1997 Fiscal Year Final Research Report Summary
Development of a diagnostic kit for serum marker-negative viral hepatitis B
| Project/Area Number |
07557023
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Human pathology
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| Research Institution | Nihon University School of Medicine |
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Principal Investigator |
UCHIDA Toshikazu Nihon Univ.School of Mex.Asso.P, 医学部, 助教授 (80060078)
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| Co-Investigator(Kenkyū-buntansha) |
MAEDA Toshiro Mitsubishi Chem.Dx.sey sue-chief, 診断システム, 副主任研究員
ARAKAWA Yasuyuki Nihon Univ.School of Prof., 医学部, 教授 (50059698)
SUGITANI Masahiko Nihon Univ.School of Assi.Prof., 医学部, 講師 (40187654)
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| Project Period (FY) |
1995 – 1997
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| Keywords | hepatitis B / viral hepatitis / HBs antigen / envelope / X gene / X protein |
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| Research Abstract |
We have attempted an ELISA test for sera of patients with acute and chronic silent hepatitis B in order to detect specific antibodies using X protein and anti-X protein. Anti-X protein is an protein encoded by the complementary strand of the minus X strand and is composed of 161 amino acids. We have synthesized many synthetic peptides for the two proteins by the analysis of antigenicity. These peptides were used for the antigens of ELISA.the control comprised polyclonal antibodies for the synthetic peptides and normal healthy serum samples. As a result, the sera of the silent hepatitis B tended to show higher titers than those of the normal control for the peptides. Hower, this ELISA system does not seem to be directly used for the clinical trial. At present, the nested PCR method for the amplification of serum HBVDNA is the most sensitive method for the detection of silent hepatities B.If the liver sample is availble from patients with silent hepatitis, the immunostaining for HBsAg may be a reliable and sensitive method for detection of silent B virus.
Silent HBVDNA is characterized by an 8-nucleotide deletion of the X region. We have cloned the full genome constructed its head-to-tail tandem repeat of the silent HBVDNA.We have transfected silent HBVDNA in vitro to an established cell line dervied from a human hepatocellular carcinoma using the wild-type (HBsAg-positive) HBVDNA as a control. As a result, the amount of HBsAg and HBeAg secreted into the culture supematants was decreased to 1/3-1/5 compared those of the wild-type HBVDNA.The suppression of gene expression of silent HBVDNA was confirmed in vitro as well.
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