| Nat | native; natural |
|---|---|
| NCMC | natural cell-mediated cytotoxicity |
| ND | Doctor of Naturopathy; nasal deformity; natural death; Naval Dispensary; neonatal death; neoplastic ... |
| NK | Commission on [Anatomical] Nomenclature [Ger. Nomenklatur Kommission]; natural killer [cell]; neurok... |
| NKCA | natural killer cell activity |
| natural mutation | A mutation which occurs by itself without first being affected by a mutagen, for example during the process of DNA replication. Spontaneous mutations arise at a remarkably constant rate. The rate that spontaneous mutations arise has been used as an evolutionary clock to estimate how closely related two (or more) separate species are to each other. (09 Oct 1997) |
|---|---|
| natural passive immunity | Immunity conferred by the mother on the foetus or newborn. (14 Nov 1997) |
| natural pigment | A naturally occurring coloured compound; absorbs light in the visible range of the electromagnetic spectrum. Compare: structural colour. Synonym: biochrome. (05 Mar 2000) |
| natural products | Naturally occurring compounds that are end products of secondary metabolism; often, they are unique compounds for particular organisms or classes of organisms. (05 Mar 2000) |
| natural selection | The hypothesis that genotype environment interactions occurring at the phenotypic level lead to differential reproductive success of individuals and hence to modification of the gene pool of a population. (18 Nov 1997) |
| immunity, natural | The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from non-specific mechanisms such as genetic endowment, naturally occurring antiviral and bactericidal substances, phagocytosis, and constitutional factors such as body temperature, oxygen tension, and age. (12 Dec 1998) |
| killer cells, natural | Cells responsible for spontaneous cytotoxicity of a variety of tumour cells without prior immunization. These natural killer cells are found in non-immune humans and experimental animals and are thought by some to be the same as killer cells (killing by antibody-dependent cell cytotoxicity), but they can also kill in the absence of antibody. (12 Dec 1998) |
| administration, oral | The giving of drugs, chemicals, or other substances by mouth. (12 Dec 1998) |
| cancer, oral | Cancer of the mouth area. A sore in the mouth that does not heal can be a warning sign of oral cancer. A biopsy is the only to know whether as abnormal area in the oral cavity is cancer. Oral cancer is caused by tobacco (smoking and chewing) and alcohol use. Surgery to remove the tumour in the mouth is the usual treatment for patients with oral cancer. (12 Dec 1998) |
| candidiasis, oral | Infection of the mucous membranes of the mouth by a fungus of the genus candida. (12 Dec 1998) |
| canine oral papilloma | Warts affecting mucous membranes of young dogs; caused by a papillomavirus. (05 Mar 2000) |
| magnesia and alumina oral suspension | A mixture of magnesium hydroxide and variable amounts of aluminum oxide; used as an antacid. (05 Mar 2000) |
| pathology, oral | A dental specialty concerned with pathology of the oral cavity. (12 Dec 1998) |
| pharyngo-oral | Relating to the pharynx and the mouth; oropharyngeal. Origin: pharyngo-+ L. Os (or-), mouth (05 Mar 2000) |
| combination oral contraceptive | A mixture of a steroid having progestational activity and an oestrogen. (05 Mar 2000) |