| macronutrients | Nutrients required in the greatest amount; e.g., carbohydrates, protein, fats. (05 Mar 2000) |
|---|---|
| macronychia | Abnormally large fingernails or toenails. Synonym: megalonychosis. Origin: macro-+ G. Onyx, nail (05 Mar 2000) |
| macroorchidism | Having abnormally large testes; seen in males with fragile X syndrome. Origin: macro-+ G. Orchis (orchid-), testicle (05 Mar 2000) |
| macroparasite | A parasite, such as a louse or an intestinal worm, that is visible to the naked eye. (05 Mar 2000) |
| macroparasites | <epidemiology> Typically, the parasitic helminths and arthropods. In general, parasites which do not multiply within their definitive hosts but instead produce transmission stages (eggs and larvae) which pass into the external environment. Immune responses elicited against macroparasites generally depend on the number of parasites present in a given host and tends to be of a relatively transient nature. The key epidemiological measurement is generally the number of parasites per host. Such parasites are often found in a highly aggregated distribution. Contrast microparasites. (05 Dec 1998) |
| macropathology | The phase of pathology that pertains to the gross anatomical changes in disease. (05 Mar 2000) |
| macropenis | An abnormally large penis. Synonym: macrophallus. (05 Mar 2000) |
| macropetalous | <botany> Having long or large petals. Origin: Macro- + petal. Source: Websters Dictionary (01 Mar 1998) |
| macrophage | Relatively long lived phagocytic cell of mammalian tissues, derived from blood monocyte. Macrophages from different sites have distinctly different properties. Main types are peritoneal and alveolar macrophages, tissue macrophages (histiocytes), Kupffer cells of the liver and osteoclasts. In response to foreign materials may become stimulated or activated. Macrophages play an important role in killing of some bacteria, protozoa and tumour cells, release substances that stimulate other cells of the immune system and are involved in antigen presentation. May further differentiate within chronic inflammatory lesions to epithelioid cells or may fuse to form foreign body giant cells or Langhans giant cells. (18 Nov 1997) |
| macrophage activation | The process of altering the morphology and functional activity of macrophages so that they become avidly phagocytic. It is initiated by lymphokines, such as the macrophage activation factor (maf) and the macrophage migration-inhibitory factor (mmif), immune complexes, c3b, and various peptides, polysaccharides, and immunologic adjuvants. (12 Dec 1998) |
| macrophage colony-stimulating factor | <growth factor> A glycoprotein growth factor that causes the committed cell line to proliferate and mature into macrophages. A cytokine synthesised by mesenchymal cells that stimulates pluripotent stem cells of bone marrow into differentiating towards the production of monocytes (mononuclear phagocytes). The compound stimulates the survival, proliferation, and differentiation of haematopoietic cells of the monocyte-macrophage series. It is a disulfide-bonded glycoprotein dimer with a mw of 70 kD and binds to a single class of high affinity receptor which is identical to the product of the c-fms proto-oncogene. See: colony-stimulating factors. Chemical name: Colony-stimulating factor 1 Acronym: M-CSF (12 Dec 1998) |
| macrophage inflammatory protein | <cytokine> A chemokine that is chemotactic for neutrophils and monocytes, stimulates macrophages, and may play a role in regulating haematopoiesis. Its two variants, mip-1alpha and mip-1beta, are 60% homologous to each other. They are heparin-binding proteins that exhibit a number of inflammatory and immunoregulatory activities. Originally identified as secretory products of macrophages, these chemokines are produced by a variety of cell types including neutrophils, fibroblasts, and epithelial cells. They most likely also play a significant role in respiratory tract defenses. (20 Sep 2002) |
| macrophage inhibition factor | <cytokine> A group of lymphokines (including a 14 kD glycoprotein) produced by activated T lymphocytes that reduces macrophage mobility and probably increases macrophage macrophage adhesion. (18 Nov 1997) |
| macrophage migration inhibition test | A test which measures the presence of migration-inhibitory factor. Usually peritoneal macrophages are placed in a capillary tube in the presence or absence of supernatants from activated T-cells. If MIF is present, the migration of monocyte/macrophages is reduced. Synonym: macrophage migration inhibition test, migration inhibition test. (05 Mar 2000) |
| macrophage migration-inhibitory factors | Proteins released by sensitised lymphocytes and possibly other cells that inhibit the migration of macrophages away from the release site. The structure and chemical properties may vary with the species and type of releasing cell. (12 Dec 1998) |