Health Highlights: Sept. 22, 2007

Mar. 23 -- Here are some of the latest health and medical news developments,compiled by editors of HealthDay:

Experimental AIDS Vaccine Fails Key Test

A trial of a vaccine designed to control AIDS has been halted after numerous participants became infected with HIV, the virus that causes the disease.

Drug maker Merck & Co. said Friday that it was stopping enrollment and vaccination of volunteers taking part in the international study, which was partly funded by the U.S. National Institutes of Health.

Merck told the Associated Press that 24 of 741 volunteers who got the vaccine in one part of the trial eventually became infected with HIV. In a comparison group of volunteers who got dummy shots, 21 of 762 participants also became infected with HIV.

The volunteers were HIV-free at the start of the trial. But they were at high risk for getting HIV. Most were homosexual men or female sex workers. They were all repeatedly counseled about how to reduce their risk of HIV infections, including use of condoms, according to Merck, the AP said.

The Merck vaccine was the first major test of a new strategy to prevent HIV infection. Initial trials to develop a vaccine tried to stimulate antibodies against the virus, but that didn't work.

The new approach -- which is also being tried by other researchers -- seeks to prod the body to produce more of key immune system cells called killer T-cells, the news service said.

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Researchers ID Hundreds of Genes Linked to Infertility

U.S. researchers say they've identified nearly 350 genes linked to female fertility, a finding that could lead to greater study of the poorly understood field of infertility.

"This study gives us a way to begin to understand the causes of female infertility," said Dr. Diego Castrillon, assistant professor of pathology at the University of Texas Southwestern Medical Center, in Dallas. "It gives us a much more complete list of candidate genes to explore. Before, we didnt even know where to look."

The new study was done with mice, but "at the molecular level, ovarian biology is very similar in mice and humans," said Castrillon, senior author of the paper that is published in the September issue of the journal Genetics.

The findings might one day allow clinicians to test whether an infertile woman has problems with a specific gene, allowing for improved diagnostic tests and individualized therapy, said Castrillon, a specialist in the diagnosis of infertility and other diseases of women.