- One of a number of poisons produced by certain plants, animals, and bacteria. The term "toxin" is frequently used to refer specifically to a particular protein produced by some higher plants, animals and pathogenic (disease-causing) bacteria. A toxin typically has a high molecular weight (as compared to a simple chemical poison), is antigenic (elicits an antibody response), and is highly poisonous to living creatures. The word "toxin" comes from the Greek "toxikon" = arrow poison and was introduced to medicine in 1888 by the Berlin physician Ludwig Brieger (1849-1909) as a name for poisons made by infectious agents.
* * *A noxious or poisonous substance that is formed or elaborated either as an integral part of the cell or tissue, as an extracellular product (exotoxin), or as a combination of the two, during the metabolism and growth of certain microorganisms and some higher plant and animal species. [G. toxikon, poison]- anthrax t. a culture filtrate of Bacillus anthracis containing an exotoxin with at least three different antigenically distinct components: edema factor, lethal factor, and protective antigen. SYN: Bacillus anthracis t..- Bacillus anthracis t. SYN: anthrax t..- bee t. the t. delivered by a bee sting; contains three active principles: biogenic amines, active peptides, and certain hydrolytic enzymes.- botulinus t. a potent exotoxin that is highly neurotoxic from Clostridium botulinum. SYN: botulin, botulismotoxin.- cholera t. Vibrio cholerae.- Clostridium perfringens alpha t. a phospholipase produced by Clostridium perfringens that increases vascular permeability and produces necrosis.- Clostridium perfringens beta t. a substance produced by Clostridium perfringens that causes necrosis and induces hypertension by causing release of catecholamine.- Clostridium perfringens epsilon t. a t. produced by Clostridium perfringens that increases the permeability of the gastrointestinal wall.- Clostridium perfringens iota t. a binary t. produced by Clostridium perfringens responsible for necrosis and increased vascular permeability.- Crotalus t. the t. of rattlesnake.- dinoflagellate t. a potent neurotoxin that is thought to act similarly to botulinus t. by impairing the synthesis or the release of acetylcholine. Responsible for “red tide” loss of shellfish.- diphtheria t. Corynebacterium diphtheriae.- plant t. SYN: phytotoxin.- Schick test t. Corynebacterium diphtheriae t. diluted so that the inoculated dose (0.1 or 0.2 mL) will contain 150th of a guinea pig minimal lethal dose. SEE ALSO: Schick test. SYN: diagnostic diphtheria t..- Shigalike t. SYN: vero cytotoxin.- streptococcus erythrogenic t. a culture filtrate of lysogenized group A strains of β-hemolytic streptococci, erythrogenic when inoculated into the skin of susceptible persons, and neutralized by antibodies that appear during scarlet fever convalescence; three immunologic types (A, B, and C) are recognized. SYN: Dick test t., erythrogenic t., scarlet fever erythrogenic t..- tetanus t. the neurotropic, heat-labile exotoxin of Clostridium tetani and the cause of tetanus; it has been isolated as a crystalline protein (molecular weight 67,000), is one of the most poisonous substances known, and seems to function by blocking inhibitory synaptic impulses. SYN: tetanotoxin.
* * *tox·in 'täk-sən n a colloidal proteinaceous poisonous substance that is a specific product of the metabolic activities of a living organism and is usu. very unstable, notably toxic when introduced into the tissues, and typically capable of inducing antibody formation
* * *n.a poison produced by a living organism, especially by a bacterium (see endotoxin, exotoxin). In the body toxins act as antigen, and special antibody (antitoxins) are formed to neutralize their effects.
* * *tox·in (tokґsin) [Gr. toxikon (pharmakon) poison for arrows, from toxon bow] a poison; frequently used to refer specifically to a protein that is produced by some higher plants, certain animals, or pathogenic bacteria and is highly toxic for other living organisms. Such substances are differentiated from the simple chemical poisons and the vegetable alkaloids by their high molecular weight and antigenicity. toxic adj
Medical dictionary. 2011.