1. From the Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand; the Slone Epidemiology Center, Boston University, MA; the Department of Medicine, Faculty of Medicine, Khonkaen University, Khonkaen, Thailand; the University of South Florida, Tampa, FL; and the Hematology Branch, National Heart, Lung, and Blood Institute, Bethesda, MD.