1. Department of Parasitology, Kyungpook National University School of Medicine, Daegu 700-422, Korea.
2. Department of Parasitology and Malariology, PICR, College of Medicine and Frontier Inje Research for Science and Technology, Inje University, Busan 614-735, Korea.
3. Department of Biological Science, Seoul National University, Seoul 151-742, Korea.