1. Health Sciences Center (P.S.P.), St. John's, Newfoundland, Canada A1B 3V6
2. Stanford University School of Medicine (G.M.C.), Palo Alto, California 94304
3. Denver Nephrology (G.A.B.), Denver, Colorado 20230
4. Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (R.C.-R.), Mexico City, Mexico D.F. 140100
5. Inserm Unit 1088, UFR Médecine/Pharmacie (T.B.D.), Université de Picardie, 80037 Amiens, France
6. Universitätsklinikum der RWTH Aachen (J.F.), 52074 Aachen, Germany
7. University of Minnesota (C.A.H.), Minneapolis, Minnesota 55415
8. Hôpital Manhès (G.M.L.), Paris, France 91712
9. Duke Clinical Research Institute (K.W.M.), Duke University Medical Center, Durham, North Carolina 27705
10. Indiana University School of Medicine and Roudebush Veterans Administration Medical Center (S.M.M.), Indianapolis, Indiana 46202
11. University College London (D.C.W.), London, United Kingdom NW32PF
12. Amgen, Inc (B.D., M.-L.T., D.M.M., W.G.G.), Thousand Oaks, California 91320