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Courtesy of Shands HealthCare Marketing and Public Affairs SIMULATED PATIENT Facilities at the University of Florida's new $60 million brain institute include a computer-driven patient simulator. One of the simulator's inventors, Michael Good (center), UF associate professor of anesthesiology, directs a team of nurses and paramedics in an emergency room drill using the simulator. BRAIN TRUST A new $60-million facility makes the University of Florida in Gainesville a national nerve center for brain and spinal cord research. The University of Florida Brain Institute, which received $38 million in federal funding, will include two of the world's strongest Magnetic Resonance Imaging machines; a neurosurgery laboratory that will allow researchers to project high-resolution brain images, including real-time dissections, onto multiple computer screens throughout the building; and laser imaging systems that will permit researchers to view immediate reactions of nerve cells to hormones and drugs. William G. Luttge , the center's director, notes that the center's strengths lie beyond its technologies. More than 270 faculty members--including researchers from fields as diverse as laser physics and gene therapy--will provide interdisciplinary focus on problems including nerve regeneration and removal of brain cancer tumors. "We really have a facultywide commitment to focus as collaborators," Luttge says. The center's technology will further encourage collaborations among clinicians and researchers. A high-speed computer network connects imaging equipment to researchers' personal computers. Access to images will eventually be available over the Internet. Current research includes embryonic spinal cord cell transplants in animals. Luttge remains optimistic that this research and other projects will lead to the ability to repair nerve cells in the future. "I don't see a lot of biological hurdles in the way," Luttge comments. CULTURING A PLACENTA Checking whether a drug can harm a fetus often results in frustration--drug package inserts typically describe results of giving disproportionately high doses to rodents, or claim "no adequate and well-controlled studies in pregnant women." The lack of an in vitro system that mimics the placenta provides one reason for this paucity of data. However, two researchers have coaxed a viable culture of the human placenta. The placenta provides "a window to the fetus," explains Douglas Kniss, an associate professor of obstetrics and gynecology at Ohio State University in Columbus. He and graduate student Teng Ma took a tissue engineering approach, and used trophoblast cells from a woman who had undergone prenatal testing in 1991 early in pregnancy. "We seed the cells in a fiber bed matrix, and they attach, proliferate, and aggregate into structures that look like villi," the fingerlike projections that form the placenta, Kniss says. Past attempts to culture a placenta failed, because those approaches used material obtained at birth, which conked out after a few days, he adds. The new method, which the researchers presented at the September American Chemical Society meeting, persists for at least four weeks. Kniss credits the interactions of biologists, physicians, and engineers with their success. "Our hope is to use this model system primarily for basic research into placental function, and secondarily for understanding the toxicology and pharmacology of new agents," Kniss says. One of the first applications will be to probe the effects of protease inhibitors on the placenta. CEREBRAL PALSY-INFECTION LINK STRENGTHENS Last year, stronger links between elevated risk of cerebral palsy (CP) to maternal infection during pregnancy shifted the view that this disorder results primarily from asphyxia during birth (J.K. Grether, K.B. Nelson, JAMA-The Journal of the American Medical Association, 278:207-11, 1997). "Anoxia accounts for a small minority of CP cases. Often there is a multiplicity of things. One problem, unless it is overwhelming, would not destroy the brain," says child neurologist Karin Nelson, of the National Institute of Neurological Disorders and Stroke. A new study by the same group adds further evidence (K. Nelson et al., Annals of Neurology, 44:665-75, October 1998). Nelson and colleagues at the California Birth Defects Monitoring Program and George Washington University Medical Center evaluated 53 protein indicators of infection in blood samples taken at birth from 31 children now older than three with spastic CP, and who were not born prematurely; they also evaluated 65 controls. The researchers examined cytokines, coagulation factors, and proteins associated with autoimmune disorders. Results were startlingly clear: five cytokines were highly elevated in the affected children compared to no elevation among the controls. Levels of coagulation factors were also higher in the affected children. Screening for these markers at birth might one day alert physicians to children at higher risk. "Diagnosis of the placenta or mother on clinical grounds assesses only the tip of the iceberg. We wanted to find more of the iceberg, specifically, indicators of inflammation," Nelson adds. NEANDERTHAL GENES A new look at old data raises questions about whether Neanderthal died out, or was absorbed into Homo sapiens. A July 1997 analysis of mitochondrial DNA (mtDNA) from a Neanderthal skeleton provided compelling evidence that these humans split from the modern line 550,000 to 690,000 years ago (M. Krings et al., Cell, 90:19-30, 1997). That report, based on the genetic material of a skeleton found in a limestone cave in Germany in 1856, showed that a hypervariable mtDNA sequence differed in 27 places between Neanderthal and modern human, compared to the five to eight average differences within modern human populations. The data suggested to some that modern humans and Neanderthals were separate species, even when co-existing 30,000 to 40,000 years ago, after which the Neanderthals vanished. The question then bacame: Did they die out, or were they absorbed into the population that would become modern humans. A recent statistical analysis from Magnus Nordborg, professor of genetics at Lund University in Sweden, rules out random mating but suggests that the mtDNA comparison is not the final word on whether the two groups interbred (M. Nordborg, The American Journal of Human Genetics, 63:1237-9, October 1998). He cites limitations of the 1997 study that include analyzing only one DNA sequence from one individual (although the work was replicated); assuming that changes in this mtDNA are meaningful; and failure to detect interbreeding from a time before the modern human population expanded exponentially. "Even if there were a lot of interbreeding, the probability is high that we would not detect it. The Neanderthal mtDNA is compatible with a scenario of no interbreeding, but doesn't rule out sensible alternatives," Nordborg concludes. PHILANTHROPY'S NEW WAVE Scientists must recognize that a flood of women and young professionals entering philanthropy may alter private, nonprofit science funding. "A new generation of philanthropists is coming of age," observes Jaleh Daie, president of the Women in Science & Technology Alliance (WiSTA) and a biology professor at the University of Wisconsin, Madison. "These new philanthropists are leading the way with strategic and innovative models of giving and using their purse power to catalyze change." To help researchers adapt to these impending changes, Daie will lead a Jan. 24 symposium titled "The Strategic Philanthropist: Is Science Riding the Wave?" at the American Association for the Advancement of Science (AAAS) annual meeting in Anaheim, Calif. The symposium will offer a window on how to support and benefit from new philanthropic models and will encourage men and women inside and outside the scientific community to direct their philanthropy in support of science and technology in its broadest sense. For additional information, contact WiSTA at (202) 737-1118. Fred H. Gage CHALLENGING FATE Conventional wisdom says that, no matter what humans do, regardless of the degree of intellectual stimulation, neurons will die by the thousands--without ever spawning new ones--as people age. Not so, says a paper in this month's Nature Medicine. (P.S. Erikson et al., Nature Medicine, 4:1313-7, November 1998) "There have been a lot of studies in lower animals, in rodents, and more recently in primates," says Fred H. Gage, senior author of the study and a professor in the laboratory of genetics at the Salk Institute of Biological Studies in La Jolla, Calif., of investigations into neurogenesis. "But there's been a resistance to the suggestion that this is possible in humans." Using the diagnostic agent bromodeoxyuridine (BrdU) and the neuron marker NeuN, Salk Institute researchers discovered cells dividing by the hundreds in the hippocampus, a tiny region of the brain implicated in learning and memory. BrdU labels dividing cells; NeuN identifies them as neurons. Because both are toxic, the Salk scientists had to use the brains of five Swedish patients who, because they were suffering from cancer of the tongue or larynx, had been given BrdU to detect tumor growth. Given the study's small sample size, scientists can, at this point, only speculate as to whether the phenomenon is a common occurrence. Future studies by several labs will look into whether cell division occurs in the cerebellum, cerebral cortex, or thalamus. "I've been receiving messages from people who are now looking back at the tissue that they have," remarks Gage. He lists several crucial questions that his and other related research has spurred: Why is the brain retaining the ability to generate cells? What controls the migration and differentiation of these cells? What controls the rate of cell division? The potential long-term implications for the treatment of brain trauma, neurodegenerative diseases, and other cell-slaying ailments are many. According to Gage, if there are cells in people's nervous systems that give rise to neurons, scientists might one day be able to direct the brain to repair itself through endogenous mechanisms.

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The Scientist Staff

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