Scientists in Japan said they had grown human liver tissue from stem cells in a first that holds promise for alleviating the critical shortage of donor organs.

Creating lab-grown tissue to replenish organs damaged by accident or disease is a Holy Grail for the pioneering field of research into the premature cells known as stem cells.

The new MERS coronavirus that has claimed dozens of lives in the Middle East does not yet have the ability to trigger a pandemic, but vigilance is needed in case it mutates, French scientists said on Friday.

"Our analysis suggests that MERS-CoV does not yet have pandemic potential," they reported online in The Lancet.

At least 11 people have been killed in an outbreak of H1N1 flu virus in northern Chile, where the rate of infection is more than six times higher than the rest of the country, authorities said Thursday.

"The average across the country is 24 patients per 100,000 residents, but in Tarapaca, in the past week, the rate was 148 patients per 100,000 residents," Medical Association president Enrique Paris said.

An environmental group said Wednesday that the caramel coloring used in Pepsi still contains a worrisome level of a carcinogen, even after the drink maker said it would change its formula.

In March, PepsiCo Inc. and Coca-Cola Co. both said they would adjust their formulas after California passed a law mandating drinks containing a certain level of carcinogens come with a cancer warning label. The changes were made for drinks sold in California when the law passed.

A Qatari man has died in a British hospital from the Middle East Respiratory Syndrome (MERS) virus which has been causing increasing alarm among world health experts, officials said Thursday.

The death brings to 43 the number of people to date who have died from the SARS-like infection, which has an extremely high mortality rate.

Human Rights Watch on Thursday called on the Greek government to repeal a regulation forcing suspected sex workers and other groups to undergo HIV testing, reintroduced last week by the country's newly appointed health minister.

"It's deeply worrying that it took the new health minister only one day to bring back a regulation that violated human rights and stigmatized vulnerable groups, and that proved counterproductive to protecting public health," Judith Sunderland, senior Western Europe researcher at the New York-based rights group, said in a statement.

In a third-floor room of a London hospital with orange and white walls draped with Tibetan prayer flags, roughly a dozen people gathered recently to perform vocal exercises and sing songs, including folk music from Ghana and Polynesia.

While the participants were drawn to the session by a fondness for music, they also had an ulterior motive for singing: to cope better with lung disease. The weekly group is led by a professional musician and is offered to people with respiratory problems including asthma, emphysema, and Chronic Obstructive Pulmonary Disorder, or COPD.

British Home Secretary Theresa May on Wednesday announced a ban on the herbal stimulant khat, going against the advice of her own experts who said such a move was disproportionate.

Khat is to be classified as a Class C drug alongside ketamine and benzodiazepines, supply and production of which is punishable by up to 14 years in jail.

A Saudi man and a woman have died from the MERS virus, raising the death toll from the SARS-like infection in the kingdom to 36, the health ministry said on Wednesday.

Three others infected with the same virus, two in Eastern Province and one in Riyadh, have been treated, the ministry said on its website.

Wales will become the first country in the United Kingdom to adopt an organ and tissue donation scheme based on presumed consent after assembly members voted in favour of a bill on Tuesday.

The opt-in system currently in place across the UK relies on people signing up to a voluntary scheme and carrying a donor card.