Dean David A. Kessler, M.D., has announced the appointments of four new departmental and section leaders.Charles J. Lockwood, M.D., FW ’89, a specialist in high-risk obstetrics, became professor and chair of the Department of Obstetrics and Gynecology on July 1. Lockwood came to Yale from New York University, where he was the Stanley H. Kaplan Professor of Obstetrics and Gynecology and chair of the department since 1995. Lockwood is a 1981 medical graduate of the University of Pennsylvania who trained as a resident at Pennsylvania Hospital before coming to Yale as a fellow in maternal-fetal medicine in 1985. He succeeds interim chair Peter E. Schwartz, M.D., HS ’70, who heads the section of gynecologic oncology, and Frederick Naftolin, M.D., Ph.D., who stepped down as chair in 2000.Cancer researcher and clinician Peter M. Glazer, M.D. ’87, Ph.D. ’87, became chair of the Department of Therapeutic Radiology on August 12, succeeding James J. Fischer, M.D., who had led the department since 1972. Glazer did his residency at Yale and joined the faculty in 1991. His research focuses on the cellular processes of DNA repair and mutagenesis and the phenomenon of radioresistance. Glazer, who has a secondary appointment in the Department of Genetics, is also interested in gene targeting and gene therapy strategies for cancer, viral infections and genetic diseases. He pioneered methods for in vivo measurements of mutagenesis and applied these to experiments demonstrating fundamental pathways of genetic instability in cancer. Glazer is co-director of the molecular oncology program in the Yale Cancer Center and a member of the Cancer Center executive committee. Margaret K. Hostetter, M.D., became chair of the Department of Pediatrics on September 1. Hostetter came to Yale four years ago from the University of Minnesota, where she co-founded the nation’s first international adoption clinic in 1986. She was recruited to Yale to head the section of pediatric immunology and serve as director of the Yale Child Health Research Center. She was elected to the Institute of Medicine in 2001.An alumna of Baylor College of Medicine, Hostetter did her postgraduate training at Children’s Hospital in Boston and taught at Harvard before joining the Minnesota faculty in 1982. Her research on the molecular pathogenesis of pneumococcal and candida infections has received NIH funding for two decades. She is also the principal investigator of the Pediatric Scientist Development Program, a $13 million initiative of the National Institute of Child Health and Human Development.She succeeds Norman J. Siegel, M.D., HS ’70, who served as the interim chair since 2000 when his predecessor, Joseph B. Warshaw, M.D., left Yale to become dean of the University of Vermont College of Medicine.John Harley Warner, Ph.D., became chair of the Section of the History of Medicine on July 1, succeeding Frederic L. Holmes, Ph.D., who stepped down after 23 years. Warner has also been appointed by the university provost to the newly created position of chair of the Program in the History of Medicine and Science.Warner received his doctoral degree in the history of science from Harvard in 1984 and spent two years as a postdoctoral fellow in London at the Wellcome Institute for the History of Medicine. He joined the Yale faculty in 1986. His research includes wide-ranging explorations of medical institutions, practitioners, ideas and practices, especially in the United States and the United Kingdom.Since becoming dean in 1997, Kessler has appointed new chairs in 11 departments and free-standing academic sections, including Cell Biology, Genetics, Pharmacology, Molecular and Cellular Physiology, Surgery, the Child Study Center and Microbial Pathogenesis. Searches are under way for successors to M. Bruce Shields, M.D., who has announced his intention to step down as chair of Ophthalmology and Visual Science; Albert B. Deisseroth, M.D., Ph.D., the former chief of the section of medical oncology who became president and CEO of the Sidney Kimmel Cancer Center in San Diego last year; and Yale Cancer Center Director Vincent T. DeVita Jr., M.D., HS ’66, who is planning to step down at the end of this academic year.