The OU College of Medicine has named three new department chairs: William Sonntag, Ph.D., chair of the Department of Biochemistry and Microbiology; Leonidas Tsiokas, Ph.D., chair of the Department of Cell Biology; and James Barrett, M.D., interim chair of the Department of Family and Preventive Medicine.

Prior to being named chair, Sonntag served as interim chair of the Department of Biochemistry and Microbiology since 2018. 

In 2007, he arrived in Oklahoma to serve as the founding director of the Reynolds Oklahoma Center on Aging in the OU College of Medicine’s Department of Geriatric Medicine. He held the position of Professor and Donald W. Reynolds Chair of Aging Research. He is also director of the Center for Geroscience and Healthy Brain Aging.

Sonntag began his faculty career at the Wake Forest University School of Medicine in Winston-Salem, North Carolina, where he served for 23 years in the Department of Physiology and Pharmacology. While there, he held the position of Scientific Director of Basic Science Research in the Roena Kulynych Center for Memory and Cognition Research of the J. Paul Sticht Center on Aging.

Sonntag’s specific research interest is the interaction between the endocrine, vascular and the central nervous system that leads to mild cognitive impairment, specifically vascular cognitive impairment. He is principal investigator for the Cellular and Molecular Geroscience CoBRE grant at the OU Health Sciences Center, and he leads the Development Core of the Oklahoma Nathan Shock Center of Excellence in the Biology of Aging.

Tsiokas brings a long background in cell biology to his new leadership role. He has served as Vice Chair of Research in the Department of Cell Biology and Adjunct Professor in the Department of Medicine. He holds the John S. Gammil Endowed Chair in Polycystic Kidney Disease and is a George Lynn Cross Research Professor.

His research team has made important contributions to the understanding of the pathophysiology of diseases, including: the autosomal dominant form of Polycystic Kidney Disease, familial hypocalciuric hypercalcemia, and Stormorken syndrome. His research has been published in high-impact journals and his laboratory has been funded by the National Institutes of Health for 17 consecutive years. 

Tsiokas has taught students from the Graduate College, College of Medicine and College of Dentistry, and he serves as an advisor and mentor for graduate students. He is a member of the American Society of Nephrology, the American Society for Cell Biology, and the American Association for the Advancement of Science. 

Before being named interim chair of the Department of Family and Preventive Medicine, Barrett served as vice chair of the department since 2013.

Barrett joined the faculty in 1991 and has served in several capacities, including director of the Primary Care Sports Medicine Program from 1991 to 2005 and director of the Family Medicine Residency Program from 2005 to 2018. He is a professor in the department and holds the Edith Kinney Gaylord Presidential Professorship. He has been extensively involved in curriculum development for the department, and he has mentored numerous students, residents and fellows.

His dedication to sports medicine and family medicine extends beyond the campus. He is the team physician for the Oklahoma City Thunder NBA team. Barrett was named NBA Physician of the Year for the 2019-2020 NBA season by the National Basketball Athletic Trainer’s Association.