brain cancer risk
Researchers have shown that a particular metabolic pathway associated with slowing aging also drives brain cancer. The pathway, known as NAD+, is overactive in a deadly form of brain cancer known as glioblastoma, according to researchers at Washington University School of Medicine. Glioblastoma is the most common and aggressive brain cancer in adults. Over 70 percent of patients die within two years of diagnosis. The study, published Dec. 5 in Proceedings of the National Academy of Sciences, suggests that inhibiting the NAD+ pathway may improve the outlook for glioblastoma patients, but also may affect other biological processes such as aging. “There’s a lot of buzz about taking NAD+ precursors for their anti-aging effects, which is based on good science,” says Dr. Albert Kim,  assistant professor of neurological surgery. “But while we didn’t directly demonstrate that taking them makes tumors grow faster, we don’t yet understand all the risks.”
Kim and colleagues showed that a high expression of an NAD+ pathway gene known as NAMPT helped cancerous stem cells survive and proliferate, fueling the growth of existing tumors. Inhibiting NAMPT, however, reduced the ability of those cells to renew themselves and made them easier to kill with radiation. “This could mean that if you suppress the pathway, the same dose of radiation may be more effective at destroying the tumor,” says Kim, who adds that it may be possible to modulate the pathway so as to suppress cancer without accelerating aging or interfering with other important processes.
depression in children
By measuring brain waves, researchers at Washington University School of Medicine have found that clinically depressed children don’t respond to rewards the same as other children. Prior research by the same group found that a reduced ability to experience joy is a key sign of depression in children. “The pleasure we derive from rewards—such as toys and gifts—motivates us to succeed and seek more rewards,” says Dr. Joan Luby, director of W.U.’s Early Emotional Development Program. “Dampening the process in early development is a serious concern because it may carry over to how a person will approach rewarding tasks later in life.”
The research involved 84 children playing a computer game that involved receiving a reward. An electroencephalogram measured electrical brain activity; while the brains of depressed children responded similarly to those of non-depressed children when points were lost, the response when points were earned and a reward was imminent was blunted. “A decreased ability to enjoy activities and play is a key risk factor. And if a child is persistently sad, irritable or less motivated, those are markers that may indicate depression,” Luby says. The findings were published in a recent issue of Journal of the American Academy of Child & Adolescent Psychiatry.
manganese dangers
A recent issue of Neurology reports that welders exposed to airborne manganese exhibit neurological problems similar to Parkinson’s disease. The findings by researchers at Washingto University School of Medicine suggest that current safety standards may not adequately protect welders from the dangers of the job. At high levels, manganese—a component of industrial processes such as welding and steelmaking—can cause manganism, a severe neurological disorder that can result in difficulty walking and speaking. “Many researchers view what’s allowable as too high, but until now, there wasn’t data to prove it,” says Dr. Brad Racette, professor of neurology and senior author of the study.
Racette and colleagues studied 886 welders at three Midwest worksites. Each participant underwent at least two clinical evaluations of motor function spaced a year or more apart. A score of six or lower was considered normal. At their first evaluation, the welders had an average score of 8.8, and 15 percent scored 15 or higher.
