Previous animal studies have shown that stromal cell-derived factor-1 （SDF-1）/CXC chemokine receptor-4 （CXCR4） signaling pathway plays an important role in the targeted migration of bone marrow-derived mesenchymal...Previous animal studies have shown that stromal cell-derived factor-1 （SDF-1）/CXC chemokine receptor-4 （CXCR4） signaling pathway plays an important role in the targeted migration of bone marrow-derived mesenchymal stem cells （BMSCs） to the injured area. In the present study, we aimed to investigate the potential role of chemotactic SDF-1/CXCR4 signaling pathway in the homing of transplanted BMSCs to the injured cochlea after noise-induced hearing loss （NIHL） in a rat model. White noise exposure （110 dB） paradigm was used for hearing loss induction in male rats for 6 hours in 5 days. Distortion-product otoacoustic emission （DPOAE） responses were recorded before the experiment and post noise exposure.Hoechst 33342-labeled BMSCs and CXCR4 antagonist （AMD3100）-treated BMSCs were injected into the rat cochlea through the round window. SDF-1 protein expression in the cochlear tissue was assayed using western blot assay. The number of labeled BMSCs reaching the endolymph was determined after 24 hours.SDF-1 was significantly increased in the cochlear tissue of rats in the noise exposure group than in the control group. The number of Hoechst 33342-labeled BMSCs reaching the endolymph of the cochlea was significantly smaller in the AMD3100-treated BMSCs group than in the normal BMSCs group. Our present findings suggest that the SDF-1/CXCR4 signaling pathway has a critical role in BMSCs migration to the injured cochlea in a rat model of noise-induced hearing loss.展开更多
Objective： To report audiological characteristics in a group of noise-exposed crew members on board ships. Methods and materials： Clinical and audiological measurements including pure-tone thresholds, acoustic immit...Objective： To report audiological characteristics in a group of noise-exposed crew members on board ships. Methods and materials： Clinical and audiological measurements including pure-tone thresholds, acoustic immittance results and tinnitus questionnaires were collected from both the ship crew members （study subjects） and their land based colleagues （controls）. Results： 1） Noise exposed crew members showed not only high frequency, but also low frequency hearing loss; 2） Hearing impairment increased with age, with 65.5% of crew members younger than 50 years showing normal hearing while only 14.9% of those older than 50 years had normal hearing; 3） hearing loss gradually increased with the extension of on board career time; and 4） Most study subjects reported high pitch tinnitus, significantly more than the control group although not significantly different among different age groups. Conclusion： Noise induced hearing impairment from working on board ships shows specific frequency and age characteristics. Understanding these characteristics is important for advancing relevant studies and for effective prevention of noise-induced hearing loss in ship crew members.展开更多
基金financially supported by the Hearing Disorders Research Center of Shahid Beheshti University of Medical Sciences
文摘Previous animal studies have shown that stromal cell-derived factor-1 （SDF-1）/CXC chemokine receptor-4 （CXCR4） signaling pathway plays an important role in the targeted migration of bone marrow-derived mesenchymal stem cells （BMSCs） to the injured area. In the present study, we aimed to investigate the potential role of chemotactic SDF-1/CXCR4 signaling pathway in the homing of transplanted BMSCs to the injured cochlea after noise-induced hearing loss （NIHL） in a rat model. White noise exposure （110 dB） paradigm was used for hearing loss induction in male rats for 6 hours in 5 days. Distortion-product otoacoustic emission （DPOAE） responses were recorded before the experiment and post noise exposure.Hoechst 33342-labeled BMSCs and CXCR4 antagonist （AMD3100）-treated BMSCs were injected into the rat cochlea through the round window. SDF-1 protein expression in the cochlear tissue was assayed using western blot assay. The number of labeled BMSCs reaching the endolymph was determined after 24 hours.SDF-1 was significantly increased in the cochlear tissue of rats in the noise exposure group than in the control group. The number of Hoechst 33342-labeled BMSCs reaching the endolymph of the cochlea was significantly smaller in the AMD3100-treated BMSCs group than in the normal BMSCs group. Our present findings suggest that the SDF-1/CXCR4 signaling pathway has a critical role in BMSCs migration to the injured cochlea in a rat model of noise-induced hearing loss.
基金supported by the National Basic Research Program of China(973 Program)(2014CB943002)the National Natural Science Foundation of China(81470700)Noise Grant(BWS14J045)
文摘Objective： To report audiological characteristics in a group of noise-exposed crew members on board ships. Methods and materials： Clinical and audiological measurements including pure-tone thresholds, acoustic immittance results and tinnitus questionnaires were collected from both the ship crew members （study subjects） and their land based colleagues （controls）. Results： 1） Noise exposed crew members showed not only high frequency, but also low frequency hearing loss; 2） Hearing impairment increased with age, with 65.5% of crew members younger than 50 years showing normal hearing while only 14.9% of those older than 50 years had normal hearing; 3） hearing loss gradually increased with the extension of on board career time; and 4） Most study subjects reported high pitch tinnitus, significantly more than the control group although not significantly different among different age groups. Conclusion： Noise induced hearing impairment from working on board ships shows specific frequency and age characteristics. Understanding these characteristics is important for advancing relevant studies and for effective prevention of noise-induced hearing loss in ship crew members.
文摘目的探讨某石化企业噪声暴露与噪声性听力损失(NIHL)之间的剂量-反应关系。方法 2015年6—7月将某石化企业接噪工人按工作地点、工种和班次分为不同亚组,每组选择3~5人,共290人。采用HS6280个体噪声计量仪测定噪声暴露。同时进行问卷调查和听力检查,应用SPSS17.0统计软件进行数据分析。结果接噪工人8 h连续等效A声级(LAeq.8h)中位值为89.1 d B(A);290名研究对象中患高频听力损失(HFNIH)141人(48.6%),患语频听力损失19人(6.6%);以噪声级为测量指标,工人NIHL患病率未表现出随噪声暴露增加而升高的趋势;而按照噪声级与工龄合并后的累积噪声暴露量评价,HFNIH患病率随噪声暴露增加而升高。结论接噪工人噪声暴露与HFNIH患病率之间存在剂量-反应关系;累积噪声暴露量是评价非稳态噪声暴露的良好指标。
