Botulinum toxins lethality

Botulinum antitoxin Neutralizatien ef the lethal effects of botulinum toxins A, B and E in mice SOOlUmI- eftypeA 5001U mM ef Type B 50IU ml- ef Type E... 

Botulinum Toxin 1. Sabotage (food/ water supply) 2. Aerosol No Variable (hours to days) 24-72 hours Months if lethal High Stable Yes Not effective Yes... 

C. botulinum toxins cause botulism. They are among the most toxic substances known. A lethal dose for humans is 1 microgram (a millionth of a gram). In a... 

Treatment—Since C. botulinum toxin blocks the actions of nerves that activate muscles necessary for breathing, an antitoxin can be injected up to about 24 hours (based on monkey studies) after exposure to a lethal toxin dose and still prevent death. The two types of available antitoxins prepared from horse sera are trivalent (includes types A, B, E) and heptavalent (types A, B, C, D, E, F, and G) preparations. It should be noted that patients face a theoretical risk of developing serum sickness from such antitoxins. 

The two substances - sucrose and botulinum toxins - differ in lethality by about 10 billion times The acute lethal doses of most chemicals fall into a much narrower range, but there are many substances near the two extremes of this distribution of lethal doses. 

Botulinum toxin from Clostridium botulinum is the most potent poison known. The lethal dose in an adult is approx. 3x10 mg. The toxin blocks exo-cytosis of ACh in motor (and also parasympathetic) nerve endings. Death is caused by paralysis of respiratory muscles. Injected intramuscularly at minuscule dosage, botulinum toxin type A is used to treat blepharospasm, strabismus, achalasia of the lower esophageal sphincter, and spastic aphonia. 

Acetylcholine release is inhibited by one of the most potent toxins, the botulims toxin produced by the anaerobic bacterium Clostridium botulinum. The toxin, lethal at 1 ng/kg in humans, enters the synapse by endocytosis at nonmyelinated synaptic membranes and produces muscle paralysis by blocking the active zone of the presynaptic membrane... 

Food may be contaminated with toxins produced by bacteria, such as botulinum toxin. This is produced by the bacterium Clostridium botulinum and is one of the two most potent toxins known to humans (the other being ricin). As little as one hundred-millionth of a gram (1 X 10-8 g) of the toxin would be lethal for a human. Fortunately, the toxin is destroyed by heat so that cooked food is unlikely to be contaminated (although the bacterial spores are quite resistant). The bacteria grow in the absence of air (they are anaerobic), and consequently, the foodstuffs most likely to be contaminated are those that are bottled or canned and eaten without cooking, for example, raw or lightly cooked fish. 

Consequently, botulinum toxin represents a strategy for dealing with spasticity that is especially problematic in specific muscles or groups of muscles. Despite the rather ominous prospect of injecting a potentially lethal toxin into skeletal muscles, this intervention has a remarkably small incidence of severe adverse effects when administered at therapeutic doses.5,44 Botulinum toxin can therefore be used as part of a comprehensive rehabilitation program to provide optimal benefits in certain patients with severe spasticity. 

Botulinum toxin is produced by the bacterium Clostridium botulinum. It is among the most lethal substances known, and it has been estimated that 1-2 ounces of the pure toxin could kill the entire population of the United States. Poisoning of man and animals occurs when food containing the toxin is ingested. The most common source is improperly prepared canned fruits and vegetables or fish products. Although only... 

The idea of a bioterrorist attack involving botulism stems largely from the extreme lethality of the botulinum toxin. Unsuccessful attempts have already been made to aerosolize botulinum toxin by a Japanese cult between 1990 and 1995. The United States... 

Initial concentration of botulinum toxin was 1 X 10 mouse minimum lethal dose/ml. 

Botulinum toxin is on the A list of potential bioterrorist weapons because of its toxicity, its lethality, its ease of production, ease of transport, ease of use, and the need for prolonged, intensive care of affected victims (36). The colorless, odorless, and probably tasteless toxin is the most poisonous substance known (36). The most efficient route of exposure through a terrorist attack would be inhalational, causing a distribution of illness distinctly different from naturally occurring human botulism. One gram of crystalline toxin dispersed through an airborne route, could kill up to 1 million people, although technical limitations on dispersal could reduce the number of casualties (36). 

Terrorists are unlikely to use therapeutic, cosmetic botulinum toxin (FDA approved in 2002) because the commercial preparation contains only 0.3% of the injectable lethal dose and 0.005% of the lethal oral dose (37). 

That nature is not benign, indeed that it can be extremely deadly, is another lesson to take away from this section. While chemists have been successful in creating some highly lethal agents, none of these quite matches the likes of botulinum toxin, cobra venom or the poison in puffer fish (tetrodotoxin). 

The botulinum toxins are so very toxic that lethal aerosol MCBW weapons could be produced with quantities of toxin that are relatively easily attainable with present technology. They cause death through paralysis of respiratory muscles without producing microscopic change in the tissues. 

Intoxications such as this can be treated with antitoxin injected hours after exposure to a lethal dose of toxin (< 24 h in monkeys, and probably also in humans), and still prevent illness and death. Although the mechanisms of toxicity of the botulinum toxins appear to be the same after any route of exposure, the actual toxicity of the botulinum toxins is less by inhalation. 

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