1. Department of Parasitology and Immunology; University of Tokushima School of Medicine; Tokushima Tokushima 770 Japan
2. Second Department of Pathology; University of Tokushima School of Medicine; Tokushima Tokushima 770 Japan
3. Institute for Animal Experimentation; University of Tokushima School of Medicine; Tokushima Tokushima 770 Japan