| B-cell | <haematology, immunology> A type of lymphocyte normally involved in the production of antibodies to combat infection. It is a precursor to a plasma cell. During infections, individual B-cell clones multiply and are transformed into plasma cells, which produce large amounts of antibodies against a particular antigen on a foreign microbe. This transformation occurs through interaction with the appropriate CD4 T-helper cells. (09 Oct 1997) |
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| B-cell antigen receptors | In the primary immune response immunoglobulin D and monomeric immunoglobulin M are the B-cell antigen receptors. On memory B-cells, other immunoglobulin molecules can serve as antigen receptors. (05 Mar 2000) |
| B-cell differentiating factor | <cytokine> A soluble cytokine factor produced by activated T-lymphocytes that promotes antibody production by causing proliferation and differentiation of B-cells. Interleukin-4 induces the expression of class II major histocompatibility complex and fc receptors on B-cells. It also acts on T-lymphocytes, mast cell lines, and several other haematopoietic lineage cells including granulocyte, megakaryocyte, and erythroid precursors, as well as macrophages. Acronym: IL-4 (12 Dec 1998) |
| B-cell differentiation/growth factors | Various substances, usually obtained from the supernatant of T-cell cultures, such as interleukin 4, 5, and 6. These substances are necessary for B-cell growth, maturation, and differentiation into plasma cells or B memory cells. (05 Mar 2000) |
| B-cell leukaemia | A test which detects the presence of antigens on the surface of B lymphocytes. These antigens can indicate the presence of leukaemia. most often this is used to detect and differentiate chronic lymphocytic leukaemia from acute lymphocytic leukaemia. Origin: Gr. Haima = blood (27 Sep 1997) |
| B-cell stimulatory factor 2 | <cytokine> A cytokine that stimulates the growth and differentiation of human B-cells and is also a growth factor for hybridomas and plasmacytomas. It is produced by many different cells including T-cells, monocytes, and fibroblasts. A single chain 25 kD cytokine originally described as a pre B-cell growth factor, now known to have effects on a number of other cells including T-cells which are also stimulated to proliferate. An inducer of acute phase proteins and a colony-stimulating factor acting on mouse bone marrow. Acronym: IL-6 (12 Dec 1998) |
| beaker cell | 1. <pathology> Cell of the epithelial lining of small intestine that secretes mucus and has a very well developed Golgi apparatus. 2. <zoology> Cell type characteristic of larval lepidopteran midgut, containing a potent H ATPase and thought to be involved in maintenance of ion and pH gradients. (10 Oct 1997) |
| Beale's cell | A bipolar ganglion cell of the heart with one spiral and one straight prolongation. (05 Mar 2000) |
| berry cell | A crenated red blood cell with surface spicules. (05 Mar 2000) |
| beta cell | 1. <pathology> Cells of the pancreas within discrete endocrine islands (Islets of Langerhans) embedded in the major exocrine tissue of vertebrate pancreas. The B or beta cells (originally distinguished by differential staining from A, C and D), are responsible for synthesis and secretion of insulin, a hormone that controls the level of glucosein the blood. 2. Also refers to the beta cells of the anterior lobe of hypophysis. These are a population of functionally diverse cell's that contain basophilic granules and secrete hormones such as ACTH, lipotropin, thyrotropin, and the gonadotropins. Synonym: basophil cell of anterior lobe of hypophysis. (05 Mar 2000) |
| beta-cell src-homology tyrosine kinase | <enzyme> A murine frk (fyn-related kinase) homolog; genbank l36132; do not confuse with brain-specific kinase bsk Registry number: EC 2.7.1.- Synonym: beta-cell sh tk, bsk protein, sh tk, bsk gene product, sh tk (26 Jun 1999) |
| betz cell | Large pyramidal cells in the motor cortex of the precentral gyrus of the motor cortex. (27 Sep 1997) |
| BHK cell | <cell culture> A quasi diploid established line of Syrian hamster cells, descended from a clone (Clone 13) isolated by Stoker and McPherson from an unusually rapidly growing primary culture of new born hamster kidney tissue. Usually described as fibroblastic, although smooth muscle like in that they express the muscle intermediate filament protein desmin. Widely used as a viral host, in studies of oncogenic transformation and of cell physiology. (18 Nov 1997) |
| bipolar cell | <cell biology, physiology> A class of retinal interneurons, named after their morphology, that receive input from the photoreceptors and send it to the ganglion cells. Bipolar cells are nonspiking, their response to light is evenly graded and shows lateral inhibition. (19 Jan 1998) |
| blast cell | <haematology> A immature cell of a proliferative compartment in a cell lineage that normally represent up to 5% of the cells in the bone marrow. An over-production of blasts in the marrow is characteristic of leukaemia when the blast cells often spill out into the blood stream. (17 Mar 1998) |