1. Department of Parasitology and Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 660-751, Korea.
2. Department of Medical Laboratory Sciences, College of Health Sciences, Yonsei University, Wonju 220-710, Korea.
3. Hydra Enterprises Ltd., P.O. 2184, Vancouver, BC V6B 3V7, Canada.
4. Department of Parasitology and Tropical Medicine, Seoul National University College of Medicine, and Institute of Endemic Diseases, Seoul National University Medical Research Center, Seoul 110-799, Korea.