耳廓软骨天然生物支架材料的制备及初步研究

目的探讨制备兔耳廓天然软骨细胞外基质材料的新方法,制备适用于组织工程应用的天然生物支架材料.方法①采用多步骤去污剂-酶处理技术抽提兔耳廓软骨细胞制备天然软骨细胞外基质(Nature Extracellular Matrix,NECM),对NECM行HE染色、澳新蓝染色、维多利亚蓝染色、VanGieson染色并进行组织学及扫描电镜观察;②以灰家兔NECM为支架材料和新西兰大白兔耳廓软骨细胞为种子细胞进行体外培养,倒置显微镜下观察其亲水性和对细胞的吸附力,并通过四氮唑盐比色法(MTT Assay)观察NECM对软骨细胞的增殖作用.结果通过HE染色、蛋白多糖、胶原及弹力纤维特染、扫描电镜观察分析证实经过多步骤去污剂-酶法抽提软骨细胞制备的天然生物支架材料里,不含细胞及细胞器成分,仅含有不溶解的胶原、弹性蛋白和蛋白多糖,亦即NECM;体外培养实验发现,兔耳廓软骨细胞易进入脱细胞异体软骨基质结构裸露的空穴,且生长旺盛,组织学检查证实兔耳廓软骨NECM上裸露的骨陷窝已部分被软骨细胞占据.MTT Assay检测证实NECM对软骨细胞增殖有促进作用.结论本实验制备的NECM脱细胞彻底、细胞外基质成分保留较完整,并具有促进细胞粘附、增殖和分化生长的作用,是一种较为理想的天然生物支架材料.     

同种异体软骨细胞修复耳廓缺损的动物实验研究

目的探讨兔同种异体软骨细胞和自行制备生物材料高孔隙率聚乳酸(poly—DL-lactide,PDLLA)支架复合物修复兔耳廓软骨缺损的可行性。方法 18只大白兔分为软骨细胞/PDLLA复合物移植组、单纯PDLLA对照组和空白对照组,将体外培养的兔同种异体软骨细胞和自行制备的PDLLA支架形成复合物,修复兔耳廓软骨缺损。分别于植入后6周、12周、18周取材,HE和甲苯胺蓝染色了解兔耳廓缺损修复情况。结果术后18周,软骨细胞/PDLLA复合物移植组软骨缺损区为软骨组织修复,新生软骨与正常软骨问连接好,单纯PDLLA对照组和空白对照组为纤维软骨或纤维组织修复。结论同种异体软骨细胞/自制PDLLA复合物移植可较好地修复兔耳廓软骨缺损。     

自体骨髓间质干细胞诱导的软骨细胞修复兔耳廓软骨缺损

目的探讨自体骨髓间质干细胞（Bone marrow mesenchymal stemcells,BMMSC）诱导的软骨细胞修复兔耳廓软骨缺损的可行性。方法取新西兰大白兔BMMSC体外培养扩增,以含转化生长因子（TGF-β1）、地塞米松和维生素C的培养液做诱导培养,实验组以诱导后的软骨细胞与聚丙交酯-乙交酯共聚物Poly（dl-lactideco-glycolide）（PLGA）包埋甲壳胺无纺布的新型支架形成复合物修复兔自体耳廓软骨缺损;对照组以PLGA/甲壳胺无纺布支架修复兔耳廓软骨缺损。分别于移植后6周、12周、18周取材,行HE和甲苯胺蓝染色,观察各组兔耳廓软骨缺损修复情况。结果术后18周,实验组缺损区完全由软骨组织修复,缺损表面光滑,软骨陷窝明显,与周围正常软骨组织无明显界限;对照组为纤维组织修复。结论自体BMMSC诱导的软骨细胞可用于修复兔耳廓软骨缺损。     

转化生长因子β1和同种异体软骨细胞及高孔隙率聚乳酸复合物修复兔耳廓软骨缺损

目的　观察加入转化生长因子 β1(transforminggrowthfactor beta 1,TGF β1)的同种异体软骨细胞 /高孔隙率聚乳酸 (poly DL lactide,PDLLA)支架复合物修复兔耳廓软骨缺损的效果。 方法18只大白兔随机分为同种异体软骨细胞 /PDLLA复合物加TGF β1组 (复合物组 )、同种异体软骨细胞 /PDLLA复合物组 (复合物对照组 )和不用任何修复材料的空白对照组 ,每组 6只。分别于 4、12、18周取材 ,行HE和甲苯胺蓝染色 ,观察各组兔耳廓软骨缺损修复情况。结果　术后 18周 ,TGF β1复合物组修复软骨缺损的效果无论从大体标本观察或是病理组织学检查都比复合物对照组的修复效果好 ,空白对照组为纤维组织修复。结论　同种异体软骨细胞 /PDLLA复合物移植可形成组织工程化软骨修复兔耳廓软骨缺损 ,TGF β1可提高同种异体软骨细胞 /PDLLA复合物移植修复兔耳廓软骨缺损的质量。     

转化生长因子β1和同种异体软骨细胞及高孔隙率聚乳酸复合物修复兔耳廓软骨缺损

目的 观察加入转化生长因子-β1(transforming growth factor-beta1，TGF-β1)的同种异体软骨细胞／高孔隙率聚乳酸(poly-DL-lactide，PDLLA)支架复合物修复兔耳廓软骨缺损的效果。方法 18只大白兔随机分为同种异体软骨细胞／PDLLA复合物加TGF-β1组(复合物组)、同种异体软骨细胞／PDLLA复合物组(复合物对照组)和不用任何修复材料的空白对照组，每组6只。分别于4、12、18周取材，行HE和甲苯胺蓝染色，观察各组兔耳廓软骨缺损修复情况。结果 术后18周，TGF-β1复合物组修复软骨缺损的效果无论从大体标本观察或是病理组织学检查都比复合物对照组的修复效果好，空白对照组为纤维组织修复。结论 同种异体软骨细胞／PDLLA复合物移植可形成组织工程化软骨修复兔耳廓软骨缺损，TGF-β1可提高同种异体软骨细胞／PDLLA复合物移植修复兔耳廓软骨缺损的质量。     

中华耳科学杂志2004年第2卷作者索引

B毕胜斌自制NECM修复兔耳廓软骨缺损的试验研 (1):48C陈雄血管内皮生长因子在中耳胆脂瘤中的表达及其临床意 (2):129陈乾美ki-67、细胞周期蛋白依赖性激酶4在胆脂瘤型中耳乳突炎中的表达及意 (2):126陈洪文测听室的隔声与屏 (3):227陈雷离体豚鼠前庭神经节细胞的分离及胞内钙离子活动的观 (3):215陈文文自体臼枪柱状听骨的听力疗效观 …     

由软骨膜再生软骨的实验研究和临床应用

早在1971年Skoog等用兔耳进行软骨膜再生软骨的研究:一耳切除部分软骨及软骨膜,如此形成的映损4周后依然存在;另一耳只切除软骨,但用软骨膜瓣覆盖缺损处,2周后可见缺损处为不成熟的软骨桥所填满。1975年氏等又将切除范围扩大到2×2cm,仍可见到覆盖的软骨膜引起软骨膜桥再生。为除外由缺损的软骨边缘发生再生的可能,又在软骨缺损区内先放一聚四氟乙烯环,再将软骨膜辦覆于软骨上,结果在环内由覆盖的软骨膜形成了新的软骨盘,如盘内充满血液,则新生的软骨增多。上述的软骨膜瓣营养来自基底部,所以游离软骨膜瓣可能同样起作用。因此本文作者用游离软骨膜瓣移植于有血液供应的部位(颈部皮下组织、背部肌肉、肝实质),同样有新软骨形成。这是因为软骨膜含有间叶细胞,并具有固有的再生能力。通过实验还证明了     

软骨膜和脱钙骨基质联合移植修复鼻翼软骨缺损

目的探讨软骨膜与同种异体脱钙骨基质（demineralized bone matrix,DBM）联合移植对鼻软骨缺损的修复效果。方法新西兰兔18只随机分为3组,每组6只。制作鼻翼软骨和软骨膜缺损模型,于缺损处移植修复组织。A组为自体耳软骨膜包裹同种异体DBM;B组为自体耳软骨;C组为自体耳软骨膜。10周后取缺损处软骨行大体和病理组织学观察,S100（Soluble protein-100）、转化生长因子β1（transforming growth factor-β1,TGF-β1）免疫组化染色,评价修复效果。结果 A、B两组所得软骨细胞和基质与正常软骨相类似,两组比较差异不明显。C组所得软骨细胞少,基质浅淡,S100、TGF-β1染色阳性细胞少,与A、B组比较均有统计学意义（P〈0.01）。结论软骨膜与同种异体DBM联合移植对鼻软骨缺损的修复效果与自体软骨基本一致,明显优于自体软骨膜移植。     

聚羟基乙酸负载软骨细胞修复同种异体甲状软骨缺损

目的 探讨聚羟基乙酸(polyglycolic acid，PGA)负载软骨细胞在有免疫力动物修复同种异体甲状软骨缺损的可行性。方法 酶消化法获取3天龄新西兰乳兔肋软骨和关节软骨细胞，采用组织工程技术制备软骨细胞-PGA复合物，体外共同培养1周后用于修复同种异体成年新西兰白兔甲状软骨缺损(实验组7只)。设单纯PGA材料修复组(对照A组4只)和单纯软骨细胞修复组(对照B组4只)作为对照实验。分别于术后不同时间取材，对甲状软骨缺损的修复效果进行大体和组织学评价。结果 体外培养阶段可见黏附于PGA纤维表面的细胞分泌出丰富的软骨基质，呈蜘蛛网状分布于PGA纤维之间。术后4周大体观察：实验组修复区呈淡黄色，与正常软骨界限分明；组织学检查：修复区内有软骨细胞生成和基质分泌，但与正常软骨间存在界面无细胞区，未见明显炎细胞浸润。8周：实验组修复区色乳白，与正常软骨仍有界限；镜下见修复区软骨细胞较成熟，软骨基质含量丰富。12周：实验组修复区呈瓷白色，界面区软骨细胞不明显，但修复区软骨细胞数量、形态和基质与正常软骨相似。各时间点对照组大体观察修复区均呈不同程度的凹陷，暗红色，部分软组织充填其中，质软；组织学及特殊染色检查未发现软骨样结构及其分泌的基质成分。新生软骨内未见血管生长。结论PGA负载软骨细胞能修复具有正常免疫功能同种异体兔甲状软骨缺损，但新生软骨与正常软骨间存在无细胞区界面，无明显免疫排斥。     

气管食管科学

20021433游离兔耳软骨移植修复广泛气管前壁缺损的研究/张瑞林…//华西医科大学学报一2002,33(2)一270一273 目的:探讨用游离兔耳廓软骨修复广泛气管前壁缺损的可行性,并观察自体移植与异体移植的差异。方法:取新西兰大耳白兔2。只,分为自体移植组(n一10)与异体移植组(n一10),取右耳游离耳廓软骨行自体或异体移植修复8~10环气管前壁缺损,术后l、2、4、8于口12周每组分别处死1~2只行内窥镜检查、生物力学测试及组织学观察。结果:18只兔存活,内窥镜发现气管狭窄不明显,以癖痕增生为主。生物力学测试发现,移植软骨单位最大应力在。、4、8、12周…     

One‐stop neck lump clinic: phase 2 of audit. How are we doing?

One‐stop neck lump clinic: phase 2 of audit. How are we doing? Regular monitoring and audit of a service are integral to ensuring maintenance of efficiency and standards. This is particularly important where the quality of the service is operator dependent, as is the case in the clinical diagnosis of neck lumps and fine needle aspiration cytology. The one‐stop neck lump clinic has now been running in the department for more than 20 months. A previous article described the results of the first phase audit carried out at 6 months and had identified a waiting time to be seen that was longer than that recommended by the British Association of Otorhinolaryngologists, Head and Neck Surgeons. Measures were implemented to reduce this waiting time and a second audit was carried out after another 10 months with the aims of assessing if modification of the means of referral reduces waiting time and if the outcomes of clinical performance in phase 1 could be maintained or improved. We discuss the results of phase 2 in the audit spiral.     

A Decrease in Maxillary Sinus Pressure,as Seen in Upper Airway Allergy or Infection,Results in an Increase in Upper Airway Nitric Oxide Levels

The paranasal sinuses are connected to the nasal cavity via small osties. Ostial occlusion, caused by mucosal swelling, will result in a slowly increasing negative pressure inside the sinus cavity. In parallel, the oxygen content in the sinus will decrease, resulting in the development of relative hypoxia. Hypoxia is a powerful inducer of nitric oxide (NO) synthase, and inducible NO synthase has been shown to be present in considerable amounts in the upper airways, including the sinuses. The present study was designed to investigate whether a reduction in sinus pressure would affect upper airway NO production. Thirteen healthy volunteers were investigated. A pressure chamber was used to lower the ambient pressure to-4.9 kPa. NO was sampled from one nostril or via a drainage tube inserted into the maxillary sinus before, during and after the hypobaric exposure. When the pressure was decreased, NO levels increased from 256 &#45 15 to 316 &#45 19 ppb ( n =13, p <0.001). The NO levels remained elevated (282 &#45 21 ppb; p <0.05) when measurements were repeated 20 min after leaving the chamber. The nasal airway resistance (V2 tot ) also increased as a result of the chamber session (from 16 &#45 2° before to 21 &#45 3° after; p <0.05). An increase in NO levels was also found when the experiments were repeated with NO sampled directly from the maxillary sinus (225 &#45 6 before and 265 &#45 9 ppb after; n =6, p <0.001). For control purposes the nasal analyses were repeated again, this time under hyperbaric conditions (+4.9 kPa). This resulted in a slight decrease in the NO levels (from 273 &#45 22 to 241 &#45 17 ppb; n =10, p <0.001), but there was no change in the nasal airway resistance. We conclude that a reduction in sinus pressure, as seen in upper airway allergy or infection, may result in an increase in upper airway NO production.     

Physiologische Grundlagen einer Hörprothese

Zusammenfassung Im Bemühen, eine Hörprothese zu entwickeln, die ein Sprachverständnis erlaubt, erscheint es zumindest fürs erste am zweckmäßigsten, durch künstliche elektrische Reizung des Hörnerven die natürlichen Verhältnissen so gut als möglich zu imitieren. Der normale Hörnerv enthält etwa 30000 Nervenfasern, die sich qualitativ gleich, quantitativ jedoch unterschiedlich verhalten, wobei über die Eigenschaften der von den ÄHZ kommenden Spiralfasern im Augenblick sichere Aussagen nicht möglich sind (siehe 2.3). Die quantitativen Unterschiede zwischen den einzelnen Hörnervenfasern beziehen sich auf deren Frequenzabstimmung, Frequenzselektivität, Schwellen, Intensitätsfunktionen und — wichtig insbesondere für das Vorhaben einer künstlichen elektrischen Reizung — in Zeitunterschieden in den Aktivitätsmustern, die durch Laufzeitunterschiede auf der Basilarmembran bedingt sind (2.3). Diese Zeitunterschiede in der Aktivität einzelner Fasern liegen im Bereich mehrerer ms (2.3.6; 2.3.7). Die durch Schallreize im normalen Hörnerven ausgelösten Aktionspotentiale haben überdies einen probabilistischen Charakter, d. h. ihr Auftreten ist keineswegs streng determiniert. Es versteht sich von selbst, daß man bei künstlicher, elektrischer Reizung nicht alle verbliebenen Nervenfasern selektiv reizen kann. Somit wird eine Reizelektrode immer eine Gruppe von Nervenfasern erregen müssen. Bei jeder denkbaren elektrischen Reizung wären alle Fasern im Reizbereich einer Elektrode synchron und streng deterministisch aktiviert, was einen außerordentlich ernstzunehmenden Unterschied zu natürlichen Verhältnissen darstellt (3.2).Um die Zahl der zum Sprachverständnis mindestens notwendigen Reizkanäle abzuschätzen, wird man, in Ermangelung anderer experimenteller Daten, von psychoakustischen Untersuchungen an Normalhörenden auszugehen haben. Diese haben gezeigt, daß das Gehör neben einer außerordentlichen Fähigkeit verschiedene Tonhöhen zu unterscheiden, andererseits die Fähigkeit besitzt, bestimmte Frequenzgebiete zu sogenannten Frequenzgruppen zu integrieren. Die in eine solche Frequenzgruppe fallende Schallenergie wird zu einem einheitlichen Höreindruck verarbeitet. Es scheint also sinnvoll, die für einen Prothesenbau notwendige Zusammenfassung von Gruppen von Fasern des Hörnerven in verschiedene Reizkanäle entsprechend diesen Frequenzgruppen vorzunehmen (3.1). Demnach müßte der Sprachbereich in 15 Reizkanäle aufgeteilt werden, was wiederum, wenn man in der Cochlea reizen will, 1,2 mm Abstand von Kanal zu Kanal erlauben würde. Dabei müßte der Reizerfolg sauber auf die einzelnen Kanäle beschränkt bleiben, d.h. eine optimale Kanaltrennung erreicht werden. In Anbetracht der groben Abweichungen der neuronalen Aktivität vom normalen Verhalten, die bei künstlicher, elektrischer Reizung unvermeidlich sind, ist freilich unsicher, ob die angegebene Zahl ausreichen würde. Andererseits ist es in Anbetracht der zu erwartenden Stromverteilung im Sprachbereich kaum vorstellbar, mehr als die angegebene Zahl von Kanälen realisieren zu können.Was die Kodierung der Schallparameter innerhalb eines Elektrodenkanals betrifft, wird vorgeschlagen, die Frequenzkodierung nach dem Ortsprinzip optimal auszunutzen, und im Hinblick auf die Periodizitätsanalyse und die Lautheitskodierung sich soweit als möglich den natürlichen Verhältnissen anzunähern (3.3). Dabei wären Laufzeitunterschiede zwischen den Kanälen und der probabilistische Charakter der neuronalen Entladungen soweit als möglich einzuführen, um die Dominanz eines periodicity pitch zu vermeiden.Eine für Sprachverständnis ausreichende Prothese ist auch nur denkbar, wenn eine Prothese die zur Sprachübertragung notwendige Übertragungskapazität besitzt. Ergebnisse der Kanal-Vocoder-Technik zeigen, daß Sprache noch mit 1500 bit/s befriedigend übertragen werden kann. Eine Abschätzung der möglichen Leistungsfähigkeit einer 15-kanaligen Prothese (3.4), basierend auf der Zahl der möglichen unterscheidbaren Unterschiedsstufen der Hörempfindung, ergibt, daß diese Übertragungskapazität knapp erreicht werden könnte. Allerdings ist damit noch nicht gesagt, daß das Zentralnervensystem die angebotene Information auch im Sinne einer Phonemanalyse auswertet und damit für ein Sprachverständnis maximal ausschöpft. Nur für diesen Fall wäre ein Sprachverständnis zu erwarten.Als Reizort erscheint in erster Linie die Cochlea (5.1) geeignet. Für den Fall einer Degeneration der primären afferenten Fasern des Hörnerven ist aufgrund physiologischer Überlegungen auch der Nucleus cochlearis ventralis (5.5) interessant, allerdings würde so nur der ventrale Anteil der Hörbahn stimuliert. Doch besitzen auch andere Reizorte spezifische Vorteile (5.2–5.4).Theoretische Überlegungen (6.1) und experimentelle Messungen an implantierten Elektrodensätzen (6.3) zeigen, daß die Forderung der Kanaltrennung nur schwer zu erreichen sein wird. Deswegen wird der dynamische Bereich (im Hinblick auf Veränderung des Reizstromes) eines nach den obigen Kriterien konstruierten Reizkanals auf maximal 3 dB zu beschränken sein, so daß Erregungsausbreitung auf weitere Bereiche der Cochlea durch Ansteuerung von mehreren Reizkanälen zu imitieren wäre.Die Chancen, eine Prothese zu verwirklichen, die befriedigendes Sprachverständnis auf der Basis einer quasinatürlichen Reizung des Hörnerven erlaubt, wird von uns in Anbetracht der geschilderten mannigfaltigen Schwierigkeiten als sehr niedrig angesehen. In Anbetracht des großen Nutzens, der andererseits eventuell resultieren könnte, halten wir die Erforschung des Problems jedoch für angebracht.Es wird von uns vorgeschlagen, auch zu untersuchen, ob sich für eine prothetische Versorgung vorverarbeitete Sprache besser eignet (7.). Für Prothesen, die ein Sprachverständnis nicht anstreben, halten wir eine Implantation in die Cochlea für überflüssig. Hier erscheint uns die Implantation von Reizelektroden am runden Fenster (Douek et al., 1977; Fourcin et al., 1978; s. a. 1. und 7.) wegen des geringeren Risikos der überlegenere Weg.Die zitierten eigenen Arbeiten der Autoren wurden mit Unterstützung der DFG durchgeführt (DFG-K1 219).     

The expression of vascular endothelial growth factor (VEGF) and VEGF‐C in early laryngeal cancer: relationship with radioresistance

The expression of vascular endothelial growth factor (VEGF) and VEGF‐C in early laryngeal cancer: relationship with radioresistance Angiogenesis is essential for tumour growth and invasion. Vascular endothelial growth factor (VEGF) is a prime mediator of tumour angiogenesis. VEGF‐C is a closely related protein that effects lymphatic endothelial cells and may be important in the process of lymphatic metastasis. The purpose of this study was to evaluate the expression of these cytokines in patients with T1 and T2a glottic, squamous cell carcinoma, in comparison with normal epithelial control tissue, to ascertain any association with radioresistance. Twenty‐two tumours treated by radiotherapy (13 radiosensitive, nine radioresistant) and seven normal control tissues were studied. The minimum follow‐up was 2 years after radiotherapy. Expression of VEGF and VEGF‐C was evaluated by immunohistochemistry of formalin‐fixed, paraffin‐embedded biopsy specimens. Analysis was carried out using a quantitative computer image analyser. Both VEGF and VEGF‐C were detectable in tumour and normal control specimens. There was increased expression in tumour specimens of both VEGF (P = 0.03) and VEGF‐C (P < 0.001). In addition, the expression of VEGF‐C was associated with tumours of higher histological grade (P = 0.021). There was, however, no difference in VEGF and VEGF‐C expression between radioresistant and radiosensitive tumours. The expression of VEGF and VEGF‐C is increased in early laryngeal squamous cell carcinoma (SCC). However, measuring the expression of these proteins cannot predict radioresistance in this tumour group.     

Limited Surgery for Cancer of the Larynx and Hypopharynx: Options and Consequences

We reviewed surgical options for laryngeal preservation (limited surgery) in laryngeal and hypopharyngeal cancers and the consequences of the options. Of 44 patients with laryngeal cancer, 11 (25%) received limited surgery and 33 (75%) received total laryngectomy. The survival rates were 91% for the limited surgery group and 73% for the total (radical) surgery group. Of 31 patients with hypopharyngeal cancer, 7 (23%) received limited surgery and 24 (77%) received total laryngopharyngectomy. The survival rates were 53% for the limited surgery group and 40% for the total (radical) surgery group. The survival rates associated with limited surgery were thus better than those for total (radical) surgery for cancers of both the larynx and hypopharynx. This was attributed to the limited surgery group comprising well-selected patients with confined lesions. Organ preservation surgery should be technically simple, reliable in terms of its functional impact and, above all, should not jeopardize the patient's survival. Supracricoid subtotal laryngectomy with cricohyoidoepiglottopexy or cricohyoido-pexy has great potential for laryngeal preservation and will become the major limited surgery modality for treating cancer of the larynx. Limited surgery, however, needs to be performed with great care and is indicated only for very well-selected patients with cancer of the hypopharynx.     

Treatment of Maxillary Sinus Carcinoma: Clinical Results Using the Kitasato Modality

The conventional therapeutic regimen for maxillary sinus carcinoma consists of dissection of the maxilla, full-dose irradiation and extensive chemotherapy. However, the results obtained with this treatment are often poor. Even when patients recover, their quality of life is significantly reduced as a result of deformity of facial structures and swallowing and articulation dysfunctions. A retrospective analysis of 68 patients with maxillary sinus carcinoma treated with the Kitasato modality between 1975 and 1999 was conducted. All patients underwent pergingival maxillary sinus surgery combined with pre- and postoperative irradiation therapy with standardized total doses of 16 Gy; the postoperative irradiation was given in combination with regional intra-arterial infusion chemotherapy administered via the superficial temporal artery. All visible tumor lesions were removed where possible in order to preserve or facilitate cellular immunity after surgery. The cumulative 5-year survival rates were 85.7% for Stage II patients, 88.1% for Stage III, 76.6% for Stage IVA and 75.0% for Stage IVB.     

Cervical Reflex Induced by Click Stimuli in Cats

We studied click-evoked potentials in the anterior horn of the spinal cord in 17 cats. A concentric needle electrode was inserted into the anterior horn of the spinal cord at levels C3-C6. Potentials evoked with 105 dB SPL clicks were recorded with a peak latency of 4.89-5.10 ms only at the C3 level. These responses were observed 45-60 dB SPL above the auditory brainstem response (ABR) threshold, and no potentials were evoked by stimulation of the contralateral ear. Average was performed 100 times with changes in stimulation frequency of 1-20 Hz. The amplitude of the potentials decreased with increasing stimulus frequency, but there were no changes in ABRs. The responses disappeared after destruction of the medial vestibulospinal tract at the obex level, but ABRs were still recorded. The spinal nucleus of the accessory nerves was located in the anterior horn of the spinal cord at levels C1-C6, and the sternocleidomastoid muscle motoneurons were found at levels C1-C3. The click-evoked potentials recorded in this study reflect responses of the spinal nucleus of accessory nerves through the vestibulospinal tract to click stimulation. The responses have the same characteristics as vestibular-evoked myogenic potentials that can be recorded using surface electrodes over the sternocleidomastoid muscles of humans.     

Tongue Base Reduction with Temperature-controlled Radiofrequency Volumetric Tissue Reduction for Treatment of Obstructive Sleep Apnea Syndrome

In recent years a considerable effort has been made to establish the use of different surgical techniques for the treatment of obstructive sleep apnea syndrome (OSAS). Nevertheless, treatment of hypopharyngeal obstruction due to tongue base hypertrophy remains in many ways an unsolved problem. The aim of this study was to evaluate the safety and efficacy of tongue base reduction with temperature-controlled radiofrequency volumetric tissue reduction in the treatment of OSAS. Twenty patients with OSAS and tongue base hypertrophy were treated with radiofrequency tissue ablation. An intensified treatment protocol was used, delivering 2,800 J per treatment session under local anesthesia. Two nights of polysomnography testing were performed before and after treatment. Daytime sleepiness, snoring and postoperative morbidity were assessed using questionnaires. Mean respiratory disturbance index (RDI) was reduced from 32.1 to 24.9/h after a mean of 3.4 treatment sessions. Six patients (33%) were cured after the procedure (reduction in RDI of &#83 50% and a postoperative RDI of <15/h) and ten (55%) showed an improvement of >20% in their RDI. Daytime sleepiness and snoring improved significantly. Peri- and postoperative morbidity was low; one severe complication occurred (tongue base abscess). We were able to achieve similar cure and responder rates to those reported in a recently published pilot study but with a reduced number of treatment sessions. We believe that this technique may improve patient acceptance and have beneficial cost implications.     

Cochlear Function in Ears with Immunomediated Inner Ear Disorder

The aim of the present study was to evaluate the performance of ears with inner ear disorder, responsive to immunosuppressive drugs, in advanced tests designed to assess primary cochlear functions (temporal integration, frequency selectivity, cochlear mechanics). The results of this study suggest that immunomediated inner ear disease results, in the acute clinical stage, in the development of endolymphatic hydrops, which increases the stiffness of the vibrating structures within the inner ear and causes dysfunctions of the outer hair cells. Our patients presented with upsloping or flat sensorineural hearing loss, absence of evoked otoacoustic emissions and distortion-product otoacoustic evoked emissions and abnormal temporal integration, frequency selectivity and cochlear mechanics. Following immunosuppressive treatment, hydrops recovered, hearing subsequently returned to normal, the audiometric curve became flat at low-to-middle frequencies and primary cochlear function tended to normalize. This study seems to support the usefulness of testing primary cochlear functions in order to monitor the clinical course of immunomediated inner ear disorders.     

Bacterial Interference Between Pathogens in Otitis Media and Alpha-Haemolytic Streptococci Analysed in an In Vitro Model

Bacterial interference studied by means of agar methods has shown a decreased number of inhibitory alpha-haemolytic Streptococci among otitis-prone children. Additional information was gained regarding the interplay between alphahaemolytic Streptococci (AHS) and otitis media (OM) pathogens by comparing the bacterial interference in broth with the interference activity studied using agar overlay methods. We found that non-typeable Haemophilus influenzae (NTHI) and Moraxella catarrhalis are readily inhibited by AHS in broth. Streptococcus pneumoniae was more bacteriostatically inhibited. If two OM pathogens were inoculated simultaneously, an isolate of AHS with poor inhibitory activity was not able to inhibit the growth, in contrast to an isolate of AHS with good inhibitory activity. The initial amount of AHS inoculated with M. catarrhalis seemed to play a decisive role with respect to the inhibitory activity. M. catarrhalis developed reduced susceptibility against AHS both in vivo and in vitro . In vivo studies showed that children with secretory otitis media had fewer isolates of AHS in their nasopharynx with the ability to inhibit all the test pathogens than healthy children ( p < 0.001). Although the factor(s) responsible for the inhibitory activity have thus far not been defined, we could exclude low pH and nutrition depletion as the inhibitory mechanism of AHS with good inhibitory activity.