| CD4 cell count | The most commonly used surrogate marker for assessing the state of the immune system. As CD4 cell count declines, the risk of developing opportunistic infections increases. The normal range for CD4 cell counts is 500 to 1500 per cubic millimetre of blood. CD4 count should be rechecked at least every six to twelve months if CD4s are greater than 500/mm3. If the count is lower, testing every three months is advised. (09 Oct 1997) |
|---|---|
| virus-transformed cell | A cell that has been genetically changed to a tumour cell, the change being subsequently tramsmitted to all descendent cell's; cell's transformed by oncornaviruses continue to produce virus in high concentration without being killed; DNA tumour virus-transformed cell's develop (along with other changes) tumour-associated antigens and rarely produce virus. (05 Mar 2000) |
| CD8 cell | <immunology> One type of T-lymphocyte which bears the CD8 molecular marker on its surface. Some CD8 cells recognise and kill cancerous cells and those infected by intracellular pathogens (some bacteria, viruses and mycoplasma). These cells are called cytotoxic T-lymphocytes (see). (09 Oct 1997) |
| glomerulosa cell | A cell of the zona glomerulosa of the adrenal cortex that is the source of aldosterone; the cell's are arranged in spherical or oval groups. (05 Mar 2000) |
| cell | <cell biology> An autonomous self replicating unit (in principle) that may constitute an organism (in the case of unicellular organisms) or be a sub unit of multicellular organisms in which individual cells may be more or less specialised differentiated) for particular functions. The individual units from which tissues of the body are formed. All living organisms are composed of one or more cells. (26 Mar 1998) |
| cell adhesion | See: adhesins, cadherins, cell adhesion molecules (CAMs), contact sites A, DLVO theory, integrins, sorting out, uvomorulin and various specialised junctions (adherens junctions, desmosomes, focal adhesions, gap junction and zonula occludens). (18 Nov 1997) |
| cell adhesion kinase | <enzyme> From hela cells; involved in cell-cell interactions; genbank l20817 Registry number: EC 2.7.1.- Synonym: cak protein (26 Jun 1999) |
| cell adhesion molecule | <molecular biology> Although this could mean any molecule involved in cellular adhesive phenomena, it has acquired a more restricted sense, namely a molecule on the surface of animal tissue cells, antibodies (or Fab fragments) against that specifically inhibit some form of intercellular adhesion. Examples are Liver Cell Adhesion Molecule and Neural Cell Adhesion Molecule, both named from tissues in which first detected, although their occurrence is not in fact restricted to these. Acronym: CAM (26 Nov 1998) |
| cell adhesion molecules | Surface ligands, usually glycoproteins, that mediate cell-to-cell adhesion. Their functions include the assembly and interconnection of various vertebrate systems, as well as maintenance of tissue integration, wound healing, morphogenic movements, cellular migrations, and metastasis. (12 Dec 1998) |
| cell adhesion molecules, neuronal | Surface ligands that mediate cell-to-cell adhesion and function in the assembly and interconnection of the vertebrate nervous system. These molecules promote cell adhesion via a homophilic mechanism. These are not to be confused with ncam (neural cell adhesion molecule), now known to be expressed in a variety of tissues and cell types in addition to nervous tissue. (12 Dec 1998) |
| cell adhesion molecules, neuron-glia | Cell adhesion molecules that mediate neuron-neuron adhesion and neuron-astrocyte adhesion. They are expressed on neurons and schwann cells, but not astrocytes and are involved in neuronal migration, neurite fasciculation, and outgrowth. Ng-cam is immunologically and structurally distinct from ncam (neural cell adhesion molecules). (12 Dec 1998) |
| cell aggregation | The phenomenon by which dissociated cells intermixed in vitro tend to group themselves with cells of their own type. (12 Dec 1998) |
| cell aging | The decrease in the cell's ability to proliferate with the passing of time. Each cell is programmed for a certain number of cell divisions and at the end of that time proliferation halts. The cell enters a quiescent state after which it experiences cell death via the process of apoptosis. (12 Dec 1998) |
| cell behaviour | <cell biology> General term for activities of whole cells such as movement, adhesion and proliferation, by analogy with animal behaviour. (18 Nov 1997) |
| cell biology | <study> The study of the internal workings of cells at the microscopic and molecular level - it is closely linked to molecular biology. (16 Dec 1997) |