重组含有Epstein-Barr病毒潜伏膜蛋白1(LMP1)基因的杆状病毒在昆虫细胞中的表达

用杆状病毒表达系统重组病毒,在昆虫细胞中表达了完整的含有ＥＢＶ－ＬＭＰ１基因３个外显子开放读码框架的长２．３ｋｂ的ｃＤＮＡ片段。用重组病毒感染Ｓｆ９细胞,用免疫荧光染色,结果表明：４８小时表达重组蛋白,７２小时细胞较完整,免疫荧光染色强阳性,９６小时后细胞出现破碎。我们采集７２小时的组织培养上清和细胞破碎裂解液,分别采用ＳＤＳ－ＰＡＧＥ、ＨＰＬＣ分子筛法,用免疫蛋白印迹法实验证明,表达的蛋白能被抗ＬＭＰ１的单克隆抗体所识别,测定表达蛋白的分子量为６０ｋＤ。经蛋白含量扫描图分析,采用Ｓｅｐｈａｄｅｘ－７５柱初步纯化表达的ＬＭＰ１蛋白,将后者进行裸鼠体内致瘤实验,未见肿瘤生长。     

HBIG,无环鸟苷,干扰素联合对慢性乙型肝炎抗病毒效应观察

本文报道血清ＨＢＶ复制标志阳性的慢乙肝５４例,随机分为治疗组及对照组各２７例进行ＨＢＩＧ、无环鸟苷、干扰素联合近、远期抗病毒效应观察。治疗组为无环鸟苷第一周按２５～２０ｍｇ／ｋｇ／ｄ计后改１７～１５ｍｇ／ｋｇ／ｄ×５３天,共６０天;人白细胞干扰素１×１０６Ｕ肌注每周３次×４周,后改１．０×１０６Ｕ肌注每周２次×６周,共１０周;ＨＢＩＧ４００Ｕ肌注隔日１次,共１０周,对照组仅给予一般“保肝”药物。其中治疗组１８例,对照组１９例进行治后半年到２年追踪观察,结果近、远期ＨＢｃＡｇ、ＤＮＡＰ、ＨＢＶ－ＤＮＡ阴转率治疗组均高于对照组,其中治疗组近、远期ＨＢｃＡｇ,ＨＢＶ－ＤＮＡ阴转率均达４０％以上,明显高于对照组（Ｐ＜０．０５～０．０１）,治疗组近、远期各有４例及２例ＨＢｓＡｇ阴转,而对照组则无一例阴转,从近、远期综合抗病毒效应观察,治疗组全阴率分别为３３．３％、４４．４％,而对照组分别为３．７９％及０％,Ｐ＜０．０１,治疗组无明显毒副反应。对比单用无环鸟苷,全阴率３１．８％;无环鸟苷加干扰素两药联合全阴率３７．５％,均有所提高,达到４４．４％,值得进一步研究。     

Measles Contributes to Rheumatoid Arthritis: Evidence from Pathway and Network Analyses of Genome-Wide Association Studies

Growing evidence from epidemiological studies indicates the association between rheumatoid arthritis (RA) and measles. However, the exact mechanism for this association is still unclear now. We consider that the strong association between both diseases may be caused by shared genetic pathways. We performed a pathway analysis of large-scale RA genome-wide association studies (GWAS) dataset with 5,539 cases and 20,169 controls of European descent. Meanwhile, we evaluated our findings using previously identified RA loci, protein-protein interaction network and previous results from pathway analysis of RA and other autoimmune diseases GWAS. We confirmed four pathways including Cytokine-cytokine receptor interaction, Jak-STAT signaling, T cell receptor signaling and Cell adhesion molecules. Meanwhile, we highlighted for the first time the involvement of Measles and Intestinal immune network for IgA production pathways in RA. Our results may explain the strong association between RA and measles, which may be caused by the shared genetic pathway. We believe that our results will be helpful for future genetic studies in RA pathogenesis and may significantly assist in the development of therapeutic strategies.     

Ca^2＋与细胞凋亡

Ｃａ＾２＋在某些因素诱导的细胞凋亡中起着重要信使作用。细胞内Ｃａ＾２＋浓度上升可来源于胞外Ｃａ＾２＋内汉、内库钙动员或者二者兼之。     

Nitro as a novel zinc-binding group in the inhibition of carboxypeptidase A

2-Substituted 3-nitropropanoic acids were designed and synthesized as inhibitors against carboxypeptidase A (CPA). (R)-2-Benzyl- 3-nitropropanoic acid showed a potent inhibition against CPA (K(i)=0.15 microM). X-ray crystallography discloses that the nitro group well mimics the transition state occurred in the hydrolysis catalyzed by CPA, that is, an O,O'-bidentate coordination to the zinc ion and the two respective hydrogen bonds with Glu-270 and Arg-127. Because the nitro group is a planar species, we proposed (R)-2-benzyl-3-nitropropanoic acid as a pseudo-transition-state analog inhibitor against CPA.     

A Fully Verified Theoretical Analysis of Contact‐Mode Triboelectric Nanogenerators as a Wearable Power Source

Harvesting mechanical energy from human activities by triboelectric nanogenerators (TENGs) is an effective approach for sustainable, maintenance‐free, and green power source for wireless, portable, and wearable electronics. A theoretical model for contact‐mode triboelectric nanogenerators based on the principles of charge conservation and zero loop‐voltage is illustrated. Explicit expressions for the output current, voltage, and power are presented for the TENGs with an external load of resistance. Experimental verification is conducted by using a laboratory‐fabricated contact‐mode TENG made from conducting fabric electrodes and polydimethylsiloxane/graphene oxide composite as the dielectric layer. Excellent agreements of the output voltage, current, and power are demonstrated between the theoretical and experimental results, without any adjustable parameters. The effects of the moving speed on output voltage, current, and power are illustrated in three cases, that is, the motion with constant speed, the sinusoidal motion cycles, and the real walking cycles by human subject. The fully verified theoretical model is a very powerful tool to guide the design of the device structure and selection of materials, and optimization of performance with respect to the application conditions of TENGs.     

Demographic controls of aboveground forest biomass across North America

Ecologists have limited understanding of how geographic variation in forest biomass arises from differences in growth and mortality at continental to global scales. Using forest inventories from across North America, we partitioned continental‐scale variation in biomass growth and mortality rates of 49 tree species groups into (1) species‐independent spatial effects and (2) inherent differences in demographic performance among species. Spatial factors that were separable from species composition explained 83% and 51% of the respective variation in growth and mortality. Moderate additional variation in mortality (26%) was attributable to differences in species composition. Age‐dependent biomass models showed that variation in forest biomass can be explained primarily by spatial gradients in growth that were unrelated to species composition. Species‐dependent patterns of mortality explained additional variation in biomass, with forests supporting less biomass when dominated by species that are highly susceptible to competition (e.g. Populus spp.) or to biotic disturbances (e.g. Abies balsamea).     

Microtubule and microfilament distribution and tubulin content in the cell cycle of Indian muntjac cells

Using DAPI, rabbit antitubulin antibody, FITC-labeled goat anti-rabbit IgG, and TRITC-phalloidin to stain individual cells, the microspectrophotometric analysis showed that three markers that represent the nucleus, microtubules (MT), and microfilaments (MF), respectively, could be recognized in individual cells without interference. The phase of the cell cycle was determined by DNA content. We found that in Indian muntjac (IM) cells, the amount of tubulin in G2 and M phases was about twice as much as that in G1 phase. In G2 cells, the cytoplasmic microtubule complex (CMTC) became denser than in G1 cells. The cytoplasmic MT extent in basically the same orientation as MF bundles in interphase. The regions where the MT is denser also have a denser MF distribution.     

The Expression Alteration of BC1 RNA and its Interaction with Eukaryotic Translation Initiation Factor eIF4A Post-Status Epilepticus

Abnormal dendritic sprouting and synaptic remodelling are important pathological features of temporal lobe epilepsy. BC1 RNA is a translation repressor involved in the regulation of the dendritic protein synthesis and mRNA transport, which is essential for dendritic development and plasticity. The expression alteration of BC1 RNA in the pilocarpine induced epilepsy model remains unknown. It is unclear if the interactions between BC1 RNA and eukaryotic initiation factor 4A (eIF4A) exists in this model. The purpose of this study was to investigate the expression changes of BC1 RNA and its interactions with eIF4A post-status epilepticus (SE). Chloride lithium and pilocarpine were used to induce the SE rat model. Either a whole brain or hippocampus tissues were collected at different time points after SE. The expression patterns of BC1 was detected by qPCR and in situ hybridization. The levels of eIF4AI/II protein expression were analyzed via western blotting and immunohistochemistry. The BC1 RNA-eIF4AI/II interaction was determined by electrophoretic mobility shift assay (EMSA). We found that the BC1 RNA levels decreased in hippocampus 3d, 1w and 2w post-SE before the levels recovered. The eIF4AI/II began to rise 3d post-SE and reached the maximum level 1w post-SE. After 1w post-SE the levels decreased in the hippocampal CA1, CA3 and DG subregions. EMSA analysis showed that BC1 RNA specifically interacted with the eIF4AI/II. The BC1 RNA-eIF4AI/II complex reduced to the lowest level 1w post-SE. Our results suggested that BC1 has a negative regulatory correlation with eIF4AI/II, where BC1 RNA could be involved in epileptogenesis by regulating dendritic protein synthesis.