Two million children under five die each year in central and western Africa, accounting for almost a third of all deaths worldwide in that age range, the U.N. children's agency said Sunday. 

Progress in reducing child mortality has not affected the overall number of deaths because of "enormous" population growth, said Manuel Fontaine, UNICEF's director for the region. 

Scientists said Sunday they may have unraveled how chronic stress leads to heart attack and stroke: triggering overproduction of disease-fighting white blood cells which can be harmful in excess.

Surplus cells clump together on the inner walls of arteries, restricting blood flow and encouraging the formation of clots that block circulation or break off and travel to another part of the body.

A California study out Monday found that pregnant women who lived near farms where pesticides are applied had a two-thirds higher risk of having children with autism. 

The findings in the journal Environmental Health Perspectives examine the association between living near commercial pesticide applications and having offspring with autism, but do not show cause-and-effect.

The recent rapid spread of Ebola in three countries in West Africa has come in part because efforts to contain the deadly virus have been relaxed, Pierre Formenty, a World Health Organisation specialist, told Agence France Presse on Saturday.

A sharp rise in new HIV infections in the Middle East and North Africa is a worrying trend, despite some positive developments, UNAIDS chief Michel Sidibe told Agence France Presse on Friday.

While the epidemic remains very "concentrated" within the region, with homosexuals, sex workers, migrants and drug addicts comprising the vast majority of cases, the Arab world has seen a dramatic increase in new cases in recent years.

Sierra Leone, one of three neighboring west African countries facing an Ebola epidemic, has stepped up measures to fight the highly contagious and deadly disease, the health minister has said.

Miatta Kargbo said Thursday that the number of registered cases of hemorrhagic fever had risen to 246. Of these, 103 were confirmed to be Ebola and 26 had died.

Once doomed to a life of darkness, dozens of people stricken by retinal diseases are rediscovering a world of light as scientists push ahead on cures for blindness.

Already, bionic retinas enable blind people to "see" sidewalks, doorways and even oversized text while gene therapy has allowed a small boy to put away his white cane and take up Little League baseball.

Japanese cosmetics firm Kanebo is to offer interim compensation payments to 4,000 people who suffered skin blotches after using its popular whitening creams, a company spokeswoman said Friday.

The figure represents more than a quarter of the 15,000 complaints from users in Japan of 54 products containing a chemical called "Rhododenol", which were the subject of recalls last year affecting millions of items.

The government's top drug abuse experts are struggling to find ways to expand use of a medicine that is considered the best therapy for treating heroin and painkiller addiction.

Sen. Carl Levin of Michigan on Wednesday pressed officials from the White House, the National Institute of Drug Abuse and other agencies to increase access to buprenorphine, a medication which helps control drug cravings and withdrawal symptoms. It remains underused a decade after its launch.

A rare set of genetic mutations found in fewer than one percent of the population may cut the risk of heart disease by 40 percent, researchers said Wednesday.

The findings in the New England Journal of Medicine show how certain flaws in a gene called APOC3 work to reduce a certain type of fat found in blood, known as triglycerides.