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e To explore the phenotypic and genotypic characterization of pyrazinamide (PZA) resistance among multidrug-resistant Mycobacterium tuberculosis (MDR-TB) isolates in Zhejiang province, a total of 274 MDR-TB isolates were collected. Drug susceptibility testing and spoligotyping were performed on all clinical isolates. In addition, the mutated features of PZA-resistant loci, including pncA and rpsA, were also analyzed by DNA sequencing. Our results showed that the prevalence of PZA resistance among MDR-TB strains in Zhejiang province was 43.07% and that PZA resistance was associated with concomitant resistance to streptomycin. The majority of PZA-resistant MDR-TB isolates belonged to the Beijing family. Mutations within pncA, not rpsA, constituted the primary mechanism of PZA resistance. Among 118 PZA-resistant isolates, 53 different mutations were observed in pncA, and most of them were point mutations. Compared with the phenotypic data, DNA sequencing of pncA has sensitivity and specificity of 77.97% and 96.79%, respectively. Analysis of pncA provided a robust tool for rapid detection of PZA drug resistance.

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BackgroundPreclinical data suggest that oncogene (EGFR and KRAS) events regulate tumor procoagulant activity. However, few studies have prospectively investigated the clinical relevance between the presence of EGFR or KRAS mutations and occurrence of venous thromboembolism(VTE) in patients with non-small cell lung cancer (NSCLC).MethodsA total of 605 Chinese patients with newly diagnosed NSCLC were included and were followed for a maximum period of 4.5 years. EGFR and KRAS mutations were determined by amplification refractory mutation system polymerase chain reaction method at inclusion. The main outcome was objectively confirmed VTE.ResultsOf the 605 patients, 40.3% (244) had EGFR mutations and 10.2% (62) of patients had KRAS mutations. In multivariable analysis including age, sex, tumor histology, tumor stage, performance status, EGFR and KRAS status, EGFR wild-type (sub-distribution hazard ratio 1.81, 95% confidence interval 1.07–3.07) were associated with the increased risk of VTE. In competing risk analysis, the probability of developing VTE was 8.3% in those with and 13.2% in those without EGFR mutations after 1 year; after 2 years, the corresponding risks were 9.7 and 15.5% (Gray test P = 0.047).ConclusionsEGFR mutations have a negative association with the risk of VTE in Chinese patients with NSCLC.