| Project/Area Number |
08670562
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Gastroenterology
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| Research Institution | University of Tokyo |
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Principal Investigator |
YOSHIDA Haruhiko University of Tokyo, Faculty of Medicin, Instructer, 医学部・附属病院, 助手 (60240305)
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| Co-Investigator(Kenkyū-buntansha) |
KANAI Fumihiko University of Tokyo, Faculty of Medicin, Medicine, 医学部・附属病院, 医員
KATO Naoya University of Tokyo, Faculty of Medicin, Medicine, 医学部・附属病院, 医員
SHIRATORI Yasushi University of Tokyo, Faculty of Medicin, Lecturer, 医学部・附属病院, 講師 (70196624)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1997: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1996: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Helicobacter pylori / Vacuolating cytotoxin / recombinant VacA / Virulence factor / VacA / vacuolation / sequencing / antibody |
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| Research Abstract |
Clinical features of Helicobacter pylori infection vary widely among patients. Production of the cytotoxin VacA has been alleged to be responsible for virulence by several reports from Western countries. This research sought to confirm the VacA-related virulence in Japan.
This research has revealed, however, that most H.pylori isolates in Japan are positive for VacA irrespective of gastroduodenal status in the hosts. The cytotoxin activity in the supernatant of bacterial culture was usually positive, and the nucleotide sequence analysis of vacA gene revealed cytotoxinsecreting genotype. By using recombinant VacA expressed in E.coli, we further confirmed the production of VacA by bacterial isolates and the seropositivity of anti-VacA antibody in Japanese patients.
It was concluded that VacA is not the major virulence determinant factor in Japan. However, the high prevalence of VacA-positive strains may be related to the high incidence of gastric cancer in Japan.
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