抑郁症的睡眠脑电图与人脑兴奋守恒假说

目的　探索抑郁症状与睡眠脑电图参数的相关性。方法　对 18例抑郁症和 10例正常人评定汉密尔顿抑郁评定量表 (HAMD)和检测睡眠脑电图。结果　HAMD总分与觉醒次数及REM密度分别呈显著正相关 (r分别等于 0 .4 0 8和 0 .4 4 5 ,P均 <0 .0 5 )。结论　抑郁症和正常人的白天中枢抑制与夜间中枢兴奋相关 ,从而支持人脑兴奋守恒假说。     

Mapping location of excitation during magnetic stimulation: Effects of coil position

We determined the location of excitation for different positions of a round and butterfly coil duringin vitro magnetic stimulation of cut peripheral nerves. We analyzed the conditions under which excitation occurs, either at the termination or at the peak of the field gradients (first spatial derivative of the electric field). These results were then compared to predictions about the location of excitation sites from a theoretical model of magnetic stimulation of finite neuronal structures. Excitation along a straight nerve occurred at terminations when 1) a coil was positioned close to the end of a nerve (at least one diameter length from the end), 2) a nerve ended in a finite terminating impedance much greater than the axial resistance of the nerve, 3) the induced electric field was of sufficient magnitude, pointing in a direction away from the axis of a nerve. Excitation occurred at the negative peak of the field gradients along a nerve when 1) a coil was positioned far away from the ends of a nerve, 2) there were no geometric or volume conductor inhomogeneities around a nerve, and 3) it was of sufficient magnitude. Threshold strengths for excitation at terminations were significantly lower than that for field gradient excitation and comparable to that due to geometric and volume conductor inhomogeneities.     

横向电场作用下外周神经兴奋特性的实验研究

传统的外周神经电缆方程只能描述纵向电场刺激下外周神经兴奋,实验发现在脉冲磁场诱导的横向电场作用下也可使神经兴奋,从而揭示出需要进一步对感应电场兴奋外周神经的机理进行研究。本文研究了横向电场作用下外周神经的兴奋特性,以在体的人体正中神经为例研究了横向电场作用下外周神经兴奋点的位置、刺激阈值、及刺激阈值与纤维半径的关系,以离体的蟾蜍坐骨神经为例研究了刺激阈值与作用时间的关系。实验结果验证了改进的电缆方程的有效性。实验研究成果有助于磁刺激技术的进一步发展与应用。     

Nonspecific excitatory effects of morphine: Reverse-order precipitated withdrawal and dose-dose interactions

We recently reported that, in naive mice pretreated with naloxone, morphine can cause withdrawal-like signs that seemingly are not mediated by opiate receptors. Such results were confirmed and extended here with another mouse strain. Repetitive vertical jumping could occur irrespective of injection sequence and depended on dose and dose ratio of the two drugs.     

经济转型期公立医院管理者的激励与约束机制研究概述

目的 探索在市场经济条件下对公立医院管理者有效的激励与约束机制,建立医院管理岗位的创新机制。方法 通过现场调查访问,结合文献综述、座谈法,收集数据;通过描述性统计方法、主成分分析等统计分析方法进行数据分析。结果 通过对现在公立医院管理者的激励与约束措施和意向调查分析,找出了现在公立医院管理者激励机制和约束机制中的问题,提出了在实行医院产权制度改革的基础上建立新的分配机制,建立公立医院管理者任用竞争机制,对医院管理岗位实行人力资本管理的创新机制,加强法律法规和卫生政策对医院管理者权力的约束。结论 提出了建立适应市场经济条件下医院管理者的有效激励与约束机制的运作模式。     

Excitation of rat cerebellar Golgi cells by ethanol: further characterization of the mechanism

Background: Studies with rodents suggest that acute ethanol exposure impairs information flow through the cerebellar cortex, in part, by increasing GABAergic input to granule cells. Experiments suggest that an increase in the excitability of specialized GABAergic interneurons that regulate granule cell activity (i.e., Golgi cells [GoCs]) contributes to this effect. In GoCs, ethanol increases spontaneous action potential firing frequency, decreases the afterhyperpolarization amplitude, and depolarizes the membrane potential. Studies suggest that these effects could be mediated by inhibition of the Na⁺/K⁺ ATPase. The purpose of this study was to characterize the potential role of other GoC conductances in the mechanism of action of ethanol. Methods: Computer modeling techniques and patch‐clamp electrophysiological recordings with acute slices from rat cerebella were used for these studies. Results: Computer modeling suggested that modulation of subthreshold Na⁺ channels, hyperpolarization‐activated currents, and several K⁺ conductances could explain some but not all actions of ethanol on GoCs. Electrophysiological studies did not find evidence consistent with a contribution of these conductances. Quinidine, a nonselective blocker of several types of channels (including several K⁺ channels) that also antagonizes the Na⁺/K⁺ ATPase, reduced the effect of ethanol on GoC firing. Conclusions: These findings further support that ethanol increases GoC excitability via modulation of the Na⁺/K⁺ ATPase and suggest that a quinidine‐sensitive K⁺ channel may also play a role in the mechanism of action of ethanol.     

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.     

灸刺足三里治疗难治性面瘫临床观察

目的:观察采用灸刺足三里激发“循经感传”治疗难治性面瘫的临床疗效。方法:60例患者随机分为灸刺足三里组(试验组)、常规治疗组(对照组)各30例,对照组取合谷、太冲、头维等穴,试验组在对照组取穴基础上加灸刺足三里,以患者自觉有温热感沿针体传入穴位深层为度。结果:试验组总有效率为93·3%,明显优于对照组的76·7%(P<0·05);试验组中,有循经感传者的总有效率为100·0%,明显优于无循经感传者的80·0%(P<0·05)。结论:灸刺足三里激发“循经感传”治疗难治性面瘫具有较好疗效,值得推广应用。     

Behavioural effects of thymoleptics in vervet monkeys (Cercopithecus aethiops)

Desmethylimipramine (DMI) exerts diverse quantitative effects on the gross behaviour of monkeys. Excitatory as well as sedative effects were observed, which varied according to the general animal temperament. Results resembling those obtained with DMI were observed using chlorimipramine and iprindole, although the effects of iprindole were less marked. Chlorimipramine also produced immobilization and postural change.The results are discussed in relation to behavioural effects of thymoleptics in humans, and the use of monkeys in preclinical testing of thymoleptic drugs is suggested.     

Volumes From Which Calcium and Phosphorus X-Rays Arise in Electron Probe Emission Microanalysis of Bone: Monte Carlo Simulation

Monte Carlo simulations of trajectories for electrons with initial energy of 10 keV through 30 keV were used to map the 3D location of characteristic x-ray photon production for the elements C, P, and Ca until the electrons either escaped as backscattered electrons (BSE) or had insignificant energy. The x-ray production volumes for phosphorus slightly exceed those for calcium, but both greatly exceed the volume through which BSE travel prior to leaving the sample. The x-ray volumes are roughly hemispherical in shape, and the oblate spheroid from which BSE derive occupies only the upper third to half the volume of x-ray generation. Energy-dispersive x-ray emission microanalysis (EDX) may not be secure as a method for the quantitation of BSE images of bone in the scanning electron microscope (SEM). Ca:P elemental ratios from EDX analyses may also be imperfect.