Study of mechanism of development in to the pars tensa cholesteatoma and sensory neural hearing loss in adhesive otitis media

动物实验：封闭耳咽管鼓室口，损伤中耳腔粘膜组出现鼓室粘连。有些动物的鼓膜粘连是由于肉芽形成的结果，而另一些动物的鼓膜粘连是薄的。发现中耳粘膜气体交换功能受损，以及咽鼓管通气不良是造成鼓室粘连的重要因素。分子生物学研究：采用原位杂交方法，以粘连性中耳炎不同组织为研究对象，研究表皮生长因子（Epidermal growth factor， EGF）、表皮生长因子受体（EGF- r）和受体为EGF- r的转化生长因子（transforming growth factor， TGF） mRNA的定位。炎性肉芽肿型上皮下可见炎性细胞浸润，EGF表达与胆脂瘤相似，EGF- r、TGF表达也较强。在纤维性肉芽和透明化型中，上皮下层炎症细胞缺失，未见EGF表达，EGF- r和TGF表达较弱。这些结果提示，当上皮下层发生活动性病理改变时，可能进一步促进表皮增生，形成胆脂瘤。中耳腔气体交换功能：观察粘连性中耳炎术后中耳压力及中耳腔气体交换功能。随着中耳粘膜的改善，中耳腔压力有增加的趋势，中耳腔的产气功能恢复。然而，在广泛切除鼓室粘膜的患者中，由于中耳黏膜上皮化的延迟，中耳腔压力的增加往往较差。咽鼓管功能：术后主要基于声学方法研究咽鼓管功能。许多患者术前术后声学测试均呈阳性。打开/关闭咽鼓管的时间不同，从100毫秒到6000毫秒不等。术前和术后的数值比较，没有发现明确的趋势。对于术后鼓膜再粘连的患者，术前咽鼓管部分狭窄，部分正常，因此术前咽鼓管功能难以准确预后。少

Animal study : Tympanic adhesion was observed in a group in which the tympanic opening of the eustachian tube had been closed and the mucosa of the middle ear cavity had been damaged. Tympanic adhesion occurred as a result of granulation in some snimals, while adhesion of a thin tympanic membrane was seen in other animals. It was found that impaired gas exchange function of the middle ear mucosa, as well as poor ventilation of the eustachian tube, is an important factor of tympanic adhesion.Molecular biological study : Epidermal growth factor (EGF), EGF receptor (EGF-R), and transforming growth factor (TGF) whose receptor is EGF-R were studied with respect to localization of their mRNA by in situ hybridization method employing various tissues of adhesive otitis media. In the inflammatory granulation type, in which subepithelial inflammatory cell infiltration is seen, expression of EGF was similar to that seen with cholesteatoma, and expression of EGF-R and TGF was also strong. In fibro … More us granulation and hyalinization types, in which subepithelial layr inflammatory cells are absent, expression of EGF was not seen, and expression of EGF-R and TGF was weak. These findings suggest that, when there is active pathological changes in the subepithelial layr, epidermal proliferation may be further promoted, and cholesteatoma may be developed.Gas exchange function of middle ear cavity : Middle ear pressure and gas exchange function of the middle ear cavity were examined after operation for adhesive otitis media. As middle ear mecosa improved, middle ear cavity pressure tended to increase, and gas-generating function of the middle ear cavity recovered. However, in patients undergoing extensive removal of tympanic mucosa, increase in the pressure of the middle ear cavity tended to be poor because of delayd epithelization of middle ear mucosa.Eustachian tube function : Postoperative function of the eustachian tube was studied mainly based on the acoustic method. Many patients tested positive fot the acoustic test both before and after operation. Duration of time of open/closure of the eustachian tube differed, ranging from 100 msec to 6000 msec. When pre- and post-operative values were compared, no definite tendency was detected. In patients exhibiting re-adhesion of tympanic membrane postoperatively, preoperative eustachian tube was narrow in some cases, but it was normal in others, Hence, it is difficult to make accurate prognosis based on pre-operative eustachian tube function. Less