组织学实验课教学方法的探讨

目的　 探讨组织学实验课的教学方法 ,提高教学质量。方法　 在组织学实验课上 ,分别采用幻灯讲解、放映电视录像等方法对学生进行辅导 ;要求学生分别做绘镜下实像图、模式图、填图作业 ,在此基础上 ,组织学生进行讨论 ,并列表调查学生对上述 3种作业和 2种辅导的反映。结果　 赞成幻灯讲解辅导的人数 ( 71 % )显著地多于赞成放电视录像辅导的人数 ( 2 9% ) ,具有显著性差异 ( P<0 .0 0 1 )。 61 %的学生认为 ,在节约时间、检查发现学习的薄弱环节、增加复习面、调动学习积极性等方面 ,填图优于绘图。赞成做填图作业的人数 ( 94% )显著地多于赞成做绘图作业的人数 ( 4 % ) ,差异显著 ( P <0 .0 0 1 )。结论　 在目前的条件下 ,作为组织学实验课上的集体辅导 ,电视录像并不能完全代替幻灯讲解 ;让学生做填图作业 ,在节约时间、调动学习积极性、发现学习的薄弱环节、加深学习印象、增加复习的广度等方面明显地优于做绘图作业 ,值得在教学中推广。     

Intra-Operative Direct Electrical Stimulations of the Central Nervous System: The Salpêtrière Experience With 60 Patients

Indications of surgical treatment for lesions in the central nervous system depend on the risk of a definitive neurological deficit, related to the benefit of resection. Detection of eloquent areas is then necessary because of major individual variability. Neuro-imaging functional techniques are in development and are beginning to be efficient for cortical sensorymotor mapping, but still lack sensitivity and specificity for language mapping, and remain unable to give real-time data during surgery and to perform sub-cortical mapping. The more precise and reliable method of functional mapping is represented by the intra-operative direct electrical stimulations (DES), which allow identification and preservation of essential pathways for motricity, sensibility and language, at each level of the central nervous system (cortico-subcortical). We report our experience of DES in the surgery of tumours and vascular malformations located in supra-tentorial brain eloquent areas, with a consecutive series of 60 patients operated on under general or local anaesthesia, from November 1996 until May 1999 in our department at La Salpêtrière Hospital. Presenting symptoms in the 60 subjects (39 males, 21 females, mean age: 45 years) were seizures in 37 cases with normal clinical examination, and mild neurological deficit in 29 cases. MRI showed 60 supra-tentorial brain lesions: 30 precentral, 12 postcentral, 14 perisylvian in the dominant hemisphere, 4 deep-seated. All subjects underwent surgical resection using DES, with supratentorial cortico-subcortical mapping under general anaesthesia for motor areas detection in 43 cases and under local anaesthesia for sensori-motor and/or language tasks in 17 cases. The final histological diagnosis was 44 gliomas (31 low-grade and 13 high-grade), 9 metastasis, 3 cavernomas, 4 arteriovenous malformations (AVM). Resection was total or subtotal in 52 cases (87%) and partial in 8 cases (13%). 29 patients had no post-operative deficit, while the other 31 patients were impaired post-operatively, with in all cases, except 3, a complete recovery delayed for 15 days to 3 months (overall morbidity: 5%). The median follow up was 14 months. Intra-operative direct electrical stimulations of the central nervous system constitute a reliable, precise and safe method, allowing the realization of a functional mapping useful for all operations of lesions located in eloquent areas. This technique allows a minimization of definitive post-operative neurological deficit, and concurrently an improvement in the quality of resection.     

Subthalamic influences on the cardiorespiratory functions in the cat

The electrical stimulation of the subthalamic nucleus (STN) caused a conspicuous increase in arterial blood pressure (BP), heart rate (HR) and respiratory rate (RR) in freely moving cats. The pulse pressure (PP) increased significantly following an initial decrease at the beginning of the 10 s long stimulation. A rebound bradycardia occurred after switching off the stimulation. Cardiorespiratory responses might be elicited also during ketamine-induced anaesthesia. The BP responses reduced highly under the blockade of the alpha(1)-adrenergic receptors. The neurotoxic lesions of the ipsilateral globus pallidus caused no significant alterations in the cardiorespiratory responses to STN stimulation. It is concluded that, besides its role in the motor control, STN is also involved in adjusting the cardiorespiratory functions to the somatomotor activity.     

Effect of d-amphetamine on prepulse inhibition of the startle reflex in humans

Rationale: Prepulse inhibition of the startle reflex (PPI) is attenuated in animals after administration of d-amphetamine and other drugs that stimulate mesolimbic dopamine activity. Objective: The aim of the present study was to evaluate the effects of d-amphetamine (20 mg) on a variety of psychophysiological and subjective measures, including PPI, in humans. Method: Thirty-six participants (18 women) participated in a double-blind, placebo controlled, repeated measures study. In one session, participants received d-amphetamine (20 mg) orally, and in the other session, participants received an identical appearing placebo. Participants were assessed at 60, 90, and 120 min after ingestion with a 5-min block of startle trials (six control trials and six prepulse trials) followed by subjective measures of stimulation and mood. Results: d-Amphetamine increased subjective measures of stimulation and euphoria, attenuated PPI, and increased heart rate, relative to placebo treatment. Conclusions: The effect of d-amphetamine on the subjective measures was substantial and consistent over time, while the effect on PPI was only observed at 90 min after ingestion, and the effect on heart rate was limited to 90 and 120 min after ingestion. Received: 22 June 1998/Final version: 23 November 1998     

Electric and magnetic fields (EMF): What do we know about the health effects?

Because we use electric power throughout our homes and workplaces, we are all subject to electric and magnetic fields (EMF) that are created by the voltages and currents present in electrical conductors and electrical equipment. Interest in the health effects of electric-power EMF has been motivated by several epidemiologic studies showing weak associations between surrogate measures of low-level EMF exposure and both childhood cancers and adult cancers. Due to the ubiquitous presence of electric power, the public health implications of this association are potentially very significant; however, good evidence for a causal relationship between exposure to EMF and any health effect has not been found. Yet, uncertainty, plus the suggestive epidemiologic findings, have fueled public anxiety and media attention. To put this potential health threat into perspective, it is important to consider the strength of the epidemiology, the availability of supporting animal studies, and mechanistic or biophysical information about the interaction of EMF with matter. Any discussion of steps that might be taken to avoid potential EMF health-effects needs to incorporate a perspective on how hypothetical EMF risks relate to other hazards to life and health.Work presented at the 23rd Congress on Occupational and Environmental Health in the Chemical Industry (Medichem 1995) The Chemical Industry as a Global Citizen - Balancing Risks and Benefits, 19-22 September 1995, Massachusetts Institute of Technology, Cambridge, Massachusetts     

Blood pressure changes modify the release rates of catecholamines in the intermediate nucleus of the solitary tract

Summary In anaesthetized cats, the intermediate aspect of the nucleus of the solitary tract (NTS) was bilaterally superfused with artificial CSF through push-pull cannulae. The release of the endogenous catecholamines dopamine, noradrenaline and adrenaline was determined in the superfusates radioenzymatically. Blood pressure changes were elicited by intravenous injections of drugs (noradrenaline or chlorisondamine), or electrical stimulation of the intermediate NTS with the tip of the push-pull cannula.Intravenous injections of noradrenaline (3 or 10 g/kg) elicited a rise in the arterial blood pressure which was associated with a decrease in the release rate of adrenaline in the intermediate NTS. The release rates of dopamine and noradrenaline were not influenced. The intravenous injection of chlorisondamine (3 mg/kg) lowered blood pressure and diminished the release rate of dopamine in the intermediate NTS. The release rate of noradrenaline was not modified by chlorisondamine. Electrical stimulation of the intermediate NTS contralateral to the superfused nucleus increased moderately the arterial blood pressure and decreased the release rate of noradrenaline and dopamine, while the release of adrenaline was not influenced. The findings suggest that experimentally induced changes in the arterial blood pressure by drugs injected intravenously modify the release rates of adrenaline and dopamine in the intermediate NTS so as to counteract the blood pressure change. In the intermediate NTS, release of adrenaline from adrenergic nerve terminals seems to act hypertensive. The results obtained with chlorisondamine point to a hypotensive function of endogenous dopamine in the intermediate NTS. Send offprint requests to N. Singewald at the above addressThis work was supported by the Fonds zur Förderung der wissenschaftlichen Forschung     

电阻抗断层成像硬件系统的初步研究

各种原因导致的人体重要器官的缓慢出血等是导致病人死亡或预后较差的重要原因之一,目前的医学成像技术,包括CT、MRI、PET、超声等还无法对出血的过程进行长期、连续的床旁监测和监护。电阻抗断层成像是以目标体内电阻抗的分布或变化为成像对象的一种新型成像技术,作为一种廉价的无损伤检测技术,不使用核素或射线,无毒无害,因而可以成为对病人进行长期、连续图像监护的设备。本文介绍了一个基于物理模型的电阻抗成像硬件系统(FMMU V3),包括具有32个银复合电极的物理模型、采用DDS技术的恒流激励源、高精度信号检测模块、驱动测量模式程控设置模块、数据采集模块、数字I/O模块和高精度多路电源模块。该系统基于物理模型的测量数据经100次迭加后,测量精度在小信号时为1.0%,大信号时为0.1%。采用外触发DMA方式采集一组成像数据(32 X 31个)的时间小于1秒,基本满足了基于物理模型的动态成像要求,并给出了基于物理模型的初步动态成像结果。     

Acoustical modulation of electrically evoked otoacoustic emission in intact gerbil cochlea

In order to study the interaction between mechanical-electrical and electrical-mechanical transductions of outer hair cells (OHCs) in vivo, we observed the acoustically induced changes in the electrically evoked otoacoustic emission (EEOAE). One pole of a bipolar electrode was placed in the round window niche and the other pole on the surface of the first cochlear turn in the gerbil. A microphone and a speaker were used to monitor the EEOAE and to deliver an acoustical tone, respectively. It was found that a high sound level acoustical tone enhanced the EEOAE fine structure at frequencies below the acoustical frequency, and suppressed the overall level of the EEOAE at frequencies above the acoustical frequency. In addition, the EEOAE at frequencies approximately one half octave lower than the acoustical frequencies were relatively more enhanced or showed relatively less suppression than at other frequencies. The amplitudes of these changes had a positive relationship with acoustical tone levels. Furosemide eliminated the acoustically caused EEOAE change indicating that the acoustically caused change in the EEOAE is a phenomenon of the normal cochlea. One possible mechanism for the results is that the electrically and acoustically evoked basilar membrane (BM) vibrations interact at the EEOAE generation site and change the local mechanical and electrical properties. The second possible mechanism is that the acoustical stimulus creates an impedance discontinuity at its characteristic frequency location leading to a change in the reflected electrically evoked traveling wave, which may enhance or suppress the EEOAE by the vector summation of two waves.     

系统性红斑狼疮心电图改变及中西医结合疗效分析

目的观察系统性红斑狼疮(SLE)的心电图改变特点及中西医结合治疗的临床疗效.方法对106例 SLE患者进行常规心电图检查,并对其中62例出现心电图异常改变者进行中西医结合治疗 30d.结果 44例心电图恢复正常,18例无效,总有效率70.96%.结论中西医结合治疗能有效地改善 SLE患者的心电图异常.     

电刺激迷走神经对严重烫伤大鼠的治疗作用

目的:观察电刺激迷走神经对严重烫伤大鼠平均动脉压(MAP)、心率、存活时间及存活率的影响。方法:取24只健康成年SD雄性大鼠(200-240 g),30%TBSAⅢ度烫伤,随机分为假伤组(Sham组)、烫伤组(Scald组)、迷走神经切断组(VGX组)、迷走神经电刺激组(STM组)。各组大鼠右颈总动脉置管后通过压力传导系统与心电监护仪相连,以连续监测MAP和心率变化,并记录生存状况。结果:STM组血压、心率下降趋势平缓,各时间点血压和心率明显高于Scald组和VGX组,生存时间延长,存活率高。结论:电刺激迷走神经对严重烫伤大鼠具有治疗作用。