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Greed driving plant science
Oz wrote: writes If there is the strong posibility that the pig organ might carry viruses that are going to jump the species barrier and infect the human race, 1) People have been living with pigs for millennia. Living with pigs is one thing, transplanting their organs is another. http://www.pbs.org/wgbh/pages/frontl...ks/howbig.html .... Walid Heneine, PhD. Centers For Disease Control Does giving the pig organ human genes increase the risk of pig viruses evolving to infect us? It's an open question. .... Jonathan S. Allan, D.V.M. Department Of Virology And Immunology, Southwest Foundation For Biomedical Research The question really is "viruses," not "virus." When you think about the kinds of viruses that could be present in one species that could jump into humans, you have to think about a whole class of viruses or a whole family of viruses, not just one virus. .... But there may be many other viruses that are present -- that we don't have a handle on -- that could also be transmitted to humans, and that could potentially be even a larger problem. . . The viruses you worry about in the transplant setting are blood-borne diseases or sexually transmitted types of diseases. People argue that we've been in contact with pigs for hundreds of thousands of years; we slaughter them every day; we live next to them every day; so, they argue, if pigs had anything that could be nasty for us, we would have already gotten it. And the answer to that is, "Yes, the ones that we could easily get from them. But in a transplant setting, you may be dealing with viruses that don't normally have access to humans, ones that are blood-borne, ones that are sexually transmitted." In the transplant setting, you provide the most ideal environment by introducing a virus with the organ, overcoming all natural barriers, immunosuppressing the heck out of them. So you're creating the most ideal situation for a virus to arise. .... Hugh Auchincloss, jr M.D. FDA Subcommittee on Xenotransplantation One quality that viruses have is the ability to change; they can mutate. They can also lay dormant for long periods of time. Do these qualities of the virus give you any comfort, as it were? I don't think they give me comfort. Could the current pig endogenous retrovirus, the sequence that defines that virus, change to turn it into a more virulent or different kind of virus? The answer is yes, it could. .... Daniel R Salmon M.D. Virologist, Scripps Research Institute What we know about the family of viruses that are closely related to the virus in the pig that we're concerned about is that they all produce lymphomas and leukemias. These are cancers of the blood system What do we know so far about these pig viruses? How active and aggressive do they seem to be? What we know about these pig viruses today is that, first of all, they do infect human cells. Secondly, under certain circumstances, they can actively infect human cells. In other words, they can infect a human cell initially, replicate themselves, and spread to other human cells. So that's part of why there's a real concern. .... __________________________________________________ _________ Although people living with pigs and ducks in asia is assumed to be the cause of genetic recombination and the creation of new races of influenza virus. http://www.niaid.nih.gov/newsroom/fo...background.htm .... Where Influenza Comes From In nature, the flu virus can often be found in wild aquatic birds such as ducks and shore birds. The virus has persisted in these birds for millions of years, scientists believe, and does them no harm. But because the virus is always mutating in ways that allow it to infect the cells of a different species, it can jump from wild aquatic birds to other birds. Usually, the virus spreads to domestic ducks, and from there moves on to either pigs or chickens before infecting humans. Pigs facilitate transition of the virus from ducks to humans because pig cells have both the receptor molecules on their surfaces used by viruses that infect birds and also the receptors used by viruses that infect humans. So a pig could pick up the influenza virus from a bird, and that virus could mutate in the pig into a form infectious to humans. Recently, the virus has jumped from chickens to humans, and scientists speculate that chickens may also have the receptor used by human-type viruses. When a brand new viral strain reaches humans, individuals don't have immunity and the virus can spread quickly around the globe. This is called a flu pandemic. Pandemics can also be triggered by the reemergence of a viral strain that has not circulated for many years. Epidemics are more localized outbreaks, usually occurring yearly, caused by variants of already circulating strains. .... 2) Those doing the work are well aware of the potential problems and taking the required precautions. One thing is good people finding out potential problems, another is politicians, businessmen and imbecils in control of the precautions or thinking that someone else is taking all the precautions for you. Talidomide, Mad cow disease! Aids in the blood supply, remember? Is only when the dead start to pile up that the economic interests have a second look at the liabilities! |
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