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poisonous plant

(Encyclopedia)poisonous plant, any plant possessing a property injurious to man or animal. Plants may be poisonous to the touch (e.g., poison ivy, poison sumac), or orally toxic (e.g., poison hemlock, deadly amanit...

collagen

(Encyclopedia)collagen kŏlˈəjən [key], any of a group of proteins found in skin, ligaments, tendons, bone and cartilage, and other connective tissue. Cells called fibroblasts form the various fibers in connecti...

vegetative propagation

(Encyclopedia)vegetative propagation, the ability of plants to reproduce without sexual reproduction, by producing new plants from existing vegetative structures. Some plants, such as the Canada thistle and most ba...

Crofton, Sir John Wenman

(Encyclopedia)Crofton, Sir John Wenman, 1912–2009, British physician, b. Dublin. He served in the British medical corps during World War II and during 1946–52 was part of a research team studying the effects of...

epidemiology

(Encyclopedia)epidemiology, field of medicine concerned with the study of epidemics, outbreaks of disease that affect large numbers of people. Epidemiologists, using sophisticated statistical analyses, field invest...

orphan drug

(Encyclopedia)orphan drug, drug developed under the U.S. Orphan Drug Act (1983) to treat a disease that affects fewer than 200,000 people in the United States. The orphan drug law offers tax breaks and a seven-year...

Charcot, Jean Martin

(Encyclopedia)Charcot, Jean Martin zhäN märtăNˈ shärkōˈ [key], 1825–93, French neurologist. At the Salpêtrière in Paris he developed the greatest clinic of his time for diseases of the nervous system. He...

genetic engineering

(Encyclopedia)CE5 Genetic engineering: Gene-splicing techniques genetic engineering, the use of various methods to manipulate the DNA (genetic material) of cells to change hereditary traits or produce biologica...

intoxication

(Encyclopedia)intoxication, condition of body tissue affected by a poisonous substance. Poisonous materials, or toxins, are to be found in heavy metals such as lead and mercury, in drugs, in chemicals such as alcoh...

Nematoda

(Encyclopedia)Nematoda nĕmˌətōdˈə [key], phylum consisting of about 12,000 known species, and many more predicted species, of worms (commonly known as roundworms or threadworms). Nematodes live in the soil an...