Scientists Pinpoint Rett Syndrome Gene
Researchers have discovered the defective gene that causes Rett Syndrome, a finding that the scientists said will make diagnosing the disease easier and someday may lead to new treatments.
Rett syndrome is a form of mental retardation that affects about one girl in every 10,000. Girls with the syndrome develop normally for the first six to 18 months of life, then stop responding to and interacting with their parents. Eventually, they lose the ability to speak, walk and purposefully use their hands, and develop repetitive motions, such as wringing their hands.
After 14 years of searching for the gene, Dr. Huda Zoghbi of the Baylor College of Medicine and colleagues at the Howard Hughes Medical Institute report the discovery in the October issue of the scientific journal Nature Genetics. They found the gene on the X chromosome, one of the two sex chromosomes. Because of the powerful effects of the defective gene and because they have only one X chromosome, boys with the defective gene die before or shortly after birth. Girls, however, have two X chromosomes and can live with a defect on one, although it produces disastrous effects.
The gene, called MeCP2, turns on and off other genes that are important during development of the brain.
Air Filters Helped at Fertility Clinic
There are lots of things that can help promote healthy pregnancies: dietary supplements, exercise, not smoking and so forth. But air filters?
Researchers in Virginia report that air filters attached to incubators in fertility clinics can significantly increase the likelihood of successful pregnancies.
Dr. Jacob Mayer of the Jones Institute for Reproductive Medicine at Eastern Virginia Medical School said the results are surprising because the institute already goes to great lengths to keep potentially harmful agents out of the air, even forbidding technicians from wearing perfume or nail polish.
The institute purchased four $2,400 filters and installed them on half the incubators in its clinic. Between October 1998 and March 1999, Mayer randomly assigned fertilized eggs to filtered or unfiltered incubators.
Mayer reported Tuesday at a San Francisco meeting of the American Society for Reproductive Medicine that 52% of women implanted with embryos from the filtered incubators became pregnant, contrasted with only 30% of those whose embryos were grown in unfiltered incubators. Thirty percent is a common success rate throughout the industry.
Wrinkle Reducer Seems to Relieve Headaches
Botulism toxin, a muscle relaxant used to smooth out wrinkles in the forehead and to stop muscle tremors, also reduces migraine headaches, according to a UCLA researcher who inadvertently stumbled onto the discovery. Dr. William J. Binder said many of his patients who received the toxin to treat wrinkles reported that their migraines disappeared or were dramatically reduced.
To test the effects, he administered the toxin to 96 patients with chronic migraines. He told a medical conference in New Orleans on Tuesday that 49 stopped having headaches and 27 others reported that the number or severity of the headaches had been cut in half. The effects persisted for several months. It’s an expensive remedy, however: The toxin costs hundreds of dollars per treatment.
Protein May Reduce AIDS Drug Resistance
Scientists at the Massachusetts Institute of Technology’s Whitehead Institute for Biomedical Research have identified a potential new class of AIDS drugs that may circumvent the problems of drug resistance. The new drugs have not yet been tested in humans, however.
Protein chemist Peter S. Kim and his colleagues report in the October issue of Cell that they have for the first time been able to stably produce key fragments of a protein called gp41 that is used by the AIDS virus to attack cells. The fragment contains a pocket that is crucial in allowing the virus to bind to the cell. Once Kim’s team was able to produce fragments with the pocket, they found small molecules that can bind to the pocket and prevent infection of cells. The potential drugs are small enough to be taken orally. Other drugs designed to prevent cellular infection, such as T-20, are so large that they must be injected into the bloodstream.
Researchers Identify Key Element in Soy
Soy is able to reduce cholesterol and blood pressure because it contains plant estrogens called isoflavones, according to researchers from Wake Forest University Baptist Medical Center. Researchers have recognized for some time that eating soy can lower cholesterol, but the actual chemicals responsible for the effect has been a mystery.
Dr. John R. Crouse III and his colleagues had patients in the study eat soy protein containing one of four differing amounts of isoflavones, ranging from 3 milligrams to 62 milligrams. (Isoflavones were extracted from the soy in the low groups.) They reported in the October Archives of Internal Medicine that the amount of cholesterol reduction was directly proportional to the isoflavone content of the soy.
Subjects who began the study with high cholesterol levels showed a 9% drop after only nine weeks on the diet. Those getting only 3 milligrams, however, showed virtually no decrease. Among women, those eating the greatest amount of isoflavones showed the greatest decrease in blood pressure as well.
Study Finds Supplement Doesn’t Help Heart
Coenzyme Q10, a supplement widely touted for people with congestive heart failure, actually provides no benefit to such patients, a Maryland researcher reported last week at a heart meeting in San Francisco.
Proponents of the supplement claim that it supplies heart cells with energy and improves their pumping efficiency.
Dr. Stephen Gottlieb enrolled 50 patients with congestive heart failure in a study in which half were given Coenzyme Q10 and half a placebo, with neither physicians nor patients knowing who received which. After six months, he found there was no difference between the two groups in how much blood their hearts pumped and how much exercise they could perform. The supplement was safe, however.
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Medical writer Thomas H. Maugh II can be reached at thomas.maugh@latimes.com.
