ALS 6

Question 1

virus

Answer 1

obligate intracellular parasite

genome made of DNA and RNA

Question 2

prophylaxis

Answer 2

preventing the disease before the etiologic agent is acquired by vaccination or by giving drug before the infection

Question 3

therapy

Answer 3

treatment of the disease when the host is infected by the virus

Question 4

analogue substrate definition

Answer 4

substrate of the enzyme with chemical modifications that does not allows dissociation of the substrate to the enzyme
the substrate is locked into the active site

Question 5

substrate analogue uses

Answer 5

prevent virus DNA replication by blocking the chain addition of DNA or RNA synthesis

Question 6

acyclovir

Answer 6

chain terminator that locks -OH group, no phosphodiester bonds are formed

Question 7

why acyclovir not kill us?

Answer 7

activated only inside virus infected cells
ACV to ACVMP by phosphorylation
ACVMP to ACVTP by cellular enzymes
ACVTP has higher affinity to viral DNA polymerase than host

Question 8

characteristics of a drug

Answer 8

effective and specific to the target viral function
easy to administer
effective against most variants of the influenza virus
few sides effects

Question 9

classes of drugs used against influenza

Answer 9

prevent virus out of endosome
target RNA dependent viral polymerase
target neuraminidase for viral particles release

Question 10

amantidine

Answer 10

sits in the M2 protein ion channels that protonates the virus and prevent proton entry

Question 11

amantidine resistance

Answer 11

single point mutation in the M2 protein (S3IN)
drug does not bind anymore
low cost to fitness of the virus

Question 12

H3N2

Answer 12

circulating virus resistant to amantidine

Question 13

H5N1

Answer 13

resistant due to poultry overuse

Question 14

pH1N1

Answer 14

swine flu emerged carrying S3IN

Question 15

baloxivir

Answer 15

inhibits polymerase acidic endonuclease

Question 16

baloxivir resistance

Answer 16

single point mutation in the PAI38T common in H3N2 virus

Question 17

relenza

Answer 17

higher avidity for enzyme, goes in but cannot come out therefore the enzyme cannot turnover

Question 18

tamiflu

Answer 18

same effect as relenza but available orally

Question 19

neurominidase function

Answer 19

cleaves viral molecules made by infected cells to be released into the circulation

Question 20

neurominidase inhibitor

Answer 20

prevent cleavage of the viral molecules into the circulation, being therefore tethered into the cell host resulting in no spread or replication

Question 21

effects of HIV anti-virals

Answer 21

fusion inhibitors with the cell membrane

reverse transcriptase inhibitor

Question 22

combination therapy

Answer 22

use of multiple drugs at the same time to combat mutation of a single gene that confers resistance