利用微透析技术对利多卡因治疗耳鸣作用机制的实验研究

目的　探讨利多卡因治疗耳鸣的神经递质学方面的机制。方法　利用微透析技术和微柱高效液相电化学检测方法研究利多卡因对耳鸣动物模型下丘和颞皮层 5 羟色胺 (5 hydroxytryptamine,5 HT)神经递质的影响。结果　 2 6只白色Wistar大鼠水杨酸钠造模耳鸣 ,显示下丘和颞皮层部位 5 HT的水平显著升高 ,分别在水杨酸钠腹腔注射 2h和 3h升高到基础值的 2 6 8%±2 7% ( x±s,以下同 )和 2 77%± 2 4 % ,通过局部脑组织灌流 ,利多卡因能显著性地降低下丘和颞皮层升高了的 5 HT的水平 ,分别降低至基础值的 85 %± 8%和 92 %± 2 6 %。结论　听觉中枢下丘和颞皮层这两个重要部位 5 HT水平的改变可能与利多卡因抑制耳鸣的机制有关。     

水杨酸钠作用后大鼠海马内葡萄糖和乳酸水平变化

目的探讨边缘系统海马在耳鸣发病机制中的作用。方法在水杨酸钠诱导建立的耳鸣动物模型基础上,利用微透析技术结合葡萄糖和乳酸双组分同时在线电化学检测方法 ,活体、实时、动态研究水杨酸钠作用后大鼠海马内葡萄糖及乳酸水平的变化。结果水杨酸钠引起大鼠海马葡萄糖和乳酸水平显著性地升高。在2h内葡萄糖和乳酸分别最高升到基线水平的(234±26)%和(188±14)%,在第4小时和第5小时恢复至基线水平。生理盐水对照组未引起任何明显变化。结论大鼠海马内葡萄糖和乳酸水平的显著性升高提示海马内神经元活动明显增高,这可能与水杨酸钠诱导的耳鸣产生有关,这些活体数据为边缘系统参与耳鸣的发生提供直接的实验证据。     

水杨酸钠对大鼠下丘多巴胺水平影响的研究

目的探讨听觉中枢核团下丘内多巴胺水平的变化在耳鸣发病机制中的作用。方法在水杨酸钠诱导建立的耳鸣动物模型基础上,利用微透析技术结合高效液相电化学检测方法,活体、动态研究水杨酸钠作用后大鼠下丘内多巴胺水平的变化。结果水杨酸钠引起大鼠下丘多巴胺水平显著性地降低。大约3小时后下丘内多巴胺水平降至最低,达到基础值的49±9%,然后缓慢的升高,大约5小时后恢复到基线水平。生理盐水对照组未引起任何明显的变化。结论大鼠下丘内多巴胺水平的显著性降低可能与水杨酸钠诱导的耳鸣产生有关,这些活体数据为多巴胺这一调节人们精神活动的重要递质参与耳鸣的发生提供直接的实验证据。     

水杨酸钠致耳鸣的神经生理学机制研究进展

耳鸣、听力下降和对言语认知能力的减低是水杨酸钠对听觉系统毒副作用最明显的三大症状.本文阐述了水杨酸钠在听觉传导通路如蜗神经、下丘核以及在皮层听区的听觉电生理学作用,如对蜗神经、下丘核以及在皮层听区的神经元的发放率、神经元兴奋的潜伏期、调协曲线等的影响.旨在加深水杨酸钠致耳鸣的神经起源机制的理解.     

水杨酸钠对大鼠下丘内谷氨酸和γ-氨基丁酸的影响

目的探讨水杨酸钠诱导产生耳鸣动物模型时神经递质在其中枢发病机制中的作用。方法利用微透析技术,在活体清醒的状态下检测水杨酸钠诱导的耳鸣动物模型,研究水杨酸钠对听觉中枢核团下丘的神经递质谷氨酸和γ-氨基丁酸的影响。结果腹腔注射10%水杨酸钠（350mg/kg）引起下丘谷氨酸水平的显著性升高,最高达到基础值的236%±19%;γ-氨基丁酸水平显著性降低,最低达到基线水平的50%±12%。对照组（注射生理盐水）并未引起任何显著改变。结论微透析技术活体检测数据表明,下丘内谷氨酸水平的升高和γ-氨基丁酸水平的降低可能和耳鸣的产生有关。     

水杨酸钠诱发大鼠听皮层中GABARAP表达的改变

目的 通过检测水杨酸钠诱导耳鸣大鼠听皮层中GABAA受体相关蛋白(GABAA receptor-associated protein,GABARAP)转运蛋白的表达,研究耳鸣大鼠听皮层是否出现GABARAP蛋白表达的改变,探讨GABARAP在耳鸣中的作用机制.方法 126只SD大鼠,随机等分成7组:对照注射、慢性注射7...     

水杨酸钠致耳鸣的神经生理学机制研究进展

耳鸣、听力下降和对言语认知能力的减低是水杨酸钠对听觉系统毒副作用最明显的三大症状。本阐述了水杨酸钠在听觉传导通路如蜗神经、下丘核以及在皮层听区的听觉电生理学作用，如对蜗神经、下丘核以及在皮层听区的神经元的发放率、神经元兴奋的潜伏期、调协曲线等的影响。旨在加深水杨酸钠致耳鸣的神经起源机制的理解。     

长期注射水杨酸钠对大鼠听皮层酪氨酸受体激酶B及c－fos基因表达的影响

目的通过观察长期注射水杨酸钠后大鼠听皮层中酪氨酸受体激酶B(TrkB)及c-fos基因的表达,探讨其在水杨酸钠耳毒性机制中的作用。方法健康成年Wistar大鼠36只,分为正常组(不做任何处理)、慢性组(肌肉注射水杨酸钠175mg/kg,2次/天,时间间隔8小时,连续注射14天)、慢性恢复组(前期处理同慢性组,停药后恢复28天),每组12只。造模结束后各组大鼠均行听性脑干反应(ABR)检测,然后断头处死并迅速取出听皮层,运用实时荧光定量PCR技术及Western-blot技术分别检测三组大鼠听皮层中TrkB及c-fos的表达。结果正常组ABR反应阈为36±2.23dB SPL,慢性组反应阈升高为41.3±3.31dB SPL,与正常组比较,差异有显著统计学意义(P<0.01);慢性恢复组ABR反应阈为38.6±5.51dB SPL,与正常组比较,差异无统计学意义(P>0.05)。慢性组听皮层c-fos mRNA表达为1.24±0.09,蛋白的表达为0.70±0.12,慢性恢复组听皮层c-fos mRNA的表达为1.23±0.04,蛋白的表达为0.68±0.08,两组均高于正常组(分别为1.12±0.05、0.50±0.04),差异有统计学意义(P<0.01)。慢性组听皮层TrkB mRNA表达为1.26±0.10,蛋白的表达为1.85±0.17,慢性恢复组听皮层TrkB mRNA表达为1.23±0.07,蛋白的表达为1.80±0.08,均高于正常组(分别为1.11±0.03,1.53±0.16),差异有统计学意义(P<0.05)。结论长期注射水杨酸钠后大鼠听皮层c-fos基因表达升高,可能与听觉中枢神经活动增强有关;长期注射水杨酸钠可能通过上调大鼠听皮层TrkB的表达,增强听皮层神经营养因子的功能促进听皮层功能重塑。     

耳鸣模型大鼠听皮层生长相关蛋白-43和细胞骨架活性调节蛋白的表达

目的检测神经元功能可塑性基因生长相关蛋白-43（growth associated protein,GAP-43）和细胞骨架活性调节蛋白（activity regulated cytoskeleton associated protein,ARC）在水杨酸诱导耳鸣大鼠听皮层中的表达,探讨其在耳鸣产生中的作用。方法将24只白色Wistar大鼠随机分为3组：水杨酸钠组（8只）、生理盐水组（8只）和空白对照组（8只）。前两组从条件反射建立前开始于每次条件反射训练前2小时分别腹腔注射10%水杨酸钠溶液（350mg/kg）和同体积生理盐水,至实验结束,空白对照组不做任何处理。通过行为学方法证实水杨酸钠组动物感受到耳鸣后,利用荧光定量PCR检测动物听皮层中GAP-43和ARC的表达。结果水杨酸钠组大鼠听皮层中GAP-43和ARC蛋白阳性神经元的表达（分别为2.17&#177;0.72、4.90&#177;2.13）明显高于生理盐水组（分别为1.05&#177;0.20、1.13&#177;0.42）和空白对照组（分别为0.96&#177;0.97、1.07&#177;0.70）（P〈0.01）,而生理盐水组和空白对照比较差异无统计学意义（P〉0.05）。结论耳鸣大鼠听皮层中神经元功能可塑性基因GAP-43和ARC蛋白阳性神经元的表达增加,推测它们可能在耳鸣的发生发展中起重要作用。     

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.     

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.     

Lack of significant estrogen and progesterone receptor expression in nasal telangiectasias in hereditary hemorrhagic telangiectasia: an immunohistochemical analysis

Obstructive sleep apnea syndrome (OSAS) is characterized by snoring and apnea during sleep leading to decreased oxygen saturation and disturbed sleep, excessive daytime sleepiness and neuropsychological disturbances. This study investigates cognitive neuropsychological abilities in a group of 53 OSAS patients before and after treatment with uvulopalatopharyngoplasty. General intellectual ability, verbal learning and memory as well as executive functioning were measured at baseline and 6 months postoperatively. After surgery there were significant improvements in verbal learning and memory (mean change - 39, SD 57.3, p <0.001), recall (mean change - 24.3, SD 39.3, p <0.001) and executive functioning (as assessed by percentage of errors on the Wisconsin Card Sorting Test; mean change-9.1, SD 15.7, p <0.001). These improvements were in accordance with improvements in the degree of sleep apnea, the oxygen desaturation index (mean change -9.7, SD 15.9, p <0.001) and arterial minimum oxygen saturation (mean change 4.5%, SD 10.2%, p <0.01). Surgical treatment seems to improve verbal learning, memory and recall and executive functions in parallel with better oxygenation in OSAS.     

Measurement of chemosensory function

Although hundreds of thousands of patients seek medical help annually for disorders of taste and smell, relatively few medical practitioners quantitatively test their patients' chemosensory function, taking their complaints at face value. This is clearly not the approach paid to patients complaining of visual, hearing, or balance problems. Accurate chemosensory testing is essential to establish the nature, degree, and veracity of a patient's complaint, as well as to aid in counseling and in monitoring the effectiveness of treatment strategies and decisions. In many cases, patients perseverate on chemosensory loss that objective assessment demonstrates has resolved. In other cases, patients are malingering. Olfactory testing is critical for not only establishing the validity and degree of the chemosensory dysfunction, but for helping patients place their dysfunction into perspective relative to the function of their peer group. It is well established, for example, that olfactory dysfunction is the rule, rather than the exception, in members of the older population. Moreover, it is now apparent that such dysfunction can be an early sign of neurodegenerative diseases such as Alzheimer's and Parkinson's. Importantly, older anosmics are three times more likely to die over the course of an ensuring five-year period than their normosmic peers, a situation that may be averted in some cases by appropriate nutritional and safety counseling. This review provides the clinician, as well as the academic and industrial researcher, with an overview of the available means for accurately assessing smell and taste function, including up-to-date information and normative data for advances in this field.