| 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) |
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| antigens, CD8 | <immunology> Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. Cd8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in major histocompatibility complex class I-restricted interactions. (12 Dec 1998) |
| CD4/CD8 count | The ratio of the number of helper-inducer T lymphocytes to cytotoxic-suppressor T lymphocytes, as measured by monoclonal antibodies to the CD4 surface antigen found on helper-inducer T-cells, and the CD8 surface antigen found on cytotoxic-suppressor T-cells. In healthy individuals, the H/S ratio ranges between 1.6 and 2.2.When the body mounts an immune response, as against a virus or a transplant, the ratio is almost always reduced because of a decrease in the number of circulating helper-inducer cells and an increase in suppressor cells. The CD4/CD8 count has been used to monitor for signs of organ rejection after transplants, and more recently has become a tool for assessing the relative condition of HIV patients. With the CD4 absolute count and the CD4 lymphocyte percentage, it provides a way of gauging the progression from HIV to AIDS. (05 Mar 2000) |
| CD4:CD8 ratio | The ratio of CD4 to CD8 cells. A common measure of immune system status that is around two in healthy individuals. The ratio of T-lymphocytes that express the CD4 antigen to those that express the CD8 antigen. This value is commonly assessed in the diagnosis and staging of diseases affecting the immune system including HIV infection. (12 Dec 1998) |
| CD8 | <immunology> Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. Cd8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in major histocompatibility complex class I-restricted interactions. (12 Dec 1998) |
| CD8-positive T-lymphocytes | A critical subpopulation of regulatory T-lymphocytes involved in MHC class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-lymphocytes, cytotoxic) and suppressor T-lymphocytes (T-lymphocytes, suppressor-effector). (12 Dec 1998) |
| T-cell-rich, B-cell lymphoma | <tumour> A B-cell lymphoma in which more than 90% of the cells are of T-cell origin, masking the large cells that form the neoplastic B-cell component. See: adult T-cell lymphoma. (05 Mar 2000) |
| absorption cell | A small glass chamber with parallel sides, in which absorption spectra of solutions can be obtained. (05 Mar 2000) |
| acid cell | One of the cell's of the gastric glands; it lies upon the basement membrane, covered by the chief cell's, and secretes hydrochloric acid that reaches the lumen of the gland through fine intracellular and intercellular canals (canaliculi). Synonym: acid cell, oxyntic cell. (05 Mar 2000) |
| acidophil cell | A cell whose cytoplasm or its granules stain with acid dyes. (05 Mar 2000) |
| acinar cell | Any secreting cell lining an acinus, especially applied to the cell's of the pancreas that furnish pancreatic juice and enzymes to distinguish them from the cell's of ducts and the islets of Langerhans. Synonym: acinous cell. (05 Mar 2000) |
| acinar cell tumour | A solid and cystic tumour of the pancreas, occurring in young women; tumour cells contain zymogen granules. (05 Mar 2000) |
| acinic cell adenocarcinoma | <tumour> An adenocarcinoma arising from secreting cells of a racemose gland, particularly the salivary glands. Synonym: acinar carcinoma, acinic cell carcinoma, acinose carcinoma, acinous carcinoma. (05 Mar 2000) |
| acinic cell carcinoma | <tumour> An adenocarcinoma arising from secreting cells of a racemose gland, particularly the salivary glands. Synonym: acinar carcinoma, acinic cell carcinoma, acinose carcinoma, acinous carcinoma. (05 Mar 2000) |
| acinous cell | Any secreting cell lining an acinus, especially applied to the cell's of the pancreas that furnish pancreatic juice and enzymes to distinguish them from the cell's of ducts and the islets of Langerhans. Synonym: acinous cell. (05 Mar 2000) |