Botulinum toxin prevents the release of what neurotransmitter at the neuromuscular junction for up to 5 months?

How does Botulinum toxin affect neurotransmitter release?Group of answer choicesIt promotes neurotransmitter release.It blocks the release by cleaving docking proteins.It increases the number of active receptors.It has no effect on neurotransmitters.

A 47-year-old woman was admitted to the hospital afterexperiencing nausea and vomiting for about 2 days followed bysevere muscle weakness and neurologic symptoms, includingptosis and dysphagia. She indicated she had eaten at a restaurantthe evening before the symptoms began. Laboratory tests werepositive for Clostridium botulinum. The basis for the muscleweakness in this case was most likely because the toxinA. blocked the reuptake of neurotransmitter into presynapticterminals.B. bound irreversibly to the receptor on the postsynapticmembrane at the neuromuscular junction.C. reached the cell body of the motor neuron by diffusion intothe spinal cord.D. exerted its adverse effects by a direct action on the skeletalmuscle.E. prevented the release of acetylcholine from motor neurons.

Passage 3 (Questions 11 - 15)A woman began canning her own jams as a hobby. She shared several cans of her jam with her mother for lunch. The next day, her mother was found suffering from blurry vision, difficulty swallowing and troubled breathing. Given the quick progression of symptoms, associated with the new food, the ER physician suspected botulism poisoning. Due to the danger and toxicity of botulism, tests were performed immediately to determine the best course of treatment.The botulinum toxin is a neurotoxin produced by the bacterium Clostridium botulinum. Botulism is a life-threatening illness in humans, although forms of the toxin are used for various cosmetic and medical procedures. The eight distinct toxin types are designated A to H. The botulinum toxin protein is a two-chain polypeptide with a 100-kDa heavy chain joined by a disulfide bond to a 50-kDa light chain. This light chain is a protease that attacks one of the fusion proteins (SNARE protein) present in neuromuscular junctions, preventing vesicles from anchoring with the cell membrane to release acetylcholine.Figure 1 Mechanism of neuromuscular blockade by botulinum toxinThe tests employed to detect botulism include brain scans and nerve conduction tests. Toxicity testing of serum specimens, wound tissue cultures, and stool specimen cultures are the best methods for identifying botulism, though they are time-consuming. If the symptoms are diagnosed early, treatment can reduce the case fatality rate to less than 10%, while untreated botulism is fatal in nearly half of cases. A more rapid way to detect the toxin in humans utilizes mass spectrometry. Question 11What is a likely neurological symptom caused by the toxin's effect on acetylcholine release? A.TetanusB.Muscle spasmsC.Flaccid paralysisD.Nausea

Passage 3 (Questions 11 - 15)A woman began canning her own jams as a hobby. She shared several cans of her jam with her mother for lunch. The next day, her mother was found suffering from blurry vision, difficulty swallowing and troubled breathing. Given the quick progression of symptoms, associated with the new food, the ER physician suspected botulism poisoning. Due to the danger and toxicity of botulism, tests were performed immediately to determine the best course of treatment.The botulinum toxin is a neurotoxin produced by the bacterium Clostridium botulinum. Botulism is a life-threatening illness in humans, although forms of the toxin are used for various cosmetic and medical procedures. The eight distinct toxin types are designated A to H. The botulinum toxin protein is a two-chain polypeptide with a 100-kDa heavy chain joined by a disulfide bond to a 50-kDa light chain. This light chain is a protease that attacks one of the fusion proteins (SNARE protein) present in neuromuscular junctions, preventing vesicles from anchoring with the cell membrane to release acetylcholine.Figure 1 Mechanism of neuromuscular blockade by botulinum toxinThe tests employed to detect botulism include brain scans and nerve conduction tests. Toxicity testing of serum specimens, wound tissue cultures, and stool specimen cultures are the best methods for identifying botulism, though they are time-consuming. If the symptoms are diagnosed early, treatment can reduce the case fatality rate to less than 10%, while untreated botulism is fatal in nearly half of cases. A more rapid way to detect the toxin in humans utilizes mass spectrometry. Question 14Which of the following is NOT a function of the sympathetic nervous system? A.Increased heart rateB.Pupillary constrictionC.VasodilationD.Vasoconstriction

Passage 3 (Questions 11 - 15)A woman began canning her own jams as a hobby. She shared several cans of her jam with her mother for lunch. The next day, her mother was found suffering from blurry vision, difficulty swallowing and troubled breathing. Given the quick progression of symptoms, associated with the new food, the ER physician suspected botulism poisoning. Due to the danger and toxicity of botulism, tests were performed immediately to determine the best course of treatment.The botulinum toxin is a neurotoxin produced by the bacterium Clostridium botulinum. Botulism is a life-threatening illness in humans, although forms of the toxin are used for various cosmetic and medical procedures. The eight distinct toxin types are designated A to H. The botulinum toxin protein is a two-chain polypeptide with a 100-kDa heavy chain joined by a disulfide bond to a 50-kDa light chain. This light chain is a protease that attacks one of the fusion proteins (SNARE protein) present in neuromuscular junctions, preventing vesicles from anchoring with the cell membrane to release acetylcholine.Figure 1 Mechanism of neuromuscular blockade by botulinum toxinThe tests employed to detect botulism include brain scans and nerve conduction tests. Toxicity testing of serum specimens, wound tissue cultures, and stool specimen cultures are the best methods for identifying botulism, though they are time-consuming. If the symptoms are diagnosed early, treatment can reduce the case fatality rate to less than 10%, while untreated botulism is fatal in nearly half of cases. A more rapid way to detect the toxin in humans utilizes mass spectrometry. Question 12The easiest method to separate the two subunits of the botulinum protein for subsequent analytical purposes would be: A.gas chromatography.B.mass spectrometry.C.thin-layer chromatography.D.size-exclusion chromatography.