Prion Diseases Flashcards
What are the similarities and dissimilarities between Alzheimer’s and prion diseases?
Prion: rapid onset (6-12months), amyloids make vacuolation, dementia
Alzheimer’s: slow onset, shaking, dementia, amyloids make fibers
What is the risk of contracting prion disease after exposure to deer with chronic wasting disease?
Some humans may be resistant to CWD
Could not induce it in macaques which are closest to humans
5 cases were reported
What are the causes of prion diseases?
PrPc is normal and converts it to PrPsc which is a beta sheet protein and it forms amyloids
What is the mechanism and pathology of prion diseases?
PRP protein converting others into PrPsc form
What are possible tests for prion diseases?
Do by ruling out EEG - sharp wave complexes LP - meningitis CT - tumor CSF - elevation of protein 14-3-3 MRI - hockey stick test, high intensity in putamen and caudate or Pulvinar thalamic nucleus Biochem - western of PrPsc following digestion DNA seq - PRNP gene Brain biopsy - spongiform change
What does CBC and cultures show with prion diseases?
No organisms and normal CBC
What do you see on a brain autopsy with prion diseases?
Minimal inflammation
Formation of plaques
Spongiform encephalopathy
What can prions survive?
30min of boiling 60 days freezing Chemicals UV Smaller than a virus
What does PrP normally do?
Glycoprotein expressed in cell growth and maintenance
What are amyloids and how can you detect and treat them?
Fibrous protein deposits
Initiate unfolded protein response and increased vacuolation
Possiblly treat with Congo Red
What does Congo red do?
Bind to amyloids
What are the ways of transmission of prion diseases?
- canniblism
- cow meat
- hormones, skin, surgical instruments, and corneal transplants from infected people or cadavers
- mutations in the PRNP gene
- unknown
- no evidence for vertical transmission
What is Gerstmann-Strausslee-scheinker syndrome?
Familial fatal insomnia
Inherited for of mutant of PRNP gene resulting in PrPsc
Begins in adulthood and death within 3 years
What is the variant of PRNP that causes vCJD?
Codon 129 of PRNP
Where does PrPsc go?
Gut –> spleen –> lymph nodes –> peripheral nerves –> brain
