1. Department of Basic Veterinary ScienceThe United Graduate School of Veterinary Science, Yamaguchi UniversityYamaguchi753‐8515Japan
2. Tsukuba Safety AssessmentBanyu Pharmaceutical Co., Ltd.Ibaraki300‐2611Japan
3. Department of Veterinary Anatomy, Faculty of AgricultureTottori UniversityTottori680‐8553Japan