Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

Scientists Aim to Make Human Sperm, Eggs from Stem Cells

A team of U.S. scientists says their goal is to use embryonic stem cells to create human sperm for reproduction within two years and eggs within five years.

They said they were "reinvigorated" by the success of Kyoto University researchers in Japan who used mice stem cells to create eggs, which were fertilized to produce baby mice, BBC Newsreported.

"We've been mostly working on the human system to do the same things -- to make mature eggs and mature sperm in a dish," Dr. Renee Pera, of Stanford University in California, explained.

Achieving their goal could help improve understanding about embryos and the reproductive process and eventually provide new options for infertile couples, BBC Newsreported.

About 15 percent of reproductive-aged couples worldwide are infertile.


Soda Vending Machines to Display Calorie Counts

Some soft drink makers are introducing new vending machines that display calorie counts to consumers.

The information will be on the buttons of the Coke, Pepsi and Dr. Pepper machines, which will also remind consumers that they can choose a low-calorie drink. The new machines will be introduced in Chicago and San Antonio municipal buildings in 2013 before being distributed nationally, the Associated Pressreported.

Monday's announcement comes ahead of proposed new rules expected as early as next year that would require restaurant chains and vending machines to post calorie information.

"This would be an important step forward," said Mike Jacobson, executive director for the Center for Science in the Public Interest, which promotes safe food and nutrition. "Currently, people don't think about calories when they go up to a vending machine. Having the calories right on the button will help them make choices," he told the AP.


Stem Cell Researchers Receive Nobel Prize

This year's Nobel Prize in physiology or medicine was awarded to two researchers for their work showing that mature, specialized cells can be reprogrammed into stem cells.

The findings by British researcher John Gurdon and Japanese researcher Shinya Yamanaka is being used by scientists to try to find ways to create replacement tissues for treating diseases such as diabetes and Parkinson's, and for laboratory research studying the causes of diseases, the Associated Pressreported.

In announcing the award Monday, the prize committee said the two researchers' work "revolutionized our understanding of how cells and organisms develop."

In 1962, Gurdon showed that the DNA from specialized cells of frogs, such as skin or intestinal cells, could be used to generate new tadpoles. The findings showed that DNA still had its ability to drive the formation of all cells of the body, the APreported.

In 2006, Yamanaka showed that a relatively simple process could turn mature cells back into primitive cells, which in turn could be coaxed into becoming different kinds of mature cells.