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Background The current increasing trend of new cases of occupational noise-induced deafness indicates that the hearing loss of occupational population has not been effectively controlled in China. It is of great significance to study the characteristics of hearing loss among noise-exposed workers and its related factors. Objective To investigate characteristics and influencing factors of hearing loss among occupational noise-exposed workers in a large machinery maintenance enterprise, and to provide a scientific basis to prevent and control noise-induced hearing loss. Methods A cross-sectional survey was conducted to investigate male Han occupational noise-exposed workers in a large mechanical maintenance enterprise. We acquired demographic characteristics, occupational exposure history, and individual life behavior characteristics of the workers through questionnaires, collected occupational exposure level data from annual occupational disease hazard factor surveillance reports, obtained pure tone hearing threshold test data through occupational health examinations, and estimated individual noise exposure levels using cumulative noise exposure (CNE). According to the results of pure tone air conduction hearing threshold test, the workers were divided into a hearing loss group and a normal hearing group. The chi-square test was employed to compare the occupational exposure characteristics and individual life behavior characteristics between the two groups. Additionally, the trend chi-square test was utilized to analyze the changing trends of age, length of service, CNE, and hearing loss rate within the two groups. The relationship between high-frequency hearing loss in both ears and its related influencing factors was assessed by a multiple logistic regression model. Results The M (P25, P75) of CNE for the 2531 occupational noise-exposed workers was 97.51 (95.39, 99.96) dB(A)·year. The incidence of hearing anomaly, binaural high-frequency hearing anomaly, random ear high-frequency hearing anomaly, binaural low-frequency hearing anomaly, and random ear low-frequency hearing anomaly were 22.48%, 16.59%, 22.13%, 2.77%, and 3.52%, respectively. High-frequency hearing threshold increase was the main reason for hearing anomaly (98.42%). In comparison to the CNE ≤ 97 dB(A)·year group, the 97 dB(A)·year<CNE≤ 100 dB(A)·year group and the CNE>100 dB(A)·year group experienced a 36.4% and 52.3% increase in the risk of bilateral high-frequency hearing loss, respectively. The smoking group exhibited a 43.5% elevated risk of bilateral high-frequency hearing loss when compared to the non-smoking group. Conversely, the group frequently wearing hearing protection equipment demonstrated a 23.6% lower risk of bilateral high-frequency hearing loss in comparison to the group occasionally wearing protective equipment. The data suggested that CNE＞97 dB(A)·year and smoking might be independent risk factors for bilateral high-frequency hearing loss, and frequently wearing hearing protection equipment might be an important protective factor. Conclusion Increased CNE and smoking can elevate the risk of high-frequency hearing loss, while personal hearing protection can effectively reduce the risk of hearing loss.
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Objective@#To study the adaptive response and time effect of A549 cell apoptosis induced by low-dose X-ray irradiation, and to preliminarily explore the possible mechanism of adaptive effect. @*Methods@#A549 cells were irradiated with X-ray of 50 mGy, 200 mGy and 500 mGy, respectively, and then irradiated with an effect dose of 20 Gy after intervals of 3 h, 6 h, 12 h, 24 h and 48 h, respectively, for cell apoptosis detection. The cell cycle distribution and DNA damage were detected after an interval of 6 h between the initial dose and the effect dose. 20 Gy and 0 Gy were set as the control.@*Results@#After irradiation at 20 Gy at intervals of 3 h, 6 h, 12 h and 24 h from the low- dose irradiation, the apoptosis rates of the 50 mGy～20 Gy, 200 mGy～20 Gy, and 500 mGy~ 20 Gy groups were significantly lower than that of the 20 Gy group (P < 0.05); after an interval of 48 h, there was no significant difference in the apoptosis rate between the 50 mGy～20 Gy, 200 mGy～20 Gy, and 500 mGy～20 Gy groups and the 20 Gy group. After an interval of 6 h between the low-dose irradiation and the effect dose irradiation, the percentage of cells at G0/G1 phase in the 50 mGy～20 Gy and 200 mGy～20 Gy groups was significantly lower than that in the 20 Gy group (P < 0.05); the percentage of cells at G2/M phase in the 50 mGy～20 Gy and 200 mGy~20 Gy groups were significantly reduced compared with the 20 Gy group (P < 0.05). There was no significant difference in the percentage of cells at G0/G1 and G2/M phases between the 500 mGy～20 Gy and 20 Gy groups. Compared with the 20 Gy group, the cell DNA damage in the 50 mGy～20 Gy, 200 mGy～20 Gy and 500 mGy~20 Gy groups were decreased, but without significant difference. @*Conclusion@#Low-dose X-ray irradiation can induce the adaptive response of A549 cells apoptosis, which is related to the time interval between the initial dose and the effect dose. The adaptive effect may be related to the changes in cell cycle induced by low-dose X-ray.
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Background Gene sequencing industry is an emerging innovation-driven industry. Employees have high requirements for independent learning and innovation ability and face great professional pressure. Objective To understand the occupational stress, depression, and sleep of gene sequencing enterprise employees and to analyze the effect of occupational stress on depression and sleep. Methods From November to December 2021, occupational stress, depression, and sleep conditions of 469 workers from 34 enterprises in gene sequencing industry were surveyed by Core Occupational Stress Scale (COSS), Patient Health Questionnaire 9 (PHQ-9), and Pittsburgh Sleep Quality Index (PSQI). A total of 427 valid questionnaires were recovered with a questionnaire valid response rate of 91.04%. The relationship of occupational stress with depression or sleep was analyzed by logistic regression. Results The rates of occupational stress, depression, and sleep disorder were 27.40%, 33.50%, and 28.10%, respectively. Significant difference were found in the rates of depression and sleep disorder in different occupational stress groups (P<0.05). The results of logistic regression analysis showed that, for every 1 increase in social support score, the risk of depression increased by 1.206 (95%CI: 1.117−1.304), and the risk of sleep disorder increased by 1.143 (95%CI: 1.059−1.233). For every 1 increase in organization and reward score, the risk of developing depression increased by 1.082 (95%CI: 1.017−1.151). Mild, moderate, and severe occupational stress were all associated with a higher risk of depression in reference to no occupational stress (OR=2.535, 95%CI: 1.465−4.386; OR=3.774, 95%CI: 1.809−7.870; OR=3.823, 95%CI: 1.486−9.837). Severe occupational stress was associated with a higher risk of sleep disorder in reference to no occupational stress (OR=3.141, 95%CI: 1.233−8.006). Conclusion Occupational stress among employees in the gene sequencing industry can increase the risks of depression and sleep disorder. Enterprises need to take intervention measures and pay attention to prevention and treatment.
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Objective@#To develop a method using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry to determine the urinary metabolites of benzene, toluene and xylene. The selected metabolites are S-phenylmercapturic acid (S-PMA) , trans, trans-muconic acid (t, t-MA) , 8-hydroxy-2 deoxyguanosine (8-OHdG) , hippuric acid (HA) , 2-methylhippuric acid (2-MHA) , 3-methylhippuric acid (3-MHA) and 4-methylhippuric acid (4-MHA) .@*Methods@#The urine sample was pretreated using methanol to precipitate the proteins. HSS T3 chromatographic column was used to separate the metabolites. The mass spectrometric acquisition was carried out using multiple reaction monitoring (MRM) after ionization with ESI source. External standard method was used for quantification.@*Results@#All the standard curves showed good linear relation, and r of the seven metabolites was all above 0.999. The detection limits and quantitative limits of the seven metabolites were 0.01-500 ng/ml and 0.02-1 000 ng/ml (based on the actual dilution ratio) , respectively. The average spiked recoveries of four loadings ranged from 85.8% to 109.9%. The intra-day and inter-day precisions were 0.2%-4.5% and 0.6%-9.5%, respectively. The samples can be kept for at least 14 days at both 4 ℃ and -20 ℃.@*Conclusion@#This method is simple, rapid and highly sensitive with low cost, and its accuracy, precision and stability can meet the daily test requirements. It can be applied for the determination of urinary S-PMA, t, t-MA, 8-OHdG, HA, 2-MHA, 3-MHA and 4-MHA for the occupational population exposed to benzene, toluene and xylene.
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Objective@#To establish a liquid chromatography tandem mass spectrometry method to determine the cortisol in saliva.@*Methods@#Take 0.5 ml saliva sample into a 2 ml centrifuge tube, add excess sodium chloride and 1ml acetonitrile to it, then vortex for 3 min, centrifuge for 10 min at 15 000 r/min, and take 800 μl of the upper layer to another centrifuge tube. Finally, the sample was concentrated by a vacuum concentrator and brought to 200 μl with the initial mobile phase. Then, the sample was analyzed by liquid chromatography tandem mass spectrometry. The target compound was quantified by external standard curve method.@*Results@#The linear range of the method was 0.02-5.00 ng/ml, r=0.999 9, the method limit of the detection was 0.002 ng/ml, the method limit of quantitative was 0.02 ng/ml, and the spiked recoveries were 89.60%-98.60%. The intra-assay precision was 1.90%-3.30%, and the inter-assay precision was 4.20%-9.00%; samples could be stored at -20 °C for at least 14 days. The determination of cortisol could not be interfered by other endogenous substances in the sample.@*Conclusion@#The method is simple in pretreatment, high sensitivity, good reproducibility and good recovery, and it is suitable for the quantitative analysis of cortisol in saliva for normal and occupationally stressed populations.
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Objective To preliminarly investigate the application value of Pipeline embolization device ( PED ) in the endovascular interventional treatment of complex intracranial aneurysms. Methods From July 2015 to October 2016, the clinical data of 10 consecutive patients with complex intracranial aneurysm treated with PED at the Department of Neurosurgery, Guangdong General Hospital were enrolled retrospectively. Their surgical modalities,complications,and imaging findings were analyzed. Results Of the 10 patients,7 were females and 3 were males,their age was 32-68 years ( mean age 54 ± 12 years) . There were 8 patients with internal carotid artery aneurysm,1 with middle cerebral artery aneurysm,and 1 with vertebrobasilar artery aneurysm;there were 2 patients with ruptured aneurysm and 8 with unruptured aneurysm;there were 5 patients with saccular aneurysm ( 2 with wide-necked aneu-rysm) ,3 with fusiform aneurysm,2 with dissecting aneurysm;there were 2 patients with medium aneurysm ( diameter>5-15 mm) ,2 with large aneurysm ( diameter>15-25 mm) ,6 with giant aneurysm ( diameter>25 mm) ,and there were 2 patients with recurrent aneurysm. They were all single aneurysms. Three patients were treated with PED in combination with coil embolization,and 7 patients were treated with PED implantation alone. Nine patients were treated with one PED and 1 was treated with 3 PEDs. The immediate postoperative angiography revealed that the contrast agents in the aneurysm cavities were obviously stranded. One patient died after procedure and 1 had quadriplegia after procedure,and the remaining 8 patients had no PED-related complications. The modified Rankin scale score was 0 in 8 cases,5 in 1 case,and 6 in 1 case on the first post-operative day. They were followed up for 14 to 28 months. Conclusions The different types of intracranial aneurysms treated with PED implantation is relatively safe and effective,but there are also some risks of dis-ability and death. Strictly selecting the indications and developing the individualized treatment strategies are needed.
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The development of optimal strategies for breast cancer prevention is necessary given the high incidence in China. Several prospective randomized clinical trials have investigated the effects of various pharmacologic agents on the incidence of invasive and noninvasive breast cancer. This review aimed to summarize the different approaches to reduce the incidence of breast cancer.
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Objective To explore effects of paclitaxel on proliferation and migration of breast cancer Michigan Cancer Foundation-7 (MCF-7) cells via mammalian target of rapamycin (mTOR) signaling pathway.Methods The cases were randomly divided into four groups,including control group,paclitaxel low-dose group (0.25 μmol/L),paclitaxel medium-dose group (0.5 μmol/L),and paclitaxel high-dose group (1 μmol/L).The viability of MCF-7 cells was measured with methyl thiazolyl tetrazolium (MTT) assay.MCF-7 cell cycle was examined with flow cytometry.MCF-7 cell migration was tested with transwell migration assay.The levels of mTOR signalling pathway-related protein were assayed with Western blot.Results Compared to the control group,MCF-7 cell viability was significantly decreased in paclitaxel low,medium and high-dose groups (P ＜ 0.05),and the inhibitory rate was highest at 48 h (P ＜ 0.05).MCF-7 cell migration was significantly inhibited in paclitaxel low,medium and high-dose groups [(98 ± 9.78) vs (86.21 ± 6.58),(53.41 ± 3.16) and (42.00 ± 4.69),P ＜ 0.05].Moreover,compared to the control group,the number of MCF-7 cells at G1 phase was significantly increased in paclitaxel low,medium and high-dose groups [(52.14±6.13)％ vs (67.93 ±8.16)％,(72.32 ±3.67)％ and (78.53 ± 6.28)％,P ＜ 0.01],the number of MCF-7 cells at G2 phase was significantly reduced in paclitaxel low,medium and high-dose group [(13.68 ± 0.85) ％ vs (8.57 ± 1.03) ％,(5.30 ± 0.89) ％ and (3.46 ± 0.78) ％,P ＜0.01].The phosphorylations of 4E binding protein (4EBP1) and mTOR proteins as well as the expressions of cell-cycle protein D1 (Cyclin D1) and matrix metalloproteinase-9 (MMP-9) were significantly inhibited in paclitaxel low,medium and high-dose groups (P ＜ 0.01).Conclusions These results suggested paclitaxel could inhibit proliferation and migration in breast cancer MCF-7 cells,which might be related to mTOR signal pathway.
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The axillary reverse mapping (ARM) is a new minimally invasive technique, which has been developed to map and preserve arm lymphatic drainage during axillary lymph node dissection (ALND)and/or sentinel lymph node (SLN) biopsy, thereby minimizing arm lymphedema.
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AIM: To study the effect and mechanism of chlorophyllin (CHL) inhibiting HT29 cells. METHODS: IC 50 value and growth curve of HT29 cells were detected with MTT method. Apoptosis was detected with Wright-Giemsa staining, FCM and DNA electrophoresis. Telomerase was detected by PCR-ELISA, and protein and mRNA expression of COX-2 gene were detected through RT-PCR and Western blot. RESULTS: CHL inhibited the growth of HT29 in a dose-dependent manner. CHL blocked HT29 cells in G 1 phase but did not induce apoptosis. Different concentration of CHL inhibits the expression of telomerase and COX-2 in HT29 cells. CONCLUSION: CHL inhibits the growth of HT29 cells by inhibiting the expression of telomerase and COX-2 and blocking cells in G 1 phase. [