1. Department of Legal Medicine, Graduate School of Medicine, Chiba University, Chuo, Chiba 260-8670, Japan
2. Laboratory of Forensic Toxicology, Graduate School of Pharmaceutical Sciences, Chiba University, Chuo, Chiba 260-8675, Japan
3. Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
4. Laboratory of Toxicology and Environmental Health, Graduate School of Pharmaceutical Sciences, Chiba University, Chuo, Chiba 260-8675, Japan