factor (fak´ter)

1. One of the contributing causes in any action. 2. One of the components that by multiplication makes up a number or expression. 3. gene 4. A vitamin or other essential element. 5. An event, characteristic, or other definable entity that brings about a change in a health condition. 6. A categorical independent variable, used to identify, by means of numerical codes, membership in a qualitatively identifiable group; for example, "overcrowding is a factor in disease transmission." [L. maker, causer, fr. facio, to make]
f. 3 1. operational name given to an incompletely characterized selenium-containing natural product which, in minute amounts, prevents liver damage in rats due to deficiency of vitamin E; 2. f. III in the vitamin B12 series, 5-hydroxybenzimidazole, analogue of the usual B12 nucleotide components.
f. A See properdin f. A.
ABO f.'s see Blood Groups appendix.
accelerator f. f. V
acetate replacement f. lipoic acid
adrenal weight f. a postulated substance of adenohypophysial origin responsible for maintenance of the weight of the adrenal cortex.
adrenocorticotropic releasing f. hormone produced by hypothalamus that causes pituitary to secrete adrenocorticotropic hormone.
angiogenesis f. a substance of 2000 to 20,000 MW which is secreted by macrophages and stimulates neovascularization in healing wounds or in the stroma of tumors.
animal protein f. (APF) vitamin B12
antialopecia f. inositol
antianemic f. vitamin B12
antiberiberi f. thiamin
anti-black-tongue f. nicotinic acid
anticomplementary f. a f. that interferes with the action or function of complement.
antidermatitis f. pantothenic acid
antihemophilic f. A (AHF) f. VIII
antihemophilic f. B f. IX
antihemorrhagic f. vitamin K
antineuritic f. thiamin
antinuclear f. (ANF) a f., usually antibodies, present in serum with strong affinity for nuclei and detected by fluorescent antibody technique; present in lupus erythematosus, rheumatic arthritis, and certain other autoimmune conditions; may also be present at lower levels in normal individuals.
antipellagra f. nicotinic acid
antipernicious anemia f. (APA) 1. vitamin B12 2. specifically, cyanocobalamin.
antisterility f. vitamin E (2)
atrial natriuretic f. (ANF) an early name given to a natriuretic f. derived from cardiac atria. The term is no longer correct because the f. is now known to be a peptide.
f. B See properdin f. B.
BT f. carnitine
bacteriocin f.'s bacteriocinogenic plasmids, under plasmid
B-cell differentiating f. interleukin-4
B cell differentiation/growth f.'s various substances, usually obtained from the supernatant of T cell cultures, such as interleukin 4, 5, and 6. These substances are necessary for B cell growth, maturation, and differentiation into plasma cells or B memory cells.
B-cell stimulatory f. 2 interleukin-6
bifidus f. an unidentified substance associated with Lactobacillus bifidus subsp. pennsylvanicus, present in mammalian milk.
biotic f.'s environmental f.'s or influences resulting from the activities of living organisms, as contrasted to those resulting from climatic, geological, or other f.'s.
Bittner's milk f. mammary tumor virus of mice
branching f. 1,4-a-glucan-branching enzyme.
C f.'s coupling f.'s
CAMP f. See CAMP test.
capillary permeability f. vitamin P
Castle's intrinsic f. intrinsic f
Christmas f. f. IX
citrovorum f. (CF) folinic acid
clearing f.'s lipoprotein lipases that appear in plasma during lipemia and catalyze hydrolysis of triglycerides only when the latter are bound to protein and when an acceptor (e.g., serum albumin) is present, thus "clearing" the plasma.
clotting f. any of the various plasma components involved in the clotting process.coagulation f;
coagulation f. clotting f
cobra venom f. a component of cobra venom that renders C3 proactivator (properdin factor B) susceptible to factor D of the properdin system, leading to activation of C3 and other components of complement and lysis of unsensitized erythrocytes.
coenzyme f. dihydrolipoamide dehydrogenase
colony-stimulating f.'s (CSF) a group of glycoprotein growth f.'s regulating differentiation in mycloid cell lines. These substances act in either paracrine or autocrine fashion on marrow cells, appear to act synergistically in complex and poorly understood ways; each appears to have the ability to exert actions on several lines of progenitor cells, and to influence end cell function.
complement chemotactic f. the activated complex of the fifth, sixth, and seventh components of complement (C567) which induces chemotaxis in the case of polymorphonuclear leukocytes.
complement f. I a heterodimeric glycoprotein; a deficiency results in uncontrolled activation of C3.
corticotropin releasing f. (CRF) 1. corticoliberin 2. corticotropin releasing hormone
coupling f.'s proteins that restore phosphorylating ability to mitochondria that have lost it, i.e., have become "uncoupled" so that oxidation and electron transport no longer produces ATP. Usually termed coupling factor F1, F2, etc.C f.'s;
f. D See properdin f. D.
debranching f.'s debranching enzymes, under enzyme
decapacitation f. a f., postulated to be present in epididymal fluid and seminal plasma, that prevents the capacitation of spermatozoa.
diabetogenic f. rarely used term for a f. in crude extracts of the anterior lobe of the hypophysis that produces degenerative changes in the islet cells of the pancreas and causes permanent diabetes.
diffusing f. hyaluronidase (1)
direct lytic f. of cobra venom cobrotoxin
Duran-Reynals permeability f. , Duran-Reynals spreading f. hyaluronidase (1)
f. E See properdin f. E.
elongation f. proteins that catalyze the elongation of peptide chains during protein biosynthesis.transfer f. (3) ;
endothelial relaxing f. (en´do-the´li-al) a molecule functioning as a neurotransmitter and produced by activated macrophages. It is capable of killing tumor cells, parasites, and intracellular bacteria.
endothelium-derived relaxing f. (EDRF) diffusible substances produced by endothelial cells that cause vascular smooth muscle relaxation; nitric oxide (NO) is one such substance.
eosinophil chemotactic f. of anaphylaxis a peptide (MW 500 to 600) that is chemotactic for eosinophilic leukocytes and is released from disrupted mast cells.
epidermal growth f. (EGF) a heat-stable antigenic protein isolated from the submaxillary glands of male mice; when injected into newborn animals it accelerates eyelid opening and tooth eruption, stimulates epidermal growth and keratinization, and, in larger doses, inhibits body growth and hair development and produces fatty livers.
erythrocyte maturation f. vitamin B12
essential food f.'s those substances required in the diet: certain amino acids and unsaturated fatty acids, vitamins, essential minerals, etc.
extrinsic f. dietary vitamin B12.
F f. F plasmid
fermentation Lactobacillus casei f. pteropterin
fertility f. F plasmid
fibrin-stabilizing f. f. XIII
filtrate f. former term for pantothenic acid.
Fitzgerald f. high molecular weight kininogen
Flaujeac f. high molecular weight kininogen
Fletcher f. prekallikrein
follicle-stimulating hormone-releasing f. (FRF, FSH-RF) folliberin
G f. 1. the single common variance or f. that is common to (i.e., empirically intercorrelates with) different intelligence tests (general). 2. a substance required for the growth of a specific organism.
galactagogue f. a f. in extracts of the posterior lobe of the hypophysis that, by stimulating the smooth muscle of the lobulo-alveolar system of the mammary gland, causes a flow of milk from the nipple.
galactopoietic f. prolactin
glass f. f. XII
glucose tolerance f. a water-soluble complex containing chromium needed for normal glucose tolerance.
glycotropic f. a principle in extracts of the anterior lobe of the hypophysis that raises the blood sugar and antagonizes the action of insulin; purified pituitary growth hormone produces an identical effect.insulin-antagonizing f;
f. Gm a f. that determines certain of the allotypes of human immunoglobulins; found only on the gamma chains of IgG (gamma-globulin).
gonadotropin-releasing f. gonadoliberin (1)
granulocyte colony-stimulating f. (G-CSF) (gran´yu-lo-sIt) glycoproteins that are synthesized by a variety of cells and are involved in growth and differentiation of hematopoietic stem cells. In addition, these f.'s stimulate the end-cell functional activity of stem cells. See also colony-stimulating f.'s.
granulocyte-macrophage colony-stimulating f. (GM-CSF) (gran´u-lo-sIt) a glycoprotein secreted by macrophages or bone stromal cells that functions as a growth factor for myeloid progenitor cells such as granulocytes, macrophages, and eosinophils. See also colony-stimulating f.'s.
growth f.'s proteins involved in cell differentiation and growth.Growth factors are essential to the normal cell cycle, and are thus vital elements in the life of animals from conception to death. Among other things, they mediate fetal development, play a role in maintenance and repair of tissues, stimulate production of blood cells, and, gone awry, participate in cancerous processes.
growth hormone-releasing f. (GHRF, GH-RF) somatoliberin
f. H 1. former designation for biotin; 2. vitamin B12 analogue or precursor; 3. a glycoprotein that regulates the activity of complement factor C3b; a deficiency results in the lack of inhibition of the alternative hemolytic pathway leading to continuous activation and consumption of factor C3 (hemolytic uremic syndrome).
Hageman f. f. XII
HG f. glucagon
human antihemophilic f. a lyophilized concentrate of f. VIII, obtained from fresh normal human plasma; used as a hemostatic agent in hemophilia.antihemophilic globulin (2), human antihemophilic fraction;
hyperglycemic-glycogenolytic f. (HGF) glucagon
f. I in the clotting of blood a f. that is converted to fibrin through the action of thrombin. See also fibrinogen.
f. II a glycoprotein converted in the clotting of blood to thrombin by factor Xa, platelets, calcium ions, and factor V. See also prothrombin.
f. IIa thrombin
f. III in the clotting of blood, tissue f. or thromboplastin; it initiates the extrinsic pathway by reacting with f. VII and calcium to form f. VIIa. See thromboplastin.
inhibition f. migration-inhibitory f
initiation f. (IF) one of several soluble proteins involved in the initiation of protein or RNA synthesis.
insulin-antagonizing f. glycotropic f
insulin-like growth f.'s (IGF) peptides whose formation is stimulated by growth hormone. These peptides bring about peripheral tissue effects of that hormone and have high (about 70%) homology to human insulin.somatomedins;
intrinsic f. (IF) a relatively small mucoprotein (MW about 50,000) secreted by the neck cell of the gastric glands and required for adequate absorption of vitamin B12; deficiency results in pernicious anemia.Castle's intrinsic f;
f. Inv a f. that determines certain of the allotypes of human immunoglobulins; found on the kappa chains of IgG, IgA, IgM, and Bence Jones protein.
ischemia-modifying f.'s various factors that play a role in determining the extent of necrosis with cerebral stroke; these include blood viscosity and osmolality, the blood pressure, and the anatomy of the neck and intracranial arteries.
f. IV in the clotting of blood, calcium ions.
f. IX in the clotting of blood, also known as: Christmas f. (Biggs and Macfarlane), plasma thromboplastin component (Aggeler), antihemophilic globulin B (Cramer), plasma thromboplastin f. B (Aggeler), plasma f. X (Shulman), antihemophilic f. B, and platelet cofactor II. F. IX is required for the formation of intrinsic blood thromboplastin and affects the amount formed (rather than the rate). Its active form, f. IXa (EC is a serine proteinase converting f. X to f. Xa by cleaving an arginine-isoleucine bond. Deficiency of f. IX causes hemophilia B.antihemophilic f. B, antihemophilic globulin B, Christmas f., plasma f. X, plasma thromboplastin component, plasma thromboplastin f. B, platelet cofactor II;
labile f. f. V
Lactobacillus bulgaricus f. (LBF) pantetheine
Lactobacillus casei f. folic acid (2)
lactogenic f. prolactin
Laki-Lorand f. f. XIII
LE f.'s antinuclear immunoglobulins in plasma of persons with disseminated lupus erythematosus, associated with positive LE tests.
lethal f. See genetic lethal.
leukocytosis-promoting f. a substance obtained by Menkin from inflammatory exudates; it stimulates leukocytosis.
leukopenic f. a principle obtained by Menkin from inflammatory exudates; it causes leukopenia when injected into normal animals.
lipotropic f. choline
liver filtrate f. former term for pantothenic acid.
liver Lactobacillus casei f. folic acid (2)
L-L f. f. XIII
luteinizing hormone/follicle-stimulating hormone-releasing f. (LH/FSH-RF) gonadoliberin (2)
luteinizing hormone-releasing f. (LH-RF, LRF) former name for luteinizing hormone-releasing hormone.
lymph node permeability f. (LNPF) a substance, released by lymphocytes when stimulated or damaged, that increases capillary permeability and the accumulation of mononuclear cells.
macrophage-activating f. (MAF) (mak´ro-faj) group of lymphokines that induces macrophage activation. Two major macrophage activating f.'s are interferon gamma and interleukin-4.
macrophage colony-stimulating f. (M-CSF) a glycoprotein growth f. that causes the committed cell line to proliferate and mature into macrophages. See also colony-stimulating f.'s.
maize f. zeatin
mammotropic f. prolactin
maturation f. vitamin B12
melanotropin-releasing f. melanoliberin
mesodermal f. a protein that can induce the formation of kidney and muscle primordia in embryos.
migration-inhibitory f. (MIF) a soluble, nondialyzable substance that is produced by sensitized lymphocytes (i.e., lymphocytes from a sensitized animal) when exposed to the specific antigen, and that causes adherence and inhibition of migration of macrophages.inhibition f;
milk f. mammary tumor virus of mice
monocyte derived neutrophil chemotactic f. (MDNCF) interleukin-8
mouse antialopecia f. inositol
müllerian inhibiting f. müllerian inhibiting substance
müllerian regression f. , müllerian duct inhibitory f. a nonsteroidal substance of fetal testicular origin that acts unilaterally to inhibit development of the paramesonephric (müllerian) ducts and acts with testosterone to promote development of the vas deferens and related structures.
multi-colony-stimulating f. (multi-CSF) interleukin-3
myocardial depressant f. (MDF) a toxic f. in shock that impairs cardiac contractility; probably a peptide released with underperfusion of the splanchnic area at the release of proteolytic enzymes from the pancreas.
natural killer cell stimulating f. (NKSF) interleukin-12
nephritic f. a serum protein (possibly an IgG autoantibody), found in some patients with membranoproliferative glomerulonephritis and hypocomplementemia, which, together with the cofactors of the alternate pathway of complement activation, cleaves the third component of complement (C3).
nerve growth f. (NGF) a protein (MW about 26,000) that controls the development of sympathetic postganglionic neurons and possibly also sensory (dorsal root) ganglion cells in mammals; similar, but not identical, factors have been isolated from the venoms of several species of snakes; it has been isolated from the submaxillary glands of male mice, and when injected into newborn animals, sympathetic ganglia become hyperplastic and hypertrophic; stimulates synthesis of nucleic acids and protein.
neural f. a protein that can induce the formation of notochord tissue in embryos.
neutrophil activating f. (NAF) interleukin-8
neutrophil chemotactant f. (nu´tro-fil ke´mo-tak-tant) interleukin-8 See interleukin-8.
osteoclast activating f. a lymphokine that stimulates bone resorption and inhibits bone-collagen synthesis.
psi f. psi f
f. P a chemical (postulated by T. Lewis), formed in ischemic skeletal or cardiac muscle, held to be responsible for the pain of intermittent claudication and angina pectoris.
P f. see P blood group, Blood Groups appendix.
pellagra-preventing f. (p-p f.) nicotinic acid
plasma labile f. f. V
plasma thromboplastin f. (PTF) f. VIII
plasma thromboplastin f. B f. IX
plasma f. X f. IX
plasmin prothrombins conversion f. (PPCF) f. V
platelet f. 3 a blood coagulation factor derived from platelets; chemically, a phospholipid lipoprotein that acts with certain plasma thromboplastin f.'s to convert prothrombin to thrombin.
platelet-activating f. (PAF) platelet-aggregating f
platelet-aggregating f. (PAF) phospholipid mediator of platelet aggregation, inflammation, and anaphylaxis. Produced in response to specific stimuli by a variety of cell types, including neutrophils, basophils, platelets, and endothelial cells. Several molecular species of PAF have been identified which vary in the length of the O-alkyl side chain. It is an important mediator of bronchoconstriction.platelet-activating f;
platelet-derived growth f. (PDGF) a f. in platelets that is mitogenic for cells at the site of a wound, e.g., causing endothelial proliferation; cationic glycoprotein mitogen for fibroblasts, smooth muscle cells, and glial cells. Principal f. in serum required for the growth and proliferation of mesenchymal derived cells in tissue culture.
platelet tissue f. thromboplastin
p-p f. abbreviation for pellagra-preventing f.
predisposing f.'s attitudinal, personality, and related f.'s that motivate and guide an individual to take certain health actions.
prolactin-inhibiting f. (PIF) prolactostatin
prolactin-releasing f. (PRF) prolactoliberin
properdin f. A a component of the properdin system; a hydrazine-sensitive beta1-globulin (mw about 180,000), now known to be C3 (third component of complement).
properdin f. B a normal serum protein (mw 95,000) and a component of the properdin system.beta2-glycoprotein II, C3 proactivator, cobra venom cofactor, glycine-rich beta-glycoprotein;
properdin f. D a normal serum a-globulin (mw about 25,000) required in the properdin system.C3 proactivator convertase, glycine-rich beta-glycoproteinase;
properdin f. E a serum protein (mw 160,000) required for activation of C3 (third component of complement) by cobra venom factor. See also properdin system.
protein f. the f. (6.25) by which the nitrogen content of a protein is multiplied to give the amount of protein.
psi f. a protein responsible for the specific initiation of the RNA polymerase-catalyzed reaction at the promoter sites of genes.psi f;
pyruvate oxidation f. lipoic acid
quality f. (QF) 1. a f. by which absorbed radiation doses are multiplied; 2. to obtain, for radiation protection purposes, a quantity that expresses the approximate biological effectiveness of the absorbed dose.
rho f. rho f
R f.'s resistance plasmids, under plasmid
radiation weighting f. in radiation protection, a f. weighting the absorbed dose of radiation of a specific type and energy for its effect on tissue. See equivalent dose.
recognition f.'s f.'s which effect "recognition" of target antigens by polymorphonuclear leukocytes; apparently the Fc portion of antibody molecules and the activated third component of complement (C3), for both of which phagocytes have receptor sites.
relaxation f. substance presumably involved in the return of muscle fibrils to the resting state after nervous stimulation ceases, postulated to act by withdrawing Ca2+ from myosin-ATPase sites.
releasing f. (RF) 1. substances, usually of hypothalamic origin, capable of accelerating the rate of secretion of a given hormone by the anterior pituitary gland; 2. f.'s required in the termination phase of either RNA biosynthesis or protein biosynthesis.termination f; liberins, releasing hormone, statins;
resistance f.'s resistance plasmids, under plasmid
resistance-inducing f. (RIF) an agent from normal chick embryos that interferes with multiplication of the avian leukosis-sarcoma virus, and is seemingly an avirulent leukosis virus antigenically related to the avian leukosis-sarcoma virus.
resistance-transfer f. the transfer gene of the resistance plasmid.
Rh f. the antigen of the Rh blood group system. See Blood Groups Appendix.Rhesus f;
Rhesus f. see Blood Groups Appendix.Rh f
rheumatoid f.'s (RF) antibodies in the serum of individuals with rheumatoid arthritis that react with antigenic determinants or immunoglobulins that enhance agglutination of suspended particles coated with pooled human gamma-globulin. Rheumatoid f.'s also occur in other autoimmune and certain infectious diseases.
rho f. a termination f. that releases RNA from the DNA template.rho f;
risk f. a single characteristic statistically associated with, although not necessarily causally related to, an increased risk of morbidity or mortality e.g., smoking as a risk f. for heart disease.
sigma f. sigma f
S f. the individual variables, or empirically most minute subclusters of intercorrelations or common variance, found in different intelligence tests (specific).
secretor f. the capacity to secrete antigens of the ABO blood group in saliva and other body fluids, controlled by a pair of allelic genes designated Se and se (or S and s), with the Se phenotype dominant to se; the saliva of genotypes SeSe and Sese contains the blood group substances A, B, or H found in their erythrocytes; the saliva of nonsecretors (genotype sese) contains no blood group substance; tests for ABH secretion are useful in genetic linkage and population studies; the secretor phenomenon is also closely associated with the Lewis blood group.
sex f. F plasmid
sigma f. a f. that inhibits the nonspecific DNA binding of RNA polymerase, as well as helping to identify the starting point of transcription.sigma f;
slow-reacting f. of anaphylaxis (SRF-A) slow-reacting substance
SLR f. , Streptococcus lactis R f. rhizopterin
somatotropin release-inhibiting f. (SRIF, SIF) somatostatin
somatotropin-releasing f. (SRF) somatoliberin
spreading f. hyaluronidase (1)
stable f. f. VII
stringent f. the gene product (an enzyme) that is crucial to the cellular response of decreased ribosome production as a result of amino acid starvation. See also stringent response.
Stuart f. , Stuart-Prower f. f. X
sulfation f. somatomedin
sun protection f. (SPF) the ratio of the minimal ultraviolet dose required to produce erythema with and without a sunscreen; highly effective sunscreens have an SPF of 15 or more.
T-cell growth f. interleukin-2
T-cell growth f.-1 interleukin-2
T-cell growth f.-2 interleukin-4
termination f. releasing f. (2)
testis-determining f. (TDF) the product of a gene on the short arm of the Y chromosome that is responsible for production of testes.
thymic lymphopoietic f. a glycoprotein (MW about 12,000) that has been extracted from thymus; this thymus-produced hormone(s) confers immunological competence on thymus-dependent cells and induces lymphopoiesis.
thyroid-stimulating hormone-releasing f. (TSH-RF) thyroliberin
thyrotoxic complement-fixation f. a form of thyrotoxin; an antigen found most readily in thyroid tissue from thyrotoxic individuals; known to be chemically and immunologically distinct from thyroglobulin, and fixes complement when combined with antibody related to the gamma-globulin fraction of serum. With the exception of extremely small concentrations, the antigen is rarely found in normal glands or in diseased glands that are not associated with thyrotoxicosis; it is probably an intracellular substance (possibly a constituent of the "microsomal fraction"), and does not contain iodine in significant quantity. Not related to the complement-fixation reaction occurring with serum in Hashimoto's disease, in which the antigen is thyroglobulin.
thyrotropin-releasing f. (TRF) former name for thyrotropin-releasing hormone.
tissue f. thromboplastin
tissue weighting f. in radiation protection, a f. weighting the equivalent dose in a particular tissue or organ in terms of its relative contribution to the total deleterious effects resulting from uniform irradiation of the whole body. See effective dose.
transfer f. 1. the transfer gene of a conjugative plasmid, especially of the resistance plasmid; 2. a dialyzable extract that is obtained from the leukocytes of a person with a delayed-type sensitivity and that, following injection into the skin of a nonsensitive person, transfers the specific sensitivity to the recipient; 3. elongation f
transforming f. the DNA responsible for bacterial transformation.
transforming growth f.'s (TGF) two polypeptide growth f.'s; TGF-a stimulates growth of many epidermal and epithelial cells and is obtained from conditioned media of transformed or tumor cells; TGF-beta is obtained from kidney and platelets and may even have inhibitory effects on certain cells.
transforming growth f. a (TGFa) a cytokine made by tumor and transformed cells that is associated with growth and differentiation. It is also made in normal tissues during embryogenesis and in certain adult tissues.
transforming growth f. beta (TGFbeta) a cytokine that has multifunctional properties including interfering with other cytokines. It is produced by platelets and bone cells but can be made by many other cell types.
transmethylation f. choline
tumor angiogenic f. (TAF) a substance released by solid tumors which induces formation of new blood vessels to supply the tumor.
tumor necrosis f. (TNF) cachectin
tumor necrosis f.-beta A cytolytic factor that is produced by CD4 and CD8 T cells after their exposure to an antigen.
uncoupling f.'s uncouplers
uterine relaxing f. (URF) relaxin
f. V in the clotting of blood, also known as: proaccelerin (Owren), labile or plasma labile f. (Quick), plasma accelerator globulin (Ware and Seegars), thrombogene (Nolf), prothrombokinase (Milstone), plasmin prothrombins conversion f. (Stefanini), component A of prothrombin (Quick), prothrombin accelerator (Fantl and Nance), cofactor of thromboplastin (Honorato), and accelerator f. F. V does not have enzymatic action itself but participates in the common pathway of coagulation by binding f. Xa to platelet surfaces. Deficiency of this f. leads to a rare hemorrhagic tendency known as parahemophilia or hypoproaccelerinemia, with autosomal recessive inheritance; heterozygous individuals are recognized by reduced levels of f. V but have no bleeding tendency.accelerator f., labile f., plasma accelerator globulin, plasma labile f., plasmin prothrombins conversion f., proaccelerin, prothrombin accelerator, prothrombokinase, thrombogene;
f. V1a cobyric acid
f. Va in the clotting of blood, accelerin.
f. VII in the clotting of blood, also known as: proconvertin (Owren), convertin, serum prothrombin conversion accelerator (de Vries, Alexander), stable f. (Stefanini), cofactor V (Owren), prothrombinogen (Quick), cothromboplastin (Mann and Hurn), serum accelerator (Jacox). F. VII forms a complex with tissue thromboplastin and calcium to activate f. X. F. VII is known to be involved in: 1) the congenital deficiency of f. VII, with purpura and bleeding from mucous membranes, autosomal recessive inheritance; 2) the acquired deficiency of f. VII in association with a deficiency of vitamin K, the neonatal period, and the administration of prothrombinopenic drugs; 3) the acquired excess of f. VII in some patients with thromboembolism. It accelerates the conversion of prothrombin to thrombin, in the presence of tissue thromboplastin, calcium, and f. V.proconvertin, prothrombinogen, serum accelerator, serum prothrombin conversion accelerator, stable f;
f. VIII in the clotting of blood, also known as: antihemophilic f. A (Brinkhous), antihemophilic globulin (1) (Patek and Taylor), antihemophilic globulin A (Cramer), plasma thromboplastin f. (Ratnoff), plasma thromboplastin f. A (Aggeler), thromboplastic plasma component (Shinowara), thromboplastinogen (Quick), prothrombokinase (Feissly), platelet cofactor (Johnson), plasmokinin (Laki), thrombokatilysin (Leggenhager), and proserum prothrombin conversion accelerator. F. VIII participates in the clotting of the blood by forming a complex with f. IXa, platelets, and calcium and enzymatically catalyzing the activation of f. X. Deficiency of f. VIII is associated with classic hemophilia A. F. VIII:C is the coagulant component of f. VIII which, in normal persons, circulates in the plasma complexed with f. VIIIR (von Willebrand f.), the plasma f. VIII related protein, a large glycoprotein component that is synthesized by endothelial cells and megakaryocytes, and circulates in the plasma where it binds to arteries that have lost their endothelial cell linings, creating a surface to which platelets adhere. Disorders involving f. VIIIR form a heterogenous group of abnormalities called von Willebrand's disease. A deficiency of f. can lead to impaired blood coagulation.antihemophilic f. A, antihemophilic globulin A, antihemophilic globulin (1), plasma thromboplastin f., plasmokinin, platelet cofactor I, proserum prothrombin conversion accelerator, prothrombokinase, thrombokatilysin, thromboplastinogen;
von Willebrand f. See f. VIII.
W f. biotin
Williams f. high molecular weight kininogen
f. X in the clotting of blood, also known as: Stuart f., Stuart-Prower f., prothrombase, and prothrombinase. Its active form, f. Xa (EC, is formed from f. X by limited proteolysis and assists in the conversion of prothrombin to thrombin. A deficiency of f. X will lead to impaired blood coagulation.prothrombinase, Stuart f., Stuart-Prower f;
f. X for Haemophilus hemin
f. XI in the clotting of blood, also known as plasma thromboplastin antecedent, a component of the contact system which is absorbed from plasma and serum by glass and similar surfaces. Its active form, f. XIa (EC, is a serine proteinase converting f. IX to f. IXa. Deficiency of f. XI results in a hemorrhagic tendency and is caused by an autosomal recessive gene.plasma thromboplastin antecedent;
f. XII in the clotting of blood, also known as glass f. and Hageman f. When activated by glass or otherwise to its active form, f. XIIa (EC, a serine proteinase, it activates f.'s VII and XI and converts f. XI to its active form, f. XIa. Deficiency of f. XII results in great prolongation of the clotting time of venous blood, but only rarely in a hemorrhagic tendency; deficiency is caused by an autosomal recessive gene.glass f., Hageman f;
f. XIII in the clotting of blood, also known as: fibrin-stabilizing f., Laki-Lorand f., and L-L f. It is catalyzed by thrombin into its active form, f. XIIIa, which cross-links subunits of the fibrin clot to form insoluble fibrin.fibrin-stabilizing f., L-L f., Laki-Lorand f;


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