Objective To explore the mechanism through which dexmedetomidine(Dex)alleviates doxorubicin(Adr)-induced myo-cardial injury via regulating nuclear factor κB(NF-κB)expression.Methods Sprague-Dawley rats were divided into control,Adr,and Adr+Dex groups.Theirs hearts were harvested for hematoxylin and eosin(HE)staining,immunohistochemical staining,real-time polymerase chain reaction(PCR),and Western blotting anlyses.The rat primary cardiomyocytes,breast cancer cell line MDA-MB-23,lung cancer cell line H226,gastric cancer cell line AGS,and bladder cancer cell line 5637 were cultured and divided into control,Adr,Adr+Dex,Dex,and Adr+Dex+NF-κBi groups.CCK-8 and immunofluorescence staining were performed to detect the reactive oxygen species(ROS)contents.Results The myocardial arrangement of the rats in the Adr group was disordered,myocardial cell activity was lower,the mitochondrial membrane potential was lower,ROS production was higher,and NF-κB mRNA and protein contents were sub-stantially lower than those in the control group.The cardiomyocyte morphology was improved,cell activity was higher,mitochondrial mem-brane potential was increased,ROS production decreased,and NF-κB expression significantly increased in the Adr+Dex group compared with those in the control group.The mitochondrial membrane potential in the Adr+Dex+NF-κBi group was lower,and ROS generation was increased compared with the control group.The activity of the tumor cells in the Adr group was lower,and no statistically significant diffe-rences were found compared with that in the Adr+Dex group.Conclusion Treatment with Dex may not affect the chemotherapeutic effects of Adr.Dex administration may increase the myocardial mitochondrial membrane potential and reduce ROS generation by regu-lating NF-κB levels,thereby reducing Adr-induced myocardial damage.

Objective To explore the mechanism through which dexmedetomidine(Dex)alleviates doxorubicin(Adr)-induced myo-cardial injury via regulating nuclear factor κB(NF-κB)expression.Methods Sprague-Dawley rats were divided into control,Adr,and Adr+Dex groups.Theirs hearts were harvested for hematoxylin and eosin(HE)staining,immunohistochemical staining,real-time polymerase chain reaction(PCR),and Western blotting anlyses.The rat primary cardiomyocytes,breast cancer cell line MDA-MB-23,lung cancer cell line H226,gastric cancer cell line AGS,and bladder cancer cell line 5637 were cultured and divided into control,Adr,Adr+Dex,Dex,and Adr+Dex+NF-κBi groups.CCK-8 and immunofluorescence staining were performed to detect the reactive oxygen species(ROS)contents.Results The myocardial arrangement of the rats in the Adr group was disordered,myocardial cell activity was lower,the mitochondrial membrane potential was lower,ROS production was higher,and NF-κB mRNA and protein contents were sub-stantially lower than those in the control group.The cardiomyocyte morphology was improved,cell activity was higher,mitochondrial mem-brane potential was increased,ROS production decreased,and NF-κB expression significantly increased in the Adr+Dex group compared with those in the control group.The mitochondrial membrane potential in the Adr+Dex+NF-κBi group was lower,and ROS generation was increased compared with the control group.The activity of the tumor cells in the Adr group was lower,and no statistically significant diffe-rences were found compared with that in the Adr+Dex group.Conclusion Treatment with Dex may not affect the chemotherapeutic effects of Adr.Dex administration may increase the myocardial mitochondrial membrane potential and reduce ROS generation by regu-lating NF-κB levels,thereby reducing Adr-induced myocardial damage.

Objective:To explore the relationship between the binaural high-frequency mean hearing threshold and the hypertension of female workers exposed to noise, and to understand the application significance of the binaural high-frequency mean hearing threshold as an internal effect indicator of the risk of hypertension in female workers exposed to noise.Methods:From January to December 2018, a total of 20882 female workers exposed to noise in Guangzhou were selected by cluster sampling. Pure tone audiometry, blood pressure, age and length of service were collected. Trend test was used to evaluate the effects of exposure to noise and binaural high-frequency mean hearing threshold on blood pressure. Binary logistic regression model was used to evaluate the risk of hypertension associated with exposure to noise and binaural high-frequency mean hearing threshold.Results:The detection rate of normal hearing threshold, mild hearing loss and severe hearing loss was 80.73% (16858/20882) , 16.21% (3384/20882) and 3.06% (640/20882) respectively. The prevalence of hypertension was 6.04% (1018/16858) in normal hearing group, 10.28% (348/3384) in patients with high frequency mild hearing loss, and 11.25% (72/640) in patients with high frequency severe hearing loss. There was a linear relationship between the increase of working age and high-frequency mean hearing threshold and the increase of systolic and diastolic blood pressure ( P< 0.05) . Compared with those exposed to noise for less than 1 year, the risk of hypertension in female workers with 7-9 years and more than 9 years was decreased ( OR= 0.79, 0.75, P<0.05) . Compared with normal hearing group, the risk of hypertension in high frequency mild hearing loss group was increased ( OR=1.31, P<0.05) . Conclusion:The increase in the binaural high-frequency mean hearing threshold of female workers exposed to noise can increase the blood pressure level and the risk of hypertension, and attention should be paid to female workers with high-frequency mild hearing loss.

Objective:To explore the relationship between the binaural high-frequency mean hearing threshold and the hypertension of female workers exposed to noise, and to understand the application significance of the binaural high-frequency mean hearing threshold as an internal effect indicator of the risk of hypertension in female workers exposed to noise.Methods:From January to December 2018, a total of 20882 female workers exposed to noise in Guangzhou were selected by cluster sampling. Pure tone audiometry, blood pressure, age and length of service were collected. Trend test was used to evaluate the effects of exposure to noise and binaural high-frequency mean hearing threshold on blood pressure. Binary logistic regression model was used to evaluate the risk of hypertension associated with exposure to noise and binaural high-frequency mean hearing threshold.Results:The detection rate of normal hearing threshold, mild hearing loss and severe hearing loss was 80.73% (16858/20882) , 16.21% (3384/20882) and 3.06% (640/20882) respectively. The prevalence of hypertension was 6.04% (1018/16858) in normal hearing group, 10.28% (348/3384) in patients with high frequency mild hearing loss, and 11.25% (72/640) in patients with high frequency severe hearing loss. There was a linear relationship between the increase of working age and high-frequency mean hearing threshold and the increase of systolic and diastolic blood pressure ( P< 0.05) . Compared with those exposed to noise for less than 1 year, the risk of hypertension in female workers with 7-9 years and more than 9 years was decreased ( OR= 0.79, 0.75, P<0.05) . Compared with normal hearing group, the risk of hypertension in high frequency mild hearing loss group was increased ( OR=1.31, P<0.05) . Conclusion:The increase in the binaural high-frequency mean hearing threshold of female workers exposed to noise can increase the blood pressure level and the risk of hypertension, and attention should be paid to female workers with high-frequency mild hearing loss.

Objective:To investigate the epidemiological characteristics and late diagnosis of suspected occupational diseases in Guangzhou from 2006 to 2018.Methods:The cases of suspected occupational diseases reported in Guangzhou from January 1, 2006 to December 31, 2018 were collected and followed up to the end of 2018. The cases of suspected occupational diseases were analyzed statistically.Results:A total of 1502 suspected occupational cases were reported in Guangzhou from 2006 to 2018, including suspected occupational otorhinolaryngological and oral diseases (58.59%, 880/1502) , suspected occupational chronic poisoning (25.03%, 376/1502) and suspected occupational pneumoconiosis (11.72%, 176/1502) . The key reporting areas were Huangpu District (27.50%, 413/1502) and Panyu District (20.91%, 314/1502) . The key reporting industries were manufacturing industry (80.36%, 1207/1502) , among which railway, ship, aerospace and other transportation equipment manufacturing industry (13.26%, 160/1207) , automobile manufacturing industry (12.51%, 151/1207) and general equipment manufacturing industry (10.19%, 123/1207) were the main industries. The main type of reported economy was private economy (39.95%, 600/1502) . The scale of the key reporting enterprises was medium and small-sized enterprises (31.09%, 467/1502 and 34.62%, 520/1502) . As of December 31, 2018, 263 cases were diagnosed with occupational diseases, and the diagnosis rate was 17.51%.Conclusion:The number of suspected occupational diseases reported in Guangzhou from 2006 to 2018 is large, and the overall diagnosis rate of suspected occupational diseases is low. It is necessary to strengthen the supervision and management of key diseases, key regions, and key industries of suspected occupational diseases. It is suggested that the reporting system of suspected occupational diseases should be standardized as soon as possible.

Objective:To investigate the epidemiological characteristics and late diagnosis of suspected occupational diseases in Guangzhou from 2006 to 2018.Methods:The cases of suspected occupational diseases reported in Guangzhou from January 1, 2006 to December 31, 2018 were collected and followed up to the end of 2018. The cases of suspected occupational diseases were analyzed statistically.Results:A total of 1502 suspected occupational cases were reported in Guangzhou from 2006 to 2018, including suspected occupational otorhinolaryngological and oral diseases (58.59%, 880/1502) , suspected occupational chronic poisoning (25.03%, 376/1502) and suspected occupational pneumoconiosis (11.72%, 176/1502) . The key reporting areas were Huangpu District (27.50%, 413/1502) and Panyu District (20.91%, 314/1502) . The key reporting industries were manufacturing industry (80.36%, 1207/1502) , among which railway, ship, aerospace and other transportation equipment manufacturing industry (13.26%, 160/1207) , automobile manufacturing industry (12.51%, 151/1207) and general equipment manufacturing industry (10.19%, 123/1207) were the main industries. The main type of reported economy was private economy (39.95%, 600/1502) . The scale of the key reporting enterprises was medium and small-sized enterprises (31.09%, 467/1502 and 34.62%, 520/1502) . As of December 31, 2018, 263 cases were diagnosed with occupational diseases, and the diagnosis rate was 17.51%.Conclusion:The number of suspected occupational diseases reported in Guangzhou from 2006 to 2018 is large, and the overall diagnosis rate of suspected occupational diseases is low. It is necessary to strengthen the supervision and management of key diseases, key regions, and key industries of suspected occupational diseases. It is suggested that the reporting system of suspected occupational diseases should be standardized as soon as possible.