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In this study, the effect of ionizing radiation on 8-hydroxy-2′-deoxyguanosine (8-OHdG) in human peripheral blood was investigated. Blood samples were collected from 230 radiation workers and 8 patients who underwent radiotherapy for population study. Blood samples from 2 healthy individuals were irradiated with different X-ray doses for in vitro experiment, and levels of 8-OHdG in serum and cell culture supernatants were assessed by enzyme-linked immunosorbent assay. Observations demonstrated the positive relationships between serum 8-OHdG level and radiation dose and working period were observed, and serum 8-OHdG levels were higher among interventional radiation workers than among other hospital radiation workers. In addition, 8-OHdG yields in supernatants increased, peaked at 3 Gy of radiation dose, and then decreased with further increases in radiation; the dose–response curve obtained fitted a polynomial function. By contrast, a similar trend was not found in radiotherapy patients. The present study suggests that 8-OHdG may be a useful biomarker reflecting oxidative damage among workers occupationally exposed to low-dose radiation.

Osteoarthritis (OA) is a disease characterized by cartilage damage and abnormal remodeling of subchondral bone. Our previous study showed that in the early stage of OA, knee loading exerts protective effects by suppressing osteoclastogenesis through Wnt signaling, but little is known about loading effects at the late OA stage. Endoplasmic reticulum (ER) stress and autophagy are known to be involved in the late OA stage. We determined the effects of mechanical loading on ER stress and autophagy in OA mice. One hundred seventy‐four mice were used for a surgery‐induced OA model. In the first set of experiments, 60 mice were devoted to evaluation of the role of ER stress and autophagy in the development of OA. In the second set, 114 mice were used to assess the effect of knee loading on OA. Histologic, cellular, microcomputed tomography, and electron microscopic analyses were performed to evaluate morphologic changes, ER stress, and autophagy. Mechanical loading increased phosphorylation of eukaryotic translation initiation factor 2α(eIF2α) and regulated expressions of autophagy markers LC3II/I and p62. Osteoarihritic mice also exhibited an elevated ratio of calcified cartilage to total articular cartilage (CC/TAC), and synovial hyperplasia with increased lining cells was found. At the early disease stage, subchondral bone plate thinning and reduced subchondral bone volume fraction (B.Ar/T.Ar) were observed. At the late disease stages, subchondral bone plate thickened concomitant with increased B.Ar/T.Ar. Mice subjected to mechanical loading exhibited resilience to cartilage destruction and a correspondingly reduced Osteoarthritis Research Society International score at 4 and 8 wk, as well as a decrease in synovitis and CC/TAC. While chondrocyte numbers in the OA group was notably decreased, mechanical loading restored chondrogenic differentiation. These results demonstrate that mechanical loading can retard the pathologic progression of OA at its early and late stages. The observed effects of loading are associated with the regulations of ER stress and autophagy.—Zheng, W., Li, X., Liu, D., Li, J., Yang, S., Gao, Z., Wang, Z., Yokota, H., Zhang, P. Mechanical loading mitigates osteoarthritis symptoms by regulating endoplasmic reticulum stress and autophagy. FASEB J. 33,4077–4088 (2019). http://www.fasebj.org

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Purpose This study aims to examine the impact of various dimensions of product market competition on accounting conservatism particularly in the wake of regulatory changes and varying ownership structures in China. Design/methodology/approach This study examines impact of product market competition on accounting conservatism by using conservatism measure of Khan and Watts (2009) and measures for important dimensions of competition such as competition intensity, non-price competition and competition from existing rivals and potential entrants. Findings The findings suggest that competition intensity and non-price competition result in higher conservatism. This study also advocates that industry leaders exhibit lower conservatism as compared to industry followers. Moreover, the authors document positive association between competition from existing/potential rivals and accounting conservative. These findings reveal that regulatory changes (International Financial Reporting Standards adoption) influence the effect of various dimensions of competition on conservatism. The authors also propose that financial reporting practices of state-owned enterprises are not influenced by competition. However, competition affects financial reporting (conservatism) when institutional or managerial ownership is higher. Originality/value The authors document that strategic considerations shape conservative financial reporting decisions of the managers. This study also advocates that when regulatory changes affect the influence of competitive pressure on the conservative reporting decisions of the mangers. Findings also suggest that unlike state ownership, institutional as well as managerial ownership affects the influence of competition on managerial decisions like conservative financial reporting. These results are robust to various alternative measures of conservatism.