1. Division of Gastroenterology, Department of Internal Medicine, William Beaumont Hospital at Royal Oak, 3535 W. Thirteen Mile Rd, Royal Oak, MI 48073, USA
2. Department of Pathology, William Beaumont Hospital at Royal Oak, 3600 W. Thirteen Mile Rd, Royal Oak, MI 48073, USA
3. Department of Pathology, Oakland University William Beaumont School of Medicine, 3600 W. Thirteen Mile Rd, Royal Oak, MI 48073, USA
4. Division of Gastroenterology, Department of Medicine, Building 1, Room 3210, Aleda E. Lutz VA Medical Center, 1500 Weiss St, Saginaw, MI 48602, USA