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secretion

(Encyclopedia)secretion, in biology, substance elaborated by the living material of an animal or plant. Secretions in humans can be produced by a single cell or by a group of cells commonly called a gland. Some sec...

Beutler, Bruce Alan

(Encyclopedia)Beutler, Bruce Alan, 1957–, American immunologist and geneticist, b. Chicago, Ill., M.D. Univ. of Chicago, 1981. Beutler has been a professor and physician at Rockefeller Univ. (1984–86), a facult...

Campbell, Keith

(Encyclopedia)Campbell, Keith, 1954–2012, British cell biologist, b. Birmingham, England, Ph.D. Univ. of Sussex, 1986. In 1991 he joined the Edinburgh Research Station of Animal Physiology and Genetics Research (...

gibberellins

(Encyclopedia)gibberellins jĭbˌərĕlˈĭnz [key], a group of growth-regulating substances of plants, having complex chemical structure, of which the best known, gibberellic acid, is noted for its promotion of st...

histology

(Encyclopedia)histology hĭstŏlˈəjē [key], study of the groups of specialized cells called tissues that are found in most multicellular plants and animals. Histologists study the organization of tissues at all ...

cortisol

(Encyclopedia)cortisol kôrˈtĭsôlˌ [key] or hydrocortisone, steroid hormone that in humans is the major circulating hormone of the cortex, or outer layer, of the adrenal gland. Like cortisone, cortisol is class...

chemotherapy

(Encyclopedia)chemotherapy kēˌmōthĕrˈəpē [key], treatment of disease with chemicals or drugs. One chemotherapeutic approach is the development of selectively toxic substances, i.e., substances that can destr...

emphysema

(Encyclopedia)emphysema ĕmfĭsēˈmə [key], pathological or physiological enlargement or overdistention of the air sacs of the lungs. A major cause of pulmonary insufficiency in chronic cigarette smokers, emphyse...

retrovirus

(Encyclopedia)retrovirus, type of RNA virus that, unlike other RNA viruses, reproduces by transcribing itself into DNA. An enzyme called reverse transcriptase allows a retrovirus's RNA to act as the template for th...

hair

(Encyclopedia)CE5 A. Cross section of a hair shaft B. General structure of a hair hair, slender threadlike outgrowth from the skin of mammals. In some animals hair grows in dense profusion and is called fur or ...