| nephelometry and turbidimetry | Chemical analysis based on the phenomenon whereby light, passing through a medium with dispersed particles of a different refractive index from that of the medium, is attenuated in intensity by scattering. In turbidimetry, the intensity of light transmitted through the medium, the unscattered light, is measured. In nephelometry, the intensity of the scattered light is measured, usually, but not necessarily, at right angles to the incident light beam. (12 Dec 1998) |
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| neuropathies, hereditary motor and sensory | A group of slowly progressive inherited disorders in which the predominant involvement is the peripheral motor neurons with lesser involvement of the peripheral sensory neurons. Neuronal degeneration and atrophy are characteristic of these disorders. Some of the associated characteristics are phytanic acid excess, optic atrophy, and retinitis pigmentosa. (12 Dec 1998) |
| neuropathies, hereditary sensory and autonomic | A group of inherited disorders in which there is selective involvement of the peripheral sensory and autonomic neurons and degeneration of fibres by axonal atrophy and degeneration. Five types of disorders have been described and classified type I through type v. (12 Dec 1998) |
| neurotransmitters and neurotransmitter agents | A collective grouping for neurotransmitters and substances that act on the neurotransmitter system. (12 Dec 1998) |
| streptodornase and streptokinase | <enzyme> A mixture of the enzymes (streptokinase and streptodornase) produced by haemolytic streptococci. It is used topically on surface lesions and by instillation in closed body cavities to remove clotted blood or fibrinous or purulent accumulations. It is also used as a skin test antigen in evaluating generalised cell-mediated immunodeficiency. Registry number: EC 3.- (12 Dec 1998) |
| nevi and melanomas | A collective term for the various types of nevi and melanomas. (12 Dec 1998) |
| nevus, epithelioid and spindle cell | A benign compound nevus occurring most often in children before puberty, composed of spindle and epithelioid cells located mainly in the dermis, sometimes in association with large atypical cells and multinucleate cells, and having a close histopathological resemblance to malignant melanoma. The tumour presents as a smooth to slightly scaly, round to oval, raised, firm papule or nodule, ranging in colour from pink-tan to purplish red, often with surface telangiectasia. (12 Dec 1998) |
| node of Aschoff and Tawara | <cardiology> The location in the heart's conduction system, between the atria and the ventricles, which conducts the normal electrical impulse from the atria to the ventricles. (27 Sep 1997) |
| Novy and MacNeal's blood agar | A nutrient agar containing two volumes of defibrinated rabbit's blood; suitable for the cultivation of a number of trypanosomes. (05 Mar 2000) |
| nucleic acids, nucleotides, and nucleosides | Complex compounds of high molecular weight occurring in living cells. These are basically of two types, ribonucleic (RNA) and deoxyribonucleic (DNA) acids, both of which consist of nucleotides (nucleoside phosphates linked together by phosphate bridges). (12 Dec 1998) |
| D and C | This gynaecological procedure involves dilating the cervix (opening to the uterus) such that a surgical curette may be passed into the uterus. The surgeon uses the curette to remove the inner lining of the uterus (endometrium). This procedure is often performed to correct dysfunctional uterine bleeding. (27 Sep 1997) |
| nutritional and metabolic diseases | A collective term for nutritional disorders (result of poor assimilation or utilization of food) and metabolic disorders (result of poor metabolism or inherited enzyme abnormality). (12 Dec 1998) |
| superior branch of the right and left inferior pulmonary veins | Tributaries of the right and left inferior pulmonary veins which receive oxygenated blood from the superior [S6] bronchopulmonary segments of the inferior lobes of the right and left lungs. Synonym: ramus superior venae pulmonalis dextrae/sinistrae inferioris. (05 Mar 2000) |
| deductibles and coinsurance | Cost-sharing mechanisms that provide for payment by the insured of some portion of covered expenses. Deductibles are the amounts paid by the insured under a health insurance contract before benefits become payable; coinsurance is the provision under which the insured pays part of the medical bill, usually according to a fixed percentage, when benefits become payable. (12 Dec 1998) |
| deficiency dermatitis and diarrhoea, zinc | A genetic disease called acrodermatitis enteropathica is characterised by the simultaneous occurrence of skin inflammation (dermatitis) and diarrhoea. The skin on the cheeks, elbows and knees and tissue about the mouth and anus are inflammed. There is also balding of the scalp, eyebrows and lashes, delayed wound healing and recurrent bacterial and fungal infections due to immune deficiency. The key laboratory finding is an abnormally low blood zinc level reflecting impaired zinc uptake. Oral treatment with zinc is curative. (12 Dec 1998) |