Block E 3

Question 1

5 physical defences against viral infection

Answer 1

skin
mucus
ciliated epithelium
gastric acid
bile

Question 2

3 examples of antigen non specific antiviral response

Answer 2

interferon, cytokines (TNF, IL-1)
nk cells and macrophages
fever

Question 3

2 examples of antigen specific immune responses

Answer 3

T cell response
antibody

Question 4

immune mediators for flu like symptoms (and examples)

Answer 4

interferon
lymphokines
resp viruses, arboviruses

Question 5

immune mediators for delayed type hypersensitivity and inflammation

Answer 5

T cells
macrophages
polymorphonuclear leukocytes
enveloped viruses

Question 6

immune mediators for immune complex disease

Answer 6

antibody
complement
Hep B, rubella

Question 7

immune mediators for haemorrhagic disease

Answer 7

T cell
antibody
complement
dengue fever, measles

Question 8

immune mediators for post infection cytolysis

Answer 8

T cells
enveloped viruses (eg post measles encephalitis)

Question 9

immune mediators for immunosuppression

Answer 9

none
HIV, measles, rubella

Question 10

producer cells of a-interferon

Answer 10

leukocytes

Question 11

producer cells of b-interferon

Answer 11

fibroblasts

Question 12

producer cells of y-interferom

Answer 12

T cells
NK cells

Question 13

physical properties of a-interferon

Answer 13

acid stable
non glycosylated protein

Question 14

physical properties of b-interferon

Answer 14

acid stable
glycoprotein

Question 15

physical properties of y-interferon

Answer 15

acid-labile
glycoprotein

Question 16

3 stages of interferon induction

Answer 16

-dsRNA (virus intermediates)
-viral inhibition of cellular protein synthesis
-enveloped virus interaction with rare blood leukocyte

Question 17

4 stages of interferon mechanism of action

Answer 17

-release from intial infected cell
-INF bind to specific receptor on another cell
-INF induces antiviral state
(synthesis of protein kinase)
-stops protein synthesis that blocks viral replication

Question 18

4 basic steps in viral disease

Answer 18

-acquisition
-inhibition of infection
-incubation period
-infection of target tissue

Question 19

do abortive infections cause a virus production and what is the fate of the cell

Answer 19

no
no effect

Question 20

do transformative infections cause a virus production and what is the fate of the cell

Answer 20

no
tumour

Question 21

do cytolytic infections cause a virus production and what is the fate of the cell

Answer 21

yes
death

Question 22

do chronic (nonlytic, productive) infections cause a virus production and what is the fate of the cell

Answer 22

yes
senescence

Question 23

do latent infections cause a virus production and what is the fate of the cell

Answer 23

no
no effect

Question 24

what does the cytopathologic activity of the virus change

Answer 24

changes in cells macromolecular synthesis

Question 25

example of non specific histological changes that occur due to cytopathologic activity

Answer 25

vacuolisation

Question 26

what can be said about the tissue and infection of inapparent infections

Answer 26

infected tissue undamaged infection controlled before virus reaches target tissue

Question 27

extent of damage is ... in inapparent infections

Answer 27

below functional threshold

Question 28

5 disease and viral factors that promote transmission

Answer 28

-stability of virion in environment -transfer of virus into transmissible aerosols or secretions -asymptomatic transmission -ineffectiveness of immune response to control reoccurrence

Question 29

8 mechanisms of viral transmission

Answer 29

-aerosols -food, water -fomites (tissue, clothes) -sexual contact -birth -blood transfusion, injection, organ transplant -zoonoses (animals, insect) -genetic

Question 30

examples of risk factors with viral transmission

Answer 30

age health/nutrition/genetics immune status occupation travel history lifestyle sexual activity children

Question 31

factors with geography and season that affect seronegative (susceptible people)

Answer 31

presense of cofactors in environment habitat and season for arthropod vectors winter summer