Fetuses Can Hear Ultrasound Scans, Researchers Say
Ultrasound scans can be heard by a fetus, researchers say, a finding that is sure to surprise many physicians. There is no evidence, however, that this is harmful.
By definition, ultrasound is sound that is beyond the range of human hearing. But ultrasound probes emit their sound waves in short-duration pulses several thousand times per second.
When the pulses enter the body, they “tap” internal organs--including the ear--with frequencies comparable to the high notes on a piano, according to Dr. Mostafa Fatemi and his colleagues at the Mayo Foundation. This vibrates the eardrum, just as sound waves traveling through air would. But the sound heard by the fetus is actually more like that heard when your finger taps a spot close to your ear, which explains why it is inaudible to the mother and others.
The researchers reported last week at a meeting of the Acoustical Society of America that measurements of the sound in water indicate a sound level of 100 to 120 decibels, about that of an approaching subway train. The sound is very localized, however, so the fetus can avoid it by moving. The study helps explain the observation of physicians that fetuses move vigorously when ultrasound is directed at their heads.
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Drug’s Long-Term Benefit
to Alcoholics Questioned
A widely used drug for treating alcoholism apparently provides little benefit in helping long-term heavy drinkers to quit, according to a new government study.
The drug, naltrexone, was originally approved for treating drug addiction and was shown to be helpful in alcoholism in small studies. The drug blocks the release of chemicals that make alcoholics feel good after a drink.
In the first large study of the drug, a team led by Dr. John Krystal of the Veterans Affairs Connecticut Healthcare System studied 627 men, with an average age of 49, who had been getting drunk regularly since their early 20s. When the study began, they were drinking three days out of every four, with an average consumption of 13 drinks on those days. The patients received naltrexone for either three months or a year, or received a placebo.
All the patients received individual 12-step counseling and were encouraged to attend Alcoholics Anonymous meetings.
There was no difference among the three groups in their success at giving up drinking. All the patients went an average of 41/2 months without drinking, researchers reported in the Dec. 13 issue of the New England Journal of Medicine. Drinking declined, both in frequency and actual consumption per drinking bout, after 13 weeks and after a year. But the reduction was the same in all the groups. The researchers said the drug might still be useful for patients who are not as heavy drinkers as those in the study.
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Tongue Piercing Blamed
for Brain Abscess
A Connecticut woman suffered a near-fatal brain abscess after having her tongue pierced, according to physicians from Yale University School of Medicine.
The piercing made her tongue swollen and tender and produced a foul-tasting discharge, so she removed it, the physicians said last week. A month later, however, she began suffering from severe headaches, fever, nausea and vomiting. A CT scan showed the presence of an abscess--a bacteria- and pus-filled sac--in her brain. When the abscess was drained, it contained bacteria commonly found in the mouth.
Doctors believe the bacteria migrated from the tongue to the brain through the bloodstream. The woman received six weeks of intravenous antibiotics and made a full recovery.
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Group Therapy’s Value to Cancer Patients Studied
Group therapy sessions do not prolong life in breast cancer patients, according to a new study that contradicts results from an earlier study.
A 1989 study had suggested that such supportive therapy increased lifespan by 18 months. But recent smaller studies--and now a larger study by researchers at the University of Toronto--have not found such an effect.
Dr. Pamela J. Goodwin and her colleagues studied 235 breast cancer patients. One-third received only medical treatment, while the rest received medical treatment and attended group therapy sessions.
The researchers reported in the Dec. 13 issue of the New England Journal of Medicine that the two groups had the same life expectancy. The women receiving group therapy did report less pain and emotional distress, however. One possible explanation for the finding, experts said, is that breast cancer survival rates have increased significantly since the original study, so that group support is of less value.
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High Triglyceride Levels May Predict Stroke Risk
High levels of triglycerides are a major predictor of stroke risk, according to an Israeli study. High cholesterol, obesity and diabetes are already known to be important risk factors, but the new study is the first to address triglycerides independently.
Dr. David Tanne and his colleagues at Sheba Medical Center in Israel studied 11,177 patients with heart disease but no history of stroke, following them for six to eight years. The researchers reported in the Dec. 11 issue of Circulation: Journal of the American Heart Assn. that those with triglyceride levels above 200 milligrams per deciliter--150 mg/dl is normal--had a 30% higher risk of stroke.
In an editorial in the same journal, Dr. Dion Graybeal of the University of Texas Southwestern Medical Center said the findings might persuade doctors to begin prescribing drugs that lower triglyceride levels.
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Small Tumors Aren’t Necessarily Less Harmful
Oncologists have long assumed that smaller tumors are at an earlier--and less dangerous--stage of development, but that is not always the case, according to researchers from Duke University. The findings call into question the growing use of a technique called spiral CT scans to detect small lung cancer tumors that were presumed to be less dangerous.
Dr. Edward F. Patz Jr. and his colleagues at the Duke Comprehensive Cancer Center studied 620 men and women with primary non-small cell lung tumors that measured less than 3 centimeters (about 1.5 inches) in size. They reported in the Dec. 15 issue of the journal Cancer that they found no correlation between the size of the tumor and the stage of development.
Early detection with a spiral CT scan, they said, may have little impact on the overall outcome of the disease.
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Viagra Alternative Found
Effective in Clinical Trial
A new alternative to Viagra has been shown to be effective in a small clinical trial. The drug is apomorphine, a potent dopamine agonist (replacement) that promotes erectile function by stimulating receptors in the hypothalamus, the region of the brain that controls erectile activity. Viagra, in contrast, works at the final stages of the erectile pathway, altering the function of blood vessels in the penis.
Researchers from Nastech Pharmaceutical Co. studied 184 men with erectile dysfunction. One group received a placebo, while three other groups received varying doses of apomorphine via a nasal spray.
The company said last week that 81% of those receiving the highest dose developed an erection within 15 minutes and were able to maintain it during sex. No significant side effects were observed. Viagra is less effective and has more side effects.
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Times medical writer Thomas Maugh can be reached at thomas.maugh@latimes.com.
