Genetics may help explain why some smokers are hooked from their first cigarette while other people seem immune to the addictive properties of tobacco, according to the second study in a month to spotlight a connection.

Researchers uncovered a variation in a nicotine-receptor gene that is far more common among smokers than in those who have the occasional cigarette, according to a report in the journal Addiction. People with the genetic mutation were also eight times more likely to have had a positive first experience with smoking, such as a pleasurable buzz that encourages further use.

The findings are particularly alarming because the same receptor has been linked to increased rates of lung cancer in previous research, according to the founder of the University of Michigan’s Nicotine Research Laboratory, Ovide Pomerleau. The gene variation helps ensure the first cigarette is pleasurable, increasing the chances of addiction and raising the risk of lung cancer, he said.

“It’s a triple whammy,” Mr. Pomerleau said in a telephone interview. “This puts the biology, genetics, behavior, and traits of addiction together with one another. In the hands of a medical geneticist, this could be used to identify families that are at extremely high risk and encourage the young people to not even experiment.”

A study released July 10 in the journal Public Library of Science found white smokers with certain gene mutations who tried cigarettes before age 17 were up to five times more likely to become addicted as those without the defect.

Prostrate Screening in Elderly Men May Cause More Harm Than Good, Task Force Says

Doctors should stop routine prostate cancer screening of men over 75 because there is more evidence of harm than benefit, a federal task force advised last week in a new blow to a much-scrutinized medical test.

The U.S. Preventive Services Task Force, which made the recommendation, reported finding evidence that the benefits of treatment based on routine screening of this age group “are small to none.” However, treatment often causes “moderate-to-substantial harms,” including erectile dysfunction and bladder control and bowel problems, the task force said.

The new guidance is the first update by the task force on prostate cancer screening since 2002. The last report on the subject from this panel of experts, which sets the nation’s primary care standards, concluded there was insufficient evidence to recommend prostate screening for men of all ages.

Centers for Disease Control To Use Gift Cards To Spur HIV Education

Desperate for a way to stop the escalating spread of HIV among young gay men, public health officials are looking to novel strategies, such as enlisting local gay opinion leaders to urge their peers to practice safe sex.

Promising signs from such a project in North Carolina led the Centers for Disease Control and Prevention to begin rolling it out on a broader scale, to more than 200 community groups. The budget is $1.5 million over a two-year period.

The idea is to give gift coupons to popular, influential men in the gay community and encourage them to talk up condom use, regular HIV testing, and other responsible actions.

It may sound frivolous, but little else has proven effective for the men most affected by the epidemic.

Last week, new figures showed still-rising HIV infections in gay and bisexual men, with about 53% of new cases in that group. Meanwhile, HIV rates among injection-drug users and heterosexuals is declining.

The CDC says it’s also committed $5 million to a five-year social marketing campaign to promote HIV testing to young black gay and bisexual men, who have been diagnosed with HIV at especially high rates.

“The CDC is committed to ensuring that its resources are going to the populations hardest hit by the epidemic,” the acting director of the CDC’s Division of HIV/AIDS Prevention, Richard Wolitski, said.

The new approaches are an encouraging sign of help, but the funding behind them doesn’t come close to raising prevention spending to the level most experts say it should be, executive director of the National Alliance of State and Territorial AIDS Directors, Julie Scofield, said.

“It’s a drop in the bucket,” she said.