| initiation factors | The set of catalytic proteins required, in addition to mRNA and ribosomes, for protein synthesis to begin. In bacteria three distinct proteins have been identified: if 1 (8 kD), IF 2 (75 kD) and IF 3 (30 kD). at least 6-8 proteins have been identified in eukaryotes. IFs 1 and 2 enhance the binding of initiator tRNA to the initiation complex. (18 Nov 1997) |
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| insulin-like growth factors | 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. Synonym: somatomedins. (05 Mar 2000) |
| ischemia-modifying factors | 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. (05 Mar 2000) |
| oesophageal carcinoma risk factors | <radiology> P Plummer-Vinson Web, A achalasia, alcohol, B Barrett oesophagus, S stricture, T tylosis, tobacco see: oesophageal carcinoma (12 Dec 1998) |
| thyroid carcinoma risk factors | <radiology> Increased risk of malignancy: young female, male, history of radiation to head or neck, hard lesion, other neck masses, no shrinkage on TSH, family hx of thyroid carcinoma see: thyroid carcinoma (12 Dec 1998) |
| time factors | Elements of limited time intervals, contributing to particular results or situations. (12 Dec 1998) |
| transcription factors | Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process. (12 Dec 1998) |
| transcription factors, tfii | The so-called general transcription factors that bind to RNA polymerase II and that are required to initiate transcription. They include tfiia, tfiib, tfiid, tfiie, tfiif, tfiih, tfii-I, and tfiij. In vivo they apparently bind in an ordered multi-step process and/or may form a large preinitiation complex called RNA polymerase II holoenzyme. (12 Dec 1998) |
| transcription factors, tfiii | Factors that bind to RNA polymerase III and aid in transcription. They include the assembly factors tfiiia and tfiiic and the initiation factor tfiiib. All combine to form a preinitiation complex at the promotor that directs the binding of RNA polymerase III. (12 Dec 1998) |
| transforming growth factors | <chemical> Hormonally active polypeptides that can induce the transformed phenotype when added to normal, non-transformed cells. They have been found in culture fluids from retrovirally transformed cells and in tumour-derived cells as well as in non-neoplastic sources. Their transforming activities are due to the simultaneous action of two otherwise unrelated factors, transforming growth factor alpha and transforming growth factor beta. Chemical name: Animal growth regulators, transforming growth factors (12 Dec 1998) |
| endothelial growth factors | These growth factors are soluble mitogens secreted by a variety of organs. The factors are a mixture of two single chain polypeptides which have affinity to heparin. Their molecular weight are organ and species dependent. They have mitogenic and chemotactic effects and can stimulate endothelial cells to grow and synthesise DNA. The factors are related to both the basic and acidic fibroblast growth factors but have different amino acid sequences. (12 Dec 1998) |
| epidemiologic factors | Events, characteristics, or other definable entities that have the potential to bring about a change in a health condition or other defined outcome. (12 Dec 1998) |
| essential food factors | Those substances required in the diet: certain amino acids and unsaturated fatty acids, vitamins, essential minerals, etc. (05 Mar 2000) |
| Factors I XII | <haematology> Blood clotting factors, especially from humans. These factors form a cascade in which the activation of the first factor leads to enzymic attack on the next factor and so on, finally resulting in blood clotting. (18 Nov 1997) |
| uncoupling factors | Substances such as dinitrophenol that allow oxidation in mitochondria to proceed without the usual concomitant phosphorylation to produce ATP; these poisons thus "uncouple" oxidation and phosphorylation. Synonym: uncoupling factors. (05 Mar 2000) |