氧化损伤与噪声性听力损失

噪声性聋是一种常见的职业病,随着人们对该疾病认识的逐渐深入,针对其发病机制也提出了不同的防治方法.现就目前已得到大多数学者认同的氧化损伤机制及针对该机制的一些防治措施做一综述.     

甲硫氨酸对噪声性听力损失的预防作用研究

目的：探讨口服甲硫氨酸对噪声性听力损失的预防作用。方法将解放军某部健康男性军人203例随机分为试验组（113例）和对照组（90例）,均给予脉冲噪声（峰值160～170 dB SPL）暴露1小时,暴露前3天试验组口服甲硫氨酸片1500 mg/日×3天,对照组则口服等剂量安慰剂（淀粉）。两组受试者噪声暴露前后行纯音测听、听性脑干反应听（ABR）检查,对检查结果进行统计学分析。结果噪声暴露后1天,两组各频率纯音听阈均高于暴露前（P＜0．05或 P＜0．01）,暴露后7天,对照组纯音听阈仍升高（P＜0．05）,而试验组与暴露前比较差异无统计学意义（P＞0．05）;噪声暴露前、暴露后1天、7天,试验组 ABR 反应阈分别为40．5±9．3、51．7±12．3、44．1±11．4 dB nHL,对照组分别为41．5±8．9、62．4±13．7、47．6±12．5 dB nHL,试验组 ABR I－V 波间期分别为3．72±0．21、3．99±0．36、3．82±0．25 ms,对照组分别为3．71±0．22、4．45±0．37、3．85±0．34 ms,噪声暴露后1、7天两组间 ABR 反应阈、I－V 波间期比较差异有统计学意义（P＜0．05或 P＜0．01）。结论噪声暴露前口服甲硫氨酸片能有效减轻噪声暴露后噪声性听力损失的发生。     

水杨酸钠对噪声性听力损失影响的实验

目的 观察水杨酸钠能否减轻噪声引起的听力损失。方法 将３６只健康且耳廓反射正常的花色豚鼠随机分为水杨酸钠实验组、生理盐水对照组、水杨酸钠对照组和噪声暴露组。噪声暴露采用１０５ｄＢ ＳＰＬ的４ＫＨｚ窄带噪声下暴露２ｈ,连续５ｄ。水杨酸钠给药为每天０．５ｇ／ｋｇ体重连续１０ｄ。由短声诱发听性脑干反应（ａｕｄｉｔｏｒｙ ｂｒａｉｎｓｔｅｍ ｒｅｓｐｏｎｓｅ,ＡＢＲ）,连续测试其阈值;而后取动物双侧耳蜗荧     

水杨酸钠对噪声性听力损失影响的实验观察

目的　观察水杨酸钠能否减轻噪声引起的听力损失。方法　将 3 6只健康且耳廓反射正常的花色豚鼠随机分为水杨酸钠实验组、生理盐水对照组、水杨酸钠对照组和噪声暴露组。噪声暴露采用 10 5dBSPL的 4kHz窄带噪声下暴露 2h ,连续 5d。水杨酸钠给药为每天 0 5g/kg体重连续10d。由短声诱发听性脑干反应 (auditorybrainstemresponse ,ABR) ,连续测试其阈值 ;而后取动物双侧耳蜗荧光染色后光镜下行毛细胞计数和形态学观察。结果　ABR阈值测试显示 ,实验组动物在噪声暴露结束后 2 4h的听力略好于对照组 ;形态学观察表明 ,实验组细胞核异常数据低于对照组。结论　水杨酸钠可能在一定程度上具有拮抗噪声引起的听力损失及保护耳蜗毛细胞的作用     

多巴胺对豚鼠噪声性听力损失的保护作用

目的观察白噪声条件下多巴胺（dopamine,DA）对耳蜗内毛细胞的保护作用,为进一步探讨多巴胺对耳蜗传入通路的负反馈保护机制奠定基础。方法健康杂色豚鼠40只,随机分4组,行活体全耳蜗灌流：①单纯给予100dB白噪声组（以下同）;②灌流人工外淋巴液组;③灌流人工外淋巴液并给予白噪声组;④灌流1mmol/L多巴胺并给予白噪声组。在灌流第0、2h记录4kHz耳蜗微音电位（cochlear mirophonics,CM）幅值,并做相对幅度输入/输出函数曲线,和不同频率复合动作电位（compound action potential,CAP）阈值。结果给予噪声暴露的3组灌流后CM输入/输出曲线非线性特点均消失,相对幅度下降,差异有统计学意义（P〈0.05）。给予噪声暴露的3组2小时后各频率CAP阈值较前均上升,差异有统计学意义（P〈0.001）。但第4组较第1组除8kHzCAP阈移差异无统计学意义外,其余各频率CAP阈移明显减小（P〈0.05）。高频的阈移相差程度均较低频明显,其中16kHz阈移相差程度最为明显。结论白噪声暴露下多巴胺对耳蜗传入通路具有保护作用,并存在频率选择性,对高频纤维保护作用较低频更强。     

雌激素对小鼠风洞噪声性听力损伤的保护作用

目的探讨雌激素对暴露于风洞噪声小鼠听觉电生理及耳蜗形态学改变的影响,为噪声性耳聋的预防提供依据。方法 60只小鼠随机分为A、B、C三组,每组20只,三组小鼠分别暴露于风洞模拟噪声环境中,每天8小时,连续7天。B组于暴露噪声前30min肌肉注射苯甲酸雌二醇0.15mg/只,C组暴露噪声结束后30min肌肉注射苯甲酸雌二醇0.15mg/只。分别于实验前、接噪3天、接噪7天、脱噪恢复3天、脱噪恢复7天后测试各组小鼠脑干诱发电位(ABR)阈值,取耳蜗标本行扫描电镜检查。结果三组小鼠在接噪3天、接噪7天的ABR阈值均比实验前增高,但组间无明显差异。三组小鼠在脱噪恢复3天、脱噪恢复7天ABR阈值均比接噪7天有恢复,但雌激素治疗组较其余两组恢复效果明显。扫描电镜显示单纯噪声组损伤最重,雌激素预防组损伤次之,雌激素治疗组损伤最轻。结论风洞噪声能造成小鼠听觉电生理及耳蜗形态学的改变;雌激素对小鼠风洞噪声性耳聋有保护作用;雌激素治疗组保护效果较雌激素预防组明显。     

重视噪声性听力损害的早期识别

噪声可引起多系统损害,其中对听觉系统的永久性损害最为严重。全球约5%~12%人口表现为不同程度的噪声性聋。噪声损害初期多表现为轻度耳鸣、隐性听力损失或暂时性高频听力损失;随着噪声接触时间的延长,耳鸣和听力损失加重,最终导致永久性听力损失,同时引起言语识别阈提高和言语识别率减低;部分患者还可出现失眠、焦虑、眩晕、头痛等症状。因此,重视噪声性听力损害,对噪声接触人群进行早期筛查具有重要意义。本文通过分析国内外研究现状,将噪声性聋的早期筛查方法归纳为畸变产物耳声发射测试、高频纯音测听、言语测听、互联网筛查、耳鸣评估、心理健康水平评估和易感基因筛查等,为临床应用提供参考依据。     

MK-801拮抗水杨酸钠致螺旋神经节细胞损伤的实验研究

目的探讨非特异性阻断NMDA受体拮抗水杨酸钠对离体培养螺旋神经节细胞兴奋性损伤的作用。方法将培养的耳蜗螺旋神经节细胞随机分为3组,分别为正常对照组:培养液中仅加入1mM谷氨酸;水杨酸钠组:1mM谷氨酸+5mM水杨酸钠;MK-801组:50μM MK-801+1mM谷氨酸+5mM水杨酸钠。培养24h后加药物干预3h,收集细胞采用实时荧光定量PCR及免疫荧光技术检测BDNF exonⅣ,BDNF exonⅥ转录及Caspase-3mRNA转录和蛋白表达的改变,研究应用MK-801非特异性阻断NMDA受体拮抗水杨酸钠对离体培养螺旋神经节细胞兴奋性损伤的作用。结果水杨酸钠组较谷氨酸组及MK-801组螺旋神经节细胞中BDNF exonⅣ,BDNF exonⅥ和Caspase-3 mRNA的转录及Cas-pase-3蛋白的表达水平显著增高(P值均<0.05);BDNF exonⅣ的转录在MK-801组较谷氨酸组明显降低(P<0.05);BDNF exonⅥ的转录在MK-801组较谷氨酸组未发生具有统计学意义的改变;Caspase-3的转录及蛋白的表达在MK-801组较谷氨酸组显著提高(P<0.05)。结论非特异性阻断NMDA受体能拮抗水杨酸钠引起的离体培养螺旋神经节细胞中BDNFexonⅣ,BDNFexonⅥ及Caspase-3上调。     

噪声性听力损失早期发现与诊断方法研究进展

噪声性听力损失（noise induced hearing loss,NIHL）系由于人们听觉长期遭受噪声强烈影响而发生缓慢的一种双侧进行性高频下降型感音神经性听力损失。NIHL是成人听力损失的主要原因之一,近年来其发病率逐年上升,不仅影响人们的日常交流,而且还会对人的心理健康产生负面影响,从而降低人们的生活质量。NIHL虽然是永久的、不可逆的,但却可以预防,因此早期发现与早期诊断防止其扩展至言语频率就显得尤为重要。现有的听力检测方法主要依赖于常规纯音测听,然而由于其敏感性较差,对早期听力损失不能做到及时发现和诊断。因此,扩展高频测听和畸变产物耳声发射等能够早期检测到内耳毛细胞功能障碍的方法逐渐成为人们研究的对象。本文就NIHL早期发现与诊断方法的研究进行综述。     

一氧化氮合酶抑制剂和神经营养因子3对噪声暴露下豚鼠耳蜗的保护作用

目的观察一氧化氮合酶抑制剂——N-硝基左旋精氨酸甲酯（N^G-nitro-L-arginine methyl ester，L-NAME）和神经营养因子3（neurotrophin 3，NT3）对噪声性听力损失的保护作用。方法80只雄性杂色豚鼠按区组随机分为非噪声组（n=20）和噪声暴露组（n=60），噪声暴露组又分为生理盐水组（n=20）、L-NAME组（n=20）、L-NAME＋NT3组（n=20）。L-NAME组和L-NAME＋NT3组动物在噪声暴露（4kHz倍频程、声压级115dB，5h）之前2d和噪声暴露前30min给予L-NAME 10mg／kg（腹腔注射），生理盐水组动物给予等体积的生理盐水。NT3（10μg／ml）在噪声暴露前4d经微量渗透泵（200μl，0．5μl／h）输入到L-NAME＋NT3组动物的右侧耳蜗鼓阶，持续到噪声暴露后10d。噪声暴露前和暴露后10d测试听性脑干反应（auditory brainstem response，ABR），暴露后3d测试耳蜗组织一氧化氮（nitric oxide，NO）水平，最后一次ABR测试后计数耳蜗毛细胞的存活率。结果无噪声暴露组动物无明显的听力改变和毛细胞缺失；生理盐水组动物的ABR阈移、毛细胞缺失率及耳蜗组织NO水平均高于L-NAME组和L-NAME＋NT3组，差异有统计学意义（P值均〈0．01）；与L-NAME组相比，L-NAME＋NT3组豚鼠的ABR阈移减小，差异有统计学意义（P〈0．01），而耳蜗组织NO水平和毛细胞缺失率差异则没有统计学意义（P=0．197及P=0．095）。结论与单独给予L-NAME相比，联合使用NT3可以更大程度减轻噪声对豚鼠耳蜗的损伤。     

The protective effect of adrenocorticotropic hormone treatment against noise-induced hearing loss

Objective

NIHL is a common problem, and steroids are the most effective treatment option. In this study, we aimed to evaluate the protective effects of the synthetic adrenocorticotropic hormone (ACTH) analogues, which induce endogenous steroid secretion, against noise-induced hearing loss (NIHL) and to compare their effectiveness with that of steroid treatment.

Sensorineural high-frequency hearing loss after drill-generated acoustic trauma in tympanoplasty

Summary Tympanoplasty can cause a sensorineural hearing loss by a mechanism of acoustic trauma. Although this lesion appears to be relatively infrequent in clinical practice, we believe that its low apparent incidence is caused when clinicians fail to assess the auditory frequencies above 8000 Hz. Twenty-four patients with normal bone-conduction audiometric thresholds scheduled for tympanoplasty were assessed with an electro-stimulation, bone-conduction high-frequency audiometer which can measure hearing frequencies up to 20 kHz before and after surgery. A measurable hearing loss was found in the upper limits of the audible frequencies in 9 patients (37.5%), and was considered important in 4 of them (16.7%). This hearing loss was recorded above the upper frequency limit of conventional audiometers. The findings in this study indicate that drilling of the temporal bone can impair the hearing level in the high frequencies in a significant number of patients. High-frequency audiometry is a very sensitive tool to assess any damage caused to the inner ear by surgical procedures carried out in the middle ear and temporal bone.Presented at the First European Congress of Oto-Rhino-Laryngology and Cervico-Facial Surgery, Paris, 26–29 September 1988     

Effects of early intratympanic steroid injection in patients with acoustic trauma caused by gunshot noise

Conclusion: This study evaluated the efficacy of concurrent administration of ITSI and systemic steroids in delayed treatment of NIHL after gunshot noise exposure. The results showed additional hearing benefits with administration of ITSI. Further evaluation is warranted to confirm this efficacy.

Objective: This investigation evaluated the effects of early administration of an intratympanic steroid injection (ITSI) in combination with systemic steroids treatment in patients with acoustic trauma caused by gunshot noise.

Methods: Nineteen patients eligible under the criteria established concerning delayed treatment for noise-induced hearing loss (NIHL) were enrolled in this study. Patients were divided into two groups: those who received prednisolone (PD) only (n?=?8), and those who received PD with ITSI (n?=?11). ITSI treatment was initiated simultaneously alongside systemic PD administration. These patients received ITSI every other day for a total of four treatments. Pure-tone air conduction threshold audiometry, to record the pure-tone average (PTA) at 2, 4, and 8?kHz, was conducted upon each patient’s initial visit, and 1 month after starting treatment, to evaluate the degree of hearing gain (hearing gain (dB)?=?(initial PTA) – (final PTA)).

Results: The initial PTA in PD-only and PD with ITSI groups were 52.75?±?15.50?dB and 50.27?±?12.01?dB, respectively. There were no significant differences in the baseline characteristics of the two groups, which include age and the number of days that treatment was delayed. In the multivariable linear regression analysis, both the initial PTA and the treatment method showed a significant association (R^2?=^?0.41). The unstandardized regression coefficient of the initial PTA was 0.47 (p?=?0.02). Patients with additional ITSI showed significant improvement in the degree of hearing gain compared with the PD-only group (unstandardized regression coefficient =11.48, p?=?0.03)     

N-乙酰半胱氨酸对噪声性聋的预防作用研究

目的:探讨口服N-乙酰半胱氨酸对噪声性聋的预防作用。方法:选择某部入伍1年以上健康军人363例作为受试者,随机分为实验组(223例)和对照组(140例),2组分别给予口服N-乙酰半胱氨酸和安慰剂,用法1 200mg/d×14d。2组受试者噪声暴露前、后均行纯音测听和ABR检查,对检查结果进行统计学分析。结果:2组受试者噪声暴露前后听力均有改变,组间差异有统计学意义。结论:口服N-乙酰半胱氨酸能有效减轻噪声暴露后噪声性聋的发生。     

Effects of intratympanic dexamethasone on noise-induced hearing loss: An experimental study

Aim

Aim of the study was to evaluate the effect of intratympanic steroid treatment on hearing based on oto-acoustic emission.

Differences between acoustic trauma and other types of acute noise-induced hearing loss in terms of treatment and hearing prognosis

Abstract

Objectives: To evaluate the differences between acoustic trauma (AT) and other types of acute noise-induced hearing loss (ANIHL), we performed a literature search and case reviews.

Methods: The literature search based on online databases was completed in September 2016. Articles on ANIHL and steroid treatment for human subjects were reviewed. The source sounds and treatment sequelae of our accumulated cases were also reviewed. Hearing loss caused by gun-shots and explosions was categorized into the AT group, while hearing loss caused by concerts and other noises was categorized into the ANIHL group.

Results: Systemic steroid treatment did not appear to be effective, at least in the AT group, based on both the literature and our case reviews. However, effective recovery after treatment including steroids was observed in the ANIHL group. The difference in hearing recovery between the AT and ANIHL groups was statistically significant (p?=?.030), although differences in age, days from the onset to treatment and pretreatment hearing levels were not significant.

Conclusions: Hearing recovery from AT is very poor, whereas, ANIHL is recoverable to some extent. Therefore, it is essential to differentiate between these two groups for accurate prediction of the hearing prognosis and evaluation of treatment effects.     

Guidelines on the diagnosis of noise‐induced hearing loss for medicolegal purposes

These guidelines aim to assist in the diagnosis of noise‐induced hearing loss (NIHL) in medicolegal settings. The task is to distinguish between possibility and probability, the legal criterion being ‘more probable than not’. It is argued that the amount of NIHL needed to qualify for that diagnosis is that which is reliably measurable and identifiable on the audiogram. The three main requirements for the diagnosis of NIHL are defined: R1, high‐frequency hearing impairment; R2, potentially hazardous amount of noise exposure; R3, identifiable high‐frequency audiometric notch or bulge. Four modifying factors also need consideration: MF1, the clinical picture; MF2, compatibility with age and noise exposure; MF3, Robinson's criteria for other causation; MF4, complications such as asymmetry, mixed disorder and conductive hearing impairment.     

Epidemiology of hearing loss in childhood

During a 20-year period, half a million screening audiograms have been obtained on children at schools in Stockholm. The incidence of hearing loss in children of a particular age did not differ appreciably over the 14-year period analysed. In the age groups from 4 to 16, the incidence of temporary conductive hearing impairment decreased with age, whereas the incidence of permanent defects and particularly sensorineural high-frequency loss showed an increase with age.

For conductive hearing impairments there was no sex difference but for sensorineural defects there was a definite prepoderance of boys which was observed as early as 7 years of age.

The results of this general survey of the total material are supplemented and verified by the findings recorded in a more thorough examination at schools in Stockholm of all 13-year-old children born in 1948. The discussion of the results leads to the opinion that high-frequency loss in children would seem to be to a large extent of genetic origin.     

突发性耳聋治疗的统计分析

目的５０４例突发性耳聋患者。方法对采用的十二种突聋治疗方案进行回顾性分析。结果各治疗组的疗效均有差异（Ｐ＜０．０５）,以血管内Ｈｅ—Ｎｅ激光、高压氧和铁剂的疗效为佳。结论突聋以综合治疗为主,血管内激光、高压氧和铁剂也有重要作用。