1. From the Departments of Medicine and Clinical Biochemistry, St. Michael’s Hospital and University of Toronto, Ontario (R.A.H., P.W.C.), the Department of Biochemistry, Dalhousie University, Halifax, Nova Scotia (W.C.B.); the School of Nursing, University of Victoria, British Columbia (J.H.B.); and the Department of Biochemistry, University of Toronto, Ontario, Canada (P.W.C.).