A sperm donor in Kansas is fighting a state effort to force him to pay child support for a child conceived through artificial insemination by a lesbian couple.

Forty-six-year-old William Marotta told The Topeka Capital-Journal he's "a little scared about where this is going to go, primarily for financial reasons."

This is your brain on sugar — for real. Scientists have used imaging tests to show for the first time that fructose, a sugar that saturates the American diet, can trigger brain changes that may lead to overeating.

After drinking a fructose beverage, the brain doesn't register the feeling of being full as it does when simple glucose is consumed, researchers found.

The use of antidepressants during pregnancy is not linked to a higher overall risk of stillbirth and death in newborns, a study said Tuesday, confounding a long-held opposing view of such drugs.

The Swedish study of more than 1.6 million births in five Nordic countries included nearly 30,000 women who had filled in a prescription for an SSRI (selective serotonin reuptake inhibitor) during pregnancy.

Long journeys into deep space, including a mission to Mars, could expose astronauts to levels of cosmic radiation harmful to the brain and accelerate Alzheimer's disease, said U.S. research Monday.

The NASA-funded study involved bombarding mice with varied radiation doses, including levels comparable to what voyagers would experience during a mission to Mars, and seeing how the animals managed to recall objects or locations.

Japan's population logged a record drop in 2012, health ministry estimates showed Tuesday, highlighting concerns that an ever-dwindling pool of workers is having to pay for a growing number of pensioners.

A record low 1,033,000 babies were born last year, against 1,245,000 deaths, resulting in a net drop of 212,000 in the nation's population of about 126 million, according to figures from the ministry.

U.S. health regulators said Monday they had licensed a new treatment for multidrug-resistant tuberculosis -- the first such federal approval aimed at tackling the deadly disease in 40 years.

The Food and Drug Administration (FDA) said it was approving the drug, named Sirturo, as an alternative treatment for adults suffering from TB when two more powerful medications that are available, isoniazid and rifampicin, do not work.

Measles cases surged in Pakistan last year with hundreds of children dying of the disease, an international health body said Tuesday, as health officials said they had launched a new vaccination campaign in the affected areas to immunize hundreds of thousands of others.

Pakistan struggles with a beleaguered health care system, unsanitary conditions in many parts of the country and a lack of education about how to prevent disease. All those factors make it difficult to combat infectious diseases such as measles and polio.

Physical fitness is a way of life on the beautiful beachfront oasis of Santa Monica. From sunrise to sunset, there's huffing and puffing in the city's parks as trainers put their students through the paces of every form of exercise imaginable.

All along the 420 acres of greenery paralleling the Pacific Ocean are groups of a dozen or more people furiously pumping iron, doing sit-ups, stepping on and off little benches and stretching on mats. Some flex their muscles with weight machines tied by big rubber bands to pretty much anything that's anchored to the ground.

Blood clots like the one that Secretary of State Hillary Rodham Clinton is being treated for following her recent concussion can occur for a host of reasons. How serious a clot is depends on where it is and why it formed. A Clinton aide would not say where hers is located.

WHAT THEY ARE: Blood pools and thickens into a clot after an injury or because of a heart problem, clogged arteries or other condition. Clots also can break off and travel to another part of the body.

Philippine officials Monday reported more injuries from fireworks as the emergency services braced for a night of thunderous and sometimes deadly merrymaking to usher in the new year.

Injuries linked to firecrackers have risen to 186 since the Christmas weekend, including 33 with eye injuries and six victims who had limbs amputated, the health department announced.