| Project/Area Number |
17510047
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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 |
Risk sciences of radiation/Chemicals
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| Research Institution | The University of Tokushima |
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Principal Investigator |
MAEZAWA Hiroshi The University of Tokushima, School of Medicine, Professor, 医学部, 教授 (00138653)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | microbeam / x-rays / lung epithelial cells / bystander effect / DNA damage / nitric oxide / bioimaging / nitric oxide synthase |
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| Research Abstract |
1. Induction of DNA double strand breaks (dsb) on lung epithelial and fibroblast cells irradiated with monochromatic x-ray microbeam (5.35 keV, 10μm×10μm) : Phosphorylated H2AX (γH2AX) was observed as γ H2AX foci in a microbeam-irradiated human bronchial epithelial cell (NHBE) nuclei. Exposure (0〜1000R) dependence of foci induction was observed. Total fluorescence of NBS1 foci in fibroblast cells (NHLF) increased also depending on exposure of microbeam x-rays. It was shown that microbeam irradiation on cell nuclei produced dsb in a target area.
2. Bio-imaging of nitric oxide (NO) in lung cells using DAF-2DA dye : In the absence of contact of neighboring NHBE, the fluorescence derived from NO-DAF complex was not observed in unirradiated NHBE. When a small number of NHBE in a dish was irradiated cell nuclei as a target, in the presence of contact of neighboring cells, NO-DAF fluorescence appeared and its intensity per cells increased at 24 h after irradiation (500R) as compared at 0 h. It is suggested that some unknown factors emitted from irradiated cells caused NO production in unirradiated one.
3. Induction of nitric oxide syntheses (NOS) in cells : Inducible NOS (iNOS) in cells was detected by immunofluorescence technique with iNOS anti-body. No induction of iNOS in cells after sham microbeam irradiation was observed. When NHBEs were grown in the presence of cell-to-cell contact and then a small number of cells in a dish was irradiated with microbeam, the number of cells showing fluorescence derived from iNOS anti-body increased at 24 hours after irradiation as compared at 0 h.
4. It was suggested that the microbeam irradiation of cell nuclei induced bystander effect concerning NO production in lung epithelial cells in the presence of cell-to-cell contact..
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