| helper factor | A group of factors apparently produced by helper T lymphocytes that act specifically or non-specifically to transfer T-cell help to other classes of lymphocytes. The existence of specific T-cell helper factor is uncertain. (18 Nov 1997) |
|---|---|
| prolactin-inhibiting factor | A substance of hypothalamic origin capable of inhibiting the synthesis and release of prolactin. Synonym: prolactin-inhibiting factor, prolactin-inhibiting hormone. Origin: prolactin + G. Stasis, standing still, + -in (05 Mar 2000) |
| prolactin-releasing factor | A substance of hypothalamic origin that stimulates the release of prolactin. Synonym: prolactin-releasing factor, prolactin-releasing hormone. Origin: prolactin + L. Libero, to free, + -in (05 Mar 2000) |
| properdin factor A | A component of the properdin system; a hydrazine-sensitive b1-globulin (mw about 180,000), now known to be C3 (third component of complement). (05 Mar 2000) |
| properdin factor b | <enzyme> A glycine-rich, heat-labile beta-glycoprotein found in blood. It is a proactivator of complement 3 in the alternate pathway of complement activation. Factor b is converted by factor d to c3 convertase. Registry number: EC 3.4.21.47 (12 Dec 1998) |
| properdin factor d | <enzyme> A serum protein which during the alternate pathway of complement activation converts the inactive properdin factor b to c3 convertase. Registry number: EC 3.4.21.46 (12 Dec 1998) |
| properdin factor E | A serum protein (mw 160,000) required for activation of C3 (third component of complement) by cobra venom factor. See: properdin system. (05 Mar 2000) |
| scatter factor | A motility factor (motogen) isolated from conditioned medium in which human fibroblasts have been grown. It causes colonies of epithelial and endothelial cells, in culture, to separate into single cells that move apart i.e. They scatter. It has been shown to be identical to human hepatocyte growth factor, but it is not mitogenic for all cell types. (18 Nov 1997) |
| proteinase inhibitor inducing factor | See: PIIF. (18 Nov 1997) |
| protein factor | The factor (6.25) by which the nitrogen content of a protein is multiplied to give the amount of protein. (05 Mar 2000) |
| HG factor | A polypeptide hormone (3485 D) secreted by the cells of the Islets of Langerhans in response to a fall in blood sugar levels. Induces hyperglycaemia. A family of structurally related peptides includes glucagon like peptides 1 & 2 (encoded by the same gene), gastric inhibitory polypeptide, secretin, vasoactive intestinal peptide, growth hormone releasing factor, pituitary adenylate cyclase activating polypeptide, exendins. (18 Nov 1997) |
| x factor | <biochemistry> A precursor necessary to synthesise cytochromes. (09 Oct 1997) |
| psi factor | A protein responsible for the specific initiation of the RNA polymerase-catalyzed reaction at the promoter sites of genes. (05 Mar 2000) |
| secretor factor | <haematology> 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. (05 Mar 2000) |
| human antihemophilic factor | A lyophilised concentrate of factor VIII, obtained from fresh normal human plasma; used as a haemostatic agent in haemophilia. Synonym: antihemophilic globulin, human antihemophilic fraction. (05 Mar 2000) |