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Thursday, July 23, 2009

Missing link' found in primate form of AIDS virus killing chimps

Scientists believe they have found a "missing link" in the evolution of the virus that causes AIDS. It bridges the gap between the infection that does no harm to most monkeys and the one that kills millions of people.

That link is a virus that is killing chimpanzees in the wild at a disturbingly high rate, according to a study in Thursday's journal Nature. Chimpanzees are the first primate besides man shown to get sick in the wild in significant numbers from a virus related to HIV. Chimps are also man's closest relative among primates.

And chimps are already endangered.

But the discovery of the disease killing chimps may help doctors come up with better treatments or a workable vaccine for humans, experts said.

The monkey version of the virus that causes AIDS is called simian immunodeficiency virus (SIV), but most apes and monkeys that have it show no symptoms or illness. So "if we could figure out why the monkeys don't get sick, perhaps we could apply that to people," said study lead author Beatrice Hahn, a professor of medicine at the University of Alabama at Birmingham.

The nine-year study of chimps in their natural wild habitat at Gombe National Park in Tanzania found chimps infected with SIV had a death rate 10 to 16 times higher than uninfected chimps. And necropsies of dead infected chimps showed unusually low counts of T-cell white blood proteins that are just like the levels found in humans with AIDS, Hahn said in a phone interview.

And when scientists looked at the particular strain, they found that it was the closest relative possible to the virus that first infected humans.

"From an evolutionary and epidemiological point of view, these data can be regarded as a 'missing link' in the history of the HIV pandemic," AIDS researcher Dr. Daniel Douek of the National Institute of Allergy and Infectious Diseases wrote in an email. Douek was not involved in the Nature study.

Monkeys and apes - except for chimps - seem to survive the virus because of some kind of evolutionary adaptation, probably on the cell receptors, Douek wrote. The infection of chimps is more recent so they haven't adapted, he wrote.

Hahn said chimps and people probably caught the virus the same way, by eating infected monkeys. And they both spread it the same way, through sexual activity.

Many factors are causing Africa's chimp population to dwindle, said study co-author Michael Wilson, a professor of anthropology at the University of Minnesota and former director of field research at the Jane Goodall Institute in Tanzania. Hunting, loss of habitat and disease are decreasing chimp numbers and it's hard to figure out how much of a factor SIV is, he said.

"It is a concern," Wilson said. "The last thing these chimps need is another source of mortality."

Wilson, who spent years observing chimps in Tanzania as part of the study, said that when researchers realized the virus was fatal and they knew which chimps were infected, it became hard to watch some of their activities in the wild.

He recalled wanting to warn one female chimp, "Don't mate with those guys." Wilson said. "But of course I can't do that."

source:http://www.nature.com/

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Thoughts worth thinking about

"Our subconscious minds have no sense of humor, play no jokes and cannot tell the difference between reality and an imagined thought or image. What we continually think about eventually will manifest in our lives."-Sidney Madwed



Laws alone can not secure freedom of expression; in order that every woman and man present their views without penalty, there must be spirit of tolerance in the entire population.- Albert Einstein Too often we underestimate the power of a touch, a smile, a kind word, a listening ear, an honest compliment, or the smallest act of caring, all of which have the potential to turn a life around. - Leo Buscaglia



A person's true wealth is the good he or she does in the world. - Mohammed



Our task must be to free ourselves... by widening our circle of compassion to embrace all living creatures and the whole of nature and its beauty. -Albert Einstein



The best way to find yourself, is to lose yourself in the service of others. - Ghandi



The unselfish effort to bring cheer to others will be the beginning of a happier life for ourselves. - Helen Keller



Aim for success, not perfection. Never give up your right to be wrong, because then you will lose the ability to learn new things and move forward with your life. Remember that fear always lurks behind perfectionism. Confronting your fears and allowing yourself the right to be human can, paradoxically, make yourself a happier and more productive person. - Dr. David M. Burns



Life is as dear to a mute creature as it is to man. Just as one wants happiness and fears pain, just as one wants to live and not die, so do other creatures. -His Holiness The Dalai Lama



Mankind's true moral test, its fundamental test (which lies deeply buried from view), consists of its attitude towards those who are at its mercy: animals. And in this respect mankind has suffered a fundamental debacle, a debacle so fundamental that all others stem from it. -



Milan Kundera, The Unbearable Lightness of Being



The worst sin towards our fellow creatures is not to hate them, but to be indifferent to them. That's the essence of inhumanity. -George Bernard Shaw

Ego's trick is to make us lose sight of our interdependence. That kind of ego-thought gives us a perfect justification to look out only for ourselves. But that is far from the truth. In reality we all depend on each other and we have to help each other. The husband has to help his wife, the wife has to help the husband, the mother has to help her children, and the children are supposed to help the parents too, whether they want to or not.-Gehlek Rinpoche Source: "The Best Buddhist Writing 2005 pg. 165

The hostile attitude of conquering nature ignores the basic interdependence of all things and events---that the world beyond the skin is actually an extension of our own bodies---and will end in destroying the very environment from which we emerge and upon which our whole life depends.