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Tympanic membranes (TM) that have healed spontaneously after perforation present abnormalities in their structural and mechanical properties; i.e., they are thickened and abnormally dense. These changes result in a deterioration of middle ear (ME) sound transmission, which is clinically presented as a conductive hearing loss (CHL). To fully understand the ME sound transmission under TM pathological conditions, we created a gerbil model with a controlled 50% pars tensa perforation, which was left to heal spontaneously for up to 4 weeks (TM perforations had fully sealed after 2 weeks). After the recovery period, the ME sound transmission, both in the forward and reverse directions, was directly measured with two-tone stimulation. Measurements were performed at the input, the ossicular chain, and output of the ME system, i.e., at the TM, umbo, and scala vestibuli (SV) next to the stapes. We found that variations in ME transmission in forward and reverse directions were not symmetric. In the forward direction, the ME pressure gain decreased in a frequency-dependent manner, with smaller loss (within 10 dB) at low frequencies and more dramatic loss at high frequency regions. The loss pattern was mainly from the less efficient acoustical to mechanical coupling between the TM and umbo, with little changes along the ossicular chain. In the reverse direction, the variations in these ears are relatively smaller. Our results provide detailed functional observations that explain CHL seen in clinical patients with abnormal TM, e.g., caused by otitis media, that have healed spontaneously after perforation or post-tympanoplasty, especially at high frequencies. In addition, our data demonstrate that changes in distortion product otoacoustic emissions (DPOAEs) result from altered ME transmission in both the forward and reverse direction by a reduction of the effective stimulus levels and less efficient transfer of DPs from the ME into the ear canal. This confirms that DPOAEs can be used to assess both the health of the cochlea and the middle ear.  相似文献   
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ABSTRACT BACKGROUND Hepatitis-associated aplastic anemia (HAAA) is a rare condition. Patients with HAAA usually present with acute hepatitis, jaundice and significantly increased transaminase. After 1–2 mo, hepatitis gradually improves, but progressive hemocytopenia, bone marrow hematopoietic failure, and severe or extremely severe aplastic anemia are manifest. Most cases of HAAA are fulminant and usually lethal if left untreated. The literature on Epstein–Barr virus (EBV)-associated HAAA is sparse. CASE SUMMARY We report a 30-year-old man who was admitted to our hospital because of pale yellow urine and skin with a simultaneous decrease in peripheral blood ternary cells. We made a diagnosis of EBV-associated HAAA. The treatment strategy for this patient included eltrombopag, an immunosuppressive regimen of rabbit anti-human thymocyte immunoglobulin, cyclosporine, and supportive care. The patient was discharged in normal physical condition after five months. A hemogram performed on follow-up revealed that he had achieved a complete response. CONCLUSION Eltrombopag plus anti-thymocyte globubin and cyclosporine may be a therapeutic option for EBV-associated HAAA.Larger studies are warranted to confirm.  相似文献   
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陈梅珠  罗琳  田毅 《河北医学》2022,28(2):267-271
目的:探讨血清白介素17A(IL-17A)、食欲素A(OXA)对老年髋部骨折全麻术术后认知功能障碍的预测价值及影响因素分析.方法:选取本院185例老年髋部骨折全麻术患者作为研究对象,根据术后认知功能障碍分为认知功能障碍组(POCD组,51例)和非认知功能障碍组(NPOCD组,134例).采用酶联免疫吸附试验法检测血清IL-17A和OXA水平,绘制受试者工作曲线(ROC)分析血清IL-17A、OXA水平对POCD的预测价值,同时应用多因素logistics回归分析POCD的影响因素.结果:与术前比较,术后两组血清IL-17A水平明显上升(P<0.01),而OXA水平明显下降(P<0.01).术后与NPOCD组比较,POCD组血清IL-17A水平升高(P<0.01),而OXA水平降低(P<0.01).ROC曲线分析显示,血清IL-17A和OXA对POCD预测最佳截断值分别为33.96pg/mL、249.70pg/mL,AUC分别为0.843和0.799.Logistic回归分析显示,年龄、术前合并症种类数≥3、血清IL-17A≥33.96pg/mL和OXA≤249.70pg/mL是POCD的影响因素.结论:血清IL-17A和OXA水平与老年髋部骨折全麻术术后认知功能障碍密切相关,可作为预测POCD的生物标志物.  相似文献   
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基于国家深化高等院校课程建设的新时代视域,提升课程质量成为高校教育教学发展的重要任务。地方医学院校作为基层卫生人才的培养摇篮,构建科学合理的课程质量监控体系愈发迫切。本文分析了我国高等院校课程质量监控体系存在的问题,结合地方医学院校办学特点和广州医科大学工作实践,探索构建了集“多样化监控方法、全维度监控指标、闭环式反馈机制、多层级文化建设”为一体的课程质量监控体系,为同类院校提供实际参考。  相似文献   
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BACKGROUND Esophageal squamous cell carcinoma(ESCC)is one of the most prevalent malignancies that seriously threaten people’s health worldwide.DEAD-box helicase 51(DDX51)is a member of the DEAD-box(DDX)RNA helicase family,and drives or inhibits tumor progression in multiple cancer types.AIM To determine whether DDX51 affects the biological behavior of ESCC.METHODS The expression of DDX51 in ESCC tumor tissues and adjacent normal tissues was detected by Immunohistochemistry(IHC)analyses and quantitative PCR(qPCR).We knocked down DDX51 in ESCC cell lines by using a small interfering RNA(siRNA)transfection.The proliferation,apoptosis,and mobility of DDX51 siRNAtransfected cells were detected.The effect of DDX51 on the phosphoinositide 3-kinase(PI3K)/AKT pathway was investigated by western blot analysis.A mouse xenograft model was established to investigate the effects of DDX51 knockdown on ESCC tumor growth.RESULTS DDX51 exhibited high expression in ESCC tissues compared with normal tissues and represented a poor prognosis in patients with ESCC.Knockdown of DDX51 induced inhibition of ESCC cell proliferation and promoted apoptosis.Moreover,DDX51 siRNA-expressing cells also exhibited lower migration and invasion rates.Investigations into the underlying mechanisms suggested that DDX51 knock down induced inactivation of the PI3K/AKT pathway,including decreased phosphorylation levels of phosphate and tensin homolog,PI3K,AKT,and mammalian target of rapamycin.Rescue experiments demonstrated that the AKT activator insulin-like growth factor 1 could reverse the inhibitory effects of DDX51 on ESCC malignant development.Finally,we injected DDX51 siRNA-transfected TE-1 cells into an animal model,which resulted in slower tumor growth.CONCLUSION Our study suggests for the first time that DDX51 promotes cancer cell proliferation by regulating the PI3K/AKT pathway;thus,DDX51 might be a therapeutic target for ESCC.  相似文献   
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