Objective:To investigate the role of connective tissue growth factor (CTGF) and PI3K/Akt signaling pathways in paraquat (PQ) -induced alterations in alveolar epithelial cell mesenchymalization (EMT) .Methods:In February 2023, RLE-6TN cells were divided into 2 groups, which were set as uncontaminated group and contaminated group (200 μmol/L PQ), and cellular EMT alteration, CTGF and PI3K/Akt signaling pathway related molecules expression were detected by cell scratch assay, qRT-PCR and western-blot assay. Using shRNA interference technology to specifically inhibit the expression of CTGF, RLE-6TN cells were divided into four groups: control group, PQ group (200 μmol/L PQ), interference group (transfected with a plasmid with shRNA-CTGF+200 μmol/L PQ), and null-loaded group (transfected with a plasmid with scramble- CTGF+200 μmol/L PQ), qRT-PCR and western blot were used to examine the alteration of the cellular EMT and the expression of molecules related to the activity of PI3K/Akt pathway. The PI3K/Akt signaling pathway was blocked by the PI3K inhibitor LY294002, and the expression of EMT-related molecules in cells of the control group, PQ group (200 μmol/L PQ), and inhibitor group (200 μmol/L PQ+20 μmol/L LY294002) was examined by qRT-PCR and western blot.The t-test was used to compare the differences between the two groups, while the analysis of variance (ANOVA) was applied to compare the differences among multiple groups. For further pairwise comparisons, the Bonferroni method was adopted.Results:The results of cell scratch test showed that compared with the uncontaminated group, RLE-6TN cells in the contaminated group had faster migration rate, lower mRNA and protein expression levels of E-Cadherin, and higher mRNA and protein expression levels of α-SMA, CTGF, PI3K and Akt, with statistical significance ( P<0.05). After specific inhibition of CTGF expression, the mRNA and protein expression of CTGF, PI3K, Akt, and α-SMA in the cells of the interference group were significantly lower than that of the PQ group and the null-loaded group ( P<0.05/6), whereas that of E-Cadherin was higher than that of the PQ group and the null-loaded group ( P<0.05/6). Specifically blocking the PI3K/Akt signaling pathway, the mRNA and protein expression of PI3K, Akt and α-SMA in the cells of the inhibitor group was decreased compared with that of the PQ group ( P<0.05/3), while the expression of E-Cadherin was elevated compared with that of the PQ group ( P<0.05/3) . Conclusion:CTGF may promote PQ-induced alveolar epithelial cell EMT through activation of the PI3K/Akt signaling pathway. Inhibition of CTGF expression or blockade of PI3K/Akt signaling pathway activity can alleviate the extent of PQ-induced alveolar epithelial cell EMT.

Objective:To investigate the role of connective tissue growth factor (CTGF) and PI3K/Akt signaling pathways in paraquat (PQ) -induced alterations in alveolar epithelial cell mesenchymalization (EMT) .Methods:In February 2023, RLE-6TN cells were divided into 2 groups, which were set as uncontaminated group and contaminated group (200 μmol/L PQ), and cellular EMT alteration, CTGF and PI3K/Akt signaling pathway related molecules expression were detected by cell scratch assay, qRT-PCR and western-blot assay. Using shRNA interference technology to specifically inhibit the expression of CTGF, RLE-6TN cells were divided into four groups: control group, PQ group (200 μmol/L PQ), interference group (transfected with a plasmid with shRNA-CTGF+200 μmol/L PQ), and null-loaded group (transfected with a plasmid with scramble- CTGF+200 μmol/L PQ), qRT-PCR and western blot were used to examine the alteration of the cellular EMT and the expression of molecules related to the activity of PI3K/Akt pathway. The PI3K/Akt signaling pathway was blocked by the PI3K inhibitor LY294002, and the expression of EMT-related molecules in cells of the control group, PQ group (200 μmol/L PQ), and inhibitor group (200 μmol/L PQ+20 μmol/L LY294002) was examined by qRT-PCR and western blot.The t-test was used to compare the differences between the two groups, while the analysis of variance (ANOVA) was applied to compare the differences among multiple groups. For further pairwise comparisons, the Bonferroni method was adopted.Results:The results of cell scratch test showed that compared with the uncontaminated group, RLE-6TN cells in the contaminated group had faster migration rate, lower mRNA and protein expression levels of E-Cadherin, and higher mRNA and protein expression levels of α-SMA, CTGF, PI3K and Akt, with statistical significance ( P<0.05). After specific inhibition of CTGF expression, the mRNA and protein expression of CTGF, PI3K, Akt, and α-SMA in the cells of the interference group were significantly lower than that of the PQ group and the null-loaded group ( P<0.05/6), whereas that of E-Cadherin was higher than that of the PQ group and the null-loaded group ( P<0.05/6). Specifically blocking the PI3K/Akt signaling pathway, the mRNA and protein expression of PI3K, Akt and α-SMA in the cells of the inhibitor group was decreased compared with that of the PQ group ( P<0.05/3), while the expression of E-Cadherin was elevated compared with that of the PQ group ( P<0.05/3) . Conclusion:CTGF may promote PQ-induced alveolar epithelial cell EMT through activation of the PI3K/Akt signaling pathway. Inhibition of CTGF expression or blockade of PI3K/Akt signaling pathway activity can alleviate the extent of PQ-induced alveolar epithelial cell EMT.

As a first-line classical drug, glucocorticoids are used in most combination treatment regimens of keloid. However, there are issues such as poor treatment efficacy and recurrence of keloid after keloid was treated with glucocorticoids, which seriously affect the therapeutic effect. In recent years, many studies have explored the factors influencing the efficacy of glucocorticoids in treating keloid and the action mechanism of glucocorticoids from different perspectives. Based on this, this paper reviews the mechanism and the factors influencing the efficacy of glucocorticoids in treating keloid, and explores ways to improve the treatment efficacy of glucocorticoids, aiming to provide thoughts for improving glucocorticoid-related diagnostic and therapeutic strategies.

Objective To investigate the combined effect of noise and hand-transmitted vibration on hearing loss in male noise-exposed workers. Methods A total of 952 male noise-exposed workers from an automobile manufacturing enterprise were selected as the research subjects using judgment sampling method. Occupational epidemiological surveys, assessments of occupational hazards in workplace, and pure-tone audiometry tests were conducted on the research subjects, and they were divided into low-level noise group, low-level combined group, high-level noise group, and high-level combined group according to whether the noise exposure level exceeded the national standard and whether they were jointly exposed to hand-transmitted vibration. The joint effects of noise and hand-transmitted vibration on hearing loss were analyzed. Results The detection rate of hearing loss in 952 noise-exposed workers was 21.7%. The detection rate of hearing loss of four groups, from high to low, was as follows： high-level combined group, high-level noise group, low-level combined group, and low-level noise group (44.9% vs 32.7% vs 12.9% vs 5.7%, P<0.01). The results of multivariate logistic regression analysis showed that the risk of hearing loss in the low-level noise group, the low-level combined group, the high-level noise group and the high-level combined group increased sequentially after adjusting for the confounding factors such as age, education level, smoking, drinking, listening to music with headphones, frequency of wearing noise-blocking earplugs and body mass index. The risk of hearing loss in the high-level noise group was 8.62 times more than that of the low-level noise group (P<0.01). The risk of hearing loss in the low-level noise combined group was 2.50 times more than that of the low-level noise group (P<0.01). The risks of hearing loss in the high-level combined group were 5.76 and 1.67 times more than that of the low-level combined group and the high-level noise group. Conclusion Combined exposure to noise and hand-transmitted vibration can increase the risk of hearing loss in male noise-exposed workers, and the higher the noise intensity, the greater the synergistic effect. Hand-transmitted vibration is a synergistic risk factor for occupational noise-induced hearing loss.

Objective:Analyze epidemiological situation of dengue fever,and survey impacts of four serotypes dengue viruses in Guangzhou, 2019.Methods:Information of patients was collected in Notifiable Infectious Disease Report System (NIDRS). Spatial autocorrelation of dengue cases was evaluated using ArcGIS version 10.2. Serum samples were tested by real-time PCR. Virus strains were isolated from positive sera. Then E gene was sequenced. Phylogenetic trees were including PhyMLsoftwarev 3.1.Results:A total of 1 655 dengue cases, consisted of 1 382 local cases and 273 imported cases, was confirmed in 2019. The incidence was 11.10 per 100 000 dengue cases were autocorrelated in Guangzhou. There were 18 high-high clusters. Most of the imported dengue cases were imported from Southeast Asian countries (86.08%,235/273) and African countries (2.56%,7/273). Of 749 serum samples detected by real-time PCR, the positive rate was 93.06% (697/749). Four hundred and sixty-four dengue virus strains had been isolated in 2019. Compared with data from the genotype tree of the former years, no genotype shift was discovered. Serotype 1 was still predominant. Serotype 2 was the significant strain in Baiyun district and Liwan district.Conclusions:Dengue fever was spreading all over Guangzhou in 2019. The suburban areas, which played a more critical role in causing the spread and outbreak of dengue fever, should be given more prominence. Inspection at ports should be enforced to prevent importing cases from African countries and Southeast Asian countries. The risk of serotype 2 cannot be overlooked. Four serotypes dengue viruses prevailed simultaneously in Guangzhou, which warns us to take precaution of severe dengue outbreaks.

Objective:To study the changes of proliferation and oxidation indexes of Cochlear hair cell line (HEI-OC1 cells) exposed to ethylbenzene.Methods:From July to December 2019, 11 groups with ethylbenzene concentrations of 0, 30, 60, 90, 300, 600, 900 μmol/L and 3, 6, 9, 10 mmol/L, were used to determine the proliferation activity of HEI-OC1 cells exposed to ethylbenzene for 24 hours, and the cells were treated with 0, 1, 2, 4, 8, 16, 32, 64 mmol/L ethylbenzene for 24 hours, then the 50% inhibitory concentration of ethylbenzene was calculated. After HEI-OC1 cells were exposed to 0, 6, 9 and 12 mmol/L ethylbenzene for 24 hours, the malondialdehyde (MDA) content, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were measured.Results:Compared with 0 mmol/L concentration group, the survival rate of HEI-OC1 cells at 6, 9, 12 mmol/L concentration was significantly decreased ( P<0.01) . The 50% inhibitory concentration of ethylbenzene on HEI-OC1 cells was 12.86 mmol/L ( R2=99.05) . There were significant differences in SOD and GSH-Px activity in HEI-OC1 cells treated with ethylbenzene at different concentrations (0, 6, 9, 12 mmol/L) for 24 hours ( F=65.11, 6.48, 22.85, P<0.05) . Compared with 0 mmol/L concentration group, the MDA content of HEI-OC1 cells was significantly increased in 9 and 12 mmol/L concentration groups, the SOD activity was significantly decreased in 12 mmol/L concentration group, and the GSH-Px activity was significantly decreased in 6 and 12 mmol/L concentration groups. Conclusion:Ethylbenzene can inhibit the proliferation of HEI-OC1 cells and cause oxidative damage.

Objective:To discuss the effect of low-dose ionizing radiation on the health of radiation workers, and provide a basis for occupational health risk assessment of radiation workers.Methods:In January 2020, 3165 radiation workers who performed radiation occupational health examinations in Guangzhou Prevention and Treatment Hospital for Occupational Disease from January 2017 to December 2019 were selected as the research objects, and compared and analyzed the health status of radiation workers with different examination types (pre-job, in-job and off-job) , types of work, gender, and length of service.Results:The off-job occupational radiological health examination was rare at 2.3% (74/3165) . The abnormal detection rate of chest radiographs, renal function, thyroid function, and blood routine of the radiation workers in-job group was higher than that of the pre-job group ( P<0.05) . No statistical difference was found in the abnormal detection rate of the examination items during the in-job group and the off-job group ( P>0.05) . The blood routine abnormality detection rate of medical application group and industrial application group were higher than those of nuclear fuel group ( P<0.05) . The abnormal detection rate of blood pressure and renal function of male radiation workers was higher than that of females, while the abnormal detection rate of blood routine of females was higher than that of males ( P<0.05) . The abnormal detection rate of electrocardiogram, chest radiograph, blood pressure, renal function, thyroid function, and blood routine of radiation workers increased with increasing working age ( P<0.05) . Conclusion:Occupational health status of radiation workers is not optimistic. Radiation occupational health monitoring should be strengthened, special attention should be paid to off-job radiation occupational health examination, focusing on the sensitive indicators of sensitive personnel, improving radiation protection conditions, and effectively protecting the occupational health of radiation workers.

Objective:To investigate the occurrence of work-related musculoskeletal disorders (WMSDs) in the cabinet factory workers, and explore the influencing factors of workers' WMSDs.Methods:A cross-sectional survey method was used to investigate the risk factors such as basic conditions, labox dnganiza, ergonomics load and occurrence of WMSDs of 821 workers in a cabinet factory of a furniture manufacturing company in Guangdong Province using the electronic version of the Musculoskeletal Injury Questionnaire from October to December 2019. χ 2 test and logistic regression were used to analyze the risk factors leading to WMSDs. Results:The incidence of WMSDs in cabinet production workers reached 51.5% (423/821) , and the top three incidences were shoulder (28.4%, 233/821) , neck (28.1%, 231/821) , and wrist (25.9%, 213/821) . The incidence of neck WMSDs was statistically significant among different types of work ( P<0.05) . Multiple repetitive operations per minute ( OR=1.70) , torso often maintaining the same posture ( OR=1.61) , turning heads for a long time ( OR=1.58) and frequent heavy lifting ( OR=1.44) were risk factors for the occurrence of shoulder WMSDs ( P<0.05) . Frequent maintenance of the same posture in the neck ( OR=1.91) , repeated operations per minute ( OR=1.87) , shortage of department staff ( OR=1.65) and turning head for a long time ( OR=1.48) were risk factors for the occurrence of neck WMSDs ( P<0.05) . Long-term bending of the wrist ( OR=2.25) , grasping objects tightly ( OR=2.13) , working hard on the upper limbs or hands ( OR=1.91) , shortage of department personnel ( OR=1.84) , repeated operations per minute ( OR=1.68) and the use of vibration tools ( OR=1.51) were risk factors for the occurrence of WMSDs in the wrist ( P<0.05) . Conclusion:The incidence of WMSDs in cabinet factory is relatively high, the occurrence of WMSDs in the shoulders, necks and wrists is more serious. Reasonable labor organization and reducing the load of poor ergonomics in the workplace, can reduce the occurrence of WMSDs in production workers.

Objective:To study the changes of proliferation and oxidation indexes of Cochlear hair cell line (HEI-OC1 cells) exposed to ethylbenzene.Methods:From July to December 2019, 11 groups with ethylbenzene concentrations of 0, 30, 60, 90, 300, 600, 900 μmol/L and 3, 6, 9, 10 mmol/L, were used to determine the proliferation activity of HEI-OC1 cells exposed to ethylbenzene for 24 hours, and the cells were treated with 0, 1, 2, 4, 8, 16, 32, 64 mmol/L ethylbenzene for 24 hours, then the 50% inhibitory concentration of ethylbenzene was calculated. After HEI-OC1 cells were exposed to 0, 6, 9 and 12 mmol/L ethylbenzene for 24 hours, the malondialdehyde (MDA) content, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were measured.Results:Compared with 0 mmol/L concentration group, the survival rate of HEI-OC1 cells at 6, 9, 12 mmol/L concentration was significantly decreased ( P<0.01) . The 50% inhibitory concentration of ethylbenzene on HEI-OC1 cells was 12.86 mmol/L ( R2=99.05) . There were significant differences in SOD and GSH-Px activity in HEI-OC1 cells treated with ethylbenzene at different concentrations (0, 6, 9, 12 mmol/L) for 24 hours ( F=65.11, 6.48, 22.85, P<0.05) . Compared with 0 mmol/L concentration group, the MDA content of HEI-OC1 cells was significantly increased in 9 and 12 mmol/L concentration groups, the SOD activity was significantly decreased in 12 mmol/L concentration group, and the GSH-Px activity was significantly decreased in 6 and 12 mmol/L concentration groups. Conclusion:Ethylbenzene can inhibit the proliferation of HEI-OC1 cells and cause oxidative damage.

Objective:To discuss the effect of low-dose ionizing radiation on the health of radiation workers, and provide a basis for occupational health risk assessment of radiation workers.Methods:In January 2020, 3165 radiation workers who performed radiation occupational health examinations in Guangzhou Prevention and Treatment Hospital for Occupational Disease from January 2017 to December 2019 were selected as the research objects, and compared and analyzed the health status of radiation workers with different examination types (pre-job, in-job and off-job) , types of work, gender, and length of service.Results:The off-job occupational radiological health examination was rare at 2.3% (74/3165) . The abnormal detection rate of chest radiographs, renal function, thyroid function, and blood routine of the radiation workers in-job group was higher than that of the pre-job group ( P<0.05) . No statistical difference was found in the abnormal detection rate of the examination items during the in-job group and the off-job group ( P>0.05) . The blood routine abnormality detection rate of medical application group and industrial application group were higher than those of nuclear fuel group ( P<0.05) . The abnormal detection rate of blood pressure and renal function of male radiation workers was higher than that of females, while the abnormal detection rate of blood routine of females was higher than that of males ( P<0.05) . The abnormal detection rate of electrocardiogram, chest radiograph, blood pressure, renal function, thyroid function, and blood routine of radiation workers increased with increasing working age ( P<0.05) . Conclusion:Occupational health status of radiation workers is not optimistic. Radiation occupational health monitoring should be strengthened, special attention should be paid to off-job radiation occupational health examination, focusing on the sensitive indicators of sensitive personnel, improving radiation protection conditions, and effectively protecting the occupational health of radiation workers.