Prion Diseases

Question 1

Rare, fatal, rapidly progressive neurodegenerative diseases that occur in humans & other animal species

Answer 1

Prion diseases

Question 2

In prion disease, a presence of _____ within the neuropil, produces a _____ appearance

Answer 2

Small vacuoles; spongiform

Question 3

The complex net of axonal, dendritic & glial branching that forms the bulk of central nervous system gray matter of the brain & in which the nerve cell bodies are embedded:

Answer 3

Neuropil

Question 4

Describe prion diseases:

Answer 4

-Rare
-Fatal
-Rapidly progressive
Neurodegenerative diseases that occur in humans & other animals

Question 5

What animal prion diseases affects cattle?

Answer 5

Bovine, spongiform encephalopathy

Question 6

What animal prion disease affects sheep & goats?

Answer 6

Scrapie

Question 7

Human prion diseases include: (5)

Answer 7

1. Kuru
2. Creutzfeldt-Jakob disease (CJD)
3. Variant Creutzfelft-Jakob disease (Variant CJD)
4. Gerstmann-Straussler-Scheinker Syndrome
5. Fatal familial insomnia (FFI)

Question 8

Fatal neurodegenerative disease of sheep:

Answer 8

Scrapie

Question 9

Scrapie is demonstrated to be a _____ disorder

Answer 9

Transmissible

Question 10

Fatal neurodegenerative disease of humans recognized since the 1920, demonstrated to be transmissible in the 1960s (humans to chimpanzees):

Answer 10

Creutzfeldt-Jakob Disease (CJD)

Question 11

What are the early symptoms of CJD?

Answer 11

-memory problems
-behavioral changes
-poor coordination
-visual disturbances

Question 12

What are the layer symptoms of CJD?

Answer 12

-dementia
-involuntary movements
-blindness
-weakness
-coma

Question 13

What is the outcome of CJD?

Answer 13

70% of people die within 1 year of diagnosis

Question 14

It was discovered during the search for the infectious agents of Scrapie & CJD, that infection agents were _____ meaning not cellular, therefore, possibly a ____

Answer 14

Filterable; virus

Question 15

When determining what the infectious material of Scrapie & CJD was, ionizing radiation did not affect transmission of Scrapie & CJD, what does this mean?

Answer 15

The infectious material did not contain DNA or RNA

Question 16

Because ionizing radiation did not affect the transmission of Scrapie & CDJ, the hypothesis of the 1960s concluded that the scrapie & CJD are caused by:

Answer 16

Solely proteins

Question 17

What term was created to describe Scrapie & CJD?

Answer 17

Prion

Question 18

What term was created to describe Scrapie & CJD,

Question 19

The term prion means:

Answer 19

Proteinaceous infection

Question 20

The cellular protein involved in prions:

Answer 20

PrP (prion protein)

Question 21

Describe endogenous Prp:

Answer 21

Normal protein in the body that is NOT an disease agent

Question 22

Endogenous Prp’s can adopt a couple of different confirmations:

Answer 22

1. Normal
2. Disease forming

Question 23

The difference between a normal PrP & a disease-causing PrP occurs at the:

Answer 23

Confirmation level

Question 24

What is significant about an endogenous PrP converting to prion form?

Answer 24

It can continue to cause other endogenous PrPs to convert to the disease causing form

Question 25

What is responsible for encoding PrP protein?

Answer 25

PRNP gene on chromosome 20

Question 26

The PrP gene displays:

Answer 26

Polymorphism

Question 27

What do we mean when we say the PrP gene displays polymorphism?

Answer 27

Variance of gene sequence which results in variance of amino acid sequence

Question 28

Describe an area in the PrP sequence that we may see polymorphism:

Answer 28

Met or Val at codon 129 of PRNP gene

Question 29

What is the occurrence of seeing Met or Val at codon 129 of the PRNP gene:

Answer 29

Met= 60% Val= 40%

Question 30

When an individual is homozygous for either Met or Val at codon 129 of the PRNP gene, what does this mean?

Answer 30

They are at increased risk of disease (CJD)

Question 31

The scrapie/prion form of Prp (PrPsc) is resistance to _____ & accumulates in ____

Answer 31

Degradation; Amyloid fibrils

Question 32

PrPc (normal form of PrP) is strongly expressed in both ____ & ____ of the CNS

Answer 32

Neurons & glial cells

Question 33

What is the function of PrPc in the CNS?

Answer 33

Appears to regulate ion channels & neurotransmitter receptors at the pre- & post-synaptic levels

Question 34

What is the median age of death for an individuals with CJD?

Answer 34

68 years

Question 35

What is the median age of death for an individual with a variant of CJD?

Answer 35

28

Question 36

What is the median duration of illness for an individual with CJD?

Answer 36

4-5 months

Question 37

What is the median duration of illness for an individual with a variant of CJD?

Answer 37

13-14 months

Question 38

What are the clinical signs & symptoms of CJD?

Answer 38

Dementia & early neurologic signs

Question 39

What are the clinical signs & symptoms of variant CJD?

Answer 39

Prominent psychiatric/behavioral symptoms; painful dysthesias; delayed neurologic signs

Question 40

Describe the accumulation of PrPSC in brain tissue in an individual with CJD compared to an individual with Variant CJD:

Answer 40

CJD: Variable accumulation Variant CJD: Marked accumulation

Question 41

What is a clinical concern of prion diseases?

Answer 41

Prions may NOT be inactivated by means of routine surgical instrument sterilization procedures

Question 42

The WOH & US CDC and Prevention, recommend that instrumentation used during prion cases must be:

Answer 42

Immediately destroyed

Question 43

Secondary to destruction of instruments use in prion cases, it is recommended that ____ & ____ be used in combination to process instruments that come into contact with high-infectivity tissues:

Answer 43

Heat & chemical decontamination

Question 44

Since the adoption of current sterilization procedures regarding prion disease instrumentation use in 1976 what have we seen?

Answer 44

No cases of iatrogenic transmission of CJD that been reported