Many people hospitalized in intensive care for conditions like a heart attack face lasting mental deficits similar to traumatic brain injury, U.S. researchers said Wednesday, urging families to push for minimal sedation.

The problem is "very common," with a condition known as delirium affecting about three-quarters of those treated in the ICU and subsequent brain damage enduring for at least a year in up to one in three of them, said the study in the New England Journal of Medicine.

They were mystery diseases that had stumped doctors for years — adults with strange symptoms and children with neurological problems, mental slowness or muscles too weak to let them stand. Now scientists say they were able to crack a quarter of these cases by decoding the patients' genes.

Their study is the first large-scale effort to move gene sequencing out of the lab and into ordinary medical care, and it shows that high hopes for this technology are finally paying off.

Expecting twins? You probably don't need to schedule a cesarean section. Most moms can safely give birth without surgery, a big study finds.

It's the latest research to question the need for C-sections, which are done in one-third of all births in the United States and three-fourths of those involving twins. Studies increasingly are challenging long-held beliefs about cesareans, such as that women who had one need to deliver future babies the same way.

Exercise may be at least as effective as some drugs in reducing the risk of death in stroke patients or people with heart disease, a study published on Wednesday said.

Researchers from the London School of Economics, Harvard Medical School and Stanford University School of Medicine compared the findings of several studies into the effectiveness of exercise versus drugs in people with coronary heart disease, stroke patients, people with prediabetes and those with heart failure.

Only one ultrasound in nine months and no need to see the doctor or obstetrician: at first glance, Sweden's pregnancy care appears rather simplistic.

But while it may be far from the medical approach to pregnancy seen in most Western countries, where mothers-to-be have loads of doctor's appointments and tests, the Swedish system, where midwives reign supreme, has proven its merits.

Some diseases just have a bad name. But even when their commonly known labels glorify Nazi doctors or slander certain ethnic groups, old habits are hard to change, experts say.

Medical conditions, viruses and even personality quirks have long been named after places, famous athletes, pioneering doctors and literary giants.

The Chinese inventor who dreamed up the electronic cigarette in a nicotine-induced vision says that despite its global popularity, copycat versions and legal disputes mean he has battled to cash in on his creation.

"Smoking is the most unhealthy thing in people's everyday lives.... I've made a big contribution to society," said Hon Lik, 57, in a cramped office in Beijing, sending tobacco-scented smoke into the air as he puffed on a battery-powered pipe.

A new technique that coaxes an infertile woman's ovaries into producing eggs again has resulted in the birth of a baby in Japan, international scientists said Monday.

A second woman has also become pregnant using the same method, according to the study in the Proceedings of the National Academy of Sciences, a peer-reviewed U.S. journal.

The number of world hungry has dropped to one in eight people, making the goal of halving hunger by 2015 possible despite continued problems in Sub-Saharan Africa and Southern Asia, the U.N. food agency said Tuesday.

At the global level, 842 million people -- 12 percent of the world's population -- did not have enough food for an active and healthy life, down from 868 million for the period 2010 to 2012.

The global war on heroin, cocaine and cannabis is failing to stem supply, as prices of these drugs have tumbled while seizures of them have risen, according to a study published Monday.

Researchers analysed data from seven government-funded programmes that tracked the illegal drug market over more than a decade.