Inside this issueCover storiesSmoothing the roadIt's only rock 'n' roll, but it supports cancer researchCartoonist's work on wartime trauma garners awardPartnershipsAfter heartbreak, a commitment to make a differenceGrants & contractsPeopleLifelines: David J. LeffellYale geneticist wins Wiley PrizeExpert on myeloma to head hematologyOut & aboutScienceA scientific assault on brain diseasesAdvances: A two-pronged tactic to grow new bone | Sloppy gene repairs: a cause of lymphoma?HealthA 'reluctant honoree' receives his due at lastAdvances: Taking a bite out of stroke | Age no barrier for heart bypass surgeryEducationA match made in medical school  
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AdvancesHealth and science news from YaleA two-pronged tactic to grow new bone
School of Medicine researchers have devised a novel technique—removing bone marrow and injecting a hormone—that promotes rapid formation of new bone. “This could radically change the way patients are currently treated for weakened or fractured hips, vertebrae and acute traumatic long-bone fractures,” says senior author Agnès M. Vignery, D.D.S., Ph.D., associate professor of orthopaedics and rehabilitation. Existing therapy, which involves surgery and artificial materials, often leads to unsatisfactory outcomes. As reported in the February issue of Tissue Engineering: Part A, Vignery’s team removed marrow from thigh bones in rats and then gave them daily injections of parathyroid hormone (PTH), which stimulates bone growth (see right panel of photo). The procedure created new bone tissue that appeared structurally and biologically normal, and endowed the bone with improved biomechanical properties at a rate that can’t be achieved by injecting hormones alone, Vignery says. New research will determine whether the newly formed bone can be preserved and whether the technique is effective in other animals. Sloppy gene repairs: a cause of lymphoma?The blood and lymphatic systems transport the immune system’s infection-fighting B cells throughout the body. During an immune response, random mutations are introduced in B cell genes by a process known as somatic hypermutation (SHM), which makes the cells more effective at fighting a variety of foreign invaders. To keep harmful mutations at bay, B cells contain DNA repair enzymes that repair faulty genes created by SHM, but little is known about how effective these repair mechanisms are, or whether they might be related to the development of the cancerous B cells seen in lymphoma. In the February 14 issue of Nature, a team led by David G. Schatz, Ph.D., professor of immunobiology and Howard Hughes Medical Institute investigator, found that almost 25 percent of B cell genes accumulated mutations, including genes that are strongly associated with human lymphomas. “The implications of these findings are considerable,” Schatz says. “It now seems likely that anything that compromises the function of these DNA repair processes could lead to widespread mutations and an increased risk of cancer.”. Taking a bite out of stroke
It may seem hard to believe that the rather menacing creature above, the Malayan pit viper, could be good for your health, but a Phase III research study of a compound found in the snake’s venom could provide new hope for stroke victims. Doctors at Yale-New Haven Hospital (YNHH) are administering ancrod (trade name Viprinex), a drug derived from pit viper venom, to eligible patients who enter the hospital with symptoms of acute ischemic stroke. In such cases doctors typically administer a clot-breaking agent known as tissue plasminogen activator, or tPA, but it must be given no more than three hours after stroke symptoms appear to be effective. Ancrod, which has a potent anticoagulant effect, may be effective up to six hours after symptoms begin. “If ancrod is proven safe and effective,” says Joseph Schindler, M.D., clinical director of the YNHH Stroke Center, “it will double the time frame during which stroke patients can be treated.” YNHH is the only Connecticut hospital participating in the trial, which is expected to last for one to two years. Age no barrier for heart bypass surgeryOver the last 40 years, coronary artery bypass graft (CABG, pronounced “cabbage”) surgery has become commonplace; the National Center for Health Statistics estimates that 469,000 bypass procedures were performed on 261,000 patients in 2005. According to a Yale study published in the December issue of The American Journal of Cardiology, even individuals in their 90s with heart disease may benefit from CABG surgery. A research team led by Judith H. Lichtman, Ph.D., M.P.H., associate professor of epidemiology at Yale School of Public Health, studied outcomes of the procedure in 4,224 Medicare patients in their 90s who underwent the surgery from 1993 through 1999. The group found that age did not significantly lessen the procedure’s success. Lichtman and senior author Harlan M. Krumholz, the Harold H. Hines, Jr. Professor of Medicine, note that women, while more likely to be discharged to nursing homes after the surgery, had better post-surgical survival rates than men. They also caution that additional research is needed to fully assess the suitability of CABG surgery for this elderly population.
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