卡那零素再次耳中毒后听功能变化的实验研究

背量：鸡卡那霉素初次耳中毒后其内耳的功能及形态变化已有较多研究，有关再次耳中毒后听功能的变化目前报道尚少。目的：探讨鸡卡那霉素再次耳中毒后听功能的损伤及恢复。设计：完全随机设计。地点和材料：本实验完成于上海第二医科大学新华医院。所用动物为新生罗曼鸡。干预：将雏鸡于初次耳中毒后16d开始再次每天肌注卡那霉素(200mg／kg)，共10d。主要观察指标：于再次药毕后1，7，10，15d进行听脑干反应(auditory brain-stem response，ABR)检测，观察其阈值、阈值时I波潜伏期和振幅变化。结果：首次耳中毒时，小鸡听功能损失于药毕时达到极限。停药后即迅速开始恢复，药毕7d时，鸡ABR阈值有明显下降，药毕10d时，ABR阈值恢复稳定。再次施药10d完毕时，小鸡ABR阈值再次明显升高，但其程度较初次损伤时为轻(107．14vs 116．32)，药毕后鸡听功能恢复更快，再次药毕7d时鸡ABR阈值已恢复稳定，与再次药毕1d时相比，差异有非常显著性意义(P<0．01)，此后鸡ABR阈值未见明显变化。结论：鸡卡那霉素再次耳中毒时，其听功能损失程度较初次损伤时为轻，恢复速度亦较初次损伤时为快。结果提示鸡卡那霉素初次耳中毒后，其基底乳头对卡那霉素的再次损伤具有一定程度的抵抗力。     

糖皮质激素耳后注射治疗突发性聋的效果

目的 比较耳后注射和全身应用糖皮质激素治疗突发性聋的效果.方法 收集2018年1月至2020年12月阜阳市第六人民医院177例突发性聋患者病历资料,其中50例低频下降型突发性聋和43例中高频下降型突发性聋用甲泼尼龙琥珀酸钠行耳后注射、46例低频下降型突发性聋和38例中高频下降型突发性聋行静脉滴注地塞米松磷酸钠,比较两种...     

听力阈值变化与卡那霉素耳慢性中毒豚鼠耳蜗细胞凋亡

目的：探讨卡那霉素耳慢性中毒后豚鼠耳蜗细胞凋亡现象及其在听力损伤中的作用。方法：实验于2003-01／12在第三军医大学大坪医院野战外科研究所完成。75只豚鼠随机分为正常对照组(n=15)，卡那霉素耳慢性中毒组(n=60)。卡那霉素耳慢性中毒组进行硫酸卡那霉素200mg／(kg&;#183;d)连续肌肉注射14d，根据停药时间分为卡那霉素停药1，3，7，14d组，每组15只。分别处死正常对照组及卡那霉素停药1，3，7．14d组豚鼠，处死前检测其听脑干反应的变化，处死后以原位末端标记技术及耳蜗毛细胞核荧光染色计数等检测耳蜗细胞凋亡情况。结果：①豚鼠连续应用卡那霉素14d，停药1d耳蜗细胞即出现凋亡现象(原位缺口末端标记法阳性细胞数：柯蒂氏器0．69&;#177;0．57，螺旋神经节1．22&;#177;0．51．血管纹1．01&;#177;0．67)，随停药时间延长，耳蜗细胞凋亡数增多(14d组原位缺口末端标记法阳性细胞数：柯蒂氏器4．91&;#177;0．94，螺旋神经节8．84&;#177;1．35，血管纹7．39&;#177;1．63)，且愈近底回愈多，愈近顶回则愈少．对照组无凋亡现象。②豚鼠卡那霉素耳慢性中毒后，随停药时间延长，听脑干反应阈值14d组为43，20&;#177;6．73，正常对照组为5，60&;#177;1．78，14d组较正常对照组明显上升(P&;lt;0．01)。结论：①卡那霉素耳慢性中毒可引起耳蜗细胞发生凋亡，细胞凋亡是豚鼠耳蜗损伤的一条途径。②耳蜗细胞凋亡可能是卡那霉素耳慢性中毒听力损伤的形态学基础之一。     

听力阈值变化与卡那霉素耳慢性中毒豚鼠耳蜗细胞凋亡

目的:探讨卡那霉素耳慢性中毒后豚鼠耳蜗细胞凋亡现象及其在听力损伤中的作用。方法:实验于2003-01/12在第三军医大学大坪医院野战外科研究所完成。75只豚鼠随机分为正常对照组(n=15),卡那霉素耳慢性中毒组(n=60)。卡那霉素耳慢性中毒组进行硫酸卡那霉素200mg/(kg·d)连续肌肉注射14d,根据停药时间分为卡那霉素停药1,3,7,14d组,每组15只。分别处死正常对照组及卡那霉素停药1,3,7,14d组豚鼠,处死前检测其听脑干反应的变化,处死后以原位末端标记技术及耳蜗毛细胞核荧光染色计数等检测耳蜗细胞凋亡情况。结果:①豚鼠连续应用卡那霉素14d,停药1d耳蜗细胞即出现凋亡现象(原位缺口末端标记法阳性细胞数:柯蒂氏器0.69±0.57,螺旋神经节1.22±0.51,血管纹1.01±0.67),随停药时间延长,耳蜗细胞凋亡数增多(14d组原位缺口末端标记法阳性细胞数:柯蒂氏器4.91±0.94,螺旋神经节8.84±1.35,血管纹7.39±1.63),且愈近底回愈多,愈近顶回则愈少,对照组无凋亡现象。②豚鼠卡那霉素耳慢性中毒后,随停药时间延长,听脑干反应阈值14d组为43.20±6.73,正常对照组为5.60±1.78,14d组较正常对照组明显上升(P<0.01)。结论:①卡那霉素耳慢性中毒可引起耳蜗细胞发生凋亡,细胞凋亡是豚鼠耳蜗损伤的一条途径。②耳蜗细胞凋亡可能是卡那     

对侧抑制效应对强声所致耳蜗听力功能降低的影响

背景耳声发射是了解听觉功能受损情况的敏感测量方法,而对侧抑制可改变耳蜗的功能状态. 目的了解对侧抑制效应对噪声暴露后畸变产物耳声发射( DPOAE) 听力图幅值的影响. 设计自身对照的前瞻性研究. 地点和对象在同济医科大学协和医院完成,耳科正常人 20例 40 耳,男 9例,女 11例. 干预对受试者以宽带噪声为对侧抑制声 (60 dB SPL), 105 dB SPL 2 kHz窄带噪声暴露 10 min,以 L1=70 dB SPL,L2=60 dB SPL,f2/f1=1.21的初始音进行 DPOAE听力图测试观察. 主要观察指标 DPOAE幅值. 结果噪声暴露可引起暴露声以上各频率测量点的 DPOAE 2f1-f2反应幅值显著性降低 (t=5.468,4.984,4.796,5.966,3.546,P均 < 0.05),以暴露声半倍频 f2频率处 (f2=3kHz)降低最为显著 (t=4.984,P=0.000 02). 而对侧抑制效应主要表现在 2 kHz 测量点,使此处幅值显著降低 (t=3.148,P=0.003).暴露后存在对侧抑制与否对 2～ 6 kHz f2频率处的 2f1-f2幅值改变具有明显影响( t=5.452,4.037,4.798,5.964,3.564,P 均 < 0.001). 结论 DPOAE听力图测试具有较好的频率特异性和高度敏感性,能特异而敏感地反映出对侧抑制和噪声暴露的效应.对侧抑制效应明显增加了 DPOAE测量对强声所引起的耳蜗功能降低的敏感性.     

凯时治疗突发性耳聋47耳

目的:评价凯时对突发性耳聋的治疗效果.方法:将89例突发性耳聋患者分为两组,45例47耳采用凯时10μg静脉滴注,每天1次,联合高压氧治疗为凯时组;44例46耳采用右旋糖酐、高压氧治疗为对照组,两组治疗时间均为14 d.结果:凯时组总有效率高于对照组(95.7%vs 73.9%,P＜0.05).结论:凯时联合高压氧治疗突发性耳聋耐受性好、总有效率优于常规治疗.     

川芎嗪拮抗庆大霉素耳毒性作用的实验研究

目的探讨川芎嗪拮抗庆大霉素耳中毒有效。方法采用脑干听觉诱发反应（ABR）检测听阈值、还原型尼克酰胺腺嘌呤二核甘酸—黄递酶（NADPH－d）酶组化法检测一氧化氮合酶NOS1活性。结果联合用药组可以显著降低应用庆大霉素而增高的ABR阈值（P<0.01)及NOS活性(P<0.01),且NOS活性增高与ABR阈值增高存在正相关关系.结论川芎嗪通过减低庆大霉素耳中毒蜗NOS活性,ABR阈值拮抗其耳毒性     

噪声性听损伤者听性脑干诱发电位的变化特点

目的：观察噪声性听损伤者听性脑干诱发电位（auditory brainstem response，ABR）的变化特点。方法：对接触噪声作业的47例工人进行纯音测听（pure tone audiometry，PTA）和ABR测试；依PTA正常者和4、3、2kHz处的听力受损者分为4组：对各组的ABR结果进行比较分析。结果：（1）随听力损失频率和程度的增加，逐渐出现低声强Ⅴ渡潜伏期延长、高声强Ⅰ波的异常，继之伴Ⅲ波、Ⅴ波的异常，同时伴Ⅴ渡反应阈的逐渐上升。（2）仅有4kHz受累的轻度噪声性听力损失者．主要表现为低声强的Ⅴ波潜伏期延长和半数耳高声强的Ⅰ波异常。结论：（1）噪声性听损伤的ABR变化反映了声损伤始于外毛细胞，逐渐累及内毛细胞、听神经和脑干听觉通路的病变过程。（2）低声强的Ⅴ波潜伏期延长和高声强的Ⅰ波异常系轻度噪声性听损伤ABR的主要异常表现；对于可疑噪声性听损伤者在ABRV波阁值正常时。还应观察其阈值处潜伏期，并结合其他听力学检查结果才能作出合理判断。     

青海东部高原地区人群的扩展高频测听结果分析

背景研究表明扩展高频测听可以反映耳蜗的早期病变,对监测耳毒性听力损失,老年性听力减退,噪声性听力减退等有重要价值.目的了解无工业噪声污染地区居民的扩展高频听力状况、探讨扩展高频测听对早期发现噪声性聋的敏感性,为噪声性聋的早期防治提供参考依据.设计以正常人群为研究对象,横断面调查,观察对比研究.单位由南京大学医学院附属鼓楼医院耳鼻咽喉科、解放军第四军医大学附属西京医院耳鼻咽喉科与德国吉森大学医学院听觉研究中心合作进行.对象2001-05/2002-01在青海省高原地区的无工业噪音污染区选择受试者共计300例,进行高频测听为主的听力检测.男174例,女126例.按年龄分为6～12岁的儿童组和13～30岁的青少年组,同时在南京市选择年龄、性别相匹配的健康人300例作为对照组.方法两组经过筛选程序入选后均进行高频测听为主的全套听力检测及个人史的问卷调查.将两组的0.25～16 kHz的各相对频率听阈值进行样本均数的显著性t检验,观察两组扩展高频听阈的差异性.主要观察指标两组0.25～16 kHz听阈的差异性.结果低频及语言频率上的听阈两组之间差异无显著性意义,随着频率的递增,高频阈值升高,测得听阈的可能性减小.但在6 kHz以上的扩展高频上,实验组听阈在个别频率上显著高于对照组.(P＜0.05);但两组中儿童组与青少年组的扩展高频听阈在同一频率上的出现率差异均无显著性意义.流行病学调查结果说明无噪音污染区人群的听力较之对照组实际上已经有了不易察觉的早期损伤,结论脉冲噪声对听力的损伤首先从10～20 kHz开始,其变化是从20 kHz向10 kHz处发展.该地区人群接触脉冲噪声所致的听力微损伤造成了扩展高频听阈的升高.此时如不加以防护,将逐渐过度到语言频率,听力损失则更严重.因此扩展高频测听对早期发现噪声性聋具有一定的帮助.     

甲泼尼龙琥珀酸钠耳后注射治疗突发性耳聋的疗效观察

[目的]探讨甲泼尼龙琥珀酸钠耳后注射治疗突发性耳聋的疗效.[方法]选择突发性耳聋患者82例,随机分为观察组(42例)和对照组(40例),对照组给予改善循环、营养神经药物治疗以及高压氧舱治疗,观察组在此基础上给予耳后注射甲泼尼龙琥珀酸钠治疗,10 d为一疗程,治疗一个疗程后,比较两组治疗效果.[结果]观察组总有效率为80.95%(34/42)显著高于对照组的57.50%(23/40),差异具有统计学意义(χ2=5.317,P<0.05);观察组治疗后中、低频区听阈值提高值显著高于对照组,差异具有统计学意义(P<0.05),但两组高频区治疗后听阈值提高值比较,差异无统计学差异(P>0.05);观察组听力改善与纯音听阈测定分型情况的有效率均高于对照组,但差异均无统计学意义(P>0.05).[结论]常规药物加甲泼尼龙琥珀酸钠耳后注射治疗突发性耳聋效果明显优于单纯常规药物治疗,对改善低中频区听力有良好疗效.     

The recovery characteristics of soft tissues following repeated loading

Pressure relief at the patient support interface is important to avoid tissue breakdown by ischemia, particularly with debilitated subjects. However, there are still few guidelines to indicate the level of relief required for specific tissue areas. This paper examines the nature of the tissue recovery to repeated loading in compression. Loading was produced by (1) external application using an experimental system attached to the sacrum and (2) ischial support on a dynamic cushion. In both cases, the interface pressures applied for a prescribed time were related to changes in transcutaneous gas tension, the latter being an index of tissue viability. Results indicate two distinct responses to repeated loading. The normal response provides rapid and complete tissue recovery to unloaded values of transcutaneous oxygen tension. This was observed with all normal subjects and some of the debilitated subjects. There was also a group of debilitated subjects who demonstrated impaired and delayed tissue recovery. It is proposed that they are at most risk of developing tissue breakdown.     

Pharmacokinetics of cinoxacin in elderly patients following repeated oral administration

Cinoxacin is an antibacterial drug belonging to the quinolone class used in the treatment of urinary tract infections due to common gram-negative pathogens. Considering the high frequency of urinary tract infections in elderly people where aging represents a physiopathological condition frequently requiring an adjustment of the dosage regimen, the pharmacokinetic behaviour of cinoxacin (500 mg/12 h) in aged patients was investigated to find out if age-dependent differences may be established. The main differences detected were a shift to 4 h of the Tmax and a partly reduced clearance in comparison with data referred to younger people. On the other hand the findings showed that no accumulation occurred. High urinary concentrations of cinoxacin, exceeding the MICs for most urinary tract pathogens were found up to the 12th hour after administration.     

A fatal case of repeated ventricular fibrillation due to torsade de pointes following repeated administration of metoclopramide

Although metoclopramide has many adverse effects, torsade de pointes (TdP) is rare. We describe a fatal case of repeated ventricular fibrillation due to TdP following repeated administration of metoclopramide. Administration of multiple doses of metoclopramide over a short time to a patient with risk factors for TdP should be avoided.     

Factors influencing function and recovery following hip repair surgery

PURPOSE: Despite advances in surgical techniques and rehabilitation, many patients or individuals fail to regain their prior functional ability following hip repair surgery. The purpose of this study was to evaluate the most commonly cited predictors of successful recovery: age, balance, gender, fatigue, fall efficacy, pain, comorbidity, complications following surgery, cognitive ability, depression, and functional status prior to surgical intervention. SAMPLE: Seventy-three persons following hip repair surgery were evaluated in an inpatient rehabilitation program and 3 months following discharge. METHODS: This is a secondary analysis of data used in a previous study. The data analyzed in this study were from a study evaluating the impact of post surgical video-based education. RESULTS: Balance and cognitive ability were the best predictors of functional ability 3 months following discharge from a rehabilitation setting. As to return to functional ability following discharge, balance, cognitive status, and prior functional ability were the best predictors. Men reported higher functional levels 3 months following discharge and were more likely to return to their presurgical functional level. DISCUSSION/RECOMMENDATIONS: The significant influence of balance and fatigue on functional ability highlights the need for interventions aimed at improving balance and reducing fatigue as persons recover following hip repair surgery.     

Electrical and mechanical recovery of cardiac function following out-of-hospital cardiac arrest

Background

Compression pauses may be particularly harmful following the electrical recovery but prior to the mechanical recovery from cardiopulmonary arrest.

Methods and results

A convenience sample of patients with out-of-hospital cardiac arrest (OOHCA) were identified. Data were exported from defibrillators to define compression pauses, electrocardiogram rhythm, PetCO2, and the presence of palpable pulses. Pulse-check episodes were randomly assigned to a derivation set (one-third) and a validation set (two-thirds). Both an unweighted and a weighted receiver–operator curve (ROC) analysis were performed on the derivation set to identify optimal thresholds to predict ROSC using heart rate and PetCO2. A sequential decision guideline was generated to predict the presence of ROSC during compressions and confirm perfusion once compressions were stopped. The ability of this decision guideline to correctly identify pauses in which pulses were and were not palpated was then evaluated. A total of 145 patients with 349 compression pauses were included. The ROC analyses on the derivation set identified an optimal pre-pause heart rate threshold of > 40 beats min⁻¹ and an optimal PetCO2 threshold of >20 mmHg to predict ROSC. A sequential decision guideline was developed using pre-pause heart rate and PetCO2 as well as the PetCO2 pattern during compression pauses to predict and rapidly confirm ROSC. This decision guideline demonstrated excellent predictive ability to identifying compression pauses with and without palpable pulses (positive predictive value 95%, negative predictive value 99%). The mean latency period between recovery of electrical and mechanical cardiac function was 78 s (95% CI 36–120 s).

Conclusions

Heart rate and PetCO2 can predict ROSC without stopping compressions, and the PetCO2 pattern during compression pauses can rapidly confirm ROSC. Use of a sequential decision guideline using heart rate and PetCO2 may reduce unnecessary compression pauses during critical moments during recovery from cardiopulmonary arrest.     

Studies on nephrotoxicity following a single and repeated administration of cis-diamminedichloroplatinum (CDDP) in rats

Nephrotoxicity following a single and repeated administration of cis-diamminedichloroplatinum (CDDP) was investigated in male Wistar rats. When CDDP in a single dose of 4 mg/kg was injected i.p. into animals, serum creatinine (Cr) and blood urea nitrogen (BUN) reached a peak after 4 days and returned to the initial levels within two weeks. Nephrotoxicity of CDDP was dose-dependent, and related to the route of administration in the following order of i.p.s.c.i.v. When CDDP (4 mg/kg) was injected i.p. repeatedly at intervals of three weeks, a decrease in nephrotoxicity was observed after the 2nd injection of drug. This decreased nephrotoxicity was detected as early as a week after the 1st injection. Following the 3rd injection, nephrotoxicity showed an accumulative pattern. The change in the route of administration or its regimen did not alter the pattern of CDDP-induced nephrotoxicity. Decreased nephrotoxicity after the 2nd injection of the drug seems to be interesting from viewpoint of a host defense response.     

Symptomatic and hemodynamic recovery following dobutamine stress echo: benefit of low-dose esmolol administration

Objectives: We studied the use of esmolol in patients experiencing minor side effects of palpitations, anxiety, nervousness, and tremors associated with dobutamine stress echocardiography. Background: Dobutamine stress echocardiography is frequently used in the assessment of coronary artery disease. Esmolol administration may enhance patient comfort. Methods: Sixty consecutive patients who experienced minor side-effects during dobutamine stress echocardiography were given 0.3 mg/kg esmolol intravenously in the recovery period and compared retrospectively to sixty consecutive controls who underwent dobutamine stress echocardiography, who did not receive esmolol, during the same time period. Both groups were matched for age, ejection fraction, and peak dose of dobutamine. Heart rate and blood pressure were assessed during and after dobutamine administration. Results: Both groups had similar baseline blood pressure (mmHg) (142 ± 19/72 ± 14 vs 139 ± 20/72 ± 14) and heart rate (beats per minute) (75 ± 14 vs 75 ± 17) (esmolol and control respectively, p=ns), but peak heart rate was higher in the esmolol group (126 ± 14 vs. 116 ± 14, p<0.01). In the group who received esmolol, symptomatic relief paralleled the statistically significant decrease in heart rate which occurred within 1 minute of esmolol administration (99.7 ± 15.3 vs 108.5 ± 13.1 p<0.0001); the heart rate in the esmolol group remained significantly lower than the control group for 5 minutes following esmolol administration (92.0 ± 10.3 vs 96.7 ± 11.8 p<0.05). As a percentage of peak heart rate the esmolol group remained significantly lower than the control for 7 minutes (74% vs 80% p<0.05). Esmolol induced a significant reversal of dobutamine-induced diastolic hypotension (diastolic blood pressure at peak 66 ± 17 vs 8 min recovery 70 ± 12, p<0.03) that was not seen in controls (diastolic blood pressure at peak 64 ± 18 vs 8 min recovery 65 ± 14, p=ns). Systolic blood pressure and heart rate remained elevated in both groups 8 min into recovery compared to baseline, suggesting persistent dobutamine effect beyond the expected 2 min pharmacologic half-life of dobutamine. No side-effects from esmolol were seen despite it being used in 9 patients with EF $lt; 35%. Conclusions: Esmolol is effective and well tolerated for the management of dobutamine-related minor side-effects. The mechanism of benefit, in addition to heart rate reduction, may involve a reversal of dobutamine- induced diastolic hypotension. Blood pressure and heart rate recovery are slower than expected from previously published pharmacokinetic data.     

延长卡那霉素外环境持续存在时间鸡基底乳头的超微形态变化

背景：卡那霉素延长施药时鸡听功能的变化已有少数文献报道．但关于其耳蜗超微形态变化的研究极少。目的：观察鸡耳中毒后卡那霉素外环境持续存在时鸡基底乳头的超微形态变化。设计：完全随机设计，对照观察。单位：上海第二医科大学附属新华医院。材料：实验于2001-06／2003-08在上海第二医科大学附属新华医院完成。选择新生罗曼鸡78只，雌雄不拘，由上海归兴种鸡厂提供。方法：将3d龄罗曼雏鸡连续肌注卡那霉素200mg／（kg&;#183;d）lOd后随机分组：①经典施药组：不再施与药物，分别于施药完毕后1，3，7，10，15d时处死，每时相组6只。②延长施药组：继续按200mg／（kg&;#183;d）肌注卡那霉素，分别于连续施药13，17，20，25，30d时处死，每时相组6只。③对照组：不施与任何药物。设3，13，33d龄3组，每时相组6只。处死时分别与初次施药开始时、连续施药10d及30d的实验动物同龄。各时相组分别行听性脑干反应检测及基底乳头扫描电镜观察，观察耳蜗超微形态变化、阈值、阈值时Ⅰ波潜伏期及振幅变化。主要观察指标：①鸡耳蜗超微形态变化。②鸡听性脑干反应检测结果。结果：78只罗曼鸡全部进入结果分析，无脱失。①听性脑干反应检测结果：连续施药20d内，鸡听性脑干反应阈值损失及恢复与施药10d即停药组非常相似；施药20d后，鸡听性脑干反应阈值再次明显升高。②扫描电镜结果：对鸡施与卡那霉素10d完毕时，鸡基底乳头近端40％区域毛细胞完全破坏消失；其后虽继续施药，毛细胞已开始再生修复损伤，连续施药20d内基底乳头再生毛细胞之发育成熟与施药10d即停药组基本一致；连续施药25d时，基底乳头近半端部分再生毛细胞再次受损，连续施药30d时，大部分再生毛细胞破坏消失。结论：鸡卡那霉素耳中毒后，卡那霉素的持续存在明显阻止了鸡基底乳头损伤的完全修复。