| optical activity | The ability of a material to rotate the plane of polarized light. (09 Oct 1997) |
|---|---|
| triggered activity | One or a series of spontaneously generated heart beats originating from an action potential that produces an after-depolarisation which reaches activation threshold. (05 Mar 2000) |
| unit of thyrotrophic activity | The activity of an amount of an extract of the anterior lobe of the hypophysis which, given daily for 5 days, will cause the thyroid of a guinea pig (weighing 200 g) to reach a weight of 600 mg. (05 Mar 2000) |
| zone of polarizing activity | <cell biology> The small group of mesenchyme cells in avian limb buds that is located at the posterior margin of the developing bud and that produces a substance, possibly retinoic acid, that provides positional information to the developing limb bud. (18 Nov 1997) |
| Galton's delta | A more or less well-marked triangle, in a fingerprint, on either side where the straight ridges near the joint of the distal phalanx are succeeded by arches, loops, or whorls. See: Galton's system of classification of fingerprints. Synonym: triradius. (05 Mar 2000) |
| gene rearrangement, delta-chain T-cell antigen receptor | Ordered rearrangement of T-cell variable gene regions coding for the delta-chain of antigen receptors. (12 Dec 1998) |
| genes, T-cell receptor delta | DNA sequences encoding the delta chain of the T-cell receptor. The delta-chain locus is located entirely within the alpha-chain locus. (12 Dec 1998) |
| receptors, antigen, T-cell, gamma-delta | T-cell receptors composed of CD3-associated gamma and delta polypeptide chains and expressed primarily in CD4-/CD8- T-cells. The receptors appear to be preferentially located in epithelial sites and probably play a role in the recognition of bacterial antigens. The T-cell receptor gamma/delta chains are separate and not related to the gamma and delta chains which are subunits of CD3 (see antigens, CD3). (12 Dec 1998) |
| receptors, opioid, delta | A class of opioid receptors recognised by its pharmacological profile. Delta opioid receptors bind endorphins and enkephalins with approximately equal affinity and have less affinity for dynorphins. (12 Dec 1998) |
| CDP-6-deoxy-delta(3,4)-glucoseen reductase | <enzyme> Key enzyme catalyzing the biosynthetic formation of cdp-ascarylose via a pyridoxamine-linked intermediate; the enzyme can also oxidise NADPH in the presence of oxygen; from yerisinia pseudotuberculosis Registry number: EC 1.17.1.- Synonym: cddg reductase (26 Jun 1999) |
| muconolactone delta-isomerase | <enzyme> Catalyses the conversion of 4-hydroxy-4-carboxymethylisocrotonolactone to 3-oxoadipate enol-lactone; minor descriptor (75-83); on-line and index medicus search isomerases (75-83) Registry number: EC 5.3.3.4 (26 Jun 1999) |
| cortisol delta 4-reductase | <enzyme> Forms 5 alpha-dihydrocortisol& 5 beta-dihydrocortisol Registry number: EC 1.3.1.- Synonym: cortisol delta(4)-hydrogenase, cortisol delta(4)-5 beta-reductase (26 Jun 1999) |
| cucurbitacin delta 23-reductase | <enzyme> Catalyses the oxidation of 23,24-dihydrocucurbitacin to cucurbitacin in the presence of NADP+ Registry number: EC 1.3.1.5 (26 Jun 1999) |
| hepatitis delta | <virology> Hepatitis delta is a severe form of hepatitis which arose recently. It is caused by a combination of the delta virus (a defective virus) and the virus which causes hepatitis B. (09 Oct 1997) |
| hepatitis delta virus | A defective virus, containing particles of RNA nucleoprotein in virion-like form, present in patients with acute hepatitis b and chronic hepatitis. Officially this is classified as a subviral satellite RNA (RNA, satellite). (12 Dec 1998) |