豚鼠分泌性中耳炎模型的建立

目的 建立豚鼠分泌性中耳炎的动物模型。方法 20只豚鼠均分为对照组和造模组,造模组将0.1ml灭活的肺炎链球菌悬浮液注入豚鼠的鼓室内,5天后耳内窥镜下观察鼓室积液情况,检测反应阈,了解光镜下咽鼓管的组织形态变化。结果 20耳中有14耳出现鼓室积液,光锥消失。反应阈由14.00±3.08dB提高至45.00±5.67dB,光镜下咽鼓管的黏膜面有无结构的红染物覆盖,杯状细胞增多,胞质及胞核深染。结论 灭活的肺炎链球菌悬浮液注入豚鼠的鼓室内制造豚鼠分泌性中耳炎的动物模型切实可行。     

肺表面活性物质治疗豚鼠分泌性中耳炎前后咽鼓管的组织形态学变化

目的　研究肺表面活性物质对分泌性中耳炎的治疗作用 ,为分泌性中耳炎的治疗探索新的途径。方法　采用灭活的肺炎链球菌鼓室内注射 ,建立豚鼠分泌性中耳炎的动物模型 ,鼓室内注射肺表面活性物质 1周后检测听性脑干反应 (auditorybrainstemresponse ,ABR)反应阈的变化 ,观察肺表面活性物质治疗前后咽鼓管黏膜光镜和电镜下的组织形态学变化。结果　豚鼠鼓室内注射灭活肺炎链球菌悬浮液 5d后 :鼓室积液 ,鼓膜浑浊 ,光锥消失 ,ABR平均 ( x±s)反应阈由正常对照组的 (14 0± 3 1)dB提高至 (45 0± 5 7)dB ;豚鼠咽鼓管黏膜层增厚 ,黏膜面有无结构的红染物覆盖 ,纤毛排列紊乱。经肺表面活性物质治疗 1周后 :鼓室积液减少或消失 ,ABR平均反应阈由 (45 0± 5 7)dB降低为(2 3 5± 6 3)dB。t检验分析 ,造模组与肺表面活性物质治疗组反应阈差异有极显著性 (P <0 0 0 1) ;豚鼠咽鼓管黏膜层变薄 ,纤毛排列较整齐 ,朝向鼻咽侧。结论　肺表面活性物质对豚鼠分泌性中耳炎有治疗作用。     

儿童分泌性中耳炎的听力学分析

目的 分析儿童分泌性中耳炎的听力学特征,探讨不同听力学测试方法在儿童分泌性中耳炎诊断中的作用和准确性,为儿童分泌性中耳炎的诊断提供理论依据.方法 回顾性分析2010年1月～2011年6月诊断为分泌性中耳炎住院治疗的46例(81耳)患儿的资料.所有患儿均行中耳鼓膜切开,将声导抗、畸变产物耳声发射(DPOAE)、听性脑干反应(ABR)、纯音测听(pure tone audiometry,PTA)结果与术中所见进行比较分析,了解不同听力学测试方法在评估儿童分泌性中耳炎中的作用和准确性.结果 ①46例(81耳)患儿的DPOAE检查结果均提示双耳未通过,声导抗检查均为B型导抗图.鼓膜切开证实70耳有分泌物(86.42%),11耳无明显分泌物(13.58%).②34例(59耳)行ABR测试的患儿,鼓膜切开证实49耳(83.05%)有积液,其中6耳ABR反应阈正常,43耳ABR反应阈升高;46耳ABRⅠ波潜伏期延长,3耳Ⅰ波潜伏期正常.鼓膜切开证实无积液的10耳(16.95%),5耳ABR反应阈正常,5耳ABR反应阈升高;4耳ABRⅠ波潜伏期延长,6耳Ⅰ波潜伏期正常.③12例(22耳)行PTA测试的患儿,所有耳的听阈值均异常,气骨导差均大于10 dB,鼓膜切开证实22耳均有积液.④统计学分析结果显示,ABR气导反应阈值(Kappa=0.364,P<0.01)、Ⅰ波潜伏期(Kappa=0.561,P<0.01)与中耳积液有相关性.结论 声导抗测试对评估儿童分泌性中耳炎有较高的敏感性,PTA气导听阈及气骨导差、ABR气导反应阈值、ABRⅠ波潜伏期及DPOAE亦可较好地反映儿童中耳功能.     

庆大霉素鼓室内注射对耳蜗的毒性及刺五加的保护作用-听觉电生理研究及电镜观察

目的:采用庆大霉素鼓室内注射,通过听觉电生理研究及电镜观察,研究豚鼠中耳局部应用庆大霉素的耳蜗毒性作用,以及刺五加有无对抗庆大霉素耳毒性作用。方法:选择健康豚鼠44只,随机分成3组:庆大霉素组、庆大霉素和刺五加组、生理盐水组。分别检测3组豚鼠ABR。鼓室内注射每天1次,连续7天:第1、2组注射3%庆大霉素,第3组注射生理盐水。第2组同时腹腔注射刺五加注射液,每天1次,连续14天。2周后检测3组ABR反应阈。处死,制备标本行电镜观察。结果:第1组ABR反应阈于给药前、后分别为20.63±6.55dbSpl、69.69±18.02dbSpl;第2组分别为18.75±5dbSpl、40.33±16.53dbSpl;第3组分别为19.17±4.69dbSPI、23.75±8.53dbSpl。单因素方差分析(ANOVA),给药前3组ABR反应阈差异(F=0.5,P>0.05)无统计学意义;给药前、后3组ABR反应阈差异(F=24.31,P<0.01)有统计学意义。给药前、后各组ABR反应阈之差(配对t检验),第1和第2组有统计学意义,第3组无统计学意义。给药前、后3组ABR反应阈之差两两比较(scheffe检验),第1组和第2组、第1组和第3组、第2组和第3组均有统计学意义。扫描电镜第1组,可见corti器外毛细胞纤毛稀疏、脱落及破坏,内毛细胞基本正常;第2组可见外行细胞纤毛倒伏、变形及模糊,内毛细胞正常;第3组可见耳蜗内、外行细胞均正常。透射电镜第1组可见corti器毛细胞核染色质固缩、凝聚,线粒体嵴断裂,空泡样变性;第2组毛细胞线粒体肿胀,嵴模糊,部分断裂;第3组毛细胞正常。结论:豚鼠鼓室内注射庆大霉素可以导致耳蜗corti器毛细胞破坏,ABR反应阈显著提高,具有明显的耳蜗毒性。联合应用中药刺五加组的豚鼠也出现了耳蜗corti器毛细胞破坏,ABR反应阈提高,但比单独应用庆大霉素组程度轻,表明刺五加具有对抗庆大霉素耳毒性作用。提示临床应禁用庆大霉素溶液滴耳,并可采用中药刺五加治疗药物性耳聋。     

婴儿1 000 Hz探测音鼓室导抗测试结果分析

目的 探讨婴儿1 000 Hz探测音鼓室导抗测试结果的分型及各型对婴儿中耳功能的评估价值.方法 对89例(178耳)年龄4～26周的婴儿分别行226、1 000 Hz探测音声导抗、ABR及DPOAE测试,并对1 000Hz探测音鼓室导抗图结果分型;分别比较各型的226 Hz探测音声导纳峰值压力、静态声导纳、鼓室导抗图宽度、ABR的波Ⅰ潜伏期、反应阈及DPOAE的通过率.结果 ①178耳根据1 000 Hz探测音鼓室导抗图分为正峰型(Ⅰ组)89耳、平坦型(Ⅱ组)64耳、其它型(Ⅲ组)25耳;②Ⅰ组的ABR波Ⅰ潜伏期(1.2±0.1 ms)、反应阈(21±6dB nHL)均正常,DPOAE通过率为100%;Ⅱ组和Ⅲ组的ABR的波Ⅰ潜伏期较Ⅰ组延长,分别为1.8±0.4、1.3±0.2 ms,反应阈分别为36±13、25±8 dB nHL,两组中波Ⅰ潜伏期和反应阈均正常者分别为4.69%(3/64)和40.0%(10/25),DPOAE的通过率分别为3.1%和44.0%;③226 Hz探测音鼓室导抗图峰值压力Ⅰ组高于Ⅱ组,差异有显著统计学意义(P＜0.01),在Ⅰ组和Ⅲ组间、Ⅱ组和Ⅲ组间差异无统计学意义(P＞0.05);226 Hz探测音静态声导纳、鼓室导抗图宽度及分型在三组间差异均无统计学意义(P＞0.05).结论 婴儿的1 000 Hz探测音鼓室导抗图正峰型为正常,平坦型及其它型为异常,且鼓室导抗图为平坦型时中耳功能最差.1 000 Hz探测音声导抗测试对婴儿中耳功能的诊断价值比ABR的波Ⅰ潜伏期和耳声发射的敏感性更高.226 Hz探测音声导抗测试不适用于判断婴儿中耳功能状态.     

听性脑干反应（ABR）测试在儿童分泌性中耳炎诊治中的作用

目的探讨听性脑干反应（auditory brainstem response,ABR）测试在1岁6个月～6岁的儿童分泌性中耳炎诊治中的应用价值。方法①在首诊时采用ABR测试97例179耳1岁6个月～6岁的分泌性中耳炎患儿,根据反应阈提高的程度分为3组：轻度组为20～30dB nHL,中度组为40～60dB nHL;重度组为70～90dB nHL。以同一年龄段的正常小儿为对照组,分析4组ABR波潜伏期和波间期的特点。②选择轻,中度组病例各10例（20耳）、重度组5例（10耳）,行鼓膜穿刺或鼓膜切开术,分析中耳积液量和性状与ABR波潜伏期的关系。③随诊治疗中,每周检测ABR一次,以监测疗效,并以对照组ABR潜伏期和反应阈为指标判断预后。结果①轻、中、重度3组随着ABR反应阈的提高,Ⅰ、Ⅲ、Ⅴ波潜伏期延长增多,而波间期无明显变化。②轻、中度组随着中耳积液的增多变稠,ABR的Ⅰ、Ⅲ、Ⅴ波潜伏期延长增多。重度组中耳积液与中度组无明显差异,而Ⅰ、Ⅲ、Ⅴ波潜伏期延长却明显增加。③轻、中、重度3组预后不同。结论在分泌性中耳炎的诊治中,声导抗测试虽能为中耳病变提供重要依据,但辅以ABR测试,不仅能提供更多的中耳信息,还能反映内耳功能和高频听觉状态,作为该病诊断以及判断疗效和预后的依据。     

婴儿分泌性中耳炎的听力学结果分析

目的 探讨226、1 000 Hz鼓室声导抗测试和气-骨导听性脑干反应（ABR）以及畸变产物耳声发射（DPOAE）在诊断低月龄婴儿分泌性中耳炎（OME）中的作用。方法 回顾性分析年龄为1～6个月的119例（192耳）中耳积液患儿（异常组）和66例（132耳）正常婴儿（正常组）的226、1 000 Hz鼓室声导抗测试和气-骨导ABR,以及DPOAE检测结果。结果 （1）OME婴儿,1 000 Hz鼓室声导抗异常图形（As型、B型、C型）有189耳（98.44%）,226 Hz鼓室声导抗异常图形（As型、B型、C型）有135耳（70.31%）;(2)OME婴儿ABR波Ⅰ潜伏期延长179耳（93.23%）,ABR波Ⅴ反应阈中度异常69耳（35.94%）、轻度异常97耳（50.52%）、阈值正常26耳（13.54%）,骨导ABR阈值正常164耳（85.42%）,阈值轻度异常28耳（14.58%）,气-骨导ABR阈值差值变大162耳（84.37%）;(3)OME婴儿DPOAE未引出151耳（78.65%）。结论 1 000 Hz声导抗异常、气-骨导ABR阈值差变大、ABR波I潜伏期延长和气导AB...     

耳内镜下鼓膜置管术治疗分泌性中耳炎

分泌性中耳炎(otitis media with effusion.OME)是以鼓室积液及传导性耳聋为主要特征的中耳非化脓性炎性疾病.对于反复发作、保守治疗无效的分泌性中耳炎患者,鼓膜切开置管术是有效治疗方法,我科2006年6月-2007年5月在耳内镜下行鼓膜置管术42例(75耳),取得良好疗效.报道如下.     

1～6岁分泌性中耳炎患儿气、骨导ABR的特征分析

目的探讨气、骨导ABR测试在儿童分泌性中耳炎诊疗中的应用价值。方法回顾性分析151例(246耳)分泌性中耳炎(OME组)和60例(120耳)正常儿童(正常对照组)气、骨导ABR检测结果。结果①OME组气导ABR波V反应阈正常59耳(23.98%),轻度异常96耳(39.02%),中度异常91耳(36.99%);ABR波Ⅰ、Ⅲ、Ⅴ潜伏期正常22耳(8.94%),各波潜伏期延长224耳(91.06%),Ⅰ-Ⅴ波间期无明显改变156耳(63.41%),Ⅰ-Ⅴ波间期缩短90耳(36.59%);波Ⅴ反应阈正常和轻度异常组Ⅰ-Ⅴ波间期无明显改变,中度异常组Ⅰ-Ⅴ波间期缩短,差异有统计学意义(P<0.05)。②OME组骨导ABR波V反应阈及35dB nHL刺激强度下各波潜伏期与对照组比较,反应阈正常195耳(79.27%),异常51耳(20.73%),反应阈异常者波Ⅰ、Ⅲ、Ⅴ潜伏期也较正常组及反应阈正常者明显延长(P<0.05)。结论大多数分泌性中耳炎儿童的气导ABR反应阈轻、中度异常但骨导ABR反应阈正常,少数患儿气导ABR反应阈中度异常且骨导ABR反应阈轻度异常。     

DPOAE异常ABR反应阈正常的婴儿声导抗结果分析

目的分析DPOAE异常ABR反应阈正常婴儿声导抗特征。方法研究对象为34例(52耳)婴儿(研究组),年龄42天～10个月,男20例(33耳),女14例(19耳),均为外院听力筛查未通过,转诊后经听性脑干反应(ABR)、畸变产物耳声发射(DPOAE)、声导抗(226和1 000Hz探测音)测试,表现为DPOAE全频异常、ABR反应阈正常。选取同期接受检查且DPOAE及ABR反应阈均正常的婴儿26例(52耳)作为对照组,年龄42天～10个月,男16例(32耳),女10例(20耳),对比分析两组对象的声导抗特征。结果对照组226Hz鼓室导抗图48耳为单峰,4耳为双峰;1 000Hz鼓室导抗图50耳为单峰,2耳为双峰。根据ABR检测结果将研究组分为三组:第一组24耳ABR反应阈及各波潜伏期均正常,226Hz鼓室导抗图21耳为A型,3耳为双峰,1 000Hz鼓室导抗图18耳为单峰,6耳为双峰,其负尾部补偿导纳(ComY-400)值为0.84±0.36,低于对照组(2.66±0.52)(P<0.05);第二组23耳ABR波I潜伏期延长,波III、V潜伏期延长或不延长,226Hz鼓室导抗图18耳为A型,2耳为B型,3耳为双峰,1 000Hz鼓室导抗图15耳为单峰,2耳为双峰,2耳为无峰,4耳为其他型,其ComY-400值为0.54±0.37,低于对照组(2.66±0.52)(P<0.05);第三组5耳仅ABR波V潜伏期延长,226Hz及1 000Hz鼓室导抗图均表现为单峰。结论 DPOAE异常而ABR反应阈正常的婴儿可表现为ABR各波潜伏期正常或异常,l 000Hz探测音鼓室导抗图表现为负尾部补偿导纳值低于正常婴儿,提示其中耳功能异常可能是导致DPOAE异常的主要原因。     

Histo-morphological changes of eustachian tube of guinea pigs with effusion after being treated by pulmonary surfactant]

OBJECTIVE: To study the effect of pulmonary surfactant on otitis media with effusion in guinea pigs to find a new way to manage otitis media with effusion. METHODS: Nonviable heat-killed pneumococci (HKP) solution was inoculated into the middle ear cavity in guinea pigs via a transeardrum approach to set up a model of otitis media with effusion in guinea pigs. Seven days after being injected with pulmonary surfactant (PS) by transeardrum approach, ABR threshold and histomorphological changes of eustachian tube mucosa of guinea pigs were examined by light microscopy and scanning microscopy. RESULTS: Five days following inoculation of HKB serous effusion were present in the middle ear cavity of guinea pigs, but disappearance of light cone. Response (mean +/- s) threshold raised from (14.0 +/- 3.1) dB to (45.0 +/- 5.7) dB. The eustachian tube mucosa was thickened and lined eosin-stained structureless matter over mucosa, while cilia of eustachian tube mucosa irregularly arranged. Seven days after being treated by PS, serous effusion of tympanum was reduced or disappeared, and response threshold decreased from (45.0 +/- 5.7) dB to (23.5 +/- 6.3) dB. There was significantly difference between them (P < 0.001). Eustachian tube mucosa was thinned, Cilia of eustachian tube mucosa regularly arranged to the nasopharynx. CONCLUSION: Pulmonary surfactant plays a important role in otitis media with effusion of guinea pigs.     

Protective effect of pulmonary surfactant on cilia of Eustachian tube in otitis media with effusion

OBJECTIVE: The aim of this study was to evaluate the effect of pulmonary surfactant (PS) on cilia of Eustachian tube (ET) in guinea pigs suffering from otitis media with effusion (OME). METHODS: A nonviable heat-killed pneumococci (HKP) solution was injected into the tympanum of guinea pig via a transtympanic approach therefore establishing models of OME (effusion in tympanum and hearing loss). After being injected with physiologic saline solution or pulmonary surfactant transtympanically, the response threshold of each guinea pig was taken by ABR. Changes of effusion and ciliary ultrastructure were observed. RESULTS: Normal group (A), the response threshold is 14.00+/-3.08 dBHL. Abundant and intact cilia were observed, ciliary morphology was normal, cilia regularly arranged in concord, no goblet cells was observed. Model-control group (B0), 5 days following the inoculation of HKP, serous effusion was present in tympanum. The response threshold is 45.00+/-5.67 dBHL. Cilia lost and arranged irregularly, hyperplasia of the goblet cells was observed. Saline group, the previously observed serous effusion of tympanum was increased or unchanged. The response threshold is 65.50+/-6.85 dBHL. Cilia were coalescing and swelling. A lot of cilia lost and arranged disorderly. A number of compound cilia of the bulging type were formed by cytoplasmic protuberances of ciliated cells. Massive mucoid secretions stuck on the surface of the ET. PS group, the previously observed serous effusion of tympanum was reduced in amount or disappeared completely. The response threshold is 23.53+/-6.32 dBHL. Ciliary morphology was generally normal. Cilia comparatively arrange in concord. A mucus deposits was adhering to the tips of cilia. CONCLUSION: The findings of the study suggest that pulmonary surfactant plays an important role in protecting of cilia of ET of guinea pigs suffering from OME.     

Ciprofloxacin. Use as a topical otic preparation.

Most common topical otic preparations have been shown to cause sensorineural hearing loss and hair-cell damage in experimental animals. Ciprofloxacin is a relatively new fluoroquinolone with excellent activity against Pseudomonas and methicillin-resistant Staphylococcus aureus. Recent studies have shown oral ciprofloxacin to be effective in the treatment of chronic serous otitis media and malignant external otitis. However, this drug has never been used as a topical otic preparation. Thirty-five albino female guinea pigs were used to investigate the ototoxicity of topical ciprofloxacin hydrochloride. Bilateral transbullae drug delivery tubes were placed and auditory brain-stem response thresholds were recorded at 20, 16, 8, and 4 kHz before treatment and 21 days after the completion of treatment. Two groups of guinea pigs were used. In group 1 (positive controls), five guinea pigs had 0.1 mL of neomycin sulfate administered in one ear while the opposite (control) ear received 0.1 mL of 0.9% sodium chloride solution; in group 2, 30 guinea pigs received 0.75% ciprofloxacin ophthalmic solution and 0.9% sodium chloride solution in the control ear. All drugs were given twice a day for 7 consecutive days. All results were evaluated with paired, two-tailed t test and Hotelling's T2 test, and calculation of power was performed on all nonsignificant results. No significant ototoxic reaction was observed; small increases in hearing thresholds occurred at 4 (5.65 +/- 8.25 dB [mean +/- SD]) and 8 kHz (3.70 +/- 6.63 dB [mean +/- SD]) in the ciprofloxacin-treated ears; however, no significant hair-cell loss was seen.(ABSTRACT TRUNCATED AT 250 WORDS)     

Quantitative experimental assessment of the factors contributing to hearing loss in serous otitis media.

OBJECTIVE: This study was designed to quantitatively assess the contribution of various factors to the conductive hearing loss in otitis media. BACKGROUND: In the conductive hearing loss seen in cases of serous otitis media, various volumes of fluid of different viscosities along with subatmospheric (negative) pressure are found in the middle ear. METHODS: To evaluate the contribution of each of these factors to hearing loss, various volumes of saline, whole blood, or glycerol were applied to the open middle ear cavity of guinea pigs for short periods of time and auditory function was evaluated by recording the threshold of auditory nerve-brainstem evoked responses. In some of the saline experiments, the bulla cavity was also sealed, allowing a subatmospheric (negative) pressure to develop in the cavity as water was osmotically absorbed because of the gradient in colloid osmotic pressure between saline and blood in the vessels lining the middle ear cavity. In other experiments, a thoracic drainage system was connected to the middle ear cavity to induce desired negative middle ear pressures. RESULTS: The degree of hearing loss increased as larger volumes of fluid were introduced into the middle ear, reaching a maximum of 15 to 16 dB. There was no difference in the degree of hearing loss induced by saline or by fluids with viscosities up to 1,000 times greater than that of water (glycerol). A subatmospheric pressure in the middle ear contributed only a small additional (1-2 dB) threshold elevation. CONCLUSION: The major factor contributing to hearing loss in serous otitis media is the volume of fluid in the middle ear, irrespective of its viscosity. The contribution of negative middle ear pressure is much smaller.     

Math1基因内耳导入后噪声性聋豚鼠听功能改变观察

目的观察Math1基因内耳导入对噪声性聋豚鼠听功能的影响,探讨Math1基因过表达对噪声损伤耳蜗的生物学效应,为内耳基因治疗提供实验基础和理论依据。方法经脉冲噪声致聋的豚鼠45只（各频率ABR阈值均≥95dB SPL）,雌雄不限,实验开始时体草250～300g。随机分为3组：Ad—Math1-EGFP组（30只）;Ad—EGFP组（5只）;空白组（10只）。各组豚鼠在基因转导后4周、8周分别测试双耳ABR。测试完毕后处死动物,观察听泡及耳蜗尤炎性病变者记录听阈结果。结果Math1导入后4周,导入耳各频率ABR阈值低于对照耳（右耳）,也低于Ad—EGFP组及空内组,平均达到85dBSPL。Math1导入后8周,导入耳各频率ABR阂值低于对照耳（右耳）,也低于Ad—EGFP组及空白组,与4周时比较,进一步好转,平均达到75dB SPL。结论Math1基因内耳导入可使噪声导致全聋的豚鼠听功能部分恢复,为噪声性聋的治疗打开了新的思路和手段。     

分泌性中耳炎豚鼠的咽鼓管表面活性物质变化

OBJECTIVE: To observe the change of surface active agents of eustachian tube of guinea pigs suffering from secretory otitis media, to explore the effects of surface active agents on secretory otitis media. METHODS: To establish the animal model of guinea pigs suffering from secretory otitis media. To analyse the changes of biochemical component and activity of eustachian tube's surfactant, meanwhile; to observe surfactant change after ectogenic surfactant treatment. RESULTS: The main components of the surfactant decrease in the model group of guinea pigs suffering from secretory otitismedia, phosphatidylcholine (PC) is (19.9 +/- 1.7)%, phosphatidylethanolamine(PE) is (36.8 +/- 2.7)%, minimum surface tension (gamma min) is (18.5 +/- 2.4) mN/m, and PC is (25.7 +/- 2.1)%, PE is (43.7 +/- 3.8)%, (P < 0.001), and gamma min is (7.6 +/- 0.8) mN/m in normal group (P < 0.001). After giving Ectogenic surfactant treatment, PC and PE increase, PC is (23.3 +/- 2.2)%, PE is (42.5 +/- 3.6)%; gamma min reduce, it is (11.8 +/- 2.3) mN/m. CONCLUSIONS: The main biochemical components of the surfactant obviously decrease, the activity of the surfactant weakens in secretory otitis media of guinea pig. This study showed the treatment of Ectogenic surfactant is effective.     

Effect of Nebulized Bovine Surfactant for Experimental Otitis Media with Effusion

Objectives

In this study, we evaluated the efficacy of nebulized bovine pulmonary surfactant on experimentally induced otitis media with effusion (OME) in guinea pigs.

Methods

Twenty guinea pigs were divided into three groups. Four untreated animals served as normal controls. Experimental OME was established in both ears of the remaining 16 animals by a transbullar injection of 10 µL of Pseudomonas aeruginosa lipopolysaccharide in saline. Thereafter, the guinea pigs received nebulized phosphate buffered saline (n=8) or nebulized bovine pulmonary surfactant (n=8). Nebulization was given daily for 7 days. On day 8, all the animals'' passive opening pressure (POP) of the Eustachian tube was measured and histopathological observations of the bulla were made by light microscopy.

Results

Nebulized bovine pulmonary surfactant significantly reduced the POP compared to that of saline nebulization. The bovine pulmonary surfactant improved the tubal patency and produced less histopathologcally-evident edematous bullar mucosa.

Conclusion

Nebulization of bovine pulmonary surfactant plays an important role in treating otitis media with effusion in guinea pigs. Our results suggest that the chosen nebulized bovine pulmonary surfactant can be of good clinical benefit for treating OME in the future.     

急性化脓性中耳炎豚鼠耳蜗形态和功能改变

对3只因听泡置管导致急性化脓性中耳炎发作的豚鼠进行了脑干诱发电位（ABR）测试和耳蜗Corti氏器扫描电镜观察。发现3只豚鼠患耳Corti氏器均有程度不等损害，ABR阈分别提高45、60和30dB。提承急性中耳炎可引起内耳形态和功能变化。文中对引起损害的机制进行了讨论。     

Experimental otitis media with effusion induced by intratympanic lipid A instillation

Otitis media with effusion was induced in guinea pigs by intratympanic instillation of lipid A, the lipid moiety of gram-negative bacterial lipopolysaccharide from Salmonella minnesota Re595. Lipid A was chosen as an inducer because of its similar composition among various bacterial species. Animals were killed from the first to 14th day after instillation of various concentrations (0.2, 2, 20, 200 micrograms/ml) of lipid A in 0.5% triethylamine. By 3 days after instillation, all experimental animals developed serous middle ear effusion. The histologic findings included hemorrhage, mucosal edema, capillary engorgement, and migration of infiltrative cells including macrophages, polymorphonuclear neutrophils, and lymphocytes. These findings were most prominent 3 days after instillation, and the recovery of the middle ear epithelium was observed within 14 days. Repeated instillation of lipid A (2 micrograms/ml) at an interval of 14 days reinforced the local response accompanied by serous middle ear effusion. These findings indicate that lipid A can induce the inflammatory changes with middle ear effusion and that lipid A plays an important role in the pathogenesis of otitis media with effusion.     

Hearing loss induced by viscous fluids in the middle ear

Dextran solutions of low viscosity (7.5 centipoise) and high viscosity (2.2 poise) were instilled in turn into the middle ears of guinea pigs, using an open bulla preparation. The degree of conductive hearing loss induced was assessed by measurement of the cochlear microphonic. Both solutions produced a comparable degree of hearing loss which was frequency dependent, ranging from 30 dB at 500 Hz to almost zero at 4000 Hz. The results indicate that the degree of conductive hearing loss produced by a serous effusion in otitis media is due solely to an effect on compliance in the middle ear and is independent of the viscosity of the effusion.