| onchocerciasis | Infection with nematodes of the genus onchocerca. Characteristics include the presence of firm subcutaneous nodules filled with adult worms, pruritus, and ocular lesions. (12 Dec 1998) |
|---|---|
| onchocerciasis, ocular | Filarial infection of the eyes transmitted from person to person by bites of onchocerca volvulus-infected black flies. The microfilariae of onchocerca are thus deposited beneath the skin. They migrate through various tissues including the eye. Those persons infected have impaired vision and up to 20% are blind. The incidence of eye lesions has been reported to be as high as 30% in central america and parts of africa. (12 Dec 1998) |
| onchocercid | Common name for members of the family Onchocercidae. (05 Mar 2000) |
| Onchocercidae | A family of nematode parasites (superfamily Filarioidea) characterised by production of microfilariae; it includes the genera Onchocerca, Wuchereria, Brugia, Loa, and Mansonella. (05 Mar 2000) |
| onchocercosis | Infection with nematodes of the genus onchocerca. Characteristics include the presence of firm subcutaneous nodules filled with adult worms, pruritus, and ocular lesions. (12 Dec 1998) |
| oncidium | <botany> A genus of tropical orchidaceous plants, the flower of one species of which (O. Papilio) resembles a butterfly. Source: Websters Dictionary (01 Mar 1998) |
| onco | <prefix> Prefix meaning tumour or the process of cancer formation. Origin: G. Onkos, bulk, mass (21 Jun 2000) |
| Oncocerca | A genus of parasitic nematodes whose organisms live and breed in skin and subcutaneous tissues. Onchocercal microfilariae may also be found in the urine, blood, or sputum. (12 Dec 1998) |
| oncocyte | Askenazy cell |
| oncocytic hepatocellular tumour | <tumour> Primary hepatic carcinoma in which malignant hepatocytes are intersected by fibrous lamellated bands. Synonym: oncocytic hepatocellular tumour. (05 Mar 2000) |
| oncocytoma | <tumour> A glandular tumour composed of large cells with cytoplasm that is granular and eosinophilic due to the presence of abundant mitochondria; occurs uncommonly in the kidney, salivary glands, and endocrine glands. Synonym: oxyphil adenoma. Origin: onco-+ G. Kytos, cell, + -oma, tumour (05 Mar 2000) |
| oncofetal | Relating to tumour-associated substances present in foetal tissue, as oncofetal antigens. (05 Mar 2000) |
| oncofetal antigens | Tumour-associated antigen's present in foetal tissue but not in normal adult tissue, including alpha-fetoprotein and carcinoembryonic antigen. (05 Mar 2000) |
| oncofetal marker | A tumour marker produced by tumour tissue and by foetal tissue of the same type as the tumour, but not by normal adult tissue from which the tumour arises. (05 Mar 2000) |
| oncogen | <oncology, pharmacology> Synonym for carcinogen, an agent causing cancer. (18 Nov 1997) |