Originally created 03/02/00

Capsules



Viagra warnings

They tell you not to eat before surgery. Now, the American Association of Nurse Anesthetists is warning men not to take Viagra for 24 hours before an operation. Viagra, which uses nitric oxide to open blood vessels and relax muscles, can cause a patient's blood pressure to become dangerously low when combined with the effects of anesthesia and other drugs used during surgery, the nurses' group warns.

Temperature tastes

Hot and cold may mean sweet and sour to the tongue. Scientists have found that warming or cooling the tongue can conjure up taste sensations.

Scientists have known that taste nerves in the tongue fire impulses when the tongue is heated or cooled. But no one had ever shown that a person could really "taste" temperature changes.

Researchers at the Yale School of Medicine in New Haven, Conn., tested 24 people to see whether they could taste temperature changes. Twenty-one of the subjects could, and temperature changes tasted different to different people.

A common report was that warming the tip of the tongue from 68 degrees to 95 degrees Fahrenheit caused a mild sweet sensation. Cooling it to below 68 degrees tasted sour to some people, and cooling below 50 degrees tasted salty to one person.

Even though people can taste temperature in laboratory experiments, temperature doesn't seem to be noticed much in everyday life, wrote Robert Frank of the University of Cincinnati in a commentary in Nature, where the study was published. How the nervous system avoids tasting temperature on a day-to-day basis is a mystery.

Helpless laughter

Doctors have described the peculiar case of three patients who would be a standup comic's dream audience: They are often inexplicably stricken with the urge to laugh.

Each of the three has a benign tumor on the hypothalamus. The hypothalamus, a tiny structure nestled deep in the brain, is involved in many functions, including body temperature, appetite and emotion. And laughter.

In the current issue of the journal Neurology, researchers from the Austin and Repatriation Medical Center in Victoria, Australia, say that the patients suffered from giggling episodes throughout childhood. Fortunately, the feeling is usually pleasant.

Unfortunately, the tumors also cause mild seizures, although these can be controlled with medication.

Implant effects

Breast implants do not appear to affect the detection of breast cancer or a woman's survival after diagnosis, according to a new report in the journal Plastic and Reconstructive Surgery. Doctors from the University of Southern California have been monitoring more than 3,000 women who received breast implants between 1959 and 1981. Of those, 37 have since developed breast cancer. However, neither the women's severity of disease at diagnosis nor their mortality is any greater than women of the same age and race in the general population, the scientists say.

Toothy progress

Tooth decay in permanent teeth has fallen 57 percent among children over the past two decades, a new study shows. Among baby teeth, the decline is 40 percent, researchers report this month in the Journal of the American Dental Association. The numbers are based on a national, periodic health survey of Americans.

Girls galore

Older fathers and mothers are more likely to have girls, says a study of more than 25 years of birth reports. The influence of age was strongest among nonwhite parents, researchers from Exxon Biomedical Services report in the March issue of the journal Fertility and Sterility. The scientists undertook the study as part of an ongoing examination of the declining proportion of male births.

Alzheimer's link

People who grew up as part of a large family may be at higher risk of developing Alzheimer's disease, a study in the journal Neurology suggests.

The study by researchers at the University of Washington looked at 770 people older than 60 living in the Seattle area. Roughly half had signs of Alzheimer's.

Early life environments have links to heart disease, stroke and diabetes, said Victoria Moceri, who led the study. Her theory is that the early environment could have an effect on brain development that may manifest itself as symptoms of dementia in old age.