癫痫患者经颅磁刺激的安全性观察

目的：评估癫痫患者经颅磁刺激（ＴＭＳ）的安全性。方法：以单脉冲磁刺激检测３５例癫痫患者和３０例对照组的双侧运动传导通路,依次刺激肘部,锁骨上窝,第７颈椎和运动皮质诸部位,周围段刺激间隔≥３秒,皮质刺激间隔≥１０秒,每部位刺激总数≤１２次,记录运动诱发电位（ＭＥＰ）。结果：测试过程中患者和对照组均未出现癫痫发作,随访部分患者２～４周,其测试前后的发作形式和频率未发生改变,个别患者在刺激时有短暂轻微不适;患者的皮质刺激阈强度均高于对照组,经抗癫痫治疗者增高更明显。结论：单脉冲磁刺激对癫痫患者是一种安全的电生理检测手段,可应用于研究癫痫的病理生理,指导抗癫痫药物的应用     

O2 consumption,aerobic glycolysis and tissue phosphagen content during activation of the NA+/K+ pump in rat portal vein

Oxygen consumption, lactate production and tissue contents of ATP, phosphocreatine (PCr) and lactate were measured following readdition of K⁺ to K⁺-depleted rat portal veins, in order to study the energy turnover associated with Na⁺/K⁺ pumping. During incubation in K⁺-free medium at 37° C spontaneous contractions disappeared in 10–20 min. Readdition of K⁺ (5.9 mM) after 40 min K⁺-free incubation caused hyperpolarization of the cell membrane for the first 5–10 min and then gradual depolarization with return of spontaneous action potentials and contractions by 10–20 min. During the first 4–6 min after K⁺ readdition aerobic lactate production was about doubled and then gradually returned to the original level (0.17 mol/min g) at about 20 min. The increase in glycolytic rate was prevented by 1 mM ouabain. In contrast, O₂ consumption (in K⁺-free medium, 0.38 mol/min g) rose by about 10% when K⁺ was added and this increase lasted about 5 min. By 8 min after K⁺ addition the increased glycolysis and oxidative phosphorylation had accounted for each about the same amount of extra ATP generation over that extrapolated from the steady rate before K⁺ addition. The average total increase in ATP turnover in the first 8 min was 15%. During this period there was no change in the cellular content of ATP, PCr, or extractable ADP. The results indicate that Na⁺/K⁺ pumping utilizes a relatively small share of the total energy turnover in the vascular smooth muscle but is to a large extent dependent on aerobic glycolysis and therefore a major site of carbohydrate usage.     

大学生感觉寻求人格特征与脑电诱发电位的关系

目的:研究大学生感觉寻求人格特征与脑电诱发电位的相关性.方法:测试大学生感觉寻求及MMPI人格特征,分析长潜伏期听觉诱发电位与感觉寻求人格特征的相关性,寻找感觉寻求人格特征的生物学标志,并进一步探讨感觉寻求人格特征的生物学基础.结果:1.高、低感觉寻求组轻躁狂(t=3.1)以及抑郁(t=3.62)分量表得分具有显著性差异(P均＜0.01),高感觉寻求组的抑郁得分较低,轻躁狂得分较高,而低感觉寻求组则与之相反.2.高感觉寻求者具有快速习惯化的特点(tc2=2.4,tc3=2.6,tc4=2.5,P均＜0.05).结论:1.感觉寻求人格特征呈现极端形式者(低或高)可能容易出现与抑郁、轻躁狂相关的精神问题.2.与强度依赖性相比,快速习惯化现象可能是高感觉寻求者的一个更加显著的电生理标志.     

基于内模自适应估计器的VEP信号提取新方法

本文基于确定信号和扰动和内模建立了两种视觉诱发脑电（VEP）和自发脑电（EEG）混合信号的组合状态空间模型，基于时域参数模型提出了采用迭代型推广卡尔曼滤波算法来实现VEP信号的自适应估计，最后通过临床实际应用比较分析了两种建模方法的滤波性能。     

Simultaneous Electrical and Optical Mapping in Rabbit Hearts

Local cardiac excitation is measured from either extracellular voltage (V _e ) or optical transmembrane voltage (V _m ) with fluorescent dye. We used a transparent electrode array and a laser scanner to test whether V _e and coepicentral optical V _m give equivalent excitation times during epicardial pacing and sinus beats. To help explain time differences, we estimated interrogation width/depth ratios for V _e and optical V _m with dipole and Monte Carlo models. Magnitudes of time differences between excitation measured with V _e and optical V _m during pacing were 1.9 ± 1.9 ms (n=1,112 recording pairs). Deeper interrogation for optical V _m vs V _e was indicated with sinus beats that contained a transmural propagation component. When pacing produced propagation along epicardial fibers, excitation time measured from optical V _m was later than excitation time measured with epicardial V _e When pacing produced propagation across epicardial fibers, excitation time measured from optical V _m was earlier than that measured with epicardial V _e These time differences could be attributed to deeper optical interrogation and fiber rotation with depth in ventricles. © 2003 Biomedical Engineering Society.     

视觉诱发电位P100潜伏期的临床意义

本文探讨了视觉诱发电位 (VisuallyevokedcorticalpotentialsVEP)P10 0潜伏期延长的临床意义。检测对象为临床眼科病例 ,其中视神经炎 2 5例 30只眼睛 ,多发性硬化症 15例 30只眼睛 ,青光眼 2 0例 30只眼睛。以正常人 2 5例 5 0只眼睛作为对照组。提示 :所有视神经病变P10 0潜伏期都延长 ,黄斑部正常的视神经疾病其P10 0潜伏期也延长。P10 0潜伏期的延长能够反映视神经障碍     

基于分数低阶矩的非高斯噪声中诱发电位提取新方法

诱发电位（EP）信号榆测与分析技术是临床医学诊断神经系统损伤及病变的重要手段之一。传统的EP信号提取与分离方法中，通常认为EP信号中混入的EEG等噪声是高斯分布的。近年来一些研究表明TEEG信号具有一定的非高斯特性。α-稳定分布町以更好地描述实际应用中所遇到的具有显著脉冲特性的EEG噪声。文中简要介绍了稳定分们统计特性，推导了一种适用于EP信号分离提取的新算法。计算机模拟和分析表明，这种算法是一种在分数低阶α稳定分布背景噪声条件下具有良好韧性的EP信号分离提取方法。     

颈椎损伤后手术中脊髓保护措施的效果探讨

目的探讨颈椎损伤后手术中脊髓保护措施的效果。方法强迫位下清醒/快速诱导气管插管后,部分患者行控制性降压、脱水、利尿、适度过度通气、皮层体感诱发电位(CSEP)监测;截瘫患者行双下肢弹性绷带缠裹。结果快速诱导插管较清醒插管难度明显降低(P<0.05),术后并发症减少;控制性降压明显减少术中出血量(P<0.01),显露清晰,方便椎管内操作;脱水、利尿、适度过度通气使椎管内压明显降低,硬膜、脊髓损伤减少;截瘫患者弹性绷带缠裹后,术中脊髓血供改善;CSEP监测可规避术中误伤脊髓的发生。结论颈椎手术中脊髓保护应从诱导插管、术中管理多个环节加以落实,方可获得理想的脊髓保护效果。     

新生儿脑干听觉诱发电位测定

目的：探讨新生儿脑干听觉诱发电位（BAEP）正常值。为早期发现新生儿听力障碍提供参考。方法：应用中国科技大学生物技术公司生产的NGT型脑干反应测听仪对出生1－7d的43例新生儿进行BAEP检测，以声强70dB的短声分别刺激左右耳，对其中符合正常新生儿标准的31例（63耳）检测结果进行分析，并进行统计学处理。结果：（1）BAEP出波率：70dB BHL出波率为100％。（2）波潜伏（PL）发育：Ⅰ、Ⅲ，Ⅴ波各波潜伏期与成人正常值明显不同（P＜0．0005）。（3）波间期（IPL）发育：Ⅰ－Ⅲ、Ⅲ-Ⅴ、Ⅰ－Ⅴ波间期参数与成人正常值亦有明显不同（P＜0．0005）。结论：正常新生儿BAEP参数与成人BAEP正常值明显不同，对31例正常新生儿进行检测，取得了正常新生儿BAEP参数，对诊断新生儿疾病有一定价值。     

高胆固醇血症家兔心脏单相动作电位及钙电流的特征

目的观察高胆固醇血症对家兔心脏单相动作电位及钙电流的影响。方法24只家兔分为高胆固醇饮食组和对照组各12只,分别给予高胆固醇饲料和标准饲料饲养10周后,检测血脂、心电图和室颤阈值,记录离体灌流心脏单相动作电位,并记录心室肌细胞的L型钙通道电流。结果高胆固醇饮食组兔的血脂水平明显高于对照组(P<0.01);室颤阈值(10.2±1.7)V,低于对照组的(13.9±1.3)V(P<0.05);单相动作电位复极90%的时程(MAPD90)较对照组延长并呈更明显的逆频率依赖性,在1500ms起搏时MAPD90为(348±21)ms,而对照组为(271±16)ms;心室肌细胞的L型钙通道电流密度为(14.7±0.8)pA/pF,明显高于对照组的(10.9±1.1)pA/pF(P<0.01)。结论高胆固醇血症家兔的心脏单相动作电位及心肌细胞L型钙通道电流明显改变,复极时程延长,室颤阈值降低。