Notebook

BASIC ADVOCATE: Maryland's Rita Colwell plans to advocate more basic science funding as the next NSF deputy director. On January 8, President Clinton announced his intent to nominate Rita R. Colwell as deputy director of the National Science Foundation. Colwell, currently the president of the University of Maryland Biotechnology Institute, says that if her nomination is confirmed, she will use the position to push for more research dollars for basic science. She remains unfazed by the limits the balanced budget agreement places on available federal research funds. "Congress understands the value of science," she asserts. "I'm very optimistic." Colwell says she plans to draw on her experiences gained from serving on the National Science Board in 1983-89 to administer NSF programs. "I worked hard to learn as much as I could about the other areas of science," she recalls. "I'm extremely interested in furthering all the basic sciences and have a keen interest as well in interdisciplinary sciences." Colwell also served as president of the American Association for the Advancement of Science in 1995-96. The Senate must still confirm the president's nomination before the House votes on it-a process that usually takes months. Colwell would succeed Anne C. Petersen, who left the position in September 1996 and is now senior vice president for programs at the W.K. Kellogg Foundation in Battle Creek, Mich. TWILIGHT OF THE OXYGENATE: Myron Mehlman believes the use of MTBE as an additive in gasoline is on the way out. Environmentalists, petroleum refiners, and politicians in California have joined together in calling for the removal of the controversial oxygenate methyl tertiary butyl ether (MTBE) from gasoline. At a December 8 hearing, California Secretary of Environmental Protection Peter M. Rooney urged passage of federal legislation that would exempt California refiners from laws that require using MTBE. Several days earlier, San Francisco-based Chevron Corp. also called on Congress to pass the legislation. Under federal clean air laws, regions of the state must reformulate gasoline to include MTBE, which is thought to reduce emissions and smog. MTBE is classified by the Environmental Protection Agency (EPA) as a possible carcinogen; at levels below those permitted by environmental regulations, MTBE can render water supplies unusable owing to its turpentine-like taste and odor. While maintaining that MTBE is not a public health threat if handled safely, Chevron believes MTBE may not be as effective as initially thought for reducing automobile emissions and smog. Myron A. Mehlman, an adjunct professor at Robert Wood Johnson Medical School in Piscataway, N.J., argues MTBE is a clear and serious public health threat. "I've seen hundreds of cases of illness in individuals exposed to even minute, supposedly safe levels of MTBE," he observes. A former toxicologist for the Fairfax, Va.-based Mobil Corp., Mehlman says MTBE is known to cause severe headaches and skin rashes in individuals exposed to concentrations well below those permitted by EPA regulations (M.A. Mehlman, International Journal of Occupational Medicine and Toxicology, 4[2]:219-36, 1995). Mehlman, a leader in the movement to ban MTBE, was fired from Mobil after he informed a subsidiary in Japan that their gasoline contained dangerous levels of benzene. He later won more than $7 million in a judgment against Mobil for wrongful dismissal (T.W. Durso, The Scientist, Sept. 2, 1996, page 1).S. Bunk, The Scientist, Nov. 10, 1997, page 1), the realpolitik in New York is about money and technology. That's the word from Derek Link, director of federal affairs at the New York City-based Gay Men's Health Crisis (GMHC). A major AIDS service agency and influential lobbying group, GMHC recently changed its stance from opposition to support of surveillance of HIV infection in New York, which currently has no such system. According to Link, the money issue arises because New York has no for-profit hospitals, which means reimbursement rates are set by the state. Hospitals therefore could be offered an incentive to institute an HIV reporting system, especially one that includes the privacy measure of a unique identifier (UI) number that encodes each infected person's name. Maryland, the only other state with no for-profit hospitals, already uses UIs to keep track of HIV infection. New York uses UIs for women who have abortions and for hospital discharge orders, but Link says non-hospital laboratories that do HIV tests don't have the capability or the full patient records to generate UIs. Those problems are being addressed now, he adds. But assuming that names of HIV-infected people will be encrypted on computers and that printouts with names will be kept secure, why bother with UIs? Assume nothing, Link suggests. "In America, we have an unregulated free market for medical information. I can go out and buy your medical records for $400." PET PROJECT: Elaine Ostrander of the Fred Hutchinson Cancer Research Center and colleagues have developed a framework map of the canine genome. Canis familiaris may be a gene mapper's best friend. The distinctiveness of the 300 or so dog breeds provides geneticists with ready-made, highly inbred groups within which to assign genetic markers to observable traits. Such associations are the beginnings of a genome map. Elaine Ostrander, an associate member of the clinical division at the Fred Hutchinson Cancer Research Center in Seattle, and her coworkers, along with Gustavo Aguirre, Gregory Acland, and Kunal Ray at the James A. Baker Institute for Animal Health at the Cornell College of Veterinary Medicine, reported in a December paper (C.S. Mellersh et al., Genomics, 46:317-25, 1997) a framework map of the canine genome. The work reflects a two-year collaboration. "We ran the markers, and the Cornell group provided the dog families," says Ostrander. The collection of 150 four-base microsatellite repeats covers most of the dog's 38 chromosomes. The number of repeats varies at particular chromosomal locations in different breeds, providing a set of genetic markers to map genes. The repeats were mapped in 17 three-generation dog pedigrees. Another dog genome project is headed by Jasper Rine, a professor of genetics at the University of California, Berkeley. "The map is very generic and applies to all breeds," says Ostrander. "All dogs are similar enough so that the primers we used to amplify the microsatellite repeats worked on them all. They would even work on coyotes and wolves." The framework map will speed the location and description of specific genes. This should eventually provide diagnostic tests to help breeders identify carriers of the more than 350 inherited dog diseases and to aid researchers studying disorders common to canines and humans. Late in December, the International AIDS Vaccine Initiative (IAVI), a nonprofit advocacy and development group based in New York and Washington, D.C., announced funding for three projects for development of an HIV vaccine (M.E. Watanabe, The Scientist, Nov. 10, 1997, page 1). IAVI, which was begun as part of the Rockefeller Foundation, focused its funding efforts "on some of the more applied areas of vaccine development, as well as concepts that companies are not pursuing," says the group's scientific director, Margaret Johnston. Two of the three awards went for research on live attenuated vaccines. This area "needed more attention because no company was going to pursue [it]," says Johnston. Ronald Desrosiers of the New England Regional Primate Research Center/Harvard Medical School was granted $32,934 to devise a study on the safety of the live attenuated vaccine approach. John Mills, director of the Macfarlane Burnet Centre for Medical Research, Fairfield, Victoria, Australia, was awarded up to $415,500 over two years to manufacture and study a simian immunodeficiency virus (SIV) DNA with a deletion similar to one seen in HIV obtained from eight infected, asymptomatic Australians. The group will look at the DNA clone's infectivity and immunizing effects on macaques. The third grant, $494,108 to two Boston researchers-Norman Letvin of Beth Israel Deaconess Medical Center in Boston and Joseph Sodroski of the Dana Farber Cancer Research Institute-was awarded for production of a pathogenic SIV/HIV hybrid for research purposes. Researchers at Mount Sinai School of Medicine, Columbia University, and the National Institutes of Health have discovered that chimpanzee brains have an asymmetry previously thought to be unique to humans. In 94 percent of the chimpanzee brains studied, the planum temporale (PT) of the left hemisphere was significantly larger than that of the right hemisphere. These findings, reported in a paper appearing in the January 9 issue of Science (P.J. Gannon et al., Science, 279:220-2, 1998), throw into question the long-standing belief that an enlarged PT serves to facilitate language only in humans. According to coauthor Ralph Holloway, a professor of anthropology at Columbia, it's possible that chimpanzee field studies simply haven't revealed the full extent of the animals' verbal, nonverbal, and gestural communication. Another possibility: The common ancestor of chimpanzees and humans also had the feature, but only humans-after branching off from other primates 6 million to 8 million years ago-co-opted the trait for verbal communication. A third theory holds that the region is not involved in language in either chimpanzees or humans, but instead has a related function that has yet to be identified. "We would really like to do some PET [positron emission tomography] studies with somewhat sedated chimps," relates Halloway. "We'd also like to increase the sample size and maybe . . . do some sectioning and some staining, and cell counts to find out if there are differences in the number of dendrites between left and right [hemispheres]." What makes meat smell like meat? Molecular biologists at Columbia University have made inroads toward answering such questions. The researchers, whose findings were reported in the January 9 issue of Science (H. Zhao et al., Science, 279:237-42, 1998), linked the chemical octanal, which smells like meat, with the proteins in the human nose that detect it. The 1,000 known olfactory receptors in the epithelium, the tissue lining the nasal cavity, are capable of recognizing some 10,000 chemical odors. They accomplish this feat, at least in part, with numerous mucus-coated fibers, which contain the receptor proteins. Those receptors recognize different chemicals and transmit that information to the brain, which perceives the chemical as an odor. Using a disabled adenovirus as a vector, the team introduced the gene that codes for a rat olfactory receptor, rat 17, into rat olfactory neurons. By increasing the occurrence of rat 17 tenfold, scientists could easily detect the electrical activity that indicated a response to a certain odor (in this case, octanal). Although the work may have limited clinical significance, coauthor Stuart Firestein, an associate professor of biological sciences at Columbia, believes that such research provides insight into chemical pathways throughout the body. "The olfactory system has been an excellent model system" for understanding signal transduction, the way in which a molecule triggers an electrical signal in the brain, he says. In the next year or so, Firestein and his team plan to identify 20 to 30 more receptor genes and the odors that they code for. NATURALLY MAN-MADE: From left, LOEX researchers Raymond Tabbé, Lucie Germain, and François Auger display a sample of the first completely organic man-made human blood vessels. A research team from the Laboratoire d'Angiogenese Experimentale (LOEX) of the H(tm)pital du Saint-Sacrement in Quebec City has developed a new method for engineering completely organic human blood vessels. Transplanted blood vessels that lack synthetic components are less likely to be rejected by the transplantee and are less likely to cause friction with biological body parts. With a burst strength of more than 2,000 mm Hg, these were the first man-made organic blood vessels to have sufficient mechanical strength (at least 120 mm Hg) to survive transplantation. The procedure was described in the January issue of FASEB Journal (N. L'Heureux et al., FASEB J., 12:47-56, 1998): Researchers collected human vascular smooth muscle cells in umbilical cords and adult skins and cultured them with ascorbic acid to produce a cohesive cellular sheet. They wrapped this sheet, and a second one composed of human fibroblasts, around a tubular support. After the cells had matured, the support was removed. The vessels' grafting potential was then studied in a canine model. "What we want to do now is to use this system to produce other tissues, such as skin," says coauthor Lucie Germain, LOEX scientific coordinator and an assistant professor of surgery at the University of Laval. The team also intends to do a long-term study using vessels constructed with animal rather than human cells to prevent short-term rejection. According to Germain, the blood vessels are primarily designed for use in small arteries such as the lower leg or in the coronary. She hopes to carry out human clinical trials in the leg within the next five years.

Notebook

The Scientist Staff

Feb 1, 1998

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