Objective: To explore the changes in ribosomal DNA copy number in peripheral blood among patients with pneumoconiosis and its influencing factors, so as to provide insights into prevention and treatment of pneumoconiosis. Methods: Eighty-eight patients with pneumoconiosis who visited a designated hospital and 71 community residents with no history of pneumoconiosis or dust exposure were selected as the pneumoconiosis group and control group, and age, smoking history, drinking history and cumulative years of exposure to dust were collected through questionnaire surveys. The copy number of 45S rDNA and 5S rDNA was detected using real-time fluorescence quantitative PCR, and the differences between the two groups were compared. Factors affecting the copy number of 45S rDNA and 5S rDNA were identified by a multiple linear regression model. Results: The pneumoconiosis group had a median age of 56.00 (interquartile range, 15.25) and a mean cumulative dust exposure duration of (12.40±8.08) years, with 56.82% smoking and 62.50% drinking. The control group had a median age of 64.00 (interquartile range, 37.00) years, with 32.39% smoking and 26.76% drinking. The median copy number of 45S rDNA in the pneumoconiosis group was 1.29 (interquartile range, 0.59), which was lower than 2.10 (interquartile range, 1.88) in the control group; the median copy number of 5S rDNA in the pneumoconiosis group was 5.33 (interquartile range, 0.85), which was higher than 4.66 (1.34) in the control group (both P<0.05). Multiple linear regression analysis identified age (β=-0.034) and pneumoconiosis (β=-1.595) as factors affecting 45S rDNA copy number, age (β=-0.013) as a factor affecting 5S rDNA copy number, and age (β=0.018) as a factor affecting 5S rDNA copy number in the pneumoconiosis group (all P<0.05). Conclusions Compared with community residents with no history of pneumoconiosis or dust exposure, the copy number of 45S rDNA in peripheral blood among patients with pneumoconiosis is reduced and the copy number of 5S rDNA is increased.

Objective : To examine the diagnostic and prognostic value of long non-coding RNA (lncRNA) JPX in mesothelioma, so as to provide insights into diagnosis and prognosis of mesothelioma. Methods: Patients with clinically definitive diagnosis of mesothelioma from 2015 to 2019 that were sampled from asbestos processing plants in Zhejiang Province from 2015 to 2019 were recruited in the mesothelioma group, while healthy residents without asbestos exposure or asbestos-related diseases in the same area served as controls. Participants' demographics, pathologic diagnosis and imaging features were collected, and the expression of blood lncRNA JPX was detected using lncRNA microarrays. The diagnostic value of lncRNA JPX for mesothelioma was evaluated using the receiver operating characteristic (ROC) curve, and the correlation between lncRNA JPX expression and prognosis was examined among mesothelioma patients using survival analysis. Results: There were 17 subjects in the mesothelioma group, with a mean age of (65.71±8.36) years, and 34 subjects in the controls, with a mean age of (64.24±8.70) years. LncRNA microarray detected significantly high lncRNA JPX expression in mesothelioma patients, and higher blood lncRNA JPX expression was detected in the mesothelioma group than in the control group [median (interquartile range), 1.10 (1.31) vs. 0.89 (0.54); t'=-2.300, P=0.034]. The area under the ROC curve was 0.673 (95%CI: 0.507-0.839, P=0.046), and if the cutoff was 1.759, the sensitivity and specificity were 35.3% and 100.0%, respectively. Survival analysis showed no significant difference in the survival rate of mesothelioma patients between the high lncRNA JPX expression group and the low expression group (χ2=0.212, P=0.645). Conclusions LncRNA JPX overexpression is detected in the blood of patients with mesothelioma, and lncRNA JPX expression presents a diagnostic value for mesothelioma; however, it shows little prognostic value for mesothelioma.

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.

{L-End}Objective To analyze the effects of night shift work and overweight/obesity on blood pressure of workers in chemical fiber industry. {L-End}Methods A total of 1 004 workers of a chemical fiber factory were selected as the study subjects using convenient sampling method, and their blood pressure and body mass index were measured. Multiple linear regression model was used to analyze the relationship between night shift work and blood pressure, and multiple logistic regression was used to assess the independent impact and combined impact of night shifts and overweight/obesity on the risk of hypertension. {L-End}Results Compared with the non-night shift workers, the prevalence of hypertension in night shift workers was increased (5.3% vs 13.0%, P<0.05), with elevated systolic and diastolic blood pressure (both P<0.05). The results of multiple linear regression analysis showed that the systolic blood pressure and diastolic blood pressure of the night shift workers were higher than those of the non-night shift workers (both P<0.05), and the systolic blood pressure and diastolic blood pressure of overweight/obesity workers were higher than those of non-overweight/obesity workers (both P<0.01). The results of multiple logistic regression analysis showed that the risk of hypertension in night shift workers and overweight/obesity workers was higher than that in non-night shift workers and non-overweight/obesity workers [odds ratio (OR) and 95% confidence interval (CI) were 2.49 (1.04-5.99) and 2.65 (1.77-3.95), both P<0.05]. Night shift work and overweight/obesity showed a synergistic effect on blood pressure of workers. Compared to non-overweight/obesity non-night shift workers, overweight/obesity night shift workers had a higher risk of hypertension (OR=4.93, 95%CI: 1.70-14.29, P<0.01). {L-End}Conclusion Night shift work could lead to elevated blood pressure in workers in the chemical fiber industry, which is a potential risk factor for hypertension. The synergistic effect of night shift work and overweight/obesity may contribute to the increased risk of hypertension.

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.

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.

Objective: To investigate the effect of chrysotile exposure on ribosomal DNA (rDNA) copy number and DNA damage response, so as to provide insights into the mechanism of asbestos-induced carcinogenesis. Methods: Human pleural mesothelial MeT-5A cells were treated with chrysotile suspensions at doses of 1.25, 2.5 and 5 μg/cm2 (low-, medium-, high-dose group), while PBS served as controls. MeT-5A cells were harvested 6, 24, 48 and 72 h post-treatment, and the rDNA copy numbers and the BIRC5, HRAS, GINS4 and RRM2 mRNA expression were determined using a quantitative real-time PCR (qPCR) assay. The apoptosis of MeT-5A cells and DNA damage were detected using Muse cell analyzer. The rDNA copy numbers, DNA damage responses and BIRC5, HRAS, GINS4 and RRM2 mRNA expression were compared in MeT-5A cells treated with different doses of chrysotile suspensions. Results: There were significant differences in 45S rDNA copy numbers among low-, medium-, high-dose groups and the control groups 6, 48 and 72 h post-treatment with chrysotile suspensions, and significantly lower 45S rDNA copy numbers were measured in low-, medium- and high-dose groups than in the control group 6 h post-treatment, while significantly higher 45S rDNA copy numbers were found in the high-dose group than in low- and medium-dose groups 48 and 72 h post-treatment (all P<0.05). There were significant differences in 5S rDNA copy numbers among low-, medium-, high-dose groups and the control groups 24, 48 and 72 h post-treatment with chrysotile suspensions, and significantly lower 5S rDNA copy numbers were measured in medium- and high-dose groups than in the control group 24 and 48 h post-treatment, while significantly lower 5S rDNA copy numbers were found in medium- and high-dose groups than in the low-dose group 24, 72 h post-treatment (all P<0.05). There were significant differences in the overall apoptotic rate of MeT-5A cells among groups at different time points, and the overall apoptotic rate of MeT-5A cells were significantly higher in medium- and high-dose groups than in the control group (all P<0.05), with late-stage apoptosis predominantly detected. There were significant differences in the rates of ATM activation and DNA double-strand break in MeT-5A cells among groups 72 h post-treatment, and higher rates of ATM activation and DNA double-strand break were measured in medium- and high-dose groups than in the control group (all P<0.05). In addition, there were significant differences in the relative mRNA expression of BIRC5, HRAS, GINS4 and RRM2 genes among groups 24 and 48 h post-treatment, and significantly lower BIRC5, HRAS, GINS4 and RRM2 mRNA expression was quantified in medium- and high-dose groups than in the control group (all P<0.05). Conclusion Exposure to chrysotile may induce rDNA copy number variations and altered expression of nucleolar proteins in human pleural mesothelial cells, which may be involved in the regulation of DNA damage responses.

Objective:To explore the occupational stress status and influencing factors of workers in a textile factory in Zhejiang Provice.Methods:In October 2018, 505 workers from a textile factory in Zhejiang Province were selected as research objects by convenient sampling method. A total of 505 questionnaires were distributed, 495 of which were effective and the effective recovery rate was 98.0%. Job Content Questionnaire (JCQ) and Effort Reward Imbalance Questionnaire (REI) were used to investigate textile workers' occupational stress and analyze its influencing factors. The differences of the composition ratio of different groups were tested by χ 2 test. The influencing factors such as age, gender and occupation on occupational stress were analyzed by multivariate logistic regression. Results:ERI analysis results showed that the high and low occupational stress accounted for 30.1% and 69.9%, respectively. The differences of occupational stress among workers of different job types and working ages were statistically significant ( P<0.05) . The detection rates of high occupational stress of paper workers and spinners were 47.8% (11/23) and 44.8% (30/67) , respectively, higher than other jobs. The detection rate of high occupational stress for workers with more than 5 years of service was 46.4% (13/28) . The results of JCQ analysis showed that there was no statistical significance in the differences of daily working hours and length of service between different gender, education levels, types of work patterns, and occupational stress ( P>0.05) . Job types had significant effects on the occupational stress defined by ERI ( P<0.05) , the risk of occupational stress was 2.151 times than that of the coiler. Conclusion:There are significant differences in occupational stress risk among workers of different types of work in textile industry, so different measures should be taken to prevent and control occupational stress in different jobs.

Objective:To explore the occupational stress status and influencing factors of workers in a textile factory in Zhejiang Provice.Methods:In October 2018, 505 workers from a textile factory in Zhejiang Province were selected as research objects by convenient sampling method. A total of 505 questionnaires were distributed, 495 of which were effective and the effective recovery rate was 98.0%. Job Content Questionnaire (JCQ) and Effort Reward Imbalance Questionnaire (REI) were used to investigate textile workers' occupational stress and analyze its influencing factors. The differences of the composition ratio of different groups were tested by χ 2 test. The influencing factors such as age, gender and occupation on occupational stress were analyzed by multivariate logistic regression. Results:ERI analysis results showed that the high and low occupational stress accounted for 30.1% and 69.9%, respectively. The differences of occupational stress among workers of different job types and working ages were statistically significant ( P<0.05) . The detection rates of high occupational stress of paper workers and spinners were 47.8% (11/23) and 44.8% (30/67) , respectively, higher than other jobs. The detection rate of high occupational stress for workers with more than 5 years of service was 46.4% (13/28) . The results of JCQ analysis showed that there was no statistical significance in the differences of daily working hours and length of service between different gender, education levels, types of work patterns, and occupational stress ( P>0.05) . Job types had significant effects on the occupational stress defined by ERI ( P<0.05) , the risk of occupational stress was 2.151 times than that of the coiler. Conclusion:There are significant differences in occupational stress risk among workers of different types of work in textile industry, so different measures should be taken to prevent and control occupational stress in different jobs.

OBJECTIVE: To optimize DNA library construction in non-crosslinked chromatin immunoprecipitation coupled with next-generation sequencing (Native ChIP-seq) to obtain high-quality Native ChIP-seq data. METHODS: Human nasopharyngeal carcinoma HONE1 cell lysate was digested with MNase for release of the nucleosomes, and the histone-DNA complexes were immunoprecipitated with specific antibodies. The protein component in the precipitate was digested with proteinase K followed by DNA purification; the DNA library was constructed for sequence analysis. RESULTS: Compared with the conventional DNA library construction, Tn5 transposase method allowed direct enrichment of the target DNA after Tn5 fragmentation, which was simple, time-saving and more efficient. The IGV visualized map showed that the information obtained by the two library construction methods was consistent. The sequencing data obtained by the two methods revealed more signal enrichment with Tn5 transposase library construction than with the conventional approach. H3K4me3 ChIP results showed a good reproducibility after Tn5 transposase library construction with a signal-to-noise ratio above 50%. CONCLUSIONS Tn5 transposase method improves the efficiency of DNA library construction and the results of subsequent sequence analysis, and is especially suitable for detecting histone modification in the DNA to provide a better technical option for epigenetic studies.
Chromatin Immunoprecipitation ; DNA ; Gene Library ; High-Throughput Nucleotide Sequencing ; Humans ; Reproducibility of Results ; Sequence Analysis, DNA