toxin

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toxin

 [tok´sin]
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.
streptococcal toxin a mixture of exotoxins formed by Streptococcus pyogenes.
tetanus toxin the potent exotoxin produced by Clostridium tetani, consisting of two components, one a neurotoxin (tetanospasmin) and the other a hemolysin (tetanolysin).

tox·in

(tok'sin),
A noxious or poisonous substance that is formed or elaborated either as an integral part of the cell or tissue (endotoxin), 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]

toxin

(tŏk′sĭn)
n.
1. A poisonous substance, especially a protein, that is produced by living cells or organisms and is capable of causing disease when introduced into the body tissues but is often also capable of inducing neutralizing antibodies or antitoxins.
2. A poisonous or harmful nonbiological substance, such as a pollutant.

toxin

A poison or noxious thing produced by animals, plants, or bacteria. See Amatoxin, Anaphylatoxin, Bacterial toxin, Batrachotoxin, Biotoxin, Botulinum toxin, Bungarotoxin, Coley's toxin, Endotoxin, Exotoxin, Heat-stable toxin, Immunotoxin, Lethal toxin, Middle molecule toxin, Neurotoxin, Phallotoxin, Picrotoxin, Recombinant toxin, Rhizotoxin, Shiga neurotoxin, Tetanospasmin.

tox·in

(tok'sin)
1. A noxious or poisonous substance that is formed or elaborated 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.
2. A common misnomer for poison.
[G. toxikon, poison]

toxin

Any substance produced by a living organism that is poisonous to other organisms. Bacterial disease is largely the result of poisoning by the toxins they produce. Some bacteria release soluble exotoxins that act remotely. Others produce only endotoxins which operate only locally. Some bacterial toxins are among the most poisonous substances known.

toxin

a nonenzymic metabolite of one organism which is injurious to another organism. see TETANUS, BOTULISM.

Toxin

A poison. In the case of scarlet fever, the toxin is secreted as a byproduct of the growth of the streptococcus bacteria and causes a rash.

tox·in

(tok'sin)
Noxious or poisonous substance formed or elaborated either as an integral part of the cell or tissue (endotoxin), as an extracellular product (exotoxin), or as a combination, during metabolism and growth of some microorganisms and some higher plant and animal species.
[G. toxikon, poison]
References in periodicals archive ?
[USA], June 28 (ANI): Scientists have discovered an environment-friendly toxin belonging to botox family that selectively targets mosquitos and could reduce malaria.
This happens when infants ingest the spores which germinate into bacteria that colonize in the gut and release toxins. 'In most adults and children older than about six months, this would not happen because natural defenses in intestines that develop over time prevent germination and growth of the bacterium,' the WHO says.
The toxin, dubbed BoNT/En, is the ninth botulinum toxin to be described.
Patients who were positive for toxin had a higher case-fatality rate than those who were either toxigenic culture-positive but toxin-negative, or those who were negative by both methods, leading the authors to conclude that a positive toxin result exhibited greater accuracy for CDI, and identified patients who needed treatment.
Caption: ARS chemist Reuven Rasooly and bioscience technician Paula Do studying foodborne toxins. (Stephen Ausmus, D1418-9)
The adsorbed toxin is less accessible to microbial degradation, and its insecticidal activity can persist for a long period [11], probably enhancing the control on target pests at the same time carrying a hazardous effect on nontarget organisms.
All assays performed with the above protocol ended with the successful fixation of the toxins to the MB.
In a previous paper, Kudryashov and colleagues described how toxins' lack of structural rigidity is a secret to their success--they can unfold themselves to cross a host cell membrane and then refold into their toxic structure on the other side, within the cell.
Cytotoxins are deadly to all cells, but since the late 1990s, researchers have been able to tag toxins in such a way that they only enter cancer cells with specific surface molecules; making it possible to get a toxin into a cancer cell without posing a risk to normal cells.
coli where toxin RelE from RelBE module cleaves mRNA of a protein coding gene in a specific manner.
This collaboration will combine Harvard's discovery platform and botulinum toxins engineering expertise with Ipsen's expertise in drug discovery and pharmaceutical R&D.
Our detox system (which comprises mainly of the liver and the intestinal tract) is capable of getting rid of the toxins that we are exposed to on a daily basis.