[1] UNIV PITTSBURGH,SCH MED,DEPT SURG,FALK CLIN,3601 5TH AVE,PITTSBURGH,PA 15213
[2] BAYLOR UNIV,MED CTR,DEPT SURG,DALLAS,TX
[3] UNIV PITTSBURGH,SCH MED,DIV GASTROENTEROL,PITTSBURGH,PA 15213
[4] UNIV PITTSBURGH,SCH MED,DEPT INTERNAL MED,PITTSBURGH,PA 15213
[5] MAYO CLIN & MAYO FDN,DIV GASTROENTEROL & INTERNAL MED,ROCHESTER,MN 55905
[6] MAYO CLIN & MAYO FDN,BIOSTAT SECT,ROCHESTER,MN 55905
[7] UNIV WASHINGTON,DEPT BIOSTAT,SEATTLE,WA 98195