This work was carried out on a series of twenty-two (22) benzimidazole derivatives with inhibitory activities against Mycobacterium tuberculosis H37Rv by applying the Quantitative Structure-Activity Relationship (QSAR...This work was carried out on a series of twenty-two (22) benzimidazole derivatives with inhibitory activities against Mycobacterium tuberculosis H37Rv by applying the Quantitative Structure-Activity Relationship (QSAR) method. The molecules were optimized at the level DFT/B3LYP/6-31 + G (d, p), to obtain the molecular descriptors. We used three statistical learning tools namely, the linear multiple regression (LMR) method, the nonlinear regression (NLMR) and the artificial neural network (ANN) method. These methods allowed us to obtain three (3) quantitative models from the quantum descriptors that are, chemical potential (μ), polarizability (α), bond length l (C = N), and lipophilicity. These models showed good statistical performance. Among these, the ANN has a significantly better predictive ability R<sup>2</sup> = 0.9995;RMSE = 0.0149;F = 31879.0548. The external validation tests verify all the criteria of Tropsha et al. and Roy et al. Also, the internal validation tests show that the model has a very satisfactory internal predictive character and can be considered as robust. Moreover, the applicability range of this model determined from the levers shows that a prediction of the pMIC of the new benzimidazole derivatives is acceptable when its lever value is lower than 1.展开更多
【目的】通过分析结核分枝杆菌无毒株H37Ra的全基因组序列,并与H37Rv基因组序列比较,发现pabB和lpdA预测的启动子区发生了突变。我们利用报告基因,确认启动子突变与其基因转录水平的关系,探索结核分枝杆菌H37Ra毒力丧失的内在原因。【...【目的】通过分析结核分枝杆菌无毒株H37Ra的全基因组序列,并与H37Rv基因组序列比较,发现pabB和lpdA预测的启动子区发生了突变。我们利用报告基因,确认启动子突变与其基因转录水平的关系,探索结核分枝杆菌H37Ra毒力丧失的内在原因。【方法】利用生物信息学方法预测这两对基因的启动子区,采用PCR技术克隆这两对基因的启动子,与分枝杆菌启动子探针载体pMC210相连,DNA测序证实连接片段正确后,用电穿孔法将重组质粒转化至耻垢分枝杆菌mc2155。利用Quantitative Real-Time RT-PCR检测报告基因lacZ转录水平的差异,进一步验证这两对基因启动子的突变对相应基因转录水平的影响。【结果】Quantitative Real Time PCR检测结果显示H37RapabB启动子活性是H37Rv pabB启动子活性的6倍(p<0.05),而H37Rv lpdA启动子的活性是H37RalpdA启动子的2倍(p<0.05)。【结论】pabB,lpdA的启动子在H37Ra中的突变对其启动子的活性产生了影响,其中lpdA启动子的突变可能与结核分枝杆菌H37Ra的毒力丧失有关。展开更多
目的建立H37Rv结核分支杆菌诱导的兔脊柱结核模型。方法选择未致敏处理的新西兰大白兔48只,在第5腰椎近椎间盘处钻孔,并填充明胶海绵,注射0.5 mg/0.1 m L结核菌悬液,术后观察新西兰大白兔一般情况,并用影像学、组织病理学、细菌学等检...目的建立H37Rv结核分支杆菌诱导的兔脊柱结核模型。方法选择未致敏处理的新西兰大白兔48只,在第5腰椎近椎间盘处钻孔,并填充明胶海绵,注射0.5 mg/0.1 m L结核菌悬液,术后观察新西兰大白兔一般情况,并用影像学、组织病理学、细菌学等检查对兔脊柱结核模型进行评估。结果受H37Rv结核菌株感染后的新西兰大白兔,局部反应较明显,全身反应较轻。48只兔中38只兔完成实验,10只因死亡、术后截瘫被淘汰,15只兔分别于术后第5、6周出现进食欠佳、消瘦,但生命体征平稳,其中4只术区局部肿胀,6只出现下肢运动障碍;其余23只兔术后进食较好,体质量未见明显变化。术后3个月行外科手术,暴露致病兔椎体,38只兔中29只兔椎体可见虫噬样改变,9只兔椎体未见明显变化。术中取脓肿形成的兔脓液培养示结核分枝杆菌生长;取周围软组织、脓壁行苏木精-伊红色(HE)染色,示坏死灶形成、较多炎细胞聚集、淋巴细胞、较少上皮样细胞,骨结构紊乱或消失。建立模型成功率为76.3%(29/38)。结论使用0.5 mg/0.1 m L的H37Rv标准菌株感染的新西兰白兔结核模型建立成功。展开更多
文摘This work was carried out on a series of twenty-two (22) benzimidazole derivatives with inhibitory activities against Mycobacterium tuberculosis H37Rv by applying the Quantitative Structure-Activity Relationship (QSAR) method. The molecules were optimized at the level DFT/B3LYP/6-31 + G (d, p), to obtain the molecular descriptors. We used three statistical learning tools namely, the linear multiple regression (LMR) method, the nonlinear regression (NLMR) and the artificial neural network (ANN) method. These methods allowed us to obtain three (3) quantitative models from the quantum descriptors that are, chemical potential (μ), polarizability (α), bond length l (C = N), and lipophilicity. These models showed good statistical performance. Among these, the ANN has a significantly better predictive ability R<sup>2</sup> = 0.9995;RMSE = 0.0149;F = 31879.0548. The external validation tests verify all the criteria of Tropsha et al. and Roy et al. Also, the internal validation tests show that the model has a very satisfactory internal predictive character and can be considered as robust. Moreover, the applicability range of this model determined from the levers shows that a prediction of the pMIC of the new benzimidazole derivatives is acceptable when its lever value is lower than 1.
文摘【目的】通过分析结核分枝杆菌无毒株H37Ra的全基因组序列,并与H37Rv基因组序列比较,发现pabB和lpdA预测的启动子区发生了突变。我们利用报告基因,确认启动子突变与其基因转录水平的关系,探索结核分枝杆菌H37Ra毒力丧失的内在原因。【方法】利用生物信息学方法预测这两对基因的启动子区,采用PCR技术克隆这两对基因的启动子,与分枝杆菌启动子探针载体pMC210相连,DNA测序证实连接片段正确后,用电穿孔法将重组质粒转化至耻垢分枝杆菌mc2155。利用Quantitative Real-Time RT-PCR检测报告基因lacZ转录水平的差异,进一步验证这两对基因启动子的突变对相应基因转录水平的影响。【结果】Quantitative Real Time PCR检测结果显示H37RapabB启动子活性是H37Rv pabB启动子活性的6倍(p<0.05),而H37Rv lpdA启动子的活性是H37RalpdA启动子的2倍(p<0.05)。【结论】pabB,lpdA的启动子在H37Ra中的突变对其启动子的活性产生了影响,其中lpdA启动子的突变可能与结核分枝杆菌H37Ra的毒力丧失有关。
文摘目的建立H37Rv结核分支杆菌诱导的兔脊柱结核模型。方法选择未致敏处理的新西兰大白兔48只,在第5腰椎近椎间盘处钻孔,并填充明胶海绵,注射0.5 mg/0.1 m L结核菌悬液,术后观察新西兰大白兔一般情况,并用影像学、组织病理学、细菌学等检查对兔脊柱结核模型进行评估。结果受H37Rv结核菌株感染后的新西兰大白兔,局部反应较明显,全身反应较轻。48只兔中38只兔完成实验,10只因死亡、术后截瘫被淘汰,15只兔分别于术后第5、6周出现进食欠佳、消瘦,但生命体征平稳,其中4只术区局部肿胀,6只出现下肢运动障碍;其余23只兔术后进食较好,体质量未见明显变化。术后3个月行外科手术,暴露致病兔椎体,38只兔中29只兔椎体可见虫噬样改变,9只兔椎体未见明显变化。术中取脓肿形成的兔脓液培养示结核分枝杆菌生长;取周围软组织、脓壁行苏木精-伊红色(HE)染色,示坏死灶形成、较多炎细胞聚集、淋巴细胞、较少上皮样细胞,骨结构紊乱或消失。建立模型成功率为76.3%(29/38)。结论使用0.5 mg/0.1 m L的H37Rv标准菌株感染的新西兰白兔结核模型建立成功。
