1. Department of Epizootiology, Faculty of Veterinary Medicine; Hokkaido University; Sapporo Hokkaido 060
2. Laboratory of Cell Biology, Basic Research Laboratories; Toray Industries, Inc.; Kamakura Kanagawa 248
3. Laboratory of Molecular Oncology; The Institute of Physical and Chemical Research; Wako Saitama 351-01
4. Department of Veterinary Microbiology, School of Veterinary Medicine and Animal Science; Kitasato University; Towada Aomori 034
5. Department of Veterinary Microbiology; College of Dairy Agriculture; Ebetsu Hokkaido 069