| stem | The main stem or a branch of the main axial system of a plant, developed from the plumule of the embryo and typically bearing leaves. (09 Oct 1997) |
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| stem and loop structure | <molecular biology> The structure of tRNAs is so termed because it has four base paired stems and three loops (not base paired), one of which contains the anticodon. (18 Nov 1997) |
| stem bronchus | The main bronchus from which the branches of the bronchial tree arise. (05 Mar 2000) |
| stem cell | 1. Cell that gives rise to a lineage of cells. Particularly used to describe the most primitive cells in the bone marrow from which all the various types of blood cell are derived. 2. More commonly used of a cell that, upon division, produces dissimilar daughters, one replacing the original stem cell, the other differentiating further (e.g. Stem cells in basal layers of skin, in haematopoetic tissue and in meristems). (13 Nov 1997) |
| stem cell factor | <growth factor> Haemopoietic growth factor 18.6 kD from sequence, found as dimer (35 kD protein, 53 kD in its glycosylated form). Acronym: SCF (18 Nov 1997) |
| stem cell growth factors | <growth factor> Compounds, usually proteins, that make stem cells grow faster. (26 Mar 1998) |
| 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) |
| 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) |
| stemless | <botany> Having no stem; acaulescent. Source: Websters Dictionary (01 Mar 1998) |
| stemma | Origin: NL, fr. Gr, pl, a garland or chaplet. <zoology> One of the ocelli of an insect. See Ocellus. One of the facets of a compound eye of any arthropod. Source: Websters Dictionary (01 Mar 1998) |
| stemple | <chemical> A crossbar of wood in a shaft, serving as a step. Origin: G. Stempel a stamp, a prop, akin to E. Stamp. Source: Websters Dictionary (01 Mar 1998) |
| peripheral blood stem cell transplantation | A procedure that is similar to bone marrow transplantation. Doctors remove healthy immature cells (stem cells) from a patient's blood and store them before the patient receives high-dose chemotherapy and possibly radiation therapy to destroy the leukaemia cells. The stem cells are then returned to the patient, where they can produce new blood cells to replace cells destroyed by the treatment. (12 Dec 1998) |
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| pipe stem cirrhosis | Cirrhosis of the liver with finger-like fibrosis predominantly around portal tracts, seen in schistosomiasis. Leads to portal hypertension but rarely to functional failure of the liver. (05 Mar 2000) |
| pluripotent stem cell | <haematology> Cells in a stem cell line capable of differentiating into several different final differentiated types, for example there may be a pluripotent stem cell line for erythrocytes, granulocytes and megakaryocytes. (11 Mar 1998) |
| haematopoietic stem cell mobilization | The release of stem cells from the bone marrow into the peripheral blood circulation for the purpose of leukapheresis, prior to stem cell transplantion. Haematopoietic growth factors or chemotherapeutic agents often are used to stimulate the mobilization. (12 Dec 1998) |
| haematopoietic stem cells | Progenitor cells from which all blood cells derive. (12 Dec 1998) |
| haematopoietic stem cell transplantation | The transference of stem cells from one animal or human to another (allogeneic), or within the same individual (autologous). The source for the stem cells may be the bone marrow or peripheral blood. Stem cell transplantation has been used as an alternative to autologous bone marrow transplantation in the treatment of a variety of neoplasms. (12 Dec 1998) |
| haemopoietic stem cell | <haematology> Cell that gives rise to distinct daughter cells, one a replica of the stem cell, one a cell that will further proliferate and differentiate into a mature blood cell. Pluripotent stem cells can give rise to all lineages, committed stem cells (derived from the pluripotent stem cell) only to some. (18 Nov 1997) |
| hematopoietic stem cell | <haematology> Cell that gives rise to distinct daughter cells, one a replica of the stem cell, one a cell that will further proliferate and differentiate into a mature blood cell. Pluripotent stem cells can give rise to all lineages, committed stem cells (derived from the pluripotent stem cell) only to some. (18 Nov 1997) |
| 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) |