一个遗传性非综合征型耳聋家系的突变分析

目的分析一个遗传性非综合征型耳聋家系的突变，并探讨缝隙连接蛋白beta2(gap junction protein beta 2，GJB2)基因235delC突变是否会加重线粒体A1555G突变导致的非综合征型耳聋症状。方法对一个母系遗传性非综合征型耳聋核心家系72个成员取外周血提取DNA，经聚合酶链反应扩增后，利用Alw26Ⅰ限制性内切酶酶切及直接测序验证，对其线粒体DNA突变进行研究；利用ApaⅠ限制性内切酶酶切及直接测序验证，筛查核心家系中GJB2基因235delC突变情况，并对GJB2基因235delC和线粒体A1555G突变的关系进行研究。结果在27名母系成员中均发现具有线粒体A1555G突变，呈母系遗传；具有耳聋表型的为21人(77．8％)，家族外显率高；所筛查的包括配偶在内的72名个体中，仅3例具有GJB2基因235delC杂合子突变，且均出现在母系成员中，但3例的耳聋表型却不同。结论线粒体A1555G突变是本家系耳聋遗传易感性的基础，在该家系中GJB2基因的235delC杂合子突变未加重线粒体A1555G突变导致的非综合征型耳聋。     

A novel locus for autosomal dominant nonsyndromic hearing loss identified at 5q31.1-32 in a Chinese pedigree

 Hearing impairment is an extremely heterogeneous disorder. A total of 35 loci and 17 related genes for autosomal dominant nonsyndromic hearing loss have been identified. In a Chinese pedigree characterized by autosomal dominant inheritance with bilateral, postlingual, progressive, and sensorineural nonsyndromic hearing impairment, the putative disease gene locus was localized to chromosome 5q31.1-32 by a genome-wide scan. Fine mapping indicated that the disease gene was located within an 8.8-cM region between markers D5S2056 and D5S638, with a maximum two-point logarithm of differences (LOD) score of 6.89 (θ = 0) at D5S2017. By the candidate gene approach, mutation screening of the DIAPH1 and POU4F3 genes at 5q31 was performed. No mutation was found, suggesting that this is a novel deafness locus, which has been named DFNA42. Received: May 8, 2002 / Accepted: October 1, 2002     

Processing of binaural stimuli by cat superior olivary complex neurons

Summary A method was developed to record stereotactically from the cat Superior Olivary Complex (SOC) using glass micropipettes. Sound stimulation was given through a closed system that permitted independent variation of interaural time (time) and intensity (int) differences. The most common binaural units found (n = 34) were ipsilateral excitatory, contralateral inhibitory (EI¹), cells of the Lateral Superior Olive (LSO). Some Medial Superior Olive (MSO) cells and presumed MSO ascending afferents were found but, as noted by other authors, we found it difficult to obtain single unit recordings from this nucleus. The LSO EI cells were mostly sensitive to higher frequencies and showed Peristimulus Time Histograms (PSTHs) consisting of a sharp On response followed by a plateau when stimulated with Best Frequency (BF) tone bursts or noise bursts. This On response was sensitive to time and int such that ipsilateral time lead or intensity increase resulted in a stronger response. The response reached a minimum around zero time or int. No sharp peaks or dips were seen in the physiological range needed for localization, instead the response increased with increasing ipsilateral lead or intensity to the maximum values tested (2048 s time, 30 dB int). In the physiological range the time and int response were complementary (both increasing response as ipsilaterality was increased). Provided enough sound energy in the unit's sensitive region was present, the same time curves were produced when BF tone bursts, masked tone bursts, sharp onset tone bursts or noise bursts were used. Changing the time of the carrier of the tone burst alone had no effect (except for one cell with a BF of 560 Hz), only the relative time of arrival of the stimulus envelope seemed to be important. In contrast to these LSO EI cells MSO-type units showed EI or EE predominantly low frequency phase-locked responses. When stimulated with interaurally phase shifted (pha) BF tones the unit response was a cyclic function of pha. Some cells (all that were tested, n = 6 including the 560 Hz LSO EI cell) showed these cyclic responses when stimulated with noise bursts or non-BF tones. However, these characteristic delays were not necessarily in the physiological range, i.e. we could find no evidence that these units were responding to time/pha values corresponding to a particular sound source direction. In both LSO and MSO it seems that integration of information higher in the CNS from a population of these cells is necessary for unambiguous coding of sound source direction. The time intensity trading ratios measured in two MSO type cells (11 and 26 /dB) were clearly different to those measured in LSO EI cells (n = 6, 99–550 s/dB). These ratios correspond approximately to those of the psychophysical time and int images measured by Hafter and Jeffress (1968).Supported by the Deutsche Forschungsgemeinschaft (SFB 45)     

Eccentric visual acuity in patients with macular disease

A series of cards each containing a two dimensional array of identical Snellen "E's" was used to determine best eccentric visual acuity in patients with macular disease having Snellen visual acuity of 20/70 or worse. Each "full field E" card simultaneously presents the same letter to foveal and parafoveal areas. This test can therefore determine quickly if potentially useful vision is present in any area of the central visual field. In our study of 37 eyes, 70% demonstrated potential visual acuity at least two times better than visual acuity measured by conventional methods, and 20% demonstrated at least a fourfold improvement. This suggests that most patients with macular disease do not spontaneously employ their best remaining area of retina for fixation.     

上海市青浦区噪声作业人员听力状况分析

目的 了解近3年青浦区噪声作业人员的听力变化趋势,为预防职业性噪声聋提供依据。方法 收集2018-2020年青浦区噪声作业人员在岗期间的听力数据,并运用SPSS软件进行统计分析。结果 噪声作业人员的双耳高频平均听阈升高率2018-2020年分别为6.09%、5.16%、3.06%,呈逐年降低趋势(P<0.01);男性升高率高于女性(P<0.01);随着年龄、工龄的增加,升高率呈现增高趋势(P<0.01)。双耳高频平均听阈升高率位于前三的行业分别为建筑业(28.57%)、租赁和商务服务业(18.72%)以及批发零售业(13.89%)。结论 噪声作业人员的职业病防控工作仍不可放松,应及时对噪声作业重点人员进行有针对性的干预。     

腭裂患儿鼓膜象及听力损失的调查

目的 :了解腭裂患儿中耳功能障碍及听力损失的发病情况。方法 :对腭裂患儿及正常儿童各 5 0例进行电耳镜检查 ,对部分能够合作患儿及正常儿童行纯音测听。结果 :腭裂患儿鼓膜异常像及听力损失发生率分别达74%及 5 8% ,对照组分别为 2 9%及 12 % ,二者有显著性差异 (P <0 0 1)。结论 :腭裂患儿应定期进行耳镜及听力检查 ,及时处理中耳疾患 ,以免严重听力损害的发生 ,对防聋治聋很有意义。     

Selective labeling of sensory hair cells and neurons in auditory, vestibular, and lateral line systems by a monoclonal antibody

This study reports that zn-1, a monoclonal antibody, labels hair cells but not supporting cells in the inner ear and the lateral line of the axolotl salamander, Ambystoma mexicanum. Zn-1 immunocytochemically labels the cytoplasm and stereocilia of mature hair cells in the sacculus, in the utriculus, and in the mechanoreceptive neuromast organs of the lateral line. Lower levels of labeling mark newly formed hair cells in the periphery of the sacculus and in regenerating neuromasts. Zn-1 also selectively labels neuronal processes and perikarya in the lateral line nerves and ganglia and the VIIIth cranial nerve and ganglion. Processes and perikarya are labeled by zn-1 in the dorsolateral medulla oblongata, at sites of termination of the afferent octaval and lateral line neurons. Western blot analysis revealed that zn-1 labels one or more proteins with molecular weights of 80 and 160 kDa. The identity of these protein bands remains to be determined. The presence of a specific epitope expressed in both hair cells and neurons, but not in supporting cells, in the vestibular and auditory epithelia of the ear and in the mechanoreceptive neuromasts of the lateral line suggests shared cytogenetic heritages. These findings are consistent with a close evolutionary relationship between otic and lateral line senses, such as that inherent to the theoretical evolutionary scheme outlined in van Bergeijk's "acousticolateralis hypothesis." The protein recognized by zn-1 is as yet unidentified, but its conservative evolution suggests that it may serve an important function in the statoacoustic and lateral line systems.     

王不留行治疗突发性耳聋的临床和实验研究

本研究共收集突发性耳聋病人６２例,其中王不留行治疗组３２例,取得较好疗效,总有效率为７５．０１％（痊愈６．２５％、显效２１．８６％、好转４６．９％）,与对照组（丹参注射液治疗组）相比无显著性差异（Ｐ〉０．０５）。本病疗效与病人年龄、病程等因素关系十分密切,老年人,特别是在５０岁以上的病人、病程长者疗效较差。为进一步验证王不留行的临床疗效,我们运用豚鼠静脉注射高分子右旋糖酐造成血瘀模型,检测耳蜗电位     

Heparin-induced extracorporal low-density-lipoprotein precipitation (H. E. L. P.) to improve the recovery of hearing in patients with sudden idiopathic hearing loss

The pathogenesis of sudden hearing loss (SHL) is still not well understood. Possible causes include increased blood viscosity, microthrombosis or altered blood flow. Hypercholesterolemia, hyperfibrinogenemia and increased platelet aggregation are frequently observed in patients with SHL. The aim of this study was to investigate whether drastic lowering of plasma cholesterol and fibrinogen by selective extracorporal apheresis could have a beneficial effect on hearing recovery in these patients. Seven patients with SHL were treated with an extracorporal procedure removing fibrinogen and cholesterol from plasma. Six of the seven patients showed an immediate improvement in auditory thresholds following a single treatment of heparin-induced low-density lipoprotein precipitation. These findings indicate for the first time that acute and drastic removal of plasma fibrinogen and low-density lipoproteins may be an effective clinical method for the treatment of patients with SHL. Received: 19 February 1999 / Accepted: 6 May 1999     

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.