Our main office is located at: 6535 N. Charles Street, Suite 400, Baltimore, MD  21204  Phone:  410-828-7417            Fax:  410-828-4695 Board Certified Endocrinologists: James H. Mersey, M.D. Dr. Mersey went to Johns Hopkins Medical School, and spent 3 years in a medical residency at Johns Hopkins.  He completed a fellowship in Endocrinology at Peter Bent Brigham Hospital in Boston.  He then spent 11 years on the full-time faculty at the University of Maryland.  He is now in private practice and the chief of Endocrinology at Greater Baltimore Medical Center.  In addition he retains faculty appointments at University of Maryland and Johns Hopkins.  Dr. Mersey is a fellow of the American College of Physicians and the American College of Endocrinology.  Dr. Mersey and his associates are actively involved in clinical research in diabetes, hypertension, lipid disorders and osteoporosis.  He also teaches house staff and fellows and directs the Geckle Diabetes Center at GBMC.  Joanna B. Tyzack, M.D. Dr. Tyzack went to the medical University of South Carolina, then completed her residency in internal medicine, and her fellowship in Endocrinology.  She then joined James H. Mersey, MDPA.  She is interested in all aspects of Endocrinology.       Ruth S. Horowitz, M.D. Dr. Horowitz received her undergraduate degree from Oberlin College and her medical degree from the University of Cincinnati College of Medicine.  She went on to complete both her residency in Internal Medicine and fellowship in Endocrinology and Metabolism at the University of Maryland College of Medicine.  She then spent five years on the faculty of Sinai Hospital of Baltimore, and was a part time Instructor of Medicine at Johns Hopkins School of Medicine.  She joined Bay Endocrinology in 1999.  She is board certified in both, Internal Medicine and Diabetes, Endocrinology and Metabolism. She is a member of the Endocrine Society, American Association of Clinical Endocrinologist and the American College of Physicians.   Her interests include diabetes, thyroid disorders, osteoporosis, and lipid disorders.  Francis Y.G. Lee, Sr., M.D. Dr. Lee attended Yale University, where he received his bachelors degree. He attended medical school at Columbia University College of Physicians and Surgeons. He did a general surgery internship and part of a neurosurgery residency at Temple University Hospital, before completing his medical residency at Sinai Hospital of Baltimore. Dr. Lee then went on to do a Fellowship in Endocrinology at the Johns Hopkins University School of Medicine. After the fellowship, he practiced Clinical Endocrinology in Bloomington, Indiana for four years, during which time he was also a Clinical Assistant Professor at the Indiana University School of Medicine. Dr. Lee is board certified in Internal Medicine and Diabetes, Endocrinology and Metabolism. He has been a principal investigator in clinical diabetes research. He has lectured extensively throughout the nation on topics including diabetes, lipid disorders, obesity, osteoporosis, women’s health and thyroid disorders. Dr. Lee is interested in all aspects of endocrinology. Philip Levin, M.D. Dr. Levin is board certified in Endocrinology and Internal Medicine, and a graduate of the University of Maryland School of Medicine. He received internship and residency training at Yale Medical Center Hospitals and Georgetown University Hospital. His fellowship training was at Ohio State University Hospital and NIH. Dr. Levin is a Clinical Associate Professor at the University of Maryland School of Medicine. He has a longstanding involvement in diabetes and directs a diabetes treatment center. Dr. Levin has also been active in diabetes clinical research and has been an NIH Principal Investigator for the DCCT diabetes trial. He has been a principal investigator for studies in inhaled insulins, new oral agents and glucose sensors, and has more than 30 publications. Ann E. Fraker, M.D. Dr. Fraker received her undergraduate degree from Princeton University and her medical degree from the University of Pittsburgh School of Medicine.  She completed residency in Internal Medicine at the University of Pittsburgh Medical Center and fellowship in Endocrinology and Metabolism at UMass Medical Center.  Dr. Fraker is board certified in Internal Medicine and Endocrinology, Diabetes and Metabolism.  Her interests include general endocrinology, pituitary disease and thyroid disease. Craig G. Haber, M.D. Dr. Haber trained in Internal Medicine at Maimonides Medical Center in Brooklyn, New York. After a brief stint as Director of Emergency Medical Services in the same institution, he went on to do two fellowships in Endocrinology. He studied Metabolism for two years at Johns Hopkins Medical School. He then went on to do clinical research at the University of Maryland Medical School. Upon finishing his training, he was appointed Assistant Professor of Medicine in Endocrinology. He left this position after four years to pursue a more “hands on” clinical career in the private practice of Medicine and Endocrinology in Reisterstown, MD, where he has been ever since. He joined the practice of James Mersey, MD, with an avid interest in Diabetes management and Disorders of Lipid Metabolism and Obesity. Corina C. Fratila, M.D. Dr Fratila attended Carol Davila University of Medicine and Pharmacy in Romania and then completed the medical residency and Endocrinology fellowship at Albert Einstein College of Medicine/ Jacobi Hospital / Montefiore Medical Center in Bronx, New York. Dr Fratila is board certified in Internal Medicine and Diabetes, Endocrinology and Metabolism. Her areas of interest include diabetes, obesity, women’s health and thyroid disease. Meena A. Khan, M.D. Dr. Khan received her bachelors degree from University of Virginia and her medical degree from the University of Maryland.  She then completed a residency in Internal Medicine at the University of Chicago and an Endocrinology fellowship at the University of Maryland.  She was elected to the Alpha Omega Alpha honor society by the University of Maryland medical school.  She is interested in all aspects of endocrinology, particularly thyroid disease, diabetes, and osteoporosis.