1 Department of Gastroenterology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
2 Department of Gastroenterology, Scott & White Healthcare, Killeen, Texas, USA and Texas A&M Health Science Center College of Medicine, Bryan, Texas, USA.
3 Skeletal Clinical Studies Unit, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA.