1. National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2–13, Inada-cho Obihiro, Hokkaido, Japan 080–8555.
2. Department of Parasitology, University of the Philippines, Manila, Philippines.
3. Laboratory of Molecular Immunology, University of Tokyo, Tokyo, Japan.
4. Laboratory of Tropical Medicine and Parasitology, Dokkyo Medical University, Tochigi, Japan.