The process of the interaction of BLOOD COAGULATION FACTORS that results in an insoluble FIBRIN clot.
Endogenous substances, usually proteins, that are involved in the blood coagulation process.
A fibrin-stabilizing plasma enzyme (TRANSGLUTAMINASES) that is activated by THROMBIN and CALCIUM to form FACTOR XIIIA. It is important for stabilizing the formation of the fibrin polymer (clot) which culminates the coagulation cascade.
Storage-stable blood coagulation factor acting in the intrinsic pathway. Its activated form, IXa, forms a complex with factor VIII and calcium on platelet factor 3 to activate factor X to Xa. Deficiency of factor IX results in HEMOPHILIA B (Christmas Disease).
Storage-stable glycoprotein blood coagulation factor that can be activated to factor Xa by both the intrinsic and extrinsic pathways. A deficiency of factor X, sometimes called Stuart-Prower factor deficiency, may lead to a systemic coagulation disorder.
Activated form of factor X that participates in both the intrinsic and extrinsic pathways of blood coagulation. It catalyzes the conversion of prothrombin to thrombin in conjunction with other cofactors.
Heat- and storage-stable plasma protein that is activated by tissue thromboplastin to form factor VIIa in the extrinsic pathway of blood coagulation. The activated form then catalyzes the activation of factor X to factor Xa.
Blood-coagulation factor VIII. Antihemophilic factor that is part of the factor VIII/von Willebrand factor complex. Factor VIII is produced in the liver and acts in the intrinsic pathway of blood coagulation. It serves as a cofactor in factor X activation and this action is markedly enhanced by small amounts of thrombin.
Activated form of factor XI. In the intrinsic pathway, Factor XI is activated to XIa by factor XIIa in the presence of cofactor HMWK; (HIGH MOLECULAR WEIGHT KININOGEN). Factor XIa then activates factor IX to factor IXa in the presence of calcium.
Laboratory tests for evaluating the individual's clotting mechanism.
Constituent composed of protein and phospholipid that is widely distributed in many tissues. It serves as a cofactor with factor VIIa to activate factor X in the extrinsic pathway of blood coagulation.
Activated form of factor VII. Factor VIIa activates factor X in the extrinsic pathway of blood coagulation.
Hemorrhagic and thrombotic disorders that occur as a consequence of abnormalities in blood coagulation due to a variety of factors such as COAGULATION PROTEIN DISORDERS; BLOOD PLATELET DISORDERS; BLOOD PROTEIN DISORDERS or nutritional conditions.
Stable blood coagulation factor involved in the intrinsic pathway. The activated form XIa activates factor IX to IXa. Deficiency of factor XI is often called hemophilia C.
Activated form of factor IX. This activation can take place via the intrinsic pathway by the action of factor XIa and calcium, or via the extrinsic pathway by the action of factor VIIa, thromboplastin, and calcium. Factor IXa serves to activate factor X to Xa by cleaving the arginyl-leucine peptide bond in factor X.
Agents that cause clotting.
Heat- and storage-labile plasma glycoprotein which accelerates the conversion of prothrombin to thrombin in blood coagulation. Factor V accomplishes this by forming a complex with factor Xa, phospholipid, and calcium (prothrombinase complex). Deficiency of factor V leads to Owren's disease.
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.
A disorder characterized by procoagulant substances entering the general circulation causing a systemic thrombotic process. The activation of the clotting mechanism may arise from any of a number of disorders. A majority of the patients manifest skin lesions, sometimes leading to PURPURA FULMINANS.
The time required for the appearance of FIBRIN strands following the mixing of PLASMA with phospholipid platelet substitute (e.g., crude cephalins, soybean phosphatides). It is a test of the intrinsic pathway (factors VIII, IX, XI, and XII) and the common pathway (fibrinogen, prothrombin, factors V and X) of BLOOD COAGULATION. It is used as a screening test and to monitor HEPARIN therapy.
Clotting time of PLASMA recalcified in the presence of excess TISSUE THROMBOPLASTIN. Factors measured are FIBRINOGEN; PROTHROMBIN; FACTOR V; FACTOR VII; and FACTOR X. It is used for monitoring anticoagulant therapy with COUMARINS.
An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.
Stable blood coagulation factor activated by contact with the subendothelial surface of an injured vessel. Along with prekallikrein, it serves as the contact factor that initiates the intrinsic pathway of blood coagulation. Kallikrein activates factor XII to XIIa. Deficiency of factor XII, also called the Hageman trait, leads to increased incidence of thromboembolic disease. Mutations in the gene for factor XII that appear to increase factor XII amidolytic activity are associated with HEREDITARY ANGIOEDEMA TYPE III.
Activated form of factor V. It is an essential cofactor for the activation of prothrombin catalyzed by factor Xa.
Substances, usually endogenous, that act as inhibitors of blood coagulation. They may affect one or multiple enzymes throughout the process. As a group, they also inhibit enzymes involved in processes other than blood coagulation, such as those from the complement system, fibrinolytic enzyme system, blood cells, and bacteria.
A vitamin-K dependent zymogen present in the blood, which, upon activation by thrombin and thrombomodulin exerts anticoagulant properties by inactivating factors Va and VIIIa at the rate-limiting steps of thrombin formation.
Activated form of factor VIII. The B-domain of factor VIII is proteolytically cleaved by thrombin to form factor VIIIa. Factor VIIIa exists as a non-covalent dimer in a metal-linked (probably calcium) complex and functions as a cofactor in the enzymatic activation of factor X by factor IXa. Factor VIIIa is similar in structure and generation to factor Va.
Found in various tissues, particularly in four blood-clotting proteins including prothrombin, in kidney protein, in bone protein, and in the protein present in various ectopic calcifications.
A deficiency of blood coagulation factor IX inherited as an X-linked disorder. (Also known as Christmas Disease, after the first patient studied in detail, not the holy day.) Historical and clinical features resemble those in classic hemophilia (HEMOPHILIA A), but patients present with fewer symptoms. Severity of bleeding is usually similar in members of a single family. Many patients are asymptomatic until the hemostatic system is stressed by surgery or trauma. Treatment is similar to that for hemophilia A. (From Cecil Textbook of Medicine, 19th ed, p1008)
A lipid cofactor that is required for normal blood clotting. Several forms of vitamin K have been identified: VITAMIN K 1 (phytomenadione) derived from plants, VITAMIN K 2 (menaquinone) from bacteria, and synthetic naphthoquinone provitamins, VITAMIN K 3 (menadione). Vitamin K 3 provitamins, after being alkylated in vivo, exhibit the antifibrinolytic activity of vitamin K. Green leafy vegetables, liver, cheese, butter, and egg yolk are good sources of vitamin K.
Transglutaminases catalyze cross-linking of proteins at a GLUTAMINE in one chain with LYSINE in another chain. They include keratinocyte transglutaminase (TGM1 or TGK), tissue transglutaminase (TGM2 or TGC), plasma transglutaminase involved with coagulation (FACTOR XIII and FACTOR XIIIa), hair follicle transglutaminase, and prostate transglutaminase. Although structures differ, they share an active site (YGQCW) and strict CALCIUM dependence.
The classic hemophilia resulting from a deficiency of factor VIII. It is an inherited disorder of blood coagulation characterized by a permanent tendency to hemorrhage.
A plasma alpha 2 glycoprotein that accounts for the major antithrombin activity of normal plasma and also inhibits several other enzymes. It is a member of the serpin superfamily.
A family of ark shell mollusks, in the class BIVALVIA. They have soft bodies with platelike GILLS enclosed within two shells hinged together.
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.
Use of a thrombelastograph, which provides a continuous graphic record of the physical shape of a clot during fibrin formation and subsequent lysis.
Endogenous factors and drugs that directly inhibit the action of THROMBIN, usually by blocking its enzymatic activity. They are distinguished from INDIRECT THROMBIN INHIBITORS, such as HEPARIN, which act by enhancing the inhibitory effects of antithrombins.
A protein derived from FIBRINOGEN in the presence of THROMBIN, which forms part of the blood clot.
Agents that prevent clotting.
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.
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.
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.
A nutritional condition produced by a deficiency of VITAMIN K in the diet, characterized by an increased tendency to hemorrhage (HEMORRHAGIC DISORDERS). Such bleeding episodes may be particularly severe in newborn infants. (From Cecil Textbook of Medicine, 19th ed, p1182)
Amidines substituted with a benzene group. Benzamidine and its derivatives are known as peptidase inhibitors.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
An absence or reduced level of blood coagulation factor XII. It normally occurs in the absence of patient or family history of hemorrhagic disorders and is marked by prolonged clotting time.
The natural enzymatic dissolution of FIBRIN.
Activated form of factor XII. In the initial event in the intrinsic pathway of blood coagulation, kallikrein (with cofactor HIGH MOLECULAR WEIGHT KININOGEN) cleaves factor XII to XIIa. Factor XIIa is then further cleaved by kallikrein, plasmin, and trypsin to yield smaller factor XII fragments (Hageman-Factor fragments). These fragments increase the activity of prekallikrein to kallikrein but decrease the procoagulant activity of factor XII.
The time required by whole blood to produce a visible clot.
The rate dynamics in chemical or physical systems.
Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.
Hemorrhagic and thrombotic disorders that occur as a consequence of inherited abnormalities in blood coagulation.
Exogenous or endogenous compounds which inhibit SERINE ENDOPEPTIDASES.
A hereditary deficiency of blood coagulation factor XI (also known as plasma thromboplastin antecedent or PTA or antihemophilic factor C) resulting in a systemic blood-clotting defect called hemophilia C or Rosenthal's syndrome, that may resemble classical hemophilia.
Proteins prepared by recombinant DNA technology.
A deficiency of blood coagulation FACTOR XIII or fibrin stabilizing factor (FSF) that prevents blood clot formation and results in a clinical hemorrhagic diathesis.
Hemorrhagic and thrombotic disorders resulting from abnormalities or deficiencies of coagulation proteins.
Clotting time of PLASMA mixed with a THROMBIN solution. It is a measure of the conversion of FIBRINOGEN to FIBRIN, which is prolonged by AFIBRINOGENEMIA, abnormal fibrinogen, or the presence of inhibitory substances, e.g., fibrin-fibrinogen degradation products, or HEPARIN. BATROXOBIN, a thrombin-like enzyme unaffected by the presence of heparin, may be used in place of thrombin.
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
The vitamin K-dependent cofactor of activated PROTEIN C. Together with protein C, it inhibits the action of factors VIIIa and Va. A deficiency in protein S; (PROTEIN S DEFICIENCY); can lead to recurrent venous and arterial thrombosis.
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.
Physiologically inactive substances that can be converted to active enzymes.
Formation and development of a thrombus or blood clot in the blood vessel.
Starches that have been chemically modified so that a percentage of OH groups are substituted with 2-hydroxyethyl ether groups.
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 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).
Soluble protein fragments formed by the proteolytic action of plasmin on fibrin or fibrinogen. FDP and their complexes profoundly impair the hemostatic process and are a major cause of hemorrhage in intravascular coagulation and fibrinolysis.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Activated form of FACTOR XIII, a transglutaminase, which stabilizes the formation of the fibrin polymer (clot) culminating the blood coagulation cascade.
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.
Any liquid used to replace blood plasma, usually a saline solution, often with serum albumins, dextrans or other preparations. These substances do not enhance the oxygen- carrying capacity of blood, but merely replace the volume. They are also used to treat dehydration.
Blood coagulation disorder usually inherited as an autosomal recessive trait, though it can be acquired. It is characterized by defective activity in both the intrinsic and extrinsic pathways, impaired thromboplastin time, and impaired prothrombin consumption.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Absence or reduced levels of PROTHROMBIN in the blood.
The most common mineral of a group of hydrated aluminum silicates, approximately H2Al2Si2O8-H2O. It is prepared for pharmaceutical and medicinal purposes by levigating with water to remove sand, etc. (From Merck Index, 11th ed) The name is derived from Kao-ling (Chinese: "high ridge"), the original site. (From Grant & Hackh's Chemical Dictionary, 5th ed)
A deficiency of blood coagulation factor V (known as proaccelerin or accelerator globulin or labile factor) leading to a rare hemorrhagic tendency known as Owren's disease or parahemophilia. It varies greatly in severity. Factor V deficiency is an autosomal recessive trait. (Dorland, 27th ed)
The sum of the weight of all the atoms in a molecule.
An autosomal recessive characteristic or a coagulation disorder acquired in association with VITAMIN K DEFICIENCY. FACTOR VII is a Vitamin K dependent glycoprotein essential to the extrinsic pathway of coagulation.
A plasma protein which is the precursor of kallikrein. Plasma that is deficient in prekallikrein has been found to be abnormal in thromboplastin formation, kinin generation, evolution of a permeability globulin, and plasmin formation. The absence of prekallikrein in plasma leads to Fletcher factor deficiency, a congenital disease.
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.
A cell surface glycoprotein of endothelial cells that binds thrombin and serves as a cofactor in the activation of protein C and its regulation of blood coagulation.
Spontaneous or near spontaneous bleeding caused by a defect in clotting mechanisms (BLOOD COAGULATION DISORDERS) or another abnormality causing a structural flaw in the blood vessels (HEMOSTATIC DISORDERS).
Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Two small peptide chains removed from the N-terminal segment of the alpha chains of fibrinogen by the action of thrombin during the blood coagulation process. Each peptide chain contains 18 amino acid residues. In vivo, fibrinopeptide A is used as a marker to determine the rate of conversion of fibrinogen to fibrin by thrombin.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Agents acting to arrest the flow of blood. Absorbable hemostatics arrest bleeding either by the formation of an artificial clot or by providing a mechanical matrix that facilitates clotting when applied directly to the bleeding surface. These agents function more at the capillary level and are not effective at stemming arterial or venous bleeding under any significant intravascular pressure.
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
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.
The residual portion of BLOOD that is left after removal of BLOOD CELLS by CENTRIFUGATION without prior BLOOD COAGULATION.
Bleeding or escape of blood from a vessel.
Enzymes that catalyze the joining of two molecules by the formation of a carbon-carbon bond. These are the carboxylating enzymes and are mostly biotinyl-proteins. EC 6.4.
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.
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.
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.
Proteins obtained from species of REPTILES.
A member of the serpin superfamily found in plasma that inhibits the lysis of fibrin clots which are induced by plasminogen activator. It is a glycoprotein, molecular weight approximately 70,000 that migrates in the alpha 2 region in immunoelectrophoresis. It is the principal plasmin inactivator in blood, rapidly forming a very stable complex with plasmin.
A method of tissue ablation and bleeding control that uses ARGON plasma (ionized argon gas) to deliver a current of thermocoagulating energy to the area of tissue to be coagulated.
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.
DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.
A disorder of HEMOSTASIS in which there is a tendency for the occurrence of THROMBOSIS.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
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.
A 6-kDa polypeptide growth factor initially discovered in mouse submaxillary glands. Human epidermal growth factor was originally isolated from urine based on its ability to inhibit gastric secretion and called urogastrone. Epidermal growth factor exerts a wide variety of biological effects including the promotion of proliferation and differentiation of mesenchymal and EPITHELIAL CELLS. It is synthesized as a transmembrane protein which can be cleaved to release a soluble active form.
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.
Proteolytic enzymes from the serine endopeptidase family found in normal blood and urine. Specifically, Kallikreins are potent vasodilators and hypotensives and increase vascular permeability and affect smooth muscle. They act as infertility agents in men. Three forms are recognized, PLASMA KALLIKREIN (EC 3.4.21.34), TISSUE KALLIKREIN (EC 3.4.21.35), and PROSTATE-SPECIFIC ANTIGEN (EC 3.4.21.77).
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.
Endogenous peptides present in most body fluids. Certain enzymes convert them to active KININS which are involved in inflammation, blood clotting, complement reactions, etc. Kininogens belong to the cystatin superfamily. They are cysteine proteinase inhibitors. HIGH-MOLECULAR-WEIGHT KININOGEN; (HMWK); is split by plasma kallikrein to produce BRADYKININ. LOW-MOLECULAR-WEIGHT KININOGEN; (LMWK); is split by tissue kallikrein to produce KALLIDIN.
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.
Lipid-protein complexes involved in the transportation and metabolism of lipids in the body. They are spherical particles consisting of a hydrophobic core of TRIGLYCERIDES and CHOLESTEROL ESTERS surrounded by a layer of hydrophilic free CHOLESTEROL; PHOSPHOLIPIDS; and APOLIPOPROTEINS. Lipoproteins are classified by their varying buoyant density and sizes.
A thrombin receptor subtype that couples to HETEROTRIMERIC GTP-BINDING PROTEINS resulting in the activation of a variety of signaling mechanisms including decreased intracellular CYCLIC AMP, increased TYPE C PHOSPHOLIPASES and increased PHOSPHOLIPASE A2.
The number of PLATELETS per unit volume in a sample of venous BLOOD.
A deficiency or absence of FIBRINOGEN in the blood.
Duration of blood flow after skin puncture. This test is used as a measure of capillary and platelet function.
Established cell cultures that have the potential to propagate indefinitely.
Solutions or mixtures of toxic and nontoxic substances elaborated by snake (Ophidia) salivary glands for the purpose of killing prey or disabling predators and delivered by grooved or hollow fangs. They usually contain enzymes, toxins, and other factors.
A family of proteinase-activated receptors that are specific for THROMBIN. They are found primarily on PLATELETS and on ENDOTHELIAL CELLS. Activation of thrombin receptors occurs through the proteolytic action of THROMBIN, which cleaves the N-terminal peptide from the receptor to reveal a new N-terminal peptide that is a cryptic ligand for the receptor. The receptors signal through HETEROTRIMERIC GTP-BINDING PROTEINS. Small synthetic peptides that contain the unmasked N-terminal peptide sequence can also activate the receptor in the absence of proteolytic activity.
Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a serine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and serine and 2 moles of fatty acids.
An anticoagulant that acts by inhibiting the synthesis of vitamin K-dependent coagulation factors. Warfarin is indicated for the prophylaxis and/or treatment of venous thrombosis and its extension, pulmonary embolism, and atrial fibrillation with embolization. It is also used as an adjunct in the prophylaxis of systemic embolism after myocardial infarction. Warfarin is also used as a rodenticide.
Agents that prevent fibrinolysis or lysis of a blood clot or thrombus. Several endogenous antiplasmins are known. The drugs are used to control massive hemorrhage and in other coagulation disorders.
Inflammation of a vein associated with a blood clot (THROMBUS).
An arthropod subclass (Xiphosura) comprising the North American (Limulus) and Asiatic (Tachypleus) genera of horseshoe crabs.
Precursor of plasmin (FIBRINOLYSIN). It is a single-chain beta-globulin of molecular weight 80-90,000 found mostly in association with fibrinogen in plasma; plasminogen activators change it to fibrinolysin. It is used in wound debriding and has been investigated as a thrombolytic agent.
Reduction of blood viscosity usually by the addition of cell free solutions. Used clinically (1) in states of impaired microcirculation, (2) for replacement of intraoperative blood loss without homologous blood transfusion, and (3) in cardiopulmonary bypass and hypothermia.
Elements of limited time intervals, contributing to particular results or situations.
A family of snakes comprising three subfamilies: Azemiopinae (the mountain viper, the sole member of this subfamily), Viperinae (true vipers), and Crotalinae (pit vipers). They are widespread throughout the world, being found in the United States, Central and South America, Europe, Asia and Africa. Their venoms act on the blood (hemotoxic) as compared to the venom of elapids which act on the nervous system (neurotoxic). (Goin, Goin, and Zug, Introduction to Herpetology, 3d ed, pp333-36)
The use of green light-producing LASERS to stop bleeding. The green light is selectively absorbed by HEMOGLOBIN, thus triggering BLOOD COAGULATION.
A biosensing technique in which biomolecules capable of binding to specific analytes or ligands are first immobilized on one side of a metallic film. Light is then focused on the opposite side of the film to excite the surface plasmons, that is, the oscillations of free electrons propagating along the film's surface. The refractive index of light reflecting off this surface is measured. When the immobilized biomolecules are bound by their ligands, an alteration in surface plasmons on the opposite side of the film is created which is directly proportional to the change in bound, or adsorbed, mass. Binding is measured by changes in the refractive index. The technique is used to study biomolecular interactions, such as antigen-antibody binding.
A genus of snakes of the family VIPERIDAE. It is distributed in West Pakistan, most of India, Burma, Ceylon, Thailand, southeast China, Taiwan, and a few islands of Indonesia. It hisses loudly when disturbed and strikes with great force and speed. Very prolific, it gives birth to 20-60 young. This viper is the leading cause of snakebite in India and Burma. (Moore: Poisonous Snakes of the World, 1980, p127)
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.
Proteins synthesized by organisms belonging to the phylum ARTHROPODA. Included in this heading are proteins from the subdivisions ARACHNIDA; CRUSTACEA; and HORSESHOE CRABS. Note that a separate heading for INSECT PROTEINS is listed under this heading.
The formation or presence of a blood clot (THROMBUS) within a vein.
Hormones produced by invertebrates, usually insects, mollusks, annelids, and helminths.
Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.
Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.
A 3.5 per cent colloidal solution containing urea-cross-linked polymerized peptides. It has a molecular weight of approximately 35,000 and is prepared from gelatin and electrolytes. The polymeric solution is used as a plasma expander.
Procedures using an electrically heated wire or scalpel to treat hemorrhage (e.g., bleeding ulcers) and to ablate tumors, mucosal lesions, and refractory arrhythmias. It is different from ELECTROSURGERY which is used more for cutting tissue than destroying and in which the patient is part of the electric circuit.
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.
The process whereby PLATELETS adhere to something other than platelets, e.g., COLLAGEN; BASEMENT MEMBRANE; MICROFIBRILS; or other "foreign" surfaces.
Obstruction of a blood vessel (embolism) by a blood clot (THROMBUS) in the blood stream.
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.
Fibrinolysin or agents that convert plasminogen to FIBRINOLYSIN.
OXIDOREDUCTASES which mediate vitamin K metabolism by converting inactive vitamin K 2,3-epoxide to active vitamin K.
A peptidohydrolytic enzyme that is formed from PREKALLIKREIN by FACTOR XIIA. It activates FACTOR XII; FACTOR VII; and PLASMINOGEN. It is selective for both ARGININE and to a lesser extent LYSINE bonds. EC 3.4.21.34.
Limbless REPTILES of the suborder Serpentes.
A foul-smelling diamine formed by bacterial decarboxylation of lysine.
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.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
A di-isopropyl-fluorophosphate which is an irreversible cholinesterase inhibitor used to investigate the NERVOUS SYSTEM.
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.
A plant genus of the family MORACEAE. Puag-haad extract, from A. lakoocha, contains STILBENES and related 4-substituted RESORCINOLS.
A genus of snakes of the family VIPERIDAE. About 30 species are currently recognized, found in southeast Asia and adjacent island chains. The Okinawa habu frequently enters dwellings in search of rats and mice; the Chinese habu is often found in suburban and agricultural areas. They are quite irritable. (Moore: Poisonous Snakes of the World, 1980, p136)
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
Single pavement layer of cells which line the luminal surface of the entire vascular system and regulate the transport of macromolecules and blood components.
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.
GLYCOSPHINGOLIPIDS with a sulfate group esterified to one of the sugar groups.
A member of the serpin family of proteins. It inhibits both the tissue-type and urokinase-type plasminogen activators.
A hemostatic disorder characterized by a poor anticoagulant response to activated protein C (APC). The activated form of Factor V (Factor Va) is more slowly degraded by activated protein C. Factor V Leiden mutation (R506Q) is the most common cause of APC resistance.
Serum proteins that inhibit, antagonize, or inactivate COMPLEMENT C1 or its subunits.
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 salt used to replenish calcium levels, as an acid-producing diuretic, and as an antidote for magnesium poisoning.
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.
Hemorrhage caused by vitamin K deficiency.
An absence or deficiency in PROTEIN C which leads to impaired regulation of blood coagulation. It is associated with an increased risk of severe or premature thrombosis. (Stedman's Med. Dict., 26th ed.)
Loss of blood during a surgical procedure.
The introduction of whole blood or blood component directly into the blood stream. (Dorland, 27th ed)
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The relationship between the dose of an administered drug and the response of the organism to the drug.
A family of serine proteinase inhibitors which are similar in amino acid sequence and mechanism of inhibition, but differ in their specificity toward proteolytic enzymes. This family includes alpha 1-antitrypsin, angiotensinogen, ovalbumin, antiplasmin, alpha 1-antichymotrypsin, thyroxine-binding protein, complement 1 inactivators, antithrombin III, heparin cofactor II, plasminogen inactivators, gene Y protein, placental plasminogen activator inhibitor, and barley Z protein. Some members of the serpin family may be substrates rather than inhibitors of SERINE ENDOPEPTIDASES, and some serpins occur in plants where their function is not known.
Colorless, endogenous or exogenous pigment precursors that may be transformed by biological mechanisms into colored compounds; used in biochemical assays and in diagnosis as indicators, especially in the form of enzyme substrates. Synonym: chromogens (not to be confused with pigment-synthesizing bacteria also called chromogens).
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.
An order of nematodes of the subclass SECERNENTEA. Characteristics include an H-shaped excretory system with two subventral glands.
A fused four ring compound occurring free or combined in galls. Isolated from the kino of Eucalyptus maculata Hook and E. Hemipholia F. Muell. Activates Factor XII of the blood clotting system which also causes kinin release; used in research and as a dye.
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)
A pathological process characterized by injury or destruction of tissues caused by a variety of cytologic and chemical reactions. It is usually manifested by typical signs of pain, heat, redness, swelling, and loss of function.
Cephalosporin antibiotic, partly plasma-bound, that is effective against gram-negative and gram-positive organisms.
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.
Peptides composed of between two and twelve amino acids.
A family of soil bacteria. It also includes some parasitic forms.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.
Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Arginine derivative which is a substrate for many proteolytic enzymes. As a substrate for the esterase from the first component of complement, it inhibits the action of C(l) on C(4).
Antibodies produced by a single clone of cells.
A class of receptors that are activated by the action of PROTEINASES. The most notable examples are the THROMBIN RECEPTORS. The receptors contain cryptic ligands that are exposed upon the selective proteolysis of specific N-terminal cleavage sites.
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.
Venous vessels in the umbilical cord. They carry oxygenated, nutrient-rich blood from the mother to the FETUS via the PLACENTA. In humans, there is normally one umbilical vein.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Compounds which inhibit or antagonize biosynthesis or actions of proteases (ENDOPEPTIDASES).
An infant born at or after 42 weeks of gestation.
Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.
Poisonous animal secretions forming fluid mixtures of many different enzymes, toxins, and other substances. These substances are produced in specialized glands and secreted through specialized delivery systems (nematocysts, spines, fangs, etc.) for disabling prey or predator.
Substances that display the physical properties of ELASTICITY and VISCOSITY. The dual-nature of these substances causes them to resist applied forces in a time-dependent manner.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
A malignant tumor originating from the endothelial cells of lymphatic vessels. Most lymphangiosarcomas arise in an arm secondary to radical mastectomy but they sometimes complicate idiopathic lymphedema. The lymphedema has usually been present for 6 to 10 years before malignant changes develop. (From Dorland, 27th ed; Holland et al., Cancer Medicine, 3d ed, p1866)
A G-protein-coupled, proteinase-activated receptor that is expressed in a variety of tissues including ENDOTHELIUM; LEUKOCYTES; and the GASTROINTESTINAL TRACT. The receptor is activated by TRYPSIN, which cleaves off the N-terminal peptide from the receptor. The new N-terminal peptide is a cryptic ligand for the receptor. The uncleaved receptor can also be activated by the N-terminal peptide present on the activated THROMBIN RECEPTOR and by small synthetic peptides that contain the unmasked N-terminal sequence.
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).

Evidence suggesting the regulation of a coagulation factor levels in rabbits by a transferable plasma agent. (1/1153)

New Zealand white rabbits were given 30 ml of goat serum intravenously. This procedure resulted in an immediate decrease in platelet count, fibrinogen, and levels of coagulation factors II, V, VII, and X, due to consumption coagulopathy. These factors returned toward baseline levels approximately 12 hr after the injection. Plasma from rabbits who had received goat serum 48 hr previously (donor rabbits) was injected into recipient rabbits. This procedure resulted in a slight rise in the level of coagulation factor II (range, 20%-30%) and a significant rise in factors V (35%-75%), VII (35%-235%), and X (35%-75%) in the recipients. When plasma from control donor rabbits who had not received goat serum was injected into recipients, there was no change in these coagulation factors. It is postulated that the reduction in coagulation factor levels in donor rabbits induces a "coagulopoietin" for each factor or one "coagulopoietin" for all factors which stimulates increased synthesis and/or release of these factors in recipient rabbits.  (+info)

The induction of macrophage spreading: role of coagulation factors and the complement system. (2/1153)

Unstimulated mouse peritoneal macrophages, attached to either glass or plastic substrates, responded to factors generated in serum and plasma by spreading and increasing their apparent surface area up to eightfold. Two distinct and dissociable systems were involved. The first appears related to the distinct and dissociable systems were involved. The first appears related to the contact phase of blood coagulation. It is activated by glass and not plastic surfaces, depleted by kaolin adsorption, and inhibited by soybean trypsin inhibitor. In contrast, a separate complement-dependent system can be generated in kaolin-adsorbed plasma. Activation of the complement system can occur either by the alternate or classical pathways and generates a relatively small effector molecule which is dialyzable. These factors presumably influencing the surface membrane and underlying structures may explain the rapid spreading of activated macrophages observed after both infections and chemical peritoneal inflammatory agents.  (+info)

Reconstitution of the human endothelial cell protein C receptor with thrombomodulin in phosphatidylcholine vesicles enhances protein C activation. (3/1153)

Blocking protein C binding to the endothelial cell protein C receptor (EPCR) on the endothelium is known to reduce protein C activation rates. Now we isolate human EPCR and thrombomodulin (TM) and reconstitute them into phosphatidylcholine vesicles. The EPCR increases protein C activation rates in a concentration-dependent fashion that does not saturate at 14 EPCR molecules/TM. Without EPCR, the protein C concentration dependence fits a single class of sites (Km = 2.17 +/- 0.13 microM). With EPCR, two classes of sites are apparent (Km = 20 +/- 15 nM and Km = 3.2 +/- 1.7 microM). Increasing the EPCR concentration at a constant TM concentration increases the percentage of high affinity sites. Holding the TM:EPCR ratio constant while decreasing the density of these proteins results in a decrease in the EPCR enhancement of protein C activation, suggesting that there is little affinity of the EPCR for TM. Negatively charged phospholipids also enhance protein C activation. EPCR acceleration of protein C activation is blocked by anti-EPCR antibodies, but not by annexin V, whereas the reverse is true with negatively charged phospholipids. Human umbilical cord endothelium expresses approximately 7 times more EPCR than TM. Anti-EPCR antibody reduces protein C activation rates 7-fold over these cells, whereas annexin V is ineffective, indicating that EPCR rather than negatively charged phospholipid provide the surface for protein C activation. EPCR expression varies dramatically among vascular beds. The present results indicate that the EPCR concentration will determine the effectiveness of the protein C activation complex.  (+info)

Carbohydrate on human factor VIII/von Willebrand factor. Impairment of function by removal of specific galactose residues. (4/1153)

Human factor VIII/von Willebrand factor protein containing 120 +/- 12 nmol of sialic acid and 135 +/- 13 nmol of galactose/mg of protein was digested with neuraminidase. The affinity of native factor VIII/von Willebrand factor and its asialo form for the hepatic lectin that specifically binds asialoglycoproteins was assessed from in vitro binding experiments. Native factor VIII/von Willebrand factor exhibited negligible affinity while binding of the asialo derivative was comparable to that observed for asialo-alpha1-acid glycoprotein. Incubation of asialo-factor VIII/von Willebrand factor with Streptococcus pneumoniae beta-galactosidase removed only 62% of the galactose but abolished binding to the purified hepatic lectin. When the asialo derivative was incubated with purified beta-D-galactoside alpha2 leads to 6 sialyltransferase and CMP-[14C]NeuAc, only 61% of the galactose incorporated [14C]NeuAc. From the known specificites of these enzymes, it is concluded that galactose residues important in lectin binding are present in a terminal Gal/beta1 leads to 4GlcNAc sequence on asialo-factor VIII/von Willebrand factor. The relative ristocetin-induced platelet aggregating activity of native, asialo-, and agalacto-factor VIII/von Willebrand factor was 100:38:12, respectively, while procoagulant activity was 100:100:103.  (+info)

Unexpected crucial role of residue 225 in serine proteases. (5/1153)

Residue 225 in serine proteases of the chymotrypsin family is Pro or Tyr in more than 95% of nearly 300 available sequences. Proteases with Y225 (like some blood coagulation and complement factors) are almost exclusively found in vertebrates, whereas proteases with P225 (like degradative enzymes) are present from bacteria to human. Saturation mutagenesis of Y225 in thrombin shows that residue 225 affects ligand recognition up to 60,000-fold. With the exception of Tyr and Phe, all residues are associated with comparable or greatly reduced catalytic activity relative to Pro. The crystal structures of three mutants that differ widely in catalytic activity (Y225F, Y225P, and Y225I) show that although residue 225 makes no contact with substrate, it drastically influences the shape of the water channel around the primary specificity site. The activity profiles obtained for thrombin also suggest that the conversion of Pro to Tyr or Phe documented in the vertebrates occurred through Ser and was driven by a significant gain (up to 50-fold) in catalytic activity. In fact, Ser and Phe are documented in 4% of serine proteases, which together with Pro and Tyr account for almost the entire distribution of residues at position 225. The unexpected crucial role of residue 225 in serine proteases explains the evolutionary selection of residues at this position and shows that the structural determinants of protease activity and specificity are more complex than currently believed. These findings have broad implications in the rational design of enzymes with enhanced catalytic properties.  (+info)

Inflammation, sepsis, and coagulation. (6/1153)

The molecular links between inflammation and coagulation are unquestioned. Inflammation promotes coagulation by leading to intravascular tissue factor expression, eliciting the expression of leukocyte adhesion molecules on the intravascular cell surfaces, and down regulating the fibrinolytic and protein C anticoagulant pathways. Thrombin, in turn, can promote inflammatory responses. This creates a cycle that logically progresses to vascular injury as occurs in septic shock. Most complex systems are regulated by product inhibition. This inflammation-coagulation cycle seems to follow this same principle with the protein C pathway serving as the regulatory mechanism. The molecular basis by which the protein C pathway functions as an anticoagulant is relatively well established compared to the mechanisms involved in regulating inflammation. As one approach to identifying the mechanisms involved in regulating inflammation, we set out to identify novel receptors that could modulate the specificity of APC in a manner analogous to the mechanisms by which thrombomodulin modulates thrombin specificity. This approach led to the identification of an endothelial cell protein C receptor (EPCR). To understand the mechanism, we obtained a crystal structure of APC (lacking the Gla domain). The crystal structure reveals a deep groove in a location analogous to anion binding exosite 1 of thrombin, the location of interaction for thrombomodulin, platelet thrombin receptor and fibrinogen. Thrombomodulin blocks the activation of platelets and fibrinogen without blocking reactivity with chromogenic substrates or inhibitors. Similarly, in solution, EPCR blocks factor Va inactivation without modulating reactivity with protease inhibitors. Thus, these endothelial cell receptors for the protein C system share many properties in common including the ability to be modulated by inflammatory cytokines. Current studies seek to identify the substrate for the APC-EPCR complex as the next step in elucidating the mechanisms by which the protein C pathway modulates the response to injury and inflammation.  (+info)

Regulation and functions of the protein C anticoagulant pathway. (7/1153)

The protein C pathway plays a critical role in the negative regulation of the blood clotting process. We recently identified an endothelial cell receptor for protein C/activated protein C (APC). The receptor is localized almost exclusively on endothelial cells of large vessels and is present at only trace levels or indeed absent from capillaries in most tissues. Patients with sepsis or lupus erythematosus exhibit elevated levels of plasma EPCR which migrates on gels as a single band and is fully capable of binding protein C/APC. There is no correlation with thrombomodulin levels, probably due to different vascular localizations and/or cellular release mechanisms. To understand the mechanisms by which EPCR plasma levels are elevated, we examined EPCR mRNA expression in a rat endotoxin shock model. The EPCR mRNA gene exhibited an early immediate gene response to endotoxin with the mRNA levels increasing nearly 4 fold in the first 3-6 hrs, before returning toward baseline. Plasma levels of EPCR also rose about 4 fold with little change in tissue EPCR levels. Both processes were markedly attenuated by hirudin suggesting that thrombin was responsible for increases in mRNA and plasma EPCR levels. At the level of mRNA, the induction is mediated by a thrombin response element in the 5' flanking region of the gene. Direct thrombin infusion and cell culture experiments support this contention. On endothelium, thrombin is capable of releasing cell surface EPCR and this process is blocked by the metalloproteinase inhibitor orthophenanthroline. Taken together these studies indicate that elevation in soluble plasma EPCR reflects endothelial cell activation in the larger vessels and is likely to be an indication of local thrombin generation near these vessel surfaces.  (+info)

Inhibitory effect of sulfur-containing compounds in Scorodocarpus borneensis Becc. on the aggregation of rabbit platelets. (8/1153)

The inhibitory effects of three pure compounds isolated from wood garlic, 2,4,5-trithiahexane (I), 2,4,5,7-tetrathiaoctane (II), and 2,4,5,7-tetrathiaoctane 2,2-dioxide (III), on rabbit platelet aggregation induced by collagen, arachidonic acid, U46619, ADP (adenosine 5'-diphosphate), PAF (platelet aggregating factor), and thrombin were studied in vitro. The anti-aggregating activity of 2,4,5,7-tetrathiaoctane 4,4-dioxide (IV) was also measured with collagen and arachidonic acid. I, II, III, and IV inhibited the platelet aggregation induced by all tested agonists. I, II, and III exhibited a stronger inhibitory effect against the thrombin-induced aggregation of GFP (gel-filtered platelets) than against the aggregation induced by the other agonists. Notably, the IC50 value for III was 4 microM, which is approximately 2.5 times stronger than MATS (methyl allyl trisulfide), a major anti-platelet compound isolated from garlic. In inhibiting collagen-induced aggregation, II was as potent as MATS and aspirin, with a marked disaggregation effect on the secondary aggregation by arachidonic acid, at the rate of 47.05%/min at a concentration of 10(-4) M. I, II, and III also suppressed U46619-induced aggregation. These results suggest that sulfur-containing compounds in wood garlic not only inhibit arachidonic acid metabolism but also suppress aggregation in association with the function of the platelet plasma membrane.  (+info)

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.

Blood coagulation factors, also known as clotting factors, are a group of proteins that play a crucial role in the blood coagulation process. They are essential for maintaining hemostasis, which is the body's ability to stop bleeding after injury.

There are 13 known blood coagulation factors, and they are designated by Roman numerals I through XIII. These factors are produced in the liver and are normally present in an inactive form in the blood. When there is an injury to a blood vessel, the coagulation process is initiated, leading to the activation of these factors in a specific order.

The coagulation cascade involves two pathways: the intrinsic and extrinsic pathways. The intrinsic pathway is activated when there is damage to the blood vessel itself, while the extrinsic pathway is activated by tissue factor released from damaged tissues. Both pathways converge at the common pathway, leading to the formation of a fibrin clot.

Blood coagulation factors work together in a complex series of reactions that involve activation, binding, and proteolysis. When one factor is activated, it activates the next factor in the cascade, and so on. This process continues until a stable fibrin clot is formed.

Deficiencies or abnormalities in blood coagulation factors can lead to bleeding disorders such as hemophilia or thrombosis. Hemophilia is a genetic disorder that affects one or more of the coagulation factors, leading to excessive bleeding and difficulty forming clots. Thrombosis, on the other hand, occurs when there is an abnormal formation of blood clots in the blood vessels, which can lead to serious complications such as stroke or pulmonary embolism.

Factor XIII, also known as fibrin stabilizing factor, is a protein involved in the clotting process of blood. It is a transglutaminase enzyme that cross-links fibrin molecules to form a stable clot. Factor XIII becomes activated during the coagulation cascade, and its activity helps strengthen the clot and protect it from premature degradation by proteolytic enzymes. A deficiency in Factor XIII can lead to a bleeding disorder characterized by prolonged bleeding after injury or surgery.

Factor IX is also known as Christmas factor, which is a protein that plays a crucial role in the coagulation cascade, a series of chemical reactions that leads to the formation of a blood clot. It is one of the essential components required for the proper functioning of the body's natural blood-clotting mechanism.

Factor IX is synthesized in the liver and activated when it comes into contact with an injured blood vessel. Once activated, it collaborates with other factors to convert factor X to its active form, which then converts prothrombin to thrombin. Thrombin is responsible for converting fibrinogen to fibrin, forming a stable fibrin clot that helps stop bleeding and promote healing.

Deficiencies in Factor IX can lead to hemophilia B, a genetic disorder characterized by prolonged bleeding and an increased risk of spontaneous bleeding. Hemophilia B is inherited in an X-linked recessive pattern, meaning it primarily affects males, while females serve as carriers of the disease. Treatment for hemophilia B typically involves replacing the missing or deficient Factor IX through infusions to prevent or manage bleeding episodes.

Factor X is a protein that is essential for blood clotting, also known as coagulation. It is an enzyme that plays a crucial role in the coagulation cascade, which is a series of chemical reactions that lead to the formation of a blood clot. Factor X is activated by one of two pathways: the intrinsic pathway, which is initiated by damage to the blood vessels, or the extrinsic pathway, which is triggered by the release of tissue factor from damaged cells. Once activated, Factor X converts prothrombin to thrombin, which then converts fibrinogen to fibrin to form a stable clot.

Inherited deficiencies in Factor X can lead to bleeding disorders, while increased levels of Factor X have been associated with an increased risk of thrombosis or blood clots. Therefore, maintaining appropriate levels of Factor X is important for the proper balance between bleeding and clotting in the body.

Factor Xa is a serine protease that plays a crucial role in the coagulation cascade, which is a series of reactions that lead to the formation of a blood clot. It is one of the activated forms of Factor X, a pro-protein that is converted to Factor Xa through the action of other enzymes in the coagulation cascade.

Factor Xa functions as a key component of the prothrombinase complex, which also includes calcium ions, phospholipids, and activated Factor V (also known as Activated Protein C or APC). This complex is responsible for converting prothrombin to thrombin, which then converts fibrinogen to fibrin, forming a stable clot.

Inhibitors of Factor Xa are used as anticoagulants in the prevention and treatment of thromboembolic disorders such as deep vein thrombosis and pulmonary embolism. These drugs work by selectively inhibiting Factor Xa, thereby preventing the formation of the prothrombinase complex and reducing the risk of clot formation.

Factor VII, also known as proconvertin, is a protein involved in the coagulation cascade, which is a series of chemical reactions that leads to the formation of a blood clot. Factor VII is synthesized in the liver and is activated when it comes into contact with tissue factor, which is exposed when blood vessels are damaged. Activated Factor VII then activates Factor X, leading to the formation of thrombin and ultimately a fibrin clot.

Inherited deficiencies or dysfunctions of Factor VII can lead to an increased risk of bleeding, while elevated levels of Factor VII have been associated with an increased risk of thrombosis (blood clots).

Factor VIII is a protein in the blood that is essential for normal blood clotting. It is also known as antihemophilic factor (AHF). Deficiency or dysfunction of this protein results in hemophilia A, a genetic disorder characterized by prolonged bleeding and easy bruising. Factor VIII works together with other proteins to help form a clot and stop bleeding at the site of an injury. It acts as a cofactor for another clotting factor, IX, in the so-called intrinsic pathway of blood coagulation. Intravenous infusions of Factor VIII concentrate are used to treat and prevent bleeding episodes in people with hemophilia A.

Factor XIa is a serine protease enzyme that plays a crucial role in blood coagulation. It is formed through the activation of Factor XI, which is one of the key components in the intrinsic pathway of the coagulation cascade. The activation of Factor XI to Factor XIa occurs via either autoactivation or through the action of thrombin. Once activated, Factor XIa can cleave and activate Factor IX, leading to the formation of Factor IXa, which further amplifies the coagulation cascade.

In summary, Factor XIa is a vital enzyme in the blood coagulation process, contributing to the formation of a stable fibrin clot that helps prevent excessive bleeding during injury or trauma.

Blood coagulation tests, also known as coagulation studies or clotting tests, are a series of medical tests used to evaluate the blood's ability to clot. These tests measure the functioning of various clotting factors and regulatory proteins involved in the coagulation cascade, which is a complex process that leads to the formation of a blood clot to prevent excessive bleeding.

The most commonly performed coagulation tests include:

1. Prothrombin Time (PT): Measures the time it takes for a sample of plasma to clot after the addition of calcium and tissue factor, which activates the extrinsic pathway of coagulation. The PT is reported in seconds and can be converted to an International Normalized Ratio (INR) to monitor anticoagulant therapy.
2. Activated Partial Thromboplastin Time (aPTT): Measures the time it takes for a sample of plasma to clot after the addition of calcium, phospholipid, and a contact activator, which activates the intrinsic pathway of coagulation. The aPTT is reported in seconds and is used to monitor heparin therapy.
3. Thrombin Time (TT): Measures the time it takes for a sample of plasma to clot after the addition of thrombin, which directly converts fibrinogen to fibrin. The TT is reported in seconds and can be used to detect the presence of fibrin degradation products or abnormalities in fibrinogen function.
4. Fibrinogen Level: Measures the amount of fibrinogen, a protein involved in clot formation, present in the blood. The level is reported in grams per liter (g/L) and can be used to assess bleeding risk or the effectiveness of fibrinogen replacement therapy.
5. D-dimer Level: Measures the amount of D-dimer, a protein fragment produced during the breakdown of a blood clot, present in the blood. The level is reported in micrograms per milliliter (µg/mL) and can be used to diagnose or exclude venous thromboembolism (VTE), such as deep vein thrombosis (DVT) or pulmonary embolism (PE).

These tests are important for the diagnosis, management, and monitoring of various bleeding and clotting disorders. They can help identify the underlying cause of abnormal bleeding or clotting, guide appropriate treatment decisions, and monitor the effectiveness of therapy. It is essential to interpret these test results in conjunction with a patient's clinical presentation and medical history.

Thromboplastin is a substance that activates the coagulation cascade, leading to the formation of a clot (thrombus). It's primarily found in damaged or injured tissues and blood vessels, as well as in platelets (thrombocytes). There are two types of thromboplastin:

1. Extrinsic thromboplastin (also known as tissue factor): This is a transmembrane glycoprotein that is primarily found in subendothelial cells and released upon injury to the blood vessels. It initiates the extrinsic pathway of coagulation by binding to and activating Factor VII, ultimately leading to the formation of thrombin and fibrin clots.
2. Intrinsic thromboplastin (also known as plasma thromboplastin or factor III): This term is used less frequently and refers to a labile phospholipid component present in platelet membranes, which plays a role in the intrinsic pathway of coagulation.

In clinical settings, the term "thromboplastin" often refers to reagents used in laboratory tests like the prothrombin time (PT) and activated partial thromboplastin time (aPTT). These reagents contain a source of tissue factor and calcium ions to initiate and monitor the coagulation process.

Factor VIIa is a protein involved in the coagulation cascade, which is a series of chemical reactions that leads to the formation of a blood clot. Factor VIIa is the activated form of factor VII, which is normally activated by tissue factor (TF) when there is damage to the blood vessels. Together, TF and Factor VIIa convert Factor X to its active form, Factor Xa, which then converts prothrombin to thrombin, leading to the formation of a fibrin clot.

In summary, Factor VIIa is an important protein in the coagulation cascade that helps to initiate the formation of a blood clot in response to injury.

Blood coagulation disorders, also known as bleeding disorders or clotting disorders, refer to a group of medical conditions that affect the body's ability to form blood clots properly. Normally, when a blood vessel is injured, the body's coagulation system works to form a clot to stop the bleeding and promote healing.

In blood coagulation disorders, there can be either an increased tendency to bleed due to problems with the formation of clots (hemorrhagic disorder), or an increased tendency for clots to form inappropriately even without injury, leading to blockages in the blood vessels (thrombotic disorder).

Examples of hemorrhagic disorders include:

1. Hemophilia - a genetic disorder that affects the ability to form clots due to deficiencies in clotting factors VIII or IX.
2. Von Willebrand disease - another genetic disorder caused by a deficiency or abnormality of the von Willebrand factor, which helps platelets stick together to form a clot.
3. Liver diseases - can lead to decreased production of coagulation factors, increasing the risk of bleeding.
4. Disseminated intravascular coagulation (DIC) - a serious condition where clotting and bleeding occur simultaneously due to widespread activation of the coagulation system.

Examples of thrombotic disorders include:

1. Factor V Leiden mutation - a genetic disorder that increases the risk of inappropriate blood clot formation.
2. Antithrombin III deficiency - a genetic disorder that impairs the body's ability to break down clots, increasing the risk of thrombosis.
3. Protein C or S deficiencies - genetic disorders that lead to an increased risk of thrombosis due to impaired regulation of the coagulation system.
4. Antiphospholipid syndrome (APS) - an autoimmune disorder where the body produces antibodies against its own clotting factors, increasing the risk of thrombosis.

Treatment for blood coagulation disorders depends on the specific diagnosis and may include medications to manage bleeding or prevent clots, as well as lifestyle changes and monitoring to reduce the risk of complications.

Factor XI, also known as plasma thromboplastin antecedent (PTA) or antihemophilic factor C, is a protein involved in blood coagulation. It is one of the factors in the intrinsic pathway of coagulation, which is activated when blood comes into contact with negatively charged surfaces, such as damaged blood vessels.

When Factor XI is activated (usually by thrombin or activated Factor XII), it activates more Factor XI and also activates Factor IX, leading to the formation of a complex that converts Factor X to its active form, Factor Xa. This ultimately leads to the formation of a fibrin clot and helps to stop bleeding.

Deficiencies in Factor XI can lead to an increased risk of bleeding, although the severity of the bleeding disorder can vary widely among individuals with Factor XI deficiency. Treatment for Factor XI deficiency typically involves replacement therapy with fresh frozen plasma or recombinant Factor XI concentrate.

Factor IXa is a protein that plays a crucial role in the coagulation cascade, which is a series of biochemical reactions involved in blood clotting. It is an activated form of Factor IX, which is one of the coagulation factors that help convert prothrombin to thrombin, leading to the formation of a fibrin clot and stopping bleeding at the site of injury.

Factor IXa works by activating Factor X in the presence of calcium ions, phospholipids, and Factor VIIIa, which is another activated coagulation factor. This complex is called the tenase complex. The activation of Factor X leads to the formation of thrombin, which then converts fibrinogen to fibrin, forming a stable clot.

Deficiencies or dysfunctions in Factor IXa can lead to bleeding disorders such as hemophilia B, also known as Christmas disease, which is characterized by prolonged bleeding times and spontaneous bleeding episodes.

Coagulants are substances that promote the process of coagulation or clotting. They are often used in medical settings to help control bleeding and promote healing. Coagulants work by encouraging the formation of a clot, which helps to stop the flow of blood from a wound or cut.

There are several different types of coagulants that may be used in medical treatments. Some coagulants are naturally occurring substances, such as vitamin K, which is essential for the production of certain clotting factors in the body. Other coagulants may be synthetic or semi-synthetic compounds, such as recombinant activated factor VII (rFVIIa), which is used to treat bleeding disorders and prevent excessive bleeding during surgery.

Coagulants are often administered through injection or infusion, but they can also be applied topically to wounds or cuts. In some cases, coagulants may be used in combination with other treatments, such as compression or cauterization, to help control bleeding and promote healing.

It is important to note that while coagulants can be helpful in controlling bleeding and promoting healing, they can also increase the risk of blood clots and other complications. As a result, they should only be used under the guidance and supervision of a qualified healthcare professional.

Factor V, also known as proaccelerin or labile factor, is a protein involved in the coagulation cascade, which is a series of chemical reactions that leads to the formation of a blood clot. Factor V acts as a cofactor for the activation of Factor X to Factor Xa, which is a critical step in the coagulation cascade.

When blood vessels are damaged, the coagulation cascade is initiated to prevent excessive bleeding. During this process, Factor V is activated by thrombin, another protein involved in coagulation, and then forms a complex with activated Factor X and calcium ions on the surface of platelets or other cells. This complex converts prothrombin to thrombin, which then converts fibrinogen to fibrin to form a stable clot.

Deficiency or dysfunction of Factor V can lead to bleeding disorders such as hemophilia B or factor V deficiency, while mutations in the gene encoding Factor V can increase the risk of thrombosis, as seen in the Factor V Leiden mutation.

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.

Disseminated Intravascular Coagulation (DIC) is a complex medical condition characterized by the abnormal activation of the coagulation cascade, leading to the formation of blood clots in small blood vessels throughout the body. This process can result in the consumption of clotting factors and platelets, which can then lead to bleeding complications. DIC can be caused by a variety of underlying conditions, including sepsis, trauma, cancer, and obstetric emergencies.

The term "disseminated" refers to the widespread nature of the clotting activation, while "intravascular" indicates that the clotting is occurring within the blood vessels. The condition can manifest as both bleeding and clotting complications, which can make it challenging to diagnose and manage.

The diagnosis of DIC typically involves laboratory tests that evaluate coagulation factors, platelet count, fibrin degradation products, and other markers of coagulation activation. Treatment is focused on addressing the underlying cause of the condition while also managing any bleeding or clotting complications that may arise.

Partial Thromboplastin Time (PTT) is a medical laboratory test that measures the time it takes for blood to clot. It's more specifically a measure of the intrinsic and common pathways of the coagulation cascade, which are the series of chemical reactions that lead to the formation of a clot.

The test involves adding a partial thromboplastin reagent (an activator of the intrinsic pathway) and calcium to plasma, and then measuring the time it takes for a fibrin clot to form. This is compared to a control sample, and the ratio of the two times is calculated.

The PTT test is often used to help diagnose bleeding disorders or abnormal blood clotting, such as hemophilia or disseminated intravascular coagulation (DIC). It can also be used to monitor the effectiveness of anticoagulant therapy, such as heparin. Prolonged PTT results may indicate a bleeding disorder or an increased risk of bleeding, while shortened PTT results may indicate a hypercoagulable state and an increased risk of thrombosis.

Prothrombin time (PT) is a medical laboratory test that measures the time it takes for blood to clot. It's often used to evaluate the functioning of the extrinsic and common pathways of the coagulation system, which is responsible for blood clotting. Specifically, PT measures how long it takes for prothrombin (a protein produced by the liver) to be converted into thrombin, an enzyme that converts fibrinogen into fibrin and helps form a clot.

Prolonged PT may indicate a bleeding disorder or a deficiency in coagulation factors, such as vitamin K deficiency or the use of anticoagulant medications like warfarin. It's important to note that PT is often reported with an international normalized ratio (INR), which allows for standardization and comparison of results across different laboratories and reagent types.

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).

Factor XII, also known as Hageman factor, is a protein that plays a role in the coagulation cascade, which is the series of events that leads to the formation of a blood clot. It is one of the zymogens, or inactive precursor proteins, that becomes activated and helps to trigger the coagulation process.

When Factor XII comes into contact with negatively charged surfaces, such as damaged endothelial cells or artificial surfaces like those found on medical devices, it undergoes a conformational change and becomes activated. Activated Factor XII then activates other proteins in the coagulation cascade, including Factor XI, which ultimately leads to the formation of a fibrin clot.

Deficiencies in Factor XII are generally not associated with bleeding disorders, as the coagulation cascade can still proceed through other pathways. However, excessive activation of Factor XII has been implicated in certain thrombotic disorders, such as deep vein thrombosis and disseminated intravascular coagulation (DIC).

Factor V, also known as proaccelerin or labile factor, is a protein involved in the coagulation cascade, which is a series of chemical reactions that leads to the formation of a blood clot. Factor V acts as a cofactor for the conversion of prothrombin to thrombin, which is a critical step in the coagulation process.

Inherited deficiencies or abnormalities in Factor V can lead to bleeding disorders. For example, Factor V Leiden is a genetic mutation that causes an increased risk of blood clots, while Factor V deficiency can cause a bleeding disorder.

It's worth noting that "Factor Va" is not a standard medical term. Factor V becomes activated and turns into Factor Va during the coagulation cascade. Therefore, it is possible that you are looking for the definition of "Factor Va" in the context of its role as an activated form of Factor V in the coagulation process.

Blood coagulation factor inhibitors are substances that interfere with the normal blood clotting process by inhibiting the function of coagulation factors. These inhibitors can be either naturally occurring or artificially produced.

Naturally occurring coagulation factor inhibitors include antithrombin, protein C, and tissue factor pathway inhibitor (TFPI). These inhibitors play a crucial role in regulating the coagulation cascade and preventing excessive clot formation.

Artificially produced coagulation factor inhibitors are used as therapeutic agents to treat thrombotic disorders. Examples include direct oral anticoagulants (DOACs) such as apixaban, rivaroxaban, and dabigatran, which selectively inhibit specific coagulation factors (factor Xa or thrombin).

Additionally, there are also antibodies that can act as coagulation factor inhibitors. These include autoantibodies that develop in some individuals and cause bleeding disorders such as acquired hemophilia A or antiphospholipid syndrome.

Protein C is a vitamin K-dependent protease that functions as an important regulator of coagulation and inflammation. It is a plasma protein produced in the liver that, when activated, degrades clotting factors Va and VIIIa to limit thrombus formation and prevent excessive blood clotting. Protein C also has anti-inflammatory properties by inhibiting the release of pro-inflammatory cytokines and reducing endothelial cell activation. Inherited or acquired deficiencies in Protein C can lead to an increased risk of thrombosis, a condition characterized by abnormal blood clot formation within blood vessels.

Factor VIIIa is a protein that plays a crucial role in the coagulation cascade, which is the series of biochemical reactions involved in blood clotting. Specifically, Factor VIIIa is an activated form of Factor VIII, which is one of the essential clotting factors required for normal hemostasis (the process that stops bleeding).

Factor VIIIa functions as a cofactor for another protein called Factor IXa, and together they form the "tenase complex." This complex activates Factor X to Factor Xa, which ultimately leads to the formation of a fibrin clot.

Deficiencies or dysfunctions in Factor VIII or Factor VIIIa can result in bleeding disorders such as hemophilia A, a genetic condition characterized by prolonged bleeding and spontaneous hemorrhages.

1-Carboxyglutamic acid, also known as γ-carboxyglutamic acid, is a post-translational modification found on certain blood clotting factors and other calcium-binding proteins. It is formed by the carboxylation of glutamic acid residues in these proteins, which enhances their ability to bind to calcium ions. This modification is essential for the proper functioning of many physiological processes, including blood coagulation, bone metabolism, and wound healing.

Hemophilia B is a genetic disorder that affects the body's ability to control blood clotting, also known as coagulation. This condition is caused by a deficiency or dysfunction in Factor IX, one of the proteins essential for normal blood clotting. As a result, people with Hemophilia B experience prolonged bleeding and bruising after injuries, surgeries, or spontaneously, particularly in joints and muscles.

There are different degrees of severity, depending on how much Factor IX is missing or not functioning properly. Mild cases may only become apparent after significant trauma, surgery, or tooth extraction, while severe cases can lead to spontaneous bleeding into joints and muscles, causing pain, swelling, and potential long-term damage. Hemophilia B primarily affects males, as it is an X-linked recessive disorder, but females can be carriers of the condition and may experience mild symptoms.

Vitamin K is a fat-soluble vitamin that plays a crucial role in blood clotting and bone metabolism. It is essential for the production of several proteins involved in blood clotting, including factor II (prothrombin), factor VII, factor IX, and factor X. Additionally, Vitamin K is necessary for the synthesis of osteocalcin, a protein that contributes to bone health by regulating the deposition of calcium in bones.

There are two main forms of Vitamin K: Vitamin K1 (phylloquinone), which is found primarily in green leafy vegetables and some vegetable oils, and Vitamin K2 (menaquinones), which is produced by bacteria in the intestines and is also found in some fermented foods.

Vitamin K deficiency can lead to bleeding disorders such as hemorrhage and excessive bruising. While Vitamin K deficiency is rare in adults, it can occur in newborns who have not yet developed sufficient levels of the vitamin. Therefore, newborns are often given a Vitamin K injection shortly after birth to prevent bleeding problems.

Transglutaminases are a family of enzymes that catalyze the post-translational modification of proteins by forming isopeptide bonds between the carboxamide group of peptide-bound glutamine residues and the ε-amino group of lysine residues. This process is known as transamidation or cross-linking. Transglutaminases play important roles in various biological processes, including cell signaling, differentiation, apoptosis, and tissue repair. There are several types of transglutaminases, such as tissue transglutaminase (TG2), factor XIII, and blood coagulation factor XIIIA. Abnormal activity or expression of these enzymes has been implicated in various diseases, such as celiac disease, neurodegenerative disorders, and cancer.

Hemophilia A is a genetic bleeding disorder caused by a deficiency in clotting factor VIII. This results in impaired blood clotting and prolonged bleeding, particularly after injuries or surgeries. Symptoms can range from mild to severe, with the most severe form resulting in spontaneous bleeding into joints and muscles, leading to pain, swelling, and potential joint damage over time. Hemophilia A primarily affects males, as it is an X-linked recessive disorder, and is usually inherited from a carrier mother. However, about one third of cases result from a spontaneous mutation in the gene for factor VIII. Treatment typically involves replacement therapy with infusions of factor VIII concentrates to prevent or control bleeding episodes.

Antithrombin III is a protein that inhibits the formation of blood clots (thrombi) in the body. It does this by inactivating several enzymes involved in coagulation, including thrombin and factor Xa. Antithrombin III is produced naturally by the liver and is also available as a medication for the prevention and treatment of thromboembolic disorders, such as deep vein thrombosis and pulmonary embolism. It works by binding to and neutralizing excess clotting factors in the bloodstream, thereby reducing the risk of clot formation.

Arcidae is a family of marine bivalves, commonly known as ark clams or angel wings. These bivalves are characterized by their triangular or elongated shells, which are often sculptured with radial ribs and concentric growth lines. They are filter feeders, living buried in the sand or mud and feeding on plankton and organic matter in the water. Arcidae species can be found in both shallow and deep waters, ranging from tropical to polar regions. Some examples of genera within this family include Barbatia, Arca, and Anadara.

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.

Thromboelastography (TEG) is a viscoelastic method used to assess the kinetics of clot formation, clot strength, and fibrinolysis in whole blood. It provides a global assessment of hemostasis by measuring the mechanical properties of a clot as it forms and dissolves over time. The TEG graph displays several parameters that reflect the different stages of clotting, including reaction time (R), clot formation time (K), angle of clot formation (α), maximum amplitude (MA), and percentage lysis at 30 minutes (LY30). These parameters can help guide transfusion therapy and inform decisions regarding the management of coagulopathy in various clinical settings, such as trauma, cardiac surgery, liver transplantation, and obstetrics.

Antithrombins are substances that prevent the formation or promote the dissolution of blood clots (thrombi). They include:

1. Anticoagulants: These are medications that reduce the ability of the blood to clot. Examples include heparin, warfarin, and direct oral anticoagulants (DOACs) such as apixaban, rivaroxaban, and dabigatran.
2. Thrombolytic agents: These are medications that break down existing blood clots. Examples include alteplase, reteplase, and tenecteplase.
3. Fibrinolytics: These are a type of thrombolytic agent that specifically target fibrin, a protein involved in the formation of blood clots.
4. Natural anticoagulants: These are substances produced by the body to regulate blood clotting. Examples include antithrombin III, protein C, and protein S.

Antithrombins are used in the prevention and treatment of various thromboembolic disorders, such as deep vein thrombosis (DVT), pulmonary embolism (PE), stroke, and myocardial infarction (heart attack). It is important to note that while antithrombins can help prevent or dissolve blood clots, they also increase the risk of bleeding, so their use must be carefully monitored.

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.

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.

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.

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.

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.

Vitamin K deficiency is a condition that occurs when the body lacks adequate amounts of Vitamin K, a fat-soluble vitamin essential for blood clotting and bone metabolism. This can lead to an increased risk of excessive bleeding (hemorrhage) and calcification of tissues.

Vitamin K is required for the activation of several proteins involved in blood clotting, known as coagulation factors II, VII, IX, and X. A deficiency in Vitamin K can result in these factors remaining in their inactive forms, leading to impaired blood clotting and an increased risk of bleeding.

Vitamin K deficiency can occur due to several reasons, including malnutrition, malabsorption disorders (such as cystic fibrosis or celiac disease), liver diseases, use of certain medications (such as antibiotics or anticoagulants), and prolonged use of warfarin therapy.

In newborns, Vitamin K deficiency can lead to a serious bleeding disorder known as hemorrhagic disease of the newborn. This is because newborns have low levels of Vitamin K at birth, and their gut bacteria, which are responsible for producing Vitamin K, are not yet fully developed. Therefore, it is recommended that newborns receive a dose of Vitamin K within the first few days of life to prevent this condition.

Symptoms of Vitamin K deficiency can include easy bruising, nosebleeds, bleeding gums, blood in urine or stools, and excessive menstrual bleeding. In severe cases, it can lead to life-threatening hemorrhage. Treatment typically involves administering Vitamin K supplements or injections to replenish the body's levels of this essential nutrient.

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.

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.

Factor XII deficiency, also known as Hageman factor deficiency, is a rare genetic disorder characterized by a lack or dysfunction of coagulation factor XII. This protein is involved in the initiation of the coagulation cascade, which leads to the formation of a blood clot. People with Factor XII deficiency may have an increased risk of bleeding, but it is typically mild and not life-threatening. The diagnosis is usually made through blood tests that measure the level and function of Factor XII. Treatment is generally not necessary unless there is significant bleeding, in which case fresh frozen plasma or cryoprecipitate may be given to provide temporary correction of the deficiency. It's important to note that Factor XII deficiency is not a common cause of bleeding disorders and it doesn't increase the risk of thrombosis.

Fibrinolysis is the natural process in the body that leads to the dissolution of blood clots. It is a vital part of hemostasis, the process that regulates bleeding and wound healing. Fibrinolysis occurs when plasminogen activators convert plasminogen to plasmin, an enzyme that breaks down fibrin, the insoluble protein mesh that forms the structure of a blood clot. This process helps to prevent excessive clotting and maintains the fluidity of the blood. In medical settings, fibrinolysis can also refer to the therapeutic use of drugs that stimulate this process to dissolve unwanted or harmful blood clots, such as those that cause deep vein thrombosis or pulmonary embolism.

Factor XIIa is a protease enzyme that plays a role in the coagulation cascade, which is the series of events that leads to blood clotting. It is formed when Factor XII, also known as Hageman factor, is activated by contact with negatively charged surfaces such as damaged endothelial cells or artificial surfaces like medical devices.

Once activated, Factor XIIa can activate other components of the coagulation cascade, including Factor XI, which ultimately leads to the formation of a fibrin clot. While Factor XIIa is an important part of the coagulation system, it is not essential for normal hemostasis (the process that stops bleeding) in humans, as people with deficiencies in Factor XII do not have an increased risk of bleeding. However, excessive activation of Factor XIIa has been implicated in several pathological conditions, including thrombosis and inflammation.

Whole Blood Coagulation Time (WBCT) is not a standard term used in medical literature. However, I believe you may be referring to "bleeding time" or "coagulation time" which are tests used to evaluate the function of the blood's clotting system.

Bleeding time is a measure of how long it takes for bleeding to stop after a small cut is made in the skin. It helps assess the function of the platelets and the smaller blood vessels.

Coagulation time, on the other hand, measures the time it takes for a larger clot to form in whole blood. This test is not commonly used in clinical practice.

It's important to note that these tests have largely been replaced by more specific coagulation tests, such as prothrombin time (PT) and activated partial thromboplastin time (aPTT), which provide more detailed information about the different components of the clotting system.

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.

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

Blood coagulation disorders, inherited, also known as coagulopathies, are genetic conditions that affect the body's ability to form blood clots in response to injury or damage to blood vessels. These disorders can lead to excessive bleeding or hemorrhage, and in some cases, abnormal clotting.

There are several types of inherited blood coagulation disorders, including:

1. Hemophilia A and B: These are X-linked recessive disorders that affect the production of factors VIII and IX, respectively, which are essential for normal blood clotting. People with hemophilia may experience prolonged bleeding after injury or surgery, and spontaneous bleeding into joints and muscles.
2. Von Willebrand disease: This is the most common inherited coagulation disorder, affecting both men and women. It results from a deficiency or abnormality of von Willebrand factor, a protein that helps platelets stick to damaged blood vessels and assists in the activation of factor VIII. People with von Willebrand disease may experience excessive bleeding after injury, surgery, or dental work.
3. Factor XI deficiency: This is an autosomal recessive disorder that affects the production of factor XI, a protein involved in the intrinsic pathway of blood coagulation. People with factor XI deficiency may have a mild to moderate bleeding tendency, particularly after surgery or trauma.
4. Rare coagulation factor deficiencies: There are several other rare inherited coagulation disorders that affect the production of other clotting factors, such as factors II, V, VII, X, and XIII. These conditions can lead to a range of bleeding symptoms, from mild to severe.

Inherited blood coagulation disorders are usually diagnosed through a combination of medical history, physical examination, and laboratory tests that measure the levels and function of clotting factors in the blood. Treatment may include replacement therapy with purified clotting factor concentrates, medications to control bleeding, and management of bleeding symptoms as they arise.

Serine proteinase inhibitors, also known as serine protease inhibitors or serpins, are a group of proteins that inhibit serine proteases, which are enzymes that cut other proteins in a process called proteolysis. Serine proteinases are important in many biological processes such as blood coagulation, fibrinolysis, inflammation and cell death. The inhibition of these enzymes by serpin proteins is an essential regulatory mechanism to maintain the balance and prevent uncontrolled proteolytic activity that can lead to diseases.

Serpins work by forming a covalent complex with their target serine proteinases, irreversibly inactivating them. The active site of serpins contains a reactive center loop (RCL) that mimics the protease's target protein sequence and acts as a bait for the enzyme. When the protease cleaves the RCL, it gets trapped within the serpin structure, leading to its inactivation.

Serpin proteinase inhibitors play crucial roles in various physiological processes, including:

1. Blood coagulation and fibrinolysis regulation: Serpins such as antithrombin, heparin cofactor II, and protease nexin-2 control the activity of enzymes involved in blood clotting and dissolution to prevent excessive or insufficient clot formation.
2. Inflammation modulation: Serpins like α1-antitrypsin, α2-macroglobulin, and C1 inhibitor regulate the activity of proteases released during inflammation, protecting tissues from damage.
3. Cell death regulation: Some serpins, such as PI-9/SERPINB9, control apoptosis (programmed cell death) by inhibiting granzyme B, a protease involved in this process.
4. Embryonic development and tissue remodeling: Serpins like plasminogen activator inhibitor-1 (PAI-1) and PAI-2 regulate the activity of enzymes involved in extracellular matrix degradation during embryonic development and tissue remodeling.
5. Neuroprotection: Serpins such as neuroserpin protect neurons from damage by inhibiting proteases released during neuroinflammation or neurodegenerative diseases.

Dysregulation of serpins has been implicated in various pathological conditions, including thrombosis, emphysema, Alzheimer's disease, and cancer. Understanding the roles of serpins in these processes may provide insights into potential therapeutic strategies for treating these diseases.

Factor XI deficiency, also known as Hemophilia C or Rosenthal syndrome, is a rare bleeding disorder caused by a deficiency or dysfunction of coagulation factor XI. This protease plays an important role in the intrinsic pathway of blood coagulation. Factor XI deficiency can lead to prolonged bleeding after surgery, trauma, or menstruation, but it typically does not cause spontaneous bleeding like Hemophilia A and B. The severity of the condition varies widely among affected individuals. Inheritance is autosomal recessive, meaning that two defective copies of the gene (one from each parent) are necessary to have the disease.

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.

Factor XIII deficiency, also known as fibrin stabilizing factor deficiency, is a rare bleeding disorder caused by a lack or dysfunction of Factor XIII, a protein involved in the final stage of blood clotting. This deficiency results in impaired clot stability and increased risk of bleeding. Symptoms can include umbilical cord bleeding at birth, prolonged bleeding after circumcision, easy bruising, nosebleeds, muscle bleeds, gastrointestinal bleeds, and excessive menstrual bleeding. Treatment typically involves replacement of the missing Factor XIII through injections, either prophylactically or on-demand to manage bleeding episodes.

Coagulation protein disorders are a group of medical conditions that affect the body's ability to form blood clots properly. These disorders can be caused by genetic defects or acquired factors, such as liver disease or vitamin K deficiency.

The coagulation system is a complex process that involves various proteins called clotting factors. When there is an injury to a blood vessel, these clotting factors work together in a specific order to form a clot and prevent excessive bleeding. In coagulation protein disorders, one or more of these clotting factors are missing or not functioning properly, leading to abnormal bleeding or clotting.

There are several types of coagulation protein disorders, including:

1. Hemophilia: This is a genetic disorder that affects the clotting factor VIII or IX. People with hemophilia may experience prolonged bleeding after injuries, surgery, or dental work.
2. Von Willebrand disease: This is another genetic disorder that affects the von Willebrand factor, a protein that helps platelets stick together and form a clot. People with this condition may have nosebleeds, easy bruising, and excessive bleeding during menstruation or after surgery.
3. Factor XI deficiency: This is a rare genetic disorder that affects the clotting factor XI. People with this condition may experience prolonged bleeding after surgery or trauma.
4. Factor VII deficiency: This is a rare genetic disorder that affects the clotting factor VII. People with this condition may have nosebleeds, easy bruising, and excessive bleeding during menstruation or after surgery.
5. Acquired coagulation protein disorders: These are conditions that develop due to other medical factors, such as liver disease, vitamin K deficiency, or the use of certain medications. These disorders can affect one or more clotting factors and may cause abnormal bleeding or clotting.

Treatment for coagulation protein disorders depends on the specific condition and severity of symptoms. In some cases, replacement therapy with the missing clotting factor may be necessary to prevent excessive bleeding. Other treatments may include medications to control bleeding, such as desmopressin or antifibrinolytic agents, and lifestyle changes to reduce the risk of injury and bleeding.

Thrombin time (TT) is a medical laboratory test that measures the time it takes for a clot to form after thrombin, an enzyme that converts fibrinogen to fibrin in the final step of the coagulation cascade, is added to a plasma sample. This test is used to evaluate the efficiency of the conversion of fibrinogen to fibrin and can be used to detect the presence of abnormalities in the coagulation system, such as the presence of heparin or dysfibrinogenemia. Increased thrombin time may indicate the presence of a systemic anticoagulant or a deficiency in fibrinogen.

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.

Protein S is a vitamin K-dependent protein found in the blood that functions as a natural anticoagulant. It plays a crucial role in regulating the body's clotting system by inhibiting the activation of coagulation factors, thereby preventing excessive blood clotting. Protein S also acts as a cofactor for activated protein C, which is another important anticoagulant protein.

Protein S exists in two forms: free and bound to a protein called C4b-binding protein (C4BP). Only the free form of Protein S has biological activity in inhibiting coagulation. Inherited or acquired deficiencies in Protein S can lead to an increased risk of thrombosis, or abnormal blood clot formation, which can cause various medical conditions such as deep vein thrombosis (DVT) and pulmonary embolism (PE). Regular monitoring of Protein S levels is essential for patients with a history of thrombotic events or those who have a family history of thrombophilia.

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.

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

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.

Hydroxyethyl starch derivatives are modified starches that are used as plasma expanders in medicine. They are created by chemically treating corn, potato, or wheat starch with hydroxylethyl groups, which makes the starch more soluble and less likely to be broken down by enzymes in the body. This results in a large molecule that can remain in the bloodstream for an extended period, increasing intravascular volume and improving circulation.

These derivatives are available in different molecular weights and substitution patterns, which affect their pharmacokinetics and pharmacodynamics. They are used to treat or prevent hypovolemia (low blood volume) due to various causes such as bleeding, burns, or dehydration. Common brand names include Hetastarch, Pentastarch, and Voluven.

It's important to note that the use of hydroxyethyl starch derivatives has been associated with adverse effects, including kidney injury, coagulopathy, and pruritus (severe itching). Therefore, their use should be carefully monitored and restricted to specific clinical situations.

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.

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.

Fibrin(ogen) degradation products (FDPs) are a group of proteins that result from the breakdown of fibrinogen and fibrin, which are key components of blood clots. This process occurs during the normal physiological process of fibrinolysis, where clots are dissolved to maintain blood flow.

FDPs can be measured in the blood as a marker for the activation of the coagulation and fibrinolytic systems. Elevated levels of FDPs may indicate the presence of a disorder that causes abnormal clotting or bleeding, such as disseminated intravascular coagulation (DIC), deep vein thrombosis (DVT), pulmonary embolism (PE), or certain types of cancer.

It is important to note that FDPs are not specific to any particular disorder and their measurement should be interpreted in conjunction with other clinical and laboratory findings.

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

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

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

Phospholipids are a major class of lipids that consist of a hydrophilic (water-attracting) head and two hydrophobic (water-repelling) tails. The head is composed of a phosphate group, which is often bound to an organic molecule such as choline, ethanolamine, serine or inositol. The tails are made up of two fatty acid chains.

Phospholipids are a key component of cell membranes and play a crucial role in maintaining the structural integrity and function of the cell. They form a lipid bilayer, with the hydrophilic heads facing outwards and the hydrophobic tails facing inwards, creating a barrier that separates the interior of the cell from the outside environment.

Phospholipids are also involved in various cellular processes such as signal transduction, intracellular trafficking, and protein function regulation. Additionally, they serve as emulsifiers in the digestive system, helping to break down fats in the diet.

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.

Factor XIIIa is a protein involved in the blood clotting process. It is a activated form of Factor XIII, which is a protransglutaminase enzyme that plays a role in stabilizing blood clots. Factor XIIIa cross-links fibrin molecules in the clot to form a more stable and insoluble clot. This action helps prevent further bleeding from the site of injury.

Factor XIIIa is formed when thrombin, another protein involved in blood clotting, cleaves and activates Factor XIII. Once activated, Factor XIIIa catalyzes the formation of covalent bonds between fibrin molecules, creating a mesh-like structure that strengthens the clot.

Deficiencies or dysfunctions in Factor XIIIa can lead to bleeding disorders, including factor XIII deficiency, which is a rare but serious condition characterized by prolonged bleeding and an increased risk of spontaneous hemorrhage.

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.

Plasma substitutes are fluids that are used to replace the plasma volume in conditions such as hypovolemia (low blood volume) or plasma loss, for example due to severe burns, trauma, or major surgery. They do not contain cells or clotting factors, but they help to maintain intravascular volume and tissue perfusion. Plasma substitutes can be divided into two main categories: crystalloids and colloids.

Crystalloid solutions contain small molecules that can easily move between intracellular and extracellular spaces. Examples include normal saline (0.9% sodium chloride) and lactated Ringer's solution. They are less expensive and have a lower risk of allergic reactions compared to colloids, but they may require larger volumes to achieve the same effect due to their rapid distribution in the body.

Colloid solutions contain larger molecules that tend to stay within the intravascular space for longer periods, thus increasing the oncotic pressure and helping to maintain fluid balance. Examples include albumin, fresh frozen plasma, and synthetic colloids such as hydroxyethyl starch (HES) and gelatin. Colloids may be more effective in restoring intravascular volume, but they carry a higher risk of allergic reactions and anaphylaxis, and some types have been associated with adverse effects such as kidney injury and coagulopathy.

The choice of plasma substitute depends on various factors, including the patient's clinical condition, the underlying cause of plasma loss, and any contraindications or potential side effects of the available products. It is important to monitor the patient's hemodynamic status, electrolyte balance, and coagulation profile during and after the administration of plasma substitutes to ensure appropriate resuscitation and avoid complications.

Factor X deficiency, also known as Stuart-Prower factor deficiency, is a rare bleeding disorder that affects the body's ability to form blood clots. It is caused by a mutation in the gene that provides instructions for making coagulation factor X, a protein involved in the coagulation cascade, which is a series of chemical reactions that lead to the formation of a blood clot.

People with factor X deficiency may experience excessive bleeding after injury or surgery, and they may also have an increased risk of spontaneous bleeding, such as nosebleeds, heavy menstrual periods, and joint bleeds. The severity of the condition can vary widely, from mild to severe, depending on the level of factor X activity in the blood.

Factor X deficiency can be inherited or acquired. Inherited forms of the disorder are caused by mutations in the F10 gene and are usually present at birth. Acquired forms of the disorder can develop later in life due to conditions such as liver disease, vitamin K deficiency, or the use of certain medications that interfere with coagulation.

Treatment for factor X deficiency typically involves replacement therapy with fresh frozen plasma or recombinant factor X concentrates to help restore normal clotting function. In some cases, other treatments such as antifibrinolytic agents or desmopressin may also be used to manage bleeding symptoms.

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

Hypoprothrombinemia is a medical condition characterized by a decreased level of prothrombin (coagulation factor II) in the blood, which can lead to an increased bleeding tendency. Prothrombin is a protein involved in the coagulation cascade that helps to form blood clots and stop bleeding.

Hypoprothrombinemia can be caused by various factors, including vitamin K deficiency, liver disease, inherited or acquired disorders of prothrombin synthesis, or the use of certain medications such as warfarin. Symptoms may include easy bruising, prolonged bleeding from cuts or injuries, nosebleeds, and in severe cases, internal bleeding. Treatment typically involves addressing the underlying cause and may include vitamin K supplementation, fresh frozen plasma transfusions, or other specific therapies depending on the etiology of the condition.

Kaolin is not a medical term per se, but it is a mineral that has various applications in the medical field. Medically, kaolin is used as an ingredient in some over-the-counter (OTC) medications and clinical products, particularly in oral and topical formulations.

Medical definition: Kaolin is a natural hydrated aluminum silicate clay mineral (with the chemical formula Al2Si2O5(OH)4) used in medical applications as an antidiarrheal agent and as a component in various dermatological products for its absorbent, protective, and soothing properties.

Factor V deficiency is a rare bleeding disorder that is caused by a mutation in the gene that produces coagulation factor V, a protein involved in the clotting process. This condition can lead to excessive bleeding following injury or surgery, and may also cause menorrhagia (heavy menstrual periods) in women.

Factor V deficiency is inherited in an autosomal recessive manner, meaning that an individual must inherit two copies of the mutated gene (one from each parent) in order to develop the condition. People who inherit only one copy of the mutated gene are carriers and may have a milder form of the disorder or no symptoms at all.

Treatment for factor V deficiency typically involves replacement therapy with fresh frozen plasma or clotting factor concentrates, which can help to reduce bleeding episodes and prevent complications. In some cases, medications such as desmopressin or antifibrinolytics may also be used to manage the condition.

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.

Factor VII deficiency is a bleeding disorder that is caused by a deficiency or dysfunction of coagulation factor VII, which is a protein involved in the coagulation cascade and is necessary for the initiation of blood clotting. This condition can lead to prolonged bleeding after injury or surgery, easy bruising, and spontaneous bleeding. The severity of the disorder varies widely, depending on the level of factor VII activity. In severe cases, factor VII activity may be less than 1% of normal, leading to a high risk of bleeding. In milder cases, factor VII activity may be between 5-40% of normal, leading to a lower risk of bleeding. Treatment typically involves replacement therapy with fresh frozen plasma or recombinant factor VIIa to control bleeding episodes and prevent complications.

Prekallikrein is a zymogen, or inactive precursor, of the serine protease kallikrein. It is a protein that plays a role in the coagulation cascade and the kinin-kallikrein system. Prekallikrein is primarily produced in the liver and circulates in the bloodstream. When activated, prekallikrein is converted to kallikrein, which then participates in various physiological processes such as blood pressure regulation, inflammation, and fibrinolysis (the breakdown of blood clots). The activation of prekallikrein is facilitated by the surface of negatively charged activators like kininogen or collagen, in conjunction with factor XII (Hageman factor) in a positive feedback loop.

In summary, Prekallikrein is a crucial protein in the coagulation and kinin-kallikrein systems that becomes activated to kallikrein upon contact with negatively charged surfaces and factor XII, contributing to various physiological processes.

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.

Thrombomodulin is a protein that is found on the surface of endothelial cells, which line the interior surface of blood vessels. It plays an important role in the regulation of blood coagulation (clotting) and the activation of natural anticoagulant pathways. Thrombomodulin binds to thrombin, a protein involved in blood clotting, and changes its function from promoting coagulation to inhibiting it. This interaction also activates protein C, an important anticoagulant protein, which helps to prevent the excessive formation of blood clots. Thrombomodulin also has anti-inflammatory properties and is involved in the maintenance of the integrity of the endothelial cell lining.

Hemorrhagic disorders are medical conditions characterized by abnormal bleeding due to impaired blood clotting. This can result from deficiencies in coagulation factors, platelet dysfunction, or the use of medications that interfere with normal clotting processes. Examples include hemophilia, von Willebrand disease, and disseminated intravascular coagulation (DIC). Treatment often involves replacing the missing clotting factor or administering medications to help control bleeding.

Enzyme activation refers to the process by which an enzyme becomes biologically active and capable of carrying out its specific chemical or biological reaction. This is often achieved through various post-translational modifications, such as proteolytic cleavage, phosphorylation, or addition of cofactors or prosthetic groups to the enzyme molecule. These modifications can change the conformation or structure of the enzyme, exposing or creating a binding site for the substrate and allowing the enzymatic reaction to occur.

For example, in the case of proteolytic cleavage, an inactive precursor enzyme, known as a zymogen, is cleaved into its active form by a specific protease. This is seen in enzymes such as trypsin and chymotrypsin, which are initially produced in the pancreas as inactive precursors called trypsinogen and chymotrypsinogen, respectively. Once they reach the small intestine, they are activated by enteropeptidase, a protease that cleaves a specific peptide bond, releasing the active enzyme.

Phosphorylation is another common mechanism of enzyme activation, where a phosphate group is added to a specific serine, threonine, or tyrosine residue on the enzyme by a protein kinase. This modification can alter the conformation of the enzyme and create a binding site for the substrate, allowing the enzymatic reaction to occur.

Enzyme activation is a crucial process in many biological pathways, as it allows for precise control over when and where specific reactions take place. It also provides a mechanism for regulating enzyme activity in response to various signals and stimuli, such as hormones, neurotransmitters, or changes in the intracellular environment.

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.

Fibrinopeptide A is a small protein molecule that is cleaved and released from the larger fibrinogen protein during the blood clotting process. Specifically, it is removed by the enzyme thrombin as part of the conversion of fibrinogen to fibrin, which is the main structural component of a blood clot. The measurement of Fibrinopeptide A in the blood can be used as a marker for ongoing thrombin activation and fibrin formation, which are key events in coagulation and hemostasis. Increased levels of Fibrinopeptide A may indicate abnormal or excessive blood clotting, such as in disseminated intravascular coagulation (DIC) or deep vein thrombosis (DVT).

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.

Hemostatics are substances or agents that promote bleeding cessation or prevent the spread of bleeding. They can act in various ways, such as by stimulating the body's natural clotting mechanisms, constricting blood vessels to reduce blood flow, or forming a physical barrier to block the bleeding site.

Hemostatics are often used in medical settings to manage wounds, injuries, and surgical procedures. They can be applied directly to the wound as a powder, paste, or gauze, or they can be administered systemically through intravenous injection. Examples of hemostatic agents include fibrin sealants, collagen-based products, thrombin, and oxidized regenerated cellulose.

It's important to note that while hemostatics can be effective in controlling bleeding, they should be used with caution and only under the guidance of a healthcare professional. Inappropriate use or overuse of hemostatic agents can lead to complications such as excessive clotting, thrombosis, or tissue damage.

X-ray crystallography is a technique used in structural biology to determine the three-dimensional arrangement of atoms in a crystal lattice. In this method, a beam of X-rays is directed at a crystal and diffracts, or spreads out, into a pattern of spots called reflections. The intensity and angle of each reflection are measured and used to create an electron density map, which reveals the position and type of atoms in the crystal. This information can be used to determine the molecular structure of a compound, including its shape, size, and chemical bonds. X-ray crystallography is a powerful tool for understanding the structure and function of biological macromolecules such as proteins and nucleic acids.

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).

In the context of medicine, plasma refers to the clear, yellowish fluid that is the liquid component of blood. It's composed of water, enzymes, hormones, antibodies, clotting factors, and other proteins. Plasma serves as a transport medium for cells, nutrients, waste products, gases, and other substances throughout the body. Additionally, it plays a crucial role in the immune response and helps regulate various bodily functions.

Plasma can be collected from blood donors and processed into various therapeutic products, such as clotting factors for people with hemophilia or immunoglobulins for patients with immune deficiencies. This process is called plasma fractionation.

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.

Carbon-carbon ligases are a type of enzyme that catalyze the formation of carbon-carbon bonds between two molecules. These enzymes play important roles in various biological processes, including the biosynthesis of natural products and the metabolism of carbohydrates and lipids.

Carbon-carbon ligases can be classified into several categories based on the type of reaction they catalyze. For example, aldolases catalyze the condensation of an aldehyde or ketone with another molecule to form a new carbon-carbon bond and a new carbonyl group. Other examples include the polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs), which are large multienzyme complexes that catalyze the sequential addition of activated carbon units to form complex natural products.

Carbon-carbon ligases are important targets for drug discovery and development, as they play critical roles in the biosynthesis of many disease-relevant molecules. Inhibitors of these enzymes have shown promise as potential therapeutic agents for a variety of diseases, including cancer, infectious diseases, and metabolic disorders.

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.

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.

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.

I'm sorry for any confusion, but the term "Reptilian Proteins" does not have a specific or established medical or scientific meaning. The term "reptilian" generally refers to characteristics of reptiles, and proteins are complex molecules that perform various functions within all living organisms, including reptiles. However, there isn't a recognized category or classification called "Reptilian Proteins" in the field of medicine or biology. If you have any questions about specific reptile-related proteins or reptile physiology, I would be happy to try and help with those!

Alpha-2-antiplasmin (α2AP) is a protein found in the blood plasma that inhibits fibrinolysis, the process by which blood clots are broken down. It does this by irreversibly binding to and inhibiting plasmin, an enzyme that degrades fibrin clots.

Alpha-2-antiplasmin is one of the most important regulators of fibrinolysis, helping to maintain a balance between clot formation and breakdown. Deficiencies or dysfunction in alpha-2-antiplasmin can lead to an increased risk of bleeding due to uncontrolled plasmin activity.

Argon Plasma Coagulation (APC) is a medical procedure that uses ionized argon gas to deliver electrical current and heat to tissue, resulting in coagulation. It is commonly used in the treatment of gastrointestinal bleeding, as well as for cutting and coagulating during surgical procedures. The argon plasma is created by passing argon gas through a high-voltage electrical field, which ionizes the gas and creates a highly precise and controllable plasma beam. This beam can be directed at the tissue to achieve hemostasis (stopping bleeding) or to cut tissue with minimal thermal damage to surrounding structures. The procedure is often performed under endoscopic guidance.

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.

A genetic vector is a vehicle, often a plasmid or a virus, that is used to introduce foreign DNA into a host cell as part of genetic engineering or gene therapy techniques. The vector contains the desired gene or genes, along with regulatory elements such as promoters and enhancers, which are needed for the expression of the gene in the target cells.

The choice of vector depends on several factors, including the size of the DNA to be inserted, the type of cell to be targeted, and the efficiency of uptake and expression required. Commonly used vectors include plasmids, adenoviruses, retroviruses, and lentiviruses.

Plasmids are small circular DNA molecules that can replicate independently in bacteria. They are often used as cloning vectors to amplify and manipulate DNA fragments. Adenoviruses are double-stranded DNA viruses that infect a wide range of host cells, including human cells. They are commonly used as gene therapy vectors because they can efficiently transfer genes into both dividing and non-dividing cells.

Retroviruses and lentiviruses are RNA viruses that integrate their genetic material into the host cell's genome. This allows for stable expression of the transgene over time. Lentiviruses, a subclass of retroviruses, have the advantage of being able to infect non-dividing cells, making them useful for gene therapy applications in post-mitotic tissues such as neurons and muscle cells.

Overall, genetic vectors play a crucial role in modern molecular biology and medicine, enabling researchers to study gene function, develop new therapies, and modify organisms for various purposes.

Thrombophilia is a medical condition characterized by an increased tendency to form blood clots (thrombi) due to various genetic or acquired abnormalities in the coagulation system. These abnormalities can lead to a hypercoagulable state, which can cause thrombosis in both veins and arteries. Commonly identified thrombophilias include factor V Leiden mutation, prothrombin G20210A mutation, antithrombin deficiency, protein C deficiency, and protein S deficiency.

Acquired thrombophilias can be caused by various factors such as antiphospholipid antibody syndrome (APS), malignancies, pregnancy, oral contraceptive use, hormone replacement therapy, and certain medical conditions like inflammatory bowel disease or nephrotic syndrome.

It is essential to diagnose thrombophilia accurately, as it may influence the management of venous thromboembolism (VTE) events and guide decisions regarding prophylactic anticoagulation in high-risk situations.

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

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

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

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.

Epidermal Growth Factor (EGF) is a small polypeptide that plays a significant role in various biological processes, including cell growth, proliferation, differentiation, and survival. It primarily binds to the Epidermal Growth Factor Receptor (EGFR) on the surface of target cells, leading to the activation of intracellular signaling pathways that regulate these functions.

EGF is naturally produced in various tissues, such as the skin, and is involved in wound healing, tissue regeneration, and maintaining the integrity of epithelial tissues. In addition to its physiological roles, EGF has been implicated in several pathological conditions, including cancer, where it can contribute to tumor growth and progression by promoting cell proliferation and survival.

As a result, EGF and its signaling pathways have become targets for therapeutic interventions in various diseases, particularly cancer. Inhibitors of EGFR or downstream signaling components are used in the treatment of several types of malignancies, such as non-small cell lung cancer, colorectal cancer, and head and neck cancer.

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.

Kallikreins are a group of serine proteases, which are enzymes that help to break down other proteins. They are found in various tissues and body fluids, including the pancreas, kidneys, and saliva. In the body, kallikreins play important roles in several physiological processes, such as blood pressure regulation, inflammation, and fibrinolysis (the breakdown of blood clots).

There are two main types of kallikreins: tissue kallikreins and plasma kallikreins. Tissue kallikreins are primarily involved in the activation of kininogen, a protein that leads to the production of bradykinin, a potent vasodilator that helps regulate blood pressure. Plasma kallikreins, on the other hand, play a key role in the coagulation cascade by activating factors XI and XII, which ultimately lead to the formation of a blood clot.

Abnormal levels or activity of kallikreins have been implicated in various diseases, including cancer, cardiovascular disease, and inflammatory disorders. For example, some studies suggest that certain tissue kallikreins may promote tumor growth and metastasis, while others indicate that they may have protective effects against cancer. Plasma kallikreins have also been linked to the development of thrombosis (blood clots) and inflammation in cardiovascular disease.

Overall, kallikreins are important enzymes with diverse functions in the body, and their dysregulation has been associated with various pathological conditions.

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.

Kininogens are a group of proteins found in the blood plasma that play a crucial role in the inflammatory response and blood coagulation. They are precursors to bradykinin, a potent vasodilator and inflammatory mediator. There are two types of kininogens: high molecular weight kininogen (HMWK) and low molecular weight kininogen (LMWK). HMWK is involved in the intrinsic pathway of blood coagulation, while LMWK is responsible for the release of bradykinin. Both kininogens are important targets in the regulation of inflammation and hemostasis.

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.

Lipoproteins are complex particles composed of multiple proteins and lipids (fats) that play a crucial role in the transport and metabolism of fat molecules in the body. They consist of an outer shell of phospholipids, free cholesterols, and apolipoproteins, enclosing a core of triglycerides and cholesteryl esters.

There are several types of lipoproteins, including:

1. Chylomicrons: These are the largest lipoproteins and are responsible for transporting dietary lipids from the intestines to other parts of the body.
2. Very-low-density lipoproteins (VLDL): Produced by the liver, VLDL particles carry triglycerides to peripheral tissues for energy storage or use.
3. Low-density lipoproteins (LDL): Often referred to as "bad cholesterol," LDL particles transport cholesterol from the liver to cells throughout the body. High levels of LDL in the blood can lead to plaque buildup in artery walls and increase the risk of heart disease.
4. High-density lipoproteins (HDL): Known as "good cholesterol," HDL particles help remove excess cholesterol from cells and transport it back to the liver for excretion or recycling. Higher levels of HDL are associated with a lower risk of heart disease.

Understanding lipoproteins and their roles in the body is essential for assessing cardiovascular health and managing risks related to heart disease and stroke.

Protease-activated receptor 1 (PAR-1) is a type of G protein-coupled receptor that is activated by proteolytic cleavage rather than by binding to a ligand in the traditional sense. PAR-1 is expressed on the surface of various cell types, including endothelial cells, smooth muscle cells, and platelets.

When activated by proteases such as thrombin or trypsin, PAR-1 undergoes a conformational change that allows it to interact with G proteins and initiate intracellular signaling pathways. These pathways can lead to a variety of cellular responses, including platelet activation, smooth muscle contraction, and inflammation.

PAR-1 has been implicated in several physiological processes, including hemostasis, thrombosis, and vascular remodeling, as well as in the pathophysiology of various diseases, such as atherosclerosis, cancer, and Alzheimer's disease. Therefore, PAR-1 is an important target for the development of therapeutic agents for these conditions.

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.

Afibrinogenemia is a rare genetic disorder characterized by the complete absence or severely decreased levels of fibrinogen, a protein involved in blood clotting. This condition leads to an increased risk of excessive bleeding due to the inability to form proper blood clots. It is caused by mutations in the genes that provide instructions for making the three chains (Aα, Bβ, and γ) that make up the fibrinogen protein. Inheritance is autosomal recessive, meaning an individual must inherit two copies of the defective gene, one from each parent, to have the condition.

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.

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.

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

Thrombin receptors are a type of G protein-coupled receptor (GPCR) that play a crucial role in hemostasis and thrombosis. They are activated by the protease thrombin, which is generated during the coagulation cascade. There are two main types of thrombin receptors: protease-activated receptor 1 (PAR-1) and PAR-4.

PAR-1 is expressed on various cell types including platelets, endothelial cells, and smooth muscle cells, while PAR-4 is primarily expressed on platelets. Activation of these receptors triggers a variety of intracellular signaling pathways that lead to diverse cellular responses such as platelet activation, aggregation, and secretion; vasoconstriction; and inflammation.

Dysregulation of thrombin receptor signaling has been implicated in several pathological conditions, including arterial and venous thrombosis, atherosclerosis, and cancer. Therefore, thrombin receptors are considered important therapeutic targets for the treatment of these disorders.

Phosphatidylserines are a type of phospholipids that are essential components of the cell membrane, particularly in the brain. They play a crucial role in maintaining the fluidity and permeability of the cell membrane, and are involved in various cellular processes such as signal transduction, protein anchorage, and apoptosis (programmed cell death). Phosphatidylserines contain a polar head group made up of serine amino acids and two non-polar fatty acid tails. They are abundant in the inner layer of the cell membrane but can be externalized to the outer layer during apoptosis, where they serve as signals for recognition and removal of dying cells by the immune system. Phosphatidylserines have been studied for their potential benefits in various medical conditions, including cognitive decline, Alzheimer's disease, and depression.

Warfarin is a anticoagulant medication that works by inhibiting the vitamin K-dependent activation of several coagulation factors (factors II, VII, IX, and X). This results in prolonged clotting times and reduced thrombus formation. It is commonly used to prevent and treat blood clots in conditions such as atrial fibrillation, deep vein thrombosis, and pulmonary embolism. Warfarin is also known by its brand names Coumadin and Jantoven.

It's important to note that warfarin has a narrow therapeutic index, meaning that the difference between an effective dose and a toxic one is small. Therefore, it requires careful monitoring of the patient's coagulation status through regular blood tests (INR) to ensure that the dosage is appropriate and to minimize the risk of bleeding complications.

Antifibrinolytic agents are a class of medications that inhibit the breakdown of blood clots. They work by blocking the action of enzymes called plasminogen activators, which convert plasminogen to plasmin, the main enzyme responsible for breaking down fibrin, a protein that forms the framework of a blood clot.

By preventing the conversion of plasminogen to plasmin, antifibrinolytic agents help to stabilize existing blood clots and prevent their premature dissolution. These medications are often used in clinical settings where excessive bleeding is a concern, such as during or after surgery, childbirth, or trauma.

Examples of antifibrinolytic agents include tranexamic acid, aminocaproic acid, and epsilon-aminocaproic acid. While these medications can be effective in reducing bleeding, they also carry the risk of thromboembolic events, such as deep vein thrombosis or pulmonary embolism, due to their pro-coagulant effects. Therefore, they should be used with caution and only under the close supervision of a healthcare provider.

Thrombophlebitis is a medical condition characterized by the inflammation and clotting of blood in a vein, usually in the legs. The term thrombophlebitis comes from two words: "thrombo" which means blood clot, and "phlebitis" which refers to inflammation of the vein.

The condition can occur in superficial or deep veins. Superficial thrombophlebitis affects the veins just below the skin's surface, while deep vein thrombophlebitis (DVT) occurs in the deeper veins. DVT is a more serious condition as it can lead to complications such as pulmonary embolism if the blood clot breaks off and travels to the lungs.

Symptoms of thrombophlebitis may include redness, warmth, pain, swelling, or discomfort in the affected area. In some cases, there may be visible surface veins that are hard, tender, or ropy to touch. If left untreated, thrombophlebitis can lead to chronic venous insufficiency and other long-term complications. Treatment typically involves medications such as anticoagulants, antiplatelet agents, or thrombolytics, along with compression stockings and other supportive measures.

I'm sorry for any confusion, but "Horseshoe Crabs" are not a medical term or a medical condition. They are actually marine arthropods that have survived for over 450 million years, and are found primarily in the Atlantic Ocean, especially around the Gulf of Mexico and the eastern seaboard of the United States.

However, Horseshoe Crabs do have a significant role in the medical field, particularly in the production of Limulus amebocyte lysate (LAL), which is used to test for bacterial endotoxins in medical equipment and injectable drugs. The blood of Horseshoe Crabs contains amebocytes, which can clot in response to endotoxins found in gram-negative bacteria. This reaction forms a gel-like clot that can be detected and measured, providing a crucial tool for ensuring the sterility of medical products.

So while "Horseshoe Crabs" are not a medical term per se, they do have an important place in medical research and production.

Plasminogen is a glycoprotein that is present in human plasma, and it is the inactive precursor of the enzyme plasmin. Plasmin is a serine protease that plays a crucial role in the dissolution of blood clots by degrading fibrin, one of the major components of a blood clot.

Plasminogen can be activated to form plasmin through the action of various activators, such as tissue plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). Once activated, plasmin can break down fibrin and other proteins, helping to prevent excessive clotting and promoting the normal turnover of extracellular matrix components.

Abnormalities in plasminogen activation have been implicated in various diseases, including thrombosis, fibrosis, and cancer. Therefore, understanding the regulation and function of plasminogen is important for developing therapies to treat these conditions.

Hemodilution is a medical term that refers to the reduction in the concentration of certain components in the blood, usually referring to red blood cells (RBCs) or hemoglobin. This occurs when an individual's plasma volume expands due to the infusion of intravenous fluids or the body's own production of fluid, such as during severe infection or inflammation. As a result, the number of RBCs per unit of blood decreases, leading to a lower hematocrit and hemoglobin level. It is important to note that while hemodilution reduces the concentration of RBCs in the blood, it does not necessarily indicate anemia or blood loss.

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.

Viperidae is not a term that has a medical definition per se, but it is a term used in the field of biology and zoology. Viperidae is the family name for a group of venomous snakes commonly known as vipers. This family includes various types of pit vipers, adders, and rattlesnakes.

While Viperidae itself may not have direct medical relevance, understanding the biology and behavior of these creatures is important in the context of medical fields such as toxicology and emergency medicine. Knowledge about the venomous properties of viper snakes and their potential to cause harm to humans is crucial for appropriate treatment and management of snakebites.

Laser coagulation, also known as laser photocoagulation, is a medical procedure that uses a laser to seal or destroy abnormal blood vessels or tissue. The laser produces a concentrated beam of light that can be precisely focused on the target area. When the laser energy is absorbed by the tissue, it causes the temperature to rise, which leads to coagulation (the formation of a clot) or destruction of the tissue.

In ophthalmology, laser coagulation is commonly used to treat conditions such as diabetic retinopathy, age-related macular degeneration, and retinal tears or holes. The procedure can help to seal leaking blood vessels, reduce fluid leakage, and prevent further vision loss. It is usually performed as an outpatient procedure and may be repeated if necessary.

In other medical specialties, laser coagulation may be used to control bleeding, destroy tumors, or remove unwanted tissue. The specific technique and parameters of the laser treatment will depend on the individual patient's needs and the condition being treated.

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

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

Russell's Viper is not a medical condition or term. It is a type of venomous snake, scientifically known as Daboia russelii, found in parts of Asia. The bite of this viper can cause severe symptoms such as pain, swelling, bleeding, tissue damage, and potentially life-threatening systemic effects like kidney failure, blood clotting problems, and cardiac arrest. Medical personnel should be notified immediately in case of a snakebite, and appropriate antivenom therapy should be initiated as soon as possible to reduce the risk of complications or mortality.

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.

Arthropods are a phylum of animals that includes insects, spiders, crustaceans, and other creatures with jointed appendages. Arthropod proteins, therefore, refer to the proteins that are found in these organisms. These proteins play various roles in the structure, function, and regulation of arthropod cells, tissues, and organs.

Arthropod proteins can be classified into several categories based on their functions, such as structural proteins, enzymes, signaling proteins, and defense proteins. Structural proteins provide support and protection to the arthropod exoskeleton, which is composed mainly of chitin and proteins. Enzymes are proteins that catalyze chemical reactions in arthropod metabolism, while signaling proteins regulate various physiological processes, including growth, development, and reproduction. Defense proteins protect arthropods from pathogens, parasites, and environmental stressors.

Arthropod proteins have attracted significant interest in biomedical research due to their potential applications in drug discovery, vaccine development, and diagnostic tools. For example, some arthropod proteins have been identified as promising targets for the development of new insecticides and antiparasitic drugs. Additionally, arthropod-derived proteins have been used in the production of recombinant vaccines against infectious diseases such as Lyme disease and malaria.

Understanding the structure and function of arthropod proteins is essential for advancing our knowledge of arthropod biology, evolution, and ecology. It also has important implications for human health, agriculture, and environmental conservation.

Venous thrombosis is a medical condition characterized by the formation of a blood clot (thrombus) in the deep veins, often in the legs (deep vein thrombosis or DVT), but it can also occur in other parts of the body such as the arms, pelvis, or lungs (pulmonary embolism).

The formation of a venous thrombus can be caused by various factors, including injury to the blood vessel wall, changes in blood flow, and alterations in the composition of the blood. These factors can lead to the activation of clotting factors and platelets, which can result in the formation of a clot that blocks the vein.

Symptoms of venous thrombosis may include swelling, pain, warmth, and redness in the affected area. In some cases, the clot can dislodge and travel to other parts of the body, causing potentially life-threatening complications such as pulmonary embolism.

Risk factors for venous thrombosis include advanced age, obesity, smoking, pregnancy, use of hormonal contraceptives or hormone replacement therapy, cancer, recent surgery or trauma, prolonged immobility, and a history of previous venous thromboembolism. Treatment typically involves the use of anticoagulant medications to prevent further clotting and dissolve existing clots.

Invertebrate hormones refer to the chemical messengers that regulate various physiological processes in invertebrate animals, which include insects, mollusks, worms, and other animals without a backbone. These hormones are produced by specialized endocrine cells or glands and released into the bloodstream to target organs, where they elicit specific responses that help control growth, development, reproduction, metabolism, and behavior.

Examples of invertebrate hormones include:

1. Ecdysteroids: These are steroid hormones found in arthropods such as insects and crustaceans. They regulate molting (ecdysis) and metamorphosis by stimulating the growth and differentiation of new cuticle layers.
2. Juvenile hormone (JH): This is a sesquiterpenoid hormone produced by the corpora allata glands in insects. JH plays a crucial role in maintaining the juvenile stage, regulating reproduction, and controlling diapause (a period of suspended development during unfavorable conditions).
3. Neuropeptides: These are short chains of amino acids that act as hormones or neurotransmitters in invertebrates. They regulate various functions such as feeding behavior, growth, reproduction, and circadian rhythms. Examples include the neuropeptide F (NPF), which controls food intake and energy balance, and the insulin-like peptides (ILPs) that modulate metabolism and growth.
4. Molluscan cardioactive peptides: These are neuropeptides found in mollusks that regulate heart function by controlling heart rate and contractility. An example is FMRFamide, which has been identified in various mollusk species and influences several physiological processes, including feeding behavior, muscle contraction, and reproduction.
5. Vertebrate-like hormones: Some invertebrates produce hormones that are structurally and functionally similar to those found in vertebrates. For example, some annelids (segmented worms) and cephalopods (squid and octopus) have insulin-like peptides that regulate metabolism and growth, while certain echinoderms (starfish and sea urchins) produce steroid hormones that control reproduction.

In summary, invertebrates utilize various types of hormones to regulate their physiological functions, including neuropeptides, cardioactive peptides, insulin-like peptides, and vertebrate-like hormones. These hormones play crucial roles in controlling growth, development, reproduction, feeding behavior, and other essential processes that maintain homeostasis and ensure survival. Understanding the mechanisms of hormone action in invertebrates can provide valuable insights into the evolution of hormonal systems and their functions across different animal taxa.

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).

Peptide hydrolases, also known as proteases or peptidases, are a group of enzymes that catalyze the hydrolysis of peptide bonds in proteins and peptides. They play a crucial role in various biological processes such as protein degradation, digestion, cell signaling, and regulation of various physiological functions. Based on their catalytic mechanism and the specificity for the peptide bond, they are classified into several types, including serine proteases, cysteine proteases, aspartic proteases, and metalloproteases. These enzymes have important clinical applications in the diagnosis and treatment of various diseases, such as cancer, viral infections, and inflammatory disorders.

Polygeline is a colloidal plasma expander, which is a type of intravenous fluid used to increase blood volume in hypovolemia or shock. It is made up of polyvinylpyrrolidone (PVP) molecules that are cross-linked with divinyl sulfone and then suspended in an electrolyte solution. Polygeline works by drawing water into the circulation, thereby increasing the volume of the plasma.

It is important to note that polygeline has been associated with anaphylactic reactions and therefore should be used with caution. It is also not recommended for use in patients with renal impairment or those who are allergic to PVP. As with any medical treatment, it should only be administered under the direction of a qualified healthcare professional.

Electrocoagulation is a medical procedure that uses heat generated from an electrical current to cause coagulation (clotting) of tissue. This procedure is often used to treat a variety of medical conditions, such as:

* Gastrointestinal bleeding: Electrocoagulation can be used to control bleeding in the stomach or intestines by applying an electrical current to the affected blood vessels, causing them to shrink and clot.
* Skin lesions: Electrocoagulation can be used to remove benign or malignant skin lesions, such as warts, moles, or skin tags, by applying an electrical current to the growth, which causes it to dehydrate and eventually fall off.
* Vascular malformations: Electrocoagulation can be used to treat vascular malformations (abnormal blood vessels) by applying an electrical current to the affected area, causing the abnormal vessels to shrink and clot.

The procedure is typically performed using a specialized device that delivers an electrical current through a needle or probe. The intensity and duration of the electrical current can be adjusted to achieve the desired effect. Electrocoagulation may be used alone or in combination with other treatments, such as surgery or medication.

It's important to note that electrocoagulation is not without risks, including burns, infection, and scarring. It should only be performed by a qualified medical professional who has experience with the procedure.

"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.

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.

Thromboembolism is a medical condition that refers to the obstruction of a blood vessel by a thrombus (blood clot) that has formed elsewhere in the body and then been transported by the bloodstream to a narrower vessel, where it becomes lodged. This process can occur in various parts of the body, leading to different types of thromboembolisms:

1. Deep Vein Thrombosis (DVT): A thrombus forms in the deep veins, usually in the legs or pelvis, and then breaks off and travels to the lungs, causing a pulmonary embolism.
2. Pulmonary Embolism (PE): A thrombus formed elsewhere, often in the deep veins of the legs, dislodges and travels to the lungs, blocking one or more pulmonary arteries. This can lead to shortness of breath, chest pain, and potentially life-threatening complications if not treated promptly.
3. Cerebral Embolism: A thrombus formed in another part of the body, such as the heart or carotid artery, dislodges and travels to the brain, causing a stroke or transient ischemic attack (TIA).
4. Arterial Thromboembolism: A thrombus forms in an artery and breaks off, traveling to another part of the body and blocking blood flow to an organ or tissue, leading to potential damage or loss of function. Examples include mesenteric ischemia (intestinal damage due to blocked blood flow) and retinal artery occlusion (vision loss due to blocked blood flow in the eye).

Prevention, early detection, and appropriate treatment are crucial for managing thromboembolism and reducing the risk of severe complications.

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.

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.

Vitamin K epoxide reductases (VKORs) are enzymes that play a crucial role in the vitamin K cycle, which is essential for the post-translational modification of certain proteins involved in blood coagulation and bone metabolism. Specifically, VKORs reduce vitamin K epoxide back to its active form, vitamin K hydroquinone, allowing it to participate in the carboxylation of these proteins.

The most well-known member of this enzyme family is VKORC1 (Vitamin K Epoxide Reductase Complex Subunit 1), which is the target of the anticoagulant drug warfarin. Warfarin inhibits VKORC1, preventing the reduction of vitamin K epoxide and thereby interfering with the carboxylation of coagulation factors II, VII, IX, and X, as well as proteins C and S. This leads to the production of functionally inactive forms of these proteins and results in the anticoagulant effect of warfarin.

Plasma Kallikrein is a serine protease enzyme that plays a crucial role in the coagulation cascade and kinin-kallikrein system. It's produced as an inactive precursor, known as prekallikrein, which is activated when cleaved by factor XIIa (Hageman factor) into its active form, kallikrein.

Once activated, plasma kallikrein can cleave several substrates, including high-molecular-weight kininogen (HK). This results in the release of bradykinin, a potent vasodilator that contributes to increased vascular permeability and inflammation. Plasma kallikrein also activates factor XII, creating a positive feedback loop that amplifies the coagulation cascade and the kinin-kallikrein system.

Plasma kallikrein is involved in several physiological processes, such as blood pressure regulation, inflammation, and fibrinolysis (the breakdown of blood clots). Dysregulation of plasma kallikrein activity has been implicated in various pathological conditions, including hereditary angioedema, thrombosis, and sepsis.

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

Cadaverine is a foul-smelling organic compound that is produced by the breakdown of certain amino acids in dead bodies. It is formed through the decarboxylation of lysine, an essential amino acid, and is characterized by its strong, unpleasant odor. Cadaverine is often used as a forensic indicator of decomposition and is also being studied for its potential role in various physiological processes, such as inflammation and cancer.

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.

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.

I'm sorry for any confusion, but "Isoflurophate" does not appear to be a recognized term in medical or scientific literature. It is possible that there may be a spelling error or typo in the term you are looking for. If you meant "Isoflurane," which is a commonly used anesthetic in medical and surgical procedures, I can provide a definition for that.

Isoflurane: A volatile halogenated ether liquid used as an inhalational general anesthetic agent. It has a rapid onset and offset of action, making it useful for both induction and maintenance of anesthesia. Isoflurane is also known to have bronchodilatory properties, which can be beneficial in patients with reactive airway disease or asthma.

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.

'Artocarpus' is a genus of trees in the mulberry family (Moraceae). It includes several tropical species that are native to Southeast Asia, such as the jackfruit (*Artocarpus heterophyllus*) and the breadfruit (*Artocarpus altilis*). These trees are known for their large, edible fruits and hard, woody trunks.

The wood of Artocarpus trees is often used for timber, and some species have medicinal properties. For example, the bark of *Artocarpus incisa* has been used in traditional medicine to treat skin diseases and diarrhea. The leaves and fruits of *Artocarpus communis* are also used in traditional medicine in some parts of Asia.

It is important to note that while Artocarpus species have various uses, they should only be used under the guidance of a healthcare professional, as improper use can lead to adverse effects.

"Trimeresurus" is a genus of venomous pit vipers found primarily in Asia. Commonly known as "Asian pit vipers" or " temple pit vipers," these snakes are characterized by the presence of a heat-sensing pit organ between the eye and the nostril, which they use to detect the body heat of their prey. They are responsible for causing serious bites and occasionally fatal accidents in human beings.

It's important to note that "Trimeresurus" is a taxonomic term used in the field of biology, specifically in systematics and classification of organisms. It does not have a direct medical definition, but it refers to a group of snakes with medical significance due to their venomous nature.

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.

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.

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.

Sulfoglycosphingolipids are a type of glycosphingolipid that contain a sulfate ester group in their carbohydrate moiety. They are important components of animal cell membranes and play a role in various biological processes, including cell recognition, signal transduction, and cell adhesion.

The most well-known sulfoglycosphingolipids are the sulfatides, which contain a 3'-sulfate ester on the galactose residue of the glycosphingolipid GalCer (galactosylceramide). Sulfatides are abundant in the nervous system and have been implicated in various neurological disorders.

Other sulfoglycosphingolipids include the seminolipids, which contain a 3'-sulfate ester on the galactose residue of lactosylceramide (Galβ1-4Glcβ1-Cer), and are found in high concentrations in the testis.

Abnormalities in sulfoglycosphingolipid metabolism have been associated with several genetic disorders, such as metachromatic leukodystrophy (MLD) and globoid cell leukodystrophy (GLD), which are characterized by progressive neurological deterioration.

Plasminogen Activator Inhibitor 1 (PAI-1) is a protein involved in the regulation of fibrinolysis, which is the body's natural process of breaking down blood clots. PAI-1 inhibits tissue plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA), two enzymes that convert plasminogen to plasmin, which degrades fibrin clots. Therefore, PAI-1 acts as a natural antagonist of the fibrinolytic system, promoting clot formation and stability. Increased levels of PAI-1 have been associated with thrombotic disorders, such as deep vein thrombosis and pulmonary embolism.

Activated Protein C (APC) resistance is a condition in which the body's natural anticoagulant system is impaired, leading to an increased risk of thrombosis or blood clot formation. APC is an enzyme that plays a crucial role in regulating blood coagulation by inactivating clotting factors Va and VIIIa.

APC resistance is most commonly caused by a genetic mutation in the Factor V gene, known as Factor V Leiden. This mutation results in the production of a variant form of Factor V called Factor V Leiden, which is resistant to APC-mediated inactivation. As a result, the body's ability to regulate blood clotting is impaired, leading to an increased risk of thrombosis.

APC resistance can be measured by performing a functional assay that compares the activity of APC in normal plasma versus plasma from a patient with suspected APC resistance. The assay measures the rate of inactivation of Factor Va by APC, and a reduced rate of inactivation indicates APC resistance.

It is important to note that not all individuals with APC resistance will develop thrombosis, and other factors such as age, obesity, pregnancy, oral contraceptive use, and smoking can increase the risk of thrombosis in individuals with APC resistance.

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

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

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

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.

Calcium chloride is an inorganic compound with the chemical formula CaCl2. It is a white, odorless, and tasteless solid that is highly soluble in water. Calcium chloride is commonly used as a de-icing agent, a desiccant (drying agent), and a food additive to enhance texture and flavor.

In medical terms, calcium chloride can be used as a medication to treat hypocalcemia (low levels of calcium in the blood) or hyperkalemia (high levels of potassium in the blood). It is administered intravenously and works by increasing the concentration of calcium ions in the blood, which helps to regulate various physiological processes such as muscle contraction, nerve impulse transmission, and blood clotting.

However, it is important to note that calcium chloride can have adverse effects if not used properly or in excessive amounts. It can cause tissue irritation, cardiac arrhythmias, and other serious complications. Therefore, its use should be monitored carefully by healthcare professionals.

"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.

Vitamin K Deficiency Bleeding (VKDB) is a condition characterized by an insufficient amount of vitamin K in the body, leading to bleeding complications. It can be further classified into three types:

1. Early onset VKDB: This occurs in the first 24 hours of life and is often seen in infants whose mothers have taken medications that interfere with vitamin K metabolism or who are born prematurely.
2. Classic onset VKDB: This occurs between 2-7 days after birth and is most commonly seen in breastfed infants who have not received vitamin K supplementation at birth.
3. Late onset VKDB: This occurs after the first week of life and can occur up to six months of age. It is often associated with underlying medical conditions that affect vitamin K absorption or metabolism, such as liver disease, cystic fibrosis, or celiac disease.

Symptoms of VKDB may include bleeding from the umbilical cord, gastrointestinal tract, nose, or brain. Treatment typically involves administering vitamin K to stop the bleeding and prevent further complications. Prevention strategies include providing vitamin K supplementation to all newborns at birth.

Protein C deficiency is a genetic disorder that affects the body's ability to control blood clotting. Protein C is a protein in the blood that helps regulate the formation of blood clots. When blood clots form too easily or do not dissolve properly, they can block blood vessels and lead to serious medical conditions such as deep vein thrombosis (DVT) or pulmonary embolism (PE).

People with protein C deficiency have lower than normal levels of this protein in their blood, which can increase their risk of developing abnormal blood clots. The condition is usually inherited and present from birth, but it may not cause any symptoms until later in life, such as during pregnancy, after surgery, or due to other factors that increase the risk of blood clots.

Protein C deficiency can be classified into two types: type I and type II. Type I deficiency is characterized by lower than normal levels of both functional and immunoreactive protein C in the blood. Type II deficiency is characterized by normal or near-normal levels of immunoreactive protein C, but reduced functional activity.

Protein C deficiency can be diagnosed through blood tests that measure the level and function of protein C in the blood. Treatment may include anticoagulant medications to prevent blood clots from forming or dissolve existing ones. Regular monitoring of protein C levels and careful management of risk factors for blood clots are also important parts of managing this condition.

Surgical blood loss is the amount of blood that is lost during a surgical procedure. It can occur through various routes such as incisions, punctures or during the removal of organs or tissues. The amount of blood loss can vary widely depending on the type and complexity of the surgery being performed.

Surgical blood loss can be classified into three categories:

1. Insensible losses: These are small amounts of blood that are lost through the skin, respiratory tract, or gastrointestinal tract during surgery. They are not usually significant enough to cause any clinical effects.
2. Visible losses: These are larger amounts of blood that can be seen and measured directly during surgery. They may require transfusion or other interventions to prevent hypovolemia (low blood volume) and its complications.
3. Hidden losses: These are internal bleeding that cannot be easily seen or measured during surgery. They can occur in the abdominal cavity, retroperitoneal space, or other areas of the body. They may require further exploration or imaging studies to diagnose and manage.

Surgical blood loss can lead to several complications such as hypovolemia, anemia, coagulopathy (disorders of blood clotting), and organ dysfunction. Therefore, it is essential to monitor and manage surgical blood loss effectively to ensure optimal patient outcomes.

A blood transfusion is a medical procedure in which blood or its components are transferred from one individual (donor) to another (recipient) through a vein. The donated blood can be fresh whole blood, packed red blood cells, platelets, plasma, or cryoprecipitate, depending on the recipient's needs. Blood transfusions are performed to replace lost blood due to severe bleeding, treat anemia, support patients undergoing major surgeries, or manage various medical conditions such as hemophilia, thalassemia, and leukemia. The donated blood must be carefully cross-matched with the recipient's blood type to minimize the risk of transfusion reactions.

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

Examples of biological models include:

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

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

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.

SERPINs are an acronym for "serine protease inhibitors." They are a group of proteins that inhibit serine proteases, which are enzymes that cut other proteins. SERPINs are found in various tissues and body fluids, including blood, and play important roles in regulating biological processes such as inflammation, blood clotting, and cell death. They do this by forming covalent complexes with their target proteases, thereby preventing them from carrying out their proteolytic activities. Mutations in SERPIN genes have been associated with several genetic disorders, including emphysema, cirrhosis, and dementia.

Chromogenic compounds are substances that can be converted into a colored product through a chemical reaction. These compounds are often used in various diagnostic tests, including microbiological assays and immunoassays, to detect the presence or absence of a specific analyte (such as a particular bacterium, enzyme, or antigen).

In these tests, a chromogenic substrate is added to the sample, and if the target analyte is present, it will react with the substrate and produce a colored product. The intensity of the color can often be correlated with the amount of analyte present in the sample, allowing for quantitative analysis.

Chromogenic compounds are widely used in clinical laboratories because they offer several advantages over other types of diagnostic tests. They are typically easy to use and interpret, and they can provide rapid results with high sensitivity and specificity. Additionally, chromogenic assays can be automated, which can help increase throughput and reduce the potential for human error.

"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.

Strongylida is an order of parasitic roundworms, also known as nematodes. These parasites are primarily found in the gastrointestinal tracts of various hosts, including mammals, birds, and reptiles. Strongylida species have a complex life cycle that involves both free-living and parasitic stages. They are known for their strong epidemiological significance, as they can cause significant disease burden and production losses in livestock industries worldwide.

Some well-known Strongylida genera include:

* Strongyloides (threadworms)
* Ancylostoma (hookworms)
* Necator (hookworms)
* Ostertagia (brown stomach worms)
* Haemonchus (barber's pole worms)

These parasites can cause a range of clinical signs, depending on the species and intensity of infection. Common symptoms include diarrhea, anemia, weight loss, and decreased productivity in affected animals. In humans, Strongyloides species can cause strongyloidiasis, which may present as cutaneous larva migrans or intestinal infection, with potential dissemination to various organs in severe cases.

Ellagic acid is a type of polyphenol, which is a class of organic compounds characterized by the presence of multiple phenol units. It is found in various fruits and vegetables, including raspberries, strawberries, pomegranates, and walnuts. Ellagic acid has been studied for its potential antioxidant, anti-inflammatory, and chemopreventive properties. However, more research is needed to confirm these effects and establish a clear medical definition of ellagic acid. It is not considered a medication or a treatment for any specific medical condition.

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.

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

Cephapirin is a type of antibiotic that belongs to the class of cephalosporins. It is used to treat various bacterial infections, including respiratory tract infections, skin and soft tissue infections, bone and joint infections, and genitourinary tract infections. Cephapirin works by interfering with the bacteria's ability to form a cell wall, which results in bacterial death.

Like other cephalosporins, cephapirin is generally well-tolerated and has a broad spectrum of activity against many different types of bacteria. However, it may cause side effects such as nausea, diarrhea, vomiting, and allergic reactions in some people. It is important to take cephapirin exactly as directed by a healthcare provider, and to complete the full course of treatment even if symptoms improve before all of the medication has been taken.

It's worth noting that Cephapirin is not a commonly used antibiotic now a days, due to the availability of other cephalosporins which are more effective and have less side effects.

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.

Substrate specificity in the context of medical biochemistry and enzymology refers to the ability of an enzyme to selectively bind and catalyze a chemical reaction with a particular substrate (or a group of similar substrates) while discriminating against other molecules that are not substrates. This specificity arises from the three-dimensional structure of the enzyme, which has evolved to match the shape, charge distribution, and functional groups of its physiological substrate(s).

Substrate specificity is a fundamental property of enzymes that enables them to carry out highly selective chemical transformations in the complex cellular environment. The active site of an enzyme, where the catalysis takes place, has a unique conformation that complements the shape and charge distribution of its substrate(s). This ensures efficient recognition, binding, and conversion of the substrate into the desired product while minimizing unwanted side reactions with other molecules.

Substrate specificity can be categorized as:

1. Absolute specificity: An enzyme that can only act on a single substrate or a very narrow group of structurally related substrates, showing no activity towards any other molecule.
2. Group specificity: An enzyme that prefers to act on a particular functional group or class of compounds but can still accommodate minor structural variations within the substrate.
3. Broad or promiscuous specificity: An enzyme that can act on a wide range of structurally diverse substrates, albeit with varying catalytic efficiencies.

Understanding substrate specificity is crucial for elucidating enzymatic mechanisms, designing drugs that target specific enzymes or pathways, and developing biotechnological applications that rely on the controlled manipulation of enzyme activities.

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.

Streptomycetaceae is a family of bacteria belonging to the order Actinomycetales. These bacteria are gram-positive, aerobic, and have a filamentous morphology that can resemble fungi. They are known for their ability to produce a wide variety of antibiotics and other secondary metabolites, making them important sources of drugs used in medicine and agriculture. Streptomycetaceae species are commonly found in soil and decaying vegetation, where they play important roles in nutrient cycling and decomposition.

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

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.

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.

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

Tosylarginine Methyl Ester (TAME) is not a medication or a therapeutic agent, but it is a research compound used in scientific studies. It is a synthetic molecule that is often used as a control or a reference standard in enzyme inhibition assays. TAME is an esterified form of the amino acid arginine, with a tosyl group (p-toluenesulfonyl) attached to the nitrogen atom.

TAME is specifically used as a selective and reversible inhibitor of the enzyme called butyrylcholinesterase (BChE), which is involved in the breakdown of certain neurotransmitters in the body. By inhibiting BChE, TAME can help to increase the levels of these neurotransmitters in the brain, making it a useful tool for studying the mechanisms of this enzyme and its role in various physiological processes.

It's important to note that while TAME is used in research settings, it is not approved for use as a drug or therapeutic agent in humans or animals.

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.

Proteinase-activated receptors (PARs) are a subfamily of G protein-coupled receptors that are activated by proteolytic cleavage of their extracellular N-terminal domain. This process exposes a new tethered ligand domain that binds to the receptor and activates it.

There are four known PARs (PAR-1, PAR-2, PAR-3, and PAR-4) that play important roles in various physiological and pathophysiological processes, including inflammation, hemostasis, wound healing, and cancer. Proteinases such as thrombin, trypsin, and matrix metalloproteinases can activate PARs, leading to the activation of downstream signaling pathways that regulate cellular responses such as proliferation, migration, and gene expression.

Proteinase-activated receptors have been identified as important drug targets for various diseases, including thrombosis, inflammation, and cancer. Inhibitors or antagonists of PARs have shown promise in preclinical and clinical studies for the treatment of these conditions.

Endopeptidases are a type of enzyme that breaks down proteins by cleaving peptide bonds inside the polypeptide chain. They are also known as proteinases or endoproteinases. These enzymes work within the interior of the protein molecule, cutting it at specific points along its length, as opposed to exopeptidases, which remove individual amino acids from the ends of the protein chain.

Endopeptidases play a crucial role in various biological processes, such as digestion, blood coagulation, and programmed cell death (apoptosis). They are classified based on their catalytic mechanism and the structure of their active site. Some examples of endopeptidase families include serine proteases, cysteine proteases, aspartic proteases, and metalloproteases.

It is important to note that while endopeptidases are essential for normal physiological functions, they can also contribute to disease processes when their activity is unregulated or misdirected. For instance, excessive endopeptidase activity has been implicated in the pathogenesis of neurodegenerative disorders, cancer, and inflammatory conditions.

The umbilical veins are blood vessels in the umbilical cord that carry oxygenated and nutrient-rich blood from the mother to the developing fetus during pregnancy. There are typically two umbilical veins, one of which usually degenerates and becomes obliterated, leaving a single functional vein. This remaining vein is known as the larger umbilical vein or the venous duct. It enters the fetal abdomen through the umbilicus and passes through the liver, where it branches off to form the portal sinus. Ultimately, the blood from the umbilical vein mixes with the blood from the inferior vena cava and is pumped to the heart through the right atrium.

It's important to note that after birth, the umbilical veins are no longer needed and undergo involution, becoming the ligamentum teres in the adult.

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

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

Examples of animal disease models include:

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

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

Protease inhibitors are a class of antiviral drugs that are used to treat infections caused by retroviruses, such as the human immunodeficiency virus (HIV), which is responsible for causing AIDS. These drugs work by blocking the activity of protease enzymes, which are necessary for the replication and multiplication of the virus within infected cells.

Protease enzymes play a crucial role in the life cycle of retroviruses by cleaving viral polyproteins into functional units that are required for the assembly of new viral particles. By inhibiting the activity of these enzymes, protease inhibitors prevent the virus from replicating and spreading to other cells, thereby slowing down the progression of the infection.

Protease inhibitors are often used in combination with other antiretroviral drugs as part of highly active antiretroviral therapy (HAART) for the treatment of HIV/AIDS. Common examples of protease inhibitors include saquinavir, ritonavir, indinavir, and atazanavir. While these drugs have been successful in improving the outcomes of people living with HIV/AIDS, they can also cause side effects such as nausea, diarrhea, headaches, and lipodystrophy (changes in body fat distribution).

A postmature infant is a newborn who is delivered at or after 42 weeks (294 days) of gestation. These infants are also known as "post-term" or "post-dates." At this stage, the placenta may not function optimally, leading to potential issues such as decreased fetal movement, meconium staining of amniotic fluid, and low birth weight. Postmature infants may require close monitoring and evaluation after delivery to ensure their well-being.

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

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

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

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

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

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

Viscoelastic substances are materials that exhibit both viscous and elastic properties when undergoing deformation. In the context of medicine, viscoelastic substances are often used to describe certain biological fluids, such as synovial fluid found in joints, or the vitreous humor in the eye. These fluids have a complex structure that allows them to behave as a liquid and a solid simultaneously, providing resistance to sudden force while also allowing for smooth movement over time.

Artificial viscoelastic substances are also used in medical applications, such as in surgical sealants and hemostatic agents, which are designed to control bleeding by forming a gel-like substance that fills wounds and helps to promote clotting. These materials have unique properties that allow them to conform to the shape of the wound and provide sustained pressure to help stop bleeding.

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

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

Lymphangiosarcoma is a rare and aggressive type of soft tissue cancer that originates from the lymphatic vessels. It primarily affects the skin, particularly in patients who have had long-standing lymphedema (chronic swelling of a body part due to lymph fluid accumulation). The condition is also known as Stewart-Treves syndrome when it occurs in the upper limb of postmastectomy lymphedematous extremities.

Lymphangiosarcoma is characterized by the proliferation of malignant cells within the walls of the lymphatic vessels, leading to the formation of tumors that can ulcerate and bleed. The cancer can metastasize (spread) to other parts of the body, such as the lungs and liver, making it a serious and life-threatening condition.

The diagnosis of lymphangiosarcoma typically involves a combination of clinical examination, imaging studies, and biopsy. Treatment usually includes surgical resection of the tumor, followed by radiation therapy and chemotherapy to reduce the risk of recurrence and metastasis. However, due to its rarity and aggressiveness, lymphangiosarcoma has a poor prognosis, with a low survival rate.

Proteinase-activated receptor 2 (PAR-2) is a type of G protein-coupled receptor that is widely expressed in various tissues, including the respiratory and gastrointestinal tracts, skin, and nervous system. PAR-2 can be activated by serine proteases such as trypsin, mast cell tryptase, and thrombin, which cleave the N-terminal extracellular domain of the receptor to expose a tethered ligand that binds to and activates the receptor.

Once activated, PAR-2 signaling can lead to a variety of cellular responses, including inflammation, pain, and altered ion channel activity. PAR-2 has been implicated in several physiological and pathophysiological processes, such as airway hyperresponsiveness, asthma, cough, gastrointestinal motility disorders, and skin disorders.

In summary, PAR-2 is a type of receptor that can be activated by serine proteases, leading to various cellular responses and involvement in several disease processes.

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.

Polyphosphates are compounds consisting of many phosphate groups linked together in the form of chains or rings. They are often used in various medical and healthcare applications, such as:

* Dental care products: Polyphosphates can help prevent the formation of dental plaque and calculus by binding to calcium ions in saliva and inhibiting the growth of bacteria that cause tooth decay.
* Nutritional supplements: Polyphosphates are sometimes used as a source of phosphorus in nutritional supplements, particularly for people who have kidney disease or other medical conditions that require them to limit their intake of phosphorus from food sources.
* Medical devices: Polyphosphates may be used in the manufacture of medical devices, such as contact lenses and catheters, to improve their biocompatibility and resistance to bacterial growth.

It's worth noting that while polyphosphates have various medical uses, they can also be found in many non-medical products, such as food additives, water treatment chemicals, and cleaning agents.

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.

'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.

Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification to become active. These modifications typically include cleavage of the precursor protein by specific enzymes, resulting in the release of the active protein. This process allows for the regulation and control of protein activity within the body. Protein precursors can be found in various biological processes, including the endocrine system where they serve as inactive hormones that can be converted into their active forms when needed.

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.

A blood component transfusion is the process of transferring a specific component of donated blood into a recipient's bloodstream. Blood components include red blood cells, plasma, platelets, and cryoprecipitate (a fraction of plasma that contains clotting factors). These components can be separated from whole blood and stored separately to allow for targeted transfusions based on the individual needs of the patient.

For example, a patient who is anemic may only require a red blood cell transfusion, while a patient with severe bleeding may need both red blood cells and plasma to replace lost volume and clotting factors. Platelet transfusions are often used for patients with low platelet counts or platelet dysfunction, and cryoprecipitate is used for patients with factor VIII or fibrinogen deficiencies.

Blood component transfusions must be performed under strict medical supervision to ensure compatibility between the donor and recipient blood types and to monitor for any adverse reactions. Proper handling, storage, and administration of blood components are also critical to ensure their safety and efficacy.

Hydrolysis is a chemical process, not a medical one. However, it is relevant to medicine and biology.

Hydrolysis is the breakdown of a chemical compound due to its reaction with water, often resulting in the formation of two or more simpler compounds. In the context of physiology and medicine, hydrolysis is a crucial process in various biological reactions, such as the digestion of food molecules like proteins, carbohydrates, and fats. Enzymes called hydrolases catalyze these hydrolysis reactions to speed up the breakdown process in the body.

Battered Child Syndrome is a medical condition in which a child has been physically abused and harmed, often over a period of time. It is also known as Non-accidental Injury (NAI) or Inflicted Traumatic Injury. The syndrome is characterized by a pattern of injuries, including bruises, fractures, burns, and internal injuries, which are not consistent with the history provided by the caregiver.

The symptoms of Battered Child Syndrome may include:

1. Unexplained or inconsistent explanations for injuries
2. Multiple injuries in various stages of healing
3. Injuries to different parts of the body, such as the ears, mouth, and genitals
4. Frequent visits to the emergency department or doctor's office for treatment of injuries
5. Delayed seeking of medical attention for serious injuries
6. Behavioral changes, such as fearfulness, regression, or aggression
7. Developmental delays or learning difficulties
8. Failure to thrive (poor growth and weight gain)

The diagnosis of Battered Child Syndrome is made by a healthcare professional based on the history, physical examination, and any diagnostic tests that may be necessary. The syndrome is a serious form of child abuse that requires immediate intervention and protection for the child. Treatment typically involves medical care for injuries, counseling and support for the child and family, and reporting the abuse to child protective services or law enforcement agencies.

Cell-derived microparticles (CDMs), also known as microvesicles or microparticles, are small membrane-bound particles that are released from the cell surface upon activation or apoptosis of various cell types, including platelets, leukocytes, endothelial cells, and red blood cells. CDMs range in size from 0.1 to 1.0 micrometers in diameter and contain a variety of bioactive molecules, such as lipids, proteins, and nucleic acids, which can be transferred to neighboring or distant cells, thereby modulating their function.

CDMs have been implicated in various physiological and pathological processes, including coagulation, inflammation, immune response, angiogenesis, and cancer progression. They have also emerged as potential biomarkers for various diseases, such as cardiovascular disease, sepsis, and cancer, due to their distinct molecular signature and abundance in body fluids, such as blood, urine, and cerebrospinal fluid.

The mechanisms of CDM formation and release are complex and involve several cellular processes, including cytoskeletal rearrangement, membrane budding, and vesicle shedding. The molecular composition of CDMs reflects their cellular origin and activation state, and can be analyzed by various techniques, such as flow cytometry, proteomics, and transcriptomics, to gain insights into their biological functions and clinical relevance.

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

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

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

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

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

Plasminogen inactivators are substances that inhibit the activity of plasminogen, a proenzyme that is converted into the active enzyme plasmin. Plasmin plays a crucial role in the breakdown of blood clots by cleaving fibrin, the protein that forms the structural framework of a clot.

There are two main types of plasminogen activators: tissue plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). These enzymes convert plasminogen into plasmin, thereby promoting fibrinolysis, or the dissolution of blood clots. Plasminogen inactivators, on the other hand, inhibit this process by blocking the conversion of plasminogen to plasmin.

Plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator inhibitor-2 (PAI-2) are two main types of plasminogen inactivators. PAI-1 is a serine protease inhibitor that inactivates tPA and uPA by forming covalent complexes with them. PAI-1 is produced by various cells, including endothelial cells, hepatocytes, and adipocytes. Elevated levels of PAI-1 have been associated with an increased risk of thrombosis and cardiovascular disease.

PAI-2 is another serine protease inhibitor that primarily inhibits uPA. It is produced by various cells, including monocytes, macrophages, and trophoblasts. PAI-2 has been shown to play a role in pregnancy, immune response, and cancer.

Overall, plasminogen inactivators are important regulators of the fibrinolytic system, which helps maintain blood flow and prevent excessive clotting or bleeding. Dysregulation of this system can lead to various pathological conditions, such as thrombosis, hemorrhage, and cancer.

Arginine is an α-amino acid that is classified as a semi-essential or conditionally essential amino acid, depending on the developmental stage and health status of the individual. The adult human body can normally synthesize sufficient amounts of arginine to meet its needs, but there are certain circumstances, such as periods of rapid growth or injury, where the dietary intake of arginine may become necessary.

The chemical formula for arginine is C6H14N4O2. It has a molecular weight of 174.20 g/mol and a pKa value of 12.48. Arginine is a basic amino acid, which means that it contains a side chain with a positive charge at physiological pH levels. The side chain of arginine is composed of a guanidino group, which is a functional group consisting of a nitrogen atom bonded to three methyl groups.

In the body, arginine plays several important roles. It is a precursor for the synthesis of nitric oxide, a molecule that helps regulate blood flow and immune function. Arginine is also involved in the detoxification of ammonia, a waste product produced by the breakdown of proteins. Additionally, arginine can be converted into other amino acids, such as ornithine and citrulline, which are involved in various metabolic processes.

Foods that are good sources of arginine include meat, poultry, fish, dairy products, nuts, seeds, and legumes. Arginine supplements are available and may be used for a variety of purposes, such as improving exercise performance, enhancing wound healing, and boosting immune function. However, it is important to consult with a healthcare provider before taking arginine supplements, as they can interact with certain medications and have potential side effects.

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.

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.

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.

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.

"Bothrops" is a genus of venomous snakes commonly known as lancehead vipers, found primarily in Central and South America. The name "Bothrops" comes from the Greek words "bothros," meaning pit, and "ops," meaning face, referring to the deep pits on the sides of their heads that help them detect heat and locate prey. These snakes are known for their aggressive behavior and potent venom, which can cause severe pain, swelling, tissue damage, and potentially life-threatening systemic effects if left untreated.

The genus "Bothrops" includes over 30 species of pit vipers, many of which are considered medically important due to their ability to inflict serious envenomations in humans. Some notable examples include Bothrops asper (the terciopelo or fer-de-lance), Bothrops atrox (the common lancehead), and Bothrops jararaca (the jararaca).

If you encounter a snake of this genus, it is essential to seek medical attention immediately if bitten, as the venom can cause significant harm if not treated promptly.

Salivary proteins and peptides refer to the diverse group of molecules that are present in saliva, which is the clear, slightly alkaline fluid produced by the salivary glands in the mouth. These proteins and peptides play a crucial role in maintaining oral health and contributing to various physiological functions.

Some common types of salivary proteins and peptides include:

1. **Mucins**: These are large, heavily glycosylated proteins that give saliva its viscous quality. They help to lubricate the oral cavity, protect the mucosal surfaces, and aid in food bolus formation.
2. **Amylases**: These enzymes break down carbohydrates into simpler sugars, initiating the digestive process even before food reaches the stomach.
3. **Proline-rich proteins (PRPs)**: PRPs contribute to the buffering capacity of saliva and help protect against tooth erosion by forming a protective layer on tooth enamel.
4. **Histatins**: These are small cationic peptides with antimicrobial properties, playing a significant role in maintaining oral microbial homeostasis and preventing dental caries.
5. **Lactoferrin**: An iron-binding protein that exhibits antibacterial, antifungal, and anti-inflammatory activities, contributing to the overall oral health.
6. **Statherin and Cystatins**: These proteins regulate calcium phosphate precipitation, preventing dental calculus formation and maintaining tooth mineral homeostasis.

Salivary proteins and peptides have attracted significant interest in recent years due to their potential diagnostic and therapeutic applications. Alterations in the composition of these molecules can provide valuable insights into various oral and systemic diseases, making them promising biomarkers for disease detection and monitoring.

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

Elapid venoms are the toxic secretions produced by elapid snakes, a family of venomous snakes that includes cobras, mambas, kraits, and coral snakes. These venoms are primarily composed of neurotoxins, which can cause paralysis and respiratory failure in prey or predators.

Elapid venoms work by targeting the nervous system, disrupting communication between the brain and muscles. This results in muscle weakness, paralysis, and eventually respiratory failure if left untreated. Some elapid venoms also contain hemotoxins, which can cause tissue damage, bleeding, and other systemic effects.

The severity of envenomation by an elapid snake depends on several factors, including the species of snake, the amount of venom injected, the location of the bite, and the size and health of the victim. Prompt medical treatment is essential in cases of elapid envenomation, as the effects of the venom can progress rapidly and lead to serious complications or death if left untreated.

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.

"Light coagulation," also known as "laser coagulation," is a medical term that refers to the use of laser technology to cauterize (seal or close) tissue. This procedure uses heat generated by a laser to cut, coagulate, or destroy tissue. In light coagulation, the laser beam is focused on the blood vessels in question, causing the blood within them to clot and the vessels to seal. This can be used for various medical purposes, such as stopping bleeding during surgery, destroying abnormal tissues (like tumors), or treating eye conditions like diabetic retinopathy and age-related macular degeneration.

It's important to note that this is a general definition, and the specific use of light coagulation may vary depending on the medical specialty and the individual patient's needs. As always, it's best to consult with a healthcare professional for more detailed information about any medical procedure or treatment.

'Erythrina' is a botanical term, not a medical one. It refers to a genus of plants in the family Fabaceae, also known as the pea or legume family. These plants are commonly called coral trees due to their bright red flowers. While some parts of certain species can have medicinal uses, such as anti-inflammatory and analgesic properties, 'Erythrina' itself is not a medical term or condition.

Blood viscosity is a measure of the thickness or flow resistance of blood. It is defined as the ratio of shear stress to shear rate within the flowing blood, which reflects the internal friction or resistance to flow. Blood viscosity is primarily determined by the concentration and size of red blood cells (hematocrit), plasma proteins, and other blood constituents. An increase in any of these components can raise blood viscosity, leading to impaired blood flow, reduced oxygen delivery to tissues, and potential cardiovascular complications if not managed appropriately.

Annexin A5 is a protein that belongs to the annexin family, which are calcium-dependent phospholipid-binding proteins. Annexin A5 has high affinity for phosphatidylserine, a type of phospholipid that is usually located on the inner leaflet of the plasma membrane in healthy cells. However, when cells undergo apoptosis (programmed cell death), phosphatidylserine is exposed on the outer leaflet of the plasma membrane.

Annexin A5 can bind to exposed phosphatidylserine on the surface of apoptotic cells and is commonly used as a marker for detecting apoptosis in various experimental settings, including flow cytometry, immunohistochemistry, and imaging techniques. Annexin A5-based assays are widely used in research and clinical settings to study the mechanisms of apoptosis and to develop diagnostic tools for various diseases, such as cancer, neurodegenerative disorders, and cardiovascular diseases.

Reference values, also known as reference ranges or reference intervals, are the set of values that are considered normal or typical for a particular population or group of people. These values are often used in laboratory tests to help interpret test results and determine whether a patient's value falls within the expected range.

The process of establishing reference values typically involves measuring a particular biomarker or parameter in a large, healthy population and then calculating the mean and standard deviation of the measurements. Based on these statistics, a range is established that includes a certain percentage of the population (often 95%) and excludes extreme outliers.

It's important to note that reference values can vary depending on factors such as age, sex, race, and other demographic characteristics. Therefore, it's essential to use reference values that are specific to the relevant population when interpreting laboratory test results. Additionally, reference values may change over time due to advances in measurement technology or changes in the population being studied.

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.

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

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

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

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

Aprotinin is a medication that belongs to a class of drugs called serine protease inhibitors. It works by inhibiting the activity of certain enzymes in the body that can cause tissue damage and bleeding. Aprotinin is used in medical procedures such as heart bypass surgery to reduce blood loss and the need for blood transfusions. It is administered intravenously and its use is typically stopped a few days after the surgical procedure.

Aprotinin was first approved for use in the United States in 1993, but its use has been restricted or withdrawn in many countries due to concerns about its safety. In 2006, a study found an increased risk of kidney damage and death associated with the use of aprotinin during heart bypass surgery, leading to its withdrawal from the market in Europe and Canada. However, it is still available for use in the United States under a restricted access program.

It's important to note that the use of aprotinin should be carefully considered and discussed with the healthcare provider, taking into account the potential benefits and risks of the medication.

Medical Definition:

"Risk factors" are any attribute, characteristic or exposure of an individual that increases the likelihood of developing a disease or injury. They can be divided into modifiable and non-modifiable risk factors. Modifiable risk factors are those that can be changed through lifestyle choices or medical treatment, while non-modifiable risk factors are inherent traits such as age, gender, or genetic predisposition. Examples of modifiable risk factors include smoking, alcohol consumption, physical inactivity, and unhealthy diet, while non-modifiable risk factors include age, sex, and family history. It is important to note that having a risk factor does not guarantee that a person will develop the disease, but rather indicates an increased susceptibility.

Lipids are a broad group of organic compounds that are insoluble in water but soluble in nonpolar organic solvents. They include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, and phospholipids. Lipids serve many important functions in the body, including energy storage, acting as structural components of cell membranes, and serving as signaling molecules. High levels of certain lipids, particularly cholesterol and triglycerides, in the blood are associated with an increased risk of cardiovascular disease.

Microfluidics is a multidisciplinary field that involves the study, manipulation, and control of fluids that are geometrically constrained to a small, typically sub-millimeter scale. It combines elements from physics, chemistry, biology, materials science, and engineering to design and fabricate microscale devices that can handle and analyze small volumes of fluids, often in the range of picoliters to microliters.

In medical contexts, microfluidics has numerous applications, including diagnostic testing, drug discovery, and personalized medicine. For example, microfluidic devices can be used to perform rapid and sensitive molecular assays for detecting pathogens or biomarkers in patient samples, as well as to screen drugs and evaluate their efficacy and toxicity in vitro.

Microfluidics also enables the development of organ-on-a-chip platforms that mimic the structure and function of human tissues and organs, allowing researchers to study disease mechanisms and test new therapies in a more physiologically relevant context than traditional cell culture models. Overall, microfluidics offers significant potential for improving healthcare outcomes by enabling faster, more accurate, and more cost-effective diagnostic and therapeutic strategies.

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.

A catalytic domain is a portion or region within a protein that contains the active site, where the chemical reactions necessary for the protein's function are carried out. This domain is responsible for the catalysis of biological reactions, hence the name "catalytic domain." The catalytic domain is often composed of specific amino acid residues that come together to form the active site, creating a unique three-dimensional structure that enables the protein to perform its specific function.

In enzymes, for example, the catalytic domain contains the residues that bind and convert substrates into products through chemical reactions. In receptors, the catalytic domain may be involved in signal transduction or other regulatory functions. Understanding the structure and function of catalytic domains is crucial to understanding the mechanisms of protein function and can provide valuable insights for drug design and therapeutic interventions.

Mannose-binding lectins (MBLs) are a group of proteins that belong to the collectin family and play a crucial role in the innate immune system. They are primarily produced by the liver and secreted into the bloodstream. MBLs have a specific affinity for mannose sugar residues found on the surface of various microorganisms, including bacteria, viruses, fungi, and parasites.

The primary function of MBLs is to recognize and bind to these mannose-rich structures, which triggers the complement system's activation through the lectin pathway. This process leads to the destruction of the microorganism by opsonization (coating the microbe to enhance phagocytosis) or direct lysis. MBLs also have the ability to neutralize certain viruses and inhibit the replication of others, further contributing to their antimicrobial activity.

Deficiencies in MBL levels or function have been associated with an increased susceptibility to infections, particularly in children and older adults. However, the clinical significance of MBL deficiency remains a subject of ongoing research.

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

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

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

I'm sorry for any confusion, but "Pentosan Sulfuric Polyester" is not a recognized medical term or a substance used in medicine. It seems to be a non-existent term. You might have made a mistake while typing or it could be a specific chemical compound not related to medical field. If you meant "Pentosan Polysulfate," I can provide its definition:

Pentosan Polysulfate is a semi-synthetic drug with properties similar to heparin. It is used in the treatment of osteoarthritis and interstitial cystitis due to its anti-inflammatory and analgesic effects. The chemical structure consists of a polyanionic, polydisperse molecule made up of repeating pentosan units linked by sulfuric ester bonds.

Gelatin is not strictly a medical term, but it is often used in medical contexts. Medically, gelatin is recognized as a protein-rich substance that is derived from collagen, which is found in the skin, bones, and connective tissue of animals. It is commonly used in the production of various medical and pharmaceutical products such as capsules, wound dressings, and drug delivery systems due to its biocompatibility and ability to form gels.

In a broader sense, gelatin is a translucent, colorless, flavorless food ingredient that is derived from collagen through a process called hydrolysis. It is widely used in the food industry as a gelling agent, thickener, stabilizer, and texturizer in various foods such as candies, desserts, marshmallows, and yogurts.

It's worth noting that while gelatin has many uses, it may not be suitable for vegetarians or those with dietary restrictions since it is derived from animal products.

Cysteine endopeptidases are a type of enzymes that cleave peptide bonds within proteins. They are also known as cysteine proteases or cysteine proteinases. These enzymes contain a catalytic triad consisting of three amino acids: cysteine, histidine, and aspartate. The thiol group (-SH) of the cysteine residue acts as a nucleophile and attacks the carbonyl carbon of the peptide bond, leading to its cleavage.

Cysteine endopeptidases play important roles in various biological processes, including protein degradation, cell signaling, and inflammation. They are involved in many physiological and pathological conditions, such as apoptosis, immune response, and cancer. Some examples of cysteine endopeptidases include cathepsins, caspases, and calpains.

It is important to note that these enzymes require a reducing environment to maintain the reduced state of their active site cysteine residue. Therefore, they are sensitive to oxidizing agents and inhibitors that target the thiol group. Understanding the structure and function of cysteine endopeptidases is crucial for developing therapeutic strategies that target these enzymes in various diseases.

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.

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

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

Prospective studies, also known as longitudinal studies, are a type of cohort study in which data is collected forward in time, following a group of individuals who share a common characteristic or exposure over a period of time. The researchers clearly define the study population and exposure of interest at the beginning of the study and follow up with the participants to determine the outcomes that develop over time. This type of study design allows for the investigation of causal relationships between exposures and outcomes, as well as the identification of risk factors and the estimation of disease incidence rates. Prospective studies are particularly useful in epidemiology and medical research when studying diseases with long latency periods or rare outcomes.

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.

Postoperative hemorrhage is a medical term that refers to bleeding that occurs after a surgical procedure. This condition can range from minor oozing to severe, life-threatening bleeding. Postoperative hemorrhage can occur soon after surgery or even several days later, as the surgical site begins to heal.

The causes of postoperative hemorrhage can vary, but some common factors include:

1. Inadequate hemostasis during surgery: This means that all bleeding was not properly controlled during the procedure, leading to bleeding after surgery.
2. Blood vessel injury: During surgery, blood vessels may be accidentally cut or damaged, causing bleeding after the procedure.
3. Coagulopathy: This is a condition in which the body has difficulty forming blood clots, increasing the risk of postoperative hemorrhage.
4. Use of anticoagulant medications: Medications that prevent blood clots can increase the risk of bleeding after surgery.
5. Infection: An infection at the surgical site can cause inflammation and bleeding.

Symptoms of postoperative hemorrhage may include swelling, pain, warmth, or discoloration around the surgical site, as well as signs of shock such as rapid heartbeat, low blood pressure, and confusion. Treatment for postoperative hemorrhage depends on the severity of the bleeding and may include medications to control bleeding, transfusions of blood products, or additional surgery to stop the bleeding.

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.

Point-of-care (POC) systems refer to medical diagnostic tests or tools that are performed at or near the site where a patient receives care, such as in a doctor's office, clinic, or hospital room. These systems provide rapid and convenient results, allowing healthcare professionals to make immediate decisions regarding diagnosis, treatment, and management of a patient's condition.

POC systems can include various types of diagnostic tests, such as:

1. Lateral flow assays (LFAs): These are paper-based devices that use capillary action to detect the presence or absence of a target analyte in a sample. Examples include pregnancy tests and rapid strep throat tests.
2. Portable analyzers: These are compact devices used for measuring various parameters, such as blood glucose levels, coagulation status, or electrolytes, using small volumes of samples.
3. Imaging systems: Handheld ultrasound machines and portable X-ray devices fall under this category, providing real-time imaging at the point of care.
4. Monitoring devices: These include continuous glucose monitors, pulse oximeters, and blood pressure cuffs that provide real-time data to help manage patient conditions.

POC systems offer several advantages, such as reduced turnaround time for test results, decreased need for sample transportation, and increased patient satisfaction due to faster decision-making and treatment initiation. However, it is essential to ensure the accuracy and reliability of these tests by following proper testing procedures and interpreting results correctly.

Bentonite is not a medical term, but a geological one. It refers to a type of clay that is composed primarily of montmorillonite, a soft phyllosilicate mineral. Bentonite has a wide range of uses, including as a binding agent in the manufacture of medicines, as an absorbent in cat litter and personal care products, and as a component in drilling muds and cement mixtures.

In medical contexts, bentonite is sometimes used as a bulk-forming laxative to treat constipation or irregularity. It works by absorbing water and increasing the size and weight of stool, which stimulates bowel movements. However, it's important to note that bentonite should only be used under the guidance of a healthcare professional, as it can interfere with the absorption of certain medications and may cause side effects such as bloating, gas, and diarrhea.

4-Hydroxycoumarins are a type of chemical compound that contains a hydroxy group (-OH) attached to the 4th carbon atom of the coumarin structure. Coumarins themselves are aromatic organic compounds, characterized by a benzene ring fused to a pyrone ring.

4-Hydroxycoumarins have gained attention in medical research due to their potential biological activities. For instance, some 4-hydroxycoumarins exhibit anticoagulant properties and are used as oral anticoagulant drugs, such as warfarin. These compounds work by inhibiting the vitamin K epoxide reductase enzyme, thereby interfering with the blood clotting process.

Additionally, 4-hydroxycoumarins have been investigated for their potential anticancer, anti-inflammatory, and antibacterial activities. However, more research is needed to fully understand their therapeutic potential and safety profiles.

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

Protamines are small, arginine-rich proteins that are found in the sperm cells of many organisms. They play a crucial role in the process of sperm maturation, also known as spermiogenesis. During this process, the DNA in the sperm cell is tightly packed and compacted by the protamines, which helps to protect the genetic material during its journey to fertilize an egg.

Protamines are typically composed of around 50-100 amino acids and have a high proportion of positively charged arginine residues, which allow them to interact strongly with the negatively charged DNA molecule. This interaction results in the formation of highly condensed chromatin structures that are resistant to enzymatic digestion and other forms of damage.

In addition to their role in sperm maturation, protamines have also been studied for their potential use in drug delivery and gene therapy applications. Their ability to bind strongly to DNA makes them attractive candidates for delivering drugs or genetic material directly to the nucleus of a cell. However, more research is needed to fully understand the potential benefits and risks associated with these applications.

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.

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.

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

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

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

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

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

Trypsin inhibitors are substances that inhibit the activity of trypsin, an enzyme that helps digest proteins in the small intestine. Trypsin inhibitors can be found in various foods such as soybeans, corn, and raw egg whites. In the case of soybeans, trypsin inhibitors are denatured and inactivated during cooking and processing.

In a medical context, trypsin inhibitors may be used therapeutically to regulate excessive trypsin activity in certain conditions such as pancreatitis, where there is inflammation of the pancreas leading to the release of activated digestive enzymes, including trypsin, into the pancreas and surrounding tissues. By inhibiting trypsin activity, these inhibitors can help reduce tissue damage and inflammation.

Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst, which remains unchanged at the end of the reaction. A catalyst lowers the activation energy required for the reaction to occur, thereby allowing the reaction to proceed more quickly and efficiently. This can be particularly important in biological systems, where enzymes act as catalysts to speed up metabolic reactions that are essential for life.

A homozygote is an individual who has inherited the same allele (version of a gene) from both parents and therefore possesses two identical copies of that allele at a specific genetic locus. This can result in either having two dominant alleles (homozygous dominant) or two recessive alleles (homozygous recessive). In contrast, a heterozygote has inherited different alleles from each parent for a particular gene.

The term "homozygote" is used in genetics to describe the genetic makeup of an individual at a specific locus on their chromosomes. Homozygosity can play a significant role in determining an individual's phenotype (observable traits), as having two identical alleles can strengthen the expression of certain characteristics compared to having just one dominant and one recessive allele.

Vitamin K2, also known as menaquinone, is a fat-soluble vitamin that plays a crucial role in the blood clotting process and bone metabolism. It is one of the two main forms of Vitamin K (the other being Vitamin K1 or phylloquinone), and it is found in animal-based foods and fermented foods.

Vitamin K2 is a collective name for a group of vitamin K compounds characterized by the presence of a long-chain fatty acid attached to the molecule. The most common forms of Vitamin K2 are MK-4 and MK-7, which differ in the length of their side chains.

Vitamin K2 is absorbed more efficiently than Vitamin K1 and has a longer half-life, which means it stays in the body for a longer period. It is stored in various tissues, including bones, where it plays an essential role in maintaining bone health by assisting in the regulation of calcium deposition and helping to prevent the calcification of blood vessels and other soft tissues.

Deficiency in Vitamin K2 is rare but can lead to bleeding disorders and weakened bones. Food sources of Vitamin K2 include animal-based foods such as liver, egg yolks, and fermented dairy products like cheese and natto (a Japanese food made from fermented soybeans). Some studies suggest that supplementing with Vitamin K2 may have benefits for bone health, heart health, and cognitive function. However, more research is needed to confirm these potential benefits.

Pregnancy is a physiological state or condition where a fertilized egg (zygote) successfully implants and grows in the uterus of a woman, leading to the development of an embryo and finally a fetus. This process typically spans approximately 40 weeks, divided into three trimesters, and culminates in childbirth. Throughout this period, numerous hormonal and physical changes occur to support the growing offspring, including uterine enlargement, breast development, and various maternal adaptations to ensure the fetus's optimal growth and well-being.

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

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

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.

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).

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.

Ion exchange chromatography is a type of chromatography technique used to separate and analyze charged molecules (ions) based on their ability to exchange bound ions in a solid resin or gel with ions of similar charge in the mobile phase. The stationary phase, often called an ion exchanger, contains fixed ated functional groups that can attract counter-ions of opposite charge from the sample mixture.

In this technique, the sample is loaded onto an ion exchange column containing the charged resin or gel. As the sample moves through the column, ions in the sample compete for binding sites on the stationary phase with ions already present in the column. The ions that bind most strongly to the stationary phase will elute (come off) slower than those that bind more weakly.

Ion exchange chromatography can be performed using either cation exchangers, which exchange positive ions (cations), or anion exchangers, which exchange negative ions (anions). The pH and ionic strength of the mobile phase can be adjusted to control the binding and elution of specific ions.

Ion exchange chromatography is widely used in various applications such as water treatment, protein purification, and chemical analysis.

Protein folding is the process by which a protein molecule naturally folds into its three-dimensional structure, following the synthesis of its amino acid chain. This complex process is determined by the sequence and properties of the amino acids, as well as various environmental factors such as temperature, pH, and the presence of molecular chaperones. The final folded conformation of a protein is crucial for its proper function, as it enables the formation of specific interactions between different parts of the molecule, which in turn define its biological activity. Protein misfolding can lead to various diseases, including neurodegenerative disorders such as Alzheimer's and Parkinson's disease.

An amino acid substitution is a type of mutation in which one amino acid in a protein is replaced by another. This occurs when there is a change in the DNA sequence that codes for a particular amino acid in a protein. The genetic code is redundant, meaning that most amino acids are encoded by more than one codon (a sequence of three nucleotides). As a result, a single base pair change in the DNA sequence may not necessarily lead to an amino acid substitution. However, if a change does occur, it can have a variety of effects on the protein's structure and function, depending on the nature of the substituted amino acids. Some substitutions may be harmless, while others may alter the protein's activity or stability, leading to disease.

Annexins are a family of calcium-dependent phospholipid-binding proteins that are found in various organisms, including humans. They are involved in several cellular processes, such as membrane organization, signal transduction, and regulation of ion channels. Some annexins also have roles in inflammation, blood coagulation, and apoptosis (programmed cell death).

Annexins have a conserved structure, consisting of a core domain that binds to calcium ions and a variable number of domains that bind to phospholipids. This allows annexins to interact with membranes in a calcium-dependent manner, which is important for their functions.

There are several different annexin proteins, each with its own specific functions and expression patterns. For example, annexin A1 is involved in the regulation of inflammation and has been studied as a potential target for anti-inflammatory therapies. Annexin A2 is involved in the regulation of coagulation and has been studied as a potential target for anticoagulant therapies. Other annexins have roles in cell division, differentiation, and survival.

Overall, annexins are important regulators of various cellular processes and have potential as targets for therapeutic intervention in a variety of diseases.

Hematocrit is a medical term that refers to the percentage of total blood volume that is made up of red blood cells. It is typically measured as part of a complete blood count (CBC) test. A high hematocrit may indicate conditions such as dehydration, polycythemia, or living at high altitudes, while a low hematocrit may be a sign of anemia, bleeding, or overhydration. It is important to note that hematocrit values can vary depending on factors such as age, gender, and pregnancy status.

A heterozygote is an individual who has inherited two different alleles (versions) of a particular gene, one from each parent. This means that the individual's genotype for that gene contains both a dominant and a recessive allele. The dominant allele will be expressed phenotypically (outwardly visible), while the recessive allele may or may not have any effect on the individual's observable traits, depending on the specific gene and its function. Heterozygotes are often represented as 'Aa', where 'A' is the dominant allele and 'a' is the recessive allele.

Colloids are a type of mixture that contains particles that are intermediate in size between those found in solutions and suspensions. These particles range in size from about 1 to 1000 nanometers in diameter, which is smaller than what can be seen with the naked eye, but larger than the molecules in a solution.

Colloids are created when one substance, called the dispersed phase, is dispersed in another substance, called the continuous phase. The dispersed phase can consist of particles such as proteins, emulsified fats, or finely divided solids, while the continuous phase is usually a liquid, but can also be a gas or a solid.

Colloids are important in many areas of medicine and biology, including drug delivery, diagnostic imaging, and tissue engineering. They are also found in nature, such as in milk, blood, and fog. The properties of colloids can be affected by factors such as pH, temperature, and the presence of other substances, which can influence their stability and behavior.

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

Ancylostoma is a genus of parasitic roundworms that are commonly known as hookworms. These intestinal parasites infect humans and other animals through contact with contaminated soil, often via the skin or mouth. Two species of Ancylostoma that commonly infect humans are Ancylostoma duodenale and Ancylostoma ceylanicum.

Ancylostoma duodenale is found primarily in tropical and subtropical regions, including parts of the Mediterranean, Africa, Asia, and southern Europe. It can cause a disease called ancylostomiasis or hookworm infection, which can lead to symptoms such as abdominal pain, diarrhea, anemia, and impaired growth in children.

Ancylostoma ceylanicum is found mainly in Southeast Asia, southern China, and some parts of Australia. It can also cause ancylostomiasis, with symptoms similar to those caused by Ancylostoma duodenale. However, Ancylostoma ceylanicum infections are often less severe than those caused by Ancylostoma duodenale.

Preventive measures for hookworm infection include wearing shoes in areas where the soil may be contaminated with feces, washing hands thoroughly after using the toilet or handling soil, and avoiding ingestion of contaminated soil or water. Treatment for hookworm infection typically involves administration of anthelmintic drugs to eliminate the parasites from the body.

High-performance liquid chromatography (HPLC) is a type of chromatography that separates and analyzes compounds based on their interactions with a stationary phase and a mobile phase under high pressure. The mobile phase, which can be a gas or liquid, carries the sample mixture through a column containing the stationary phase.

In HPLC, the mobile phase is a liquid, and it is pumped through the column at high pressures (up to several hundred atmospheres) to achieve faster separation times and better resolution than other types of liquid chromatography. The stationary phase can be a solid or a liquid supported on a solid, and it interacts differently with each component in the sample mixture, causing them to separate as they travel through the column.

HPLC is widely used in analytical chemistry, pharmaceuticals, biotechnology, and other fields to separate, identify, and quantify compounds present in complex mixtures. It can be used to analyze a wide range of substances, including drugs, hormones, vitamins, pigments, flavors, and pollutants. HPLC is also used in the preparation of pure samples for further study or use.

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.

Endothelial cells are the type of cells that line the inner surface of blood vessels, lymphatic vessels, and heart chambers. They play a crucial role in maintaining vascular homeostasis by controlling vasomotor tone, coagulation, platelet activation, and inflammation. Endothelial cells also regulate the transport of molecules between the blood and surrounding tissues, and contribute to the maintenance of the structural integrity of the vasculature. They are flat, elongated cells with a unique morphology that allows them to form a continuous, nonthrombogenic lining inside the vessels. Endothelial cells can be isolated from various tissues and cultured in vitro for research purposes.

Genetic therapy, also known as gene therapy, is a medical intervention that involves the use of genetic material, such as DNA or RNA, to treat or prevent diseases. It works by introducing functional genes into cells to replace missing or faulty ones caused by genetic disorders or mutations. The introduced gene is incorporated into the recipient's genome, allowing for the production of a therapeutic protein that can help manage the disease symptoms or even cure the condition.

There are several approaches to genetic therapy, including:

1. Replacing a faulty gene with a healthy one
2. Inactivating or "silencing" a dysfunctional gene causing a disease
3. Introducing a new gene into the body to help fight off a disease, such as cancer

Genetic therapy holds great promise for treating various genetic disorders, including cystic fibrosis, muscular dystrophy, hemophilia, and certain types of cancer. However, it is still an evolving field with many challenges, such as efficient gene delivery, potential immune responses, and ensuring the safety and long-term effectiveness of the therapy.

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

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

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

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

... may refer to: Coagulation factor IXa, an enzyme Coagulation factor XIa, an enzyme This ... disambiguation page lists articles associated with the title Activated blood coagulation factor XI. If an internal link led you ...
Coagulation factor XIII is the last zymogen to become activated in the blood coagulation cascade. Plasma factor XIII is a ... Coagulation factor XIII A chain is a protein that in humans is encoded by the F13A1 gene. This gene encodes the coagulation ... Hilgenfeld R, Liesum A, Storm R, Metzner HJ, Karges HE (1990). "Crystallization of blood coagulation factor XIII by an ... Takahashi N, Takahashi Y, Putnam FW (1986). "Primary structure of blood coagulation factor XIIIa (fibrinoligase, ...
"Blood-coagulation factor XIII". Drug Information Portal. U.S. National Library of Medicine. Portal: Medicine v t e (Webarchive ... congenital factor XIII A-subunit deficiency, which is a kind of Factor XIII deficiency. The medication prevents bleeding in ... Catridecacog, sold under the brand name Tretten in the US and NovoThirteen in the EU) is a class of recombinant factor XIII A- ... The Pharmacist February 01, 2014 Korte W (9 July 2014). "Catridecacog: a breakthrough in the treatment of congenital factor ...
"Blood-coagulation factor VIII, procoagulant". Drug Information Portal. U.S. National Library of Medicine. "Beroctocog alfa". ... a recombinant antihemophilic factor VIII Turoctocog alfa, a recombinant antihemophilic factor VIII "Coagulation Factor VIII, ... The cost of Factor VIII and similar clotting factors has been described as "highly expensive". The cost of the clotting factors ... Factor VIII is delivered by intravenous infusion. This transfer of a plasma byproduct into the blood stream of a hemophiliac ...
... participates in blood coagulation; it is a cofactor for factor IXa, which, in the presence of Ca2+ and ... The active protein (sometimes written as coagulation factor VIIIa) interacts with another coagulation factor called factor IX. ... Factor VIII (FVIII) is an essential blood-clotting protein, also known as anti-hemophilic factor (AHF). In humans, factor VIII ... "NIH: F8 - coagulation factor VIII". National Institutes of Health. "Entrez Gene: F8 coagulation factor VIII, procoagulant ...
"Hepatocytes express blood coagulation factor XII (Hageman factor)". The Journal of Laboratory and Clinical Medicine. 115 (4): ... Coagulation factor XII, also known as Hageman factor, is a plasma protein. It is the zymogen form of factor XIIa, an enzyme (EC ... "Characterization of human blood coagulation factor XII cDNA. Prediction of the primary structure of factor XII and the tertiary ... "Coagulation factor XII (Hageman factor) Washington D.C.: inactive factor XIIa results from Cys-571----Ser substitution". ...
"Recombinant Factor XIII". 2010. "Factor XIII". 2014-03-05. Muszbek, Laszlo; et al. (1999). "Blood coagulation factor XIII: ... Recombinant factor XIII (rFXIII) is the only drug alternative to receiving blood transfusions, the traditional treatment for ... Factor XIII Dorgalaleh A, Naderi M, Hosseini MS, Alizadeh S, Hosseini S, Tabibian S, et al. (2015). "Factor XIII Deficiency in ... "Safety and pharmacokinetics of recombinant factor XIII-A2 administration in patients with congenital factor XIII deficiency". ...
Examples are blood clots (coagulation factor XIII), skin, and hair. The catalytic reaction is generally viewed as being ... The exact biochemical activity of transglutaminases was discovered in blood coagulation protein factor XIII in 1968. Nine ... Deficiency of factor XIII (a rare genetic condition) predisposes to hemorrhage; concentrated enzyme can be used to correct the ... doi:10.1016/0003-9861(59)90413-8. Pisano JJ, Finlayson JS, Peyton MP (May 1968). "[Cross-link in fibrin polymerized by factor ...
Gailani D, Broze GJ (Aug 1991). "Factor XI activation in a revised model of blood coagulation". Science. 253 (5022): 909-12. ... In contrast to HMWK, LMWK is not involved in blood coagulation. Kininogen-1 is a constituent of the blood coagulation system as ... HMWK is essential for blood coagulation and assembly of the kallikrein-kinin system. Also, bradykinin, a peptide causing ... Williams-Fitzgerald-Flaujeac factor or the HMWK-kallikrein factor is a protein that in humans is encoded by the KNG1 gene. ...
"Activation of human blood coagulation factor XI independent of factor XII. Factor XI is activated by thrombin and factor XIa in ... "Coagulation factor XI: a database of mutations and polymorphisms associated with factor XI deficiency". Blood Coagulation & ... "Expression of human blood coagulation factor XI: characterization of the defect in factor XI type III deficiency". Blood. 79 (6 ... factor XII, factor XI, and factor IX). Factor XIa activates factor IX by selectively cleaving arg-ala and arg-val peptide bonds ...
These are important in protein-protein interactions with blood coagulation factors. Their name refers to the Kringle, a ... Patthy L (1985). "Evolution of the proteases of blood coagulation and fibrinolysis by assembly from modules". Cell. 41 (3): 657 ... and coagulation factor XII". J. Mol. Evol. 26 (4): 358-369. Bibcode:1987JMolE..26..358C. doi:10.1007/BF02101155. PMID 3131537. ... "Amino acid sequence of the heavy chain of human alpha-factor XIIa (activated Hageman factor)". J. Biol. Chem. 260 (9): 5328- ...
Type II domains have also been found in a range of proteins including blood coagulation factor XII; bovine seminal plasma ... Structural similarity of the protease precursor to blood coagulation factor XII". J. Biol. Chem. 268 (14): 10024-10028. doi: ... Fibronectins are involved in a number of important functions e.g., wound healing; cell adhesion; blood coagulation; cell ... Kornfeld S (1992). "Structure and function of the mannose 6-phosphate/insulinlike growth factor II receptors". Annu. Rev. ...
Kisiel W, Canfield WM (1981). Snake venom proteases that activate blood-coagulation factor V. Methods in Enzymology. Vol. 80 Pt ... Snake+venom+factor+V+activator at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Portal: Biology (CS1: ... Snake venom factor V activator (EC 3.4.21.95) is an enzyme. This enzyme catalyses the following chemical reaction Fully ... Tokunaga F, Nagasawa K, Tamura S, Miyata T, Iwanaga S, Kisiel W (November 1988). "The factor V-activating enzyme (RVV-V) from ...
Fresh normal plasma has all the blood coagulation factors with normal levels. Plasma from patients on oral anticoagulants ( ... Factor VII, Factor IX, and Factor X. Aged plasma is deficient in Factor V & Factor VIIIC. Serum is deficient in factors I, V & ... Mixing studies are tests performed on blood plasma of patients or test subjects to distinguish factor deficiencies from factor ... Factor deficient plasmas (Adsorbed Plasma & Aged Plasma, etc.) are used in mixing studies. Plasma with known factor ...
The best known function of tissue factor is its role in blood coagulation. The complex of TF with factor VIIa catalyzes the ... Tissue factor has been shown to interact with Factor VII. Tissue factor Blood plasma after the addition of tissue factor ... the interface between factor Xa and tissue factor in the quaternary complex tissue factor-factor VIIa-factor Xa-tissue factor ... Engelmann B (2007). "Initiation of coagulation by tissue factor carriers in blood". Blood Cells, Molecules & Diseases. 36 (2): ...
Leytus SP, Foster DC, Kurachi K, Davie EW (September 1986). "Gene for human factor X: a blood coagulation factor whose gene ... "Kcentra- prothrombin, coagulation factor vii human, coagulation factor ix human, coagulation factor x human, protein c, protein ... Factor X is activated, by hydrolysis, into factor Xa by both factor IX (with its cofactor, factor VIII in a complex known as ... The result is a Factor VIIa/TF complex, which catalyzes the activation of Factor X and Factor IX. Factor Xa formed on the ...
... of the blood coagulation-factor activity of FFP. Given the fact that there is typically an overabundance of coagulation factors ... Much of the donor blood supply is obtained at "remote" blood donation events, such as blood drives at colleges, community ... However, the (male) donor blood can be separated into packed red blood cells and plasma within 24 hours (and usually less).[ ... It differs from fresh-frozen plasma (FFP) in that it is frozen within 24 hours of blood collection, whereas FFP is frozen ...
Heikinheimo, R (1963). "Effect of filicin administered as an anthelmintic on the coagulation factors of the blood". Annales ...
doi:10.1182/blood-2002-01-0290. PMID 12393635. S2CID 8885302. Duga S, Asselta R, Tenchini ML (August 2004). "Coagulation factor ... Factor V (pronounced factor five) is a protein of the coagulation system, rarely referred to as proaccelerin or labile factor. ... All prothrombotic factor V mutations (factor V Leiden, factor V Cambridge, factor V Hong Kong) make it resistant to cleavage by ... Villoutreix BO, Dahlbäck B (June 1998). "Structural investigation of the A domains of human blood coagulation factor V by ...
May 1994). "Mutation in blood coagulation factor V associated with resistance to activated protein C". Nature. 369 (6475): 64-7 ... of human factor V (one of several substances that helps blood clot), which causes an increase in blood clotting ( ... "Factor V Leiden: The Copenhagen City Heart Study and 2 meta-analyses". Blood. 100 (1): 3-10. doi:10.1182/blood-2002-01-0111. ... The risk of developing a clot in a blood vessel depends on whether a person inherits one or two copies of the factor V Leiden ...
... is caused by abnormalities in blood consistency, which is determined by the levels of coagulation factors and ... The combination activates factor X to factor Xa and factor IX to factor IXa. Factor Xa (in the presence of factor V) activates ... Normal coagulation is initiated by the release of tissue factor from damaged tissue. Tissue factor binds to circulating factor ... and there are higher levels of coagulation proteins such as von Willebrand factor, fibrinogen, factor VII and factor VIII. ...
TAP and antistasin were used to estimate factor Xa as a drug target. Blood coagulation is a complex process by which the blood ... Heparin targets multiple factors in the blood coagulation cascade, one of them being FXa. At first, it had many side effects ... Factor Xa is an activated serine protease that occupies a key role in the blood coagulation pathway by converting prothrombin ... These factors activate each other in a blood coagulation cascade that occurs through two separate pathways that interact, the ...
This is a highly selective inhibitor of factor Xa in the blood coagulation pathways. TAP molecules are highly dipolar, and are ... a factor Xa inhibitor from the tick Ornithodoros moubata". FEBS Lett. 352 (2): 251-7. doi:10.1016/0014-5793(94)00941-4. PMID ... and tissue factor pathway inhibitor (TFPI). Kunitz STI protease inhibitor, the trypsin inhibitor initially studied by Moses ... tissue factor pathway inhibitor precursor; and Kunitz STI protease inhibitor contained in legume seeds. Kunitz domains are ...
... or blood-coagulation factor VIIa, activated blood coagulation factor VII), which in turn activates factor IX and factor X. ... the interface between factor Xa and tissue factor in the quaternary complex tissue factor-factor VIIa-factor Xa-tissue factor ... The main role of factor VII (FVII) is to initiate the process of coagulation in conjunction with tissue factor (TF/factor III ... The complex of factor VIIa with TF catalyzes the conversion of factor IX and factor X into the active proteases, factor IXa and ...
This also activates protein kinase C which stimulates platelet aggregation and therefore blood coagulation further down the ... Proteinase-activated receptor 1 (PAR1) also known as protease-activated receptor 1 or coagulation factor II (thrombin) receptor ... Blood. 89 (6): 1944-53. doi:10.1182/blood.V89.6.1944. PMID 9058715. Overview of all the structural information available in the ... Blood. 82 (5): 1532-7. doi:10.1182/blood.V82.5.1532.1532. PMID 8395910. "José RJ, Williams AE, Chambers RC (February 2014). " ...
... coagulation factor concentrates; and immunoglobulins. Blood products may also be called blood-based products to differ from ... A blood product is any therapeutic substance prepared from human blood. This includes whole blood; blood components; and plasma ... Whole blood is not commonly used in transfusion medicine. Blood components include: red blood cell concentrates or suspensions ... Cryoprecipitate Cryosupernatant Fresh frozen plasma PF24 Platelet transfusion Red blood cells The Clinical Use of Blood ...
The production of blood coagulation factors by the liver is disrupted, causing hemophiliac-like symptoms. Acute liver failure ... Again, synthetic function of the liver in terms of blood coagulation factors is impaired in addition to enlargement of the ... Patient responsiveness to nitisinone is assessed by measuring blood coagulation activity and SA levels in blood and urine. ... marked by the lack of formation of coagulation factors in blood. Patients are prone to infections at this stage accompanied by ...
"Blood coagulation factor IX residues Glu78 and Arg94 provide a link between both epidermal growth factor-like domains that is ... or trisaccharides may occur at a serine residue between the first two cysteines of blood coagulation factors VII and IX. Factor ... The cause of hemophilia B is decreased activity or deficiency of blood coagulation factor IX. Point mutations resulting in ... In the blood-clotting cascade, coagulation factors VII, IX and X and protein C contain a tandem of two cbEGF modules, whereas ...
"Lonomia obliqua Caterpillar Spicules Trigger Human Blood Coagulation via Activation of Factor X and Prothrombin". Thrombosis ... This anti-clotting agent would attach to another protein of the body's cells and cause them to leak as blood is unable to clot ... If blood products are required, they must be given cautiously to avoid fueling the constant consumptive coagulopathy. An ... Disseminated intravascular coagulation occurs as the toxin interacts with the victim's body. One serious effect on envenomed ...
... the blood coagulation factors II (prothrombin), VII, IX, and X, the anticoagulant proteins C and S, and the factor X-targeting ... involved in coagulation Factor VII (F7) - involved in coagulation Factor IX (F9) - involved in coagulation Factor X (F10) - ... Coagulation factor, Gla region InterPro: IPR002383 Thrombin (F2) (a.k.a. coagulation factor II; also its precursor prothrombin ... "Identification of the phospholipid binding site in the vitamin K-dependent blood coagulation protein factor IX". J. Biol. Chem ...
Activated blood coagulation factor XI may refer to: Coagulation factor IXa, an enzyme Coagulation factor XIa, an enzyme This ... disambiguation page lists articles associated with the title Activated blood coagulation factor XI. If an internal link led you ...
Comparison of blood coagulation factors between patients with gastrointestinal or intracranial bleeding under vitamin K ... The current guidelines recommend administering four-factor PCC (4 F-PCC) rather than FFP to reverse VKA-induced coagulopathy in ...
These proteins help your blood to clot after injury. Learn more. ... A coagulation factor test checks the function of certain ... Other names: blood clotting factors, factor assays, factor assay by number (Factor I, Factor II, Factor VIII, etc.) or by name ... What are Coagulation Factor Tests?. Coagulation factors are proteins in your blood. They help form blood clots to stop bleeding ... Coagulation factor tests are blood tests that check one or more of your clotting factors to see if you:. *Have too much or too ...
A low molecular weight platelet inhibitor of factor XIa: purification, characterization, and possible role in blood coagulation ... The inhibition by PIXI of factor XIa-catalyzed activation of factor IX and its capacity to prevent factor XIa inactivation by ... combined with the specificity of PIXI for factor XIa among serine proteases found in blood, suggest a role for PIXI in the ... factor XIIa, plasma kallikrein, plasmin, and activated protein C and did not inhibit factor Xa, thrombin, tPA, or trypsin, ...
Tissue factor (TF) is the primary initiator of blood coagulation in vivo and the only blood coagulation factor for which a ... TF is the primary initiator of blood coagulation in vivo and the only major blood coagulation factor in which a human genetic ... TF is the primary initiator of blood coagulation in humans (14) and remains the only blood coagulation factor for which a human ... The crystal structure of the complex of blood coagulation factor VIIa with soluble tissue factor. Nature. 1996;380(6569):41-46. ...
The blood coagulating factors are proteins or enzymes that prevent the bleeding. ... Europe Blood Coagulation Factor Market Report, By Product Type (Blood Product, Non-Plasma Derived Coagulation Factor), End User ... Blood Coagulation Factor Market- Segmental Overview. The Europe blood coagulation factor market is segmented by product type, ... Europe Blood Coagulation Factor Market by Country. Blood coagulation factor market is studied for the following countries ...
Thrombophilias are hereditary and/or acquired pathologies that predispose individuals to suffering thrombosis or blood clots. ...
Human Coagulation Factor XIV / Protein C protein (4998-SE) is manufactured by R&D Systems, over 95% purity. Reproducible ... Anticoagulant protein C; APC; Autoprothrombin IIA; Blood coagulation factor XIV; Coagulation Factor XIV; EC 3.4.21; EC 3.4. ... Home / Coagulation Factor XIV/Protein C / Recombinant Human Active Coagulation Factor XIV/ProteinC, CF ... Background: Coagulation Factor XIV/Protein C. Protein C (PROC) is a vitamin K-dependent serine protease synthesized in liver as ...
This gene encodes coagulation factor XI of the blood coagulation cascade. This protein is present in plasma as a zymogen, which ... This activated plasma factor XI triggers the middle phase of the intrisic pathway of blood coagulation by activating factor IX ... Coagulation Factor XI / FXI / F11 Antibody, Rabbit PAb * Coagulation Factor XI / FXI / F11 Antibody, Rabbit PAb, Antigen ... F11 coagulation factor XI [Homo sapiens] F11 coagulation factor XI [Homo sapiens]. Gene ID:2160 ...
Blood Coagulation Factor IV. Coagulation Factor IV. Factor IV. Factor IV, Coagulation. ... It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in ...
Myocardial fibrosis in mice with overexpression of human blood coagulation factor IX. In: Blood. 2003 ; Vol. 101, No. 5. pp. ... N2 - Elevated circulatory levels of many blood coagulation factors are known to be a risk factor for deep vein thrombosis in ... AB - Elevated circulatory levels of many blood coagulation factors are known to be a risk factor for deep vein thrombosis in ... Elevated circulatory levels of many blood coagulation factors are known to be a risk factor for deep vein thrombosis in humans ...
... is characterized by systemic activation of blood coagulation, which results in generation and deposition of fibrin, leading to ... Consumption and subsequent exhaustion of coagulation proteins and pl... ... it is liver disease with reduced blood coagulation factor synthesis and reduced clearance of activate products of coagulation. ... it is liver disease with reduced blood coagulation factor synthesis and reduced clearance of activate products of coagulation. ...
have been told that you have inhibitors to von Willebrand factor. *have been told that you have inhibitors to blood coagulation ... Your doctor will perform blood tests to check your von Willebrand factor activity and the presence of any inhibitors. If high ... Blood Clots. Vonvendi may increase your risk of developing a blood clot, which could lead to pulmonary embolism (a clot in your ... Your first dose of Vonvendi for each bleeding episode may be given with a recombinant factor VIII (factor VIII not produced ...
It belongs to a group of drugs called blood coagulation factors. These drugs work to activate substances in your blood to form ... You may need blood tests done after using Coagadex to be sure that your blood level of Factor X is high enough to clot your ... Many people with coagulation factor deficiencies learn to infuse their treatment by themselves or with the help of a family ... Factor X deficiency is an inherited bleeding disorder that prevents blood from clotting normally. Coagadex is used to treat and ...
Idelvion belongs to a group of drugs called blood coagulation factors. These work to activate substances in your blood to form ... You may need to have blood tests done after getting Idelvion to be sure that your blood level of Factor IX is high enough to ... Coagulation Factor IX (Recombinant), Albumin Fusion Protein. For more information on this medication choose from the list of ... FDA approves first coagulation factor-albumin fusion protein to treat patients with hemophilia B. FDA. 2016 Idelvion. [Package ...
In massive blood loss, PCCs are administered to rapidly restore vitamin K-dependent coagulation factors. The recommended dose ... Currently, the use of activated coagulation factors in surgical bleeding is an off-label indication. The coagulation factor ... recombinant or activated coagulation factors can play an important role. Several recombinant coagulation factors are ... This scenario illustrates a common dilemma in blood transfusion: Whenever coagulation factors are transfused, fluid is also ...
Surface-induced activation of factor XII is critical part of the intrinsic pathway of blood coagulation. The mechanism of this ... Mathematical model of the mechanism and kinetics of blood coagulation factor XII. ... an active form of factor XII, are produced purely by factor XII contacting a surface or if traces of factor XIIa pre-exist. ... it is not known whether factor XII first has to bind to a surface before it can interact with the surface-bound factor XIIa in ...
Although acquired factor XIII deficiency has been described in association with hepatic failure, inflammatory bowel disease, ... Congenital factor XIII (FXIII) deficiency, originally recognized by Duckert in 1960, is a rare autosomal recessive disease ... is mediated by blood clotting factors. Clotting factors function as cofactors in the blood-coagulation cascade. ... Injury to the blood vessel wall and factors released by platelets initiate the coagulation cascade. Formation of an insoluble ...
Deletion of the blood coagulation factor fibrinogen largely reversed blood-induced microglia neurodegenerative signatures. ... However, how blood proteins polarize innate immune cells remains largely unknown. Here, we established an unbiased blood-innate ... Our data provide an interactive resource for investigation of the immunology of blood proteins that could support therapeutic ... Blood induced widespread microglial transcriptional changes, including changes involving oxidative stress and neurodegenerative ...
Categories: Blood Coagulation Factors Image Types: Photo, Illustrations, Video, Color, Black&White, PublicDomain, ...
The platelets arise from the fragmentation of the cytoplasm of megakaryocytes in the bone marrow and circulate in blood as disc ... and the endothelial cells lining the blood vessels. ... coagulation factors, and the endothelial cells lining the blood ... The levels of coagulation factor VIII are also low, due to the decrease in vWf, the carrier of factor VIII in plasma. ... in which the factor VIII activity level is low because of a defect in factor VIII itself, in von Willebrand disease the factor ...
No new DDDs will be established in B02BD Blood coagulation factors. 3) Refers to ampicillin. 4) The DDD for tiotropium bromide ... 2) DDDs for the various blood coagulation factors in all ATC 5th level codes in B02BD are deleted. ...
Studies on Blood Coagulation Factors in a Case of Liver Cirrhosis *STIG-ARNE JOHANSSON ... Blood Platelets - their Relationship to the Blood Clotting System and to Hemostasis: A Review ... Studies on Bank Blood Collected and Stored under Various Conditions with Particular Reference to Its Use in Open Heart Surgery ... The Effect of Stored Blood Transfusions on the Platelet Levels in Patients Undergoing Surgical Procedures. Acta Haematol (1957 ...
... factor XII, high-molecular-weight kininogen (HK), and prekallikrein (PK). Factor XI is synthesized in the liver and ... The so-called contact factors include factor XI, ... Factor XI activation in a revised model of blood coagulation. ... Activation of human blood coagulation factor XI independent of factor XII. Factor XI is activated by thrombin and factor XIa in ... Comparison of bleeding tendency, factor XI coagulant activity, and factor XI antigen in 25 factor XI-deficient kindreds. Blood ...
Blood coagulation factor XII drives adaptive immunity during neuroinflammation via CD87-mediated modulation of dendritic cells ... Blood, 9.775, 121, 679-691.. Meuth, S. G., Budde, T., Kanyshkova, T., Broicher, T., Munsch, T. & Pape, H. C. 2003. Contribution ...
Upon intravenous delivery however, many adenoviruses become coated in the blood coagulation protein Factor X (FX). Coated ...
The defective protein (coagulation factor VIII) is required for normal blood clotting. Affected individuals require injections ... This cholesterol is transported in the blood by a lipoprotein called LDL. When LDL cant get into cells, it increases to high ... The normal function of the protein is to inhibit enzymes which escape from white blood cells in the process of destroying ... Since the amount of phosphate in the blood is much lower than normal, the bones are chronically stimulated to release calcium ...
Tissue factor, blood coagulation, and beyond: an overview. Int J Inflam. 2011;2011:. 367284. .PubMedGoogle Scholar ... and for tissue factor we used Human Coagulation Factor III/Tissue Factor Quantikine ELISA Kit (R&D Systems). ... Circulating hepatocyte growth factor as an independent prognostic factor of disseminated intravascular coagulation. Thromb Res ... Tissue factor as an initiator of coagulation and inflammation in the lung. Crit Care. 2008;12(Suppl 6):S3.PubMedGoogle Scholar ...
View our 3 Coagulation Factor X Proteins and Enzymes for your research. ... Coagulation Factor X: Products. Coagulation Factor X is a vitamin K-dependent plasma protease that activates thrombin in blood ... coagulation. Initially synthesized in the liver as a single-chain precursor, factor X is activated by both the intrinsic and ...
Helical Organization of Blood Coagulation Factor VIII on Lipid Nanotubes Journal (Bioengineering). Synthesis of an Intein- ...
  • Elevated circulatory levels of many blood coagulation factors are known to be a risk factor for deep vein thrombosis in humans. (elsevierpure.com)
  • Here we report the first direct demonstration of a close association between elevated circulatory factor IX levels in mice with thrombosis as well as myocardial fibrosis. (elsevierpure.com)
  • These observations support the hypothesis that persistently high circulatory levels of factor IX are a risk factor not only for thrombosis and/or thromboembolism, but also for myocardial fibrosis mimicking human myocardial infarction. (elsevierpure.com)
  • The subcommittee on DIC of the International Society on Thrombosis and Haemostasis has suggested the following definition for DIC: "An acquired syndrome characterized by the intravascular activation of coagulation with loss of localization arising from different causes. (medscape.com)
  • Under physiological circumstances, the resistance of the endothelial cell lining to interactions with platelets and coagulation factors prevents thrombosis. (medscape.com)
  • [ 7 ] In a mouse model, factor XI appears to play a greater role in thrombosis than in hemostasis. (medscape.com)
  • On the other hand, a study by Georgi et al indicated that in persons genetically disposed to lower concentrations of factor XI, the risk of venous thrombosis and ischemic stroke are reduced. (medscape.com)
  • Employing data related to genetic variants that alter factor XI levels, the investigators found that in these individuals, the odds ratios (ORs) for venous thrombosis and ischemic stroke were 0.1 and 0.47, respectively, with the OR for major bleeding being 0.7. (medscape.com)
  • Moreover, the results indicated that among patients with lower factor XI levels, the absolute risk reductions are greater in individuals at high risk for thrombosis, including those with atrial fibrillation or cancer. (medscape.com)
  • The authors suggested that the risk of venous thrombosis and ischemic stroke may be significantly reduced by pharmacologic inhibition of factor XI, with no clear evidence demonstrating that this therapy would increase the risk for major bleeding. (medscape.com)
  • Warfarin is used to prevent blood clots and is usually administered to patients who have had a heart attack, heart valve surgery, stroke, deep vein thrombosis/pulmonary embolism, or have irregular heartbeat. (pharmacytimes.com)
  • Biotest unveiled functional data from its new Factor VIII compounds at the ISTH 2020 congress (International Society on Thrombosis and Haemostasis). (pharmiweb.com)
  • A collaborative study conducted by the Division of Hemostasis and Thrombosis at Beth Israel Deaconess Medical Center (BIDMC) and the Wyss Institute at Harvard University suggests that parmodulins may provide anti-inflammatory and anti-thrombotic protection to endothelial cells, without interfering with blood clotting. (news-medical.net)
  • Disorders of coagulation are disease states which can result in bleeding ( hemorrhage or bruising ) or obstructive clotting ( thrombosis ). (wn.com)
  • Human blood coagulation, haemostasis and thrombosis / edited by Rosemary Biggs. (who.int)
  • ABSTRACT This study determined the prevalence of inherited factor V Leiden mutation in a group of 128 thrombosis patients (102 with venous thrombosis and 26 with arterial thrombosis) attending a hospital in Sousse, Tunisia, and a control group of 100 with no history of thrombosis. (who.int)
  • Screening Tunisian patients with venous thrombosis and their relatives for factor V Leiden may be justified. (who.int)
  • When you have an injury that causes bleeding, blood cells called platelets begin to make a soft blood clot to stop the bleeding. (medlineplus.gov)
  • The platelets release molecules into your blood that begin to turn on the clotting factors. (medlineplus.gov)
  • A low molecular weight platelet inhibitor of factor XIa (PIXI) has been purified 250-fold from releasates of washed and stimulated human platelets. (qxmd.com)
  • Immunoblot analysis showed that PIXI is not the inhibitory domain of protease nexin II, a potent inhibitor of factor XIa also secreted from platelets. (qxmd.com)
  • Injury to the blood vessel wall and factors released by platelets initiate the coagulation cascade. (medscape.com)
  • The hemostatic system consists of platelets, coagulation factors, and the endothelial cells lining the blood vessels. (medscape.com)
  • The platelets arise from the fragmentation of the cytoplasm of megakaryocytes in the bone marrow and circulate in blood as disc-shaped anucleate particles for 7-10 days. (medscape.com)
  • Platelets play a primary role in this process, interacting with subendothelium-bound von Willebrand factor (vWf) via the membrane glycoprotein (GP) Ib complex. (medscape.com)
  • Binding of factor XIa to activated platelets localizes it to the site of clot formation and protects it from plasma protease inhibitors. (medscape.com)
  • PAR1 makes mechanistic analysis difficult as it is present on both endothelial cells that line blood vessels as well as on platelets that circulate through the blood and promote clotting. (news-medical.net)
  • The mechanism of coagulation involves activation, adhesion, and aggregation of platelets along with deposition and maturation of fibrin . (wn.com)
  • Exposure of blood to the space under the endothelium initiates two processes: changes in platelets, and the exposure of subendothilial tissue factor to plasma Factor VII , which ultimately leads to fibrin formation. (wn.com)
  • Blood-borne transmission of pathogens has highlighted the crucial importance of effective policies, strategies, quality systems, and legislative and regulatory frameworks in the collection, testing, processing and supply of blood components, such as red cells, platelets and plasma, for clinical use. (who.int)
  • [ 1 ] Consumption and subsequent exhaustion of coagulation proteins and platelets (from ongoing activation of coagulation) may induce severe bleeding, though microclot formation may occur in the absence of severe clotting factor depletion and bleeding. (medscape.com)
  • [ 1 ] Protease nexin 2, a tightly binding Kunitz-type factor XIa inhibitor, is also present in platelets. (medscape.com)
  • Deficiency of the blood coagulation factors causes the haemophilia and von Willebrand disease. (axiommrc.com)
  • Impact of genetic structural variants in factor XI deficiency: identification, accurate characterization, and inferred mechanism by long-read sequencing. (nih.gov)
  • Phenotype and genotype analysis of patients with severe factor XI deficiency in Shaanxi Province, China. (nih.gov)
  • Coagadex helps stop or prevent bleeding in those with hereditary Factor X deficiency. (rxwiki.com)
  • Coagadex is a prescription medication used to replace the clotting factor that is missing in people with Factor X deficiency. (rxwiki.com)
  • Factor X deficiency is an inherited bleeding disorder that prevents blood from clotting normally. (rxwiki.com)
  • Coagadex is used to treat and control bleeding in patients aged 12 years and over with hereditary Factor X deficiency. (rxwiki.com)
  • Coagadex is a prescription medication control bleeding and prevent bleeding in adults and children (aged 12 years and above) with hereditary Factor X deficiency, an inherited bleeding disorder. (rxwiki.com)
  • Idelvion is a prescription medication used to treat children and adults with Hemophilia B. This medication replaces the clotting factor ( factor IX ) that is missing in people with hemophilia B. Hemophilia B is also called congenital factor IX deficiency or Christmas disease. (rxwiki.com)
  • For patients with congenital factor XIII A-subunit deficiency, which includes the majority of patients, treatment with recombinant factor XIII, as well as treatment with factor XIII concentrate, can be considered. (medscape.com)
  • Indicated for routine prophylactic treatment of congenital factor XIII (FXIII) deficiency. (medscape.com)
  • Mangla A, Hamad H, Kumar A. Factor XIII Deficiency. (medscape.com)
  • Delayed umbilical bleeding--a presenting feature for factor XIII deficiency: clinical features, genetics, and management. (medscape.com)
  • Karimi M, Peyvandi F, Naderi M, Shapiro A. Factor XIII deficiency diagnosis: challenges and tools. (medscape.com)
  • Central nervous system bleeding in pediatric patients with factor XIII deficiency: a study on 23 new cases. (medscape.com)
  • Inbal A, Oldenburg J, Carcao M, Rosholm A, Tehranchi R, Nugent D. Recombinant factor XIII: a safe and novel treatment for congenital factor XIII deficiency. (medscape.com)
  • New developments in the management of congenital Factor XIII deficiency. (medscape.com)
  • Gynecological and obstetric outcome in the French cohort of women with factor XIII deficiency. (medscape.com)
  • Deficiency of factor XI is a congenital condition that is inherited in an autosomal-recessive fashion. (medscape.com)
  • Octapharma USA) for the urgent reversal of acquired coagulation factor deficiency in adults who need an urgent surgery or invasive procedure and are currently taking a vitamin K antagonist (warfarin), according to a press release. (pharmacytimes.com)
  • However, warfarin can lead to deficiency of vitamin K-dependent coagulation factors (Factor II (prothrombin), Factor VII, Factor IX and Factor X, and antithrombotic Proteins C and S), which can cause excess bleeding. (pharmacytimes.com)
  • Haemophilia A is caused by a deficiency of clotting factor VIII. (pharmiweb.com)
  • 1 It is caused by a deficiency or defective function of VWF, one of several types of proteins in the blood that are needed for proper blood clotting. (hemophiliafed.org)
  • 1 Â Due to this defective function or deficiency, blood is not able to clot effectively in people with VWD. (hemophiliafed.org)
  • Factor XI is warranted when a deficiency of factor XI is suspected. (medscape.com)
  • also known as Hageman factor deficiency. (lu.se)
  • An amount of PIXI which inhibited by 50% factor XIa cleavage of the chromogenic substrate S2366 (Pyr-Glu-Pro-Arg-pNA-2H2O) only slightly inhibited (5-9%) factor XIIa, plasma kallikrein, plasmin, and activated protein C and did not inhibit factor Xa, thrombin, tPA, or trypsin, suggesting specificity for factor XIa. (qxmd.com)
  • This protein is present in plasma as a zymogen, which is a unique plasma coagulation enzyme because it exists as a homodimer consisting of two identical polypeptide chains linked by disulfide bonds. (nih.gov)
  • The unknown functions of a known protein: the case of coagulation factor XI. (nih.gov)
  • These work by providing a protein that is needed for the blood to clot. (rxwiki.com)
  • Nephrotic syndrome is a group of symptoms that include protein in the urine, low blood protein levels, high cholesterol levels, high triglyceride levels, and swelling. (rxwiki.com)
  • Blood protein extravasation through a disrupted blood-brain barrier and innate immune activation are hallmarks of neurological diseases and emerging therapeutic targets. (nature.com)
  • Upon intravenous delivery however, many adenoviruses become coated in the blood coagulation protein Factor X (FX). (gla.ac.uk)
  • P-selectin, soluble endothelial protein C receptor, soluble thrombomodulin, plasminogen activator inhibitor 1, ADAMTS-13, von Willebrand factor, tissue factor, soluble intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 were more elevated in LF patients than in controls. (cdc.gov)
  • Endothelial protein C receptor, thrombomodulin, intercellular adhesion molecule 1, plasminogen activator inhibitor 1, D-dimer, and hepatocyte growth factor were higher in fatal than nonfatal LF cases. (cdc.gov)
  • This gene encodes a member of von Willebrand factor A domain-containing protein family. (nih.gov)
  • Activated protein C (APC) is a natural anticoagulant protein used for treating severe blood infections and wounds. (news-medical.net)
  • in all mammals , coagulation involves both a cellular (platelet) and a protein (coagulation factor) component. (wn.com)
  • However, many disease-predisposing factors and/or contributing factors have been identified, including inflammation, endothelial cell dysfunction, aberrant vascular wall cell proliferation and mutations in the bone morphogenetic protein-receptor type 2 ( Bmpr2 ) gene [ 1 - 3 ]. (ersjournals.com)
  • The Tregitope technology is an additional immune-modulating tool that is expected to improve tolerance of protein drugs such as replacement enzymes, blood factors, and monoclonal antibodies. (epivax.com)
  • These interactions may stabilize the vertex region of the capsid and prevent release of the virally encoded membrane lytic factor, protein VI, which is packaged inside of the viral capsid, thus effectively neutralizing the virus. (bvsalud.org)
  • CAMBRIDGE, Massachusetts, January 31, 2022 - Takeda Pharmaceutical Company Limited ("Takeda") today announced that the U.S. Food & Drug Administration (FDA) approved VONVENDI ® [von Willebrand factor (Recombinant)] for routine prophylaxis to reduce the frequency of bleeding episodes in patients with severe Type 3 von Willebrand disease (VWD) receiving on-demand therapy. (hemophiliafed.org)
  • The clotting factors work together in a chain reaction to form a harder blood clot that will stay firmly in place. (medlineplus.gov)
  • Your blood doesn't clot enough after an injury or surgery. (medlineplus.gov)
  • An abnormal result on a blood test that checks how long it takes your blood to clot. (medlineplus.gov)
  • Mechanism for the blood clot is haemostasis which is controlled by the several factors such as the blood clotting factors. (axiommrc.com)
  • Vonvendi may increase your risk of developing a blood clot, which could lead to pulmonary embolism (a clot in your lungs), stroke, or heart attack. (rxwiki.com)
  • Formation of an insoluble fibrin clot, which reinforces the initial platelet plug, is mediated by blood clotting factors. (medscape.com)
  • Promotes cross-linking of fibrin during coagulation and is essential to the physiological protection of the clot against fibrinolysis. (medscape.com)
  • This negative surface provides binding sites for enzymes and cofactors of the coagulation system, resulting in the formation of a clot (secondary hemostasis). (medscape.com)
  • Coagulation (also known as clotting ) is the process by which blood changes from a liquid to a gel, forming a clot . (wn.com)
  • We subsequently discuss how β-TCP can regulate osteogenic processes to aid bone repair/healing, namely osteogenic differentiation of mesenchymal stem cells, formation of blood vessels, release of angiogenic growth factors, and blood clot formation. (frontiersin.org)
  • A closer examination revealed that pulmonary embolism were by far the most common form of blood clot and were found to exist in one third of the patients examined with imaging tests. (usz.ch)
  • They help form blood clots to stop bleeding when you have an injury. (medlineplus.gov)
  • You have several different types of clotting factors that are all important for making blood clots. (medlineplus.gov)
  • But normally, clotting factors are turned off, so you don't form abnormal blood clots. (medlineplus.gov)
  • Your blood clots too easily, even without an injury. (medlineplus.gov)
  • This condition may lead to clots that block your blood flow and cause serious conditions, such as heart attack , stroke , or clots in the lungs . (medlineplus.gov)
  • Coagulation factor tests are also used to monitor people who have a known problem with clotting factors or who take medicine called blood thinners to lower the risk of blood clots. (medlineplus.gov)
  • In addition to checking for neutralizing antibodies, your doctor will also check your von Willebrand factor levels to make sure they are not too high, which could increase your risk of blood clots. (rxwiki.com)
  • These drugs work to activate substances in your blood to form clots and decrease bleeding episodes. (rxwiki.com)
  • Hyperfibrinolysis destroys stable blood clots, and antifibrinolytic agents may be required. (medscape.com)
  • Arixtra (fondaparinux) is an inhibitor of the blood clotting Factor X and is used to prevent blood clots , often in people undergoing certain surgical procedures. (rxlist.com)
  • Although inflammatory responses are critical for engaging the immune system to overcome disease and injury, they can also lead to a rise in the production of thrombin, which may in turn cause harmful blood clots and other conditions. (news-medical.net)
  • COVID-19 causes a noticeably sharp increase in blood coagulation factors resulting in blood clots. (usz.ch)
  • In cumulative terms, 21% of them were found to have blood clots, half of which were diagnosed within the first 24 hours after being admitted to the hospital. (usz.ch)
  • It must therefore be assumed that many patients had already developed these blood clots before going to the hospital. (usz.ch)
  • Severe pulmonary embolism, i.e. pulmonary vessels blocked by blood clots, can quickly lead to death due to heart failure if left untreated. (usz.ch)
  • In view of the many blood clots diagnosed in the Milan study within 24 hours and given the small sample of persons examined, a considerably larger number of people must therefore be expected to sustain severe pulmonary embolism as a result of COVID-19 as most COVID-19 patients remain in home quarantine during their illness. (usz.ch)
  • Your body can make neutralizing antibodies which inhibit von Willebrand factor and/or factor VIII from working correctly. (rxwiki.com)
  • HAT and HAT RI address the three major challenges of current Factor VIII products for haemophilia A therapy, which are the short Factor VIII half-life, the intravenous application route and the high risk for inhibitor development. (pharmiweb.com)
  • Results from further animal models support a 4-fold extension of the half-life in blood circulation while maintaining the wild-type characteristics of activated Factor VIII with full in vivo functionality. (pharmiweb.com)
  • HAT and HAT RI (Haemophilia A Therapeutic and Haemophilia A Therapeutic Reduced Immunogenicity) are in preclinical development for the treatment of haemophilia A. HAT and HAT RI are characterized by a substantial half-life extension of Factor VIII and the potential for intravenous and subcutaneous administration. (pharmiweb.com)
  • These benefits are based on the fusion of special Factor VIII sequences with four albumin-binding peptides shielding the active substance from degradation. (pharmiweb.com)
  • HAT RI additionally provides modifications within the Factor VIII section to further reduce the risk of inhibitor development, one of the major issues in haemophilia A therapy. (pharmiweb.com)
  • Up to 30% of patients with severe haemophilia develop antibodies (inhibitors) against the therapeutic factor VIII. (pharmiweb.com)
  • Your first dose of VONVENDI for each bleeding episode may be administered with a recombinant factor VIII as instructed by your healthcare provider. (hemophiliafed.org)
  • Your healthcare provider will instruct you whether additional doses of VONVENDI with or without recombinant factor VIII are needed. (hemophiliafed.org)
  • With this collaboration a novel, non-immunogenic Factor VIII (FVIII) should be developed. (epivax.com)
  • The coagulation factor VIII used for Hemophilia therapy will be altered in such a way that the immune system of the patients may not respond by developing inhibitory antibodies. (epivax.com)
  • The formation of inhibitory antibodies against the Coagulation factor VIII reduces its efficacy and may lead to severe bleeding disorders. (epivax.com)
  • A tolerized and de-immunized version of factor VIII would allow patients and their families to experience the benefits of FVIII treatment, which does not induce a reaction of the immune system (no immunogenicity) without the fear of developing inhibitory antibodies ("inhibitors") against the therapeutic factor VIII. (epivax.com)
  • This is an entirely novel approach to improving factor VIII therapy. (epivax.com)
  • In the current collaboration, EpiVax and Biotest scientists will use Tregitopes to selectively dampening unwanted immune responses to factor VIII, the primary therapeutic used to control bleeding for individuals who have hemophilia A. For more information about Tregitopes visit https://www.epivax.com/pipeline/immune-modulation/ . (epivax.com)
  • Platelet disorders lead to defects in primary hemostasis and produce signs and symptoms different from coagulation factor deficiencies (disorders of secondary hemostasis). (medscape.com)
  • [ 10 ] which, though significant, are not as severe as those seen in hemophilia A or hemophilia B . This finding reflects the important role factor XI plays in hemostasis. (medscape.com)
  • It potentially results in hemostasis , the cessation of blood loss from a damaged vessel, followed by repair. (wn.com)
  • Secondary hemostasis occurs simultaneously: Additional coagulation factors or clotting factors beyond Factor VII ( listed below ) respond in a complex cascade to form fibrin strands, which strengthen the platelet plug. (wn.com)
  • Monroe DM HM, Roberts HR. Molecular Biology and Biochemistry of the Coagulation Factors and Pathways of Hemostasis. (medscape.com)
  • Therefore, depending on the relative amounts of Factor XIa and Factor VIIa generated in vivo and other factors which may influence reaction rates, these kinetic parameters provide part of the information required for assessing the relative contributions of the intrinsic and extrinsic pathways to Factor IX activation, and suggest that the Factor XIa catalyzed reaction is physiologically significant. (jci.org)
  • Initially synthesized in the liver as a single-chain precursor, factor X is activated by both the intrinsic and extrinsic pathways to Xa, which consists of disulfide bond-linked light and heavy chains. (rndsystems.com)
  • Patients with PH exhibited higher circulating levels of microparticles compared to control subjects and in vitro or in vivo generated microparticles can induce endothelial dysfunction, interfere with coagulation pathways or modulate inflammatory phenomenon. (ersjournals.com)
  • Disseminated intravascular coagulation (DIC) is characterized by systemic activation of blood coagulation, which results in generation and deposition of fibrin, leading to microvascular thrombi in various organs and contributing to multiple organ dysfunction syndrome (MODS). (medscape.com)
  • Acute DIC develops when sudden exposure of blood to procoagulants (eg, tissue factor [TF], or tissue thromboplastin) generates intravascular coagulation. (medscape.com)
  • Hence, a patient with disseminated intravascular coagulation (DIC) can present with a simultaneously occurring thrombotic and bleeding problem, which obviously complicates the proper treatment. (medscape.com)
  • [ 1 ] Factor XI enhances generation of thrombin at the platelet surface. (medscape.com)
  • Coagulation Factor X is a vitamin K-dependent plasma protease that activates thrombin in blood coagulation. (rndsystems.com)
  • Apart from activating PAR1, APC also inhibits the generation of thrombin independently, which is a vital element of healthy blood clotting. (news-medical.net)
  • the thrombin-inducing inflammatory agent, or tumor necrosis factor-α (TNF-α). (news-medical.net)
  • The prothrombinase complex is the enzymatic complex responsible for timely thrombin formation at the place of vascular injury and is composed of the enzyme, factor Xa (fXa), the non-enzymatic cofactor factor Va (fVa), and the substrate prothrombin assembled on a lipid membrane in the presence of divalent metal ions. (csuohio.edu)
  • We studied FVII gene poly- then activates factors IX and X leading to morphisms in healthy Tunisians with the the generation of thrombin [ 2 ]. (who.int)
  • In Sierra Leone during 2015-2018, we assessed LF patients' day-of-admission plasma samples for levels of proteins necessary for coagulation, fibrinolysis, and platelet function. (cdc.gov)
  • The alpha granules contain hemostatic proteins such as fibrinogen, vWf, and growth factors (eg, platelet-derived growth factor and transforming growth factors). (medscape.com)
  • The primary endpoint of LEX-209 was hemostatic efficacy-or effective blood stoppage, primary investigator Ravi Sarode, MD, noted in the press release. (pharmacytimes.com)
  • In vitro effects of a kaolin-coated hemostatic dressing on anticoagulated blood. (quikclot.com)
  • Bleeding disorders can lead to serious blood loss after an injury. (medlineplus.gov)
  • The inhibition by PIXI of factor XIa-catalyzed activation of factor IX and its capacity to prevent factor XIa inactivation by alpha 1-protease inhibitor, combined with the specificity of PIXI for factor XIa among serine proteases found in blood, suggest a role for PIXI in the regulation of intrinsic coagulation. (qxmd.com)
  • Surface-induced activation of factor XII is critical part of the intrinsic pathway of blood coagulation. (ebi.ac.uk)
  • overcome by using a highly selective procedure to remove the potentially damaging blood group antibodies and slow their production during the critical post operative period. (apollohospitals.com)
  • The reinfused plasma is depleted only of the anti-A/B but not the other proteins like the coagulation factors or other antibodies in blood. (apollohospitals.com)
  • Clotting factors function as cofactors in the blood-coagulation cascade. (medscape.com)
  • Activation of factor IX by activated factor XI (XIa) is calcium-dependent but requires no other cofactors. (medscape.com)
  • Treating the bleeding episodes involves the prompt and proper use of clotting factor concentrates. (pharmiweb.com)
  • Injury to body parts activates several systems, including the autonomic nervous system, the coagulation system, the fibrinolytic system, the complement system, and the systemic inflammatory response. (medscape.com)
  • This gene encodes coagulation factor XI of the blood coagulation cascade. (nih.gov)
  • It will not bind calcium, which is required for initiation of the clotting cascade through the extrinsic and Tissue Factor dependent pathway. (thermofisher.com)
  • Recently several reports have cleotide (designated as 0/10 bp) in the pro- focused on the association between the moter region of the gene at position -323 factor VII of the cascade coagulation and [ 13,14 ]. (who.int)
  • It can be activated in vitro by activated factor XII (XIIa). (medscape.com)
  • We have isolated monocytes from heparinised whole blood, stimulated in vitro with a component from gram negative bacteria, lipopolysaccharide (LPS), and investigated the recovery of monocytes after IMS and the LPS-induced gene-expression of TF- and TNFa-mRNA. (thermofisher.com)
  • This trait is an asymptomatic anomaly of in vitro blood coagulation. (lu.se)
  • Influence of factor XIII activity on post-operative transfusion in congenital cardiac surgery-A retrospective analysis. (medscape.com)
  • We report a blood-induced microglia gene network and show that blood proteins elicit distinct receptor-mediated transcriptional changes and signaling programs in innate immune cells. (nature.com)
  • The gene for factor XI is located on chromosome 4. (medscape.com)
  • In mice, knockout of the gene for factor XI does not lead to death in utero. (medscape.com)
  • ABSTRACT Factor VII gene polymorphisms may contribute to elevations in factor VII coagulant (FVIIc) levels that have been associated with cardiovascular risk. (who.int)
  • The Q353 allele of the factor VII gene polymorphism is associated with decreased factor VII and could be protective against cardiovascular disease. (who.int)
  • 10976 in exon 8 in the catalytic region of ing factors that may increase cardiovascu- the FVII gene and an insertion of a decanu- lar disease. (who.int)
  • Contributions of Cerebral Blood Flow to Associations Between Blood Pressure Levels and Cognition: The Age, Gene/Environment Susceptibility-Reykjavik Study. (harvard.edu)
  • Predicting severity in COVID-19 disease using sepsis blood gene expression signatures. (cdc.gov)
  • The current guidelines recommend administering four-factor PCC (4 F-PCC) rather than FFP to reverse VKA-induced coagulopathy in patients suffering from major VKA-associated bleedings, while optimal dosage protocols have not yet been clearly defined, thus differing widely [4-7]. (efim.org)
  • Activated blood coagulation factor XI may refer to: Coagulation factor IXa, an enzyme Coagulation factor XIa, an enzyme This disambiguation page lists articles associated with the title Activated blood coagulation factor XI. (wikipedia.org)
  • Sulfonated non-saccharide molecules and human factor XIa: Enzyme inhibition and computational studies. (nih.gov)
  • Transglutaminase is an enzyme, produced either by bacterial cultivation (via fermentation of plant extracts) or from the coagulation factor in porcine and bovine blood, that bonds proteins together. (marksdailyapple.com)
  • Its diagnosis is based on finding a low plasma activity of the factor in coagulating assays. (lu.se)
  • Clotting factors have names, such as fibrinogen and prothrombin. (medlineplus.gov)
  • Deletion of the blood coagulation factor fibrinogen largely reversed blood-induced microglia neurodegenerative signatures. (nature.com)
  • Defects in this factor lead to Rosenthal syndrome, a blood coagulation abnormality. (nih.gov)
  • 2. Margolis J. The kaolin clotting time: a rapid one-stage method for diagnosis of coagulation defects. (quikclot.com)
  • Blood Coagul Fibrinolysis, 2021 Dec 1. (nih.gov)
  • Comparative functional multiomics showed that blood proteins induce distinct receptor-mediated transcriptional programs in microglia and macrophages, such as redox, type I interferon and lymphocyte recruitment. (nature.com)
  • 70%. Severe cases exhibit abnormal coagulation, endothelial barrier disruption, and dysfunctional platelet aggregation but the underlying mechanisms remain poorly understood. (cdc.gov)
  • The HAdv/factor X (FX) interaction facilitates highly efficient liver transduction and protects virus particles from complement-mediated neutralization after intravenous delivery. (bvsalud.org)
  • VONVENDI is the only recombinant von Willebrand factor (VWF) replacement therapy, and the first and only treatment to reduce the frequency of bleeding episodes for severe Type 3 VWD approved by the FDA for routine prophylactic use. (hemophiliafed.org)
  • The African Region faces a high demand for blood transfusion due to bleeding related to pregnancy and childbirth, high prevalence of malaria with the attendant complication of severe malarial anemia, high rates of road traffic accidents and other types of injury as well as other indications for blood transfusion. (who.int)
  • My laboratory has a great deal of expertise in the biochemistry of coagulation and especially in the biochemistry of proteins composing prothrombinase. (csuohio.edu)
  • Thèse de Doctorat de l'Université Paris VI en Biochimie ( Ph.D. University of Paris in Biochemistry) 1989. (csuohio.edu)
  • A blood sample was collected from a jugular vein and submitted for a CBC and serum biochemistry analysis. (hindawi.com)
  • Initial rates of trichloroacetic acid-soluble 3H-release were linear over 10-30 min of incubation of Factor IX (88 nM) with CaCl2 (5 mM) and with pure (greater than 98%) Factor XIa (0.06-1.3 nM), which was prepared by incubating human Factor XI with bovine Factor XIIa. (jci.org)
  • During activation of the plasma factor XI, an internal peptide bond is cleaved by factor XIIa (or XII) in each of the two chains, resulting in activated factor XIa, a serine protease composed of two heavy and two light chains held together by disulfide bonds. (nih.gov)
  • The mechanism of this process remains unclear: in particular, it is not known whether the initial amounts of factor XIIa, an active form of factor XII, are produced purely by factor XII contacting a surface or if traces of factor XIIa pre-exist. (ebi.ac.uk)
  • The study summarizes the dominating segments of the market like the product type segment is dominated by the blood products as they used for the supply of the plasma and the plasma contains the several coagulating factors in it and they help in the process of the haemostasis. (axiommrc.com)
  • Your liver makes most of your clotting factors. (medlineplus.gov)
  • Factor XI is synthesized in the liver and megakaryocytes and is an 80-kd zymogen precursor of a serine protease. (medscape.com)
  • Damage to the liver leads to reduction in the synthesis of Case management started and was led by members with experience clotting factors. (who.int)
  • Massive hemorrhage, defined as blood loss in excess of one circulating volume within a 24-hour period, is a major cause of mortality after trauma or surgery. (medscape.com)
  • Understanding the physiology of massive hemorrhage, initiating massive transfusion, and preparing adequate blood inventories are fundamental components of management. (medscape.com)
  • Several plasma protease inhibitors that circulate in high concentrations are capable of inhibiting factor XIa. (medscape.com)
  • 1. Griffin J.H. Role of surface in surface-dependent activation of Hageman factor (blood coagulation Factor XII). (quikclot.com)
  • 255:5703-5707) for Factor IX activation by Factor VIIa plus tissue factor. (jci.org)
  • The pathophysiology of massive blood loss is complex, comprising a wide range of physiologic derangements arising from tissue injury, bleeding, and transfusion of blood or blood products. (medscape.com)
  • Human tissue factor (TF) is the initiator of blood coagulation. (oldcitypublishing.com)
  • The main challenge for large bone defect repair and regeneration remains the inadequate recruitment of mesenchymal stem cells (MSCs), reduced vascularization, and decreased growth factors stimulation within the scaffold construct to support cell viability and tissue growth. (frontiersin.org)
  • Alternative polarization with interleukin-4 and IL-13 led to a macrophage phenotype characterized by increased tissue factor (TF) production and release and by an increase in extracellular vesicle production. (haematologica.org)
  • In contrast to monocytes, human macrophages did not show increased tissue factor expression upon stimulation with lipopolysaccharide and interferon-γ. (haematologica.org)
  • Blood monocytes are "blood stream passengers" en route to various tissue compartments where they are involved in numerous functions, including defence mechanisms, producing coagulation factors and cytokines, and phagocytosing various bacterial constituents and cellular debris (apoptotic bodies). (thermofisher.com)
  • These cells may be activated by a wide range of stimuli, such as immunological, inflammatory or bacterial components, to express a diversity of "early immediate genes", including Tissue Factor (TF) and Tumour Necrosis Factor a (TNFa) (1-3). (thermofisher.com)
  • Upon contact with tissue ferences in FVII activity levels and in geno- factor exposed by vascular injury, FVII is type frequencies depend on the ethnic cleaved to its two-chain active form, which groups [ 15 ]. (who.int)
  • Kinetic analyses of the effect of PIXI on factor XIa activity demonstrated mixed-type, noncompetitive inhibition of S2366 cleavage and of factor IX activation with Ki's of 7 x 10(-8) and 3.8 x 10(-9) M, respectively. (qxmd.com)
  • Kinetics of the Factor XIa catalyzed activation of human blood coagulation Factor IX. (jci.org)
  • The kinetics of activation of human Factor IX by human Factor XIa was studied by measuring the release of a trichloroacetic acid-soluble tritium-labeled activation peptide from Factor IX by a modification of a method described for bovine Factor IX activation by Zur and Nemerson (Zur, M., and Y. Nemerson, 1980, J. Biol. (jci.org)
  • Transgenic mice overexpressing human factor IX at persistently high levels died at much younger ages than their cohorts expressing lower levels, or nontransgenic control animals. (elsevierpure.com)
  • The median survival age of animals was inversely related to the circulatory levels of human factor IX. (elsevierpure.com)
  • Coagadex is made from human blood and may contain infectious agents, such as viruses, that can be transmitted while using this medication and cause diseases. (rxwiki.com)
  • Recombinant human factor XIII-A2 homodimer composed of 2 FXIII A-subunits. (medscape.com)
  • Prothrombin complex concentrate human-Ians can quickly improve blood coagulation in patients who are at risk of excess bleeding but need urgent surgery. (pharmacytimes.com)
  • Prothrombin complex concentrate, human-lans works by replacing these deficient blood coagulation factors. (pharmacytimes.com)
  • Biotest develops and markets immunoglobulins, coagulation factors and albumin based on human blood plasma. (pharmiweb.com)
  • A blood-vessel-on-a-chip developed at Wyss institute that consisted of microfluidic channels embedded in a clear polymer chip, coated with collagen, and lined by human endothelial cells was used to validate this theory. (news-medical.net)
  • To simulate the flow conditions within human blood vessels, whole blood was perfused through the chip along with various pro- and anti-inflammatory compounds. (news-medical.net)
  • For human coagulation factor IX it has been shown [ ( PUBMED:7606779 ) ] that the calcium-ligands form a pentagonal bipyramid. (embl.de)
  • 3. Kalafatis, M., Takahashi, Y., Girma, J.P., and Meyer, D. Localization of a collagen interactive domain of human von Willebrand Factor between amino acid residues Gly 911 and Glu 1365. (csuohio.edu)
  • This customer written article "Use of Immunomagnetic Separation, mRNA Isolation and RT-PCR for Detection of Activated Human Monocytes in Whole Blood" was published in DYNALogue 2/99 and is a good example of the combined use of cell-specific IMS followed by mRNA isolation. (thermofisher.com)
  • 3 Blood products are defined as any therapeutic substances derived from human blood, including whole blood, labile blood components and plasma-derived medicinal products. (who.int)
  • posing difficulties in selecting donors at reduced risk of infection, unstable economies, lack of suitable infrastructure to provide blood services, inadequate human resources as well as lack of conducive career development structures for BTS staff in many member states. (who.int)
  • The Food and Drug Administration (FDA) currently requires that all donations of whole blood and transfusable components as well as plasma for fractionation into injectable derivatives be subjected to a serologic test for syphilis, hepatitis B surface antigen (HBsAg), and antibody to the human immunodeficiency virus (anti-HIV). (cdc.gov)
  • The FDA also currently recommends testing donations of whole blood and components for transfusion for antibody to human T lymphotropic virus type I (anti-HTLV-I) and antibody to hepatitis C virus (anti-HCV), and is considering recommending testing for antibody to hepatitis B core antigen (anti-HBc). (cdc.gov)
  • As the researchers knew that parmodulins bind to PAR1, they aimed to find a way to activate endothelial PAR1 and decrease thrombic responses without thinning the blood, and thereby provide a better substitute for APC. (news-medical.net)
  • We were intrigued by the notion that parmodulin 2 inhibited LPS- and TNF-mediated prothrombotic effects on the endothelial surface without impairing blood clotting. (news-medical.net)
  • Brixia and qSOFA Scores, Coagulation Factors and Blood Values in Spring versus Autumn 2021 Infection in Pregnant Critical COVID-19 Patients: A Preliminary Study. (cdc.gov)
  • PIXI can prevent stable complex formation between alpha 1-protease inhibitor and factor XIa light chain as demonstrated by SDS-polyacrylamide gel electrophoresis. (qxmd.com)
  • Mathematical model of the mechanism and kinetics of blood coagulation factor XII. (ebi.ac.uk)
  • This activated plasma factor XI triggers the middle phase of the intrisic pathway of blood coagulation by activating factor IX. (nih.gov)
  • Vonvendi is the first FDA approved recombinant von Willebrand factor. (rxwiki.com)
  • Vonvendi is used to replace von Willebrand factor that is missing in people with von Willebrand disease. (rxwiki.com)
  • Your doctor will perform blood tests to check your von Willebrand factor activity and the presence of any inhibitors. (rxwiki.com)
  • Ignoring instead of chasing after coagulation factor VII during warfarin management: an interrupted time series study. (harvard.edu)
  • We have identified the molecular defect in factor V Leiden and we have delineated specific amino acid regions on the factor V/Va molecule that are crucial for their functions. (csuohio.edu)
  • Of these, the ones with the strongest affinity for this factor are (in order) the Serpin protease nexin 1, C1-esterase inhibitor, antithrombin, protease inhibitor, and plasmin inhibitor. (medscape.com)
  • The dense granules contain proaggregatory factors such as ADP, calcium, and 5-hydroxytryptamine (serotonin). (medscape.com)
  • Classical polarization is usually associated with a proinflammatory response, including the increased production of tumor necrosis factor (TNF)-α, IL-1, and IL-6. (haematologica.org)
  • A linear correlation (r greater than 0.98, P less than 0.001) was observed between initial rates of 3H-release and the concentration of Factor XIa, measured by chromogenic assay and by radioimmunoassay and added at a Factor IX:Factor XIa molar ratio of 70-5,600. (jci.org)
  • Transfusion of blood and blood products is usually necessary during a bleeding catastrophe. (medscape.com)
  • The process of ordering and checking blood may be cumbersome during massive blood transfusion. (medscape.com)
  • Transfusion of blood and blood products is not without negative consequences. (medscape.com)
  • Changing population demographics and more advanced surgical and medical procedures have increased the need for blood transfusion. (who.int)
  • Blood transfusion saves lives and improves health, but many patients requiring transfusion do not have timely access to safe blood. (who.int)
  • Reliance on family replacement donations, limited coverage and quality of testing, inappropriate blood transfusion and poorly developed quality systems pose additional challenges. (who.int)
  • These guidelines address the use of tests for the hepatitis B and C viruses to screen donations of blood and plasma collected for transfusion or further manufacture into injectable products, as well as to screen donors of organs, tissues, and semen. (cdc.gov)
  • Transmission of HBV by transfusion of blood or blood products is rare because of routine screening of blood donors for HBsAg and because of current donor selection and deferral procedures. (cdc.gov)
  • In addition, recipients of blood from paid donors were at higher risk of developing post-transfusion hepatitis than were recipients of blood from non-paid donors (10,11). (cdc.gov)
  • Your healthcare provider may give you blood tests to check for inhibitors. (rxwiki.com)
  • Thus, the results suggested that parmodulin exposure blocks the thrombotic response of endothelium to inflammatory response, without affecting blood coagulation in humans. (news-medical.net)
  • Allergic reactions may occur with coagulation factor IX . (rxwiki.com)
  • 2 ml heparinised (15 U/ml) whole blood from healthy donors (n=5) were incubated for 3 hours at 37°C, rotated (50 rpm in a GFL 3032 Incubator) in the presence or absence of 2 ng/ml LPS (E. coli Endotoxin, BioWhittaker). (thermofisher.com)
  • The provision of blood and blood products from voluntary, non remunerated donors must be the aim of all countries. (who.int)
  • Transplantation of solid organs like kidney between donors and recipients of incompatible blood group is usually contraindicated because of the risk of ""hyper acute"" rejection. (apollohospitals.com)
  • The event serves to raise awareness of the need for safe blood and blood products and to thank blood donors for their life-saving gifts of blood. (who.int)
  • Most countries have developed their national blood policies and plan, 73% of total blood collections are from voluntary blood donors, at least 98% of the blood is screened for HIV, 89% for HBV, and about 60% for HCV. (who.int)
  • More than 50% of the blood supply is still dependent on family members and paid blood donors. (who.int)
  • To decrease the potential for disease transmission, donors are screened for risk factors by medical history and for evidence of infection by specific testing. (cdc.gov)
  • Screening blood donors for HBsAg began in 1969 and became mandatory in 1972. (cdc.gov)
  • Retrospective testing of blood donors using first generation tests such as immunodiffusion to detect HBsAg, found that 52%-69% of recipients of HBsAg-positive blood developed hepatitis B (8,9). (cdc.gov)
  • Carri- blood bank donors. (who.int)
  • WHA58.13, on blood safety: proposal to establish World Blood Donor Day, urged Member States to promote the development of national blood services based on voluntary non-remunerated donation and to enact effective legislation governing their operation. (who.int)
  • Every year, on 14 June, countries around the world celebrate World Blood Donor Day (WBDD). (who.int)
  • Our data provide an interactive resource for investigation of the immunology of blood proteins that could support therapeutic targeting of microglia activation by immune and vascular signals. (nature.com)
  • The blood coagulating factors are proteins or enzymes that prevent the bleeding. (axiommrc.com)