[Analysis of influencing factors of high-frequency hearing loss among male noise workers in an automobile manufacturing enterprise].

Objective: To analysis of high-frequency hearing loss status and risk factors among male noise workers in an automobile manufacturing enterprise in Guangzhou. Methods: From February 2020, a cluster sampling method was used to select 3486 male workers exposed to noise in an automobile manufacturing enterprise in Guangzhou in 2018. After screening, 2608 were selected as the research objects. Pure tone hearing threshold test, noise exposure level test and questionnaire survey were conducted, and the cumulative noise exposure was calculated. Chi square test and unconditional logistic regression were used to analyze the correlation between various factors and high frequency hearing loss. Results: The detection rate of high-frequency hearing loss in noise exposed workers was 34.20% (892/2608) , there were significant differences in the two groups among age, marital status, years of noise exposure, noise exposure equivalent A sound level, CNE, different working hours and exposure to electromagnetic radiation (P<0.05) . Multiple logistic regression analysis showed that age, CNE and exposure to electromagnetic radiation were independent risk factors for high-frequency hearing loss (P<0.05) , three shifts and two shifts were the protective factors for the occurrence of high-frequency hearing loss (OR=0.523, P<0.01) . Conclusion: Noise exposure is the main influencing factor of high-frequency hearing loss of noise-receiving workers in automobile manufacturing enterprises. Enterprises should strengthen noise control in the workplace, improve the working environment of electromagnetic radiation, and implement a scientific and healthy work shift system.

[Combined effect of noise and hand-transmitted vibration on noise-induced hearing loss in the automobile manufacturing industry].

Objective: To investigate the combined effect of noise and hand-transmitted vibration on noise-induced hearing loss (NIHL) in the automobile manufacturing industry. Methods: From September 2018 to January 2019, cluster sampling was used to select 998 workers in an automobile factory as study subjects, among whom 352 workers exposed to noise alone were enrolled as noise group, 342 workers exposed to noise and hand-transmitted vibration were enrolled as combined effect group, and 304 workers without exposure to occupational hazardous factors were enrolled as control group. A questionnaire survey and pure tone audiometry were performed for all study subjects. An analysis of variance was used for comparison of continuous data between groups, and the chi-square test was used for comparison of categorical data between groups; a ordinal polytomous logistic regression analysis was used to investigate the influencing factors for NIHL (with 0.05 as the inclusion criteria and 0.10 as the exclusion criteria for independent variables) . Results: There was a significant difference in L(Aeq, 8 h) between groups (P<0.05) ; the noise group and the combined effect group had a significantly higher L(Aeq, 8 h) than the control group (P<0.05) , while there was no significant difference in L(Aeq, 8 h) between the noise group and the combined effect group (P>0.05) . The control group had a significantly lower detection rate of hearing loss than the noise group and the combined effect group (P<0.0125) , and the combined effect group had a significantly higher detection rate of hearing loss than the noise group (P<0.0125) . The ordinal polytomous logistic regression analysis showed that after adjustment for confounding factors such as age, working years, sex, smoking, and drinking, both noise exposure and exposure to both noise and hand-transmitted vibration had an influence on workers' hearing (P<0.05) , and the workers exposed to both noise and hand-transmitted vibration had a higher risk of hearing loss than those exposed to noise alone. Conclusion: There may be a combined effect of noise and hand-transmitted vibration in the automobile manufacturing industry, which can increase the risk of NIHL in workers.

[Prevalence of breast and gynecological diseases in female workers in the administrative office and workshop of an automobile part factory].

Objective: To investigate the prevalence of breast and gynecological diseases in female workers in the administrative office and workshop of an automobile part factory, and to provide a basis for promoting the health of female workers. Methods: In March 2015, color ultrasound examination of the breast, uterus, and bilateral adnexa was performed for all female workers, and routine gynecological examination, routine leucorrhea examination, and thinprep liquid-based cytology test were performed for married female workers. The detection rates of breast and gynecological diseases in female workers in the administrative office and workshop were analyzed. Results: In the 314 female workers, the overall detection rate of breast and gynecological diseases was 86.31%; the detection rate of abnormal breast ultrasound results was 72.93%, mainly breast hyperplasia; the detection rate of abnormal gynecological ultrasound results was 12.14%, mainly hysteromyoma, pelvic effusion, and uterus-rectum fossa effusion. The overall detection rate of cervicitis or vaginitis in married female workers was 66.86%. The univariate analysis showed that compared with those in the administrative office, the female workers in the workshop had significantly higher detection rates of breast hyperplasia and grade 2 breast lesions on the Breast Imaging-Reporting and Data System (BI-RADS) and significantly lower detection rates of hysteromyoma and grade 3 breast lesions on the BI-RADS (all P <0.05) . The multivariate analysis showed that age was a risk factor for hysteromyoma (OR=1.261) , age and working in the workshop were risk factors for breast hyperplasia (OR=1.065 and 1.834) , married status was a protective factor against breast hyperplasia and grade 2 breast lesions on the BI-RADS (OR=0.334 and 0.450) , and working in workshop was a risk factor for grade 2 breast lesions on the BI-RADS (OR=1.890) and a protective factor against grade 3 breast lesions on the BI-RADS (OR=0.355) . Conclusion: Female workers in an automobile part factory have high prevalence rates of breast and gynecological diseases. Night shifts for female workers in the workshop should be reduced as much as possible, and female workers, especially those in the administrative office, should be guided to release pressure and take a balanced diet.

Expression and activation of ß-adrenoceptors in the colorectal mucosa of rat and human.

BACKGROUND: The functions of the distal colon are regulated by local and extrinsic neural pathways. In previous studies, we have found that dopamine (DA) and norepinephrine (NE) could evoke colonic ion transport by activating ß-adrenoceptors. The present study aims to investigate the segmental differences in expression and activation of ß-adrenoceptors in the distal colon in physiological and pathophysiological conditions. METHODS: Real-time PCR, immunofluorescence, and Western blotting were used to detect the expression of ß-adrenoceptors in the rat and human distal colon. Short-circuit current measurements (Isc) were used to assess the role of ß-adrenoceptors in ion transport. KEY RESULTS: DA and NE caused greater suppression of baseline Isc in distal colon adjacent to the rectum than in segments further away from the anus. These responses were inhibited by selective antagonists of ß1- and ß2-adrenoceptors, but not ß3-adrenoceptor. The expression levels of ß1- and ß2-adrenoceptors in colonic mucosa were higher in colorectum than the regions away from the anus of rats and humans. In wrap-restraint stress (2 h), DA-, NE-induced ΔIsc and the expression of ß-adrenoceptors in the colorectum were significantly reduced. However, when endogenous catecholamines were depleted by 6-hydroxydopamine (75 mg kg(-1), i.p., 3 days), DA-, NE-induced ΔIsc as well as the expression of ß-adrenoceptors were significantly enhanced in the rat colorectum but not in more proximal regions of the distal colon. CONCLUSIONS & INFERENCES: ß1- and ß2-adrenoceptors are predominantly expressed in the colorectal mucosa. Perturbation of endogenous catecholamine levels influences the expression and activation of ß-adrenoceptors in the colorectal region.