1. Department of Internal Medicine, Naval Medical Center San Diego , San Diego, CA 92134, USA
2. Department of Gastroenterology, Naval Medical Center San Diego , San Diego, CA 92134, USA
3. Division of Gastroenterology, Naval Medical Center Camp Lejeune , Camp Lejeune, NC 28547, USA
4. Department of Pathology, Naval Medical Center San Diego , San Diego, CA 92134, USA