1. Department of Endocrinology, Metabolism and Nephrology , Kochi Medical School, Kochi University , Kohasu, Oko-cho, Nankoku, Kochi 783-8505 , Japan
2. Department of Pediatrics, Kochi Medical School , Kochi University , Kohasu, Oko-cho, Nankoku, Kochi 783-8505 , Japan
3. Department of Hematology and Respiratory Medicine , Kochi Medical School, Kochi; University, Kohasu , Oko-cho, Nankoku, Kochi 783-8505 , Japan
4. Department of Otolaryngology , Kochi Medical School, Kochi University , Kohasu, Oko-cho, Nankoku, Kochi 783-8505 , Japan
5. Laboratory of Anatomy , Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine , Hokkaido University , Kita 18, Nishi 9, Kita-Ku, Sapporo 060-0818 , Japan