Cristria plicata肝脏、肌肉组织提取物的生化性质与抗肿瘤活性比较

选取一种水生贝类软体动物Cristria plicata,分别提取其肝脏、肌肉组织中的亲水成分,并对其进行了比较研究。结果表明,两种组织提取物中5kD以下的成分经HPLC分析基本相似,均无抗肿瘤活性,主要抗肿瘤成分是一些相对分子质量大于30kD的蛋白质;蛋白质、糖含量及SDS－PAGE分析结果均表明二者主要抗肿瘤成分的性质基本相似;Cristria plicata肝脏提取物与肌肉组织提取物的最大区别是前者在Sephadex G-25柱层析中比后者多一个相对分子质量约5－15kD的抗肿瘤活性级分。这些研究结果表明Cristria plicata抗肿瘤物质不仅存在于肝,也存在于于肌肉组织中,由于肌肉组织来源丰富,从而为开发利用这种抗肿瘤药物资源提供了可能性。     

Isolation and identification of a new antibacterial entity from the Antarctic cyanobacterium Nostoc CCC 537

The present study was aimed at the isolation, purification and structural elucidation of an antibacterial entity/lead molecule from the Antarctic cyanobacterium Nostoc CCC 537. A methanolic extract of the cyanobacterium was bioassayed with Enterobacter aerogenes as a target. The extract was purified by TLC, and the most active band was subjected to HPLC. The fraction (retention time 15.7 min) designated as the active principle was antibacterial towards Gram positive Mycobacterium tuberculosis H37Rv, Staphylococcus aureus ATCC 25923, Gram negative Salmonella typhi MTCC 3216, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25992, Enterobacter aerogenes MTCC 2822 and multi-drug resistant strains of Escherichia coli GS 2003/01, 02, 03. Based on UV, IR, ¹H NMR, EIMS, and ESIMS data, the structure of the active principle is proposed as 4-[(5-carboxy-2-hydroxy)-benzyl]-1,10-dihydroxy-3,4,7,11,11-pentamethyloctahydrocyclopenta<a>naphthalene (Mr 428, Mp 243–249°C). This intracellular biomolecule is similar to anthraquinone and indane derivatives of a diterpenoid. The rate of production of the active principle currently corresponds to 1.70 mg g⁻¹ biomass dry weight. The inherent property of Nostoc sp. to synthesise niche-specific biomolecules/lead molecules may be exploited for future drug development.     

多通道神经元锋电位检测和分类的新方法

大脑神经元胞外单细胞动作电位(即锋电位)的检测和分类是提取神经元脉冲序列、研究神经系统信息处理机制的关键．为了提高锋电位的检出率和分类的正确性,设计了一种处理多通道锋电位记录信号的算法,用于分析微电极阵列记录的大鼠海马神经元锋电位信号,电极阵列上的测量点排列紧密,4个通道可以同时记录到来自相同神经元的信号．该算法首先利用一种多通道阈值检测法检出四通道记录信号中的锋电位,然后利用一种基于复合锋电位的主成分特征参数分类法将锋电位分类．仿真数据和实验记录信号的检验结果表明：与相应的单通道算法相比,该算法的锋电位检出率和分类的正确性显著提高,并且可以增加单次实验测得的神经元数目．因此,该算法为实现神经元锋电位的自动检测提供了一种简单有效的新 方法．     

蝎毒耐热蛋白对MPTP诱导的帕金森病小鼠脑内小胶质细胞的影响

目的：进一步探讨蝎毒耐热蛋白（SVHRP）改善MPTP（1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,MPTP）小鼠伴有空间学习记忆障碍的机制。方法：给予C57BL／6小鼠颈部皮下注射MPTP（20mg／kg）,连续8d,同时设立SVHRP治疗纽,观察小胶质细胞免疫反应活性的改变。结果：与盐水对照组相比,MPTP小鼠脑区OX-42免疫反应阳性小胶质细胞免疫反应活性明显增强。模型给药组与模型组相比OX-42免疫反应阳性小胶质细胞免疫反应活性明显降低。结论：SVHRP可以抑制MPTP诱发的小鼠脑内小胶质细胞的激活以减轻脑内神经炎症。     

人参总皂苷在神经干细胞移植治疗帕金森模型小鼠中的体内作用

目的：观察预先给小鼠体内注射人参总皂苷（TSPG）后,对帕金森病（PD）模型的建立以及神经干细胞（NSCs）移植的影响。方法：实验分5组。1～4组常规采用1-甲基4苯基-1,2,3,6-四羟吡啶（MPTP）建立PD小鼠模型;第5组建模前体内注射TSPG,干预PD模型的建立。建模前后用行为学指标以及震颤麻痹评分标准对模型进行评判。然后取第9周人胚胎大脑皮层NSCs,经TSPG预处理后植入上述5组PD小鼠纹状体内。移植60d后脑切片,做酪氨酸羟化酶（TH）免疫组化染色检测NSCs的分化状况。结果：体内预先注射TSPG能有效降低由MVFP引起的神经细胞损伤;在神经干细胞移植后,与其余4组相比,其震颤麻痹、自发活动、记忆功能的改善更为明显,脑切片中的多巴胺（DA）能神经元数量以及与相邻神经元建立的联系更为丰富。结论：TSPG的体内用药,可以更好的降低神经系统损害。并在NSCs移植治疗PD中发挥更好的作用。     

溶酶体抑制剂对小鼠行为学与黑质多巴胺神经元的影响

目的初步探讨溶酶体抑制剂对小鼠行为学及多巴胺神经元功能的影响。方法于小鼠右侧中脑黑质（SN）区,立体定向微量注入溶酶体抑制剂和蛋白酶体抑制剂。观察阿朴吗啡诱导的小鼠旋转行为改变以及行为学变化;检测黑质区酪氨酸羟化酶（TH）阳性细胞数。结果阿朴吗啡未能诱导出小鼠旋转行为。蛋白酶体抑制剂组为10～15圈。多巴胺损害程度与溶酶体的剂量相关。磷酸氯喹25μmol/L时多巴胺神经元几乎没有损害作用;50μmol/L时局部区域多巴胺神经元有轻微损害;100μmol/L时损害明显;200μmol/L时黑质区注射局部神经元损害最严重,黑质注射区未见有神经元存在。1～4周呈现出较为明显逐渐恢复的特点。结论溶酶体功能抑制与多巴胺神经元凋亡相关,不同剂量溶酶体抑制剂在不同时间对多巴胺神经功能的损害不同。     

Structuring process and closure principle in spatial and temporal reproduction tasks

The goal of the experiment reported was to replicate the previous Sarrazin’s (2000) study in order to verify, with an adequate methodological procedure, whether or not the closure principle applied in spatial and temporal reproduction tasks. The hypothesis defended was that the closure of the pattern is an intrinsic property of the structuring process in spatial memory. The stimuli consisted of eight visually presented dots that appeared sequentially with inter-dot distances corresponding to inter-dot durations. After a learning phase, participants reproduced the spatial (space condition) or temporal (time condition) characteristics of the target 60 times in succession. We analyzed the variance level for both element location and Inter-Element-Interval (IEI) on spatial and temporal responses. Two main results emerge from this experiment: (1) the critical dependency of the closure principle to the nature (spatial or temporal) of the response, (2) the importance to consider both locations and intervals as complementary information. These results are discussed in the light of physical system, in particular in term of compensation phenomenon and we proposed a mathematical model that replicates the qualitative feature of variance for both space and time conditions.     

Reprint of “Stereology meets electron tomography: towards quantitative 3D electron microscopy” [J. Struct. Biol. 159 (2007) 443–450]

Stereological tools are the gold standard for accurate (i.e., unbiased) and precise quantification of any microscopic sample. The past decades have provided a broad spectrum of tools to estimate a variety of parameters such as volumes, surfaces, lengths, and numbers. Some of them require pairs of parallel sections that can be produced by either physical or optical sectioning, with optical sectioning being much more efficient when applicable. Unfortunately, transmission electron microscopy could not fully profit from these riches, mainly because of the large depth of field. Hence, optical sectioning was a long-time desire for electron microscopists.This desire was fulfilled with the development of electron tomography that yield stacks of slices from electron microscopic sections. Now, parallel optical slices of a previously unimagined small thickness (2–5 nm axial resolution) can be produced. These optical slices minimize problems related to overprojection effects, and allow for direct stereological analysis, e.g., volume estimation with the Cavalieri principle and number estimation with the optical disector method.Here, we demonstrate that the symbiosis of stereology and electron tomography is an easy and efficient way for quantitative analysis at the electron microscopic level. We call this approach quantitative 3D electron microscopy.     

动物室氨浓度两种检测方法的对比

目的寻找方便、快捷、准确的实验动物环境中氨浓度检测方法。方法通过对《实验动物环境及设施》（GB14925-2001）中规定的纳氏试剂比色法和近年国内引进的Ammonia meter法两种检测室内的氨气浓度的方法比较研究。结果纳氏试剂比色法和Ammonia meter法检测结果存在差异显著性。结论在现阶段Ammonia meter法代替传统的纳氏试剂比色法的条件尚不成熟。同时,对实验采用方法进行说明。建议现行标准的吸收液浓度由0.5 mol/L修改为0.05 mol/L,吸收波长由500 nm修改为420 nm。     

LRRK2基因与帕金森病

帕金森病是一种复杂的多因素共同作用的神经变性性疾病,遗传因素和环境因素被认为是发病的重要原因。越来越多的研究发现遗传因素在其发病中起着重要作用,而最近LRRK2基因的发现更加确定了遗传因素在帕金森发病中不可忽视的作用。本文对LRRK2基因以及LRRK2基因在帕金森病中的研究做一综述。