| balloon cell | An unusually large degenerated cell with pale-staining vacuolated or reticulated cytoplasm, as in viral hepatitis or in degenerated epidermal cell's in herpes zoster, a large form of nevus cell with abundant nonstaining cytoplasm, formed by vacular degeneration of melanosomes. (05 Mar 2000) |
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| balloon cell nevus | A nevus in which many of the cells are large, with clear cytoplasm. (05 Mar 2000) |
| band cell | <pathology> Immature neutrophils released from the bone marrow reserve in response to acute demand. (18 Nov 1997) |
| b and t cell count | A test that measures the respective quantities of B lymphocytes and T lymphocytes. This test is often performed in the analysis of an immune deficiency disorder. Normal values include: 68 to 75% of total lymphocytes are T lymphocytes and 10 to 20% are B lymphocytes. Increased T-cell counts can indicate infectious mononucleosis, acute lymphocytic leukaemia or multiple myeloma. Increased B lymphocytes can indicate chronic lymphocytic leukaemia, multiple myeloma, Waldenstrom's macroglobulinaemia or Di George syndrome. Decreased T-cells may indicate congenital T-cell deficiency, Wiskott-Aldrich syndrome or AIDS. Decreased B-cells may indicate acute lymphocytic leukaemia or a congenital immunoglobulin deficiency disorder. (27 Sep 1997) |
| basaloid cell | A cell, usually of the epidermis, resembling a basal cell. (05 Mar 2000) |
| basilar cell | <pathology> General term for relatively undifferentiated cells in an epithelial sheet that give rise to more specialised cells act as stem cells). In the stratified squamous epithelium of mammalian skin the basal cells of the epidermis (stratum basale) give rise by an unequal division to another basal cell and to cells that progress through the spinous, granular and horny layers, becoming progressively more keratinised, the outermost being shed as squames. In olfactory mucosa the basal cells give rise to olfactory and sustentacular cells. In the epithelium of epididymis their function is unclear, but they probably serve as stem cells. (13 Nov 1997) |
| basket cell | Cerebellar neurons with many small dendritic branches that enclose the cell bodies of adjacent Purkinje cells in a basket like array. (18 Nov 1997) |
| basophil cell of anterior lobe of hypophysis | beta cell of anterior lobe of hypophysis |
| 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) |
| 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) |