Health Highlights: Dec. 4, 2012

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

Duchess of Cambridge Hospitalized With Severe Morning Sickness

The Duchess of Cambridge has been hospitalized with a severe type of morning sickness and is expected to remain in hospital for several days and to require a period of rest after she is released home, according to a statement released Monday by St. James's Palace.

The duchess, whose pregnancy was just announced, has hyperemesis gravidarum, a potentially dangerous form of morning sickness that involves vomiting so severe that no food or liquid can be kept down, the Associated Press reported.

This type of morning sickness is believed to affect about one in 50 pregnant women. It tends to occur more often in young women, those who are pregnant for the first time, nonsmokers, and women expecting multiple babies. Fewer than one percent of women with hyperemesis gravidarum require hospitalization.

The cause of the condition isn't known, but doctors suspect it may be linked to hormonal changes or nutritional problems.

"It's not unusual for pregnant women to get morning sickness, but when it gets to the point where you're dehydrated, losing weight or vomiting so much you begin to build up (toxic) products in your blood, that's a concern," Dr. Kecia Gaither, director of maternal fetal medicine at Brookdale University and Medical Center in New York, told the AP.

Women hospitalized with hyperemesis gravidarum typically receive nutritional supplements and are given fluids intravenously to treat dehydration. The condition usually subsides by the second trimester and the rest of the duchesses' pregnancy "could be entirely uneventful," Gaither said.

If hyperemesis gravidarum is diagnosed and treated early, there are no long-term effects for either the mother or child, according to doctors. Left untreated, the mother could be at risk for developing neurological problems, such as seizures, or for early delivery, the AP reported.

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New Alzheimer's Drug Begins Clinical Trial

The first combined mid- and late-stage study of a new type of drug designed to slow mental and functional decline in Alzheimer's patients was announced Monday by Merck & Co.

The 78-week trial involves a BACE inhibitor called MK-8931. It's meant to limit production of beta amyloid protein, the main component of brain damaging amyloid plaques believed to be the most likely cause of Alzheimer's, the Associated Press reported.

The first phase will involve safety testing of the drug in about 200 patients. It will then expand to include as many as 1,700 patients and will test three different doses of the drug, compared with a dummy pill.

Previous research showed that MK-8931 blocked formation of nearly all the toxic amyloid plaques.

"No one's ever done that before," Darryle Schoepp, Merck's head of neuroscience research, told the AP. "If (amyloid) plaques are the cause, the medicine will work."