News Notes

For the first time, researchers at Johns Hopkins University have shown that human embryonic stem cell transplants have enabled mice with paralyzed hind limbs to get up and walk, offering hope that stem cell therapy could be a panacea for victims of lower motor diseases such as Amyotrophic lateral sclerosis (ALS, or Lou Gehrig's Disease) and spinal motor atrophy. John Gearhart, professor and director of the division of pediatric urology at the Johns Hopkins School of Medicine, explained the research at the annual course on Medical and Experimental Mammalian Genetics sponsored by the Jackson Laboratory, Bar Harbor, Maine. The studies involved paralyzing the mice by infecting them with a virus similar to poliomyelitis. Then, human stem cells are injected into the base of the spinal cord, with the majority of the cells migrating to the ventral horn. Within three months, half the animals so treated regained their ability to put their hind feet on the ground, although they proceeded with a slightly ataxic gait. Gearhart said that while this approach may also help victims of spinal cord injuries, it would not be effective in cases where the cord is transected. Gearhart added that there is still more work to be done in defining the best culture media for specific cell types, but he added, "I believe within 10 years we will be able to reprogram any cell." He said, though, "We're not there now." As for when human trials for diseases such as ALS might begin, however, researcher Douglas Kerr, a lead investigator at Johns Hopkins, was optimistic. "Under the best research circumstances," he said, "Stem cells could be used in early clinical trials within two years." --Jean McCann Understanding Bt Farmers worldwide use biologically produced insecticides--most commonly, crystalline toxins from the bacterium Bacillus thuringiensis (Bt). But until recently, the mechanism that made these insecticides effective was unknown. A study by Raffi V. Aroian and colleagues at the University of California at San Diego shed some light on that question and revealed how some species develop resistance to the toxins. Aroian's group examined one of five mutant genes found in the roundworm C. elegans that confer resistance to Cry5B, one of the Bt toxins. By comparing individuals with the mutant allele to those with the wild-type version, the researchers determined that the gene (named Bre for Bt resistance) codes for the production of galactosyltransferase, an enzyme that attaches carbohydrates to lipids and proteins in the gut. When the gene is missing or modified, galactosyltranferase is not produced and the toxin does not recognize its target organism; instead, it passes through the gut and is defecated. Aroian believes that this mechanism of resistance could be widespread: "Galatosyltransferase is an enzyme that is present in most organisms, including insects. We have a strong suspicion that resistance could develop in many species," says Aroian. "By understanding how resistance develops, we can determine how to prevent it." The researchers are investigating several of the other mutant genes but are unsure if these will reveal the same mechanism of resistance. They hope to finish their work by the end of the year. --Maria Anderson The Staying Power of CAM Therapies Complementary and alternative medicine (CAM) is here to stay, according to a recent study by researchers at the Center for Alternative Medicine Research and Education at Harvard Medical School. Surveying more than 2,000 people age 18 to 94, the responses confirm the unflagging growth of alternative therapy use over the past half-century (R.C. Kessler et al., "Long-term trends in the use of complementary and alternative medical therapies in the United States," Annals of Internal Medicine, 135:262-8, Aug. 21 2001). The study follows 50 years of trends from chiropractic and folk therapies of the 1950s to meditation and megavitamins of the health conscious '60s and '70s to the introduction of acupuncture, aromatherapy, and the explosion of herbal medicines in the '80s and '90s, and assesses that with four in 10 Americans trying such a therapy in 2000, CAM is more than just a passing fad. Though hesitant to define the psychological factors involved, Ronald Kessler, lead author and professor of health care policy at Harvard Medical School, says, "I'm sure it conspires with the fact that medications are getting more expensive, and the doctor-patient relationship is going down." But, he adds, "We know from our surveys that the people who use CAM therapies are not these nutty fringe people that gaze into crystals instead of getting their cancer cured." People use these therapies in combination with conventional methods, and when shown to be ineffective or dangerous they generally stopped. As well as implying a need for doctors to ask their patients about where else they are seeking help, "It implies," Kessler says, "a responsibility to do more research on those kinds of therapies." --Brendan A. Maher

News Notes

The Scientist Staff

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