| hemoglobin | <cell biology, haematology> Four subunit globular oxygen carrying protein of the erythrocytes of vertebrates and some invertebrates. It is a conjugated protein containing four haem groups and globin. There are two alpha and two beta chains (very similar to myoglobin) in adult humans, the haem moiety (an iron containing substituted porphyrin) is firmly held in a nonpolar crevice in each peptide chain. There are four globin polypeptide chains, designated alpha, beta, gamma, delta in the adult. Each is composed of several hundred amino acids. (08 Mar 2000) |
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| angina pectoris, variant | A clinical syndrome characterised by development of chest pain at rest with concomitant transient st segment elevation in the electrocardiogram, but exercise capacity is well preserved. (12 Dec 1998) |
| variant | Something which differs in form from another thing, though really the same; as, a variant from a type in natural history; a variant of a story or a word. Origin: Cf. F. Variante. Source: Websters Dictionary (01 Mar 1998) |
| variant angina | A sudden vasoconstriction of a coronary artery depriving the myocardium of blood flow and oxygen. This may clinically manifest as chest pain referred to as variant angina or Printzmetal's angina. May be precipitated by emotional stress, medications, street drugs (cocaine) or on exposure to cold. Treatment includes nitroglycerin or beta-blocker medications. (27 Sep 1997) |
| variant angina pectoris | A form of angina pectoris, characterised by pain that is not precipitated by cardiac work, is of longer duration, is usually more severe, and is associated with unusual electrocardiographic manifestations including elevated ST segments in leads that are ordinarily depressed in typical angina, and usually without reciprocal ST changes; occurring at night in bed. Synonym: angina inversa, variant angina pectoris. (05 Mar 2000) |
| variant haemoglobin | A harmless mutant form of Hb. (05 Mar 2000) |
| variant surface glycoproteins, trypanosoma | Glycoproteins attached to the surface coat of the trypanosome. Many of these glycoproteins show amino acid sequence diversity expressed as antigenic variations. This continuous development of antigenically distinct variants in the course of infection ensures that some trypanosomes always survive the development of immune response to propagate the infection. (12 Dec 1998) |