Dual Electrophysiological Recordings of Synaptically-evoked Astroglial and Neuronal Responses in Acute Hippocampal Slices

Astrocytes form together with neurons tripartite synapses, where they integrate and modulate neuronal activity. Indeed, astrocytes sense neuronal inputs through activation of their ion channels and neurotransmitter receptors, and process information in part through activity-dependent release of gliotransmitters. Furthermore, astrocytes constitute the main uptake system for glutamate, contribute to potassium spatial buffering, as well as to GABA clearance. These cells therefore constantly monitor synaptic activity, and are thereby sensitive indicators for alterations in synaptically-released glutamate, GABA and extracellular potassium levels. Additionally, alterations in astroglial uptake activity or buffering capacity can have severe effects on neuronal functions, and might be overlooked when characterizing physiopathological situations or knockout mice. Dual recording of neuronal and astroglial activities is therefore an important method to study alterations in synaptic strength associated to concomitant changes in astroglial uptake and buffering capacities. Here we describe how to prepare hippocampal slices, how to identify stratum radiatum astrocytes, and how to record simultaneously neuronal and astroglial electrophysiological responses. Furthermore, we describe how to isolate pharmacologically the synaptically-evoked astroglial currents.     

Improved enrichment and proteomic identification of outer membrane proteins from a Gram-negative bacterium: focus on Caulobacter crescentus

Efforts to characterize proteins found in the outer membrane (OM) of Gram-negative bacteria have been steadily increasing due to the promise of expanding our understanding of fundamental bacterial processes such as cell adhesion or cell wall biogenesis as well as the promise of finding potential vaccine- or drug-targets for virulent bacteria. We have developed a mass spectrometry-compatible experimental strategy that resulted in increased coverage of the OM proteome of a model organism, Caulobacter crescentus. The specificity of the OM enrichment step was improved by using detergent solubilization of the protein pellet, low-density cell culture conditions, and a surface-layer deficient cell line. Additionally, efficient gel-assisted digestion, high-resolution RP/RP-MS/MS, and rigorous bioinformatic analysis led to the identification of 234 proteins using strict identification criteria (≥ two unique peptides per protein; peptide false discovery rate <2%). Eighty-four of the detected proteins were predicted to localize to the OM or extracellular space. These results represent ~70% coverage of the predicted OM/extracellular proteome of C. crescentus. This analytical approach, which considers important experimental variables not previously explored in published OM protein studies, can be applied to other OM proteomic endeavors "as is" or with slight modification and should improve the large-scale study of this especially challenging subproteome.     

秸秆降解菌剂对秸秆还田土壤中细菌种群数量的影响

要研究秸秆降解菌剂施用后1个生长季秸秆中细菌的数量和纤维素酶活力,了解其动态变化,为进一步研究分析土壤中微生物结构变化规律提供可靠的理论依据.利用分子生物学方法,对秸秆降解菌剂施用后不同生长阶段耕层中细菌基因组DNA纯化后PCR扩增其16S rDNA V3可变区,对扩增产物进行DGGE电泳,并对结果进行分析.初步分析表明,菌落数量呈现前期上升、中期最高、后期逐渐降低的趋势.     

做好实验准备工作,提高微生物学实验教学质量

完善的微生物学实验准备工作是确保实验成功的开始,也是提高微生物学实验教学质量的重要环节。从加强实验室管理,制定详细的实验准备内容,严格进行实验预做等方面介绍做好微生物学实验准备工作的经验,为提高实验教学质量,培养具有创新能力的人才提供参考和借鉴。     

S/D法灭活血液制剂中脂包膜病毒效果验证的研究

选用不同核酸的脂包膜病毒,其中RNA病毒为水疱性口炎病毒(VSV),DNA病毒为伪狂犬病毒(PRV),将两种指示病毒分别用于验证S/D法处理对纤维蛋白原、凝血酶原复合物、凝血因子Ⅷ、静注丙种球蛋白、免疫血浆等血液制剂的病毒灭活效果。结果该法对所有被处理的血液制剂中的PRV及VSV灭活能力分别为≥3.38~5.88和≥3.50~4.75logTCID50/0.1ml,表明S/D法对两种病毒核酸类型的脂包膜病毒有良好的灭活效果。     

乳化溶剂挥发法制备纳米粒

目的：建立乳化溶剂挥发法制备纳米粒的方法。方法：采用单因素法和正交设计法考察不同影响因素对乳化溶剂挥发法所制得的纳米粒粒径、包封率和载药量的影响。结果：采用乳化溶剂挥发法,通过改变处方和工艺因素所制得的纳米粒,外观圆整,大小均匀,粒径可控,包封率多数可达50%以上。结论：优化确立了乳化溶剂挥发法制备纳米粒的处方和工艺,可以制备满足不同要求的纳米粒。     

蛋白质组学研究相关技术及进展

蛋白质组学以蛋白质组为研究对象,应用相关研究技术,从整体水平上来认识蛋白的存在及活动方式。随着人类基因组计划的完成,蛋白质组学的研究也得到了快速发展,与蛋白质组学研究相关的一些技术也日益得到完善和提高。简要综述了近年来蛋白质组学研究中最为重要的样品制备、蛋白质分离、蛋白质鉴定等技术及研究进展。     

微生物学实验网上预习与管理系统及其在实验教学中的应用

实验预习是实验教学的首要环节,是学生在开放实验室高效实验的基本保证.针对我校微生物学实验的教学特点和要求,开发设计了微生物学实验网上预习与管理系统并应用于微生物实验教学中.该系统集学生预习和教师管理于一体,每个实验都包括有实验目的,实验原理、实验材料与仪器设备、实验演示、模拟实验和预习测试等6个环节.教学实践证明,该系统的应用从根本上确保了学生实验预习的质量,使实验教学管理更加规范、标准和高效,有效地保证了微生物实验教学质量.     

Collection fluid helps preservation in voided urine cytology

Objectives:  Degenerative change caused by delay in processing contributes to false-negative and false-positive diagnosis of urothelial carcinoma in cytology. The aim of the study was to see if the use of a collection fluid for urine samples made a significant difference to urine cytology diagnosis, and if one was better suited for routine use in the hospital laboratory. Three cell collection fluids were evaluated by analysing the preservation and degeneration of cells in urine samples, as was the routine preparation which did not use a collection fluid.
Methods:  In the design study 50 voided urine specimens were taken at random from the hospital haematuria clinic. Three commercially available collection fluids cytolyt^TM, cytospin^® and cytoRich^®Blue and the hospital's routine conventional preparation of urine were compared. The degree of degeneration, and so preservation, was assessed by a table of chosen criteria; then ranked and analysed by Friedman's nonparametric test, at P  = 0.05. A second table showing the cell content of each slide was also made.
Results:  These showed no significant diagnostic difference between the collection fluids, but there was a significant difference between the collection fluids and the routine preparation. Minor differences that do not affect diagnosis, such as crystals and ghost red blood cells, were noted in cytospin^® and cytoRich^®Blue.
Conclusion:  It is recommended that a collection fluid is used. This choice should be made after health and safety issues and cost are considered.     

感受态细胞制备与保存方法的比较研究

目的 :确立一个能制备高转化率感受态细胞并长期维持其感受性的实验方案。方法 :比较CaCl2 法、TSS法、超高效法制备感受态细胞的效果 ,选用三者中较好的方法进一步探讨不同生长期 (OD值 0 .2～ 1.1)的细菌对制备感受态细胞的影响 ,并分别比较了不同冷冻保护剂 (7%DMSO ,10 %甘油 )于 - 2 0℃、- 80℃冰箱保存感受态细胞的效果。结果 :三种方法获得的感受态细胞转化率差异极显著 (P <0 .0 1)。采用超高效法 ,OD值为 0 .36 (或 0 .5 8)时收集菌体可获得 1.1× 10 8的高转化率的感受态细胞 ,以 7%的DMSO为冷冻保护剂保存感受态细胞可维持 10 7以上的转化率 4 0d以上