Repetitive Transcranial Magnetic Stimulation Ameliorates Anxiety-Like Behavior and Impaired Sensorimotor Gating in a Rat Model of Post-Traumatic Stress Disorder

BackgroundRepetitive transcranial magnetic stimulation (rTMS) has been employed for decades as a non-pharmacologic treatment for post-traumatic stress disorder (PTSD). Although a link has been suggested between PTSD and impaired sensorimotor gating (SG), studies assessing the effects of rTMS against PTSD or PTSD with impaired SG are scarce.AimTo assess the benefit of rTMS in a rat model of PTSD.MethodsUsing a modified single prolonged stress (SPS&S) rat model of PTSD, behavioral parameters were acquired using open field test (OFT), elevated plus maze test (EPMT), and prepulse inhibition trial (PPI), with or without 7 days of high frequency (10Hz) rTMS treatment of SPS&S rats.ResultsAnxiety-like behavior, impaired SG and increased plasma level of cortisol were observed in SPS&S animals after stress for a prolonged time. Interestingly, rTMS administered immediately after stress prevented those impairment.ConclusionStress-induced anxiety-like behavior, increased plasma level of cortisol and impaired PPI occur after stress and high-frequency rTMS has the potential to ameliorate this behavior, suggesting that high frequency rTMS should be further evaluated for its use as a method for preventing PTSD.     

FRIL蛋白体外维持脐血造血干/祖细胞的作用及细胞周期调控基因的表达

为探讨新的豆类凝集素(Flt3 receptor-interacting lectin,FRIL)体外维持脐血CD34^ 细胞的作用以及维持过程中细胞周期调控基因HTm4及HTm4S mRNA的表达及意义,我们利用FRIL维持培养脐血CD34^ 细胞,对其增殖曲线、细胞周期及集落形成能力进行常规分析,并用半定量RT—PCR法分别测定FRIL体外维持不同时间后脐血CD34^ 细胞中周期调控基因HTm4及HTm4S mRNA的表达变化。结果显示,FRIL培养的CD34^ 造血干／祖细胞的增殖趋势平缓,整个培养期间细胞增殖倍数不超过起始的3倍：14d之前,FRIL培养细胞的高增殖潜能集落形成细胞(HPP—CFC)形成集落数与FL组无差别,其后则维持高于FL的情况。细胞周期分析则显示,在28d的培养过程内,利用FRIL培养的细胞始终有80％以上维持在G0期;而周期调控基因HTm4及HTm4S在刚分离的脐血CD34^ 细胞中的表达水平较高;但培养1d后,几乎检测不到HTm4基因的表达;培养3～14d,该基因的表达回升并持续维持在高水平。而HTm4S基因的表达在第7d达最高水平,其余时间基本呈稳定表达。转染HTm4和HTm4S,亚细胞定位结果显示HTm4主要定位于核周围,而HTm4S则定位于整个胞浆,由此可能导致它们功能的区别。以上结果提示,长期培养体现出FRIL在维持造血干／祖细胞多能性上的优势;细胞周期调控基因HTm4及其新剪接子参与了FRIL体外长期维持脐血造血干／祖细胞处于静息状态的过程。     

克鲁斯假丝酵母及其近似种的脉冲电泳核型分析

用钳位均匀电场脉冲电泳(CHEF)系统分析了克鲁斯假丝酵母(Candida krusei),郎比可假丝酵母(C. lambica)和粗状假丝酵母(C. valiad)的模式菌株的电泳核型,发现这三种表型相似的假丝酵母却具有互不相同的染色体DNA分子带型,为其分类学研究提供了可靠的鉴别依据。在常规分类学研究的基础上,测定了AS 2.75(原定种名为(C. incospicua),AS2.1182(原定种名为 C. lambica)和AS 2.1772(未定种)等三株假丝酵母的G+C含量和脉冲电泳核型。通过对已报道的C. inconspicu的G+C含量及上述三种假丝酵母模式菌株的脉冲电泳核型的比较分析证明,AS 2.75和AS 2.1772为粗状假丝酵母(C. valida),AS 2.1182为克鲁斯假丝酵母(C. krusei)。     

Synthesis and antioxidant evaluation of novel silybin analogues

In this work, we evaluated the antioxidant properties of the eight novel silybin analogues for their capacity to scavenge free radicals including superoxide anion radicals and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals in vitro. Compound 7d demonstrated an excellent antioxidant effect in scavenging superoxide anion free radical with an IC50 value of 26.5 microM, while the IC50 of quercetin (the reference compound) was 38.1 microM. Compounds 7b, 7e, 7h showed certain scavenging activities for both types of free radicals.     

Application of impedance spectroscopy for monitoring colloid Au-enhanced antibody immobilization and antibody-antigen reactions

We used colloidal Au to enhance the amount of antibody immobilized on a gold electrode and ultimately monitored the interaction of antigen-antibody by impedance measurement. Self-assembly of 6 nm (diameter) colloidal Au onto the self-assembled monolayers (SAMs) of 4-aminothiophenol modified gold electrode resulted in an easier attachment of antibody. The redox reactions of [Fe(CN)6](4-)/[Fe(CN)6](3-) on the gold surface were blocked due to the procedures of self-assembly of 4-aminothiophenol and antibody immobilization, which were investigated by cyclic voltammetry and impedance spectroscopy. The interaction of antigen with grafted antibody recognition layers was carried out by soaking the modified electrode into a phosphate buffer at pH 7.4 with various concentrations of antigen at 37 degrees C for 30 min. The antibody recognition layers and their interactions with various concentrations of antigen could be detected by measurements of the impedance change. The results show that this method has good correlation for detection of Hepatitis B virus surface antigen in the range of 0.5-200 microg/l and a detection limit of about 50 ng/l.     

The Regulation and Function of Histone Methylation

Histones are wrapped around by genomic DNA to form nucleosomes which are the basic units of chromatin. In eukaryotes histones undergo various covalent modifications such as methylation, phosphorylation, acetylation, ubiquitination and ribosylation. Histone modifications play a fundamental role in the epigenetic regulation of gene expression in multicellular eukaryotes. Histone methylation is one of the most important modifications occurring on Lysine (K) and Arginine (R) residues of histones, dynamically regulated by histone methyltransferases and demethylases. Identifications of such histone modification enzymes and to study how they work are the most fundamental questions needs to be answered. Uncovering the regulation and functions of the various histone methylation enzymes will help us to better understand the epigenetic code. This review summarizes the regulation of histone methyltransferases activity, the recruitment of methyltransferases and the distribution patterns and function of histone methylations.     

老芒麦遗传多样性及育种研究进展

老芒麦（Elymus sibiricus）的研究对我国北方草原及青藏高原高寒草甸的退化草地改良、发展草地畜牧业具有重要意义。本文综述了老芒麦在形态学、细胞学、蛋白质和DNA分子水平上的遗传多样性研究概况,并总结了国内老芒麦的育种研究进展。目前国内外专门针对不同老芒麦种质材料（accession）或居群（populations）遗传多样性的研究鲜见报道,相关研究主要集中在与披碱草属（Elymus）及其近缘小麦族物种的系统进化研究方面;其次,我国仅有6个老芒麦国家审定品种,且育种手段较单一、落后,育成品种优势集中在产量和适应性上,缺乏对抗逆性种质的筛选培育。     

微流控芯片技术在细胞生物学研究中的应用进展

20世纪90年代以来,微流控芯片技术得到了快速发展。由于具有小型化、集成化、高通量、低消耗、分析快速等特点,微流控芯片作为一种新型的生物学研究平台,能够提供传统方法不具备的精细和可控制的细胞研究条件,在细胞生物学研究领域中得到了广泛关注。该文主要介绍其在细胞培养、分选、裂解、计数、凋亡检测、迁移、单细胞捕获、细胞间作用等方面的研究进展。     

CO2倍增对不同基因型大豆光合色素含量和荧光诱导动力学参数的影响

研究了CO_2倍增对大豆(Glycine max L.)Bragg(野生型)及其不同单基因突变品系Nts 382(超结瘤突变体)和Nod 49(不结瘤突变体)某些光合特性的影响。结果表明,CO_2倍增能提高Bragg、Nts 382和Nod 49的叶绿素(Chl)和类胡萝卜素(Car)的含量,但不同品系提高的幅度有所不同。荧光诱导动力学测定结果表明,CO_2倍增均能提高其PSⅡ活性、PSⅡ原初光能转化效率和光合作用潜在量子转化效率。CO_2倍增更有利于提高Nts 382的荧光光化学猝灭系数(qp)和PSⅡ总的光化学量子产量,以及较大幅度地降低荧光非光化学猝灭系数(qN),有助于把所捕获的光能用于进行光合作用。这可能与Nts 382是超结瘤突变体,比Bragg和Nod 49能更充分地利用空气中的氮素有关。     

1982-2016年东北黑土区植被NDVI动态及其对气候变化的响应

植被是陆地生态系统的重要组成部分,在调节气候、水土保持等方面具有重要作用,因此,监测植被生长变化并探讨其与气候变化之间的关系,在全球变化研究中具有重要意义。基于MODIS NDVI和GIMMS NDVI数据集,并通过一致性检验,在区域和像元两个空间尺度上,利用一元线性回归模型,研究东北黑土区1982-2016年植被生长动态,分析植被生长对气温和降水量的响应程度。结果表明：区域尺度上,1982-2016年东北黑土区植被生长季NDVI变化分为3个阶段（先增加继而减少最后再增加）,区域植被的生长在气温、降水量的共同作用下,呈现出明显季节差异;像元尺度上,1982-2016年东北黑土区NDVI总体趋势为改善状态,主要改善植被类型为草原、森林和农业植被,鹤岗市、绥化市和长春市改善面积较大;多年平均NDVI值与同期气温和降水量具有一定的相关关系,平原地区植被NDVI与气温主要呈显著正相关关系,植被类型主要为耕地;平原地区边缘和山地地区的植被NDVI与降水量以显著正相关关系为主,主要植被类型为森林和草地。