大鼠肺动脉平滑肌细胞膜钙激活氯通道与细胞质钙的关系及意义

目的观察大鼠肺动脉平滑肌细胞（PASMCs）膜钙激活氯通道（ClCa）与细胞质钙的关系及意义。方法大鼠PASMCs获取采用急性酶分离法。荧光光度法检测细胞质内游离钙离子浓度（[Ca^2＋]i）；全细胞膜片钳技术测定PASMCs钙激活氯电流（ICl（Ca））；等长张力测定法观察ClCa阻滞剂尼氟灭酸（NFA）和Indaryloxyacetic acid（IAA-94）对大鼠肺动脉张力的影响。结果环匹阿尼酸（CPA）和苯福林（PE）均可引起[Ca^2＋]i升高；升高的[Ca^2＋]i可以引出ICl（Ca）；NFA和IAA-94可以舒张CPA、PE引起的肺动脉环收缩。结论生理条件下大鼠PASMCs的ClCa是钙依赖性的；细胞外Ca^2＋内流及细胞质内Ca^2＋释放均可激活该通道，其参与了血管活性药诱导的肺动脉收缩。     

一种基于ARM系统的多频耳声导抗测试系统的研究

目的：研究多频探测音对某些单一低频耳导抗测试所不敏感病变的鉴别（如：传导链中断，耳硬化症等）。方法：在原有单一低频SY—IA声阻抗中耳功能分析仪的基础上，重点对多频探测音产生电路、恒压声控系统、微处理器控制系统及多频声导抗及相位角检测电路进行了研究与设计。结果：运用多频耳声导抗测试系统可以分别在不同频率探测音下对正常耳、鼓膜松弛耳和听骨链中断耳进行声导抗检测和相位角检测。结论：实验结果表明，基于ARM系统的多频耳声导抗测试系统可以为某些单一低频耳声导抗测试所不敏感病变的鉴别提供进一步的临床依据。     

噪声作业工人的畸变产物耳声发射观察

目的观察畸变产物耳声发射（DPOAE）在早期发现噪声性听力损失方面的应用价值。方法对54例非噪声作业工人（对照组）和96例纯音听阈正常的噪声作业工人（噪声组）进行纯音测听和DPOAE测试，比较两组的纯音听阈、DPOAE幅值和引出率。结果①噪声组和对照组各频率纯音听闻比较，差异无显著性（P〉0．05）；②噪声组的DPOAE幅值在3kHz、4kHz、6kHz处明显下降，与对照组比较有统计学意义（P〈0．01）；③噪声组在3kHz、4kHz和6kHz三个频率处的DPOAE引出率明显降低，与对照组比较，差异有显著性（P〈0．05，P〈0．01）：结论DPOAE能早期发现噪声性听力损失。     

中度睡眠呼吸暂停低通气综合症合并高血压患者行UPPP＋舌根射频消融术治疗后动态血压及呼吸睡眠监测联合观察

目的探讨呼吸睡眠监测（PSG）及动态血压联合观察评估中重度睡眠呼吸暂停低通气综合症（OSAHS）患者行UPPP＋舌根射频消融术治疗疗效的可能性。方法对2001年11月至2007年5月间30例（愿接受舌托治疗）中度OSAHS患者行UPPP＋舌根射频消融术治疗，对比观察治疗前及治疗后6月PSG（AHI、SaO2）与24h动态血压的变化。结果UPPP＋舌根射频消融术治疗前后AHI、SaO2、24h动态血压的变化有统计学意义（P〈0．01），说明UPPP＋舌根射频消融术治疗不仅能改善试验观察对象的AHI、SaO2，而且能有效降低其昼夜平均血压。结论呼吸睡眠监测（PSG）和24h动态血压试验联合观察可作为中度OSAHS患者的疗效评价参数组合之一；UPPP＋舌根射频消融术为治疗中度OSAHS患者有效方式之一。     

不同听力损失耳听觉稳态诱发反应阈值与纯音听阈的比较

目的研究不同听力损失耳的听觉稳态诱发反应(auditory steady-state evoked response,ASSR)与纯音听阈的关系,为客观的听力评估提供指导。方法对67例(103耳)不同听力损失耳分别行ASSR与纯音测听检查,比较ASSR分别在0.5、1、24、kHz频率处的反应阈值与纯音听阈的相关性及差值。结果ASSR的反应阈与纯音听阈在0.5、1、24、kHz频率处的相关系数分别为0.84、0.83、0.89、0.91,呈极显著相关(P<0.01);ASSR的反应阈与纯音听阈在0.5、1、2、4 kHz频率处的差值在轻度耳聋组分别为(11.2±3.5)dBHL、(12.9±3.7)dBHL、(13.6±4.1)dBHL、(13.4±4.5)dBHL;在中度耳聋组分别为(3.4±4.6)dBHL,(4.9±4.3)dBHL,(6.8±5.7)dBHL,(7.1±5.6)dBHL;在重度耳聋组分别为(1.5±3.1)dBHL,(3.4±2.1)dBHL,(2.9±2.3)dBHL,(1.2±2.6)dBHL;其中轻度耳聋组的ASSR的反应阈与纯音听阈的平均差值与重度耳聋组的平均差值有统计学意义(P<0.01)。结论ASSR反应阈与纯音听阈有显著相关性,随着听力损失的加重,ASSR反应阈愈接近纯音听阈,ASSR可作为不同听力损失者客观的听力评估。     

职业性噪声性聋发病工龄的调查分析

目的了解职业性噪声暴露人员的听力状况及其剂量-效应关系,为修订国家职业性噪声性聋诊断标准提供数据支持。方法选择8小时等效连续噪声暴露人员,运用横断面调查的方法,由经过培训合格的调查人员进行问卷调查和纯音听力检查。结果排除非噪声性听力损失的影响,有效调查1001人,高频听力损失检出率为65.1%(651/1001),显著高于语频听力损失检出率(3.0%,30/1001)。言语频率平均听力损失≥26dB的阳性检出率在工龄<10年组为0.0%;高频及语频听力损失率在10年及以上各工龄组间差异无统计学意义。结论10年以下噪声暴露基本不会影响作业人员的言语频率听力;在诊断是否"职业性噪声性聋"或"听力损伤"时应考虑剂量-效应关系;建议职业性噪声性聋诊断标准中增加噪声作业工龄≥5年的要求。     

EARLY HEARING EVALUATION AFTER MICRODRILL STAPEDOTOMY

Stapedectomy is known to give good results for otosclerosis. In this study, an audiometric evaluation of patients who underwent small-opening stapedotomy has been carried out at an early stage (3 and 5 days after surgery), and 1 month after surgery. At day 5 almost 60% of the patients showed a good functional result (mean residual post-op air conduction/pre-op bone conduction gap within 5 dB). While the timing of 4 kHz recovery overlapped that of the lower frequencies, recovery for 8 kHz was evident only at day 30, and was less likely to occur than for 4 kHz.     

A Report of a Case with Pure Red Cell Aplasia Induced by Sodium Valproate

A 5-year-old girl developed pure red cell aplasia (PRCA) during sodium valproate (VPA) administration. Only four cases of VPA induced PRCA have been reported in the literature. Furthermore no precise report concerning the underlying mechanisms is available. Using a system for the clonal growth of autologous bone marrow committed erythroid stem cells (CFU-E, BFU-E) WA itself was not inhibitory for colony formation at a physiological concentration. Patient's serum and peripheral mononuclear cells collected at admission showed no inhibitory effects on erythroid progenitor cell growth. Rapid recovery from PRCA was observed after discontinuation of VPA, without immunosuppressive therapy. Our observation suggests that VPA may induce PRCA through the inhibitory effect beyond the differentiation stage of BFU-E and CFU-E in some cases.     

LH-RH analogue acts as substance P antagonist by inhibiting spinal cord vasomotor responses

Intrathecal injections of the luteinizing hormone-releasing hormone (LH-RH) analogue, [D-pGlu1-D-Phe2-D-Trp3,6]-LH-RH caused dose-dependent decreases in mean arterial blood pressure in anesthetized rats similar to those seen with [D-Pro4-D-Trp7,9]-substance P4-11. Similarly, intrathecal injections of either peptide reversed the pressor response elicited by application of kainic acid on the ventral surface of the medulla oblongata. Both analogues also had similar IC50 values (approximately 10(-5) M) for the inhibition of specific [3H]substance P binding in tissue-sections of the intermediolateral cell column. However, the LH-RH analogue failed to block substance P (SP)-induced contractions of the isolated guinea pig ileum and did not affect tail-flick withdrawal time in a thermal nociceptive test, whereas the SP analogue acted as an antagonist in both of these bioassays. These results suggest that [D-pGlu1-D-Phe2-D-Trp3,6]-LH-RH may act as an antagonist which can inhibit the sympathetic vasomotor outflow and potentially be a substance P-physalaemin (SP-P) receptor antagonist in the central nervous system but without effect on peripheral SP-P receptors.     

Effects of alternating magnetic fields and low-frequency electric currents on human skin blood flow

The influence of alternating magnetic fields on human skin blood flow was investigated. The hands of volunteers were fixed just above an induction heater and the regional skin blood flow of a fingertip was measured by a laser Doppler flowmeter. The hands were exposed to fields with flux densities of 16 mT, 32 mT and 48 mT at a frequency of 3·8 kHz. Two parameters of the laser Doppler blood flow recording were studied: the dynamic and DC components. The dynamic component did not show any particular changes following magnetic stimulation. The DC component showed a rapid decrease in blood flow in the first period after field-on at 48 mT and 32 mT. A pain sensation with muscle contraction was recognised (48 mT and 32 mT). The effect of electrical stimulation on skin blood flow was also investigated. The differences between the magnetic and electrical effects are discussed. The results suggest that the human body responds to magnetic stimulation with an escape reaction which results in an elevated vasoconstrictor tone. The change in microvascular blood flow recorded with the laser Doppler method can probably be explained by the influence of the eddy currents on the sensory receptors of the skin.