兔耳纯静脉皮瓣血流量和血管网面密度观测

目的:观测纯静脉皮瓣术后血流量和血管网面密度变化。方法:利用家兔耳背设计纯静脉皮瓣和动脉皮瓣模型①观测术后血流量;②墨汁灌注后软蜡厚蜡切片,图像分析血管网面密度。结果:①纯静脉皮瓣术后48h血流量最低,第14d恢复至术前65%。②纯静脉皮瓣术后第1～7d的血管网面密度高于动脉皮瓣(P<0.05)。结论:纯静脉皮瓣术后血流量及血管网密度变化与动脉皮瓣不同。     

Auditory evoked potentials to tones and syllables in adults: evidence of specific influence on N250 wave

Brain-derived neurotrophic factor (BDNF) is involved in the differentiation and the survival of neurons. It has also been shown to be associated with the regrowth of neurons of damaged spinal cord and the modulation of ionic currents by acting on sodium channels and NMDA receptors through tyrosine kinase B (TrkB) receptors. We investigated the effects of BDNF on rhythm generation induced by disinhibition in dissociated cultures from embryonic rat spinal cord (E14), with extracellular multisite recordings (MultiElectrode Arrays, MEAs) or intracellular patch-clamp recordings. Exogenous BDNF had only minor effects on the bursting by increasing the activity during the burst. This increase of activity is suggested to be mediated by a potentiation of the postsynaptic NMDA receptors because it has been found that BDNF potentiates the NMDA-evoked depolarization in cultures incubated with BDNF for 10 min. Possible direct effects of BDNF on sodium channels were also investigated by local application of BDNF to the soma of patched neurons but no depolarization was observed. Long-term application of BDNF strongly decreased the activity during the burst and also the number of active electrodes, possibly due to a decrease in network density.     

An assessment of PKI and networked electronic patient record system: lessons learned from real patient data exchange at the platform of OCHIS (Osaka Community Healthcare Information System)

To enhance medical cooperation between the hospitals and clinics around Osaka local area, the healthcare network system, named Osaka Community Healthcare Information System (OCHIS), was established with support of a supplementary budget from the Japanese government in fiscal year 2002. Although the system has been based on healthcare public key infrastructure (PKI), there remain security issues to be solved technically and operationally. An experimental study was conducted to elucidate the central and the local function in terms of a registration authority and a time stamp authority in contract with the Japanese Medical Information Systems Organization (MEDIS) in 2003. This paper describes the experimental design and the results of the study concerning message security.     

Chronic ethanol exposure differentially regulates NOS1 mRNA levels depending on rat brain area

In vitro experiments were performed on brainstem – spinal cord preparations from mouse neonates to compare the noradrenergic regulations of the respiratory network in the control C3H/HeJ strain and the transgenic Tg8 strain which has been created from the C3H/HeJ strain by deletion of the gene encoding monoamine oxidase A (MAOA), the main enzyme for serotonin degradation. In both control and MAOA-deficient strains, we show: (i) that the pontine A5 area exerts a potent inhibitory modulation on the respiratory rhythm generator; (ii) that noradrenaline application induces a tonic phrenic activity; and (iii) that noradrenaline increases the respiratory rhythm. The latter effect is however delayed and weak in the Tg8 strain. Therefore, MAOA-deficiency has only slightly altered the noradrenergic regulations of the respiratory network.     

BicD-dependent localization processes: from Drosophilia development to human cell biology

Many eukaryotic cells depend on proper cell polarization for their development and physiological function. The establishment of these polarities often involve the subcellular localization of a specific subset of proteins, RNAs and organelles. In Drosophila, the microtubule-dependent BicD (BicaudalD) localization machinery is involved in the proper localization of mRNA during oogenesis and embryogenesis and the proper positioning of the oocyte and photoreceptor nuclei. BicD acts together with the minus-end directed motor dynein as well as Egl and Lis-1. The finding that the mammalian homologs of BicD function in retrograde Golgi-to-ER transport has supported the view that BicD may be part of a repeatedly used and evolutionary conserved localization machinery. In this review we focus on the various processes in which BicD is involved during Drosophilian development and in mammals. In addition, we evaluate the interactions between BicD, the dynein localization machinery and associated factors.     

在人工神经网络中引入混沌的必要性

本文从Freeman的生理学实验和仿真实验的结果出发,综合了Freeman和Tsuda对生物神经网络中混沌动力学的解释,从信息流动的角度论述了在生物神经网络中混沌存在的必要性和引入混沌机制的人工神经网络模型所具有的信息处理的潜力,指出认知系统对外界输入的反应是其动力学行为性质的改变而不仅是静态的数值输出.并认为具有混沌动力学性质的神经网络应同时具有模式分类器和解释器的双重作用.这一结合来自于系统的混沌动力性质.描述了混沌在模式识别中的作用,指出了其相对ART等传统神经网络模型的一些优势.部分结论在仿真实验中得到了证实.     

Holter系统的技术要求及神经网络方法

为了长时间、准确的记录分分析体表ＥＣＧ，从各个方面满足基础研究、临床、康复以及特殊生理需要，对Ｈｏｌｔｅｒ系统提出了愈来愈高的要求。作者从技术实现的角度讨论了Ｈｏｌｔｅｒ的主要技术要求，包括记录部分和分析部分；还介绍了几种用神经网络模型满足Ｈｏｌｔｅｒ系统技术要求的原理，包括用多层感知器实现数据压缩及分类，用高阶神经网络实现ＥＣＧ的分类，以及用ＡＲＴ模型识别ＥＣＧ中的Ｐ波与Ｔ波。     

用高价人抗HBs在人体内诱导产生抗HBs

本文探讨用外源性人抗HBs在人体通过免疫网络诱导产生自身的抗HBs的可能性。志愿者经多次注射人高价抗HBs(Ab_1)后,体内产生了Ab_2,进而产生出特异性与Ab_1相同的Ab_3;当Ab_3水平升高时,Ab_2水平下降。此结果证实了人体内独特型网络的存在及其活跃的调节功能,表明用于被动免疫的人抗HBs在人体也能通过激活独特型网络产生主动免疫保护作用。此外,本文的结果还提示,注射人抗HBs后,人体内产生的Ab_2可模拟HBsAg,使常规的HBsAg检查出现假阳性结果。     

大学生个体印象管理对其社会网络质量的影响

目的:研究个体印象管理对其社会网络质量的影响。方法:选用社会网络调查法、大学生印象管理量表,对46名大学生进行调查。结果:印象管理建构的提高不利于朋友网和沟通网的强联系人数量的增加(β分别为-1.04和-1.33,P分别小于0.05和0.01;F值分别为4.19和6.45,P分别小于0.05和0.01),而印象管理动机对强联系人的数量并没有影响,并且印象管理动机和印象管理结构都不影响个体为中心网络的紧密性。结论:只有个体印象管理的建构部分不利于其社会网络中的强联系人数量的增加。其他部分对社会网络无明显影响。     

Neural dynamics in cortex-striatum co-cultures-II. Spatiotemporal characteristics of neuronal activity

Neural dynamics in organotypic cortex-striatum co-cultures grown for three to six weeks under conditions of dopamine deficiency are described. Single neuron activities were recorded intra- and extracellularly, and spatiotemporal spreading of population activity was mapped using voltage-sensitive dyes. The temporal properties of spike firing were characterized by interspike interval histograms, autocorrelation and crosscorrelation.

Cortical pyramidal neurons (n = 40) showed irregular firing with a weak tendency to burst or to oscillate. Crosscorrelations revealed strong near-coincident firing and synaptic interactions. Disinhibition was a notable feature in a strongly firing cortical interneuron. Cortical activity spread in the co-culture, thus inducing an overall, homogeneous depolarization in the striatal part. Striatal cells were divided into principal cells and type I and II secondary cells. Principal cells (n = 40) were similar to those reported previously in vivo. Spiking activity ranged from irregular spiking at very low rates to episodic bursting, with an average burst duration of 1 s. Interspike intervals were single-peaked. Intracellular recordings revealed characteristic, long-lasting subthreshold depolarizations (“enabled state”) that were shortened by local muscarinic receptor blockade. During prolonged time periods in the “enabled state”, locally applied bicuculline induced strong firing in most principal neurons. Striatal secondary type I neurons (n = 25) showed high spiking rates, single- and double-peaked interval histograms and low-threshold, short-lasting stereotyped bursting activity and occasional rhythmic bursting. The firing of these neurons was increased by bicuculline. Crosscorrelations showed synchronization of these cells with principal cell activity. Secondary type II neurons (n = 15) revealed tonic, irregular firing patterns similar to cortical neurons, except with occasional firing in doublet spikes.

We conclude that under conditions of dopamine deficiency in corticostriatal co-cultures (i) the cortex induces the “enabled” state and typical bursting mode in striatal principal neurons; (ii) principal neurons are strongly inhibited during the “enabled” state; (iii) muscarinic activity, presumably from tonically active striatal cholinergic interneurons, stabilizes the “enabled” state; (iv) striatal GABAergic interneurons receive synaptic inhibition and take part in synchronized activity among striatal principal cells. Our results favor the view of the striatum as a lateral inhibition network.