Saturday, November 29, 2008

Selenium may slow march of AIDS

Contact: Amitabh Avasthi
Penn State

Increasing the production of naturally occurring proteins that contain selenium in human blood cells slows down multiplication of the AIDS virus, according to biochemists.

"We have found that increasing the expression of proteins that contain selenium negatively affects the replication of HIV," said K. Sandeep Prabhu, Penn State assistant professor of immunology and molecular toxicology. "Our results suggest a reduction in viral replication by at least 10-fold."

Selenium is a micronutrient that the body needs to maintain normal metabolism. Unlike other nutrients, which bind to certain proteins and modulate the protein's activity, selenium gets incorporated into proteins in the form of an amino acid called selenocysteine.

These proteins – selenoproteins – are especially important in reducing the stress caused by an infection, thereby slowing its spread.

Upon infecting a person, the virus quickly degrades selenoproteins so that it can replicate efficiently. It is unclear just how the virus is able to silence these proteins but Prabhu and his colleagues believe that stress inflicted on cells by the rapidly dividing virus, which produces a key protein known as Tat, is the likely culprit.

Tat is one of about 14 odd proteins produced by HIV during the first stage of infection. The job of these proteins is to trigger the expression of all the other genes that the virus needs to sustain itself. In addition, Tat also plays a key role in helping the virus replicate.

One of the proteins that targets Tat is a selenoprotein known as TR1.

"Since HIV targets the selenoproteins, we thought that the logical way to deal with the virus is to increase the expression of such proteins in the body," explained Prabhu, whose team's findings are outlined this week (Nov. 28) in the Journal of Biological Chemistry.

Researchers first isolated blood cells from healthy human volunteers who did not have HIV, and infected those cells with the virus. Next, they added tiny amounts of a selenium compound – sodium selenite – into the cell culture to see the effect on viral replication.

Results from the tests indicate that the addition of selenium inhibits the replication of HIV at least 10-fold, compared to cell cultures in which no selenium is added. When the researchers selectively reduced production of the selenium containing TR1 protein, they observed a 3.5-fold increase in viral replication.

"This confirms that while increasing the expression of TR1 has a negative impact on the replication of HIV, reducing it helps the virus replicate more efficiently," explained Prabhu. He believes that TR1 works by upsetting the chemical structure of Tat, which in turn reduces the virus' ability to replicate.

"Once we fully understand the function of these selenium proteins, it will give us a handle to come up with more effective drugs," said Prabhu, whose work is partly funded by the National Institutes of Health.

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Swedish doctors predict spray-on skin

STOCKHOLM, Sweden, Nov. 28 (UPI) -- Doctors predict that spray-on skin cells will be used as a common form of sore treatment in the Swedish healthcare system within a few years.

Gunnar Kratz from Linkoping, participating in an ongoing leg wound symposium in Gothenburg, said he was keen for Sweden to introduce the method, the Swedish news agency TT said.

The treatment of leg wounds has made major advances over the past decades, with the reintroduction of maggot therapy a contributory factor. Most severe wounds do now heal, even against heavy odds.

Some wounds are simply too big for modern dressings and treatments to be fully effective. As an alternative, medical experts are currently developing skin cells that can be sprayed over the surface of a sore. And a number of studies have shown promising results.

"I believe this form of treatment will be available in the non-institutional healthcare system within the next couple of years," Kratz said.

© 2008 United Press International, Inc. All Rights Reserved.

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Report: 36 million Americans food insecure

More than 36 million Americans, including 12.4 million children, are food insecure, officials of a U.S. non-profit group said.

Feeding America, a U.S. hunger-relief organization, said the actual number of Americans forced to skip meals and survive without adequate nutrition is even greater than the report indicates because it is based on statistics from 2007.

"It is important to note that the U.S. Department of Agriculture numbers released today are 2007 figures and do not take into account the unprecedented economic crisis that our country is currently facing," Vicki Escarra, president of Feeding America said in a statement.

"Feeding America believe that this is just the beginning of a downward trend and we expect things to get worse before they get better," Escarra said.

The organization serves more than 200 food banks that provide food to the vast majority of food pantries, soup kitchens and emergency feeding centers nationwide. More than 4 million people stand in line every week for a few bags of groceries to help feed themselves and their families, Escarra said.

"Our food banks are calling us every day, telling us that demand for emergency food is higher than it has ever been in our history," Escarra said.

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Japanese car design on show

By David Millward, Transport Editor

It includes everything from futuristic concept cars to designs tailored to the peculiar needs of the Japanese internal market, with the country’s crowded cities.

“Japan Car” looks at the vehicles as “mobile cells”, based on the philosophy of Kenya Hara, one of the country’s most prominent designers.

“Although the history of cars in Japan began with an attempt to emulate the West’s automotive technology and culture, the context of Japanese lifestyles and Japan’s particular route to industrial development has given Japan’s cars their own unique characteristics and individuality,” Hara said.

Mr Hara believes that the car will be seen as a driver’s private space, with greater emphasis on internal comfort rather than speed.

“Cars are being designed from the inside out,” said Andrew Nahum, the Science Museum’s principle curator of technology.

“They are increasingly being seen as somewhere where you spend part of your life and they are your private space.”

This is reflected in some of the cars on show, like the Nissan Cube or Daihatsu Tanto – boxy affairs which could hardly be described as slender or elegant.

Some will be familiar to British eyes such as the Mazda MX-5, which is now commonplace on our roads.

Some have claimed it is little more than a copy of the classic British two-seater sports car – but with greater reliability.

But to the Japanese it is drawn from the “soil and spirit” of the country, even if it was inspired by classic cars from Britain.

Now Japanese manufacturers are at the forefront of developing new low-carbon designs, with the petrol/electric Toyota Prius hybrid now commonplace on Britain’s roads.

But others will follow and some are also on display at the museum, including the similarly powered Honda Insight hybrid, which is also on sale in the UK.

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