This breakthrough should give a much-needed boost to the efficiency of some forms of gene therapy, help track and treat viral disease and evolution, improve the efficiency of vaccines, and ultimately allow health care professionals track the movement of viral infections within the body. Specifically, the new method should make it easier to track and treat infectious diseases such as HIV/AIDS, influenza, hepatitis C, and dengue fever. And because viruses can also be used to introduce biotechnology drugs and replacement genes, and act as vaccines, this research should lead to new treatments for cancer, cardiovascular, metabolic and inherited disorders.

"This technology should provide a new tool for the treatment of many diseases," said Brian Salmons, one of scientists who co-authored the study. "Even if you are working with a virus that is unknown or poorly characterized, it is still possible to modify or paint it. This is very interesting for emerging diseases."

In the article, Salmons and colleagues explain how they mixed purified proteins (glycosylphophatidylinositol anchor proteins) with lipid membranes to make it possible to bind these proteins to the outer "skin" (the lipid envelope) of viruses. Even with the new paint job, the viruses remained infectious. While the experiment only involved one type of protein and two types of viral vectors, Salmons says the technique could be expanded and used to apply "paint" made up of other proteins, dyes, and a variety of unique markers.

"Biology and art converge daily: people paint their nails, color their hair, and tattoo their skin," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Now this convergence has entered a new dimension as painted viruses permit scientists to track, cure and prevent disease."

faseb/

A pattern of low vitamin B6 status also surfaced in menstruating women who reported using oral contraceptives but who were no longer using them at the time of the NHANES survey. Among women in this sub-group who were not taking vitamin B6 supplements, 40 percent demonstrated plasma PLP blood levels below the cut-off for vitamin B6 inadequacy. Morris says, that although these results are somewhat surprising, the link between oral contraceptive use and vitamin B6 deficiency remains unclear. "The vitamin could be stored elsewhere in the bodies of the oral contraceptive users, or in a different form, since our study only examined plasma PLP."

To further support their findings, Morris and colleagues measured homocysteine levels in the blood and compared them against the plasma PLP measures. Homocysteine is an amino acid that can accumulate in the blood if vitamin B6 levels are too low. Though study participants using oral contraceptives at the time of the survey did not demonstrate elevated homocysteine levels, the homocysteine concentrations of former users were significantly higher than those of women who had never used oral contraceptives. Morris says this could mean that oral contraceptive use has an effect on vitamin B6 status that is masked during use by acute effects of the exposure.

Because the study shows association and not causation, Morris stresses that further research is necessary to determine whether the RDA for vitamin B6 is high enough. "We have identified populations with a high prevalence of apparently inadequate vitamin B status," Morris says. "However, it is important to recognize that signs of deficiency are not seen at plasma PLP concentrations of 20 nmol/L and that dietary assessment is imperfect."

According to the National Institutes of Health (NIH), vitamin B6 deficiency is rare in the United States, but it can cause a form of anemia similar to iron deficiency anemia. Vitamin B6 is widely distributed in the American diet, and baked potatoes, bananas, 100 percent fortified cereals and chicken are particularly good sources. Morris says, "The question our study raises is whether, due to aging, genetics, or exposures, some population subgroups need supplements to achieve the current biochemical definition of adequate status."

tufts/