Publications by authors named "Kyohei Misumi"
We conducted a two-year inhalation study of butyraldehyde using F344/DuCrlCrlj rats. The rats were exposed to 0, 300, 1,000 and 3,000 ppm (v/v) for 6 hr/day, 5 days/ week for 104 weeks using whole-body inhalation chambers. The incidence of squamous cell carcinoma of the nasal cavity was increased in the 3,000 ppm groups of both male and female rats, with Fisher's exact test and the Peto test indicating that the incidence was significant.
View Article and Find Full Text PDFArticle Synopsis
- Six workers in a Japanese chemical plant developed interstitial lung diseases linked to inhalation of cross-linked water-soluble acrylic acid polymers (CWAAPs), prompting this study on lung damage in rats.
- The study involved exposing male rats to CWAAPs through inhalation and intratracheal instillation, analyzing lung tissues and fluids for damage and cellular responses.
- Results showed that both single and repeated exposures led to alveolar injury and changes in lung tissue, with some lesions healing and others progressing to more severe conditions like alveolitis.
Article Synopsis
- The study aimed to assess the cancer-causing effects of 2-bromopropane (2-BP) in rats through inhalation exposure over two years.
- Male and female F344 rats were exposed to varying concentrations of 2-BP, with those exposed to the highest level experiencing severe health issues and dying from tumors.
- The research found a significant increase in various types of tumors in the rats, suggesting that 2-BP poses a risk of being a carcinogen to humans as well.
Background: Most toxicological studies on titanium dioxide (TiO) particles to date have concentrated on carcinogenicity and acute toxicity, with few studies focusing of pneumoconiosis, which is a variety of airspace and interstitial lung diseases caused by particle-laden macrophages. The present study examined rat pulmonary lesions associated with pneumoconiosis after inhalation exposure to TiO nanoparticles (NPs).
Methods: Male and female F344 rats were exposed to 6.
With the rapid development of alternative methods based on the spirit of animal welfare, the publications of animal studies evaluating endpoints such as cancer have been extremely reduced. We performed a 26-week inhalation exposure studies of titanium dioxide nanoparticles (TiO NPs) using CByB6F1-Tg(HRAS)2Jic (rasH2) mice model for detecting carcinogenicity. Male and female rasH2 mice were exposed to 2, 8 or 32 mg/m of TiO NPs for 6 h/day, 5 days/week for 26 weeks.
View Article and Find Full Text PDFArticle Synopsis
- In Japan, six workers exposed to a chemical called CWAAP suffered from various lung diseases, prompting research on its health impacts and occupational safety standards.
- A study on rats exposed to different concentrations of CWAAP-A revealed that while lower doses allowed tissues to recover after 13 weeks, higher doses caused irreversible lung damage.
- The study found a gender difference in recovery rates between male and female rats, highlighting the importance of macrophages in mitigating acute lung effects from CWAAP-A exposure.