A genetically engineered <Emphasis Type="Italic">Escherichia coli</Emphasis>, expressing the fusion protein of green fluorescent protein and carboxylesterase B1, can be easily detected in the environment following degradation of pesticide residues

Genetically engineered Escherichia coli, expressing the fusion protein of enhanced green fluorescent protein (EGFP) and carboxylesterase B1 (CarE B1), was successfully constructed by cloning the genes into the pET-28b vector and then transforming E. coli BL21 (DE3). Expression of the fusion protein was induced in E. coli BL21 (DE3) which could then degrade environmental pesticides and could be easily detected using fluorescence spectrophotometry or by the naked eye in daylight.     

溶血卵磷脂对小鼠及鸡脑突触体内钙离子浓度的升高作用

鸡是有机磷引起的迟发性神经病(OPIDN)的最常用的动物模型,OPIDN的发生被认为与神经病靶酯酶(NTE)的抑制有关。本研究比较了NTE的生理性底物溶血卵磷脂(LPC)对鸡和小鼠脑突触体内钙离子浓度的影响。LPC能够浓度依赖性地引起小鼠和鸡脑突触体内游离钙浓度升高,且在两种动物来源的突触体上的反应趋势和幅度基本相同。去掉突触体悬液中Ca2 后,同样在LPC的作用下,突触体内钙浓度不但没有升高反而明显下降,这在两种来源的突触体上的结果相同。L型钙通道阻断剂维尔帕米和非特异性钙通道阻断剂氯化镉均对LPC引起的小鼠和鸡脑突触体内钙升高都没有阻断作用。这些结果表明,LPC主要通过其对膜的破坏作用引起小鼠和鸡脑突触体内的游离钙浓度升高,且在小鼠和鸡脑突触体内钙离子浓度升高的幅度和机制方面没有种属差异。本研究的结果表明:鸡和小鼠在OPIDN中的症状差异并非由于LPC介导突触体内钙超载的强度不同所导致。     

Down-regulation of MSH2 expression by an Hsp90 inhibitor enhances pemetrexed-induced cytotoxicity in human non-small-cell lung cancer cells

Elevated heat shock protein 90 (Hsp90) expression has been linked to poor prognosis in patients with non-small cell lung cancer (NSCLC). The multitargeted antifolate pemetrexed has demonstrated certain clinical activities against NSCLC. However, the efficacy of the combination of pemtrexed and Hsp90 inhibitor to prolong the survival of patients with NSCLC still remains unclear. Human MutS homolog 2 (MSH2), a crucial element of the highly conserved DNA mismatch repair system, and defects or polymorphisms of MSH2 have been found in lung cancer. In this study, we evaluated the effects of pemetrexed on NSCLC cell lines (H520 and H1703) and found that treatment with this drug at 20–50 µM increased the MSH2 mRNA and protein levels in a MKK3/6–p38 MAPK signal activation-dependent manner. Furthermore, the knockdown of MSH2 expression by transfection with small interfering RNA of MSH2 or the blockage of p38 MAPK activation by SB202190 enhanced the cytotoxicity of pemetrexed. Combining the drug treatment with an Hsp90 inhibitor resulted in an enhanced pemetrexed-induced cytotoxic effect, accompanied with the reduction of MSH2 protein and mRNA levels. The expression of constitutively active MKK6 (MKK6E) or HA-p38 MAPK vectors significantly rescued the decreased p38 MAPK activity, and restored the MSH2 protein levels and cell survival in NSCLC cells co-treated with pemetrexed and Hsp90 inhibitor. In this study, we have demonstrated that down-regulation of the MKK3/6–p38 MAPK signal with the subsequent reduction of MSH2 enhanced the cytotoxic effect of pemetrexed in H520 and H1703 cells. The results suggest a potential future benefit of combining pemetrexed and the Hsp90 inhibitor to treat lung cancer.     

Cortical thinning in patients with recent onset post-traumatic stress disorder after a single prolonged trauma exposure

Most of magnetic resonance imaging (MRI) studies about post-traumatic stress disorder (PTSD) focused primarily on measuring of small brain structure volume or regional brain volume changes. There were rare reports investigating cortical thickness alterations in recent onset PTSD. Recent advances in computational analysis made it possible to measure cortical thickness in a fully automatic way, along with voxel-based morphometry (VBM) that enables an exploration of global structural changes throughout the brain by applying statistical parametric mapping (SPM) to high-resolution MRI. In this paper, Laplacian method was utilized to estimate cortical thickness after automatic segmentation of gray matter from MR images under SPM. Then thickness maps were analyzed by SPM8. Comparison between 10 survivors from a mining disaster with recent onset PTSD and 10 survivors without PTSD from the same trauma indicates cortical thinning in the left parietal lobe, right inferior frontal gyrus, and right parahippocampal gyrus. The regional cortical thickness of the right inferior frontal gyrus showed a significant negative correlation with the CAPS score in the patients with PTSD. Our study suggests that shape-related cortical thickness analysis may be more sensitive than volumetric analysis to subtle alteration at early stage of PTSD.     

神经病靶标酯酶调控结构域结合蛋白筛选及其在COS-7细胞中的表达

本研究采用酵母双杂交系统探寻与神经病靶标酯酶（NTE）调控结构域相互作用的蛋白因子,揭示与NTE信号转导相关的可能机制。通过构建含有NTE调控结构域的诱饵蛋白载体筛选胎脑文库,并将筛选得到的阳性克隆在酵母中进行了验证,随后在哺乳动物细胞中表达了该蛋白。生物信息学分析显示：该阳性克隆为前列腺素受体结合蛋白54（ARA54）,具有泛素连接酶活性,提示细胞可能存在依赖于细胞周期的NTE活性调节机制,为阐明NTE生理功能创造了条件[动物学报51（5）：840—844,2005]。     

Phylogeography of a widespread terrestrial vertebrate in a barely-studied Palearctic region: green toads (<Emphasis Type="Italic">Bufo viridis</Emphasis> subgroup) indicate glacial refugia in Eastern Central Asia

The phylogeography of western Palearctic species is relatively well studied, but data on Eastern Central Asia are scarce. We present one of the first data sets from a widespread terrestrial vertebrate (Bufo pewzowi) inhabiting Eastern Central Asian mountains and deserts to gain knowledge on its phylogeography in this region. We applied combined phylogenetic and demographic analyses to understand the evolutionary history using mitochondrial DNA D-loop variation of toads from 37 locations. Genetic structure of Bufo pewzowi is strongly affected by landscape: we found three haplotype groups in eastern Kazakhstan, Dzungaria and Tarim Basin, divided by the Tian Shan and Dzungarian Alatau ranges. A vicariant hypothesis may explain divergence among groups. The divergence time of the three major clades was estimated about 0.9 million years ago (confidence interval 0.5–1.4), and is discussed with respect to Quaternary uplifting and glaciation in the Tian Shan. Demographic analyses provided evidence for both historical bottlenecks and population expansions and suggested Pleistocene signatures. Glacial refugia were inferred in the Tarim Basin (around the Turpan depression), in southern Dzungaria (Urumqui region), at the northern foot of the Tian Shan (Gongnaisi) and perhaps at the Altai range (Terekti). Regional Post-Last Glacial Maximum dispersal patterns are proposed. A taxonomic hypothesis is presented. This study provides a detailed history of how a widespread terrestrial vertebrate responded to geological change and Quaternary glacial events in Eastern Central Asia and may have significance for future phylogeographic research in this understudied region.     

胰升血糖素样肽-1及其受体与 2 型糖尿病的治疗

胰岛素对治疗 2 型糖尿病有一定效果,但长期使用会引起低血糖反应;双胍类药物降糖疗效显著,但会引起消化道不良反应 . 因此,寻找一种安全有效的药物是 2 型糖尿病治疗的当务之急 . 胰升血糖素样肽-1 作为一种胰岛素分泌促进剂和胰岛素增敏剂越来越受人们的关注,将它用于治疗糖尿病不会产生低血糖,对 1 型和 2 型糖尿病都有疗效 . 讨论胰升血糖素样肽-1及其受体的最新研究状况 .     

三峡水库香溪河库湾基于初级生产力的渔产潜力估算

于20132014 年在三峡水库香溪河库湾开展了浮游植物初级生产力的调查, 并分别采用营养动态模型、Cushing 模型、Tait 模型和Downing 模型计算了该库湾滤食性鱼类的渔产潜力, 以此来评估其水体承载量。结果表明, 香溪河库湾初级生产力具有显著的时空异质性;据此计算的渔产潜力显示了空间差异和季节动态;高岚河水域的渔产潜力较其他水域要大;夏季渔产潜力最大, 从大到小依次为春季、秋季、冬季。上述方法计算的滤食性鱼类渔产潜力分别为7.3103、1.046104、1.256104 和2.064106 kg/y。除了Downing模型外, 其他方法的估算结果较接近渔业资源量的真实状况。以3 个模型计算的渔产潜力为核算依据, 确认该库湾滤食性鱼类的水体承载量约为104 kg, 最大持续捕捞量可达5103 kg/y。研究结果可为三峡水库支流库湾渔业资源的可持续利用提供必要的技术支撑。       

石油烃污染对海洋浮游植物群落的短期毒性效应

海上溢油和船舶含油废水排放等石油污染给海洋生态环境带来严峻考验。为了解石油污染对海洋浮游植物的短期群落效应, 于实验室对采自浙江省乐清湾海域的四季浮游植物进行了14天的微宇宙实验研究。通过测定不同浓度原油水溶性成分(water accommodated fraction, WAF)胁迫下浮游植物群落各种类的细胞密度, 发现原油WAF对浮游植物群落的种类数、多样性、均匀度和优势种组成及优势度均有极显著影响。原油污染组的种类数均低于对照组, 多样性指数也总体上低于对照组, 但均匀度指数无明显规律。WAF对各季节浮游植物群落优势种的影响存在季节、浓度梯度和种类差异: 1)在高浓度WAF (≥2.28 mg·L^-1)胁迫下, 各季节浮游植物群落中中肋骨条藻(Skeletonema costatum)的优势度均呈升高趋势, 除秋季外, 长菱形藻(Nitzschia longissima)在其余季节的优势度均显著下降, 另外秋季实验中微小原甲藻(Prorocentrum minimum)的优势度呈先升高后下降的趋势, 秋冬季斜纹藻(Pleurosigma sp.)和念珠直链藻(Melosira moniliformis)的优势度呈下降趋势; 2)在低浓度WAF (≤1.16 mg·L^-1)胁迫下, 除秋季中肋骨条藻仍为绝对优势种外, 其余季节该种微藻的优势度均呈下降趋势, 春、夏季长菱形藻的优势度逐渐升高, 而冬季则是念珠直链藻的优势度不断增加。原油WAF影响下, 可能r策略种将逐渐取代k策略种, 导致浮游植物群落趋于小型化。     

灰飞虱高带毒（RSV）群体酵母双杂交cDNA文库的构建

为了研究灰飞虱Laodelphax striatellus Fallén与水稻条纹病毒（rice stripe virus, RSV）互作机制, 本研究构建了灰飞虱高带毒群体酵母双杂交cDNA文库。以实验室筛选的灰飞虱高带毒群体为材料, 分离纯化mRNA, 反转录合成双链cDNA, 并连接三框型接头, 层析柱分级纯化。采用同源重组反应制备三框型cDNA入门文库, 再通过同源重组将入门文库转移到Gateway兼容载体pGADT7-DEST上, 构建获得酵母双杂交cDNA文库。检测结果表明： 文库库容量为3.68×10⁷ cfu, 扩增文库滴度为2.62×10¹⁰ cfu/mL; 文库重组率大于95%, cDNA插入片段平均长度>1 kb, 达到了标准cDNA文库的要求。灰飞虱高带毒群体酵母双杂交cDNA文库的构建为开展昆虫介体与水稻条纹病毒互作机制的研究奠定了基础。