Toxins prevention

Focal spasticity Botulinum toxin Prevents release of acetylcholine in the neuromuscular junction Individualized... 

Altered release. Tetanus is an infectious disease caused by the bacterium Clostridium tetani. This bacterium produces a neurotoxin active on inhibitory synapses in the spinal cord. Motor neurons, which supply skeletal muscle and cause contraction, have cell bodies that lie in the spinal cord. Under normal circumstances, these motor neurons receive excitatory and inhibitory inputs from various sources. The balance of these inputs results in the appropriate degree of muscle tone or muscle contraction. Tetanus toxin prevents the release of gamma amino butyric acid (GABA), an important neurotransmitter active at these inhibitory synapses. Eliminating inhibitory inputs results in unchecked or unmodulated excitatory input to the motor neurons. The resulting uncontrolled muscle spasms initially occur in the muscles of the jaw, giving rise to the expression lockjaw. The muscle spasms eventually... 

Botulinus toxin comes from Clostridium botulmum, an organism that causes food poisoning. Botulinus toxin prevents the release of ACh from nerve endings by mechanisms that are not clear. Death occurs from respiratory failure caused by the inability of diaphragm muscles to contract. 

By destroying the protein, the toxin prevents the release of the neurotransmitter acetylcholine from small packets at the ends of nerves by exocytosis. These nerves, attached to voluntary muscles, need acetylcholine to allow the flow of signals (impulses) between the nerve and the muscle. By preventing the release of acetylcholine, botulinum toxin blocks muscle contraction, causing paralysis and relaxation. The therapeutic action relies on relaxation of muscles, generally in the face. It is therefore used to treat blepharospasm (uncontrolled contractions) and stroke-induced permanent facial muscle contractions. 

Food-borne botulism results from the ingestion of food contaminated with preformed toxins or toxin-producing spores from C. bo-tulinum. C. botulinum poisoning is relatively rare only 110 cases are reported per year in the United States. Botulism is almost always associated with improper preparation or storage of food. Seven distinct toxins (A to G) have been described. The toxins, which are produced by the bacteria and released on lysis, are the most potent biologic or chemical toxins known to humans. The toxin prevents the release of acetylcholine at the peripheral cholinergic nerve terminal. Toxin activity has prompted the use of minute locally injected doses to treat select spastic disorders, such as blepharospasm, hemifacial spasm, and certain dystonias. ... 

A FIGURE 17-36 Release of neurotransmitters and the recycling of synaptic vesicles. Step D Synaptic vesicles loaded with neurotransmitter (red circles) move to the active zone and then dock at defined sites on the plasma membrane of a presynaptlc cell. Synpatotagmin prevents membrane fusion and release of neurotransmitter. Botulinum toxin prevents exocytosls by proteolytically cleaving VAMR the v-SNARE on vesicles. Step... 

Wilson, P.D., Dixon, B.S., Dillingham, M.A., Garda-Sainz, J.A. and Anderson, R.J. (1986). Pertussis toxin prevents homologous desensitization of adenylate cydase in cultured renal epithelial cells. ]. Biol Chem., 261, 1503-1506... 

Pasteurella multocida P. multocida toxin Prevents human DC migration" Activates human and mouse DC" Inhibits LPS-induced IL-12 production from human DC" ... 

To conclude, DON occurrence is almost exclusively associated with cereals, and the levels of occurrence are in the order of hxmdreds of pg/kg upwards. DON occurs as a field (preharvest) rather than a storage contarninant, and almost always co-occurs with other Fusarium toxins. Preventive measures are difficult to implement, and even the effect of fungicide treatment on DON levels is controversial (Edwards et al., 2001). As seasonal variations significantly influence the extent of Fusarium infections, levels of DON tend to... 

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