[1] DUKE UNIV, MED CTR, DURHAM, NC 27710 USA
[2] GEISINGER MED CTR, DANVILLE, PA 17822 USA
[3] UNIV LOUISVILLE, DES MOINES, IA USA
[4] MERCY HOSP, DES MOINES, IA USA
[5] ROCHESTER GEN HOSP, ROCHESTER, NY 14621 USA
[6] ST FRANCIS HOSP & MED CTR, BEECH GROVE, IN USA
[7] ST PATRICKS HOSP, MISSOULA, MT USA
[8] CLEVELAND CLIN, CLEVELAND, OH 44106 USA
[9] POLIKLIN TECH UNIV MUNICH, MUNICH, GERMANY