莫西沙星联合纤维支气管镜药物灌注对耐多药肺结核患者T细胞亚群、肺功能和肝功能的影响

摘要 目的：探讨莫西沙星联合纤维支气管镜药物灌注对耐多药肺结核患者T细胞亚群、肺功能和肝功能的影响。方法：选取2017年2月~2018年12月期间我院收治的90例耐多药肺结核患者,根据随机数字表法分为对照组（n=45,常规基础治疗）和研究组（n=45,莫西沙星联合纤维支气管镜药物灌注）,比较两组患者痰菌转阴率、病灶吸收率、T细胞亚群、肺功能和肝功能。结果：研究组治疗6个月后的痰菌转阴率为88.89%（40/45）,高于对照组的68.89%（31/45）（P<0.05）。研究组治疗6个月后的病灶吸收率为84.44%（38/45）,高于对照组的64.44%（29/45）（P<0.05）。两组治疗6个月后第1 s用力呼气容积（FEV₁）、用力肺活量（FVC）、每分钟最大通气量（MVV）占预计值百分比、总蛋白(TP)、CD4⁺、CD4⁺/CD8⁺均升高,且研究组高于对照组（P<0.05）;丙氨酸氨基转移酶(ALT)、门冬氨酸氨基转移酶(AST)、CD8⁺均降低,且研究组低于对照组（P<0.05）。结论：莫西沙星联合纤维支气管镜药物灌注治疗耐多药肺结核,可有效阻止疾病进展,同时在改善患者T细胞亚群、肺功能和肝功能方面效果显著。     

6MWT在评价老年肺结核应用及与血气分析相关性

摘要 目的：探究6分钟步行试验（6-minute walk test,6MWT）在评价老年肺结核患者病情中的应用,并分析6MWT同肺结核患者血气指标的相关性。方法：选择2019年1月至2019年12月于我院接受治疗的200例高龄肺结核患者为实验组,另选取同期于我院接受体格检查的50例健康个体为对照组,分别对两组患者实施6MWT实验,测量两组个体的步行距离、实验前后血氧饱和度（SpO₂）,计算SpO₂下降率,并对所有实验组患者实施肺功能实验,评估肺功能相关指标同6MWT相关性。结果：（1）对比显示实验组患者的6MWT、SpO₂、PaO₂明显低于对照组,PaCO₂高于对照组（P<0.05）;（2）实验前后比较显示实验组患者试验后的SpO₂、PaO₂低于实验前,PaCO₂高于实验前（P<0.05）;（3）相关性分析显示,实验组患者的6MWT同FEV1、FEV1/FVC呈正相关（P<0.05）;（4）相关性分析显示实验组患者的6MWT同SpO₂、PaO₂呈正相关,同PaCO₂呈负相关（P<0.05）。结论：6MWT同高龄肺结核患者肺功能及血气相关指标存在明显的相关性,可将6MWT作为老年肺结核患者病情评估指标之一。     

应用GeneXpert MTB/RIF对肺外结核的快速检测及评估

目的评估GeneXpert MTB/RIF检测肺外结核分枝杆菌的准确性,并与传统方法进行比较。方法选取2016年6月至2017年6月在本院就诊的144例疑似肺外结核病患者,对所有标本分别进行金胺“O”荧光染色镜检、液体培养及药敏试验、固体培养及比例法体外药敏试验和Xpert法检测。结果收集的144例疑似肺外结核标本中,确诊108例,以胸水、淋巴结活检和脓液感染较多,另36例阴性患者中,10例为非结核分枝杆菌感染。Xpert试验的敏感性为28.73%,特异性为96.00%,其阳性预测值和阴性预测值均高于其他3种检测方法。在阳性检出率方面,Xpert试验高于涂片镜检(χ~2=17.39,P0.05)、低于液体培养(χ~2=8.64,P0.05),而与固体培养之间差异无统计学意义(χ~2=2.56,P0.05)。固体培养、液体培养和Xpert试验3种方法对结核分枝杆菌利福平耐药率检测差异无统计学意义(P0.05),耐药率分别为8.33%、9.68%和11.11%,且Xpert试验方法检测出2株耐多药结核分枝杆菌,平均耗时2.5 h。结论 GeneXpert MTB/RIF可以作为一种筛选及快速检测工具应用于肺外结核的诊断,同时可作为检测MDR-TB的一种指标。     

Structural insights of PA-824 derivatives: ligand-based 3D-QSAR study and design of novel PA824 derivatives as anti-tubercular agents

Abstract

With the purpose of designing novel chemical entities with improved inhibitory potencies against drug-resistant Mycobacterium tuberculosis, the 3D- quantitative structure–activity relationship (QSAR) studies were carried out on biphenyl analogs of the tuberculosis (TB) drug, PA-824. Anti-mycobacterial activity (MABA) was considered for the 3D-QSAR studies using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) approaches. The best CoMFA and CoMSIA models were found statistically significant with cross-validated coefficients (q²) of 0.784 and 0.768, respectively, and conventional coefficients (r²) of 0.823 and 0.981, respectively. The cross-validated and the external validation results revealed that both the CoMFA and CoMSIA models possesses high accommodating capacities and they would be reliable for predicting the pMIC values of new PA-824 derivatives. Based on the models and structural insights, a series of new PA-824 derivatives were designed and the anti-mycobacterial activities of the designed compounds were predicted based on the best 3D-QSAR model. The predicted data results suggest the designed compounds are more potent than existed ones.     

Antimycobacterial activity: synthesis of novel 3-(substituted phenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues

In this study, a series of novel 3-(substituted phenyl)-6,7-dimethoxy-3a,4-dihydro-3H-indeno[1,2-c]isoxazole analogues were synthesized and evaluated for antimycobacterial activity against Mycobacterium tuberculosis (MTB) H₃₇Rv and isoniazid resistant M. tuberculosis (INHR-MTB). All the newly synthesized compounds were showing moderate to high inhibitory activities. The compound 6,7-dimethoxy-3-(4-chloro phenyl)-4H-indeno[1,2-c]isoxazole (4b) was found to be the most promising compound, active against MTB H₃₇Rv and INHR-MTB with minimum inhibitory concentrations of 0.22 and 0.34 μM.     

Synthesis of some 4-arylidenamino-4H-1,2,4-triazole-3-thiols and their antituberculosis activity

The increasing clinical importance of drug-resistant mycobacterial pathogens has lent additional urgency to microbiological research and new antimycobacterial compound development. For this purpose, new triazoles were synthesized and evaluated for antituberculosis activity. A series of 4-arylidenamino-4H-1,2,4-triazole-3-thiol derivatives (2a–n) were synthesized from the treatment of 4-amino-4H-1,2,4-triazoles-3-thiol (1) with the respective aldehydes and were evaluated for antituberculosis activity against Mycobacterium tuberculosis H₃₇Rv (ATCC 27294), using the BACTEC 460 radiometric system and BACTEC 12B medium. Compound 2k showed an intereting activity at 6.25 μg/mL with a 87 percentage inhibition.     

Dihalogenated sulfanilamides and benzolamides are effective inhibitors of the three β-class carbonic anhydrases from Mycobacterium tuberculosis

A series of halogenated sulfanilamides and halogenated benzolamide derivatives have been investigated as inhibitors of three β-carbonic anhydrases (CAs, EC 4.2.1.1) from the bacterial pathogen Mycobacterium tuberculosis, mtCA 1 (Rv1284), mtCA 2 (Rv3588c) and mtCA 3 (Rv3273). All three enzymes were inhibited with efficacies between the submicromolar to the micromolar one, depending on the substitution pattern at the sulfanilamide moiety/fragment of the molecule. Best inhibitors were the halogenated benzolamides (K_Is in the range of 0.12–0.45 μM) whereas the halogenated sulfanilamides were slightly less inhibitory (K_Is in the range of 0.41–4.74 μM). This class of β-CA inhibitors may have the potential for developing antimycobacterial agents with a diverse mechanism of action compared to the clinically used drugs for which many strains exhibit multi-drug/extensive multi-drug resistance.     

The AMPK-PPARGC1A pathway is required for antimicrobial host defense through activation of autophagy

AMP-activated protein kinase (AMPK) is a crucial energy sensor and plays a key role in integration of cellular functions to maintain homeostasis. Despite this, it is largely unknown whether targeting the AMPK pathway can be used as a therapeutic strategy for infectious diseases. Herein, we show that AMPK activation robustly induces antibacterial autophagy, which contributes to antimicrobial defense against Mycobacterium tuberculosis (Mtb). AMPK activation led to inhibition of Mtb-induced phosphorylation of the mechanistic target of rapamycin (MTOR) in macrophages. In addition, AMPK activation increased the genes involved in oxidative phosphorylation, mitochondrial ATP production, and biogenesis in Mtb-infected macrophages. Notably, peroxisome proliferator-activated receptor-gamma, coactivator 1α (PPARGC1A) was required for AMPK-mediated antimicrobial activity, as well as enhancement of mitochondrial function and biogenesis, in macrophages. Further, the AMPK-PPARGC1A pathway was involved in the upregulation of multiple autophagy-related genes via CCAAT/enhancer binding protein (C/EBP), β (CEBPB). PPARGC1A knockdown inhibited the AMPK-mediated induction of autophagy and impaired the fusion of phagosomes with MAP1LC3B (LC3B) autophagosomes in Mtb-infected macrophages. The link between autophagy, mitochondrial function, and antimicrobial activity was further demonstrated by studying LysMCre-mediated knockout of atg7, demonstrating mitochondrial ultrastructural defects and dysfunction, as well as blockade of antimicrobial activity against mycobacteria. Collectively, our results identify the AMPK-PPARGC1A axis as contributing to autophagy activation leading to an antimicrobial response, as a novel host defense mechanism.     

Cover Image,Volume 88, Issue 6

Hsp16.3, a molecular chaperone, plays a vital role in the growth and survival of Mycobacterium tuberculosis inside the host. We previously reported that deletion of three amino acid residues (¹⁴²STN¹⁴⁴) from C-terminal extension (CTE) of Hsp16.3 triggers its structural perturbation and increases its chaperone activity, which reaches its apex upon the deletion of its entire CTE (¹⁴¹RSTN¹⁴⁴). Thus, we hypothesized that Arg141 (R141) and Ser142 (S142) in the CTE of Hsp16.3 possibly hold the key in maintaining its native-like structure and chaperone activity. To test this hypothesis, we generated two deletion mutants in which R141 and S142 were deleted individually (Hsp16.3ΔR141 and Hsp16.3ΔS142) and three substitution mutants in which R141 was replaced by lysine (Hsp16.3R141K), alanine (Hsp16.3R141A), and glutamic acid (Hsp16.3R141E), respectively. Hsp16.3ΔS142 or Hsp16.3R141K mutant has native-like structure and chaperone activity. Deletion of R141 from the CTE (Hsp16.3ΔR141) perturbs the secondary and tertiary structure, lowers the subunit exchange dynamics and decreases the chaperone activity of Hsp16.3. But, the substitution of R141 with alanine (Hsp16.3R141A) or glutamic acid (Hsp16.3R141E) perturbs its secondary and tertiary structure. Surprisingly, such charge tampering of R141 enhances the subunit exchange dynamics and chaperone activity of Hsp16.3. Interestingly, neither the deletion of R141/S142 nor the substitution of R141 with lysine, alanine and glutamic acid affects the oligomeric mass/size of Hsp16.3. Overall, our study suggests that R141 (especially the positive charge on R141) plays a crucial role in maintaining the native-like structure as well as in regulating subunit exchange dynamics and chaperone activity of Hsp16.3.