Serial in vivo MR tracking of magnetically labeled neural spheres transplanted in chronic EAE mice.

Neural stem cell (NSC) transplantation has been shown to attenuate the severity of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Central to the future success of NSC transplantation in MS is the ability of transplanted cells to migrate from the site of transplantation to relevant foci of disease. Using magnetically labeled mouse neurospheres and human embryonic stem cell (hESC)-derived neurospheres, we applied serial magnetic resonance imaging (MRI) to assess the biodynamics of transplanted cell migration in a chronic mouse EAE model. Magnetic labeling did not affect the in vitro and in vivo characteristics of cells as multipotential precursors. Cell migration occurred along white matter (WM) tracts (especially the corpus callosum (CC), fimbria, and internal capsule), predominantly early in the acute phase of disease, and in an asymmetric manner. The distance of cell migration correlated well with clinical severity of disease and the number of microglia in the WM tracts, supporting the notion that inflammatory signals promote transplanted cell migration. This study shows for the first time that hESC-derived neural precursors also respond to tissue signals in an MS model, similarly to rodent cells. The results are directly relevant for designing and optimizing cell therapies for MS, and achieving a better understanding of in vivo cell dynamics and cell-tissue interactions.     

化疗药物性静脉炎及渗漏损伤的动物实验模型研究概况

化疗药物性静脉炎及渗漏损伤的动物实验模型是研究体内化疗药物性静脉炎及渗漏损伤的发病机制和评价各种治疗方法的重要条件。化疗药物性静脉炎及渗漏损伤的实验研究进展缓慢,其主要原因是缺乏理想的动物模型。依文献报道,化疗药物性静脉炎模型主要以大白兔耳缘静脉注射长春瑞滨等化疗药物为多见,化疗药物渗漏损伤模型主要以大鼠及大白兔背部皮下注射盐酸阿霉素等化疗药物为多见。文章就近年来常用的一些化疗药物性静脉炎及渗漏损伤的动物模型综述如下。     

腹腔镜辅助胃底贲门癌根治术：附22例报告

目的探讨腹腔镜辅助下行D2式胃底贲门癌根治术的临床效果。方法回顾性分析3年间行腹腔镜辅助下胃底贲门癌根治术22例患者的临床资料。全组均行腹腔镜辅助下近端胃大部切除术。结果无中转开腹,平均手术时间188(162~270)min。术中平均出血182(100~260)mL。淋巴结清扫18.6(10~32)枚。术后患者平均胃肠道功能恢复时间78(48~140)h。1例肿瘤侵犯食管下段的患者术后发生吻合口瘘,经留置空肠营养管、抗炎、充分引流等处理后4周痊愈。无手术死亡。全组术后随访1~37个月,平均9.2个月,无复发转移病例。结论腹腔镜辅助下行D2式胃底贲门癌根治术方法可行,效果好,具有视野清晰、创伤小、出血少、恢复快等优点。     

Comparison of Marker Intervals and Number of Sib Pairs Used for Linkage Analysis on Simulated Nuclear Family Data

Using a two‐stage global scan design, we analyzed general population replicates 1 and 42 of the Genetic Analysis Workshop (GAW) 12 simulated data set using three methods: revisited Haseman‐Elston (HER), maximum likelihood variance estimation (ML), and variance components (VC). Three marker densities, 5‐, 10‐, and 15‐cM intervals, were examined in the first‐stage scan. We found that the 10‐cM interval appears to be the most cost‐effective approach in genotyping without sacrificing power when using a first stage significance level of 0.01. Subsequently, we performed the second‐stage scan at 1‐cM intervals for those putative positive regions identified in the first‐stage scan at a significance level of 0.01. We also compared the power to detect linkage using different numbers of sib pairs for a genome‐wide scan at a 10‐cM interval and found that power decreases nonlinearly as the number of sib pairs decreases. © 2001 Wiley‐Liss, Inc.     

母体钙代谢与补钙对妊娠的影响

妊娠期缺钙严重影响母婴的安全健康 ,其原因是由于妊娠期母体钙代谢发生变化 ,使母体血清游离钙离子浓度降低 ,血清铅浓度增高。有关研究表明 ,母体缺钙导致血铅竞争性过高 ,使胎儿身长、体重均小于胎龄儿 ,胎儿宫内发育迟缓的发生率增高 ,甚至发生早产、死胎等。同时发现血清钙离子可能对内源性一氧化氮合成释放起调节作用 ,而内皮素是最强的缩血管物质之一 ,母体补钙可调节一氧化氮与内皮素的平衡 ,从而降低妊高征的发生率。因此孕期补充钙剂是非常重要的。     

Development of specificity in corticospinal connections by axon collaterals branching selectively into appropriate spinal targets

Corticospinal projections in adult rodents arise exlusively from layer V neurons in the sensorimotor cortex. These neurons are topographically organized in their connections to spinal cord targets. Previous studies in rodents have shown that the mature distribution pattern of corticospinal neurons develops during the first 2 weeks postnatal from an initial widespread pattern that includes the visual cortex to a distribution restricted to the sensorimotor cortex. To determine whether specificity in corticospinal connections also emerges from an intially diffuse set of projections, we have studied the outgrowth of corticospinal axons and the formation of terminal arbors in developing hamsters. The sensitive fluorescent tracer 1, 1′, dioctadecyl-3, 3, 3′, 3′-tetramethylindocarbocyanine perchlorat (DiI) was used to label corticospinal axons from the visual cortex or from small regions of the forelimb or hindlimb sensorimotor cortex in living animals at 4–17 days postnatal. Initially axon outgrowth was imprecise. Some visual cortical axons extended transiently beyond their permanent targets in the pontine nuclei, by growing through the pyramidal decussation and in some cases extending as far caudally as the lumbar enlargement. Forelimb sensorimotor axons also extended past their targets in the cervical enlargement, in many cases growing in the corticospinal tract to lumbar levels of the cord. By about 17 days postnatal these misdirected axons or axon segments were withdrawn from the tract. Despite these errors in axon trajectories within the corticospinal tract, terminal arbors branching into targets in the spinal gray matter were topographically appropriate from the earliest stages of innervation. Thus visula cortical axons never formed connections in the spinal cord, forelimb sensorimotor axons arborized only in the cervical enlargement, and hindlimb cortical axons terminated only in the lumbar cord at all stages of development examined. Corticospinal arbors formed from collaterals that extended at right angles from the shafts of primary axons, most likely by the process of interstitial branching after the primary growth cone had extended past the target. Once collaterals extended into the spinal gray matter, highly branched terminal arbors formed within 2–4 days, beginning at about 4 and 8 days postnatal for the cervical and lumbar enlargements, respectively. These results show that specificity in connectivity is achieved by selectivty growth of axon collaterals in to appropriate spinal targets from the beginning and not by the later remodeling of intially diffuse connections. In contrast, errors occur in the initial outgrowth of axons in the corticospinal tract, which are subsequently corrected. Copyright © 1994 Wiley-Liss, Inc.     

精子尾部低渗肿胀试验、DNA荧光染色有效精子计数在精液分析中的意义

本文对１６０名有正常生育力的男性精液标本同时进行了精子尾部低渗肿胀率（ＨＯＳ）、精子头部ＤＮＡ荧光染色的有效精子计数（ＥＳＣ）、前向运动精子百分率（ＰＭＳ）、活动精子百分率（ＭＳ）的检测，分析它们之间的一致性。结果发现：ＨＯＳ与ＰＭＳ或ＭＳ间的符合率分别为７４％与８８％；ＥＳＣ与ＰＭＳ或ＭＳ间的符合率分别为６３％与６６％；ＥＳＣ与ＨＯＳ间的符合率为６７％。提示ＨＯＳ或ＥＳＣ可从不同角度去反映被测精子的生育力。     

肝硬化患者的脑电活动地形图

对２０例无临床肝性脑病的失代偿期肝硬化患者进行脑电活动地形图（ＢＥＡＭ）检查，并与３３例正常人作对照，以探讨亚临床肝性脑病（ＳＨＥ）的诊断价值。结果表明，２０例肝硬化患者中，ＢＥＡＭ正常５例，轻度异常５例，轻￣中度异常５例，中度异常５例，总异常率为７５％（１５／２０）。ＢＥＡＭ异常的分布特点以弥漫性分布为主要表现，主要为慢频域（δ．θ．δ＋θ／α＋β）活动增强，Ｚ值增高，只有３例波及α频域。提示：     

搭建体验式沟通平台提高大学生人际交往能力

在生活节奏不断加快，竞争激烈的当今社会，大学生群体中不同程度地存在人际交往困难，影响了各种适应社会需求和自我发展能力的培养。通过搭建体验式沟通平台，形成一种团结友爱、朝气蓬勃的氛围，将有利于大学生形成和发展健康的个性品质，提高大学生的人际交往能力。     

血压变异与心率变异及心电异常相关性分析

目的：研究血压变异(BPV)与心率变异(HRV)及心电图(ECG)异常相关性，方法：对157例未经治疗的早期高血压患者及167例未服过影响血压及心率药物的正常人，进行BPV、HRV及ECG异常的相关分析，各种数据在同一时刻得到，结果：当血压昼夜节律消失(非杓型)，BPV及HRV不正常，ECG异常明显高于其他组，当高血压患者血压昼夜节律存在时HRV各项指标接近正常，ECG异常率较低，HRV降低与血压负荷升高呈明显正相关，与心电异常也呈明显正相关，结论：对高血压治疗的目的。不仅仅是降压，还应尽量恢复昼夜血压的规律性，降低夜间血压负荷，调节植物神经功能，对于血压正常的患者。血压昼夜节律消失也应投以关照给予植物神经功能调节，达到或降低靶器官损伤或延缓靶器官损害的目的，提高患者的生活质量。