1. Department of Endocrinology and Metabolism, Tokyo Metropolitan Tama Medical Center, Japan
2. Department of Diabetes and Endocrinology, University of Yamanashi Hospital, Japan
3. Department of Gastrointestinal and General Surgery, Tokyo Metropolitan Tama Medical Center, Japan
4. Department of Pathology, Tokyo Metropolitan Tama Medical Center, Japan
5. Department of Pathology, Jichi Medical University, Japan
6. Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan