1. Department of Endocrinology and Metabolism, KKR Suifu Hospital, Mito 311-4141, Japan
2. Department of Surgery, KKR Suifu Hospital, Mito 311-4141, Japan
3. Department of Infection Control and Clinical Laboratory Medicine, Dokkyo Medical University, Tochigi 321-0293, Japan
4. Department of Endocrinology and Applied Medical Science, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan