miR-134-5p靶向抑制PAK3表达增强多发性骨髓瘤细胞的化疗敏感性的研究

摘要 目的：研究miR-134-5p对多发性骨髓瘤（multiple myeloma, MM）化疗敏感性的影响及其可能的作用机制。方法：CCK-8法测定人多发性骨髓瘤细胞KM3及其耐硼替佐米（bortezomib, BTZ）细胞株KM3/BTZ对BTZ的化疗敏感性,RT-PCR法检测KM3和KM3/BTZ细胞株中miR-134-5p和p21活化激酶3（p21 activated kinase 3, PAK3）mRNA的表达,生物信息学软件分析miR-134-5p的靶基因,荧光素酶报告实验进行验证,CCK-8法检测分别抑制miR-134-5p和PAK3后KM3/BTZ的化疗敏感性,Western-blot法检测抑制miR-134-5p后KM3/BTZ细胞株中PAK3蛋白的表达。结果：KM3/BTZ细胞株对BTZ的化疗敏感性显著低于KM3细胞株（P＜0.05）。MiR-134-5p在KM3细胞株的表达显著高于KM3/BTZ细胞株,而PAK3 mRNA在KM3细胞株的表达显著低于KM3/BTZ细胞株（P＜0.05）。PAK3为miR-134-5p的靶基因。MiR-134-5p inhibitor组和PAK3 siRNA组KM3/BTZ细胞株的化疗敏感性显著低于对照组（P＜0.05）。MiR-134-5p inhibitor组PAK3蛋白的相对表达显著高于对照组（P＜0.05）。结论：MiR-134-5p可提高KM3/BTZ细胞株的化疗敏感性,其机制可能与抑制PAK3的表达有关。     

1株多重耐药肺炎克雷伯菌耐药基因和整合子、转座子遗传标记研究

目的 了解多重耐药肺炎克雷伯菌的耐药基因存在状况和遗传学背景。方法 聚合酶链反应(RCR)法对多重耐药的肺炎克雷伯菌进行β-内酰胺酶基因、氨基糖苷类修饰酶基因、质粒AmpC酶基因、qacEΔ1-sull耐消毒剂和磺胺基因、整合子遗传标记(整合酶基因)、Tn21/Tn501转座子遗传标记(汞离子还原酶基因)检测。结果 TEM、SHV型β-内酰胺酶基因, DHA型质粒AmpC酶基因,aac(6′)-1型氮基糖苷类修饰酶基因,qacEΔ1-sul1耐消毒剂和磺胺基因,整合子遗传标记(intI1整合酶基因),Tn21/Tn501转座子遗传标记(merA汞离子还原酶基因)检测阳性。结论 多重耐药肺炎克雷伯菌存在多种耐药基因和Ⅰ类整合子、Tn21/Tn501转座子。     

表达CD19~+CD56~-的多发性骨髓瘤浆细胞免疫表型的鉴别

目的:研究多发性骨髓瘤患者浆细胞和对照组正常浆细胞免疫表型,有效地识别表达CD19+CD56-的多发性骨髓瘤恶性浆细胞。方法:采用四色流式细胞仪(BD,FACSCalibur)检测44例MM患者浆细胞以及25例健康骨髓捐献者正常浆细胞膜上的抗原表达。采用CellQuest软件分析结果。细胞膜表面抗原表达率大于20%定义为表达阳性。阳性率为表达阳性的患者及健康对照者所占百分比。结果:44例MM患者浆细胞免疫表型表达频率为:CD138+:97.72%(43/44)、CD38+:100%(44/44)、CD56+:63.64%(28/44)、CD19-:84.09%(37/44)、CD200+:77.27%(34/44)、CD28+:38.64%(17/44);25例对照组正常浆细胞免疫表型表达频率为:CD138+:100%(25/25)、CD38+:100%(25/25)、CD56-:100%(25/25)、CD19+:96%(24/25)、CD200+:0%(0/25)、CD28+:0%(0/25)。在44例MM患者中,9%(4/44)患者表达CD19+CD56-,利用CD200检测4例表达CD19+CD56-的患者,有3例患者伴有CD200阳性表达,可与正常浆细胞鉴别。结论:CD200有利于鉴别表达CD19+CD56-MM恶性浆细胞与正常浆细胞。     

Wistar大鼠实验性变态反应性脑脊髓炎病理探讨

目的研究缓解-复发型EAE大鼠的基本病理改变。方法对缓解-复发型EAE大鼠进行HE染色、Weil髓鞘染色和改良的Bielschowsky染色,以免疫组化方法标记GFAP和MMP-2、MMP-9。结果组织内可见多个血管周围淋巴细胞浸润呈袖套样分布,伴有大片状脱髓鞘,部分脱失的髓鞘内有炎细胞浸润,轴索呈空泡样缺失,GFAP染色证明在旧病灶的周围部分可见星形胶质细胞增生,MMP-2、MMP-9在血管内皮细胞、细胞外基质、炎细胞及脑(脊)膜内呈阳性表达。结论①缓解-复发型EAE大鼠的组织病理学改变与临床表现一致,有活动性和非活动性病灶并存的现象。②MMP-2、MMP-9在活动性病灶内表达,参与疾病的发生。③缓解-复发型EAE病理改变与MS相似,是理想的动物模型。     

基于成果导向教育理念的“微生物工程工艺与设备”课程教学改革与实践

"微生物工程工艺与设备"课程是生物工程专业的核心课程,具有较强的实践性和应用性。将成果导向教育理念引入到该课程教学改革中,围绕三个方面进行:明确课程培养学生的能力,制定课程的预期学习产出;在预期学习产出的基础上优化教学过程,通过整合教学内容,构建"课堂理论强化—网络教学平台—现场教学—仿真模拟"多元立体化教学平台,强化学生的主体地位,实现预期学习产出;建立合理的学习考评体系,评估学习产出,促进课程持续改进。     

Positioning accuracy of a single-isocenter multiple targets SRS treatment: A comparison between Varian TrueBeam CBCT and Brainlab ExacTrac

PurposeThis study compared the positioning accuracy between cone-beam CT (CBCT) and ExacTrac (ETX) for a single-isocenter multiple target stereotactic radiosurgery (SRS) on two TrueBeam STx systems.MethodsA single-isocenter treatment plan was simulated on an anthropomorphic head phantom with six spherical steel ball bearings (BBs). One of the BBs was chosen to be the isocenter. The five off-isocenter targets were located at various distances from the isocenter. MV portal images were generated to evaluate the deviations between the expected and the real center of the targets after CBCT and ETX positioning, respectively.ResultsThe evaluation of the positioning accuracy for the isocenter target showed that CBCT and ETX positioning provided comparable, sub-millimetric results. Deviations in positioning accuracy were also calculated for all other targets, also showing comparable results for CBCT and ETX. Moreover, our study showed that the deviation between CBCT and ETX positioning were in better agreement for TBSTx1 and deviated slightly higher on TBSTx2 (maximum: 1.23 mm at S/I direction), due to a less perfect alignment between the CBCT coordinate system and the ETX coordinate system on TBSTx2 compared to TBSTx1. This study also showed a correlation between the target positioning accuracy and the distance to the isocenter.ConclusionThe positioning accuracy of ETX and CBCT for targets located at isocenter and off-isocenter locations was compared on two treatment machines and found comparable. Our study highlights the importance of a proper calibration procedure, to ensure correct alignment between the CBCT, ETX and machine coordinate systems.     

Separating distinct structures of multiple macromolecular assemblies from cryo-EM projections

Single particle analysis for structure determination in cryo-electron microscopy is traditionally applied to samples purified to near homogeneity as current reconstruction algorithms are not designed to handle heterogeneous mixtures of structures from many distinct macromolecular complexes. We extend on long established methods and demonstrate that relating two-dimensional projection images by their common lines in a graphical framework is sufficient for partitioning distinct protein and multiprotein complexes within the same data set. The feasibility of this approach is first demonstrated on a large set of synthetic reprojections from 35 unique macromolecular structures spanning a mass range of hundreds to thousands of kilodaltons. We then apply our algorithm on cryo-EM data collected from a mixture of five protein complexes and use existing methods to solve multiple three-dimensional structures ab initio. Incorporating methods to sort single particle cryo-EM data from extremely heterogeneous mixtures will alleviate the need for stringent purification and pave the way toward investigation of samples containing many unique structures.