| Project/Area Number |
16590494
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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 |
Hygiene
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| Research Institution | University of Occupational and Environmental Health, Japan |
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Principal Investigator |
OGAMI Akira University of Occupational and Environmental Health, Japan, Institute of Industrial Ecological Sciences, Associate Professor, 産業生態科学研究所, 助教授 (40301692)
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| Co-Investigator(Kenkyū-buntansha) |
TANAKA Isamu University of Occupational and Environmental Health, Japan, Institute of Industrial Ecological Sciences, Professor, 産業生態科学研究所, 教授 (00038035)
MORIMOTO Yasuo University of Occupational and Environmental Health, Japan, Institute of Industrial Ecological Sciences, Professor, 産業生態科学研究所, 教授 (30258628)
OYABU Takako University of Occupational and Environmental Health, Japan, Institute of Industrial Ecological Sciences, Research Associate, 産業生態科学研究所, 助手 (20320369)
MURAKAMI Masahiro University of Occupational and Environmental Health, Japan, Institute of Industrial Ecological Sciences, Research Associate, 産業生態科学研究所, 助手 (60373156)
HIROHASHI Masami University of Occupational and Environmental Health, Japan, Institute of Industrial Ecological Sciences, Research Assistant, 産業生態科学研究所, 教務職員 (50389475)
大和 浩 産業医科大学, 産業生態科学研究所, 助教授 (90248592)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2006: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2005: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | nanoparticle / carbon nanotube / intratracheal instillation / BAL / carbon graphite / pulmonary fibrosis / lung cancer / 気管支肺胞洗浄液 / カーボングアファイト |
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| Research Abstract |
This study aimed to evaluate the pulmonary effect of carbon nanotube (CNT) by intratracheal instillation to rats. Nanoparticles have specific optical and electric properties. In general, nanoparticles have a tendency to agglomerate, therefore, it is necessary to prevent the agglomeration of the nanoparticles as possible when we evaluate the toxicity. Before instillation, we confirmed the dispersion of the nanotubes with the surface active agent (Triton X) under scanning electron microscopy.
We instilled CNT (with 0.5% Triton X saline) intratracheally at the concentration of 40 μg to Wistar male rats (8 weeks old). Crystalline silica (median diameter 0.8 μm) was also instilled as a reference material. Control rats were instilled only saline with Triton X. Autopsy was done at 3days, 1 week, 1 month, 3 months, and 6 months after instillation. Bronchoalveolar lavage fluid (BALF), blood, lung tissue were extracted from each rat.
Total cell counts in BALF showed that the number of cells was increased at the early phase after instillation of CNT, however, no significant difference were observed at 3months or later time period. For the percentage of PMN, the significant increase was observed in CNT and silica instilled groups at 3 days and at 3 months later. We examined pulmonary inflammation in each by the point counting method (PCM). As six images digitally captured under the light microscopy were examined per specimen, 1800 points (300 points x 6 images) were examined in each lung section. We counted the number of points that had accumulated inflammatory cells and the number of air spaces. There were no significant difference in inflammatory changes in lung section determined by point counting method between exposure group (CNT and crystalline silica) and control. In conclusion, CNT did not show the severe pulmonary effect by intratracheal instillation to rats at the concentration of 40 μg.
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