week 2. Antiviral, antifungal, intro to parasites Flashcards
(190 cards)
what was the first antiretrovural drug produced and when?
AZT in 1987
explain the progression of HIV after infection?
you get primary infection –> where there is a rapid rise in viral load with a stark decrease in CD4 account.
However the immune system responds and there is a clinical latency where there the viral load is in balance.
However after some time the level of viral load increase while the CD4 count reduces –> opportunistic infection occurs
what are the two types of Virus?
ones based on RNA and ones with DNA
viruses that cause acute infection what are they based on?
RNA –> short lasting
give examples of acute infection caused by virus
Influenza, measles, mumps, hepatitis A virus
what are chronic infection based on?
DNA –> long lasting –> more stable and theredfore last a long time
what are the two types of chronic infection by a virus?
latent and persistant
give example of chronic latent virus’s?
Herpes simplex, Cytomegalovirus
give example of persistant virus?
HIV, Hepatitis B virus, Hepatitis C virus
what is a characteristic of persistant virus?
it replicates all the time
how does HIV convert its RNA to DNA?
using reverse transcriptase
what type of genetic information does Hep C have?
purerly RNA
how does Hep C overcome the immune system and cause chronic infection?
it affects the liver and therefore evades the immune system and constantly evolving –> beating the immune system
will you 100% die from hep B/C if you have it
no
what does a virus consist of?
Nucleic acid (DNA or RNA) Protein (coat - structural, enzymes-non-structural) \+/- Lipid envelope
HIV is Obligate intracellular parasites. What does this mean?
it cannot reproduce outside a host –> needs intracellular resources
what is important about envelope structural proteins of HIV?
it is what allows HIV to invade cells
what is the sequence of viral replication?
1) Virus attachment to cell (via receptor)
2) Cell Entry –> find the cell they can enter without harming it
3) Virus Uncoating ready for replication
4) Early proteins produced – viral enzymes
5) Replication
6) Late transcription/translation – viral structural proteins
7) Virus assembly
8) Virus release
9) Some virus kill the cell by lysis but not all do this and go and affect other cells
what do virus’s encode and why are they important for treatment?
viruses encode unique proteins that are vital for virus replication and infectivity –> antiviral drugs target this for molecular inhibition
what are the different types of polymerases involving VIrus’s?
DNA to DNA –>Eukaryotes , DNA viruses
DNA to RNA –> Eukaryotes ,DNA viruses
RNA to RNA–> RNA viruses
RNA to DNA –> Retroviruses (HIV), Hepatitis B virus
what is azidothymidine?
Nucleoside Reverse Transcriptase Inhibitor (NRTI
what does AZT do?
it inhibits reverse transcriptase in HIV and other retroviruses
what was AZT first used for?
as a cancer drug but was to toxic
what year was AZT used as a HIV treatment?
1985