RESEARCH STUDY SHEDS LIGHT ON HOW ANESTHESIA WORKS A Duke University School of Medicine team has discovered part of the answer to a 170-year-old question: why exactly does general anesthesia work? In a study published online in Neuron, a team led by Fan Wang, PhD, Morris N. Broad Distinguished Professor of Neurobiology, found that several general anesthesia drugs knock you out by hijacking the neural circuitry that makes you fall sleep. The finding is one of the first to suggest a role for hormones in general anesthesia and provides valuable insights for generating newer drugs that could put people to sleep with fewer side effects. When graduate student Li-Feng Jiang-Xie and Luping Yin, PhD, a postdoctoral fellow in the Wang lab, examined mice that had been placed under general anesthesia, they found a Fan Wang cluster of actively firing neurons in a tiny brain region called the supraoptic nucleus, which releases large amounts of hormones into the bloodstream.
A macrophage cell
Researchers Uncover Pathway for Breast Tumor Recurrence
When the researchers switched on the cells, the animals fell into a deep slumber called slow wave sleep, typically associated with unconsciousness. When the research team killed off the cells, the mice continued to move around, unable to fall asleep.
A team of Duke Cancer Institute researchers has filled in critical details about how breast cancer can recur long after apparently successful treatment.
STUDY CONFIRMS EFFECTIVENESS OF NONINVASIVE CARDIAC SCANS
Senior author James V. Alvarez, PhD, assistant professor in the Department of Pharmacology and Cancer Biology, said small reservoirs of treatment-resistant cells can persist after treatment, often going undetected because there are too few of them to show up in scans.
One-year follow-up results show that a new, non-invasive technology to evaluate heart pain provided a reliable way to identify which patients had dangerous artery blockages, according to a study co-led by the Duke Clinical Research Institute.
In findings published online in eLife, using mouse models, the team was able to locate the residual cancer cells. Alvarez and colleagues found that these residual tumor cells lay low and, over time, switch on signaling proteins called cytokines that communicate with immune cells.
The findings, reported at an American College of Cardiology meeting, suggest that fractional flow reserve CT (FFR-CT) scans are effective in helping doctors determine which patients need more aggressive treatments.
Responding immune cells rush to the tumor sites. One type of these immune cells are macrophages, which deposit a form of collagen that has been shown to be important for dormant cells to wake up and grow again. The next step, researchers said, is to test whether currently available drugs that inhibit macrophages can delay or prevent recurrence.
Trouble Managing Money May Hint at Dementia Trouble managing money in aging adults can be a harbinger of dementia and, according to Duke research in The Journal of Prevention of Alzheimer’s Disease, could be correlated to protein deposits built up in the brain. Senior author P. Murali Doraiswamy, MBBS,
Lead author Manesh Patel, MD, HS’97-’01, ’02-’06, chief of the Division of Cardiology at Duke University School of Medicine, and colleagues analyzed data from more than 5,000 patients who under-
professor of psychiatry and geriatrics, said the findings are based on 243 adults ages 55 to 90 participating in a longitudinal study called the Alzheimer’s Disease Neuroimaging Initiative, which included tests of financial skills and brain scans to reveal protein buildup of beta-amyloid plaques. Testing revealed that specific financial skills declined with age and at the earliest stages of mild
went FFR-CT scans for clinically suspected coronary artery disease. In patients with moderate-to-severe coronary artery disease, a negative FFR-CT was associated with a low one-year risk of a major cardiac event such as heart attack or death compared to patients with a positive FFR-CT. memory impairment. The scientists found the more extensive the amyloid plaques were, the worse that person’s ability to understand and apply basic financial concepts or complete tasks such as calculating an account balance. Duke researcher Sierra Tolbert, the study’s lead author, said the findings suggest that financial capacity assessments could also help doctors track a person’s cognitive function over time. DukeMed ALUMNI NEWS • 7
