injuries and poisoning
Toxins as Weapons
Botulinum Toxin
 Botulism , or botulinum neurotoxin, refers to any of eight known types of neurotoxins produced by the bacterium Botulinum neurotoxin blocks one of the types of chemicals that nerve cells use to send signals to other nerve cells and to muscles (neurotransmitters). Because the particular signaling chemical, acetylcholine, does not work properly, people become weak or paralyzed. Typically the paralysis starts at the top of the body about 12 to 36 hours (range 2 hours to 8 days) after exposure to botulinum neurotoxin and extends downward. The toxin does not enter the brain, so thinking is not affected. Diagnosis is made based on the person's symptoms. Doctors give an antitoxin by vein. The antitoxin acts only against toxin circulating in the blood and not against toxin already attached to nerve cells. Thus, antitoxin prevents worsening of symptoms and signs but does not help relieve them and becomes progressively less effective as symptoms and signs develop. 