Comparison of DNA Extraction Protocols and Molecular Targets to Diagnose Tuberculous Meningitis

Elevated Mitochondrial Reactive Oxygen Species within Cerebrospinal Fluid as New Index in the Early Detection of Lumbar Spinal Stenosis

Lumbar spinal stenosis (LSS) is a common neurodegenerative condition. However, how neurogenic claudication develops with severe leg pain has not yet been clearly elucidated. Moreover, cerebrospinal fluid (CSF) physiology at the lumbosacral level is poorly understood because of the difficulties involved in quantification and visualization. Recent studies have suggested that assessment of mitochondrial function in CSF provides an indirect way to assess neurological disorders and an important feature of disease progression. In this study, we assessed the relevance of endogenous extracellular mitochondria in the CSF of rats after LSS. Mitochondrial changes within the CSF were analyzed following LSS at 1 week using flow cytometry. An increase in cell size and number was observed in CSF with LSS, and reactive oxygen species (ROS) levels were also increased within the CSF at 1 week in the LSS group. Elevated mitochondrial ROS and functional changes in the CSF are hallmarks of LSS. The present study is the first to demonstrate that elevated mitochondrial ROS within the CSF is a new index for the early detection of LSS. Moreover, it may represent a potential novel treatment target for LSS.

A Systematic Review and Meta-analysis of the Diagnostic Accuracy of Nucleic Acid Amplification Tests for Tuberculous Meningitis

The diagnosis of tuberculous meningitis (TBM) is difficult and poses a significant challenge to physicians worldwide. Recently, nucleic acid amplification (NAA) tests have shown promise for the diagnosis of TBM, although their performance has been variable. We undertook a systematic review and meta-analysis to evaluate the diagnostic accuracy of NAA tests with cerebrospinal fluid (CSF) samples against that of culture as the reference standard or a combined reference standard (CRS) for TBM. We searched the Embase, PubMed, Web of Science, and Cochrane Library databases for the relevant records. The QUADAS-2 tool was used to assess the quality of the studies. Diagnostic accuracy measures (i.e., sensitivity and specificity) were pooled with a random-effects model. All statistical analyses were performed with STATA (version 14 IC; Stata Corporation, College Station, TX, USA), Meta-DiSc (version 1.4 for Windows; Cochrane Colloquium, Barcelona, Spain), and RevMan (version 5.3; The Nordic Cochrane Centre, the Cochrane Collaboration, Copenhagen, Denmark) software. Sixty-three studies comprising 1,381 cases of confirmed TBM and 5,712 non-TBM controls were included in the final analysis. These 63 studies were divided into two groups comprising 71 data sets (43 in-house tests and 28 commercial tests) that used culture as the reference standard and 24 data sets (21 in-house tests and 3 commercial tests) that used a CRS. Studies which used a culture reference standard had better pooled summary estimates than studies which used CRS. The overall pooled estimates of sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) of the NAA tests against culture were 82% (95% confidence interval [CI], 75 to 87%), 99% (95% CI, 98 to 99%), 58.6 (95% CI, 35.3 to 97.3), and 0.19 (95% CI, 0.14 to 0.25), respectively. The pooled sensitivity, specificity, PLR, and NLR of NAA tests against CRS were 68% (95% CI, 41 to 87%), 98% (95% CI, 95 to 99%), 36.5 (95% CI, 15.6 to 85.3), and 0.32 (95% CI, 0.15 to 0.70), respectively. The analysis has demonstrated that the diagnostic accuracy of NAA tests is currently insufficient for them to replace culture as a lone diagnostic test. NAA tests may be used in combination with culture due to the advantage of time to result and in scenarios where culture tests are not feasible. Further work to improve NAA tests would benefit from the availability of standardized reference standards and improvements to the methodology.

Expression of autophagy-related genes in cerebrospinal fluid of patients with tuberculous meningitis

The expression of autophagy-related genes in cerebrospinal fluid of patients with tuberculous meningitis (TBM) and their clinical significance in patients with TBM was investigated. Sixty patients with TBM (observation group) and twenty healthy volunteers during the same period (control group) were selected and the cerebrospinal fluid was collected. The expression levels of p62, Beclin1 and LC3-II genes in cerebrospinal fluid were detected via semi-quantitative reverse transcription-polymerase chain reaction and patients in observation group were divided into high expression and normal or low expression group on the basis of LC3-II expression levels. On the other hand, the contents of inflammatory factors interleukin-6, −10 (IL-6, −10), and tumor necrosis factor-α (TNF-α) were detected using the enzyme-linked immunosorbent assay kit. The mRNA levels of p62, Beclin1 and LC3-II in cerebrospinal fluid of patients in observation were significantly higher than those in the control group (P<0.01). TUNEL assay showed that the apoptosis level of cerebro-spinal fluid in high expression was obviously lower than that in normal or low expression group (P<0.01); the content of IL-6 and TNF-α in cerebrospinal fluid in high expression was significantly lower than those in normal or low expression group (P<0.01); the content of IL-10 in cerebrospinal fluid in high expression was obviously higher than that in normal or low expression group (P<0.01). Correlation analysis revealed that LC3-II was positively correlated with IL-10, but negatively correlated with IL-6 and TNF-α. The mRNA levels of p62, Beclin1 and LC3-II in cerebrospinal fluid of patients with TBM are increased, there is a correlation between expression levels of autophagy-related genes and inflammatory factors, and the high expression of autophagy-related genes may have a protective effect on patients with TBM.