MicroBio 160 1st Edition Lecture 20 Outline of Current Lecture I Strange Diseases II AIDS III Does HIV cause AIDS IV Peter Duesberg and AIDS Dissidents V Koch s Postulate VI HIV 1 and HIV 2 VII Origins of HIV VIII How Did HIV Spread into Humans IX HIV Infection X What Lead to the Current HIV Epidemic Current Lecture Exclusively limited to severely immunosuppressed patients Homosexual Pneumocystis pneumonia Abnormalities of in vitro cellular immune function Strange Diseases Kaposi s Sarcoma KS rare form of relatively benign cancer that tends to occur in older people March 1981 8 cases of aggressive KS occurred amongst young gay men in New York Increase in of cases of a rare lung infection Pneumocystis carinii pneumonia PCP in CA NY AIDS The Early Years A 1981 memo from the CDC director requests the NCI to collaborate with the CDC on studies of Kaposi s sarcoma The strange occurrences of this disease were considered important enough it was suggested that the CDC and NCI work together The story Unfolds April 22 1984 Dr Mason said he believes he knows the cause of AIDS These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute April 23 1984 Margaret Heckler said Robert Gallo has isolated the cause of AIDS Heckler vaccine against aids in about 2 years AIDS Activism in Early 1980 s US politicians did not want to acknowledge HIV AIDS nor fund any research on the Gay Man s Disease Ronald Reagan came out several times saying that it is the gay man s disease isn t it a way to cure it What is AIDS Acquired Immune Deficiency Syndrome Acquired means you can get infected with it not inherited different from cancer because you can t inherit it Immune Deficiency means a weakness in the body s system that fights diseases Syndrome means a group of symptoms that make up a disease individuals might not have all of the symptoms o The term AIDS refers to an advanced stage of HIV infection when the immune system has sustained substantial damage Not everyone who has HIV infection develops AIDS Does HIV cause AIDS HIV is the virus which causes the fatal disease of the immune system There are several critics who say AIDS is not caused by HIV infection Peter Duesberg and AIDS Dissidents Proposed hypothesis that the various American and European diseases identified as AIDS are brought on by the long term consumption of recreational drugs and or AZT life style is causing AIDS Immune system breakdown in Africa can be explained by malnutrition poor drinking water and infection overload so many other infections and other types that this is what causes the infection immune system breaks down Retroviruses like HIV must be harmless to survive because after reverse transcription from RNA to DNA they depend on cell division to replicate Koch s Postulate Observe the microorganisms in the sick host Grow the microorganism in pure culture Inoculate the microbes into a healthy susceptible host and cause symptoms in the host Isolate the microbe in pure culture Problems people don t like to do research on humans o If you try to infect our closest relatives to HIV you can t prove it Does HIV really cause AIDS Associations of someone s blood direct correlation between the amount of HIV in your system and how fast you transition to AIDS Plasma RNA concentration copies mL of blood Proportion of patients who developed AIDS within 6 years 500 5 4 501 3 000 16 6 3 001 10 000 31 7 10 001 30 000 55 2 30 000 80 HIV isolated from virtually every patient with AIDS has been cultured or confirmed by molecular techniques PCR Accidental exposure to HIV in lab workers resulted in development of AIDS no other risk factors present Didn t do anything else in their lifestyle that could have caused this Animal models of human AIDS HIV is the only factor that predicts whether a person will develop AIDS disease found in Individuals from diverse backgrounds HIV 1 and HIV 2 1984 researchers discovered the primary causative viral agent the human immunodeficiency virus type 1 HIV 1 In 1986 a second type of HIV called HIV 2 was isolated from AIDS patients in West Africa Both HIV 1 and HIV 2 have the same modes of transmission and are associated with similar opportunistic infections and AIDS In persons infected with HIV 2 immunodeficiency seems to develop more slowly and tend to be milder HIV 2 infected individuals are less infectious early in the course of infection HIV 1 and HIV 2 also differ in geographic patterns of infection the US has few reported HIV 2 cases 1990 HIV origin discovered February 1999 a University of Alabama group found a type of SIVcpz that was almost identical to HIV 1 The strain was identified in a frozen sample taken from a sub group of chimpanzees once common in west central Africa Researchers claimed this sample proved that chimpanzees were the source of HIV 1 The virus at some point crossed species from chimps to humans Theory wild chimps simultaneously infected with 2 different SIV recombined to form a third virus that could be passed on to other chimps and was capable of infecting humans and causing AIDS The Origins of HIV SIV infected red capped mangabeys These monkeys were infected with two different strains of SIV Scientists believe that chimps became infected with both strains of SIV after they hunted and killed the two smaller species of monkey SIV infected greater spot nosed monkey The two different strains of SIV recombined to create the SIVpcz that so closely resembled HIV How did HIV spread into Humans The Hunter Theory SIVcpz chimpanzee was transferred to humans as a result of chimps being killed and eaten or their blood getting into cuts or wounds on the hunter The Oral Polio Vaccine OPV theory virus was transferred through polio vaccine o Kidney cells taken from local chimps infected with SIVcpz used to develop vaccine o However February 2000 the Wistar Institute tested old vial of polio vaccine no HIV or chimpanzee SIV o AND Macaque monkey kidney cells were used for OPV not cpz The Contaminated Needle Theory African healthcare professionals reused needles could have transferred HIV from hunters to population The Colonialism Theory harsh labor camps lack of food poor sanitation weakened immune system could lead to HIV if SIV infected chimp was eaten The Conspiracy Theory HIV is man made as bioweapon mainly to wipe out minorities and homosexuals o Ignores the clear link between SIV and HIV or the fact that the virus
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