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a poison, especially a protein or conjugated protein produced by certain animals, higher plants, and pathogenic bacteria. Bacterial toxins characteristically do not cause symptoms until after a period of incubation while the microbes multiply, or (as happens with botulism) the preformed toxin reaches and affects the tissue. Usually only a few toxin-producing agents are introduced into the body, and it is not until there are enough of them to overwhelm the leukocytes and other types of antibodies that symptoms occur. In some cases of food poisoning, symptoms are almost immediate because the toxin is taken directly with the food. Toxins can cause antitoxins to form in the body, thus providing a means for establishing immunity to certain diseases.
bacterial t's toxins produced by bacteria, including exotoxins, endotoxins, enterotoxins, neurotoxins, and toxic enzymes. See also toxin.
botulinal toxin (botulinum toxin) (botulinus toxin) one of seven type-specific, immunologically differentiable exotoxins (types A to G) produced by Clostridium botulinum,neurotoxins usually found in imperfectly canned or preserved foods. They cause botulism by preventing release of acetylcholine by the cholinergic fibers. Type A is one of the most powerful poisons known; it is also used therapeutically by injection to inhibit muscular spasm in the treatment of dystonic disorders such as blepharospasm and strabismus, to treat wrinkles of the upper face, and to reduce anal sphincter pressure to promote healing of chronic anal fissure. Type B is injected in treatment of cervical dystonia. Called also botulin.
cholera toxin an exotoxin produced by Vibrio cholerae; a protein enterotoxin that binds to the membrane of enteric cells and stimulates the adenylate cyclase system, causing the hypersecretion of chloride and bicarbonate ions, resulting in increased fluid secretion and the severe diarrhea characteristic of cholera.
clostridial toxin one elaborated by species of Clostridium, including those causing botulism (botulinus toxin), gas gangrene (gas gangrene toxin), and tetanus (tetanus toxin). In addition, C. difficile produces an exotoxin causing severe intestinal necrosis and C. perfringens produces exotoxins causing gas gangrene, intestinal necrosis, hemolysis, cardiotoxicity, and deoxyribonuclease and hyaluronidase activity, as well as an enterotoxin causing food poisoning.
Dick toxin erythrogenic toxin.
diphtheria toxin a protein exotoxin produced by Corynebacterium diphtheriae that is primarily responsible for the pathogenesis of diphtheria and related infections; it is an enzyme that activates transferase II of the mammalian protein synthesizing system.
diphtheria toxin for Schick test a sterile solution of the diluted, standardized toxic products of Corynebacterium diphtheriae; used as a dermal reactivity indicator in the schick test of immunity to diphtheria.
dysentery toxin any of various exotoxins produced by species of Shigella; the one formed by S. dysenteriae serotype 1 is a potent neurotoxin with hemorrhagic and paralytic properties.
erythrogenic toxin a bacterial toxin from certain strains of Streptococcus pyogenes that produces an erythematous reaction when injected intradermally and is responsible for the rash in scarlet fever.
extracellular toxin exotoxin.
gas gangrene toxin an exotoxin that causes gas gangrene; there are at least 10 types produced by Clostridium perfringens and others produced by C. noriyi and C. septicum.
tetanus toxin the potent exotoxin produced by Clostridium tetani, consisting of two components, one a neurotoxin (tetanospasmin) and the other a hemolysin (tetanolysin).
botulinum toxin (BTX),
an extremely potent neurotoxin produced by Clostridium botulinum, a gram-positive, strictly anaerobic bacillus; causes botulism when the preformed toxin is ingested in previously contaminated food products. The toxin inhibits release of acetylcholine, a neurotransmitter.
Etymology: L, botulus, sausage; Gk, toxikon, poison
any of a group of potent bacterial toxins produced by different strains of Clostridium botulinum. It may be used therapeutically for blepharospasm or cosmetically to relax facial wrinkles. The strains are sometimes identified by letters of the alphabet, such as A, B, or C. Also called Botox, botulinus toxin.
50-kD neurotoxin with 7 distinct serotypes, produced by strains of Clostridium botulinum, which are billed as the most potent neurotoxins known; type C1 has an LD50 of 32 ng; type A, BTX-A (the cosmetic Botox) has an LD50 of 40-56 ng.
Nausea, diarrhoea, weakness, dizziness, respiratory paralysis, death.
bot·u·li·num tox·in(bot-yū-lī'nŭm tok'sin)
An extremely potent neurotoxin produced by Clostridium botulinum, a gram-positive, strictly anaerobic bacillus; causes botulism when the preformed toxin is ingested in previously contaminated food products. The toxin inhibits release of acetylcholine, a neurotransmitter.
botulinum toxinA powerful EXOTOXIN produced by the organism Clostridium botulinum which, in carefully controlled minute dosage, has been found useful in the treatment of an increasing range of conditions. It is given, often with excellent effect in squint (STRABISMUS) caused by overactive eye muscles; uncontrollable spasm of the eyelid muscles (blepharospasm); NYSTAGMUS; sixth nerve palsy; hyperlacrimation; drooling; spastic club foot (dynamic equinus foot deformity) in children with cerebral palsy; tennis elbow; facial spasm; excessive sweating of the armpits and palms; gustatory sweating; vaginismus; post-stroke spasticity; TORTICOLLIS; WRITER'S CRAMP; other occupational cramps; essential hand tremor; BRUXISM; tics; swallowing difficulty (dysphagia); tension headaches; MIGRAINE; backache; and anal fissure. The toxin can also be used to cause a temporary deliberate drooping of the upper lid (blepharoptosis) as an alternative to sewing the lids together (tarsorrhaphy) for the treatment of corneal ulceration and other conditions. The preparations has also become a popular and, for the providers, lucrative remedy for the cosmetic removal of the appearance of wrinkles.
Botulinum toxin (botulin)
A neurotoxin made by Clostridium botulinum; causes paralysis in high doses, but is used medically in small, localized doses to treat disorders associated with involuntary muscle contraction and spasms, in addition to strabismus.
A poisonous substance which paralyses muscles and leads to inhibition of the release of acetylcholine from presynaptic neuromuscular terminals. The effect can last for weeks after being injected into a muscle. It is used as an alternative or addition to extraocular muscle surgery in the management of strabismus. It is also sometimes used in the management of blepharospasm. Example: In esotropia, the medial rectus muscle is injected to paralyse its action. See chemodenervation.
a neurotoxin produced by Clostridium botulinum; causes botulism. Eight antigenically distinct types are recognized: A, B, C, C2, D, E, F and G.