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

Study of Daily Anti-HIV Pill Halted

A study of a daily pill to prevent HIV infection has been halted because partial results show that the drug offers no benefit to women using it, researchers say.

The findings from the clinical trial involving thousands of African women show that those taking the drug Truvada are just as likely to get HIV as women taking a placebo pill, the Associated Press reported.

The decision to halt the trial was announced Monday by Family Health International, a nonprofit group that launched the study two years ago. While no safety problems were seen with Truvada, women taking the pill were more likely to become pregnant than those taking the placebo.

"That's both a surprising finding and one that we can't readily explain" by what's currently known about the drug's effects on women using hormonal contraceptives, said Dr. Timothy Mastro of Family Health International, the AP reported.

A study released last fall found that Truvada did help prevent HIV infection in gay and bisexual men when used with prevention services such as condoms, counseling.

The leader of that study said it's difficult to understand why the drug didn't protect women against HIV infection. Blood samples may explain whether that failure is related to how faithfully women in the study took the drug, Dr. Robert M. Grant told the AP.

Truvada, made by California-based Gilead Sciences Inc., is a combination of two drugs, tenofovir and emtricitabine. It is already sold for treating HIV infection, the AP reported.

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Supreme Court Silent on Health Care Law Case

The U.S. Supreme Court made no mention Monday of a case involving Virginia's request for a swift review of the national health care law.

The case was among those scheduled for discussion during the justices' private conference Friday, but there was no notice about the case when the court convened Monday, the Associated Press reported.

There could be a number of reasons for this silence, such as a justice asking for more time to consider the case or to write a short opinion that would accompany an order.

Pending cases will be discussed again Friday.

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Remarks Deemed Offensive Cause Head of Surgeons Group to Resign

After weeks of controversy over an editorial that outraged many women in the medical field, the president-elect of the American College of Surgeons resigned his position Sunday.

Dr. Lazar Greenfield was editor in chief of Surgery News when he wrote a Valentine's Day editorial that touted the mood-enhancing effects of semen on women during unprotected sex, The New York Times reported.

His editorial referred to a study that suggested compounds in semen may have antidepressant effects on women. "So there's a deeper bond between men and women than St. Valentine would have suspected, and now we know there's a better gift for that day than chocolates," Greenfield concluded in the editorial.

Many women in the medical field were angered by the editorial, saying it reflected a macho culture in surgery. As a result, the entire issue of Surgery News was withdrawn and Greenfield resigned as editor in chief.

But the controversy continued to follow him and Greenfield said he decided to resign as president-elect of the American College of Surgeons "rather than have this remain a disruptive issue," he said in a statement sent by e-mail, The Times reported.

Greenfiled is an emeritus professor of surgery at the University of Michigan School of Medicine.

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New Anti-Fatigue Rules for Air Traffic Controllers

Longer breaks between shifts for air traffic controllers are among the new anti-fatigue rules announced by the U.S. Federal Aviation Administration following a series of incidents in which air traffic controllers fell asleep on the job.

Air traffic controllers will now have at least nine hours off between shifts instead of the current eight-hour minimum, under the new rules. In addition, controllers will not be allowed to switch shifts with another controller unless they have had at least nine hours off, and FAA managers will be working more late-night and early-morning shifts to better monitor controllers, USA Today reported.

But allowing controllers to have naps during a shift doesn't appear to be under consideration, even though some experts believe it's a good idea.

"On my watch, controllers will not be paid to take naps," Transportation Secretary Ray LaHood said on Fox News Sunday, according to USA Today. "We want to make sure they're well rested. We want to make (sure) that in the workplace there's the ability for them to do their job, but we're not going to pay controllers to be napping. We're not going to do that."

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