Prions Flashcards
1
Q
Prions
A
- infectious protein particles
- lack nucleic acid
2
Q
Prions are extremely resistant to
A
Heat, chemicals and irradiation
3
Q
Prions cause
A
Transmissible spongiform encephalopathies (TSEs)
4
Q
Animal TSEs include
A
- scrapie in sheep
- bovine spongiform encephalopathy–> Mad cow disease
- transmissible milk encephalopathy
- chronic wasting disease in deer and elk
5
Q
Human TSE
A
- Kuru
- Crutzfield-jakob disease (CJD)
- Gerstmann-Strausller disease
- fatal familial insomnia
6
Q
Normal/native prion=
A
PrPc (predominantly alpha helix)
7
Q
Abnormal prion=
A
PrPsc (predominantly beta helix)
8
Q
Interaction between an abnormal prion w native prion leads to
A
alterations of PrPc and PrPsc and its ultimate aggregation and accumulation in tissues
9
Q
Accumulation of PrPsc in CNS cause
A
- neurological disease
- vacuolation of nervous tissue –> Spongy
10
Q
How do we get PrPsc?
A
- ingest PrPsc infectious material
- injection of PrPsc infectious material (reusable surgical instruments)
- spontaneous mutation
- spontaneous conversion of protein
11
Q
Scrapie
A
- neurological disease in adult sheep and goats
- mode of transmission; abrasions, ingestion, vertical
12
Q
Patholeogy of Scrapie
A
- PrPsc first detected in spleen and tonsils, LN
- agents spreads through fibres of autonomic nervous system to spinal cord and brain
- hair loss, itchiness, tremors of head, emaciation and death
13
Q
Diagnosis
A
- post mortem
- clinical signs
- immunohistochemistry for PrPsc
- EM to detech scrapie- associated fibrils in brain tissue
14
Q
Scrapie control
A
- not in Oz
- quarantine, prohibition of live exports from scrapie countries
15
Q
Bovine spongiform encephalopathy
A
“Mad Cow Disease”
