| factor viia | <enzyme> Activated form of factor vii. Factor viia activates factor x in the extrinsic pathway of blood coagulation. Registry number: EC 3.4.21.21 (12 Dec 1998) |
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| factor viii | A coagulation (clotting) factor. Classic haemophilia (haemophilia A) is due to a congenital deficiency in the amount (or activity) of factor VIII. Factor VIII is also known as antihemophiliac factor (AHF) or antihemophiliac globulin (AHG). The gene for factor VIII (that for classic haemophilia) is on the X chromosome so females can be silent carriers without symptoms and males can be haemophiliacs. (12 Dec 1998) |
| factor viii assay | A test used to measure the activity of a blood clotting factor VIII (Von Willebrand factor). This test is usually used to monitor treatment of haemophilia. Abnormally low factor VIII assays may be seen in the following conditions: congenital deficiency of factor VIII (haemophilia), DIC and secondary fibrinolysis. This test may also be performed in the evaluation of Von Willebrand's disease. (27 Sep 1997) |
| factor viii deficiency | A sex-linked genetic disease affecting males that results from a deficiency of clotting factor VIII, a protein factor that is required for normal blood coagulation. Symptoms include easy bruising, bleeding gums, nosebleeds and bleeding into muscle tissue (haematoma) or a joint space (haemarthrosis). Treatment includes the infusion of factor VIII concentrate intravenously to restore this essential factor and normalize blood coagulation. Inheritance: sex-linked. (27 Sep 1997) |
| factor viiia | <chemical> 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 similiar in structure and generation to factor va. Chemical name: Blood-coagulation factor VIIIa, procoagulant (12 Dec 1998) |
| factor x | <chemical> 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. Chemical name: Blood-coagulation factor X (12 Dec 1998) |
| factor x assay | A test used to measure the activity of a blood clotting factor X. This test may be used to evaluate excessive bleeding. Abnormally low factor X assays may be seen in the following conditions: congenital deficiency of factor X, fat malabsorption, heparin administration, cirrhosis, vitamin K deficiency and warfarin administration. (27 Sep 1997) |
| factor x deficiency | Blood coagulation disorder usually inherited as an autosomal recessive trait, though it can be acquired. It is characterised by defective activity in both the intrinsic and extrinsic pathways, impaired thromboplastin time, and impaired prothrombin consumption. (12 Dec 1998) |
| factor X for Haemophilus | <physiology> A substance, in the form of reddish brown, microscopic, prismatic crystals, formed from dried blood by the action of strong acetic acid and common salt; called also Teichmann's crystals. Chemically, it is a hydrochloride of haematin. The obtaining of these small crystals, from old blood clots or suspected blood stains, constitutes one of the best evidences of the presence of blood. Origin: Gr. Blood. Source: Websters Dictionary (01 Mar 1998) |
| factor xa | <enzyme> Activated form of factor x that participates in both the intrinsic and extrinsic pathways of blood coagulation. It catalyses the conversion of prothrombin to thrombin in conjunction with other cofactors. Registry number: EC 3.4.21.6 (12 Dec 1998) |
| factor xi | <chemical> 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 haemophilia c. Chemical name: Blood-coagulation factor XI (12 Dec 1998) |
| factor xi deficiency | A deficiency of blood coagulation factor xi (known as plasma thromboplastin antecedent or pta or antihemophilic factor c) resulting in a systemic blood-clotting defect called haemophilia c or rosenthal's syndrome, that may resemble classical haemophilia. (12 Dec 1998) |
| factor xia | <enzyme> 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. Registry number: EC 3.4.21.27 (12 Dec 1998) |
| factor xii | <chemical> 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. Chemical name: Blood-coagulation factor XII (12 Dec 1998) |
| factor xii assay | A test used to measure the activity of a blood clotting factor XII. This test may be used to evaluate excessive bleeding. Low factor XII may be seen in cases of congenital deficiency of factor XII, heparin administration and liver disease. (27 Sep 1997) |
| Bittner's milk factor | Member of the retrovirus subfamily Oncornavirinae, antigenically distinct from the murine leukaemia-sarcoma complex, that is associated with adenocarcinomatous tumours of the mammary gland, commonly latent in wild and laboratory mice and causing cancer only in genetically susceptible strains under certain hormonal influences. Synonym: Bittner agent, Bittner virus, Bittner's milk factor, mammary cancer virus of mice, milk factor, mouse mammary tumour virus. (05 Mar 2000) |
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| blood clotting factor | <haematology> Any of a number of different protein factors which, when acting together, can form a blood clot shortly after platelets have broken at the site of the wound. The factors have Roman numeral names, like VII, VIII, IX, X, XI, and XIII. Defects in the genes which code for any of these factors result in genetic diseases like haemophilia, which results from a defect in the gene for factor VIII or IX. (09 Oct 1997) |
| blood coagulation factor inhibitors | 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. (12 Dec 1998) |
| brain-derived growth factor | <growth factor> Small basic protein purified from pig brain, a member of the family of neurotrophic factors that also includes Nerve Growth Factor and neurotrophin 3. In contrast to nerve growth factor, brain-derived neurotrophic factor is predominanantly (though not exclusively) localised in the CNS. It supports the survival of primary sensory neurons originating from the neural crest and ectodermal placodes that are not responsive to NGF. In the brain brain-derived neurotrophic factor has a trophic action on retinal, cholinergic, and dopaminergic neurons, and in the peripheral nervous system it acts on both motor and sensory neurons. Acronym: BDGF (12 Dec 1998) |
| brain-derived neurotrophic factor | <growth factor> Small basic protein purified from pig brain, a member of the family of neurotrophic factors that also includes Nerve Growth Factor and neurotrophin 3. In contrast to nerve growth factor, brain-derived neurotrophic factor is predominanantly (though not exclusively) localised in the CNS. It supports the survival of primary sensory neurons originating from the neural crest and ectodermal placodes that are not responsive to NGF. In the brain brain-derived neurotrophic factor has a trophic action on retinal, cholinergic, and dopaminergic neurons, and in the peripheral nervous system it acts on both motor and sensory neurons. Acronym: BDGF (12 Dec 1998) |
| branching factor | 1,4-alpha-glucan-branching enzyme. (05 Mar 2000) |
| BT factor | <biochemistry> _ Hydroxy _ trimethyl aminobutyric acid. Compound that transports long chain fatty acids across the inner mitochondrial membrane in the form of acyl carnitine. Sometimes referred to as Vitamin Bt or Vitamin B7. (18 Nov 1997) |
| CAMP factor | A test to identify Group B beta-streptococci based on their formation of a substance (CAMP factor) that enlarges the area of haemolysis formed by streptococcal beta-haemolysin. Origin: Christie, Atkins, and Munch-Petersen, developers of the t. (05 Mar 2000) |
| capacity factor | <physics> This is the ratio of the average power output from an electric power plant to the plant's rated capacity. A capacity factor is ideally unity, but invariably less. Capacity factors vary widely between types of electric plants (for example, nuclear, solar, coal, etc.), and can even vary widely for a single type of power plant. <radiobiology> Index (typically in percent) indicating the average power supplied by an energy plant, relative to its maximum rated capacity. Synonym: plant factor, load factor. (13 Jan 1998) |
| capillary permeability factor | A mixture of bioflavonoids extracted from plants (especially citrus fruits). It reduces the permeability and fragility of capillaries and is useful in the treatment of certain cases of purpura that are resistant to vitamin C therapy. See: hesperidin, quercetin, rutin. Synonym: capillary permeability factor, citrin, permeability vitamin. (05 Mar 2000) |
| p60 tumour necrosis factor receptor-associated kinase | <enzyme> Interacts with and causes phosphorylation of the cytoplasmic domain of the tnf receptor Registry number: EC 2.7.10.- Synonym: p60 tnf receptor-associated kinase, p60-trak (26 Jun 1999) |
| galactagogue factor | <endocrinology> A factor 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. (05 Mar 2000) |
| galactopoietic factor | <protein> Pituitary lactogenic hormone (23 kD) Synthesised on endoplasmic reticulum bound ribosomes as preprolactin that has an N terminal signal peptide that is cleaved from the mature form. The conversion of preprolactin to prolactin has been much used as an assay for membrane insertion. (18 Nov 1997) |
| macrophage-activating factor | An agent that stimulates macrophages to attack and ingest cancer cells. They are secreted by stimulated lymphocytes that prime macrophages to become non-specifically cytotoxic to tumours. They also modulate the expression of macrophage cell surface ia antigens. One maf is interferon-gamma (interferon type II). Other factors antigenically distinct from ifn-gamma have also been identified. (12 Dec 1998) |
| macrophage colony-stimulating factor | <growth factor> A glycoprotein growth factor that causes the committed cell line to proliferate and mature into macrophages. A cytokine synthesised by mesenchymal cells that stimulates pluripotent stem cells of bone marrow into differentiating towards the production of monocytes (mononuclear phagocytes). The compound stimulates the survival, proliferation, and differentiation of haematopoietic cells of the monocyte-macrophage series. It is a disulfide-bonded glycoprotein dimer with a mw of 70 kD and binds to a single class of high affinity receptor which is identical to the product of the c-fms proto-oncogene. See: colony-stimulating factors. Chemical name: Colony-stimulating factor 1 Acronym: M-CSF (12 Dec 1998) |