Pooled analysis of the Xpert MTB/RIF assay for diagnosing tuberculous meningitis.

BACKGROUND: Tuberculous meningitis (TBM) is one of the most serious types of extrapulmonary tuberculosis. However, low sensitivity of culture of cerebrospinal fluid (CSF) increases the difficulty in clinical diagnosis, leading to diagnostic delay, and misdiagnosis. Xpert MTB/RIF assay is a rapid and simple method to detect tuberculosis. However, the efficacy of this technique in diagnosing TBM remains unclear. Therefore, a meta-analysis was conducted to evaluate the diagnostic efficacy of Xpert MTB/RIF for TBM, which may enhance the development of early diagnosis of TBM. METHODS: Relevant studies in the PubMed, Embase, and Web of Science databases were retrieved using the keywords 'Xpert MTB/RIF', 'tuberculous meningitis (TBM)'. The pooled sensitivity, pooled specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, summary receiver operator characteristic curve, and area under the curve (AUC) of Xpert MTB/RIF were determined and analyzed. RESULTS: A total of 162 studies were enrolled and only 14 met the criteria for meta-analysis. The overall pooled sensitivity of Xpert MTB/RIF was 63% [95% confidence interval (CI), 59-66%], while the overall pooled specificity was 98.1% (95% CI, 97.5-98.5%). The pooled values of positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 20.91% (12.71-52.82%), 0.40% (0.32-0.50%), and 71.49% (32.64-156.56%), respectively. The AUC was 0.76. CONCLUSIONS: Xpert MTB/RIF exhibited high specificity in diagnosing TBM in CSF samples, but its sensitivity was relatively low. It is necessary to combine other high-sensitive detection methods for the early diagnosis of TBM. Moreover, the centrifugation of CSF samples was found to be beneficial in improving the sensitivity.

[Effect of baicalin on expression of TLR4 in RAW264.7 cells infected by ESBLs Escherichia coli].

OBJECTIVE: To investigate the effect and mechanism of baicalin against beta-lactamases Escherichia coli (ESBLs E. coli) mediated by toll-like receptor 4 (TLR4) signal transduction pathway. METHOD: The RAW264. 7 cells monolayer pretreated with different concentration of baicalin were inoculated with ESBLs E. coli. The expression of TLR4 mRNA and protein were analyzed by semi-quantitative RT-PCR and Immunofluorescence, respectively. The activity of NF-kappaB was detected by Western blot using total cellular protein. The production of TNF-alpha in supernatant was determined by enzyme linked immunosorbnent assay (ELISA). RESULT: ESBLs E. coli significantly up-regulated the expression levels of TLR4 mRNA and protein in a time-dependent manner, induced the activation of NF-KB in RAW264. 7, enhanced the production of TNF-alpha in supernatant. Baicalin down-regulated the expression of TLR4 mRNA and protein, decreased the activation of NF-KB in RAW264. 7 cells and reduced the production of TNF-alpha in supernatant in a dose-dependent manner. CONCLUSION: Baicailin could inhibit TLR4 signal transduction pathway. The mechanism of baicalin against ESBLs E. coli may be through inhibiting the expression of TLR4 and its signal transduction pathway.

Hierarchical gamma-Al2O3 monoliths with highly ordered 2D hexagonal mesopores in macroporous walls.

Hierarchical gamma-Al2O3 monoliths with interconnected macroporous architecture and highly ordered 2D hexagonal mesostructure have been synthesized by using nonionic triblock copolymer and polyurethane foam as co-templates.