Hidden away from the prying eyes of crowded Hong Kong, in school toilets, karaoke bars and public parks, young people are snorting a powerful and addictive drug -- ketamine.

Cheap and abundant, with a supply flooding across the border from the mainland, abuse reached such levels in the late 2000s that the city was dubbed the ketamine capital of the world.

Around 10 people in Italy have tested positive for a SARS-like virus but have presented no symptoms and have not been quarantined, an infectious diseases specialist told the ANSA news agency on Monday.

"They have not been isolated because they are not presenting with any symptoms," Alessandro Bartoloni of the Infectious Diseases clinic at Careggi hospital in Florence was quoted as saying.

Drugmaker Sanofi is abandoning two drugs in the late stages of development after trials revealed they weren't more effective than other therapies.

One drug, iniparib, was given to lung cancer patients in combination with chemotherapy and compared to treatments of chemotherapy alone. The company said Monday iniparib did not improve the patients' survival rate.

A new drug can help advanced lung cancer patients live longer and may aid in treating other kinds of cancer, researchers said Monday.

If the initial results are confirmed in a Phase III study already underway, it would be the first treatment developed in the past decade that can improve outcomes for patients with late-stage lung cancer.

A senior health ministry official in the Democratic Republic of Congo on Monday ruled out an Ebola outbreak in the northeast of the country, after possible cases were reported by United Nations staff.

"There were six cases, including four children under five and two adults, who suffered from fever and haemorrhagic symptoms. We have carried out analysis at the INRB (National Institute of Biomedical Research) and the results are negative... It's not Ebola," Benoit Kabela Ilunga, who runs the contagious diseases department at the ministry, told Agence France Presse.

As China boomed around 200 men set out from Shuangxi's rural idyll to build its infrastructure and skyscrapers. Now lung disease from dust has killed a quarter of them and 100 more are waiting to die.

Back home amid rice paddies and forested hills, Xu Zuoqing walks outside and his face contorts in pain from the effort. As he struggles to breathe, his wife rushes over a stool so he can recuperate.

Four people have died after drinking home-made alcohol in southern Iran and 298 others were poisoned, the ISNA news agency quoted a local health official as saying on Friday.

"Nine of the victims are in a coma and have lost their vision," said Hamid Najmeddin, adding that 100 of the victims were on dialysis after drinking the alcohol on Wednesday.

Cancer researchers warned Friday that federal budget cuts enacted by the U.S. Congress could block key advances in the fight against deadly disease.

"Draconian cuts to biomedical research will slow our progress at the moment of greatest scientific potential and increasing need worldwide," Dr. Sandra Swain, president of the American Society of Clinical Oncology, said at the opening of the group's annual meeting.

Japan and South Korea suspended some imports of U.S. wheat Friday as American regulators investigated the discovery in an Oregon field of rogue wheat genetically engineered to resist Monsanto herbicide.

U.S. regulators insisted that the wheat carries no risks, but the outcome of the probe -- namely finding out whether such wheat is growing elsewhere -- could have a wider impact on world markets, with the U.S. the biggest global exporter of wheat.

General anaesthesia for the elderly boosts the risks of dementia by more than a third, according to a study by French doctors released on Friday.

Researchers led by Francois Sztark at the University of Bordeaux in southwestern France analysed data from a long-term study into cognitive decline covering 9,300 elderly people in three French cities.