1. Medical Service, VA Medical Center, and Department of Medicine, University of Minnesota, Minneapolis, Minnesota1;
2. Medical Service, VA Medical Center, and Department of Medicine and Center for Microbial Pathogenesis, State University of New York at Buffalo, Buffalo, New York2; and
3. Division of Gastroenterology, Children's Hospital and Regional Medical Center, and Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington3