Lab Report: Health, Science and Medicine

By Alice Park Thursday, July 22, 2010
    • John Mcconnico / Bloomberg via Getty Images

    A lab technician at Novo Nordisk conducts in vitro research in Malov, Denmark

    AIDS PREVENTION
    Short of a Vaccine, New Hope for an Anti-HIV Gel
    For the first time, AIDs researchers have reported success with an HIV-prevention tool that can be controlled by women: a vaginal gel containing the antiretroviral drug tenofovir. Women account for nearly half of all new HIV infections each year yet have scarce options for protection. They rely on condoms or practice abstinence — strategies that require cooperation from often unwilling partners.

    That could soon change. In a preliminary study of 889 women in South Africa, the gel, which contains 1% tenofovir in an antimicrobial solution, reduced HIV infection by 39% over 2½ years compared with a placebo; in women who used the gel most faithfully before and after intercourse, it cut infection risk by 54%. What's more, it halved the chances of contracting the genital-herpes virus, another risk factor for HIV.

    The gel isn't the first of its kind. But unlike previous, failed versions of vaginal microbicides, which attempted to either neutralize HIV on contact or create a physical barrier between the virus and healthy cells, the new formulation incorporates a potent anti-HIV drug that appears to block infection more effectively.

    REPRODUCTIVE HEALTH
    Gauging Cancer Risks in IVF Babies
    Many infertile couples who turn to in vitro fertilization (IVF) to start a family a sk the same question: Is it dangerous for my child's health?

    Since 1978 — when Louise Brown, the first test-tube baby, was born — 3.5 million infants have been conceived in the lab. So researchers now have sufficient data to examine whether the procedure has any long-term impact on IVF children's health and development. Indeed, studies have shown that in vitro babies experience more health issues, including birth defects and heart and respiratory problems, than their naturally conceived counterparts.

    On July 19, in the first analysis of its kind, researchers at Lund University in Sweden reported that IVF infants also have a 42% greater risk of childhood cancers compared with other babies; most of the malignancies occurred in the first three years. But the authors say the overall risk of childhood cancer is small, and even the higher odds in IVF babies translated into a tiny absolute increase in cancer cases. And when the authors adjusted for the effect of the parents' infertility, the association between IVF and cancer disappeared. So researchers speculate that the bump in cancer risk was most likely related to the reproductive issues that led parents to IVF and didn't stem from the procedure itself.

    FROM THE LABS
    Flu Shot in a Patch
    Those scary needle jabs may soon be a thing of the past. Researchers have designed a tiny patch embedded with 100 dissolving microneedles that deliver flu vaccine painlessly into the skin. Mice inoculated against influenza with the patch showed stronger immune responses to the virus than those that received traditional flu shots.

    Stroke, Straight Up?
    Just one alcoholic drink can double the risk of stroke during the hour after it's consumed, a new study found. Beer, wine or liquor can make blood platelets stickier and raise blood pressure, which may promote the clots that cause stroke. But the authors didn't balance this risk against alcohol's potential health benefits, particularly for the heart, so they aren't suggesting you abandon the bar just yet.

    BE STILL, BEATING HEART
    Former Vice President Dick Cheney has been left without a pulse, thanks to a ventricular assist device (VAD) doctors implanted to treat his heart failure. (VADs keep blood flowing continuously instead of pumping it; hence the elimination of a pulse.) Originally used to bridge patients to a heart transplant, VADs are sustaining patients longer and longer and even allowing some to avoid transplant.

    DATA SET

    50s Age at which PTSD rates peak in women, compared with the early 40s in men

    29% Percentage of teens who started smoking after visiting stores with cigarette ads, compared with 18% of teen smokers who went to stores without them

    Sources: Annals of General Psychiatry; AP; Institute of Food Technologists annual meeting; Nature Medicine; Pediatrics (2); Science and XVIII International AIDS Conference; Stroke