Carla Saenz1, John F Tisdale2. 1. Regional Program on Bioethics, Knowledge Management, Bioethics and Research, Pan American Health Organization, Washington, DC. 2. National Heart, Lung, and Blood Institute/National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland. Electronic address: johntis@mail.nih.gov.