Stephen Z. Fadem, M.D, F.A.C.P., FASN Clinical Professor Baylor College of MedicineDepartment of Medicine Division of NephrologyHoustonTexas USAThomas A. Golper, M.D., F.A.C.P., F.A.S.N.Emeritus Professor of MedicineVanderbilt University Medical CenterNashvilleTN USAProfessor of MedicineThe Robert Larner College of Medicine at the University of VermontBurlingtonVermontUSAJosé A. Moura-Neto, MD, FASN, FRCP Professor of Internal MedicineBahiana School of Medicine and Public HealthSalvador BahiaBrazil