| stem cell leukaemia | A form of leukaemia in which the abnormal cells are thought to be the precursors of lymphoblasts, myeloblasts, or monoblasts. Synonym: embryonal leukaemia. (05 Mar 2000) |
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| stem cells | Relatively undifferentiated cells of the same lineage (family type) that retain the ability to divide and cycle throughout postnatal life to provide cells that can become specialised and take the place of those that die or are lost. (12 Dec 1998) |
| stem-clasping | <botany> Embracing the stem with its base; amplexicaul; as a leaf or petiole. Source: Websters Dictionary (01 Mar 1998) |
| quiescent stem cell | A stem cell that is not at that time undergoing repeated cell cycles but that might be stimulated so to do later. For example: the satellite cells in the skeletal muscles of mammals that are quiescent myoblasts that will proliferate after wounding and give rise to more muscle cells by fusion. (18 Nov 1997) |
| infundibular stem | The neural component of the pituitary stalk that contains nerve tracts passing from the hypothalamus to the pars nervosa. Synonym: infundibular stalk. (05 Mar 2000) |
| tumour stem cell assay | <investigation> A cytologic technique for measuring the functional capacity of tumour stem cells by assaying their activity. It is used primarily for the in vitro testing of antineoplastic agent. (12 Dec 1998) |
| tumour stem cells | <cell biology> Colony-forming cells which give rise to neoplasms. (12 Dec 1998) |
| abnormal cleavage of cardiac valve | Congenital malformation of a valve leaflet with a defect extending from the free margin. (05 Mar 2000) |
| Amussat's valve | A series of crescentic folds of mucous membrane in the upper part of the cystic duct, arranged in a somewhat spiral manner. Synonym: plica spiralis ductus cystici, Amussat's valve, Heister's valve, spiral valve of cystic duct, valvula spiralis. (05 Mar 2000) |
| anterior cusp of atrioventricular valve | The anterior leaflet or valvule of either the tricuspid or mitral valves. Synonym: cuspis anterior valvae atrioventricularis dextrae/sinistrae. (05 Mar 2000) |
| anterior urethral valve | A crescentic horizontal fold in the proximal spongy urethra. (05 Mar 2000) |
| aortic valve | The heart valve that divides the left ventricle and the aorta. The aortic valve opens during left ventricular contraction and then closes to prohibit the backwash of oxygenated blood from the aorta into the ventricle. The aortic valve has 3 valve cusps. (27 Sep 1997) |
| aortic valve insufficiency | Backflow of blood from the aorta into the left ventricle, owing to imperfect functioning of the aortic semilunar valve. (12 Dec 1998) |
| aortic valve prolapse | The downward displacement of the cuspal material (misalignment of the cusps) below a line joining points of attachment of the aortic valve leaflets. The prolapsed cusp may occlude the ventricular septal defect during ventricular diastole. (12 Dec 1998) |
| aortic valve stenosis | Narrowing of the orifice of the aortic valve or of the supravalular or subvalvular regions. (12 Dec 1998) |