Menopause symptoms not eased by soy tablets

Taking soy supplements may not help women ease their menopause symptoms or prevent the bone changes that start at that time of life, suggests a new study from Florida.

Women who took the supplements every day for two years didn't have any improvement in their symptoms compared with those who took a soy-free placebo pill - and they suffered more hot flashes by the end of the study.

Researchers also didn't see any changes in their bone mineral density compared to women taking placebos. Low bone mineral density puts women at higher risk of osteoporosis and broken bones.

Women seeking relief from menopause symptoms have been without a clear go-to treatment since the Women's Health Initiative (WHI) study of hormone therapy reported heart and cancer risks with estrogen and progestin use.

"What prompted us to do this study was in the wake of WHI when many of our patients stopped using hormone therapy," says Dr Silvina Levis, the study's lead author from the Miller School of Medicine, University of Miami.

"Many of them had just gone to a health food store and started on soy supplements," she says.

"The study was started to try to answer a simple question: Will these soy isoflavone tablets help women with the issues they were concerned with?"

"We didn't see any protection from bone loss or any relief from menopause symptoms." After this, she adds, "maybe women will reconsider" taking soy tablets during menopause.

Stem cell research offers hope to infertile men

A team of scientists has reported producing viable sperm using the stem cells of mice in an experiment that researchers hope could one day lead to treating infertile men.

The Kyoto University researchers managed to induce mice stem cells into creating sperm precursors, which were transplanted into infertile male mice. The mice then produced sperm that was successfully used to fertilize eggs in a lab dish.

The offspring were healthy and fertile, according to a paper published online in the scientific journal Cell.

Members of the research team, led by Mitinori Saitou, say they believe their success may help in the development of infertility treatments in humans, although they say many hurdles remain.

"We have high hopes, but it's not that easy," Saitou says. "There are many difficult issues ahead in applying this to humans. But it is a first step."

Experts outside the group say it's an important first step toward infertility treatment.

"This is a very good experiment for thinking about treatment of infertile man but a very very long way," says Toshio Suda, developmental biology professor at Keio University.

Researchers learn more about starving parasites to death

Researchers in Australia are working on a technique that will allow them to starve to death parasites that are proving harder to destroy using existing drugs.

The parasite they used in the study was the Leishmania, which is transmitted by the bite of the phlebotomine sandfly. After a period of incubation, the parasite causes huge skin sores, fever, anemia and damages the spleen and liver. It affects 12 million people worldwide and has become more resistant to current drugs.

The scientists exposed the parasite to a large variety of food sources. Using highly sensitive equipment, they tracked how these nutrients were broken down and absorbed into the bodies of the parasites.

"Using this technique we found that Leishmania parasites are very dependent on the use of sugars for energy and growth. This was surprising as previous studies suggested that these parasites may be able to use a range of other nutrients for growth (such as amino acids and fats)," writes lead author Malcolm McConville, a biochemistry and molecular biology professor at the University of Melbourne.

"They are therefore far more picky than we thought and therefore more vulnerable to therapeutic attack," he adds.

The team is hoping to use this food source as a way in to attack the parasite.

"We are interested in seeing whether we can develop new drugs that inhibit parasite sugar metabolism. These drugs would not only prevent parasites from growing and infecting new tissues, but would also make them vulnerable to host immune response," McConville adds.

Reuters-AP