| arg | <oncogene> Oncogene, related to abl, that encodes a tyrosine kinase. (18 Nov 1997) |
|---|---|
| argala | <ornithology> The adjutant bird. Origin: Native name. Source: Websters Dictionary (01 Mar 1998) |
| argali | <zoology> A species of wild sheep (Ovis ammon, or O. Argali), remarkable for its large horns. It inhabits the mountains of Siberia and central Asia. The bearded argali is the aoudad. See Aoudad. The name is also applied to the bighorn sheep of the Rocky Mountains. See Bighorn. Origin: Mongolian. Source: Websters Dictionary (01 Mar 1998) |
| Argas | A genus of soft ticks of the family Argasidae, some species of which usually infest birds but may attack man. (05 Mar 2000) |
| Argas persicus | The abode, fowl, or Persian tick, a species that is a bloodsucking parasite of poultry; it transmits fowl spirochetosis. (05 Mar 2000) |
| Argas reflexus | The pigeon tick, a species that may cause a cutaneous inflammatory lesion in man. (05 Mar 2000) |
| argasid | Common name for members of the family Argasidae. (05 Mar 2000) |
| Argasidae | Family of ticks (superfamily Ixodoidea, order Acarina), the soft ticks, so called because of their wrinkled, leathery, tuberculated appearance that fills out when the tick is engorged with blood. A dorsal shield (scutum) is not present; the mouthparts (capitulum) are subterminal or ventral in a depression (camerostome) that extends above the capitulum to form the anterior margin of the cephalothorax (hood). Argasidae contains 4 genera: Argas, Ornithodoros, Otobius, and Antricola; argasid ticks, chiefly species of Ornithodoros, harbor and transmit spirochetes of the genus Borrelia that cause relapsing fever in birds and mammals. (05 Mar 2000) |
| argentaffin | Pertaining to cells or tissue elements that reduce silver ions in solution, thereby becoming stained brown or black. Origin: L. Argentum, silver, + affinitas, affinity (05 Mar 2000) |
| argentaffin cell | So called because they will form cytoplasmic deposits of metallic silver from silver salts. Their characteristic histochemical behaviour arises from 5 HT, which they secrete. Found chiefly in the epithelium of the gastrointestinal tract (though possibly of neural crest origin) their function is rather obscure, although there is a widely distributed family of such paracrine (local endocrine) cells (APUD cells). (18 Nov 1997) |
| argentaffin cells | Cell's that contain granules which precipitate silver from an ammoniacal silver nitrate solution. See: enteroendocrine cells. (05 Mar 2000) |
| argentaffin granules | Granule's that reduce silver ions from an ammoniacal silver nitrate staining solution. (05 Mar 2000) |
| argentaffinoma | <oncology, tumour> A tumour which secretes excessive amounts of the hormone serotonin. The clinical result is carcinoid syndrome. These tumours may grow anywhere in the gastrointestinal tract (and in the lungs) with approximately 90% in the appendix. The remainder occur in the ileum, stomach, colon or rectum. (27 Sep 1997) |
| argentate | <botany> Silvery white. Origin: L. Argentatus silvered. Source: Websters Dictionary (01 Mar 1998) |
| argentation | Impregnation with a silver salt. See: argyria. Origin: L. Argentum, silver (05 Mar 2000) |
| RNA, transfer, arg | A transfer RNA which is specific for carrying arginine to sites on the ribosomes in preparation for protein synthesis. (12 Dec 1998) |
|---|