战场环境封闭强化训练慢性应激致维和军人血清IL-6、TNF-α和执行功能的变化

目的探讨战场环境封闭训练慢性应激对维和军人血清白细胞介素IL-6(interleukin-6,IL-6)、肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)和执行功能的影响。方法随机选择参加南苏丹维和部队的军人41名,分别在出国前和平环境封闭训练5个月和在南苏丹战场环境中封闭训练5个月后,进行执行功能测验,包括数字符号测验、数字广度测验、词语流畅以及Stroop色词测验,并同期分别采用ELLISA进行血IL-6和TNF-α的检验。结果维和军人在战场环境下封闭训练5个月后数字符号测验得分(55.71±12.47)、数字广度测验得分(12.46±3.30)及词语流畅得分(48.49±8.07)均低于出国前和平环境中的得分(分别为62.29±10.88、14.88±2.96、49.88±8.32,均P0.01),Stroop 1〔(67.76±15.85)s〕、Stroop 2〔(28.15±5.32)s〕计时长于其出国前和平环境中的计时〔(55.73±15.50)s、(23.05±3.72)s,均P=0.00〕。维和军人战场环摬封闭强训练5个月后的IL-6〔(204.61±94.98)ng/L〕和TNF-α〔(53.18±2.69)pg/mL〕水平高于其出国前和平环境封闭训练时水平〔分别为(144.19±72.40)ng/L和(45.01±3.61)pg/mL,均P0.05〕,但IL-6、TNF-α均在正常范围内。结论战场环境条件下封闭训练慢性应激可能影响维和军人执行功能及血清IL-6、和TNF-α水平。     

大鼠初级躯体感觉皮层后肢代表区的神经回路和时间可塑性:平面微电极阵列记录技术的应用(英文)

目的运用平面微电极阵列记录技术探讨大鼠初级躯体感觉皮层(primary somatosensory cortex,S1 area)后肢代表区的神经回路和时间可塑性。方法将急性分离的大鼠脑片置于MED-64系统的电极平皿中,持续灌流通入95%O2和5%CO2混合气的人工脑脊液,随后进行多电极同时同步记录。利用双线性内插法计算出64个点的电流源与电流井,并将其转换为二维电流源密度分布图。结果刺激S1后肢代表区脑片的II-III层,可鉴定出局部皮层内的连接回路,而刺激IV层(丘脑传入的主要终末端)则鉴定出丘脑皮层间的连接回路。首先,丘脑皮层投射的激活可以诱发更多的有效场电位,并且与S1区更多的神经元建立突触联系。与之相比,皮层内回路的激活引起的电反应活动范围则较小。其次,刺激IV层在每一刺激强度下诱发的场电位幅度远远大于刺激II-III的场电位幅度,即S1区更容易被丘脑皮层连接回路的投射纤维所激活。最后,在S1区IV层给予强直刺激可以记录到长达两个小时的局部场电位幅度的增加,长时程增强(long-term potentiation,LTP)的诱出率约为83.3%(5/6例)。相反,在II-III层,同样的强直刺激并...     

血清尿酸与脑梗死复发的相关性分析

目的探讨血清尿酸水平与老年脑梗死患者复发的关系。方法以2006年1月1日至2008年12月30Et期间在山东省4家医院住院的老年急性脑梗死患者1033例为研究对象,采用回顾性分析方法,收集人口统计学、生活方式、疾病史、入院尿酸水平以及脑梗死病史。采用多因素分析方法分析尿酸水平与脑梗死复发的关系。结果复发脑梗死患者尿酸水平明显高于初发脑梗死患者,多因素调整后尿酸水平每升高1个单位,脑梗死患者复发的相对危险性比值比（OR）（95％可信区间CI）为1．002（1．000～1．003）,显示尿酸水平升高与脑梗死复发相关联。进一步按尿酸四分位数进行分析,与尿酸最低四分位（〈211lμmol／L）水平的脑梗死患者相比,尿酸水平在263～333μmol／L、≥333μmol／L的患者发生不良结局的OR值（95％CI）分别为1．951（1．340～2．839）、1．670（1．140～2．448）。而在211~263μmol／L水平,这种趋势无统计学意义。结论血清尿酸水平升高是脑梗死复发的独立危险因素。     

先天性静止性夜盲大鼠视杆双极细胞L-钙通道电生理特征

目的研究先天性静止性夜盲（CSNB）大鼠视杆双极细胞（RBCs）L-钙通道的生理学特征,探讨其与视觉信号传导通路障碍的关系。方法选取4～8周龄SD大鼠20只（对照组）、CSNB大鼠23只（实验组）,深度麻醉后处死大鼠,制作视网膜切片,红外显微镜下寻找RBCs胞体,运用全细胞膜片钳模式记录L-钙通道电流,并记录程序刺激后细胞静息膜电容（restCm）的变化值（△Cm）,计算胞吐系数（EI）。结果对照组L-钙通道电流于-20～-30mV达到峰值（-33.2±2.5）pA,实验组电流于-15mV左右达峰值,为（12.2±2.3）pA;L-钙通道特异性阻断剂nifedipine（10μm）可以完全阻断所记录的钙电流。GABA受体阻断剂PTX（100μm）能够明显阻断实验组除极时诱发的外向电流。与对照组比较,实验组的△Cm和EI均明显降低（P〈0.01）。结论 CSNB大鼠双极细胞L-钙通道电生理特征的改变会严重影响其向下级神经元释放神经递质,这可能是导致CSNB发病的机制之一。     

Neural circuits and temporal plasticity in hindlimb representation of rat primary somatosensory cortex: revisited by multi-electrode array on brain slices

Objective

The well-established planar multi-electrode array recording technique was used to investigate neural circuits and temporal plasticity in the hindlimb representation of the rat primary somatosensory cortex (S1 area).

Methods

Freshly dissociated acute brain slices of rats were subject to constant perfusion with oxygenated artificial cerebrospinal fluid (95% O₂ and 5% CO₂), and were mounted on a Med64 probe (64 electrodes, 8×8 array) for simultaneous multi-site electrophysiological recordings. Current sources and sinks across all the 64 electrodes were transformed into two-dimensional current source density images by bilinear interpolation at each point of the 64 electrodes.

Results

The local intracortical connection, which is involved in mediation of downward information flow across layers II–VI, was identified by electrical stimulation (ES) at layers II–III. The thalamocortical connection, which is mainly involved in mediation of upward information flow across layers II–IV, was also characterized by ES at layer IV. The thalamocortical afferent projections were likely to make more synaptic contacts with S1 neurons than the intracortical connections did. Moreover, the S1 area was shown to be more easily activated and more intensively innervated by the thalamocortical afferent projections than by the intracortical connections. Finally, bursting conditioning stimulus (CS) applied within layer IV of the S1 area could successfully induce long-term potentiation (LTP) in 5 of the 6 slices (83.3%), while the same CS application at layers II–III induced no LTP in any of the 6 tested slices.

Conclusion

The rat hindlimb representation of S1 area is likely to have at least 2 patterns of neural circuits on brain slices: one is the intracortical circuit (ICC) formed by interlaminar connections from layers II–III, and the other is the thalamocortical circuit (TCC) mediated by afferent connections from layer IV. Besides, ICC of the S1 area is spatially limited, with less plasticity, while TCC is spatially extensive and exhibits a better plasticity in response to somatosensory afferent stimulation. The present data provide a useful experimental model for further studying microcircuit properties in S1 cortex at the network level in vitro.     

临床医学院教学制度建设的探索与实践

临床医学院制度建设和树立"制度意识"是最基础又是最根本的建设。针对临床医学院教学工作中存在的问题,必须建立有效的教学制度,主要体现在以下三个方面:教学评价的重要性;教学成效的可预测性;教学问题的可防范性。为此,我们就建立了相应的教学流程及其制度,获得了一定的成效。