Nanomechanical In Situ Monitoring of Proteolysis of Peptide by Cathepsin B

Characterization and control of proteolysis of peptides by specific cellular protease is a priori requisite for effective drug discovery. Here, we report the nanomechanical, in situ monitoring of proteolysis of peptide chain attributed to protease (Cathepsin B) by using a resonant nanomechanical microcantilever immersed in a liquid. Specifically, the detection is based on measurement of resonant frequency shift arising from proteolysis of peptides (leading to decrease of cantilever''s overall mass, and consequently, increases in the resonance). It is shown that resonant microcantilever enables the quantification of proteolysis efficacy with respect to protease concentration. Remarkably, the nanomechanical, in situ monitoring of proteolysis allows us to gain insight into the kinetics of proteolysis of peptides, which is well depicted by Langmuir kinetic model. This implies that nanomechanical biosensor enables the characterization of specific cellular protease such as its kinetics.     

Survivin和MMP-9在子宫上皮和间质细胞中的表达与子宫内膜异位症间的关系

目的研究Survivin蛋白和基质金属蛋白酶9（matrix metalloproteinase-9,MMP-9）在子宫腺肌症（ade-nomyosis,AM）、腹壁子宫内膜异位症（abdominal wall endometriosis,AWEMS）、卵巢子宫内膜异位症（ovary endometri-osis,OEMS）的在位、异位内膜的腺上皮细胞和间质细胞中的表达,并与对照组进行比较,探讨其在子宫内膜异位症（endometriosis,EMS）的发生发展中的作用。方法采用免疫组化法检测各组织标本中Survivin和MMP-9的表达。结果 （1）在正常子宫内膜组织中Survivin、MMP-9均呈弱表达或无表达。在EMS三个病例组中,无论是在位内膜还是异位内膜组织Survivin、MMP-9的表达均有不同程度的上调,分别与正常子宫内膜组织表达比较差异有统计学意义（P〈0.05）。（2）在AM、AWEMS、OEMS三个病例组中,仅在增生期异位内膜腺上皮细胞和间质细胞中Sur-vivin、MMP-9的表达分别高于在位内膜同类细胞的表达,差异均有统计学意义（P〈0.05）;分泌期则呈不规律表达。（3）在AM、AWEMS、OEMS三个病例组中,限定相同组织部位、相同细胞类型,增生期与分泌期Survivin、MMP-9的表达水平差异无统计学意义（P〉0.05）且无周期性。（4）在AM、AWEMS、OEMS三个病例组中,限定相同生理期、相同组织部位比较腺上皮细胞与间质细胞Survivin、MMP-9的表达：腺上皮细胞显著高于间质细胞的表达,差异有统计学意义（P〈0.05）。（5）EMS三个病例组之间,限定相同生理期、相同组织部位、相同细胞类型,组间分别比较Survivin或MMP-9的表达水平：Survivin表达差异无统计学意义（P〉0.05）,异位内膜仅分泌期MMP-9在AWEMS腺上皮细胞的表达（4.45±0.18）和AM腺上皮细胞的表达（4.68±0.17）高于OEMS异位内膜腺上皮细胞的表达（2.13±0.12）,差异均有统计学意义（P〈0.05）。结论 Survivin和MMP-9在EMS在位内膜和异位内膜腺上皮细胞和间质细胞中高表达可能是内异症发生发展的重要因素并有协同作用,在位内膜异常是EMS发病的决定性因素,腺上皮细胞高表达在EMS的发生发展中起主导作用,AM、AWEMS、OEMS三个病例组中的生物学特性不同可能受发病诱因、腹腔内环境及多种相关因子影响。     

岷江金丝桃中一个新的间苯三酚类化合物

从岷江金丝桃(Hypericum henryi subsp.uraloides)中分离得到了一个新的问苯三酚类化合物(1),命名为umloidin A.其结构主要通过Ms,1D以及2D NMR等波谱方法鉴定.同时,还得到7个已知化合物.     

弓形虫（Toxoplasma gondii）的PCR检测方法在笼养猕猴群中的应用

目的建立快速、灵敏、特异及检测结果易判断的PCR方法,并应用于大规模猕猴种群的弓形虫常规检测中。同时比较巢式PCR和单一PCR的一致性。方法根据弓形虫保守基因p30（SAG1）设计了内、外两对进行巢式PCR扩增以及B1基因设计一对引物进行单一PCR扩增,将DNA样本进行10倍倍比稀释,以检测巢式PCR反应的灵敏度;并对医学生物学研究所自繁猕猴共150只进行了弓形虫检测。结果巢式PCR检测法检测限度可达10^-3ng/uL,而且方法特异。两种PCR法检测结果基本一致,其中巢式PCR检测阳性率（10％）稍高于单一PCR检测阳性率（8．67％）。结论巢式PCR和一次PCR方法都可应用于猕猴弓形虫的常规检测中,并提示巢式PCR比单一PCR更敏感、检出率更高。     

Pre-Existing HCV Variants Resistant to DAAs and Their Sensitivity to PegIFN/RBV in Chinese HCV Genotype 1b Patients

BackgroundThe efficacy of direct-acting antiviral agents (DAAs) could be attenuated by the presence of resistance-associated variants (RAVs). The aim of this study was to investigate the natural prevalence of RAVs among Chinese HCV genotype 1b patients and analyze the efficacy of pegylated interferon (PegIFN)/ribavirin (RBV) therapy in patients with and without RAVs at baseline.MethodsDirect sequencing of the HCV NS3, NS5A and NS5B regions was performed in baseline serum samples of 117 DAAs-naïve subjects infected with HCV genotype 1b. The efficacy of PegIFN/RBV therapy in patients with and without RAVs at baseline was analyzed by comparing the response rates between patients with RAVs and patients with wild type virus.ResultsThe incidence of RAVs was 8.00% (8/100) in the NS3 region (T54S, n = 1, 1.00%; R117H, n = 5, 5.00%; S122T, n = 1, 1.00%; S174F, n = 1, 1.00%), 29.91% (32/107) in the NS5A region (L28M, n = 12, 11.21%; R30Q, n = 10, 9.35%; L31M, n = 1, 0.93%; P58S, n = 4, 3.74%; Y93H, n = 8, 7.48%) and 98.15% (106/108) in the NS5B region (L159F, n = 1, 0.93%; C316N, n = 103, 95.37%; A421V, n = 6, 5.56%). The response rates to PegIFN/RBV treatment did not differ between patients with or without RAVs in the NS5A region.ConclusionsPre-existing RAVs, including key RAVs, were detected in Chinese DAAs-naïve patients infected with HCV genotype 1b. IFN-based therapy could be a good option for patients with RAVs, especially key RAVs, at baseline.     

植被恢复对黄土区煤矿排土场土壤团聚体特征的影响

目前关于植被恢复对排土场土壤团聚性的影响还不清楚,以植被恢复下黄土区露天煤矿排土场为研究对象,采用湿筛法测定了排土场土壤水稳性团聚体组成,研究了植被恢复类型(草地、灌木)和排土场地形(平台、边坡)对土壤团聚体特征的影响。结果表明:植被恢复促进了排土场水稳性团聚体的形成,平台0—20 cm土层水稳性大团聚体数量(R_(0.25))、平均重量直径(MWD)和几何平均直径(GMD)分别达到31.1%,0.70 mm和0.26 mm,边坡分别达到13.3%,0.37 mm和0.17 mm,均显著高于裸地,分形维数(D)在平台和边坡分别为2.91和2.96,均显著低于裸地;平台土壤团聚性要好于边坡,草地对于平台土壤团聚结构改良效果较好,而灌木对于边坡改良效果较好;排土场土壤有机碳和粘粒含量均与土壤团聚体指标有显著相关性。植被恢复提高了排土场土壤团聚性,植被恢复类型和地形对排土场土壤团聚体特征有显著影响。     

Prevalence of Post-Stroke Cognitive Impairment in China: A Community-Based,Cross-Sectional Study

International hospital-based studies have indicated a high risk of cognitive impairment after stroke, evidence from community-based studies in China is scarce. To determine the prevalence of post-stroke cognitive impairment (PSCI) and its subtypes in stroke survivors residing in selected rural and urban Chinese communities, we conducted a community-based, cross-sectional study in 599 patients accounting for 48% of all stroke survivors registered in the 4 communities, who had suffered confirmed strokes and had undergone cognitive assessments via the Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), and Hachinski Ischemia Scale (HIS). Detection of PSCI was based on scores in these neuropsychological scales. Factors potentially impacting on occurrence of PSCI were explored by comparing demographic characteristics, stroke features, and cardiovascular risk factors between patients with and without PSCI. The overall prevalence of PSCI was 80.97% (95%CI: 77.82%-84.11%), while that of non-dementia PSCI (PSCI-ND) and post-stroke vascular dementia (PSD) was 48.91% (95%CI: 44.91%-52.92%) and 32.05% (95%CI: 28.32%-35.79%), respectively. Prior stroke and complications during the acute phase were independent risk factors for PSCI. The risk of recurrent stroke survivors having PSCI was 2.7 times higher than for first-episode survivors, and it was 3 times higher for those with complications during the acute phase than for those without. The higher prevalence of PSCI in this study compared with previous Chinese studies was possibly due to the combined effects of including rural stroke survivors, a longer period from stroke onset, and different assessment methods. There is an urgent need to recognize and prevent PSCI in stroke patients, especially those with recurrent stroke and complications during the acute phase.     

小菜蛾群体繁殖技术

小菜蛾是世界性十字花科蔬菜的主要害虫 ,也是迄今研究认为抗药性发展最快、最为严重的农业害虫。害虫抗药性以及蔬菜害虫防治技术等方面的研究使小菜蛾成为重要的实验昆虫。本文讨论小菜蛾室内群体繁殖技术的几种方法