Purpose: To understand the mechanisms of life-shortening due to early neoplastic death caused by chronic low dose-rate (LDR; 20 mGy/22 h/day) radiation which accumulates to a high dose (HD; 8 Gy) (LDR/HD) as reported previously.
Materials And Methods: Female B6C3F(1) mice were continuously exposed to LDR/HD gamma-rays under specific-pathogen-free (SPF) conditions for 400 days. OV3121 cells, which were derived from an ovarian granulosa cell tumour that arose in irradiated B6C3F(1) mice, were inoculated into LDR/HD irradiated and age-matched non-irradiated control mice. The transplantability of tumour cells as well as T cell subsets and the proliferative activities of T cells were compared between irradiated and non-irradiated mice.
Results: We found that tumour formation of subcutaneously inoculated tumour cells occurred earlier in irradiated mice than in non-irradiated mice. Proliferative activity of draining lymph node lymphocytes against transplanted tumour cells as well as allogeneic mixed lymphocyte reactions were significantly reduced in irradiated mice compared to non-irradiated mice.
Conclusions: These results suggest that decreased tumour-specific immune response due to LDR/HD irradiation may enhance tumorigenesis resulting in life-shortening of mice after chronic LDR/HD irradiation.
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http://dx.doi.org/10.3109/09553002.2010.545861 | DOI Listing |
J Toxicol Pathol
January 2025
Laboratory of Veterinary Pathology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara-shi, Kanagawa 252-5201, Japan.
Amyloidosis is characterized by the extracellular deposition of insoluble protein fibrils that cause cellular damage and dysfunction in organs and tissues. Multiple types of amyloidosis and their causative precursor proteins have been identified in humans and animals. In toxicological studies, a high incidence of spontaneous amyloidosis has been reported in CD-1 mice; however, the precursor protein responsible remains unclear.
View Article and Find Full Text PDFEnviron Mol Mutagen
November 2024
General and Genetic Toxicology, Charles River Laboratories, Ashland, Ohio, USA.
Radiat Prot Dosimetry
November 2024
Department of Radiobiology, Institute for Environmental Sciences, 2-121 Hacchazawa, Rokkasho, Aomori 039-3213, Japan.
The purpose of the study was to determine whether environmental enrichments (EE) can mitigate the adverse effects of chronic low-dose-rate radiation exposure in mice. Female B6C3F1 mice were continuously exposed to 20 mGy d-1 gamma-rays under specific-pathogen-free conditions since 8 weeks of age for 400 d. After completion of the radiation exposure, OV3121 cells, derived from an ovarian granulosa cell tumor, were inoculated subcutaneously alongside age-matched non-irradiated control mice.
View Article and Find Full Text PDFToxic Rep Ser
October 2024
Division of Translational Toxicology, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.
Stachybotrys chartarum, also known as "black mold," is a cellulolytic saprophyte with a worldwide distribution. Public concern for potential illnesses associated with water-damaged indoor environments has been heightened since the report of pediatric acute idiopathic pulmonary hemorrhage/hemosiderosis cases in the United States and following recent natural disasters. Although mycotoxicosis and pulmonary immunological endpoints have been previously examined, the systemic toxicity following subchronic inhalation of viable S.
View Article and Find Full Text PDFCells
August 2024
JAC Co., Ltd., 1-2-7 Higashiyama, Meguro, Tokyo 153-0043, Japan.
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