Discoveries

Research Briefs

Inflammation variation
Cortisol, often called "the stress hormone," can be pro-inflammatory, anti-inflammatory, or neither, depending on its concentration in the blood. So found a recent study led by Dartmouth anesthesiologist Mark Yeager, M.D. In a variety of experiments, Yeager and his colleagues showed that baseline cortisol levels permit inflammatory immune responses, but moderate cortisol concentrations suppress inflammation and high concentrations are neither pro- nor anti-inflammatory. Cortisol regulation of human inflammation is both "dualistic" and "dynamic," wrote the researchers in the journal Dose-Response. "It evolves over time."

Adverse effects
Before 1971, millions of pregnant women took the drug diethylstilbestrol (DES), on the advice of their doctors, in hopes of preventing pregnancy complications. Instead, the drug proved dangerous for both mothers and babies. A new study coauthored by DMS's Linda Titus-Ernstoff, Ph.D., adds to the list of dangers posed by DES. Women who were exposed to it in the womb are at a higher lifetime risk of infertility, preterm delivery, early menopause, and several other adverse health outcomes, according to the analysis, which was published in the New England Journal of Medicine.

DMS geneticist Mathieu Lupien, Ph.D., recently discovered a "pioneer" factor, called PBX1, that may lead to an understanding of how breast cancer tumors become resistant to therapies.

A hole in "lifesaver" argument
It is conventional wisdom "that every screendetected breast cancer survivor has had her 'life saved' because of screening," wrote DMS's H. Gilbert Welch, M.D., and Dartmouth senior Brittney Frankel in Archives of Internal Medicine. But they concluded that of the 230,000 women a year diagnosed with breast cancer after mammography, only about 4,000 to 18,000 actually benefit from the test. Many who survive would have been treated successfully even without mammography, while thousands of others are treated unnecessarily.

Booze cues
Drinking references in song lyrics are nothing new—think Willie Nelson's "Whiskey River"—but they may be more frequent and influential for today's teens. "The average U.S. adolescent is exposed to 34 references to alcohol in popular music daily," said a paper coauthored by DMS pediatrician James Sargent, M.D. Sargent and researchers at the University of Pittsburgh found that one in five songs that U.S. adolescents listen to contains explicit references to alcohol, often a specific brand. "These alcohol brand appearances are associated commonly with a luxury life-style characterized by wealth, sex, partying, and other drugs," they wrote in the journal Addiction.

DMS's quantitative biology institute, its director Jason Moore, Ph.D., told Nature, is "training computational-biology students to speak multiple languages beyond bioinformatics."

Home truth
Too many older adults with serious mental illness reside in nursing homes when they could be living in less-restrictive settings. So suggests a study by members of the DMS Department of Psychiatry, published in the Journal of Aging and Social Policy. "The appropriateness of nursing homes for individuals with serious mental illness remains a controversial issue in long-term care policy," they wrote, "more than a decade since [a landmark Supreme Court decision], which affirmed the rights of persons with disabilities to live in their communities."

Motion potion
Getting adolescents off the couch and in motion may have lasting benefits not just for their waistlines but also for their brains. In a study conducted by a DMS neuroscientist and two students, rats that exercised regularly during adolescence demonstrated better memory function in adulthood than rats that had not. They also had higher levels of an important protein called brainderived neurotrophic factor. "Exercising during adolescence may capitalize on the peak of neural plasticity that occurs during this developmental stage," the researchers wrote in the journal Neuroscience, "and lead to more durable effects on cognitive function compared to exercising during adulthood."

DH is taking part in a clinical trial to treat stroke victims with a chemical found in bat saliva; it can be used up to nine hours after the stroke—an important benefit in a rural area.