RESUMO
Objective@#To investigate the effect of ribosomal DNA (rDNA) copy number variation caused by hexavalent chromium exposure on DNA damage response in different cell lines, so as to provide insights into the involvement of hexavalent chromium-induced rDNA copy number variation in DNA damage responses. @*@#Methods Human lung epithelial BEAS-2B cells and human embryonic lung MRC-5 cells were treated with 2 μmol/L potassium dichromate for 24 hours, and then cells were transferred to fresh media for further incubation, while cells treated with the same volume of phosphate buffer solution served as controls. Cells treated with potassium dichromate for 24 hours, and 3 and 7 days post-detoxification, were harvested, and rDNA copy number was quantified in cells using a quantitative fluorescent real-time PCR assay. Cell cycle, apoptosis and DNA damage were detected using a Muse cell analyzer, and the DNA damage was evaluated with the proportion of ataxia telangiectasia-mutated (ATM) gene activation, proportion of double-strand DNA breaks and the percentage of the H2A.X variant histone phosphorylatio.@*@# Results The 45S and 5S rDNA copy numbers of were significantly higher in MRC-5 cells than in BEAS-2B cells [(1.54±0.26) vs. (1.02±0.18), P<0.05; (6.97±1.07) vs. (3.00±0.15), P<0.05]. The 45S rDNA copy number was lower in MRC-5 cells 3 days post-detoxification (0.80±0.04) than in controls (P<0.05), and was higher in BEAS-2B cells 3 days post-detoxification (1.43±0.07) than in controls (P<0.05) . G0/G1 phase arrest was found in MRC-5 cells 24 hours post-treatment, and the apoptotic rates were significantly higher in MRC-5 cells 3 and 7 days post-detoxification than in controls [(11.53±1.53)%, (18.33±0.70)% vs. (3.53±0.93)%, P<0.05]. The overall apoptotic rates 24 hours post-treatment and 3 days post-detoxification [(2.80±0.17)%, (3.33±0.57)% vs. (1.53±0.61)%, P<0.05], proportion of ATM gene activation 3 days post-detoxification [(3.37±0.67%) vs. (1.18±0.22)%, P<0.05], proportion of double-strand DNA breaks 3 days post-detoxification [(4.45±0.85)% vs. (0.97±0.21)%, P<0.05] and percentage of the H2A.X variant histone phosphorylation 3 days post-detoxification [(1.68±0.56)% vs. (0.29±0.06)%, P<0.05] in BEAS-2B cells were higher than in controls. @*Conclusions@#Hexavalent chromium-induced rDNA copy number variation affects DNA damage response in different cell lines. A stronger DNA damage response is found in BEAS-2B cells with a low rDNA copy number, and a relative stable response is observed in MRC-5 cells with a high rDNA copy number.
RESUMO
Objective @#To analyze the survival of patients with malignant mesothelioma, so as to provide insights into the management of malignant mesothelioma.@*Methods @#Totally 36 patients with malignant mesothelioma admitted to Cixi Third People’s Hospital from October 2012 to January 2021 were enrolled, and the demographic features, exposure to asbestos, and diagnosis and treatment were retrospectively reviewed. The survival rate and median survival time were calculated with the life-table method, and the factors affecting the survival rate of malignant mesothelioma were identified using the Kaplan-Meier estimate and log-rank test.@*Results @#The 36 patients with malignant mesothelioma included 6 men ( 16.67% ) and 30 women ( 83.33% ), and had a median age of 61 ( interquartile range, 14 ) years. There were 30 cases with pleural malignant mesothelioma ( 83.33% ) and 6 cases with peritoneal malignant mesothelioma ( 16.67% ), 32 cases ( 88.89% ) with a history of occupational exposure to asbestos, and 26 cases ( 72.22% ) receiving palliative treatment. The 1-, 2- and 3-year cumulative survival rates were 30%, 15% and 3%, respectively, and the median survival time was 0.71 years. In addition, there were no significant differences in the survival period among patients with malignant mesothelioma in terms of gender, age, route of asbestos exposure, duration of asbestos exposure, pathogenic site and treatment regimens ( P>0.05 ).@*Conclusion @#The 36 patients with malignant mesothelioma had a median survival period of 0.71 years, and no association was found between the survival period and asbestos exposure or pathogenic site.
RESUMO
Objective @#To examine the effect of asbestos exposure on oxidative stress, so as to provide insights into the elucidation of pathogenesis and management of asbestos-related diseases. @*Methods @#Totally 245 subjects were recruited from an asbestos manufacturing area in Zhejiang Province, and their gender, age and history of asbestos exposure were collected through a questionnaire survey. The serum levels of 8-hydroxy-2'deoxyguanosine ( 8-OHdG ), glutathione ( GSH ), malondialdehyde ( MDA ), superoxide dismutase ( SOD ) and total antioxidative capacity ( TAOC ) were measured using an enzyme-linked immunosorbent assay ( ELISA ), and the levels of catalase ( CAT ), peroxiredoxin 2 ( PRX2 ), SOD1, SOD2 and thioredoxin-1 ( TRX1 ) were detected in peripheral white blood cells ( WBCs ) using a liquid-chip assay. Multivariable linear regression analysis was performed to identify the association between asbestos exposure and oxidative stress parameters. @*Results @#There were 50 subjects without a history of asbestos exposure (unexposed group), 102 subjects with asbestos exposure for less than 10 years ( AE<10-year group ) and 93 subjects with asbestos exposure for 10 years and more ( AE≥10-year group ). No significant differences were found among the three groups in terms of age, gender, proportion of smokers or proportion of alcohol consumers ( P>0.05 ). Significantly higher 8-OHdG and MDA in serum, and higher PRX2 in peripheral WBCs were detected in the AE≥10-year group than in the unexposed group ( P<0.05 ); lower GSH and TAOC in serum, and lower CAT in peripheral WBCs were detected in the AE≥10-year group than in the unexposed group ( P<0.05 ); higher 8-OHdG and MDA in serum, and higher PRX2 in peripheral WBCs were detected in the AE≥10-year group than in the AE<10-year group ( P<0.05 ). Multivariable linear regression analysis showed that asbestos exposure significantly correlated with 8-OHdG, MDA and TAOC in serum, and CAT and PRX2 in peripheral WBCs ( P<0.05 ). @*Conclusion @#Asbestos exposure may induce the oxidative stress damage, suggesting that oxidative stress may be involved in asbestos-related diseases.
RESUMO
@#Pneumoconiosis is a serious occupational disease in China. Early imaging examination is one of the important measures for the diagnosis, treatment and prevention of pneumoconiosis. Digital radiography (DR) and computed tomography (CT) play an important role in the screening and diagnosis of pneumoconiosis, as well as the recent rise of artificial intelligence (AI) technology. This paper reviews the latest progress in technical parameter debugging and quality control of DR, optimization of AI computer-aided system and CT-aided diagnosis of pneumoconiosis, summarizes the advantages and problems in the application of the three technologies, providing research directions for imaging diagnosis of pneumoconiosis.