Lecture 18 - Prion Diseases

Question 1

What are prions consist of?

Answer 1

pathogenic isoform of a normal host protein, contain no nucleic acid | basically = a normal host protein undergoes a conformational change = pathogenic functions | protein aggregates, microbial and infectious

Question 2

What is the conversion of PrPc into PrPsc due to?

Answer 2

conformational change (alpha helix into beta sheets)

Question 3

What is the end result of constant PrPc conversions into PrPsc’s?

Answer 3

long aggregates of PrPsc’s (amyloid fibrils = polymerized proteins)

Question 4

What is the gene that encodes for PrPc?

Answer 4

PRNP

Question 5

What is the most common prion disease?

Answer 5

CJD (Creutzfeldt-Jakob Disease)

Question 6

What percentage accounts CJD for most of human prion disease?

Answer 6

~85%

Question 7

How many cases worldwide does CJD occur?

Answer 7

1 of 1MIL cases

Question 8

What type of occurence is CJD? (familial or sporadic?)

Answer 8

sporadic, rarely familial

Question 9

What is the age of onset for CJD? Gender?

Answer 9

55-65y/o both men and women

Question 10

How does CJD occur with the conversion of the normal PrPc protein? What triggers this conversion?

Answer 10

spontaneous conversion of PrPc; constant refolding and polymerization of PrPc into PrPsc = disease

Question 11

How may one be inoculated with PrPsc directly into central nervous system? (iatrogenic disease)

Answer 11

via transplants or cadaver hormones or contaminated surgical instruments

Question 12

What is the incubation time of sporadic CJD and iatrogenic disease?

Answer 12

sporadic = unknown; iatrogenically = mean~18 months

Question 13

What is the only diagnostic test for CJD?

Answer 13

brain biopsy

Question 14

What are the neuropathological changes of CJD?

Answer 14

spongiform vacuolation | neuoronal degeneration | glial proliferation

Question 15

What is a variant of CJD called?

Answer 15

“mad cow disease”

Question 16

What is mad cow disease?

Answer 16

known as bovine spongiform encephalopathy (BSE)

Question 17

What type of transmission is “mad cow disease”?

Answer 17

bovine to human transmission = zoonotic

Question 18

How can one get mad cow disease?

Answer 18

consuming contaminated meat

Question 19

What is CJD?

Answer 19

sporadic prion disease via host proteins

Question 20

What is an exogenous prion?

Answer 20

outside of host and moves in

Question 21

What is an endogenous prion?

Answer 21

host proteins that mutates causing sporadic diseases

Question 22

What disease does CJD mimic?

Answer 22

other neurological diseases

Question 23

What are 5 symptoms of CJD?

Answer 23

behavior variances, ataxia, myoclonis, dementia

Question 24

What is the trend of the progression of CJD disease?

Answer 24

hockey-stick = disease initially progresses on a straight line and then curves exponentially/rapidly to

Question 25

What type of treatment is available for CJD?

Answer 25

supportive treatment

Question 26

How fatal is CJD?

Answer 26

Always fatal, within a year

Question 27

How many years does it take for CJD symptoms to manifest?

Answer 27

8-12 years

Question 28

Which body systems/organs are mainly affected by CJD?

Answer 28

brain/neurological systems

Question 29

What damage is caused to the patient due to CJD?

Answer 29

loss of memory, motor control, dementia