海人酸致大鼠海马结构GABA_B受体亚单位表达的研究

目的:探讨海人酸诱导大鼠颞叶癫(EP)发作后2种γ-氨基丁酸(GABA)受体亚单位GABABR亚单位1a(GBR1a)和GABABR亚单位2(GBR2)在EP发生、发展中的作用。方法:运用原位杂交及免疫组化法,检测EP发作后GABABR亚单位mRNA及蛋白在海马的表达。结果:致早期CA1和CA3区2种亚单位mRNA表达持续低下后逐渐增加,DG区则暂时性下降后很快回升;而免疫反应早期却未见明显改变,随后CA1和CA3区表达处于低水平,DG区和颞叶皮质表达下降后很快恢复。结论:致后2种GABAB受体亚单位基因和蛋白表达上调为颞叶EP的内源性自我保护机制。     

快乐的脑机制研究

快乐作为情绪的重要方面,对人类的生存具有重要意义。早期关于快乐脑机制的研究将大脑奖励系统误认为是产生快乐的快乐中心,认为多巴胺是将感觉刺激转化为快乐的神经递质。最新的研究指出,产生快乐的脑环路主要包括伏核壳、脑干臂旁核和腹侧苍白球。     

急进性后极部早产儿视网膜病变的临床进程及疗效观察

目的 描述急进性后极部早产儿视网膜病变(AP-ROP)的临床进程及特征,评价视网膜光凝及冷凝对急进性后极部早产儿视网膜病变的治疗效果.方法 前瞻性、非对比性、连续性病例.2006年1月至2008年6月经检查确诊为急进性后极部ROP的患儿8例16只眼.确诊后24h内行间接眼底镜下行视网膜光凝治疗联合或不联合直视下冷凝治疗.结果 急进性后极部早产儿视网膜病变以病变大部分位于后极部1区,所有象限视网膜血管扩张迂曲,病程进展快,若不及时治疗,迅速发生视网膜漏斗状全脱离为临床特征.本组8例16只眼视网膜光凝和(或)冷凝治疗后,9只眼病变完全退化或控制,占56.2%.7只眼病情未能控制,最终发展为4b至5期视网膜病变.结论 AP-ROP进展快,预后不良,部分患儿虽经严密观察和治疗,病情仍进展.视网膜光凝和(或)冷凝治疗能控制大部分AP-ROP患儿视网膜病变的发展,挽救患儿视功能.临床上需要加强观察和随访,早发现、早诊断、早治疗是减低该病致盲率的惟一方法.     

图片学习测验在识别老年人轻微认知功能损害中的作用

目的　分析图片学习测验在识别老年人轻微认知功能损害 (MCI)中的作用。方法　选择符合MCI诊断标准的老年人 4 8例与正常对照组 5 6名完成图片学习测验、简易智能状态检查、听觉词语学习测验及多种非记忆测验。结果　图片学习测验的 3个记忆指标 (图片短时记忆、延迟记忆和学习记忆 )在MCI与正常对照组之间有非常显著的差异。已经给出这三个图片记忆指标区分MCI与正常老年人的划界分、敏感性和特异性。结论　图片记忆操作简便、信度和效度好 ,可以作为临床医师筛选MCI的有效工具     

超声消融结合动脉置管溶栓治疗糖尿病足58例的护理

糖尿病足是中老年糖尿病患者常见的并发症.主要原因是股浅动脉,腘动脉闭塞,腘动脉以下中小动脉闭塞,远端流出道不佳,足趾缺血性坏死.传统的内科保守治疗和介入治疗及外科手术效果都不理想.     

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.     

格林—巴利综合征患者血清和脑脊液中的抗硫脂抗体

探讨抗硫脂抗体与格林－巴利综合征（ＧＢＳ）的关系。方法采用固相酶联免疫吸附法对急性期ＧＢＳ患者血清和脑脊液（ＣＳＦ）中抗硫脂ＩｇＧ和ＩｇＭ抗体进行检测。结果ＧＢＳ患者血清和ＣＳＦ中抗硫脂ＩｇＧ及ＩｇＭ抗体的阳性率均明显高于正常对照组；血清中抗硫脂ＩｇＭ抗体滴度与标本收集时患者发病天数呈负相关（Ｐ＜０．０５），而血清中抗硫脂ＩｇＧ抗体滴度与临床分级（Ｐ＜０．０１）、ＣＳＦ中抗硫脂ＩｇＧ抗体滴度（Ｐ＜０．０１）呈正相关；血清中抗硫脂ＩｇＧ或ＩｇＭ阳性的ＧＢＳ患者，体检时有不同程度的感觉障碍患者为５６％，而血清中抗硫脂抗体阴性患者仅为１６％，两者之间差异有显著意义（Ｐ＜０．０５）。结论抗硫脂抗体可能在ＧＢＳ的病理过程中起重要作用     

深静脉置管预防阿昔洛韦致静脉炎的效果观察

目的探讨深静脉置管术预防阿昔洛韦致静脉炎的效果。方法随机将60例病毒性脑炎患者分为观察组和对照组各30例。观察组行深静脉置管,对照组采用头皮静脉针行静脉输入阿昔洛韦。结果观察组静脉炎发生率(16.7%)显著低于对照组(93.3%),差异有显著性意义(P<0.01)。结论深静脉置管可明显减少阿昔洛韦所致静脉的损害程度,降低静脉炎的发生率。     

Sample size determination for an exponential survival model with an unrestricted covariate

We derive formulae for estimating sample size and power for detecting the effect of an unrestricted covariate on survival time. These are useful in designing survival studies with different patterns of recruitment and follow-up when survival time is exponentially distributed. We use the asymptotic covariance matrix, conditional expectation and Taylor's expansion techniques to develop these formulae. Computer simulations indicate that the asymptotic approximations used in developing the formulae are good over a range of parameter values and different patterns of recruitment and follow-up that are relevant to survival studies.