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28 Cards in this Set
- Front
- Back
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What is the source of the cyanobacteria (blue-green algae) toxin?
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Single- celled organisms found in fresh water
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When is the cyanobacteria toxin released?
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Upon death of cyanobacteria
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Cyanobacteria produce toxins which can be _____toxic or _____toxic.
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Neurotoxic or hepatotoxic
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What are the 2 common neurotoxins produced by cyanobacteria?
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Anatoxin a
Anatoxin a(s) |
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What is the mode of action of anatoxin a?
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Nicotinic agonist at the cholinergic receptors
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What is the mode of action of anatoxin a(s)?
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Irreversible acetylcholinesterase inhibitor
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What kind of toxin is microcystin?
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Hepatotoxin produced by cyanobacteria
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What is the mode of action of microcystin?
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Alters the cytoskeleton of liver cells by inhibiting serine/threonine phosphatases type 1 and type 2A
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How long does it take for the onset of neurotoxis produced by cyanobacteria?
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Extremely poisonous and can kill w/in a few minutes
-so toxic animals are sometimes found next to contaminated water |
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What are the clinical signs of anatoxin-a?
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Shows a rapid onset of rigidity and muscle tremors
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Anatoxin-a causes acetylcholinesterase inhibition similar to ______________.
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Organophosphorous/ carbamate insecticides
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Do neurotoxins or hepatotoxins kill more rapidly?
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Neurotoxins
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Is death from anatoxin a(s) or microcystin more rapid?
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Anatoxin a(s), the neurotoxins kill animal more rapidly
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What are the clinical signs of microcystin toxicity?
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-GI disturbances
-destruction of hepatocytes soon after ingestion |
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When does death occur from microcystin toxicity? How?
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Death from liver failure often within 24 hours
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How do you diagnose anatoxin-a or anatoxin-a(s) toxicity?
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-History of exposure to blue-green algae
-clinical signs -possible presence of algae in GI tract -no gross or microscopic lesions |
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What do you find on postmortem examination in an animal with microcystin toxicity?
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Liver often enlarged, swollen and dark red
-sometimes significant edema around gall bladder |
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What do you see on histology of an animal with microcystin toxicity?
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Massive liver necrosis w/ severe intrahepatic hemorrhage
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Is anatoxin-a or anatoxin-a(s) more toxic?
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Anatoxin-a(s) is much more toxic
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What is the LD50 for microcystin?
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b/w 50 and 11,000 ug/kg depending on microcystin structure
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How do you diagnose microcystin toxicity?
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Gross & histologic liver lesions
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What do you see on clinical pathology of anatoxins?
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No significant findings
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What do you see on clinical pathology of microcystins?
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Increase in serum ALP, AST, ALT, bilirubin
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What are the lesions present in an animal with anatoxicosis?
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No lesions present
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What are the lesions present in an animal with microcystin toxicity? (3)
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1) Liver enlargement
2) Interhepatic hemorrhage 3) Progressive centrilobular hepatocyte rounding, dissociation & necrosis |
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Is there a treatment for cyanobacteria toxicity?
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No antidote, rapid onset of clinical signs
-Need aggressive and intensive care -Provide supportive care |
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What is the prognosis of cyanobacteria toxicity?
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POOR
-animals usually found dead |
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How do you prevent cyanobacteria toxicity?
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Deny access to water w/ visible algal blooms
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