Term
| Who wrote the famous phrase, “nothing in Biology makes sense except in the light of evolution”? |
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Definition
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Term
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Definition
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Term
| What’s the worst epidemic in human history, and how many people did it kill? |
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Definition
| Influenza; 50-100 million deaths |
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Term
| How many people has HIV so far killed and how many will it have killed by 2020? |
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Definition
25 million deaths; 90 million by 2020 |
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Term
| What percentage of deaths is AIDS currently responsible for? |
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Definition
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Term
Does AIDS kill more or fewer people than cancer, heart attack or stroke?
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Definition
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Term
| Does AIDS kill more or fewer people than tuberculosis, wars, car accidents, homicides or malaria? |
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Definition
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Term
| What region of the earth has the greatest prevalence or infection percentage of HIV in its population? |
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Definition
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Term
| What’s the HIV infection percentage in Swaziland? |
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Definition
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Term
| What’s the adult prevalence of HIV among the general population of the United States; among the homosexual adult male population in the United States? |
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Definition
0.6% among adults; homosexual interactions are most common transmission |
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Term
| What are 5 different ways of contracting HIV? |
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Definition
| Homosexual sex, needle sharing, blood transfusions, heterosexual sex, oral sex |
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Term
| Describe the difference between the route of HIV transmission in China compared to the United States |
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Definition
China: injecting drug users à blood donors à heterosexual sex
US: homosexual sex à needle sharing à heterosexual sex |
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Term
| Is it possible to curb the spread of AIDS without depending solely on drugs? |
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Definition
| Yes, reducing risky sex practices, using condoms |
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Term
| Why has the HIV infection percentage in the United States continued to increase despite our vast understanding and knowledge of the the virus? |
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Definition
| Drug therapies make people think of AIDS as a chronic illness à increased sexual practices, meth abuse à increased sexual practices |
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Term
| describe the life cycle of HIV? |
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Definition
HIV Viron enters a cell, reverse transcriptase makes a DNA copy of the HIV RNA, HIV DNA inserts into host genome, TS à TL à viral proteins, new virons bud from the host’s membrane
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Term
| What host cells receptors are necessary for HIV infection of that cell to commence? |
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Definition
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Term
| What characteristics of HIV classify it as a retrovirus? |
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Definition
Information flows from RNA à DNA à mRNA à Proteins
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Term
| What components of the host cell does the virus utilize to propogate itself? |
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Definition
Host’s RNA POL, DNA, and ribosomes
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Term
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Definition
| Virus invades and depletes Helper-T cells which are necessary for fighting other pathogens/infections. |
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Term
| Of a population of rhesus monkey that contracted SIVsm, which individuals developed AIDS and why? |
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Definition
| Macaques. Their own aggressive immune response helps spread the virus. |
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Term
| Describe one way to prevent the development of AIDS from HIV? |
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Definition
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Term
| Describe the unique phases of HIV infection in terms of the viral load and the host’s immune system response? |
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Definition
| Acute Phase – virus replicates rapidly/explodes, Chronic Phase – virus replication decreases slightly and host cells slightly recover, eventually helper T cells are overwhelmingly depleted and viral load climbs |
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Term
| What is AZT and how does it work? |
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Definition
| Azidothymidine- enzyme that interrupts and blocks reverse transcriptase by incorporating itself as a base. There is a N3 group instead of an OH group à no phosphodiester bond can be made there |
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Term
| What are the side effects of AZT treatment and why do they occur? |
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Definition
| Become sick because new cells cannot be made. Cell division stops working. |
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Term
| Why does AZT treatment ultimately lose efficacy and how long does it take? |
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Definition
HIV evolves a way (reverse transcriptase mutates)to discriminate against thyiomine and AZT. On average it takes less than a year
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Term
| How and why does HIV evolve so quickly? |
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Definition
It doesn’t have DNA error correcting enzymes, and has a high viral load population |
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Term
| Describe the 4 postulates of Darwin’s evolutionary theory via HIV/AZT. |
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Definition
1. TS errors produce mutations in the reverse transcriptase gene. Verions carrying mutant reverse transcriptase genes produce versions of the reverse transcriptase enxyme that vary in their resistance to AZT
2. The mutant virions pass their reverse transcriptase genes, thus their AZT resistance to their offspring. AZT resistance is heritable.
3. During treatment with AZT, some virions are better able to survive and reproduce than others.
4. The virions that persist in the presence of AZT are the once with mutations in their reverse transcriptase genes that confer resistance. |
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Term
| Describe 4 potential strategies for developing better treatments for HIV infection. |
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Definition
Reverse Transcriptase Inhibition, Protease Inhibition, Fusion Inhibition, Integrase Inhibition
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Term
| Why is it ironic that HIV is fatal to the host from the virus’s perspective? |
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Definition
| When the host dies, so does the virus inside the host |
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Term
| Describe the rate of divergence of HIV from the founder population to the population of cells present when the host dies (using the concept of genetic distance)? |
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Definition
Divergence is fast at first, then slows down b/c it doesn’t have the same selection pressures.
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Term
| Describe the molecular difference between HIV and HIVX4. |
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Definition
HIV uses the CCR5 receptor and the HIVX4 uses a different co-receptor than the CCR5.
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Term
| Why is HIVX4 so much more lethal than HIV? |
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Definition
It effects naive t-cells not just the helper t-cells
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Term
| If HIVX4’s is so much more successful, then why does HIV exist? |
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Definition
HIVX4 kills the host faster , it doesn’t have this projected battle and a shorter transmission period. HIVX4 cannot be transmitted.
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Term
| Aside from the short-sighted evolution concept, what other reason could explain why HIV is fatal to itself? |
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Definition
| There is a correlation between lethality and being transmitted to the host |
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Term
| Describe the interesting results from the Sydney Blood Bank Cohort? |
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Definition
A blood donor donated HIV blood, to 4 other people, 2 died of old age, and 2 developed AIDS but only after 17-18 years.
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Term
| What accounts for the slower progression to AIDS from HIV in the Sydney Blood Bank Cohort? |
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Definition
| There was a different NEF protein that allows the virus to get into the host cell which limits its damage |
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Term
| Why are people with the delta 32 mutation in the CCR5 co-receptor resistant to HIV infection? |
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Definition
| There is a mutation and the virus cannot gain access |
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Term
| Who has the delta 32 CCR5 mutation, why is this ironic, and why don’t all humans have the delta32 CCR5 mutation? |
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Definition
| Northern European populations, where HIV is lower in population. HIV is a new virus and the delta 32 mutation hasn’t had time to spread. |
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Term
| why is the delta32 CCR5 mutation so much more prevalent in Northern European human populations? |
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Definition
| provided some resistance to the bubonic plague. |
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Term
| Where did HIV come from, and how was this discovered? |
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Definition
It’s a virus derived from SIV viruses that infect primates. It came from chimpanzees and sooty mangabees. It was discovered using phylogenetic analysis, there are two groups. 2 transmissions from chimps, and 1 transmission from mangabees. Likely from butchering.
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Term
| When did SIV jump from chimpanzees to humans, and how was this discovered? |
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Definition
It happened about 60 years ago, by phylogenetic analysis
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Term
| Is it possible to design a vaccine that would provide humans immunity to HIV, and why hasn’t one been made? |
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Definition
| Yes, and no because the virus mutates too quickly. |
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