noun
definition
A toxic or poisonous substance produced by the biological processes of biological organisms.
Examples of toxin in a Sentence
The serum of the animal is tested from time to time against a known amount of toxin, i.e.
By growing this bacillus in broth a toxin is formed which remains in solution and can be separated from the bacilli themselves by filtration.
Then we have the property of adaptation, in which the negative reaction may be changed into a positive; a given toxin may at first repel the cell, but by a gradual process the cell becomes accustomed to such a toxin and will move towards it.
Of such are tetanus and diphtheria, now known to be due to the establishment from without of a local microbic infection, from which focus a toxin is diffused to the nervous matter.
Though an enormous of amount of work has been done on the subject, no important bacterial toxin has as yet been obtained in a pure condition, and, though many of them are probably of proteid nature, even this cannot be asserted with absolute certainty.
In the earlier experiments on smaller animals the potency of the toxin was modified for the first injections, but in preparing antitoxin for therapeutical purposes the toxin is used in its unaltered condition, the horse being the animal usually employed.
The unit of antitoxin in Ehrlich's new standard is the amount requisite to antagonize i oo times the minimum lethal dose of a particular toxin to a guinea-pig of 250 grm.
The secretion of trypsin by the pancreas may therefore be looked upon as the formation of a toxin.
By immunity is meant non-susceptibility to a given disease, or to experimental inoculation with a given bacterium or toxin.
The antitoxic property is developed in a susceptible animal by successive and gradually increasing doses of the toxin.
The origin of antitoxin is of course merely a part of the general question regarding the production of anti-substances in general, as these all combine in the same way with their homo logous substances and have the same character of g toxin.
In such a case it has been shown that, without the introduction of fresh toxin, new antitoxin appears, and therefore must be produced by the living tissues.
By the introduction of fresh toxin the process is repeated and the regeneration of side-chains is increased.
In other words the substances, which when forming part of the cells fix the toxin to the cells, constitute antitoxin molecules when free in the serum.
Wassermann and Takaki in the case of tetanus, that there do exist in the nervous system molecules with combining affinity for the tetanus toxin.
If, for example, the brain and spinal cord removed from an animal be bruised and brought into contact with tetanus toxin, a certain amount of the toxicity disappears, as shown by injecting the mixture into another animal.
As a rule it has no action on the corresponding toxin, i.e.
Natural immunity against toxins must be taken into account, and, if Ehrlich's view with regard to toxic action be correct, this may depend upon either the absence of chemical affinity of the living molecules of the tissues for the toxic molecule, or upon insensitiveness to the action of the toxophorous group. It has been shown with regard to the former, for example, that the nervous system of the fowl, which possesses immunity against tetanus toxin, has little combining affinity for it.
Wharfinger states that in chlorosis the specific action of iron is only obtained by administering those inorganic preparations which give a reaction with the ordinary reagents; the iron ions in a state of dissociation act as a catalytic agent, destroying the hypothetical toxin which is the cause of chlorosis.
With regard to the bacillary type, at first both organisms were considered to be identical, and the name bacillus dysenteriae was given to them; but later it was shown that these bacilli are different, both in regard to their cultural characteristics and also in that one (Shiga) gives out a soluble toxin, whilst the other has so far resisted all efforts to discover it.
The effects of many of these toxins bear a close resemblance to the action of certain wellknown drugs, as in the case of tetanus toxin and strychnine, and are studied by the same methods of observation and research.
In specific germ diseases a similar antitoxin forms, and in cases which recover it counteracts the toxin, while the germs are destroyed by the tissues.
The potatoes were genetically modified to include a toxin - GNA lectin - found in snowdrops to make them resistant to potato aphids.
For example, genes from the bacterium bacillus thuringiensis produce a toxin that kills certain insects.
They now think she could have become intoxicated by a natural toxin found in algae blooms.
The fusion toxin was active against two insect pests of rice, leaf folder and yellow stem borer.
These bacteria produce a toxin in food which causes a severe illness called botulism which can be fatal.
Welcome to Herbal Fusion - Botox is made from ' botulinum toxin ', a poison produced by the bacterium clostridium botulinum.
Product Overview TransMID TM is a modified diphtheria toxin conjugated to transferrin.
Ama is the most common type of toxin, and is the waste product of incomplete digestion.
The toxin is sometimes present in the milk of cattle which have been given feed containing henbane.
The toxin is released in root exudates from a number of maize hybrids expressing three different transformation events [22] .
The first was developed by chemical modification of a toxin from a marine invertebrate.
Research has shown that rice leafhoppers are controlled by GM rice with Cry1Ab toxin.
This is because kidney beans contain a natural toxin (called lectin) that can cause stomach aches and vomiting.
A detox is a regime designed to reduce the toxin levels in our bodies.
They accidentally produced the toxin MPTP, and this caused the drug users to develop parkinsonism almost overnight.
The toxin released into the soil affected the enzymes of soil microbes, increasing soil acid phosphatase and decreasing soil urease [10] .
Carbon dioxide stimulates production of the toxin in vitro (outside the body ).
Researchers have developed a plant-based vaccine against bacterial Shiga toxin, and show that it is highly protective in mice.
They were alleged to have been involved in a plot to spread ricin, a deadly toxin.
Senate Majority Leader Bill Frist announced progress in decontamination efforts at the Dirksen Senate office building, where the toxin ricin was found Monday.
Baghdad has mobile facilities for producing bacterial toxin BW agents; these facilities can evade detection and are highly survivable.
Investigation of the neuronal aggregate generating seizures in the rat tetanus toxin model of epilepsy.
The duration before onset of symptoms depends on the time taken for ingested toxin to reach the target site.
Protection of frontline workers The release of a Botulinum toxin aerosol will create an exposed zone that presents a high risk of inhaling toxin.
This natural pathogen produces an insecticidal toxin which leaves humans and beneficial insects unaffected.
At a secret meeting in Miami, they furnished him with tiny gelatine capsules filled with botulinum toxin.
The ubiquity of such crops has also allowed the Bt toxin class to become the most widely used in the world.
Once inside a cell the diphtheria toxin interferes with protein synthesis which ultimately kills the cancer cell.