1. Department of Pediatrics, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke 329-0498, Japan
2. Department of Infectious Disease, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke 329-0498, Japan
3. Department of Emergency Center, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke 329-0498, Japan
4. Department of Intensive Care Unit, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke 329-0498, Japan
5. Research & Development Division, Sekisui Medical Co., Ltd., Chuo-ku, Tokyo 103-0027, Japan