| Project/Area Number |
10670524
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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 | Hiroshima University (2000)
Okinaka Memorial Institute for Medical Research (1998-1999) |
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Principal Investigator |
CHAYAMA Kazuaki Hiroshima University, Faculty of Medicine, Professor., 医学部, 教授 (00211376)
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| Co-Investigator(Kenkyū-buntansha) |
KUMADA Hiromitsu Research Institute for geriatric diseases, Okinaka, 研究員 (20124307)
池田 健次 財団法人 冲中記念成人病研究所, 研究員 (80211027)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1998: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | lamivudine / PCR-RFLP / mutation / resistance / PCR / YMDD / 長期投与 / B型肝炎ウイルス / 点突然変異 / C型肝炎ウイルス / ラミブジン / YMDDモチーフ / YVDD / YIDD |
|---|
| Research Abstract |
Treatment of hepatitis B virus with lamivudine is effective in suppressing virus replication and results in reduced inflammatory activity. However, the emergence of lamivudine-resistant mutant virus, with amino acid substitution in the YMDD motif of DNA polymerase, has been reported. Using a sensitive and specific polymerase chain reaction-based method developed in this study, the emergence of YMDD mutants was detected 1 to 4 months before DNA breakthrough but not detected in any of pretreatment sera. We also detected the emergence and takeover of YMDD mutant and re-takeover by wild type during and after long-term lamivudine therapy. Cumulative appearance of YMDD mutants increased by time, but became plateau three years from the beginning of the therapy. The final appearance rate of YMDD mutants was 47.6%. Our results suggest that the replication of YMDD mutant viruses is less than wild type and is re-overtaken by wild type after cessation of therapy. Re administration of lamivudine, possibly combined with other anti viral therapy, might be useful in some patients experiencing hepatitis with lamivudine resistant variants.
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