CT-Scanning of the cochlea in Pendred's syndrome*

The inner ears of 5 adult patients with Pendred's syndrome were investigated using a Siemens SOMATOM DRG. Five normal hearing adults participated in the investigation as a control group. The CT-scanning comprised 10-15 consecutive scans of the cochlea. The CT evaluation was performed using both a special bone setting and a soft tissue setting. The cochlear content was quantitatively evaluated by drawing an irregular region of interest on the bone pictures. The region of interest was then transferred to the soft tissue pictures by means of the standard program of the CT-scanner. The resulting mean values of attenuation expressed in Hounsfield Units were significantly lower in the Pendred cochleas was demonstrated in all patients with Pendred's syndrome. The lower values of attenuation of the cochlea in Pendred's syndrome reflect the rudimentarily developed infra-cochlear osseous structures in this disease. We conclude that CT-scanning of the cochlea using this procedure is reliable enough to replace the conventional axial-pyramidal tomography when a Mondini cochlea is suspected.     

小鼠耳蜗核因子-κB p50免疫组化定位

目的 了解核因子-κB(NF-κB)在耳蜗的表达情况.方法 小鼠皮下注射卡那霉素(KA),鼓室注射脂多糖(LPS),以注射等量生理盐水作为对照,用多克隆兔抗体NF-κB p50免疫组化染色,观察NF-κB p50在小鼠耳蜗的表达.结果 NF-κB p50主要定位在耳蜗的螺旋缘、盖膜、血管纹、螺旋韧带、螺旋神经节和神经纤维.整个耳蜗各圈均可观察到免疫反应,而螺旋韧带、盖膜、螺旋突、螺旋神经节和神经纤维均可观察到较强的免疫反应,Corti器的免疫反应比上述结构要弱一些.Corti器的内、外毛细胞,内、外柱细胞,Deiter细胞和Claudious细胞均可观察到NF-κB p50的免疫反应,这些免疫反应在内沟细胞、Hensen细胞和Claudious细胞较弱,而在螺旋神经节可观察到较强的免疫反应,内、外毛细胞核未见免疫反应.结论 注射脂多糖和卡那霉素可使NF-κB p50在小鼠耳蜗产生急性反应.     

豚鼠耳蜗Hensen细胞的分离、活性鉴定及其胞内静态游离Ca~(2+)分布

使用酶消化法及机械分离法对 Hensen细胞进行分离 ,置于倒置显微镜下用碘化丙啶及钙敏荧光染料 Fluo-3进行细胞活性鉴定并在激光扫描共聚焦显微镜下观察静息状态 Hensen细胞内的游离 Ca2 +的时空分布。结果证明 ,每个豚鼠耳蜗可以得到单离的 Hensen细胞 5～ 12个。细胞活性良好 ,可保持 5～ 6h。当细胞变性、坏死时可见一系列的形态学变化。对此得出几点判断 Hensen细胞活性的标准 :(1)细胞体呈卵圆形或椭圆形 ,大小可不一致 ;(2 )细胞膜完整 ,细胞边界清楚 ,折光现象明显 ;(3 )细胞浆清澈透明 ,无布朗运动 ,无溢出 ;(4 )细胞浆内的脂滴清晰可辨 ,折光现象明显 ;(5 )细胞无水肿 (即无气球样变 )。在静息状态下 ,Hensen细胞内的 Ca2 + 在细胞内分布不均匀 ,脂滴所在部位没有 Ca2 + 的分布。随时间延长 ,细胞内的 [Ca2 + ] i可小幅度振荡 ,但基本处于一种稳定状态。本工作为进一步对 Hensen细胞的其他特性进行研究打下了基础     

心钠素免疫反应在豚鼠耳蜗中的整体分布

目的 :研究豚鼠耳蜗中心钠素 (ANP)免疫反应的分布状态 ,为探讨ANP在耳蜗中的作用提供形态学基础。方法 :采用免疫组织化学ABC法检测ANP在正常豚鼠耳蜗各组织中的分布特征。结果 :在耳蜗 1～ 4回的血管纹、螺旋缘、Corti’s器、螺旋神经节和中间阶外壁的螺旋韧带均发现有ANP反应 (ANP IR)阳性产物 ;而耳蜗骨壁、前庭膜、鼓阶外壁的螺旋韧带和鼓阶的下壁ANP IR为阴性。结论 :耳蜗中的ANP在内耳淋巴液的生成和声信号的传导以及耳蜗血流量的调节等方面可能担负着重要的作用     

Dll3 is expressed in developing hair cells in the mammalian cochlea.

Notch mediates the process of lateral inhibition that controls the production of hair cells in the inner ear. Hair cells are known to express Notch ligands Dll1 and Jag2, which signal through Notch1 in adjacent supporting cells. However, recent genetic and pharmacological studies indicate that the level of Notch-mediated lateral inhibition is greater than can be accounted for by Dll1 and Jag2. Here, we report that another Notch ligand, Dll3, is expressed in developing hair cells, in a pattern that overlaps that of Dll1 and Jag2. We analyzed the cochleae of Dll3(pu) mutant mice, but did not detect any abnormalities. However, earlier studies have demonstrated that there is functional redundancy among Notch ligands in cochlear development and loss of one ligand can be at least partially compensated for by another. Thus Dll3 may play a role in lateral inhibition similar to that of Dll1 and Jag2.     

颞骨岩部结构的定位解剖及临床意义

目的:为颅底手术中耳蜗的定位、岩尖的磨除范围提供解剖学方法。方法:在12个成人头颅标本上利用颅中窝入路暴露岩内面神经、耳蜗、颈内动脉等结构。观测岩内膝状神经节、颈内动脉(internalcarotidartery,ICA)的膝部、内耳道内侧缘、棘孔与耳蜗之间的解剖关系。结果:耳蜗位于面神经膝状神经节的前下方和岩内ICA膝部的后上方,耳蜗覆盖到ICA膝部的上方。ICA水平段与ICA膝部和内耳道内侧缘连线的夹角为67.1°±4.3°。结论:以棘孔和膝状神经节连线的中点、膝状神经节、内耳道内侧缘形成的三角定位耳蜗。在耳前—颞下窝斜坡手术入路中,在中颅底,过ICA膝部做与ICA水平段成67.1°±4.3°的夹角,在这个夹角内磨除岩尖骨质,不会损伤耳蜗、内耳道及其内容物。耳蜗基底圈至ICA膝部的距离为(0.302±0.016)cm。从前向后磨除岩尖骨质时,ICA膝部后方的骨质磨除不要超过(0.302±0.016)cm,否则会损伤耳蜗。     

一氧化氮合酶在小鼠耳蜗的表达

目的：本实验用亲合免疫组织化学技术,研究了小鼠耳蜗内nNOS与eNOS的表达。方法：4％多聚甲醛心脏灌注固定后,取耳蜗、经脱钙,作10μm厚冰冻切片,进行nNOS和eNOS免疫组织化学染色,结果：小鼠耳蜗内、外毛细胸、内外柱细胞、螺旋神经节细胞nNOS、eNOS的表达呈强阳性。血管纹的基底和中间细胞、螺旋突起、螺旋韧带细胞处有阳性nNOS、eNOS的表达,耳蜗小球的内皮细胞无nNOS与的表达,但eNOS的表达呈阳性。结论：由nNOS和eNOS合成的NO在维持耳蜗正常神经传导及耳蜗正常血液供应中起着重要作用。     

铁缺乏对大鼠畸变产物耳声发射的影响

目的 观察铁缺乏大鼠畸变产物耳声发射（DPOAE）的一般特征及幅值变化,探讨铁缺乏对DPOAE的影响机制。方法 18只大鼠随机分为正常对照及实验组,缺铁饮食饲养法制备动物模型,实验及动物处死前检测DPOAE,并进行耳蜗肌动蛋白免疫组化检测,分析DPOAE变化及可能机制。结果 铁缺乏组大鼠20个测试耳中,12耳2．0kHz以上频率点的DPOAE幅值略有降低,耳蜗免疫组化检测显示其外毛细胞的肌动蛋白免疫组化无明显变化;另8耳2．0kHz以上频率点的幅值下降明显,尤以2．0kHz处为,相应的耳蜗免疫组化染色显示外毛细胞肌动蛋白免疫反应活性明显降低。结论 铁缺乏可影响DPOAE幅值,其机制可能与耳蜗听毛细胞肌动蛋白免疫反应活性降低及组织缺氧有关。     

Direct current pulse elicits basilar membrane vibration in guinea pigs

Since the lagos, the elec~lity of the cochleahas attheted much attention. It has been demonshatedthat the outer air cells (OHCs) Play a key role in theeleC~hty of the COChiea. EvanS et al if] found thatthe OHCs exhiliited in cairo length change in a Voltagedependent manner upon electric stimulation, applying thatOHCs assess electIO~mecbocal ~sduchon ability,which motivates the intwry into the causality betWeenOHC electIDmotility and basilar membrane (BM) vibrationand fulther, into th…