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.     

盐酸山莨菪碱对噪声暴露后耳蜗琥珀酸脱氢酶活性的影响

目的：观测豚鼠在噪声暴露后不同时间内盐酸山莨菪碱（６５４－２０防治组和损伤组的耳蜗琥珀酸脱氢酶（ＳＤＨ）活性变化,探讨噪声暴露后ＳＤＨ活性的变化趋势以及６５４－２在噪声暴露中对ＳＤＨ活性的影响。方法：把豚鼠分成对照组、损伤组与６５４－２防治组,在噪声暴露后不同时期,用Ｎａｃｈｌａｓ四唑氮盐法及图象分析仪显示并测算ＳＤＨ活性。结果：在噪声暴露后第３天,各组酶活性损伤最重。各组耳蜗ＳＤＨ活性第１、２回     

Ear anomalies and hearing loss in patients with VACTERL association and the effect of maternal diabetes

VACTERL association is typically defined as the presence of three components among these birth defects: vertebral anomalies, anal atresia, cardiac anomalies, esophageal atresia/tracheoesophageal fistula (EA/TEF), renal anomalies, and limb defects. There is increasing recognition that VACTERL and other recurrent constellations of embryonic development often overlap clinically and might share pathogenesis. We conducted a comprehensive chart review of a large patient population with VACTERL association from two tertiary care centers in California. We included patients with incomplete VACTERL expression, which we denoted as “partial VACTERL” (pVACTERL). We assessed the occurrence of craniofacial (CF) findings in these two groups and the combined cohort. We collected data on potential risk factors and demographic information such as sex, Hispanic ancestry, pregnancy complications, and maternal age. The study included 409 participants, of whom 263 had VACTERL and 146 pVACTERL. CF abnormalities were found in 17.3% of VACTERL patients and 9.4% of pVACTERL patients. In the VACTERL group, ear anomalies were found in 10.2%, microtia in 5.9%, hearing loss (HL) in 13.90%, and orofacial clefts in 3.1%. In the pVACTERL group, ear anomalies were found in 7.2%, microtia in 5.0%, HL in 9.3%, and orofacial cleft in 2.2%. Maternal diabetes significantly increased the risk for HL in VACTERL (odds ratio [OR]: 3.71, 95% confidence interval [CI]: 1.5–7.3) and pVACTERL patients (OR: 6.7, 95% CI: 1.70–23.4). Poorly controlled maternal diabetes significantly increased the risk for all the outcomes in VACTERL patients including CF anomalies (OR: 4.2, 95% CI: 1.9–9.6), ear anomalies (OR: 4.7, 95% CI: 1.8–11.8), microtia (OR: 5.4, 95% CI: 1.7–16.6), and HL (OR: 8.1, 95% CI: 3.4–19.4). Twin status was significantly associated with the occurrence of microtia (p = 0.038) in VACTERL patients. Occurrence of CF features, particularly ear anomalies, microtia, and HL, might be considered as part of phenotypic diversity of VACTERL association. Diabetes and twinning might appear to play a role in increasing the risk for this phenotype in VACTERL association.     

Synaptic connections of the auditory nerve in cats: relationship between endbulbs of held and spherical bushy cells

This report focuses on a class of large synaptic endings, the endbulbs of Held. These endings are located in the anteroventral cochlear nucleus and arise from the axons of type I spiral ganglion neurons. Axons were stained with horseradish peroxidase (HRP) using intracellular injections of single fibers or extracellular injections into the auditory nerve. Individual endbulbs or pairs of endbulbs that converged onto the same spherical bushy cell were examined with the aid of a light microscope and subjected to morphometric analyses. Endbulbs of fibers having low spontaneous discharge rates (SR, less than or equal to 18 spikes/sec) have a more complex shape than those of high SR fibers (greater than 18 s/s), a feature represented by systematic differences in endbulb silhouette perimeter without differences in endbulb silhouette area. Consequently, the ratio, silhouette area divided by silhouette perimeter, yields a "form factor" separating endbulbs of high SR from those of low SR. High SR fibers had ratios greater than 0.52 (mean = 0.63 +/- 0.09), whereas low SR fibers had ratios less than 0.52 (mean = 0.45 +/- 0.06). Pairs of endbulbs with unknown physiological properties had similar form factor values, despite the wide range of values observed in the endbulb population. These data imply that endbulbs converging upon the cell body of a spherical bushy cell arise from fibers of the same SR group. Electron microscopic examination was conducted on the endbulb of one physiologically characterized and intracellularly stained auditory nerve fiber (CF = 1.4 kHz; SR = 55 s/s) and its unstained endbulb mate with the aid of serial ultrathin sections. In addition to the well-known axosomatic synapses, these endbulbs formed axodendritic synapses: 11.7% for the HRP-labeled endbulb and 13.3% for the unlabeled endbulb. The axodendritic synapses appear to occur on dendrites of nearby spherical bushy cells and may represent a mechanism whereby single endbulbs can disperse activity to multiple neurons in the cochlear nucleus. We propose that axosomatic synapses preserve fiber SR groupings, whereas axodendritic synapses may not.     

Acid maltase deficiency in non-identical adult twins

Summary Acid maltase deficiency is described in non-identical adult twins. The onset of the disease can be traced into late infancy; the clinical picture is one of severe muscular dystrophy; respiratory insuficiency was the cause of death in one case. The autopsy showed the central nervous system, heart and liver to be spared. Glycogen filled vacuoles are found in skin, mesenchymal cells, small nerves and skeletal muscles. The light microscopic study of 9 different muscles showed extremely variable involvement ranging from normal appearance to overt vacuolization. A 6–20% residual acid -glucosidase activity was found in visceral organs, cultured fibroblasts and in some skeletal muscles. No satisfactory explanation can be given why this generalized acid -glucosidase deficiency produces a selective involvement of skeletal muscles. If compared with infantile AMD (Pompe's disease) our cases have a much higher residual acid -glucosidase activity and show the presence of an antigenically detectable protein.From our study and from a similar report in the literature (de Barsy et al., 1975), it appears that a combined approach of light microscopy, electron microscopy and biochemical analysis (determination of acid -glucosidase) is necessary to make a diagnosis of AMD in adults.Dr. Th. de Barsy is a Research Fellow of the Fonds National de la Recherche Scientifique.     

内耳畸形患儿的人工耳蜗植入

目的：探讨几种内耳畸形患儿的人工耳蜗植入效果。方法：对10例内耳结构异常的感音性耳聋患儿进行了人工耳蜗植入。结果：术后随访0．5～4．0年，10例基本达到了较满意的听觉言语恢复效果。结论：内耳畸形息儿行人工耳蜗植入，应严格进行术前听力学与影像学的评估，严格掌握手术的适应证，可以达到较满意效果。     

Unusual presentation of a giant glomus tumor

Giant glomus tumors pose a challenge to the Otologist by virtue of their location and vascularity. A vast majority of them present with tinnitus, conductive hearing loss and cranial nerve palsies. We report the case of a 16-year-old male patient who presented with sudden right-sided sensorineural hearing loss. This is an unusual presentation of a giant glomus tumor. We present the clinical features and management of this unusual case.