1998 Fiscal Year Final Research Report Summary
Magnetometoric Evaluation of Cellular Toxicity of Semiconductor Material
| Project/Area Number |
08457118
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | KITASATO UNIVERSITY |
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Principal Investigator |
AIWAZA Yoshiharu Kitasato University School of Medicine, Department of Preventive Medicine and Public Health, Professor, 医学部, 教授 (10124926)
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| Co-Investigator(Kenkyū-buntansha) |
KARUBE Hitomi Kitasato University School of Medicine, Assistant Professor, 医学部, 講師 (10161259)
KOTANI Makoto Tokyo Denki University Faculty of Engineering, Professor, 工学部, 教授 (60057205)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Semiconductor / Magnetometry / Microelectronics / Cellular toxicity / Gallium Arsenide |
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| Research Abstract |
Gallium arsenide(GaAs) has led to the development of electro-optical devices such as light emitting diodes and semiconductor lasers. Several reports point to pulmonary exposure to GaAs dust as a potential occupational health hazard.
A rapid decrease in the magnetic field after magnetization of the thorax of animals intratracheally instilled with magnetic particles has been noted and designated as "relaxation't. This phenomenon indicates a rapid decrease of remanent magnetic field following magnetization of the lungs due to random rotation of phagocytosed iron oxide particles in macrophages. Delayed relaxation and clearance of iron oxide have been observed in rabbits exposed to GaAs.
In this study, alveolar macrophages adhered to glass in the bottom of wells were exposed to iron oxide 60mug with or without GaAs 2Omug/ml in culture medium. Rapid relaxation was observed in the sample of GaAs free medium, whereas relaxation for the specimen with GaAs was delayed. GaAs impaired relaxation dose-dependently. Since addition of Ga_20_3 into the medium did not affect relaxation, arsenic is considered affecting relaxation. LDH release from cells also indicated toxic effect of GaAs on macrophages. Transmission electron microscopy revealed alterations of cell membrane, organelles in macrophages exposed to GaAs.
Other chemicals such as limestone, chrysotile fiber, titanium dioxide, silicon carbide were tested with the same methods and all substances except limestone showed appreciable in vitro delay of relaxation by this method.
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