Exam 1 continued

Question 1

What type of viral infection has a rapid clearance from the host immune response ?

Answer 1

Acute infection

Question 2

What type of viral infection develops late, sometimes has no clinical signs, and is continuously shed ?

Answer 2

Persistent infection

Question 3

What type of viral infection is a form persistent of infection and requires reactivation ?

Answer 3

Latent infection: can be maintained restriction of protein expression, or viral and host DNA integrated

Question 4

What type of viral infections is a form of persistent infection is established if the acute infection is not cleared ?

Answer 4

Chronic infection

Question 5

What type of viral infection is a form of persistent infection with a long incubation period, and progressively becomes a lethal disease ?

Answer 5

Slow infection

Question 6

What is cytopahic/cytopathogenic effect ? (CPE)

Answer 6

Morphological damage to cells due to viral infection

Question 7

Tell me what pyknosis is…

Answer 7

cell nucleus degeneration that has the appearance of clumped chromosomes, hyperchromatin, and shrinking of the nucleus

Question 8

What type of destruction of cells is only the detachment of some, but not all cells ?

Answer 8

Subtotal destruction

Question 9

What are 8 key characteristics of CPE ?

Answer 9

cell lysis, cell rounding, cell detachment, vacuoles in cytoplasm, inclusion bodies, syncytium formation, antigenic changes in cell membrane, swelling and clumping

Question 10

Enveloped viruses are good at trigging this type of cell response that results in 4+ cells coming together to produce a large cell that is prone to premature death…

Answer 10

Syncytium (Cell fusion)

Question 11

What are found in host cells during viral infections that have unique staining properties and what do they include ?

Answer 11

Inclusion bodies. Accumulation of viral components: negri bodies= ribnonuculear proteins from rabies Degenerative changes in cells: owl’s eye from herepesvirus Cyrstalline aggregates of virions: adenovirus infections

Question 12

What are the 5 mechanisms of virus-induced cell injury and death?

Answer 12

inhibition of host-cell nucleic acid synthesis, inhibition of host cell RNA transcription, inhibition of host cell protein synthesis, interference with cell membrane function, apoptosis

Question 13

What do non-cytocidal viruses do to cells ?

Answer 13

Cause persistent infections, allow infected cells to still replicate, pathophysiologic changes, slow changes lead to death Seen with: pestivirus, arenavirus, retrovirus, paramyxovirus

Question 14

What type of viral infection stimulates a host immune response, allows for viral spread, but clinical signs are not present ?

Answer 14

Inapparent infections

Question 15

What term is used to describe the changing of a normal cell into a cancerous cell ?

Answer 15

Cell transformation

Question 16

Neoplasia…define it!

Answer 16

Leads to neoplasm, can be localized or dissmeinated

Question 17

What is the change of a normal cell into a cancerous cell called ?

Answer 17

Cell transformation

Question 18

Leads to neoplasm, and is a descriptive term used to denote abnormal tissue that is either local or disseminated.

Answer 18

Neoplasia

Question 19

You better know what this means: Oncology…

Answer 19

study of neoplasia/neoplasms

Question 20

What type of neoplasm stays localized and does not invade other tissues?

Answer 20

Benign

Question 21

This jerk of a cancer likes to invade other areas locally and systemically…what is it ?

Answer 21

Malignant neoplasm aka cancer

This process is called metastasis

Question 22

Metastasis is defined as…

Answer 22

spread of cancer cells from origin to other parts of the body.

Travel in bloodstream and lymphatics

Question 23

T/F- oncogenic viruses cause tumors

Answer 23

TRUE

Question 24

When a progenitor cell is genetically altered and has dysregulated growth…what develops ?

Question 25

What gene encodes proteins that allow for normal cellular growth and differentiation?

Answer 25

Proto-oncogene Mutation of this can INCREASE growth

Question 26

This gene keeps cell division in check, and if a mutation arises there may be no inhibition of growth. What gene am I ?

Answer 26

Tumor suppressor gene

Question 27

What 4 things do proto-onco genes code for?

Answer 27

Growth factor proteins/receptors, transcription factors, intracellular signalling proteins, signal transducers

Question 28

What are oncogenes?

Answer 28

Mutated forms of proto-oncogenes

Question 29

Tumor suppressor genes hold cell cycle at what phase?

Answer 29

G1 (yay general biology...again!)

Question 30

What 3 proteins do tumor suppresor proteins code for, and what are their functions ?

Answer 30

**Rb**-retinblastoma protein **p53**-activate DNA repair system, stops cell at G1 **p16**-blocks cycline dependent kinase --\> Rb binds to E2F --\> no cell division

Question 31

T/F- tumor suppressor genes are responsible for repair of damaged DNA (apoptosis if failure occurs)

Answer 31

TRUE adhesion proteins, metastasis are produced to prevent spread of cancer cells

Question 32

What happens to your cells if Rb decides it wants to be different and change its genes ?!

Answer 32

Tumor cell production | (regulated cell division)

Question 33

What is an important oncogenic virus ? (4)

Answer 33

Papillomavirus, polyomavirus, herpesvirus retrovirus

Question 34

What is the difference between productive infection in a permissive cell and non productive infection in a non permissive cell ?

Answer 34

Productive infection: cell lysis releasing its progeny Non productive infection: viral genome is integrated into cellular DNA

Question 35

What family do ALL oncogenic RNA viruses belong in?

Answer 35

Retroviridae

Question 36

Acutely transforming retrovirus is...

Answer 36

directly oncogenic. carry an additional v-onc insert c-onc into viral genome

Question 37

Slow/chronic transforming retrovirus is..

Answer 37

Integration into the hosts' chromosome does NOT have v-onc causes malignant tumors

Question 38

Do you wanna do a bunch of cards on Innate immunity ?!

Answer 38

No ?... I didn't either. Go review Immuno.

Question 39

What are 8 ways the virus can evade the hosts' immune system ?

Answer 39

1) Antigenic plasticity-rapid changes to viral antigen 2) Antigenic multiplicty 3) Negative cytokine regulation: virokines are homologs to cytokines and viroceptors are homologts to cytokine receptors 4) Inhibition of complement activation 5) Evasion of neutralizing antibodies 6) Latency 7) Cell-to-cell spread 8) Inhibtion of apoptosis

Question 40

What definition is used to describe the number of deaths among the clinically ill animals ?

Answer 40

Case fatality rate

Question 41

What is mortality rate ?

Answer 41

Number of animals in a population that die from a specific disease over a period of time

Question 42

What term is used to describe the number of animals that develop clinical signs specific to a virus during a defined period of time?

Answer 42

Morbidity rate

Question 43

What is incidence rate/attack rate?

Answer 43

number of new cases that occur in a population over a specified period of time

Question 44

What are the number of occurrences of disease, infection, etc. in a population called ?

Question 45

Enzootic vs. Epizootic ?

Answer 45

Enzootic: constant presence in a geographic location Epizootic: peak in disease above normal range