对乙酰氨基酚致听力损伤的研究进展

<正>听力损伤是一种常见的疾病,世界卫生组织(WHO)的世界疾病排列表中,听力损伤名列第15位[1]。众多听力损伤的患者中,药物所致的听力损伤占有相当大的部分。对乙酰氨基酚是一种非抗炎解热镇痛药,被广泛应用于发热,轻中度疼痛。近年来越来越多的流行病学研究表明,使用一定剂量的对乙酰氨基酚能引起听力受损。为进一步了解对乙酰氨基酚引起听力损伤的机制,预防和减少因使用对乙酰氨基酚所致的药物性耳聋,本文对国内外近些年报     

外淋巴瘘的毛细胞凋亡与听力损伤

目的：为探讨外淋巴瘘时的毛细胞凋亡现象及其在听力损伤中的作用。方法：对２５只豚鼠行外淋巴瘘造模后利用光镜,ＴＵＮＥＬ标记技术,耳蜗电图及脑干诱发电位等检测指标。结果：（１）外淋巴瘘早期（０ｈ组,２ｈ组）８只豚鼠形态正常,无毛细胞凋亡,随着外淋巴瘘时程延长,毛细胞凋亡数增多,耳蜗毛细胞凋亡出现概率分别为造瘘后１ｄ组（１／６只）,２ｄ组６７％（４／６只）和７ｄ组８０％（４／５只）;（２）外淋巴瘘造模后     

中枢听觉加工损伤

人类的听觉系统分为外周听觉系统和中枢听觉加工系统（central auditory processing,CAP）,即由执行大脑听觉模式加工功能的神经系统组成。外周听觉系统的损伤比较容易诊断。与外周听觉系统不同的是,中枢听觉加工系统主要负责从外周听觉系统传人的神经冲动中提取有用的听觉信息。中枢听觉加工系统的损伤（central auditory processing disorders,CAPD）无法通过常规的听力测试检测出来。事实上,对多数CAPD孩子进行听力检查,结果都是完全正常的,有时甚至是过于敏感的。但是．这些孩子在特定的情景下对声音的加工会出现问题,这些问题突出表现在对中枢听觉功能的综合测试中。     

大鼠慢性氟中毒听觉损伤的实验观察

目的探讨慢性氟中毒大鼠耳蜗毛细胞形态学的改变和听力损失的机制。方法借助畸变产物耳声发射（distortion product otoacoustic emissions，DPOAE）测试和扫描电镜技术，对60只大鼠进行了实验观察。结果DPOAE测试结果显示对照组与低氟组、高氟组8kHz反应幅值差异均有显著性（P〈0．05），0．5、1、2、4kHz各组数据经统计学处理（P〉0．05），无统计学意义。对照组耳蜗内、外毛细胞排列规则。低氟组的内、外毛细胞都有不同程度的损害，表现为静纤毛粘连、倒伏。高氟组内、外毛细胞的损害严重，出现明显的粘连、倒伏、融合，并可见散在的节段性缺失，以底圈明显。表皮板结构发生不同程度的病变，严重者表皮板穿孔，细胞内容物流出，形成气球样改变。结论慢性氟中毒明显影响听力，导致高频感音神经性耳聋，其损害机制可能是氟对耳蜗毛细胞的直接损害造成的。听功能损害的严重程度与氟中毒程度相关。     

冲击波对豚鼠耳蜗毛细胞碳酸酐酶的影响

用组织化学、细胞化学方法结合图像分析和听觉电生理技术,研究了冲击波对豚鼠耳蜗毛细胞碳酸酐酶（ＣＡ）的影响及其与听阈阈移的关系。结果表明冲击波后６、１２、２４、４８、７２小时组,毛细胞中ＣＡ阳生产物的灰度值较正常组明显降低,其灰度值的变化与听觉脑干反应（ＡＢＲ）阈移呈负相关。提示毛细胞中ＣＡ活性减低是冲击波致听力损失的因素之一,文中讨论了ＣＡ在耳蜗毛细胞的作用及其与听阈的关系。     

石墨烯对氧化应激引起的毛细胞损伤的保护作用研究

目的 通过建立由H2O2诱导的HEI-OC1细胞氧化应激模型,验证石墨烯对氧化应激后毛细胞的保护作用,并探究石墨烯减轻毛细胞氧化应激损伤的可能机制.方法 我们将二维石墨烯材料(2D-G)作为实验组,TC玻片(TCPs)作为对照组.首先用不同浓度的H2O2处理接种于两种材料上的HEI-OC1细胞,分别作用4h和12h后,...     

庆大霉素致豚鼠前庭毛细胞破坏后再生及功能恢复

为探讨哺乳动物前庭毛细胞破坏后能否再生及前庭功能能否恢复，以豚鼠为研究对象。实验组动物每日给予庆大霉素皮下注射，连续１０天，对照组动物给予等量生理盐水。于停药后的第２、４、１２和２４周分别处死动物，扫描电镜观察发现，停药２周椭圆囊和壶腹嵴毛细胞破坏最明显的区域可见到不成熟的毛细胞纤毛丛，至停药２４周后继续存在。与对照组相比，停药１２周毛细胞密度下降明显（Ｐ〈０．０１），停药后２４周时毛细胞密度较１     

Prestin基因敲除小鼠听力和毛细胞改变的相关性研究

目的研究发育和成熟过程中的prestin基因敲除小鼠听力特征,比较其听力损害和外毛细胞(OHC)丧失的相关性,初步探讨OHC丧失的机制.方法利用听性脑干反应(ABR)、抗小鼠耳蜗毛细胞特异性的肌浆球蛋白7a(Mysojn 7a)抗体免疫染色和耳蜗连续切片观察出生后(postnatal,P)14天(P14)～P56的prestin基因敲除纯合子(prestin-/-)、杂合子(prestin /-)和野生型(prestin / )小鼠听阈、耳蜗毛细胞和Corti器的改变.结果P14的prestin-/-小鼠听阈较prestin / 升高25 dB SPL,至P21和P28,听阈分别提高49 dB和52 dB,P35后听阈改变不明显.在P21的prestin-/-小鼠,32 kHz听阈提高46 dB;prestin /-也显示约3.5 dB的听阈升高(p＜0.0001).Prestin-/-小鼠在P28以前无明显的OHC丧失,但是,OHC的长度较prestin / 明显缩短,P28以后,OHC丧失进行性加重.内毛细胞(IHC)丧失明显延迟和轻于OHC.结论Prestin-/-小鼠在毛细胞丧失之前呈现明显的听力损害,OHC的丧失可能与其本身的结构改变和成熟过程中的代谢异常有关.     

LittlEARS auditory questionnaire as an infant hearing screening in Germany after the newborn hearing screening

Objective: To investigate the feasibility of using the LittlEARS® Auditory Questionnaire (LEAQ®) as part of the infant hearing screening programme in Germany.

Design: LEAQ®s were distributed to 47 paediatric practices and were completed by the parents/guardians of the infants (aged between 9-14?months) involved in the study (= LEAQ^® screening). The infants who failed the LEAQ^® screening were invited to a LEAQ rescreening. Infants who failed the LEAQ^® rescreening were sent to a paediatric ENT specialist. After 3?years, a follow-up was performed on two groups: the first group comprised infants who failed the LEAQ screening; the second group (control group) comprised 200 infants who passed the LEAQ screening.

Study Sample: 5316 questionnaires were returned.

Results: Six infants with permanent hearing loss were identified using the LEAQ^® as a screening tool.

Conclusions: An infant hearing screening using the LEAQ^® is easily implementable in paediatric practices and may be a good alternative in countries where no objective screening instruments are available. The LEAQ^® was suitable for monitoring hearing development in infants in general and could help to identify a late-onset or progressive hearing loss in infants.     

听神经病病损部位分析

目的：探讨一组以言语听力下降为主的听力损失的命名、临床特点、病损部位。方法：分析１１例低频或以低频为主的感音神经性听力损失患者的临床症状、纯音测听、声导抗测试、听性脑干反应、耳蜗电图、畸变产物耳声发射～ＣＴ和（或）ＭＲＩ资料。结果：本组病例具有下列矛盾现象;主诉进行性听力闰退,尤其听不清语言,纯音听阈呈上升型听力图,听性脑干反应引不同或明显异常,甚经４０００Ｈｚ纯音听琢怕主观阈严重镫骨肌反引不出;     

Plasticity of the auditory system: theoretical considerations

Auditory plasticity refers to the possibility of anatomical and/or functional changes in the system where transmission of auditory information takes place. The auditory system is often required in communication; it is important to learn how the auditory system reacts to stimuli in order to improve performance in individual communication of subjects with impaired hearing.AimTo review the literature on auditory plasticity and the possibility and ability of plastic responses in the auditory system; also to review the evidence of auditory plasticity.MethodologyA review of the Brazilian and international literature (journals, books, and graduate studies) was carried out. The MEDLINE, SCIELO, BIREME, PUBMED, and LILACS data bases were consulted, as well as 24 papers from the 1990s to the present date; each paper was assessed for relevance to the topic.ConclusionThe findings showed that the auditory system is able to reorganize itself if there is variation, whether by by reducing, increasing, or conditioning of sound stimuli. This is evidence of plasticity in the auditory system.     

Correlation between the hair cell density and the auditory threshold in the white rat

The density of cochlear inner hair cells in Wistar rats is greatest on a short section of the basilar membrane about a fifth of its length from the base. This place corresponds to the frequency region of 30–40 kHz which is supposed to be region of best hearing.     

豚鼠听觉脑干电反应信号小波变换分析

目的：将小波变换这种时频域信号分析方法用于豚鼠听觉脑干电位分析,以了解小波变换是否适用于ＡＢＲ信号分析,较之传统法有否优越之处。方法 雄性纯白豚鼠３０只分成正常,传导性聋,感音性聋三组,每组１０只,要集各组７５ｄＢｎＨＬ短声诱发的ＡＢＲ,用小波处理软件进行变换,将变换前后信号的时域值作配对统计处理,结果 小波２尺度变换使原信号失真,４尺度变换增加原信号的背景噪声,３尺度变换可保持原信号的时域特征,     

Auditory steady-state response and auditory brainstem response thresholds in children

The inclusion of the auditory steady-state response (ASSR) into test-batteries for objective audiometry has allowed for clinical comparisons with the most widely used procedure, the auditory brainstem response (ABR). The current study describes ASSR and ABR thresholds for a group of infants and young children with various types and degrees of hearing loss. A sample of 48 subjects (23 female) with a mean age of 2.8 ± 1.9 years SD were assessed with a comprehensive test-battery and classified according to type and degree of hearing loss. Thresholds were determined with a broadband click-evoked ABR and single frequency ASSR evoked with continuous tones (0.25–4 kHz) amplitude modulated (67–95 Hz). Mean difference scores (±SD) between the ABR and high frequency ASSR thresholds were 9.8 (±11), 3.6 (±12) and 10.5 (±12) dB at 1, 2 and 4 kHz, respectively. An ASSR mean threshold for 2–4 and 1–4 kHz compared to the ABR threshold revealed an average difference of 7 (±9) and 7.9 (±8) dB, respectively. The overall correlation between the ABR and ASSR thresholds was highest for the mean ASSR thresholds of 2–4 and 1–4 kHz (r = 0.92 for both conditions). Correlations between the ABR and individual ASSR frequencies were slightly less (0.82–0.86). The average of the 2–4 kHz ASSR thresholds correlated best with the click-evoked ABR for all categories of hearing loss except for the sensorineural hearing loss category for which the 1–4 kHz ASSR average was better correlated to ABR thresholds. Findings demonstrate the reliability of verifying high frequency ASSR thresholds with a click-evoked ABR as an important cross-check in infants for whom behavioural audiometry may not be possible.     

Apical hair cell degeneration causes the increase in the amplitude of summating potential

Conclusion: This study indicates that the lesion of hair cells in the apical turn of the cochlea can cause the change in the summating potential (SP)/Compound potential (CAP) ratio.

Objectives: Electrocochleography is a valuable clinic test for diagnosis of cochlear pathologies and the ratio of SP to CAP has been used to identify Meniere’s disease. However, it remains controversial whether the increase of the SP/CAP ratio represents exclusively the endolymphatic hydrops.

Method: This study measured the SP and CAP in mice that displayed outer hair cell (OHC) degeneration in the apical section of the cochlea as their age increased.

Results: As compared with the mice aged 8–10 months, the 24-month old mice displayed a significant increase in the amplitude of SP at 12–16?kHz. This result suggests that the degeneration of OHCs in the apical turn leads to the increase of the?+?SP at the middle frequencies. In contrast, the aging mice did not have a significant change in the CAP amplitude at super-threshold levels.     

Changes in the organization of actin filaments in the stereocilia of noise-damaged lizard cochleae

Alligator lizards exposed to a 105 dB broadband noise for 24 h showed a 33 dB loss in hearing which was almost completely recovered 11 days after removal from the noise. Two lesions were found in the actin filament organization which could affect the rigidity of the stereocilia and thus could account for this hearing loss. These lesions preferentially affect the tallest stereocilia. The more common one is a depolymerization of the actin filaments at the base of the stereocilium where it makes contact with the cuticular plate. This results in a displacement and detachment of the stereocilium from its rootlet, thereby affecting the orientation of the tallest stereocilium. The other lesion involves a loss in crossbridges between adjacent actin filaments in the stereocilium. We demonstrate that such a loss will dramatically affect the rigidity of the stereocilia.