1. Veterinary Medical Center, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku, Ourai Kita, Izumisano, Osaka 598-8531, Japan
2. Laboratory of Cell Pathobiology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku, Ourai Kita, Izumisano, Osaka 598-8531, Japan
3. Laboratory of Veterinary Internal Medicine, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku, Ourai Kita, Izumisano, Osaka 598-8531, Japan