Lab scientists on Wednesday reported that for the first time they had taken skin cells from patients who had suffered heart failure and turned them into cells that could repair damaged cardiac muscle.

The technique has so far been tested on rats and it could take up to a decade of problem-solving before trials can go ahead on humans, the scientists cautioned.

Seven aid groups on Wednesday warned Western diplomats that Yemen was on the brink of a "catastrophic food crisis" and urged them to bolster efforts to salvage the situation as they meet in Riyadh for an international conference to help the nation.

"Yemen is on the brink of a catastrophic food crisis," the seven agencies which include Oxfam, CARE and Save the Children, said in a joint statement released Wednesday ahead of the "Friends of Yemen" meeting.

Children exposed to their parents' cigarette smoke are at greater risk of suffering serious cardiovascular health problems later in life, a study showed Wednesday.

The Menzies Research Institute in Tasmania collected data from a Finnish and Australian study following children first examined 20 years ago who are now aged in their mid-30s.

A simple, cheaper exam of just the lower part of the bowel can cut the risk of developing colon cancer or dying of the disease, a large federal study finds.

Many doctors recommend a more complete test — colonoscopy — but many people refuse that costly, unpleasant exam. The new study shows that the simpler test, flexible sigmoidoscopy, can be a good option. Although it may seem similar to having a mammogram on just one breast, experts say that even a partial bowel exam is better than none.

Italian doctors in March implanted the smallest ever artificial heart into a 16-month-old baby before the infant received a permanent organ donation, said the hospital that performed the operation.

"In March, the smallest artificial heart in the world was implanted at the Bambino Gesu Hospital in Rome," Antonio Amodeo, a senior hospital official, said in a statement.

Pomegranate juice has not been proven to be an effective treatment for cancer, heart disease or erectile dysfunction, U.S. regulators said Monday, calling a company's ad claims deceptive.

The U.S. Federal Trade Commission's chief administrative law judge D. Michael Chappell ruled that the company, POM Wonderful LLC, violated federal law by making deceptive claims.

More than a third of malaria drugs examined by scientists in Southeast Asia were fake, and a similar proportion analyzed in Africa were below standard, doctors warned on Tuesday.

"These findings are a wake-up call demanding a series of interventions to better define and eliminate both criminal production and poor manufacturing of antimalarial drugs," said Joel Breman of the Fogarty International Center at the US National Institutes of Health (NIH).

New lung cancer screening guidelines from three medical groups recommend annual scans but only for an older group of current or former heavy smokers.

The advice applies only to those aged 55 to 74. The risks of screening younger or older smokers or nonsmokers outweigh any benefits, according to the guidelines.

Half the nation's overweight teens have unhealthy blood pressure, cholesterol or blood sugar levels that put them at risk for future heart attacks and other cardiac problems, new federal research says.

And an even larger proportion of obese adolescents have such a risk, according to the alarming new numbers.

A cheap off-patent drug that is commonly used for arthritis could be a wonder treatment for amoebic parasites that infect 50 million people each year, 70,000 of them fatally, a study on Sunday said.

Researchers in California found that auranofin, an oral therapy for arthritis that has been around since 1985, is highly effective against the parasite Entamoeba histolytica.