1. Department of MicrobiologyYokohama City University School of MedicineKanagawa 236‐0004Japan
2. Isehara Research LaboratoryTechnology and Development DivisionKanto Chemical Co., Inc., Kanagawa 259‐1146Japan
3. Division of VirologyKawasaki city institute for public healthKanagawa 210‐0821Japan
4. School of Medical TechnologyFaculty of Health SciencesGunma Paz UniversityGunma 370‐0006Japan
5. Department of Dermatology and PathologyUniversity of PittsburghPAUSA
6. Cancer Virology ProgramUniversity of Pittsburgh Medical Center Hillman Cancer CenterPittsburghPAUnited States