

A stent is a small mesh tube that's used to treat narrow or weak arteries. Arteries are blood vessels that carry blood away from your heart to other parts of your body. A stent is placed in an artery as part of a procedure called angioplasty. Angioplasty restores blood flow through narrowed or blocked arteries by inflating a tiny balloon inside the blocked artery to widen it.

The stent is then inserted into the widened artery to keep it open. The stent is usually made of metal, but some are coated with medication that is slowly and continuously released to help prevent the formation of scar tissue in the artery. This can reduce the chance of the artery narrowing again.

Stents are also used in other parts of the body, such as the neck (carotid artery) and kidneys (renal artery), to help maintain blood flow and prevent blockages. They can also be used in the urinary system to treat conditions like ureteropelvic junction obstruction or narrowing of the urethra.

'Agkistrodon' is a genus of venomous snakes commonly known as pit vipers, found predominantly in North America and parts of Asia. This genus includes several species, among them the copperhead (A. contortrix), cottonmouth or water moccasin (A. piscivorus), and the cantil (A. bilineatus). These snakes are characterized by their triangular heads, heat-sensing pits between the eyes and nostrils, and elliptical pupils. They deliver venom through hollow fangs and can cause significant harm to humans if they bite.

It is important to note that 'Agkistrodon' species are often misidentified due to their similarities with other pit vipers. Accurate identification of a snakebite victim is crucial for proper medical treatment, so seeking professional help from herpetologists or medical professionals is highly recommended in such situations.

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.

14-3-3 proteins are a family of conserved regulatory molecules found in eukaryotic cells. They are involved in various cellular processes, such as signal transduction, cell cycle regulation, and apoptosis (programmed cell death). These proteins bind to specific phosphoserine-containing motifs on their target proteins, thereby modulating their activity, localization, or stability. Dysregulation of 14-3-3 proteins has been implicated in several human diseases, including cancer, neurodegenerative disorders, and diabetes.

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.

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

CD36 is a type of protein found on the surface of certain cells in the human body, including platelets, white blood cells (monocytes and macrophages), and fat (adipose) cells. It is a type of scavenger receptor that plays a role in various biological processes, such as:

1. Fatty acid uptake and metabolism: CD36 helps facilitate the transport of long-chain fatty acids into cells for energy production and storage.
2. Inflammation and immune response: CD36 is involved in the recognition and clearance of foreign substances (pathogens) and damaged or dying cells, which can trigger an immune response.
3. Angiogenesis: CD36 has been implicated in the regulation of blood vessel formation (angiogenesis), particularly during wound healing and tumor growth.
4. Atherosclerosis: CD36 has been associated with the development and progression of atherosclerosis, a condition characterized by the buildup of fats, cholesterol, and other substances in and on the artery walls. This is due to its role in the uptake of oxidized low-density lipoprotein (oxLDL) by macrophages, leading to the formation of foam cells and the development of fatty streaks in the arterial wall.
5. Infectious diseases: CD36 has been identified as a receptor for various pathogens, including malaria parasites, HIV, and some bacteria, which can use this protein to gain entry into host cells.

As an antigen, CD36 is a molecule that can be targeted by the immune system to produce an immune response. Antibodies against CD36 have been found in various diseases, such as autoimmune disorders and certain infections. Modulation of CD36 activity has been suggested as a potential therapeutic strategy for several conditions, including atherosclerosis, diabetes, and infectious diseases.

"Papio" is a term used in the field of primatology, specifically for a genus of Old World monkeys known as baboons. It's not typically used in human or medical contexts. Baboons are large monkeys with robust bodies and distinctive dog-like faces. They are native to various parts of Africa and are known for their complex social structures and behaviors.

Tissue Plasminogen Activator (tPA) is a thrombolytic enzyme, which means it dissolves blood clots. It is naturally produced by the endothelial cells that line the interior surface of blood vessels. tPA activates plasminogen, a zymogen, to convert it into plasmin, a protease that breaks down fibrin, the structural protein in blood clots. This enzyme is used medically as a thrombolytic drug under various brand names, such as Activase and Alteplase, to treat conditions like acute ischemic stroke, pulmonary embolism, and deep vein thrombosis by dissolving the clots and restoring blood flow.

The double-blind method is a study design commonly used in research, including clinical trials, to minimize bias and ensure the objectivity of results. In this approach, both the participants and the researchers are unaware of which group the participants are assigned to, whether it be the experimental group or the control group. This means that neither the participants nor the researchers know who is receiving a particular treatment or placebo, thus reducing the potential for bias in the evaluation of outcomes. The assignment of participants to groups is typically done by a third party not involved in the study, and the codes are only revealed after all data have been collected and analyzed.

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

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

"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.

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.

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.

Hemagglutinins are proteins found on the surface of some viruses, including influenza viruses. They have the ability to bind to specific receptors on the surface of red blood cells, causing them to clump together (a process known as hemagglutination). This property is what allows certain viruses to infect host cells and cause disease. Hemagglutinins play a crucial role in the infection process of influenza viruses, as they facilitate the virus's entry into host cells by binding to sialic acid receptors on the surface of respiratory epithelial cells. There are 18 different subtypes of hemagglutinin (H1-H18) found in various influenza A viruses, and they are a major target of the immune response to influenza infection. Vaccines against influenza contain hemagglutinins from the specific strains of virus that are predicted to be most prevalent in a given season, and induce immunity by stimulating the production of antibodies that can neutralize the virus.

A precipitin test is a type of immunodiagnostic test used to detect and measure the presence of specific antibodies or antigens in a patient's serum. The test is based on the principle of antigen-antibody interaction, where the addition of an antigen to a solution containing its corresponding antibody results in the formation of an insoluble immune complex known as a precipitin.

In this test, a small amount of the patient's serum is added to a solution containing a known antigen or antibody. If the patient has antibodies or antigens that correspond to the added reagent, they will bind and form a visible precipitate. The size and density of the precipitate can be used to quantify the amount of antibody or antigen present in the sample.

Precipitin tests are commonly used in the diagnosis of various infectious diseases, autoimmune disorders, and allergies. They can also be used in forensic science to identify biological samples. However, they have largely been replaced by more modern immunological techniques such as enzyme-linked immunosorbent assays (ELISAs) and radioimmunoassays (RIAs).

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.

Platelet Factor 3 (PF3) is not a separate protein entity but rather refers to the complex formed when platelets are activated and expose their inner membrane, specifically a phospholipid-rich granule called the granule membrane particle, to the outside. This complex of platelet membrane with coagulation factors then serves as a catalytic surface for the acceleration of thrombin formation in the coagulation cascade.

In other words, PF3 is a part of the activated platelet's surface that plays an important role in blood clotting by promoting the conversion of prothrombin to thrombin and the subsequent fibrin formation, which helps to strengthen the clot.

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

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

Examples of recombinant fusion proteins include:

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

A point mutation is a type of genetic mutation where a single nucleotide base (A, T, C, or G) in DNA is altered, deleted, or substituted with another nucleotide. Point mutations can have various effects on the organism, depending on the location of the mutation and whether it affects the function of any genes. Some point mutations may not have any noticeable effect, while others might lead to changes in the amino acids that make up proteins, potentially causing diseases or altering traits. Point mutations can occur spontaneously due to errors during DNA replication or be inherited from parents.

A mesylate is a salt formed when mesylic acid (methanesulfonic acid) reacts with a base. In the context of pharmaceuticals, many drugs are available in mesylate form as it can be more soluble and bioavailable than other forms. Mesylates are commonly used to improve the absorption and effectiveness of medications.

For example, a drug called atenolol (a beta blocker used to treat high blood pressure) is often formulated as atenolol mesylate because the mesylate form is more soluble in water than the free base form, making it easier for the body to absorb and utilize the medication.

It's important to note that mesylates are not a specific medical condition or disease, but rather a type of pharmaceutical preparation.

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.

Amino acids are organic compounds that serve as the building blocks of proteins. They consist of a central carbon atom, also known as the alpha carbon, which is bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom (H), and a variable side chain (R group). The R group can be composed of various combinations of atoms such as hydrogen, oxygen, sulfur, nitrogen, and carbon, which determine the unique properties of each amino acid.

There are 20 standard amino acids that are encoded by the genetic code and incorporated into proteins during translation. These include:

1. Alanine (Ala)
2. Arginine (Arg)
3. Asparagine (Asn)
4. Aspartic acid (Asp)
5. Cysteine (Cys)
6. Glutamine (Gln)
7. Glutamic acid (Glu)
8. Glycine (Gly)
9. Histidine (His)
10. Isoleucine (Ile)
11. Leucine (Leu)
12. Lysine (Lys)
13. Methionine (Met)
14. Phenylalanine (Phe)
15. Proline (Pro)
16. Serine (Ser)
17. Threonine (Thr)
18. Tryptophan (Trp)
19. Tyrosine (Tyr)
20. Valine (Val)

Additionally, there are several non-standard or modified amino acids that can be incorporated into proteins through post-translational modifications, such as hydroxylation, methylation, and phosphorylation. These modifications expand the functional diversity of proteins and play crucial roles in various cellular processes.

Amino acids are essential for numerous biological functions, including protein synthesis, enzyme catalysis, neurotransmitter production, energy metabolism, and immune response regulation. Some amino acids can be synthesized by the human body (non-essential), while others must be obtained through dietary sources (essential).

Chymotrypsin is a proteolytic enzyme, specifically a serine protease, that is produced in the pancreas and secreted into the small intestine as an inactive precursor called chymotrypsinogen. Once activated, chymotrypsin helps to digest proteins in food by breaking down specific peptide bonds in protein molecules. Its activity is based on the recognition of large hydrophobic side chains in amino acids like phenylalanine, tryptophan, and tyrosine. Chymotrypsin plays a crucial role in maintaining normal digestion and absorption processes in the human body.

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.

Fibronectin receptors are a type of cell surface adhesion molecule that bind to the extracellular matrix protein fibronectin. These receptors are composed of transmembrane glycoproteins called integrins, which consist of non-covalently associated α and β subunits. The binding of fibronectin to its receptor triggers a range of intracellular signaling events that regulate various cellular functions, including cell adhesion, migration, proliferation, differentiation, and survival.

Fibronectin receptors play critical roles in many physiological processes, such as embryonic development, tissue repair, and hemostasis. They also contribute to the pathogenesis of various diseases, including fibrosis, cancer, and cardiovascular disease. In cancer, for example, increased expression of fibronectin receptors has been associated with tumor progression, metastasis, and drug resistance. Therefore, targeting fibronectin receptors has emerged as a promising therapeutic strategy for treating various diseases.

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.

Serotonin, also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter that is found primarily in the gastrointestinal (GI) tract, blood platelets, and the central nervous system (CNS) of humans and other animals. It is produced by the conversion of the amino acid tryptophan to 5-hydroxytryptophan (5-HTP), and then to serotonin.

In the CNS, serotonin plays a role in regulating mood, appetite, sleep, memory, learning, and behavior, among other functions. It also acts as a vasoconstrictor, helping to regulate blood flow and blood pressure. In the GI tract, it is involved in peristalsis, the contraction and relaxation of muscles that moves food through the digestive system.

Serotonin is synthesized and stored in serotonergic neurons, which are nerve cells that use serotonin as their primary neurotransmitter. These neurons are found throughout the brain and spinal cord, and they communicate with other neurons by releasing serotonin into the synapse, the small gap between two neurons.

Abnormal levels of serotonin have been linked to a variety of disorders, including depression, anxiety, schizophrenia, and migraines. Medications that affect serotonin levels, such as selective serotonin reuptake inhibitors (SSRIs), are commonly used to treat these conditions.

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

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

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

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

An acute disease is a medical condition that has a rapid onset, develops quickly, and tends to be short in duration. Acute diseases can range from minor illnesses such as a common cold or flu, to more severe conditions such as pneumonia, meningitis, or a heart attack. These types of diseases often have clear symptoms that are easy to identify, and they may require immediate medical attention or treatment.

Acute diseases are typically caused by an external agent or factor, such as a bacterial or viral infection, a toxin, or an injury. They can also be the result of a sudden worsening of an existing chronic condition. In general, acute diseases are distinct from chronic diseases, which are long-term medical conditions that develop slowly over time and may require ongoing management and treatment.

Examples of acute diseases include:

* Acute bronchitis: a sudden inflammation of the airways in the lungs, often caused by a viral infection.
* Appendicitis: an inflammation of the appendix that can cause severe pain and requires surgical removal.
* Gastroenteritis: an inflammation of the stomach and intestines, often caused by a viral or bacterial infection.
* Migraine headaches: intense headaches that can last for hours or days, and are often accompanied by nausea, vomiting, and sensitivity to light and sound.
* Myocardial infarction (heart attack): a sudden blockage of blood flow to the heart muscle, often caused by a buildup of plaque in the coronary arteries.
* Pneumonia: an infection of the lungs that can cause coughing, chest pain, and difficulty breathing.
* Sinusitis: an inflammation of the sinuses, often caused by a viral or bacterial infection.

It's important to note that while some acute diseases may resolve on their own with rest and supportive care, others may require medical intervention or treatment to prevent complications and promote recovery. If you are experiencing symptoms of an acute disease, it is always best to seek medical attention to ensure proper diagnosis and treatment.

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

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

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

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

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

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.

Leucine is an essential amino acid, meaning it cannot be produced by the human body and must be obtained through the diet. It is one of the three branched-chain amino acids (BCAAs), along with isoleucine and valine. Leucine is critical for protein synthesis and muscle growth, and it helps to regulate blood sugar levels, promote wound healing, and produce growth hormones.

Leucine is found in various food sources such as meat, dairy products, eggs, and certain plant-based proteins like soy and beans. It is also available as a dietary supplement for those looking to increase their intake for athletic performance or muscle recovery purposes. However, it's important to consult with a healthcare professional before starting any new supplement regimen.

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

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

There are two main types of isoantibodies:

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

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

Immunologic receptors are specialized proteins found on the surface of immune cells that recognize and bind to specific molecules, known as antigens, on the surface of pathogens or infected cells. This binding triggers a series of intracellular signaling events that activate the immune cell and initiate an immune response.

There are several types of immunologic receptors, including:

1. T-cell receptors (TCRs): These receptors are found on the surface of T cells and recognize antigens presented in the context of major histocompatibility complex (MHC) molecules.
2. B-cell receptors (BCRs): These receptors are found on the surface of B cells and recognize free antigens in solution.
3. Pattern recognition receptors (PRRs): These receptors are found inside immune cells and recognize conserved molecular patterns associated with pathogens, such as lipopolysaccharides and flagellin.
4. Fc receptors: These receptors are found on the surface of various immune cells and bind to the constant region of antibodies, mediating effector functions such as phagocytosis and antibody-dependent cellular cytotoxicity (ADCC).

Immunologic receptors play a critical role in the recognition and elimination of pathogens and infected cells, and dysregulation of these receptors can lead to immune disorders and diseases.

Erythroblastic Leukemia, Acute (also known as Acute Erythroid Leukemia or AEL) is a subtype of acute myeloid leukemia (AML), which is a type of cancer affecting the blood and bone marrow. In this condition, there is an overproduction of erythroblasts (immature red blood cells) in the bone marrow, leading to their accumulation and interference with normal blood cell production. This results in a decrease in the number of functional red blood cells, white blood cells, and platelets in the body. Symptoms may include fatigue, weakness, frequent infections, and easy bruising or bleeding. AEL is typically treated with chemotherapy and sometimes requires stem cell transplantation.

Hirudin is not a medical term itself, but it is a specific substance with medical relevance. Hirudin is a naturally occurring anticoagulant that is found in the saliva of certain species of leeches (such as Hirudo medicinalis). This compound works by inhibiting the activity of thrombin, a key enzyme in the coagulation cascade, which ultimately results in preventing blood clot formation.

Medically, hirudin has been used in some research and therapeutic settings for its anticoagulant properties. For instance, recombinant hirudin (also known as lepirudin) is available for clinical use as an injectable anticoagulant to treat or prevent blood clots in specific medical conditions, such as heparin-induced thrombocytopenia (HIT).

In summary, Hirudins are a group of anticoagulant substances, primarily derived from leeches, that inhibit the activity of thrombin and have potential medical applications in preventing or treating blood clots.

Glycoprotein hormones are a group of hormones that share a similar structure and are made up of four subunits: two identical alpha subunits and two distinct beta subunits. The alpha subunit is common to all glycoprotein hormones, including thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), and human chorionic gonadotropin (hCG).

The alpha subunit of glycoprotein hormones is a 92 amino acid polypeptide chain that contains several disulfide bonds, which help to stabilize its structure. It is heavily glycosylated, meaning that it contains many carbohydrate groups attached to the protein backbone. The alpha subunit plays an important role in the biological activity of the hormone by interacting with a specific receptor on the target cell surface.

The alpha subunit contains several regions that are important for its function, including a signal peptide, a variable region, and a conserved region. The signal peptide is a short sequence of amino acids at the N-terminus of the protein that directs it to the endoplasmic reticulum for processing and secretion. The variable region contains several amino acid residues that differ between different glycoprotein hormones, while the conserved region contains amino acids that are identical or very similar in all glycoprotein hormones.

Together with the beta subunit, the alpha subunit forms the functional hormone molecule. The beta subunit determines the specificity of the hormone for its target cells and regulates its biological activity.

Sepharose is not a medical term itself, but it is a trade name for a type of gel that is often used in medical and laboratory settings. Sepharose is a type of cross-linked agarose gel, which is derived from seaweed. It is commonly used in chromatography, a technique used to separate and purify different components of a mixture based on their physical or chemical properties.

Sepharose gels are available in various forms, including beads and sheets, and they come in different sizes and degrees of cross-linking. These variations allow for the separation and purification of molecules with different sizes, charges, and other properties. Sepharose is known for its high porosity, mechanical stability, and low non-specific binding, making it a popular choice for many laboratory applications.

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.

Combination drug therapy is a treatment approach that involves the use of multiple medications with different mechanisms of action to achieve better therapeutic outcomes. This approach is often used in the management of complex medical conditions such as cancer, HIV/AIDS, and cardiovascular diseases. The goal of combination drug therapy is to improve efficacy, reduce the risk of drug resistance, decrease the likelihood of adverse effects, and enhance the overall quality of life for patients.

In combining drugs, healthcare providers aim to target various pathways involved in the disease process, which may help to:

1. Increase the effectiveness of treatment by attacking the disease from multiple angles.
2. Decrease the dosage of individual medications, reducing the risk and severity of side effects.
3. Slow down or prevent the development of drug resistance, a common problem in chronic diseases like HIV/AIDS and cancer.
4. Improve patient compliance by simplifying dosing schedules and reducing pill burden.

Examples of combination drug therapy include:

1. Antiretroviral therapy (ART) for HIV treatment, which typically involves three or more drugs from different classes to suppress viral replication and prevent the development of drug resistance.
2. Chemotherapy regimens for cancer treatment, where multiple cytotoxic agents are used to target various stages of the cell cycle and reduce the likelihood of tumor cells developing resistance.
3. Cardiovascular disease management, which may involve combining medications such as angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, diuretics, and statins to control blood pressure, heart rate, fluid balance, and cholesterol levels.
4. Treatment of tuberculosis, which often involves a combination of several antibiotics to target different aspects of the bacterial life cycle and prevent the development of drug-resistant strains.

When prescribing combination drug therapy, healthcare providers must carefully consider factors such as potential drug interactions, dosing schedules, adverse effects, and contraindications to ensure safe and effective treatment. Regular monitoring of patients is essential to assess treatment response, manage side effects, and adjust the treatment plan as needed.

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.

Purinergic P2Y12 receptors are a type of G protein-coupled receptor that bind to and are activated by adenosine diphosphate (ADP). These receptors play an important role in regulating platelet activation and aggregation, which is crucial for the normal hemostatic response to vascular injury.

The P2Y12 receptor is a key component of the platelet signaling pathway that leads to the activation of integrin αIIbβ3, which mediates platelet aggregation. Inhibition of the P2Y12 receptor with drugs such as clopidogrel or ticagrelor is a standard treatment for preventing thrombosis in patients at risk of arterial occlusion, such as those with acute coronary syndrome or following percutaneous coronary intervention.

P2Y12 receptors are also expressed on other cell types, including immune cells and neurons, where they play roles in inflammation, neurotransmission, and other physiological processes.

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

Contractile proteins are a type of protein found in muscle cells that are responsible for the ability of the muscle to contract and generate force. The two main types of contractile proteins are actin and myosin, which are arranged in sarcomeres, the functional units of muscle fibers. When stimulated by a nerve impulse, actin and myosin filaments slide past each other, causing the muscle to shorten and generate force. This process is known as excitation-contraction coupling. Other proteins, such as tropomyosin and troponin, regulate the interaction between actin and myosin and control muscle contraction.

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

Acetates, in a medical context, most commonly refer to compounds that contain the acetate group, which is an functional group consisting of a carbon atom bonded to two hydrogen atoms and an oxygen atom (-COO-). An example of an acetate is sodium acetate (CH3COONa), which is a salt formed from acetic acid (CH3COOH) and is often used as a buffering agent in medical solutions.

Acetates can also refer to a group of medications that contain acetate as an active ingredient, such as magnesium acetate, which is used as a laxative, or calcium acetate, which is used to treat high levels of phosphate in the blood.

In addition, acetates can also refer to a process called acetylation, which is the addition of an acetyl group (-COCH3) to a molecule. This process can be important in the metabolism and regulation of various substances within the body.

Oligosaccharides are complex carbohydrates composed of relatively small numbers (3-10) of monosaccharide units joined together by glycosidic linkages. They occur naturally in foods such as milk, fruits, vegetables, and legumes. In the body, oligosaccharides play important roles in various biological processes, including cell recognition, signaling, and protection against pathogens.

There are several types of oligosaccharides, classified based on their structures and functions. Some common examples include:

1. Disaccharides: These consist of two monosaccharide units, such as sucrose (glucose + fructose), lactose (glucose + galactose), and maltose (glucose + glucose).
2. Trisaccharides: These contain three monosaccharide units, like maltotriose (glucose + glucose + glucose) and raffinose (galactose + glucose + fructose).
3. Oligosaccharides found in human milk: Human milk contains unique oligosaccharides that serve as prebiotics, promoting the growth of beneficial bacteria in the gut. These oligosaccharides also help protect infants from pathogens by acting as decoy receptors and inhibiting bacterial adhesion to intestinal cells.
4. N-linked and O-linked glycans: These are oligosaccharides attached to proteins in the body, playing crucial roles in protein folding, stability, and function.
5. Plant-derived oligosaccharides: Fructooligosaccharides (FOS) and galactooligosaccharides (GOS) are examples of plant-derived oligosaccharides that serve as prebiotics, promoting the growth of beneficial gut bacteria.

Overall, oligosaccharides have significant impacts on human health and disease, particularly in relation to gastrointestinal function, immunity, and inflammation.

Scanning electron microscopy (SEM) is a type of electron microscopy that uses a focused beam of electrons to scan the surface of a sample and produce a high-resolution image. In SEM, a beam of electrons is scanned across the surface of a specimen, and secondary electrons are emitted from the sample due to interactions between the electrons and the atoms in the sample. These secondary electrons are then detected by a detector and used to create an image of the sample's surface topography. SEM can provide detailed images of the surface of a wide range of materials, including metals, polymers, ceramics, and biological samples. It is commonly used in materials science, biology, and electronics for the examination and analysis of surfaces at the micro- and nanoscale.

Cytoplasmic granules are small, membrane-bound organelles or inclusions found within the cytoplasm of cells. They contain various substances such as proteins, lipids, carbohydrates, and genetic material. Cytoplasmic granules have diverse functions depending on their specific composition and cellular location. Some examples include:

1. Secretory granules: These are found in secretory cells and store hormones, neurotransmitters, or enzymes before they are released by exocytosis.
2. Lysosomes: These are membrane-bound organelles that contain hydrolytic enzymes for intracellular digestion of waste materials, foreign substances, and damaged organelles.
3. Melanosomes: Found in melanocytes, these granules produce and store the pigment melanin, which is responsible for skin, hair, and eye color.
4. Weibel-Palade bodies: These are found in endothelial cells and store von Willebrand factor and P-selectin, which play roles in hemostasis and inflammation.
5. Peroxisomes: These are single-membrane organelles that contain enzymes for various metabolic processes, such as β-oxidation of fatty acids and detoxification of harmful substances.
6. Lipid bodies (also called lipid droplets): These are cytoplasmic granules that store neutral lipids, such as triglycerides and cholesteryl esters. They play a role in energy metabolism and intracellular signaling.
7. Glycogen granules: These are cytoplasmic inclusions that store glycogen, a polysaccharide used for energy storage in animals.
8. Protein bodies: Found in plants, these granules store excess proteins and help regulate protein homeostasis within the cell.
9. Electron-dense granules: These are found in certain immune cells, such as mast cells and basophils, and release mediators like histamine during an allergic response.
10. Granules of unknown composition or function may also be present in various cell types.

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

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

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

Atherectomy, coronary, is a medical procedure used to treat narrowed or blocked coronary arteries due to the buildup of plaque (atherosclerosis). The goal of coronary atherectomy is to improve blood flow to the heart muscle by removing the obstructive material within the vessel.

During the procedure, a specialized catheter with a cutting device on its tip is inserted into a peripheral artery, usually in the groin or arm, and advanced to the affected coronary artery. The cutting device can be a rotating blade, a high-speed spinning burr, or a laser fiber that is used to shave, drill, or vaporize the plaque, respectively. The removed material is collected in a chamber within the catheter or washed away by blood flow.

There are different types of coronary atherectomy devices, including:

1. Directional atherectomy (DCA): A rotating blade cuts and removes the plaque in a targeted direction.
2. Rotational atherectomy (Rotablator): A high-speed spinning burr is used to abrade and pulverize the plaque into tiny particles that can be safely carried away by blood flow.
3. Laser atherectomy: A laser fiber is used to vaporize or break down the plaque into gaseous or small particle form.

Coronary atherectomy is typically performed in conjunction with angioplasty and stenting, as it helps prepare the narrowed artery for these procedures by creating a larger lumen and reducing the risk of complications like dissections or restenosis (re-narrowing). However, its use may be limited to specific cases due to the potential risks, such as vessel trauma, distal embolization, or perforation.

It is essential to consult with a medical professional for detailed information and personalized treatment recommendations regarding coronary atherectomy.

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

Platelet Storage Pool Deficiency (PSPD) is a group of bleeding disorders characterized by a decrease in the number or function of secretory granules (storage pools) in platelets, which are small blood cells that play a crucial role in clotting. These granules contain various substances such as ADP (adenosine diphosphate), ATP (adenosine triphosphate), calcium ions, and serotonin, which are released during platelet activation to help promote clot formation.

In PSPD, the quantitative or qualitative deficiency of these granules leads to impaired platelet function and increased bleeding tendency. The condition can be inherited or acquired, and it is often classified based on the type of granule affected: dense granules (delta granules) or alpha granules.

Delta granule deficiency, also known as Dense Granule Deficiency (DGD), results in decreased levels of ADP, ATP, and calcium ions, while alpha granule deficiency leads to reduced levels of von Willebrand factor, fibrinogen, and other clotting factors.

Symptoms of PSPD can vary from mild to severe and may include easy bruising, prolonged bleeding after injury or surgery, nosebleeds, and gum bleeding. The diagnosis typically involves platelet function tests, electron microscopy, and genetic testing. Treatment options depend on the severity of the condition and may include desmopressin (DDAVP), platelet transfusions, or other medications to manage bleeding symptoms.

Fibrinolysin is defined as a proteolytic enzyme that dissolves or breaks down fibrin, a protein involved in the clotting of blood. This enzyme is produced by certain cells, such as endothelial cells that line the interior surface of blood vessels, and is an important component of the body's natural mechanism for preventing excessive blood clotting and maintaining blood flow.

Fibrinolysin works by cleaving specific bonds in the fibrin molecule, converting it into soluble degradation products that can be safely removed from the body. This process is known as fibrinolysis, and it helps to maintain the balance between clotting and bleeding in the body.

In medical contexts, fibrinolysin may be used as a therapeutic agent to dissolve blood clots that have formed in the blood vessels, such as those that can occur in deep vein thrombosis or pulmonary embolism. It is often administered in combination with other medications that help to enhance its activity and specificity for fibrin.

Intravenous (IV) infusion is a medical procedure in which liquids, such as medications, nutrients, or fluids, are delivered directly into a patient's vein through a needle or a catheter. This route of administration allows for rapid absorption and distribution of the infused substance throughout the body. IV infusions can be used for various purposes, including resuscitation, hydration, nutrition support, medication delivery, and blood product transfusion. The rate and volume of the infusion are carefully controlled to ensure patient safety and efficacy of treatment.

Post-translational protein processing refers to the modifications and changes that proteins undergo after their synthesis on ribosomes, which are complex molecular machines responsible for protein synthesis. These modifications occur through various biochemical processes and play a crucial role in determining the final structure, function, and stability of the protein.

The process begins with the translation of messenger RNA (mRNA) into a linear polypeptide chain, which is then subjected to several post-translational modifications. These modifications can include:

1. Proteolytic cleavage: The removal of specific segments or domains from the polypeptide chain by proteases, resulting in the formation of mature, functional protein subunits.
2. Chemical modifications: Addition or modification of chemical groups to the side chains of amino acids, such as phosphorylation (addition of a phosphate group), glycosylation (addition of sugar moieties), methylation (addition of a methyl group), acetylation (addition of an acetyl group), and ubiquitination (addition of a ubiquitin protein).
3. Disulfide bond formation: The oxidation of specific cysteine residues within the polypeptide chain, leading to the formation of disulfide bonds between them. This process helps stabilize the three-dimensional structure of proteins, particularly in extracellular environments.
4. Folding and assembly: The acquisition of a specific three-dimensional conformation by the polypeptide chain, which is essential for its function. Chaperone proteins assist in this process to ensure proper folding and prevent aggregation.
5. Protein targeting: The directed transport of proteins to their appropriate cellular locations, such as the nucleus, mitochondria, endoplasmic reticulum, or plasma membrane. This is often facilitated by specific signal sequences within the protein that are recognized and bound by transport machinery.

Collectively, these post-translational modifications contribute to the functional diversity of proteins in living organisms, allowing them to perform a wide range of cellular processes, including signaling, catalysis, regulation, and structural support.

Thrombopoiesis is the process of formation and development of thrombocytes or platelets, which are small, colorless cell fragments in our blood that play an essential role in clotting. Thrombopoiesis occurs inside the bone marrow, where stem cells differentiate into megakaryoblasts, then progressively develop into promegakaryocytes and megakaryocytes. These megakaryocytes subsequently undergo a process called cytoplasmic fragmentation to produce platelets.

The regulation of thrombopoiesis is primarily controlled by the hormone thrombopoietin (TPO), which is produced mainly in the liver and binds to the thrombopoietin receptor (c-Mpl) on megakaryocytes and their precursors. This binding stimulates the proliferation, differentiation, and maturation of megakaryocytes, leading to an increase in platelet production.

Abnormalities in thrombopoiesis can result in conditions such as thrombocytopenia (low platelet count) or thrombocytosis (high platelet count), which may be associated with bleeding disorders or increased risk of thrombosis, respectively.

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.

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

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

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

Thrombopoietin (TPO) is a glycoprotein hormone that plays a crucial role in the regulation of platelet production, also known as thrombopoiesis. It is primarily produced by the liver and to some extent by megakaryocytes, which are the cells responsible for producing platelets.

TPO binds to its receptor, c-Mpl, on the surface of megakaryocytes and their precursor cells, stimulating their proliferation, differentiation, and maturation into platelets. By regulating the number of platelets in circulation, TPO helps maintain hemostasis, the process that prevents excessive bleeding after injury.

In addition to its role in thrombopoiesis, TPO has been shown to have potential effects on other cell types, including hematopoietic stem cells and certain immune cells. However, its primary function remains the regulation of platelet production.

Myelin-Oligodendrocyte Glycoprotein (MOG) is a protein found exclusively on the outermost layer of myelin sheath in the central nervous system (CNS). The myelin sheath is a fatty substance that surrounds and insulates nerve fibers, allowing for efficient and rapid transmission of electrical signals. MOG plays a crucial role in maintaining the integrity and structure of the myelin sheath. It is involved in the adhesion of oligodendrocytes to the surface of neuronal axons and contributes to the stability of the compact myelin structure. Autoimmune reactions against MOG have been implicated in certain inflammatory demyelinating diseases, such as optic neuritis, transverse myelitis, and acute disseminated encephalomyelitis (ADEM).

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

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

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

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

Cytoplasm is the material within a eukaryotic cell (a cell with a true nucleus) that lies between the nuclear membrane and the cell membrane. It is composed of an aqueous solution called cytosol, in which various organelles such as mitochondria, ribosomes, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles are suspended. Cytoplasm also contains a variety of dissolved nutrients, metabolites, ions, and enzymes that are involved in various cellular processes such as metabolism, signaling, and transport. It is where most of the cell's metabolic activities take place, and it plays a crucial role in maintaining the structure and function of the cell.

Apyrase is an enzyme that catalyzes the hydrolysis of nucleoside triphosphates (like ATP or GTP) to nucleoside diphosphates (like ADP or GDP), releasing inorganic phosphate in the process. It can also hydrolyze nucleoside diphosphates to nucleoside monophosphates, releasing inorganic pyrophosphate.

This enzyme is widely distributed in nature and has been found in various organisms, including bacteria, plants, and animals. In humans, apyrases are present in different tissues, such as the brain, platelets, and red blood cells. They play essential roles in several biological processes, including signal transduction, metabolism regulation, and inflammatory response modulation.

There are two major classes of apyrases: type I (also known as nucleoside diphosphate kinase) and type II (also known as NTPDase). Type II apyrases have higher substrate specificity for nucleoside triphosphates, while type I apyrases can hydrolyze both nucleoside tri- and diphosphates.

In the medical field, apyrases are sometimes used in research to study platelet function or neurotransmission, as they can help regulate purinergic signaling by controlling extracellular levels of ATP and ADP. Additionally, some studies suggest that apyrase activity might be involved in certain pathological conditions, such as atherosclerosis, thrombosis, and neurological disorders.

Fibronectin is a high molecular weight glycoprotein that is found in many tissues and body fluids, including plasma, connective tissue, and the extracellular matrix. It is composed of two similar subunits that are held together by disulfide bonds. Fibronectin plays an important role in cell adhesion, migration, and differentiation by binding to various cell surface receptors, such as integrins, and other extracellular matrix components, such as collagen and heparan sulfate proteoglycans.

Fibronectin has several isoforms that are produced by alternative splicing of a single gene transcript. These isoforms differ in their biological activities and can be found in different tissues and developmental stages. Fibronectin is involved in various physiological processes, such as wound healing, tissue repair, and embryonic development, and has been implicated in several pathological conditions, including fibrosis, tumor metastasis, and thrombosis.

Prothrombin is a protein present in blood plasma, and it's also known as coagulation factor II. It plays a crucial role in the coagulation cascade, which is a complex series of reactions that leads to the formation of a blood clot.

When an injury occurs, the coagulation cascade is initiated to prevent excessive blood loss. Prothrombin is converted into its active form, thrombin, by another factor called factor Xa in the presence of calcium ions, phospholipids, and factor Va. Thrombin then catalyzes the conversion of fibrinogen into fibrin, forming a stable clot.

Prothrombin levels can be measured through a blood test, which is often used to diagnose or monitor conditions related to bleeding or coagulation disorders, such as liver disease or vitamin K deficiency.

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

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

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

Epitope mapping is a technique used in immunology to identify the specific portion or regions (called epitopes) on an antigen that are recognized and bind to antibodies or T-cell receptors. This process helps to understand the molecular basis of immune responses against various pathogens, allergens, or transplanted tissues.

Epitope mapping can be performed using different methods such as:

1. Peptide scanning: In this method, a series of overlapping peptides spanning the entire length of the antigen are synthesized and tested for their ability to bind to antibodies or T-cell receptors. The peptide that shows binding is considered to contain the epitope.
2. Site-directed mutagenesis: In this approach, specific amino acids within the antigen are altered, and the modified antigens are tested for their ability to bind to antibodies or T-cell receptors. This helps in identifying the critical residues within the epitope.
3. X-ray crystallography and NMR spectroscopy: These techniques provide detailed information about the three-dimensional structure of antigen-antibody complexes, allowing for accurate identification of epitopes at an atomic level.

The results from epitope mapping can be useful in various applications, including vaccine design, diagnostic test development, and understanding the basis of autoimmune diseases.

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

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

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

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

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

... platelet glycoprotein gpib-ix complex MeSH D12.776.395.550.625.785 - platelet glycoprotein gpiib-iiia complex MeSH D12.776. ... platelet glycoprotein gpib-ix complex MeSH D12.776.395.550.625.800.790 - receptor, par-1 MeSH D12.776.395.550.625.800.800 - ... p-glycoproteins MeSH D12.776.395.550.020.610.610 - p-glycoprotein MeSH D12.776.395.550.200.065 - antigens, cd22 MeSH D12.776. ... This list covers glycoproteins. For other protein-related codes, see List of MeSH codes (D12.776). Codes before these are found ...
... platelet glycoprotein gpib-ix complex MeSH D12.776.543.750.705.675.784 - platelet glycoprotein gpiib-iiia complex MeSH D12.776. ... platelet glycoprotein gpib-ix complex MeSH D12.776.543.550.625.785 - platelet glycoprotein gpiib-iiia complex MeSH D12.776. ... platelet glycoprotein gpiib-iiia complex MeSH D12.776.543.750.705.408.460.870 - receptors, vitronectin MeSH D12.776.543.750. ... platelet glycoprotein gpib-ix complex MeSH D12.776.543.550.625.800.790 - receptor, par-1 MeSH D12.776.543.550.625.800.800 - ...
Platelet aggregation is achieved by mediating expression of the glycoprotein complex GP IIb/IIIa in the cell membrane of ... Thromboxane A2 (TXA2), produced by activated platelets, has prothrombotic properties, stimulating activation of new platelets ... If the cap of a vulnerable plaque erodes or ruptures, as in myocardial infarction, platelets stick to the damaged lining of the ... The mechanism of secretion of thromboxanes from platelets is still unclear. They act in the formation of blood clots and reduce ...
... the platelets are joined by vWF due to its ability to bind the activated GPIIb / IIIa complex. This transmembrane glycoprotein ... Changes in the platelet membrane glycoprotein IIb.IIIa complex during platelet activation. The Journal of Biological Chemistry ... The IIb / IIIa complex is a major platelet membrane component. There are as many as 50 000 copies. The αIIb (GPIIb) is composed ... In consequence, this complex activates GPIIb / IIIa membrane glycoproteins, allowing them to bind fibrinogen. Fibrinogen ...
The GPIIb/IIIa antagonist blocks the binding of fibrinogen to the GPIIb/IIIa receptors, preventing the formation of platelet- ... Ristocetin forms complexes with von Willebrand factor (vWF) that bind to the glycoprotein Ib (GP1b) receptors on platelets, ... Binding of fibrinogen to GPIIb/IIIa receptors leads to platelet-to-platelet bridges and results in platelet aggregation. ... Activation also induces a conformational change in the glycoprotein IIb/IIIa (GPIIb/IIIa) receptor, giving it high affinity for ...
The complete receptor complex includes noncovalent association of the alpha and beta subunits with platelet glycoprotein IX ( ... and GPIIb/IIIa are implicated in expression of thrombin-induced platelet procoagulant activity". Thromb. Haemost. 86 (4): 1065- ... "Interaction of platelet glycoprotein V with glycoprotein Ib-IX regulates expression of the glycoproteins and binding of von ... Human platelet glycoprotein V (GP5) is a part of the Ib-V-IX system of surface glycoproteins that constitute the receptor for ...
... is rich in glycoproteins required for platelet adhesion, activation and aggregation. For example, GPIb/IX/V; GPVI; GPIIb/IIIa. ... This process is complex, as more than 193 proteins and 301 interactions are known to be involved in platelet dynamics. While ... activated platelets with exposed GPIIb/IIIa can bind fibrinogen to aggregate. GPIIb/IIIa may also further anchor the platelets ... Platelets also secrete platelet-derived growth factor (PDGF). Platelets modulate neutrophils by forming platelet-leukocyte ...
The use of cytochalasin is more favorable than using glycoprotein IIb/ IIIa inhibitors which block platelet incompletely, ... and only supratherapeutic doses of GPIIb/IIIa antagonists may influence results. The sensitivity for coagulation factor ... Moreover, it is successfully used in the complex situation of (poly)trauma, or in decision making for of alternative therapy ... FIBTEM eliminates the platelet contribution of clot formation by inhibiting the platelets irreversibly with cytochalasin D, a ...
GPIIb/IIIa), which is the most abundant platelet surface receptor. Despite the high shear stress at the thrombus area, the ... If microbubbles are targeted with ligands that bind receptors like VEGF or activated glycoprotein IIb/IIIa, they can non- ... This may be the surface of a small air bubble or a more complex structure. Commercially available contrast media are gas-filled ... GPIIb/IIIa-targeted microbubbles will specifically bind to activated platelets and allow real-time molecular imaging of ...
... blood platelets through binding to their GpIIb/IIIa surface membrane fibrinogen receptor. Fibrin participates in limiting blood ... Fibrinogen (factor I) is a glycoprotein complex, produced in the liver, that circulates in the blood of all vertebrates. During ... are now known to take up and store but not make the glycoprotein. The final secreted, hepatocyte-derived glycoprotein is ... The fibrinogen molecule circulates as a soluble plasma glycoprotein with a typical molecular weight of ~340-~420 kDa (kilo- ...
D3 phosphoinositides and outside-in integrin signaling by GPIIb/IIIa mediate platelet actin assembly and filopodial extension ... Localization of the domain actin-binding protein that binds to glycoprotein Ib and actin in human platelets. J Biol Chem. 1988 ... 2002; Importance of free actin filament barbed ends for Arp2/3 complex function in platelets and fibroblasts. Proc Nat Acad Sci ... Arp2/3 Complex-Deficient Mouse Fibroblasts are Viable and Have Normal Leading Edge Actin Structure and Function. 2005. Proc Nat ...
Platelet Glycoprotein GPIIb-IIIa Complex*Platelet Glycoprotein GPIIb-IIIa Complex. *Platelet Glycoprotein GPIIb IIIa Complex ... Platelet Membrane Glycoproteins [D12.776.543.750.705.675]. *Platelet Glycoprotein GPIIb-IIIa Complex [D12.776.543.750.705.675. ... "Platelet Glycoprotein GPIIb-IIIa Complex" by people in Harvard Catalyst Profiles by year, and whether "Platelet Glycoprotein ... "Platelet Glycoprotein GPIIb-IIIa Complex" is a descriptor in the National Library of Medicines controlled vocabulary thesaurus ...
Platelet Aggregation Inhibitors / therapeutic use* * Platelet Glycoprotein GPIIb-IIIa Complex / antagonists & inhibitors* ... The glycoprotein (GP) IIb/IIIa receptor inhibitors are even more effective in inhibiting platelet activation. Under what ... Management of intermediate coronary syndrome: role of conservative treatment, glycoprotein IIb/IIIa receptor inhibitors, and ...
... treatment with glycoprotein IIb/IIIa inhibitors (GPIs) should be limited to bail-out and/or highly thrombotic situations. ... Platelet Aggregation Inhibitors / therapeutic use * Platelet Glycoprotein GPIIb-IIIa Complex * Prasugrel Hydrochloride ... In the era of potent P2Y12 inhibitors, according to current guidelines, treatment with glycoprotein IIb/IIIa inhibitors (GPIs) ... Keywords: Antiplatelet therapy; Aspiration thrombectomy; Glycoprotein IIb/IIIa inhibitors; Myocardial infarction; Percutaneous ...
GPIIb-IIIa).. The most abundant glycoprotein on the platelet membrane is the GPIIb-IIIa complex. Inactivated platelets bind ... It binds to the platelet through the glycoprotein IIb/IIIa receptor and, therefore, is highly involved in the thrombotic ... Platelet GP IIIa PIA and GP Ib variable number tandem repeat polymorphism and markers of platelet activation in acute stroke. ... Platelets play an important role in the development of acute coronary syndromes. Platelets possess glycoprotein receptors on ...
... platelet glycoprotein gpib-ix complex MeSH D12.776.395.550.625.785 - platelet glycoprotein gpiib-iiia complex MeSH D12.776. ... platelet glycoprotein gpib-ix complex MeSH D12.776.395.550.625.800.790 - receptor, par-1 MeSH D12.776.395.550.625.800.800 - ... p-glycoproteins MeSH D12.776.395.550.020.610.610 - p-glycoprotein MeSH D12.776.395.550.200.065 - antigens, cd22 MeSH D12.776. ... This list covers glycoproteins. For other protein-related codes, see List of MeSH codes (D12.776). Codes before these are found ...
Platelet Membrane Glycoprotein IIb, Enoxaparin, Intention to Treat Analysis, Platelet Glycoprotein GPIIb-IIIa Complex ... However, not all patients in these trials received glycoprotein (GP) IIb/IIIa inhibitors. The A to Z trial is the first large, ... Prior statin or lipid-lowering therapy within prior six weeks, use of a GP IIb/IIIa inhibitor other than tirofiban within 24 ... randomized trial to examine the safety and efficacy of the combination of enoxaparin versus UFH with use of a GP IIb/IIIa ...
Platelet Glycoprotein GPIIb-IIIa Complex ... Radial access was used in 71%, and glycoprotein IIb/IIIa ... Bleeding was quite low, which may have been due to the high use of radial access and low use of glycoprotein IIb/IIIa ...
... activity of each protein is enough to support normal platelet aggregation. ... Glanzmann thrombasthenia is a genetic platelet disorder in which the platelet have qualitative or quantitative deficiencies of ... The platelet integrin αIIbβ3, also known as the glycoprotein GPIIb/IIIa (CD41/CD61) complex, is essential for normal platelet ... Adjacent platelets are cross-linked through the αIIβ3, resulting in platelet aggregation and hemostasis. When the complex ...
Platelet Glycoprotein GPIb-IX Complex [D09.400.430.890.625.460] * Platelet Glycoprotein GPIIb-IIIa Complex [D09.400.430.890. ... Platelet Glycoprotein GPIb-IX Complex [D12.776.395.550.625.460] * Platelet Glycoprotein GPIIb-IIIa Complex [D12.776.395.550. ... Platelet Glycoprotein GPIb-IX Complex [D12.776.543.550.625.460] * Platelet Glycoprotein GPIIb-IIIa Complex [D12.776.543.550. ... Platelet Glycoprotein GPIb-IX Complex [D12.776.543.750.705.675.568] * Platelet Glycoprotein GPIIb-IIIa Complex [D12.776.543.750 ...
Platelet Glycoprotein GPIIb-IIIa Complex 76% * Clopidogrel 25% * Percutaneous Coronary Intervention 21% ... Cangrelor With and Without Glycoprotein IIb/IIIa Inhibitors in Patients Undergoing Percutaneous Coronary Intervention. CHAMPION ... Platelet hyperactivity in acute myocardial infarction in man - Effects of prostacyclin. Mueller, H. S., Rao, P. S., Greenberg, ... Systemic and transcardiac platelet activity in acute myocardial infarction in man: Resistance to prostacyclin. Mueller, H. S., ...
Platelet Glycoprotein GPIIb-IIIa Complex. *Platelet Aggregation Inhibitors. *Middle Aged. *Male. *Immunoglobulin Fab Fragments ... Outcomes at 1 year and economic implications of platelet glycoprotein IIb/IIIa blockade in patients undergoing coronary ... "Outcomes at 1 year and economic implications of platelet glycoprotein IIb/IIIa blockade in patients undergoing coronary ... Outcomes at 1 year and economic implications of platelet glycoprotein IIb/IIIa blockade in patients undergoing coronary ...
Platelet Glycoprotein GPIIb-IIIa Complex. *Platelet Aggregation Inhibitors. *Myocardial Infarction. *Humans. *Hemorrhage ...
Platelet Glycoprotein GPIIb-IIIa Complex/metabolism, Protein Binding, Protein Kinase C/metabolism, Stimulation, Chemical, ...
Platelet Glycoprotein GPIIb-IIIa Complex 100% * Platelet Aggregation 79% * Blood Platelets 61% ... Advancing the battle against acute ischemic syndromes: A focus on the GP IIb-IIIa inhibitors. Dobesh, P. P. & Latham, K. A., ... Administration of glycoprotein IIb-IIIa inhibitors in patients with ST-segment elevation myocardial infarction. Dobesh, P. P. ... Platelet reactivity testing: An objective analysis of current capability. Oestreich, J. H. & Dobesh, P. P., 2011, In: Acute ...
Platelet Glycoprotein GPIIb-IIIa Complex 80% * Drug-Eluting Stents 75% * Stents 54% ... Outcomes of a preoperative "bridging" strategy with glycoprotein IIb/IIIa inhibitors to prevent perioperative stent thrombosis ...
... activity of each protein is enough to support normal platelet aggregation. ... Glanzmann thrombasthenia is a genetic platelet disorder in which the platelet have qualitative or quantitative deficiencies of ... The platelet integrin αIIbβ3, also known as the glycoprotein GPIIb/IIIa (CD41/CD61) complex, is essential for normal platelet ... Adjacent platelets are cross-linked through the αIIβ3, resulting in platelet aggregation and hemostasis. When the complex ...
Platelet Membrane Glycoproteins Medizin & Biologie 98% * Platelet Glycoprotein GPIIb-IIIa Complex Medizin & Biologie 88% ... Platelet inhibition and GP IIb/IIIa receptor occupancy by intracoronary versus intravenous bolus administration of abciximab in ... Platelet inhibition and GP IIb/IIIa receptor occupancy by intracoronary versus intravenous bolus administration of abciximab in ... Platelet inhibition and GP IIb/IIIa receptor occupancy by intracoronary versus intravenous bolus administration of abciximab in ...
Platelet Glycoprotein GPIIb-IIIa Complex Medicine & Life Sciences 9% View full fingerprint ... Low-molecular-weight heparins and platelet glycoprotein IIb/IIIa inhibitors have shown the potential to improve pharmacological ... Low-molecular-weight heparins and platelet glycoprotein IIb/IIIa inhibitors have shown the potential to improve pharmacological ... Low-molecular-weight heparins and platelet glycoprotein IIb/IIIa inhibitors have shown the potential to improve pharmacological ...
Platelet Glycoprotein GPIIb-IIIa Complex Medicine & Life Sciences 90% * Acute Coronary Syndrome Medicine & Life Sciences 71% ... T1 - Platelet glycoprotein IIb/IIIa inhibitors for acute coronary syndromes. T2 - Initiate treatment early or wait for the ... title = "Platelet glycoprotein IIb/IIIa inhibitors for acute coronary syndromes: Initiate treatment early or wait for the ... Platelet glycoprotein IIb/IIIa inhibitors for acute coronary syndromes: Initiate treatment early or wait for the ...
Platelet Glycoprotein GPIIb-IIIa Complex Medicine & Life Sciences 28% View full fingerprint ... together with recently reported severe bleeding events in some patients receiving oral platelet glycoprotein IIb/IIIa therapy, ... together with recently reported severe bleeding events in some patients receiving oral platelet glycoprotein IIb/IIIa therapy, ... together with recently reported severe bleeding events in some patients receiving oral platelet glycoprotein IIb/IIIa therapy, ...
Platelet Glycoprotein GPIIb-IIIa Complex Medicine & Life Sciences 76% * Clopidogrel Medicine & Life Sciences 25% ... Cangrelor With and Without Glycoprotein IIb/IIIa Inhibitors in Patients Undergoing Percutaneous Coronary Intervention. Journal ... Cangrelor With and Without Glycoprotein IIb/IIIa Inhibitors in Patients Undergoing Percutaneous Coronary Intervention. In: ... Dive into the research topics of Cangrelor With and Without Glycoprotein IIb/IIIa Inhibitors in Patients Undergoing ...
Platelet Glycoprotein GPIIb-IIIa Complex Medicine & Life Sciences 42% * Stroke Medicine & Life Sciences 22% ... Panel members preferred intravenous aspirin or, alternatively, a glycoprotein IIb/IIIa receptor inhibitor as an intraprocedural ... Panel members preferred intravenous aspirin or, alternatively, a glycoprotein IIb/IIIa receptor inhibitor as an intraprocedural ... Panel members preferred intravenous aspirin or, alternatively, a glycoprotein IIb/IIIa receptor inhibitor as an intraprocedural ...
Platelet Glycoprotein GPIIb-IIIa Complex Medicine & Life Sciences 88% * Percutaneous Coronary Intervention Medicine & Life ... Blockade of the platelet glycoprotein IIb/IIIa receptor by abciximab (c7E3 Fab) during coronary intervention reduces the ... Standard versus low-dose weight-adjusted heparin in patients treated with the platelet glycoprotein IIb/IIIa receptor antibody ... Standard versus low-dose weight-adjusted heparin in patients treated with the platelet glycoprotein IIb/IIIa receptor antibody ...
Platelet Glycoprotein GPIIb-IIIa Complex Platelet Glycoprotein GPIIb-IIIa Complex. FaCtor XIIIa Factor XIIIa. ...
Platelet Glycoprotein GPIIb-IIIa Complex Platelet Glycoprotein GPIIb-IIIa Complex. FaCtor XIIIa Factor XIIIa. ...
Platelet Glycoprotein GPIIb-IIIa Complex Platelet Glycoprotein GPIIb-IIIa Complex. FaCtor XIIIa Factor XIIIa. ...
Platelet Glycoprotein GPIIb-IIIa Complex Platelet Glycoprotein GPIIb-IIIa Complex. FaCtor XIIIa Factor XIIIa. ...
Platelet Glycoprotein GPIIb-IIIa Complex Platelet Glycoprotein GPIIb-IIIa Complex. FaCtor XIIIa Factor XIIIa. ...
Receptor complex and Platelet Glycoprotein GPIIb-IIIa Complex,. *Cell biology together with Integrin, Cell adhesion, Macrophage ... Engagement of Platelet Toll-Like Receptor 9 by Novel Endogenous Ligands Promotes Platelet Hyperreactivity and Thrombosis (99 ... Platelet CD36 links hyperlipidemia, oxidant stress and a prothrombotic phenotype. Eugene A Podrez;Tatiana V Byzova;Maria ...
  • The glycoprotein (GP) IIb/IIIa receptor inhibitors are even more effective in inhibiting platelet activation. (nih.gov)
  • In the era of potent P2Y 12 inhibitors, according to current guidelines, treatment with glycoprotein IIb/IIIa inhibitors (GPIs) should be limited to bail-out and/or highly thrombotic situations. (nih.gov)
  • However, not all patients in these trials received glycoprotein (GP) IIb/IIIa inhibitors. (acc.org)
  • Radial access was used in 71%, and glycoprotein IIb/IIIa inhibitors were used in fewer than 25% of patients who underwent percutaneous coronary intervention (PCI). (acc.org)
  • Bleeding was quite low, which may have been due to the high use of radial access and low use of glycoprotein IIb/IIIa inhibitors. (acc.org)
  • Low-molecular-weight heparins and platelet glycoprotein IIb/IIIa inhibitors have shown the potential to improve pharmacological reperfusion therapy. (nyu.edu)
  • Platelet glycoprotein IIb/IIIa inhibitors for acute coronary syndromes: Initiate treatment early or wait for the catheterization laboratory? (mssm.edu)
  • Dive into the research topics of 'Platelet glycoprotein IIb/IIIa inhibitors for acute coronary syndromes: Initiate treatment early or wait for the catheterization laboratory? (mssm.edu)
  • Vorchheimer, David A. / Platelet glycoprotein IIb/IIIa inhibitors for acute coronary syndromes : Initiate treatment early or wait for the catheterization laboratory? . (mssm.edu)
  • Objectives This study sought to evaluate the efficacy and safety of cangrelor compared with clopidogrel in subgroups that did and did not receive glycoprotein IIb/IIIa inhibitors (GPIs). (elsevierpure.com)
  • on behalf of the, CHAMPION Investigators & CHAMPION Investigators 2017, ' Cangrelor With and Without Glycoprotein IIb/IIIa Inhibitors in Patients Undergoing Percutaneous Coronary Intervention ', Journal of the American College of Cardiology , vol. 69, no. 2, pp. 176-185. (elsevierpure.com)
  • Aspirin, glycoprotein (GP) IIb/IIIa inhibitors, and clopidogrel have an inhibitory effect on platelet activation and aggregation. (medscape.com)
  • Shear-Mediated Platelet Microparticles Demonstrate Phenotypic Heterogeneity as to Morphology, Receptor Distribution, and Hemostatic Function. (harvard.edu)
  • Sex-specific platelet activation through protease-activated receptor-1 in patients undergoing cardiac catheterization. (harvard.edu)
  • Glanzmann thrombasthenia (GT) is a rare platelet disorder in which the platelets have qualitative or quantitative deficiencies of the fibrinogen receptor αIIbβ3. (medscape.com)
  • Background: In patients with ST-elevation myocardial infarction (STEMI), direct intracoronary bolus administration of the glycoprotein (GP) IIb/IIIa receptor antagonist abciximab is associated with a reduction in infarct size, better myocardial salvage, less microvascular obstruction and improved myocardial blush grade as compared to intravenous bolus injection, presumably caused by higher local drug concentrations leading to a more pronounced inhibition of platelet aggregation. (uni-luebeck.de)
  • We investigated whether there are differences in the degree of GP IIb/IIIa receptor occupancy and platelet inhibition in blood drawn from the coronary sinus (CS) shortly after intracoronary versus intravenous abciximab bolus administration. (uni-luebeck.de)
  • At late sampling after 30 min no significant differences were found between groups for both platelet reactivity and GP IIb/IIIa receptor occupancy. (uni-luebeck.de)
  • Conclusions: Acutely, direct intracoronary bolus injection resulted in a more pronounced local inhibition of platelet function and a higher degree of GP IIb/IIIa receptor occupancy as compared to standard intravenous bolus injection. (uni-luebeck.de)
  • Medications that inhibit the platelet glycoprotein IIb/IIIa receptor have been shown to be especially efficacious in the treatment of ACS. (mssm.edu)
  • Panel members preferred a single intravenous aspirin bolus or, in jurisdictions in which intravenous aspirin is not available, a glycoprotein IIb/IIIa receptor inhibitor as intraprocedural antiplatelet regimen and a combination therapy of oral aspirin and a P2Y12 inhibitor in the postprocedural period. (elsevierpure.com)
  • Panel members preferred intravenous aspirin or, alternatively, a glycoprotein IIb/IIIa receptor inhibitor as an intraprocedural antiplatelet agent, followed by a dual oral regimen of aspirin and a P2Y12 inhibitor in the postprocedural period. (elsevierpure.com)
  • Blockade of the platelet glycoprotein IIb/IIIa receptor by abciximab (c7E3 Fab) during coronary intervention reduces the incidence of ischemic complications, but has been associated with a doubling of the risk for bleeding complications. (houstonmethodist.org)
  • Selectively inhibits ADP binding to platelet receptor and subsequent ADP-mediated activation of glycoprotein GPIIb/IIIa complex, inhibiting platelet aggregation. (medscape.com)
  • The drug is an irreversible inhibitor of the P2Y12 adenosine diphosphate receptor found on the membranes of platelet cells. (itopmeds.com)
  • This active metabolite selectively inhibits adenosine diphosphate (ADP) binding to its platelet P2Y12 receptor and subsequently the ADP-mediated activation of the glycoprotein GPIIb/IIIa complex, thereby inhibiting platelet aggregation. (itopmeds.com)
  • The active metabolite of clopidogrel prevents binding of adenosine diphosphate (ADP) to its platelet receptor, impairing the ADP-mediated activation of the glycoprotein GPIIb/IIIa complex. (itopmeds.com)
  • he drug specifically and irreversibly inhibits the P2Y12 subtype of ADP receptor, which is important in aggregation of platelets and cross-linking by the protein fibrin. (itopmeds.com)
  • No direct interference occurs with the GPIIb/IIIa receptor. (itopmeds.com)
  • As the glycoprotein GPIIb/IIIa complex is the major receptor for fibrinogen, its impaired activation prevents fibrinogen binding to platelets and inhibits platelet aggregation. (itopmeds.com)
  • Qin R , Zhu H , Wang F , Song M , Lin P , Xing Y , Zhang W , Zhong M , Wang Z , . Platelet activation in diabetic mice models: the role of vascular endothelial cell-derived protein disulfide isomerase-mediated GP IIb/IIIa receptor activation. (aging-us.com)
  • GP IIb/IIIa receptor activation plays an important role in thrombosis. (aging-us.com)
  • It is a receptor for fibrinogen and von Willebrand factor and aids in platelet activation. (hemostasis.com)
  • The gpIIb/IIIa receptor is a target of several drugs including abciximab, eptifibatide, tirofiban. (hemostasis.com)
  • Platelet aggregation is stimulated by thromboxane and α2 receptor -activation, but inhibited by other inflammatory products like PGI2 and PGD2 . (wikidoc.org)
  • Results The A-allele of the rs12041331 SNP in the platelet endothelial aggregation receptor-1 ((rs12041331) reproducibly influenced platelet aggregation in aspirin-treated patients with coronary artery disease. (crispr-reagents.com)
  • The platelet surface hosts a panel of receptors mediating platelet activation and ultimately they all converge towards glycoprotein (GP) IIb/IIIa fibrinogen receptor complex. (crispr-reagents.com)
  • Los pequeños péptidos sintéticos que contienen la secuencia peptídica N-terminal no enmascarada pueden activar también el receptor en ausencia de actividad proteolítica. (bvsalud.org)
  • ITGA2B is a receptor for fibronectin, fibrinogen, plasminogen, prothrombin, thrombospondin and vitronectin and functions in platelet activation (5). (peertechzpublications.com)
  • Platelet membrane glycoprotein IIb-IIIa forms a calcium-dependent heterodimer and constitutes the fibrinogen receptor on stimulated platelets. (rupress.org)
  • 2001) A novel viper venom metalloproteinase, alborhagin, is an agonist at the platelet collagen receptor GPVI. (yoproteins.eu)
  • Platelet membrane glycoprotein complex important for platelet adhesion and aggregation. (harvard.edu)
  • 8. Khaspekova SG, Vyzova TV, Lukin VV, Tikhomirov OIu, Berndt M, Kouns W, Mazurov AV. (1996) [Conformational changes of the platelet membrane glycoprotein IIb-IIIa complex stimulated by a monoclonal antibody to the N-terminal segment of glycoprotein IIIa]. (yoproteins.eu)
  • 9. Khaspekova SG, Vlasik TN, Byzova TV, Vinogradov DV, Berndt MC, Mazurov AV. (1993) Detection of an epitope specific for the dissociated form of glycoprotein IIIa of platelet membrane glycoprotein IIb-IIIa complex and its expression on the surface of adherent platelets. (yoproteins.eu)
  • By blocking the amplification of platelet activation by released ADP, platelet aggregation induced by agonists other than ADP is also inhibited by the active metabolite of clopidogrel. (itopmeds.com)
  • Covalent binding to platelets has accounted for 2% of radiolabeled clopidogrel with a half-life of 11 days. (itopmeds.com)
  • Ticlopidine is a platelet aggregation inhibitor structurally and pharmacologically similar to clopidogrel. (lgmpharma.com)
  • Platelet activation by ADP (blocked by clopidogrel) leads to a conformational change in platelet gpIIb/IIIa receptors that induces binding to fibrinogen. (hemostasis.com)
  • 1. Khaspekova SG, Ziuriaev IT, Iakushkin VV, Golubeva NV, Ruda MIa, Mazurov AV. (2011) [Platelet aggregation upon acetylsalicylic acid and clopidogrel treatment and glycoprotein IIb/IIIa content in patients with acute coronary syndrome]. (yoproteins.eu)
  • The mechanism of early activation of GP IIb/IIIa receptors in diabetic conditions remains unknown. (aging-us.com)
  • In conclusion, EMP-PDI promotes early platelet activation through glycoprotein (GP) IIb/IIIa receptors present on platelet surface in the diabetic state. (aging-us.com)
  • However, the ultimate common pathway of platelet aggregation is the activation of glycoprotein (GP) IIb/IIIa receptors present on platelet surface [ 7 - 9 ]. (aging-us.com)
  • Under physiological conditions, the GP IIb/IIIa receptors are present in a low-affinity state and cannot bind to fibrinogen. (aging-us.com)
  • This process relies on the destruction of disulfide bonds present on these receptors, such as Cys5-Cys435, Cys663-Cys687, and a third Cys-rich repetitive zone, to be transformed into the ligand-binding, high-affinity state and evoke conformational changes in GP IIb/IIIa receptors [ 10 ]. (aging-us.com)
  • BACKGROUND: Studies have been performed on human fresh, liquid-preserved, and cryopreserved platelets (PLTs) to assess PLT-adhesive surface receptors, PLT membrane procoagulant activity, PLT aggregation, and thromboxane production. (umassmed.edu)
  • Platelets are activated when brought into contact with collagen (which is exposed when the endothelial blood vessel lining is damaged), thrombin (primarily through PAR -1), ADP receptors (P2Y1 and P2Y12) expressed on platelets, a negatively charged surface (e.g. glass), or several other activating factors. (wikidoc.org)
  • The platelets adhere to each other via adhesion receptors or integrins , and to the endothelial cells in the wall of the blood vessel forming a haemostatic plug in conjunction with fibrin . (wikidoc.org)
  • Other receptors include GPIb-V-IX complex (vWF) and GPVI ( collagen ). (wikidoc.org)
  • However given the considerable interdependency of platelet activation pathways and the fact that aspirin has effects impartial of COX-1 [8]-[9] the effect of aspirin may also be susceptible to genetically decided changes of various other receptors. (crispr-reagents.com)
  • The A to Z trial is the first large, randomized trial to examine the safety and efficacy of the combination of enoxaparin versus UFH with use of a GP IIb/IIIa inhibitor. (acc.org)
  • Evaluation of Platelet IIb/IIIa Inhibitor for Stenting. (duke.edu)
  • Dipyridamole is a platelet adhesion inhibitor that possibly inhibits RBC uptake of adenosine, itself an inhibitor of platelet reactivity. (medscape.com)
  • It has been proposed that 1 or more active metabolites may account for ticlopidine's activity, because ticlopidine itself is an extremely weak platelet aggregation inhibitor in vitro at the concentrations achieved in vivo. (lgmpharma.com)
  • Platelet Activation and Reactivity in a Large Cohort of Patients with Gaucher Disease. (harvard.edu)
  • Flow cytometry can be used to measure platelet reactivity, circulating activated platelets, platelet-platelet aggregates, leukocyte-platelet aggregates, procoagulant platelet-derived microparticles, and calcium flux. (umassmed.edu)
  • Furthermore heritable factors take into account around 30% from the variant in innate platelet reactivity [5] and Hydroxocobalamin (Vitamin B12a) hereditary variability can be an essential contributor to residual platelet reactivity during aspirin treatment [6]. (crispr-reagents.com)
  • Dematin Regulates Calcium Mobilization, Thrombosis, and Early Akt Activation in Platelets. (harvard.edu)
  • Exploratory Use of Glycoprotein IIb/IIIa Inhibition in Prevention of Blalock-Taussig Shunt Thrombosis. (harvard.edu)
  • The main effectors of coronary thrombosis are platelets, and hence, alterations of platelets and their functional characteristics may represent a conceptual bridge between these events. (johnshopkins.edu)
  • May be used in low dose to inhibit platelet aggregation and improve complications of venous stasis and thrombosis. (medscape.com)
  • In thrombosis, platelet activation serves as the initiation factor. (aging-us.com)
  • Dysfunction or low levels of platelets predisposes to bleeding , while high levels, although usually asymptomatic, may increase the risk of thrombosis . (wikidoc.org)
  • Both hemostasis and thrombosis depend on the coagulation cascade, vascular wall integrity, and platelet response. (medscape.com)
  • Here the current status of our knowledge is reviewed with specific emphasis upon the role of the platelet in the pathogenesis of thrombosis as well as the impact of recent data from ECLAP and MRC PT1. (ashpublications.org)
  • Thrombosis predominates in ET and PV and these entities are the subject of this article focussing upon the nature of thrombotic events and their pathogenesis, with an emphasis upon platelets. (ashpublications.org)
  • Integrin alpha 2b (ITGA2b), also known as CD41 and GPIIb, is a transmembrane glycoprotein that is expressed by megakaryocytes and platelets. (rndsystems.com)
  • CD41/CD61 is expressed on platelets and megakaryocytes, and plays a role in platelet activation and aggregation through interaction with fibrinogen, fibronectin, vWF, and other RGD-containing adhesion molecules. (biolegend.com)
  • Platelets are produced in hematopoiesis by budding off from megakaryocytes . (wikidoc.org)
  • Biosynthesis and processing of platelet GPIIb-IIIa in human megakaryocytes. (rupress.org)
  • To examine the biosynthesis and processing of GPIIb-IIIa, purified human megakaryocytes were isolated from liquid cultures of cryopreserved leukocytes stem cell concentrates from patients with chronic myelogenous leukemia. (rupress.org)
  • The glycosylation of GPIIb-IIIa was examined in megakaryocytes by metabolic labeling in the presence of tunicamycin, monensin, or treatment with endoglycosidase H. The polypeptide backbones of the GPIIb and the GPIIIa have molecular masses of 120 and 90 kD, respectively. (rupress.org)
  • The antibody reacts with human platelets and megakaryocytes. (yoproteins.eu)
  • The platelet integrin αIIbβ3, also known as the glycoprotein GPIIb/IIIa (CD41/CD61) complex, is essential for normal platelet function. (medscape.com)
  • Most patients have a normal platelet size and count. (medscape.com)
  • The complex is formed via calcium-dependent association of gpIIb and gpIIIa, a required step in normal platelet aggregation and endothelial adherence. (hemostasis.com)
  • A normal platelet count in a healthy person is between 150,000 and 400,000 per mm³ of blood (150-400 x 10 9 / L ). 95% of healthy people will have platelet counts in this range. (wikidoc.org)
  • Glycoprotein IIb/IIIa (GPIIb/IIIa, also known as integrin αIIbβ3) is an integrin complex found on platelets. (hemostasis.com)
  • CD61, also known as integrin ß3 and glycoprotein IIIa (gpIIIa), is a 90 kD type I integral transmembrane glycoprotein. (biolegend.com)
  • Aspirin inhibits prostaglandin synthesis, preventing formation of platelet-aggregating thromboxane A2. (medscape.com)
  • Aspirin inhibits the formation of thromboxane A2 in the platelets. (neisslabs.com)
  • Background Platelet aggregation during aspirin treatment displays considerable inter-individual variability. (crispr-reagents.com)
  • aggregation was evaluated by whole blood platelet aggregometry employing Multiplate Analyzer (agonists: arachidonic acid and collagen) and VerifyNow Aspirin. (crispr-reagents.com)
  • Furthermore 14 SNPs previously suggested to influence aspirin efficacy were not associated with on-aspirin platelet aggregation. (crispr-reagents.com)
  • This may reflect that some patients do not derive adequate platelet inhibition from Hydroxocobalamin (Vitamin B12a) aspirin [1]-[2]. (crispr-reagents.com)
  • In the search for genetic mechanisms to explain inadequate platelet inhibition by aspirin especially the IIIa subunit of the complex continues to be scrutinized [10]. (crispr-reagents.com)
  • Detection of Integrin alpha 2b/CD41 in Human Blood Platelets by Flow Cytometry. (rndsystems.com)
  • Human peripheral blood platelets were stained with FITC-conjugated Anti-Human Integrin a2b/CD41 Antibody (Clone P2) and either (A) Mouse Anti-Human Integrin a2b/CD41 APC-conjugated Monoclonal Antibody (Catalog # FAB7616A) or (B) Mouse IgG 1 Allophycocyanin Isotype Control (Catalog # IC002A ). (rndsystems.com)
  • It is a member of the integrin family, associating with platelet gpIIb (CD41) to form CD41/CD61 complex and with integrin aV (CD51) to form aV/ß3 (CD51/CD61) integrin. (biolegend.com)
  • The purpose of this study was to investigate the release of Endothelial microparticle (EMP)-associated protein disulfide isomerase (PDI) after endothelial cell injury induced in diabetes and the changes in platelet activation. (aging-us.com)
  • The exact biological mechanism remains elusive but the effect of this polymorphism may be related to changes in platelet activation. (crispr-reagents.com)
  • May have positive influence on several hemorrhagic parameters and may exert protection against atherosclerosis (inhibition of platelet function and changes in hemorrhagic profile). (medscape.com)
  • Reduction and weight adjustment of heparin dose and early sheath removal in the setting of platelet inhibition with abciximab during coronary intervention may be useful in diminishing the incidence of hemorrhagic complications without loss of clinical efficacy. (houstonmethodist.org)
  • Recombinant coagulation factor VIIa is approved for bleeding episodes and perioperative management in patients with GT refractory to platelet transfusions, with or without antibodies to platelets. (medscape.com)
  • Integrin alpha 2b is required for platelet aggregation, and defects lead to disorders of coagulation. (rndsystems.com)
  • This inhibits platelet aggregation and coagulation. (neisslabs.com)
  • Once activated, they release a number of different coagulation factors and platelet activating factors. (wikidoc.org)
  • Flow cytometry can also be used in the following clinical settings: monitoring of GPIIb-IIIa antagonist therapy, diagnosis of inherited deficiencies of platelet surface glycoproteins, diagnosis of storage pool disease, diagnosis of heparin-induced thrombocytopenia, and measurement of the rate of thrombopoiesis. (umassmed.edu)
  • Scholars@Duke publication: Outcomes at 1 year and economic implications of platelet glycoprotein IIb/IIIa blockade in patients undergoing coronary stenting: results from a multicentre randomised trial. (duke.edu)
  • Moreover, even marginal clinical benefits, together with recently reported severe bleeding events in some patients receiving oral platelet glycoprotein IIb/IIIa therapy, may potentially advance sertraline as a safe and efficient adjunct to the current therapeutic approach to the acute coronary syndrome. (johnshopkins.edu)
  • Clinical applications of whole blood flow cytometric assays of platelet function in disease states (e.g., acute coronary syndromes, angioplasty, and stroke) may include identification of patients who would benefit from additional antiplatelet therapy and prediction of ischemic events. (umassmed.edu)
  • Is transport with platelet GP IIb/IIIa inhibition for primary percutaneous coronary intervention more efficient than on-site thrombolysis in patients with STEMI admitted to community hospitals? (edu.pl)
  • 2010) [Glycoprotein IIb-IIIa antagonist Monafram in primary angioplasty of patients with acute coronary syndrome without st segment elevation]. (yoproteins.eu)
  • Koray Ak, Ergun S, Altınoz H, Uyguner ZO, Tetik S (2016) GG Polymorphism of Platelet ITGA2B Gene Increases the Magnitude of Interleukin-6 Release after Cardiopulmonary Bypass. (peertechzpublications.com)
  • In this study we aimed to investigate the effect of ITGA2B (integrin alpha 2b, platelet glycoprotein IIb of IIb/IIIa complex) gene polymorphism on the magnitude of inflammatory response after CPB. (peertechzpublications.com)
  • 3. Sirotkina OV, Khaspekova SG, Zabotina AM, Shimanova YV, Mazurov AV. (2007) Effects of platelet glycoprotein IIb-IIIa number and glycoprotein IIIa Leu33Pro polymorphism on platelet aggregation and sensitivity to glycoprotein IIb-IIIa antagonists. (yoproteins.eu)
  • However, diabetic patients have significantly higher platelet aggregation and activation than non-diabetic patients, including those undergoing dual antiplatelet therapy [ 4 - 6 ]. (aging-us.com)
  • Application of flow cytometry to platelet disorders. (umassmed.edu)
  • Platelet function in whole blood can be comprehensively evaluated by flow cytometry. (umassmed.edu)
  • Inhibits prostaglandin synthesis, which prevents formation of platelet-aggregating thromboxane A2. (medscape.com)
  • May also inhibit phosphodiesterase activity, leading to increased cyclic-3', 5'-adenosine monophosphate levels in platelets and formation of the potent platelet activator thromboxane A2. (medscape.com)
  • STUDY DESIGN AND METHODS: In both human and baboon fresh and lyophilized PLTs, aggregation response and PLT production of thromboxane A2 were measured after stimulation, and PLT surface markers P-selectin, glycoprotein (GP) Ib, GPIIb-IIIa, and factor (F) V were measured before and after stimulation. (umassmed.edu)
  • RESULTS: Fresh PLTs responded to the dual agonists arachidonic acid and adenosine diphosphate (ADP) to aggregate and produce thromboxane A2, and in both the PLT surface markers P-selectin and GPIIb-IIIa increased and GPIb decreased after stimulation. (umassmed.edu)
  • There was no consensus on the role of platelet function testing in the postprocedural period. (elsevierpure.com)
  • [ 4 ] With platelet activation, the αIIbβ3 complex shifts into its active configuration, which allows the binding of fibrinogen and/or von Willebrand factor (vWF). (medscape.com)
  • Integrin alpha 2b associates with Integrin beta 3 to form complexes that interact with Fibrinogen, von Willebrand factor, Fibronectin, and Vitronectin. (rndsystems.com)
  • 4. Naimushin YA, Mazurov AV. (2004) Von Willebrand factor can support platelet aggregation via interaction with activated GPIIb-IIIa and GPIb. (yoproteins.eu)
  • M, Gresele P. Expert opinion on the use of platelet secretion assay for the diagnosis of inherited platelet function disorders: Communication from the ISTH SSC Subcommittee on Platelet Physiology. (umassmed.edu)
  • Mumford AD, Frelinger AL, Gachet C, Gresele P, Noris P, Harrison P, Mezzano D. A review of platelet secretion assays for the diagnosis of inherited platelet secretion disorders. (umassmed.edu)
  • The antibody is specific to the integrin complex alpha 2b beta 3, but not to the dissociated integrins. (yoproteins.eu)
  • It is an integrin complex containing INTEGRIN ALPHAIIB and INTEGRIN BETA3 which recognizes the arginine-glycine-aspartic acid (RGD) sequence present on several adhesive proteins. (harvard.edu)
  • The antibody does not react with platelets from patients with the hereditary deficiency of GP IIb-IIIa (Glanzmann's thrombasthenia). (yoproteins.eu)
  • Glanzmann's thrombasthenia (GT) is a rare, genetically inherited, functional disorder of platelets. (aeirc-edu.com)
  • The collagen-induced platelet aggregation of platelet-rich plasma samples from 14 healthy rabbits was measured turbidometrically using a platelet aggregometer, before and 1 hour after intravenous injection of alum. (who.int)
  • Collagen-induced platelet aggregation was significantly reduced after alum injection. (who.int)
  • contradiction in the mechanism of action of alum, we evaluated the in vivo effect of Alum (aluminium potassium sulfate) is a alum in terms of collagen-induced platelet food additive and traditional remedy used to aggregation and bleeding time. (who.int)
  • These drugs provide not only a safe blockade of serotonin reuptake in the brain, but also in platelets, thus potentially protecting them from activation. (johnshopkins.edu)
  • They are found primarily on PLATELETS and on ENDOTHELIAL CELLS. (bvsalud.org)
  • Methods This pooled, patient-level analysis of the 3 CHAMPION (Cangrelor versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition) trials analyzed all randomized patients who underwent PCI and received the study drug (n = 24,902). (elsevierpure.com)
  • Stimulation of platelet functional reactions and binding with membrane glycoproteins. (yoproteins.eu)
  • A defect in either glycoprotein can lead to a bleeding disorder. (medscape.com)
  • Platelets , or thrombocytes , are the cells circulating in the blood that are involved in the cellular mechanisms of primary hemostasis leading to the formation of blood clots . (wikidoc.org)
  • Platelets are small cells that circulate in blood and are an essential component of blood clots. (medlineplus.gov)
  • Platelets stored in plasma or in GAC were equally functional when tested for aggregation and adenosine triphosphate (ATP) secretion. (amsterdamumc.org)
  • Activation of platelets was measured by binding of monoclonal antibodies (McAb) against the Gp IIb/IIIa complex and against activation‐dependent antigens (GMP 140 from the α‐granules and a 53‐kD glycoprotein from the lysosomal granules). (amsterdamumc.org)
  • 2001) [Inhibition of thrombocyte aggregation by F(ab')2-fragments of monoclonal antibodies FraMon (CRC64) to glycoproteins IIb-IIIa]. (yoproteins.eu)
  • Patients with GT who are bleeding require platelet transfusion. (medscape.com)
  • Patients with Glanzmann thrombasthenia can have severe bleeding problems, but their prognosis remains good with appropriate supportive care and platelet transfusions if necessary. (medscape.com)
  • Nevertheless, the platelet-related properties of SSRI may strongly affect the incidence of complications in patients with ischemic heart disease. (johnshopkins.edu)
  • Angioembolization with added infusion of factor VII, can be considered an equally effective alternate to platelet transfusion in patients of GT, who present with recurrent bleeding. (aeirc-edu.com)
  • Ces résultats semblent indiquer que l'utilisation de l'alun en tant qu'antiplaquettaire oral pourrait faire l'objet d'études complémentaires, en tenant compte des effets secondaires éventuels notamment chez les patients dont la fonction rénale est altérée. (who.int)
  • [ 5 ] Acquired Glanzmann thrombasthenia is characterized by anti-αIIbβ3 autoantibodies or paraproteins that block platelet aggregation. (medscape.com)
  • Adjacent platelets are cross-linked through the αIIβ3, resulting in platelet aggregation and hemostasis. (medscape.com)
  • Retraction of a clot resulting from contraction of PLATELET pseudopods attached to FIBRIN strands. (lookformedical.com)
  • It is proposed that the inhibition involves a defect in the mobilization from the storage sites of the platelet granules to the outer membrane. (itopmeds.com)
  • The contents of the granules are released upon activation of the platelet. (wikidoc.org)
  • Immunoprecipitation of [35S]methionine pulse-chase-labeled cell extracts by antibodies specific for the alpha or beta subunits of GPIIb indicated that GPIIb was derived from a precursor of Mr 130,000 that contains the alpha and beta subunits. (rupress.org)
  • We conclude that platelets prepared by the buffy‐coat method and stored in GAC have the same in vitro qualitities as platelets stored in plasma, except for the lower aggregation response by the archidonic‐acid pathway. (amsterdamumc.org)