Publications by authors named "Yohei Mizuguchi"

In order to investigate the pulmonary toxicity of titanium dioxide (TiO) nanoparticles, we performed an intratracheal instillation study with rats of well-dispersed TiO nanoparticles and examined the pulmonary inflammation and histopathological changes in the lung. Wistar Hannover rats were intratracheally administered 0.2 mg (0.

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Multi-walled carbon nanotubes (MWCNTs) are interesting new materials, but there is some concern about their harmfulness due to their fibrous nature. To determine the difference in the biological effects of MWCMTs by fiber length, we prepared two MWCNT samples from one bulk sample. One consisted of cut up short fibers (Short; average length=0.

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Article Synopsis
  • This study examined the pulmonary toxicity of nickel oxide (NiO) nanoparticles in male Wister rats through both inhalation and intratracheal instillation methods over a 4-week period.
  • Researchers measured inflammation in the lungs by analyzing polymorphonuclear neutrophils (PMNs) in bronchoalveolar lavage fluid, specifically targeting the relationship between surface area doses of NiO and PMN response.
  • Findings indicated that PMN responses were linked to surface area rather than mass of NiO particles, suggesting a potential approach to predict how aerosol concentrations of other nanomaterials could lead to similar inflammatory responses in the lungs.
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Objective: In our previous study, we reported that the micron-sized nickel oxide nanoparticle agglomerates induced neutrophil infiltration and the gene expression of the cytokine-induced neutrophil chemoattractant (CINC)-2αβ in a rat lung. In this study, we examined the expression of the CINCs family in the lung using the same rat model exposed to micron-sized nickel oxide nanoparticle agglomerates.

Methods: The count median diameter of nickel oxide nanoparticle agglomerates suspended in saline was 1.

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It is important to conduct a risk assessment that includes hazard assessment and exposure assessment for the safe production and handling of newly developed nanomaterials. We conducted an inhalation study of a multi-wall carbon nanotube (MWCNT) as a hazard assessment. Male Wistar rats were exposed to well-dispersed MWCNT for 4 weeks by whole body inhalation.

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Single-wall carbon nanotubes (SWCNTs) were well-dispersed by ultrasonication to conduct an inhalation study. SWCNTs were generated using a pressurised nebuliser with liquid suspension of SWCNTs. Wistar rats were exposed to the well-dispersed SWCNT (diameter of bundle: 0.

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Multi-walled carbon nanotubes (MWCNTs), dispersed in suspensions consisting mainly of individual tubes, were used for intratracheal instillation and inhalation studies. Rats intratracheally received a dose of 0.2 mg, or 1 mg of MWCNTs and were sacrificed from 3 days to 6 months.

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Objective: We examined the pulmonary toxicity of nickel oxide nanoparticle agglomerates in the rat lung following an intratracheal instillation.

Methods: The weighted average surface primary diameter of nickel oxide nanoparticles was 8.41 nm, and the count median diameter of nickel oxide nanoparticle agglomerates suspended in saline was 1.

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