1. From the Departments of Medicine and Therapeutics (A.Y.-M.W., M.W., S.-F.L., J.E.S.) and Chemical Pathology (C.W.-K.L., I.H.-S.C.), Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong; current address (C.W.-K.L.): Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Taipa, Macau; current address (A.Y.-M.W., M.W.): Department of Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong.