Brilliance型16排螺旋CT的故障分析与维修

针对日常使用中遇到的Brilliance 16排螺旋CT高压系统、机架以及控制器局域网络(CAN)通讯等故障现象进行分析与维修,最终通过更换滤波电容、机架数据采集控制器(DMC)电源以及信号刷等配件得以排除故障。通过对故障准确判断以及合理运用厂家Service模式下的维修工具软件快速解决故障,保障了影像科检查工作的顺利进行,从而提高设备的稳定性。     

靶向MLL1-WDR5蛋白-蛋白相互作用抑制剂的研究进展

Mixed lineage leukemia 1(MLL1)是组蛋白甲基转移酶SET家族的成员之一。MLL1与WDR5、RbBP5、Ash2L和DPY-30组成MLL1甲基转移酶复合物调控组蛋白H3的第4位赖氨酸的甲基化水平，对造血系统的发育和血细胞的更新至关重要。部分白血病患者体内存在因MLL1基因易位而产生的致癌蛋白——MLL1融合蛋白，MLL1融合蛋白在发挥其致癌作用时需要功能完整的MLL1酶复合物，故靶向MLL1-WDR5的蛋白-蛋白相互作用成为治疗MLL1融合型白血病的潜在策略。本文对MLL1-WDR5蛋白-蛋白相互作用的生物学机制、结构信息以及抑制剂进行了系统的总结，并结合已报道数据对该领域进行了展望，以期为后续研究提供参考。     

Redox active or thiol reactive? Optimization of rapid screens to identify less evident nuisance compounds

Compounds that exhibit assay interference or undesirable mechanisms of bioactivity are routinely encountered in assays at various stages of drug discovery. We observed that assays for the investigation of thiol-reactive and redox-active compounds have not been collected in a comprehensive review. Here, we review these assays and subject them to experimental optimization to improve their reliability. We demonstrate the usefulness of our assay cascade by assaying a library of bioactive compounds, chemical probes, and a set of approved drugs. These high-throughput assays should complement the array of wet-lab and in silico assays during the initial stages of hit discovery campaigns to pursue only hit compounds with tractable mechanisms of action.     

ArgD of Mycobacterium tuberculosis is a functional N-acetylornithine aminotransferase with moonlighting function as an effective immune modulator

Mycobacterium tuberculosis (M. tuberculosis) encodes an essential enzyme acetyl ornithine aminotransferase ArgD (Rv1655) of arginine biosynthetic pathway which plays crucial role in M. tuberculosis growth and survival. ArgD catalyzes the reversible conversion of N-acetylornithine and 2 oxoglutarate into glutamate-5-semialdehyde and L-glutamate. It also possesses succinyl diaminopimelate aminotransferase activity and can thus carry out the corresponding step in lysine biosynthesis. These essential roles played by ArgD in amino acid biosynthetic pathways highlight it as an important metabolic chokepoint thus an important drug target. We showed that M. tuberculosis ArgD rescues the growth of ΔargD E. coli grown in minimal media validating its functional importance. Phylogenetic analysis of M. tuberculosis ArgD showed homology with proteins in gram positive bacteria, pathogenic and non-pathogenic mycobacteria suggesting the essentiality of this protein. ArgD is a secretory protein that could be utilized by M. tuberculosis to modulate host innate immunity as its moonlighting function. In-silico analysis predicted it to be a highly antigenic protein. The recombinant ArgD protein when exposed to macrophage cells induced enhanced production of pro-inflammatory cytokines TNF, IL6 and IL12 in a dose dependent manner. ArgD also induced the increased production of innate immune effector molecule NOS2 and NO in macrophages. We also demonstrated ArgD mediated activation of the canonical NFkB pathway. Notably, we also show that ArgD is a specific TLR4 agonist involved in the activation of pro-inflammatory signaling for sustained production of effector cytokines. Intriguingly, ArgD protein treatment activated macrophages to acquire the M1 phenotype through the increased surface expression of MHCII and costimulatory molecules CD80 and CD86. ArgD induced robust B-cell response in immunized mice, validating its antigenicity potential as predicted by the in-silico analysis. These properties of M. tuberculosis ArgD signify its functional plasticity that could be exploited as a possible drug target to combat tuberculosis.     

基于网络药理学和分子对接法探索复方一枝蒿颗粒治疗新型冠状病毒肺炎的潜在分子机制

目的 通过网络药理学及分子对接技术探寻复方一枝蒿颗粒治疗新型冠状病毒肺炎的作用机制。方法 应用TCMSP数据库、BATMAN-TCM数据库及文献收集复方一枝蒿颗粒活性成分及潜在靶点。通过TTD、GeneCards和OMMI数据库检索新型冠状病毒肺炎相关的靶点。将复方一枝蒿颗粒药物靶点和新型冠状病毒肺炎相关基因取交集，使用String数据库构建靶蛋白相互作用（PPI）网络。通过Cytoscape构建“药物–活性成分–靶点基因–疾病”网络。对交集靶点进行GO功能、KEGG通路富集分析。利用Autodock_vina软件对活性成分和靶点进行分子对接。结果 共筛选92个活性成分，1 627个靶点，新型冠状病毒肺炎疾病靶点464个，两者取交集筛选出87个潜在靶点。GO功能富集得到2 040个条目（P＜0.05），与病毒过程、参与共生相互作用的生物过程、活性氧代谢过程的调节、与宿主相互作用的生物过程、病毒生命周期、炎症反应的调节等生物学过程有关。KEGG通路分析共得到150条通路，与新冠肺炎密切相关的有人巨细胞病毒感染、结核、COVID-19、IL-17信号通路等。分子对接结果证实，筛选的靶点受体蛋白与活性成分可以较好地结合。结论 复方一枝蒿颗粒可通过多组分、多靶点和多途径的方式对新型冠状病毒肺炎产生治疗作用。