1. Oregon Health & Science University (E.S.O., C.M.N.), Portland, Oregon 97239;
2. Le Centre hospitalier de l’Université Laval (F.L.), Québec City, Canada G1K 7P4;
3. University of California, San Diego (E.B.-C.), La Jolla, California 92161;
4. University of Pittsburgh (J.A.C., A.L.P., J.Z.), Pittsburgh, Pennsylvania 15260;
5. San Francisco Coordinating Center (S.R.C.), San Francisco, California 94107;
6. University of Minnesota (K.E.), Minneapolis, Minnesota 55455;
7. Lund University (M.K.), 221 00 Malmö, Sweden;
8. The Chinese University of Hong Kong (E.L., P.C.L.), Hong Kong 1, China;
9. University of Uppsala (O.L.), 753 12 Uppsala, Sweden;
10. University of Gothenburg (D.M., L.V., C.O.), 411 24 Göteborg, Sweden;
11. Stanford University (M.L.S.), Palo Alto, California 94305;
12. University of Tokyo (K.N., N.Y.), Tokyo 113-8655, Japan