1. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Edward Doisy Research Center, Saint Louis University School of Medicine, 1100 S. Grand Boulevard, Room 205, St. Louis, MO 63104, USA
2. Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45237, USA
3. Department of Internal Medicine and Public Medicine, Clinica Medica “A. Murri”, University of Bari Medical School, 70124 Bari, Italy