Clinical sesh - prion proteins 09/09 Harris Flashcards Preview

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Flashcards in Clinical sesh - prion proteins 09/09 Harris Deck (23)
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1
Q

do PrP^sc proteins aggregate intracellularly or extracellularly?

A

extracellularly

2
Q

what is one key difference in the clinical manifestation of prion diseases like CJD, vs other neurodegenerative diseases due to protein misfolding, like Alzheimer’s?

A

prion diseases like CJD present late-middle age and Out of the Blue, with Rapid neurodegeneration and onset of symptoms, vs more insidious onset in Alzheimer’s

3
Q

name some symptoms of prion disease

A
dementia (loss of cognitive ability)
loss of motor control
  -ataxia
  -tremor
  -myoclonus
4
Q

what is the incubation period of prion disease

A

years, decades

5
Q

how long do symptoms of prion disease persist?

A

6 months - 5 years, death

6
Q

T/F prion diseases are fatal

A

true

7
Q

Kuru is what kind of desease

A

prion disease in cannibals

“kuru” = “shaking”

8
Q

how was the prion disease Kuru transmitted?

A

ritual cannibalism in New Guinea tribes

9
Q

why were women and children primarily affected by Kuru?

A

women and children traditionally ate the central nervous system, where pathological prion proteins were located

10
Q

Scrapie is what kind of disease

A

prion disease in sheep

11
Q

what is the penetrance of familial prion disease?

A

100%

if you inherit the gene, you will suffer

12
Q

explain the prion hypothesis

A

diseases like scrapie, mad cow, cjd, kuru are caused by modified cellular proteins that are infection in the absence of nucleic acids (DNA or RNA)
i.e. proteinaceous infection, not viral, not bacterial

13
Q

why did the prion hypothesis deviate from traditional knowledge at the time?

A

it volated the central dogma that DNA –> RNA –> protein… proteins were creating other infectious proteins without DNA or RNA

14
Q

what is PrPc and where is it usually found

A

cell surface glycoprotein usually found in neurons and glial cells

15
Q

what is the normal function of PrPsc

A

no normal function, exists in diseased nervous system only (however PrPc is a cell surface glycoprotein usually found in neurons and glial cells)

16
Q

what is the secondary structure of PrPc

A

mostly alpha helices

17
Q

what is the secondary structure of PrPsc

A

mostly beta sheets

18
Q

what is the primary symptom of Alzheimer’s disease

A

dementia

19
Q

what is an encephalopathy

A

a progressive condition of the brain and nervous system

20
Q

what is “spongiform”

A

sponge-like in appearance

21
Q

describe the neuropathology of prion disease

A

spongiform change

amyloid plaques

22
Q

TSEs, transmissible spongiform encephalopathies, are a type of…

A

prion disease

23
Q

what are the primary physical landmarks of Alzheimer’s?

A
  • extracellular Aβ neuritic plaques (disturb nerve fibers and cause degeneration)
  • intracellular tau neurofibrillary tangles