1. Cell Technology Center, Roman Industries Co. Ltd., Yokohama 236-0004, Japan
2. Department of Innovative Surgery, National Research Institute for Child Health and Development, Tokyo 157-8535, Japan
3. Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
4. Departments of Clinical Pharmacology and Pharmacology, Jichi Medical School, Yakushiji, Tochigi 329-0431, Japan