Nutritional/Tox Flashcards
Name 4 risk factors for copper deficiency
Excess zinc intake, gastric bypass surgery, deficiency in parenteral nutrition, overuse of denture cream
What are the symptoms of copper deficiency?
Myelopathy similar to that seen with B12 deficiency, pancytopenia, sensorimotor neuropathy with axonal loss
Name 3 risk factors for Vitamin E deficiency
Chronic diarrhea/malabsorption, bowel resection, genetic (abetalipoproteinemia)
What are the symptoms of Vitamin E deficiency?
ataxia, dysarthria, areflexia, large fiber sensory loss, acanthocytes on peripheral smear. Ocular: night blindness, impaired up gaze, strabismus.
What deviations are seen in homocysteine and MMA with B12 deficiency? Folate deficiency?
Elevated homocysteine and MMA with B12 deficiency. Elevated homocysteine and normal MMA with folate deficiency.
A child ingested large amounts of soil from his backyard. 2 hours later presents with abdominal pain, vomiting, a garlic odor to his breath. An abdominal X-ray shows radiopaque material. What toxin is likely in the soil?
Arsenic. can also cause hypotension, delirium, seizures with acute poisoning.
A man with peripheral neuropathy, white transverse banding lines in his fingernails (Mee’s lines), mild GI symptoms, and newly diagnosed skin cancer likely has chronic poisoning with which substance?
Arsenic (and old lace)
Chelation therapy with which two substances can be use for arsenic poisoning?
Dimercaprol and succimer
What is the mechanism of action of cyanide?
Mitochondrial toxin. Competes with oxygen for binding to cytochrome oxidase, causing cessation of phosphorylation. Cells must then utilize anaerobic metabolism.
Carbon monoxide poisoning classically causes MRI abnormalities in which brain area?
Hypoxic injury/necrosis of the globus pallidus
What MRI findings are classically seen in methanol poisoning?
Necrosis of the optic nerves and putamen
What can be used to treat methanol poisoning?
Alcohol (will compete with methanol for binding) or fomepizole
What is the mechanism of action of organophosphates?
Potent cholinesterase inhibitors which cause cholinergic crisis
How can organophosphate poisoning be treated?
Atropine + pralidoxime
How does botulinum toxin cause paralysis?
Toxin binds to the synaptotagmin II receptor presynaptically. Light chain is taken into the cell where it irreversibly inhibits ACh release by cleaving proteins needed to exocytose ACh.
