Up to 15 percent of men in the US have varicoceles, and the conventional wisdom is that they decrease fertility by raising the temperature of the scrotum so sperm development is impaired. However, a few recent reports have questioned this association, showing that varicocele treatment does not improve fertility. The new findings suggest that this treatment will work, provided that pretreatment sperm motility is high.

"Spermatic vein embolization is not a new treatment for varicoceles, but there is still some debate whether it should be performed" just to restore fertility, lead investigator Dr. Sebastian Flacke, from the University of Bonn in Germany, told Reuters Health.

In agreement with other reports, "our study shows that spermatic vein embolization can have a beneficial effect on sperm," he noted. "What's new about our study is that we identified sperm motility as a predictor of when this treatment is likely to improve fertility."

The findings are based on a study of 223 infertile men who had at least one varicocele and were trying to achieve a pregnancy with a healthy partner.

Spermatic vein embolization was associated with a technical success rate of over 99 percent, the report indicates. Semen analysis performed on 173 men at 3 months indicated significant improvements in sperm motility and count. A pregnancy rate of 26 percent was noted at 6-month follow-up.

As noted, high sperm motility was the only significant pre-treatment predictor of achieving pregnancy following embolization.

Flacke said that the 26-percent pregnancy rate seen in the present study is on the low end of what has been reported previously. He attributes this to the fact that many of the men in his team "were very infertile with none of them having normal-appearing sperm. So, even in men with severe infertility, this procedure offers some chance of achieving pregnancy."

To verify the fertility benefits of spermatic vein embolization in varicocele patients, Flacke called for trials incorporating an untreated control group.

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Sleep deprivation blocks brain cell production

Last Updated: 2006-11-28 14:01:00 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Sleep deprivation causes a rise in glucocorticoid levels that inhibit the formation of brain cells, also called "neurons," in a part of the brain called the hippocampus, the results of an animal study suggest.

This finding may help explain the adverse cognitive effects associated with sleep deprivation, according to the report in the early edition of the Proceedings of the National Academy of Sciences.

The hippocampus is a brain structure located under the temporal lobes, one on each side of the brain, and is needed to form fact memories of new information.

Glucocorticoids are naturally produced hormones necessary to maintain good health and are used to treat swelling and redness if the body doesn't produce enough. They are also used as part of the treatment for a number of different diseases, such as severe allergies or skin problems, asthma, or arthritis.

In the new study, Dr. Elizabeth Gould and colleagues, from Princeton University in New Jersey, show that 72 hours of sleep deprivation in rats causes a drop in hippocampal formation or "neurogenesis," which coincides with an increase in levels of corticosterone.

When corticosteroid levels were maintained at normal levels, the sleep-deprived animals no longer showed a reduction in hippocampal neurogenesis, the report indicates.

When animals were allowed to recover from sleep deprivation, normal levels of neurogenesis returned over a 2-week period, and involved a transient rise in new neuron formation. This compensatory effect did not depend on glucocorticoid levels or on restoration of normal sleep patterns.

"Although sleep is undoubtedly critical for health and may be important for cognitive function, the present evidence does not suggest that sleep itself promotes adult neurogenesis, but rather that the stressful nature of sleep deprivation exerts negative effects on the hippocampus," Gould's team concludes.

SOURCE: Proceedings of the National Academy of Science, USA 2006.

Copyright © 2006 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.