Abnormal sensorimotor integration is related to disease severity in Parkinson's disease: a TMS study.

Hyperexcitability of the motor system has been reported in Parkinson's disease (PD). We evaluate how cutaneous afferents modulate motor excitability in PD patients and whether abnormal modulation is correlated to parkinsonian symptoms. Digital stimulation causes abnormal enhancement of motor responses in patients. This effect may be one of the features of motor hyperexcitability in PD. Cutaneomotor hyperexcitability correlates with clinical scores, suggesting that abnormal processing of cutaneous inputs might contribute to the pathogenesis of parkinsonian symptoms.     

Spatial relation of the acetylcholinesterase-rich domain to the visual topography in the feline superior colliculus

Summary The superior colliculus (SC) of the cat shows a prominent compartmentalized organization at the level of its intermediate layers. The mosaic of these compartments is apparent in the pattern of acetylcholinesterase (AChE) staining. Patches of high AChE-activity are sharply set off from surrounding areas in the caudal SC while they are less distinct anteriorly. The rostral part lacks such obvious compartments. Thus, a structural reorganization apparently cuts across the topographical representations spread out in the SC. In order to test if this compartmental gradient relates to the topographic maps of the colliculus, retinotopic landmarks were visualized in the superficial layers by labeling the retinotectal pathway. In the SC ipsilateral to the eye injected with horseradish peroxidase (HRP) a paucity of labeling indicated the zone representing the ipsilateral visual half-field. Serial reconstructions of collicular sections, cut longitudinally or tangentially, revealed that the non-compartmentalized part of the intermediate layers corresponds to the representation of the ipsilateral visual half-field in the layers above, while an intricate mosaic array of compartments prevail in tectal zones related to the representation of the contralateral visual half-field.     

Adaptation to audiotactile asynchrony

Previous research has revealed the existence of perceptual mechanisms that compensate for slight temporal asynchronies between auditory and visual signals. We investigated whether temporal recalibration would also occur between auditory and tactile stimuli. Participants were exposed to streams of brief auditory and tactile stimuli presented in synchrony, or else with the auditory stimulus leading by 75 ms. After the exposure phase, the participants made temporal order judgments regarding pairs of auditory and tactile events occurring at varying stimulus onset asynchronies. The results showed that the minimal interval necessary to correctly resolve audiotactile temporal order was larger after exposure to the desynchronized streams than after exposure to the synchronous streams. This suggests the existence of a mechanism to compensate for audiotactile asynchronies that results in a widening of the temporal window for multisensory integration.     

Hemispheric control of unilateral and bilateral responses to lateralized light stimuli after callosotomy and in callosal agenesis

Normally, simple digital or manual responses to a light stimulus in the right or left visual hemifields are performed faster with uncrossed hand-field combinations than with crossed hand-field combinations. Because of the organization of visual and motor pathways, the integration of uncrossed responses is assumed to occur within a single hemisphere, whereas a time-consuming inter-hemispheric transfer via the corpus callosum is considered to be necessary for the integration of crossed responses. However, callosal transfer may be dispensable for those crossed responses which can be controlled through ipsilaterally descending motor pathways by the hemisphere receiving the visual stimulus. We investigated crossed-uncrossed differences (CUDs) in speed of simple visuomotor responses to lateralized flashes in one subject with total section of the corpus callosum and two subjects with complete callosal agenesis. We recorded the reaction times as well as the premotor times, as indicated by the electromyographic latencies of the prime movers, of three types of responses: a distal response involving a thumb flexion, a proximal response chiefly involving a forearm flexion and an axial response involving a shoulder elevation. Further, the three types of responses to a single lateralised flash were performed both unilaterally and bilaterally. The three acallosal subjects showed CUDs greatly exceeding normal values on distal responses, either unilateral or bilateral, and on unilateral proximal responses. These abnormally long CUDs stood in sharp contrast to the insignificant CUDs exhibited by the same subjects on bilateral proximal responses and on unilateral and bilateral axial responses in agreement with correspondingly insignificant CUDs reported for normal subjects. These results confirm that a callosal contribution is important for the execution of fast distal and unilateral proximal responses to a visual stimulus directed to the hemisphere ipsilateral to the responding hand. By contrast, the other types of crossed responses appear to be efficiently coordinated across the midline without the aid of the corpus callosum. This is in keeping with the hypothesis that they are governed by a bilaterally distributed motor system which is preferentially activated for the execution of symmetrical bilateral movements, employing axial and proximal limb muscles.     

Assessing accurate sizes of synaptic vesicles in nerve terminals

Chemical synaptic transmission occurs when vesicles within a presynaptic neuron fuse to the membrane and release their neurotransmitter content into the synaptic cleft, eliciting a response in the postsynaptic cell. If concentration of neurotransmitter is the same in all synaptic vesicles, the volume of the vesicle determines how much transmitter is released. Thus, variation in vesicular volume may contribute to observed variance of synaptic quantal unit size. The present study provides an approach to more fully and accurately characterize the dimensions of synaptic vesicles within a population containing varied sizes of vesicles. The methodology can be applied in a wide range of stereological problems. The approach characterizes the distribution of vesicle sizes within a population and provides a means to assess effects of experimental manipulations on vesicle dimensions. The mathematical treatments to obtain the true distribution of vesicle sizes involve extraction of the observed distribution from an enlarged population containing smaller vesicle diameters produced by sectioning of the specimens. A FORTRAN program is provided.     

集成技术在医院图书馆的应用

本文结合医院图书馆实际，采用系统集成及光驱虚拟技术，构建不同系统协同工作的网络环境，实现了多个系统功能的互通，提高了图书馆现代化管理水平及综合服务能力，解决了图书馆建设中存在的管理水平低、服务手段落后及数据库资源闲置浪费等问题。本技术对资金和技术人员紧缺的中小型医院图书馆实现网络共享光盘数据库具有现实意义。     

支气管哮喘临床教学课程整合的探索与实践

医学整合课程教学模式并不是一种新型的教学模式,它起源于20世纪50年代,已经过六十多年的不断完善和调整,目前逐步成为国内外医学院校的主要医学教学模式。整合医学教学模式坚持用整体、求实创新、动态发展、相互联系和既对立又统一的思想和观点进行教学,符合临床学习规律,是现代医学教育发展的必然趋势。我院教研室近些年来陆续在各个临床专业之间试行课程整合模式,在有限的课时内把课程内容有机整合,避免不同学科间相关教学内容和学习要点的交叉重复,提高学生学习的积极性,有利于学生提高学习效率,并形成一个连贯的知识框架,教学效果较好,同时能够促进教师教学综合能力的提高,有利于培养学生多方面的能力及综合素质。我们以支气管哮喘这一章的教学为代表,具体阐述了儿科、内科临床教学课程整合模式的实践及经验。临床教学课程整合教学效果较好,发展前景良好,但在实施和实践过程中还需要医学教育者投入更多的心血和智慧。     

A Community-Based Organization's Integration of HIV and Substance Abuse Treatment Services for Ex-Offenders

Summary

This paper explores the point of intersection of the substance abuse treatment and HIV services industries with the criminal justice system. Section I reviews the literature and “best practices” that have integrated substance abuse treatment and HIV care and prevention services for ex-offenders and which informed the development of a community-based organization's initiative, the VIP STRIVE Project. Section II presents a brief history of VIP in the context of its ability to adapt to its environment and to the changing needs of its target population, with specific reference to the development of HIV and substance abuse treatment services for members of the criminal justice population. The concluding section brings the two previous sections together by explaining how the VIP STRIVE Project can assist VIP in enhancing its capacity to integrate its substance abuse treatment and HIV services in order to improve services for this target population.     

EDITOR'S FOREWORD

No abstract available for this article.