Inside this issueCover storiesNIH selects the School of Medicine for new clinical research initiativeTop asthma researcher is new leader of internal medicineGlaucoma specialist is named chair of ophthalmologyPeopleSchool of Medicine alumnus is honored with Lasker AwardExpert on insulin action is winner of Keck Young Scholars awardYale welcomes new leader of medical developmentLifelines: Priya JamidarOut & aboutAwards & honorsScienceYale launches new stem cell research programThrowing new light on cellular networksProtein sleuths' lab works around the clockAdvances: When lifting weights, keep your heart in mind | How cold sore viruses play hide-and-seek | Nicotine's addictive grip on the brain | An early start on the road to reasonAn eye for scienceGrants & contracts 
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AdvancesHealth and science news from YaleWhen lifting weights, keep your heart in mind
Many fitness buffs favor strenuous weight lifting to sculpt their bodies into Michelangelesque forms. A new Yale study suggests that for some individuals this intense physical exertion could be deadly. Since reporting in 2003 on a disquieting link between weight lifting and tearing of the aorta in five individuals, John A. Elefteriades, M.D., professor of surgery, and colleagues have identified 31 individuals who experienced an internal aortic tearing, or “dissection,” following heavy lifting. Most were younger than age 50, in good health, and had no prior history of cardiac disease. A third of these individuals died. In the July issue of Cardiology, the team notes that nearly all of the individuals who experienced tearing had unknowingly been living with an abnormally enlarged aorta, a condition that occurs in hundreds of thousands of American men. The authors suggest that a spike in blood pressure caused by heavy lifting may rip the arterial wall in individuals with an undiagnosed enlargement, and they urge those planning to pump serious iron to be screened for aortic enlargement. . How cold sore viruses play hide-and-seekCold sores, which are caused by the herpes simplex virus (HSV), usually heal fairly quickly. But because HSV cleverly conceals itself in an inactive form, the body’s immune system never completely eradicates it, and the painful sores tend to flare up again and again. In the August issue of Nature Immunology, a team led by Peter Cresswell, Ph.D., Howard Hughes Medical Institute investigator and professor in the Section of Immunobiology, provide new insights into HSV’s vanishing act. The immune system uses proteins known as CD1d molecules to detect HSV. Infection modifies these molecules, which move in a continuous loop from the interior of the cell to the cell surface, where the modified forms are “displayed” to immune cells. But Cresswell’s group found that HSV causes CD1d molecules to accumulate inside the cell, preventing them from reaching the cell surface. As a result, the virus can remain hidden until its next opportunity to wreak cold sore havoc. Further studies of how HSV foils CD1d may suggest therapeutic strategies to eliminate cold sores for good. Nicotine’s addictive grip on the brain
Smokers find it enormously difficult to quit: of those who try, only about 10 percent successfully kick the habit each year. The stubbornness of tobacco addiction has been attributed to nicotine, which activates numerous neural networks in the brain by locking onto proteins known as nicotinic acetylcholine receptors, or nAChRs. Using neuroimaging technology, Julie K. Staley, Ph.D., associate professor of psychiatry and diagnostic radiology, and colleagues compared the number of nAChRs in nonsmokers and in smokers who had abstained from cigarettes for about seven days. As reported in the August 23 issue of The Journal of Neuroscience, the team observed significantly higher densities of nAChRs in the brains of the abstaining smokers than in nonsmokers. Moreover, the smokers’ urge to light up to relieve withdrawal symptoms was closely related to the number of nAChRs seen in certain brain regions. “This paves the way for determining why some smokers, such as women and those with neuropsychiatric disorders, have more difficulty quitting,” Staley says. An early start on the road to reasonThe cerebral cortex, a layer of cells just a few millimeters thick on the outermost surface of the brain, is largely what makes humans “noble in reason and infinite in faculties.” New Yale research shows that developing embryos generate the first neurons of the cortex only 31 days after fertilization—much earlier than previously thought. Using precise cellular markers, Pasko Rakic, M.D., Ph.D., chair and Dorys McConnell Duberg Professor of Neurobiology, and colleagues at the University of Oxford discovered “predecessor” neurons in human embryos before the neural tube, the precursor of the central nervous system, had completely closed. These precocious cells produce long extensions that may pull them to different locations as the brain develops while also acting as temporary scaffolds to guide late-blooming cortical neurons to their proper locations. In the July issue of Nature Neuroscience, the researchers say that studying how predecessor cells help to generate and wire up the 20 billion neurons of the adult human cortex may give us new insights into how we differ from our primate ancestors and shed light on the causes of mental illness. 
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