1. Departments of Medicine and Physiology (H.D., A.C.S., C.X., A.G., L.S., G.F.L.), Division of Endocrinology and Metabolism, University of Toronto, Toronto, Ontario, Canada M5G 2C4
2. Department of Medicine (D.J.D.), Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, Toronto, Ontario, Canada M5G 1X5