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also made worse by the overdependence on AZT, a drug which is definitely carcinogenic.” A second characteristic of HIV which makes infection by it so difficult to treat is the virus's ability to enter "resting" T-cells." Such cells are particularly good places for a virus to hide because they are inactive and, therefore, ignored by the immune system. Similarly, "resting" T cells are not targeted by drugs, which in order to work also require some form of activity by either the infected cell or the virus. Since such "resting" T cells can remain dormant for years, even decades, HIV can exist undetected in infected individuals for a similar length of time. also made worse by the overdependence on AZT, a drug which is These included HIV-1 and HIV-2, Coxsackievirus B, and the definitely carcinogenic." epatitis B and C viruses.'""” What this means is that the genomes A second characteristic of HIV which makes infection by it so of such viruses include a gene that is virtually identical to that seen difficult to treat is the virus's ability to enter "resting" T-cells."* in humans, which allows them to manufacture the essential Such cells are particularly good places for a virus to hide because enzyme glutathione peroxidase. Subsequently, to prove that this they are inactive and, therefore, ignored by the immune system. apparent section of the HIV-1 genetic code really permitted it to Similarly, "resting" T cells are not targeted by drugs, which in roduce the mammalian selenoenzyme glutathione peroxidase, order to work also require some form of activity by either the Taylor and his co-workers” cloned the hypothetical HIV-1 gene infected cell or the virus. Since such "resting" T cells can remain and transfected canine kidney cells and MCF7 cells with it. In both dormant for years, even decades, HIV can exist undetected in cases, the cells given the HIV-1 gene greatly increased their infected individuals for a similar length of time. production of the selenoprotein glutathione peroxidase. This roves beyond any reasonable doubt that HIV-1 (and probably HALTING THE AIDS PANDEMIC HIV-2, Coxsackievirus B and the hepatitis B and C viruses) is Throughout recorded human history, pandemics have ravaged capable of producing glutathione peroxidase for its own purposes. the known world. Typically, millions died from infection by a More or less simultaneously, K. D. Aumann and co-workers,”' particular pathogen which then retreated, only to return later as of the Department of Biological Chemistry, University of Padova, community immunity declined. Cholera, influenza, typhoid, Italy, were studying the biochemistry of the glutathione peroxi- smallpox and bubonic plague, for example, have taken repeated dases. In three articles, they argued that glutathione peroxidase is heavy tolls of the human population." There is, however, no characterised by catalytically active selenium which forms the convincing evidence of repetitive AIDS pandemics. The current centre of a strictly conserved triad composed of selenocysteine, scourge, already threatening to overtake the devastation glutamine and tryptophan. That is, they believed that it consisted associated with the Black Death, appears to be the first. of the trace element selenium and three amino acids, namely cys- Simian immunodeficiency viruses (SIV) have been collected teine, glutamine and tryptophan. Their suggestion, it should be from 26 different species of African non-human primates. Two of _ noted, ran contrary to the conventional belief that glutathione per- these appear to have given rise to oxidase consists of selenium, cysteine, HIV-1 and HIV-2 in humans.'* That glutamine and not tryptophan but is, these human viruses evolved from glycine. simian viruses as a result of zoonotic, Regardless of the true composition cross-species transmission. A close Numerous clinical trials have of glutathione peroxidase, there is no examination of the genomes of these doubt that this enzyme contains sele- viruses seems to indicate that HIV-1 demonstrated that individuals nium. Since, as researchers at the asin ate chances Fe” | eating a high-selenium diet are iv, Gols pve coat SIVsm, a sooty mangabey relatively unlikely to develop Coxsackievirus B and the hepatitis B sverkewiv2 | @ Wide variety of cancers. enzyme, it would seem logieal to However, mankind has been in expect that infections from them close contact with chimpanzees, would peak in high-selenium regions. sooty mangabeys and other non- Interestingly, there is abundant evi- human primates for hundreds of thou- dence that the reverse is true and that sands of years. Obviously there must have been endless opportu- a high dietary selenium intake gives a great deal of immunity nities through hunting and the bushmeat trade for human exposure against all of these viruses. to simian body fluids and for the cross-species transmission of Indeed, it is believed by the author that this inability to diffuse, viruses. Why, then, did HIV only begin to infect the human pop- in areas where the population has a relatively high selenium ulation on a global scale, for the first time, in the last two decades intake, represents the Achilles heel of HIV/AIDS and currently of the 20th century? After all, the 16th to 19th centuries saw the offers the best available strategy for halting, or at least slowing, inhumanity of the slave trade, with the movement of millions of the pandemic.” West Africans to Europe, North America and elsewhere. Had In sub-Saharan Africa, Senegal stands out like a diamond in the HIV-1 or HIV-2 been endemic in West Africa at the time, these dirt. Given the widespread polygamy and unprotected promiscu- viruses would certainly have been diffused around the globe by ity in the country,””” one would expect that its mortality from both slaves and slavers. Indeed, exotic diseases were spread by AIDS would have been enormous. After all, Senegal is located in the slave trade from Africa to Europe and elsewhere; these includ- sub-Saharan Africa, close to the region where the simian immun- ed yellow fever, but they did not include AIDS." odeficiency virus (SIVcpz) is believed to have been transmitted Viruses are like all other life-forms: they thrive in specific from chimpanzees to humans on several occasions and where it physical and social environments, and not in others. The most subsequently evolved into HIV-1. However, in Dakar, Senegal's likely reason why HIV/AIDS is pandemic now is that certain major urban centre, HIV-1 prevalence among women attending changes in the environment, occurring in the latter part of the 20th antenatal clinics has remained at one per cent or less since the and early part of the 21st century, have greatly improved HIV's time that surveillance began in the mid-1980s until the present. competitive position. Similar very-low-prevalence rates are also recorded in the What these changes were can be deduced from the work of E. W. Senegalese hinterland.* Taylor and his colleagues at the University of Georgia. In the mid- Geologically, Senegal is a dried-up Cretaceous and early 1990s, these researchers discovered there was a series of viruses Eocene sea. When this d ation took place, sedimentary rocks that encoded for a selenium-dependent glutathione peroxidase. were formed from the dissolved minerals in evaporating sea eating a high-selenium diet are relatively unlikely to develop a wide variety of cancers. 28 = NEXUS Numerous clinical trials have demonstrated that individuals www.nexusmagazine.com DECEMBER 2003 — JANUARY 2004