1. Department of Internal Medicine; Texas Tech University Health Sciences Center/Paul L. Foster School of Medicine; El Paso TX USA
2. Division of Gastroenterology; Department of Internal Medicine; Texas Tech University Health Sciences Center/Paul L. Foster School of Medicine; El Paso TX USA
3. Division of Gastroenterology; University of Pennsylvania Perelman School of Medicine; Philadelphia PA USA
4. Department of Surgery; Texas Tech University Health Sciences Center/Paul L. Foster School of Medicine; El Paso TX USA
5. Department of Pathology; Texas Tech University Health Sciences Center/Paul L. Foster School of Medicine; El Paso TX USA