1. Department of Internal Medicine, East Tennessee State University, Quillen College of Medicine, P.O. Box 70622, Johnson City, TN 37614, USA
2. Department of Gastroenterology, East Tennessee State University, Quillen College of Medicine, Johnson City, TN 37614, USA
3. Department of Oncology, VA Medical Center, Quillen College of Medicine, Mountain Home, TN 37684, USA