1. Department of Biochemistry, College of Natural Science, Chungbuk National University, Cheongju, Chungbuk 361-763, Korea.
2. Bacteriology and Parasitology Division, National Veterinary Research and Quarantine Service, Anyang 430-824, Korea.
3. Institute of BioMedicals, Bioland Ltd., Ochang, Chungbuk 363-883, Korea.
4. Department of Medical Environmental Biology, College of Medicine, Chung-Ang University, Seoul 156-756, Korea.
5. Department of Parasitology and Catholic Institute of Parasitic Diseases, College of Medicine, Catholic University of Korea, Seoul 137-701, Korea.