Systematic evaluation of line probe assays for the diagnosis of tuberculosis and drug-resistant tuberculosis.

BACKGROUND: Line probe assays (LPAs) are PCR-based assays used for the rapid diagnosis of Mycobacterium tuberculosis (MTB) and drug-resistant tuberculosis (DR-TB). But studies on its performance are insufficient. Thus, in this study, we conducted a systematic review and meta-analysis to evaluate the effect of LPAs in the detection of MTB and drug-resistant TB in comparison with the traditional culture and DST methods. METHODS: A systemic literature search was conducted on the Web of Science, Embase, PubMed, the Cochrane Library, Scopus, and OVID databases. All the included studies were classified according to different detecting objects. Sensitivity, specificity, Positive Likely Ratio (PLR), Negative Likely Ratio (NLR), Diagnostic Odds Ratio (DOR), corresponding 95% confidence interval, Area Under Curve (AUC), Deeks' funnel plot, and Bivariate Boxplot was used to do the evaluation. RESULTS: 147 studies included 491 datasets, with 182,448 samples, were incorporated into our analysis. The sensitivity (95% CI), specificity (95% CI), PLR, NLR, DOR and AUC for MTB were 0.89 (0.86 to 0.92), 0.94 (0.90 to 0.97), 15.70, 0.11, 139 and 0.96, respectively; for rifampicin-resistant TB were 0.96 (0.95 to 0.97), 0.99 (0.98 to 0.99), 82.9, 0.04, 1994 and 1.00, respectively; for isoniazid-resistant TB were 0.91 (0.89 to 0.93), 0.99 (0.98 to 0.99), 83.4, 0.09, (0.99 to 1.00), 195.7, 0.07, 2783 and 1.00, respectively; for Multi-drug resistant TB (MDR-TB) were 0.93 (0.90 to 0.95), 1.00 (0.99 to 1.00), 195.7, 0.07, 2783 and 1.00, respectively; for extensively drug-resistant TB (XDR-TB) were 0.60 (0.33 to 0.82), 1.00 (0.95 to 1.00), 291.3, 0.4, 726 and 0.95, respectively; for (second-line drug-resistant TB) SLID-TB were 0.83 (0.78 to 0.87), 0.98 (0.97 to 0.99), 44.6, 0.17, 262 and 0.98, respectively. Sensitivity in pre-extensively drug-resistant TB (Pre-XDR-TB) was 0.67, specificity was 0.91. No publication bias existed according to Deeks' funnel plot. CONCLUSION: High diagnosis performance was confirmed in LPAs for the diagnosis of MTB and drug-resistant TB. LPAs might be a good alternative to culture and DST in detecting MTB, RR-TB, INH-TB, XDR-TB, SLID-TB, and MDR-TB. While more studies were still needed to explore the diagnosis performance of LPAs for Pre-XDR TB.

Preparation and conformational analysis of polyproline tri-helix macrocycle nanoscaffolds of varied sizes.

Ligand patterns at the nanoscale are essential in modulating biological recognition and signaling through binding to receptor oligomers. Biocompatible nanoscaffolds that allow precise control of multiple ligand presentation would be of great use in manipulating cellular processes and understanding membrane receptor biology. We have previously developed tri-helix and tetra-helix macrocycle scaffolds based on the Pro9 peptide helix to control ligand arrangements that can selectively target receptor oligomers. A better understanding of the structure of these macromolecules would significantly reduce the difficulty in designing matching ligand positions for target receptors. In this work, we expand the arsenal of ligand patterns by preparing polyproline tri-helix macrocycle scaffolds of different sizes. These synthetic nanoscaffolds composed of peptide helices ranging from Pro6 to Pro12 also allowed us to systematically investigate their properties. With a combination of circular dichroism spectroscopy and ion mobility spectrometry-mass spectrometry (IMS-MS), the measurement for varied sizes of these scaffolds indicated the connecting dihedral angle between both ends of the helix affects the strain in the cyclic scaffold. The experimental collision cross section obtained from IMS-MS favors a propeller model for the helix arrangements. The results not only contribute conformational insights for the polyproline tri-helix system, but also provide precious information for the future design and synthesis of cyclic nanostructures based on peptide helices.

Transforaminal Resection of Cervical Dumbbell Schwannomas in Patients with Additional Tumors.

BACKGROUND: It is rare for 2 primary tumors to occur simultaneously in a patient. Management of cervical dumbbell schwannomas (CDSs) with concurrent tumors (CTs) requires a specific neurosurgical strategy. The primary objective of this study is to investigate surgical strategies for CDSs with CTs while preserving as much of the mechanically relevant bone structures as possible. METHODS: Twelve patients with concurrent CTs and CDSs were identified from 3 medical centers. Surgical strategies for CDSs were based on accurate preoperative images and subsequent treatment considerations for CTs. All patients received surgical treatment for CDSs and CTs. Clinical features, surgical considerations for a transforaminal approach (TA), and ultimate outcome were studied retrospectively. RESULTS: Gross total resection of CDSs was achieved with endoscopic and microscopic assistance in 9 cases, and subtotal resection was achieved in 3 cases after the head and neck surgeons exposed and removed the extraforaminal anatomy. One patient required an additional hemilaminectomy for the resection of the intraspinal segment. After wound healing, patients were transferred to the appropriate surgical department for surgery on CTs with cervical spine stabilization after a transforaminal approach. CONCLUSIONS: In most patients, the stability of the cervical spine can be preserved with low invasive microsurgical or endoscopic transforaminal resection. CTs could be surgically treated sequentially after microscopic- and endoscopic-assisted resection of CDSs.

Development of amino-pyrimidine inhibitors of c-Jun N-terminal kinase (JNK): kinase profiling guided optimization of a 1,2,3-benzotriazole lead.

A series of amino-pyrimidines was developed based upon an initial kinase cross-screening hit from a CDK2 program. Kinase profiling and structure-based drug design guided the optimization from the initial 1,2,3-benzotriazole hit to a potent and selective JNK inhibitor, compound 24f (JNK1 and 2 IC(50)=16 and 66 nM, respectively), with bioavailability in rats and suitable for further in vivo pharmacological evaluation.

Real-time two-dimensional ultrasound guidance for central venous cannulation: a meta-analysis.

BACKGROUND: Use of ultrasound-guided techniques to facilitate central venous cannulation (CVC) may reduce the risk of misplacement and complications. A meta-analysis was conducted to compare real-time two-dimensional ultrasound (RTUS) guidance technique with anatomical landmark technique for CVC to determine whether RTUS has any advantages. METHODS: Randomized studies comparing outcomes in patients undergoing CVC with either RTUS or landmark technique were retrieved from PubMed, ISI Web of Knowledge, EMBASE, and OVID EBM Reviews from their inception to March 2012. RESULTS: Twenty-six studies involving 4,185 CVC procedures met the inclusion criteria. Compared with landmark technique, patients with RTUS had a pooled relative risk (RR) of 0.18 (95% CI: 0.10-0.32) for cannulation failure, 0.25 (95% CI: 0.15-0.42) for arterial puncture, 0.30 (95% CI: 0.19-0.46) for hematoma, 0.21 (95% CI: 0.06-0.73) for pneumothorax, and 0.10 (95% CI: 0.02-0.54) for hemothorax from random-effects models. However, RTUS did not show a reduction in the risk of cannulation failure (RR = 0.26, 95% CI: 0.03-2.55), arterial puncture (RR = 0.34, 95% CI: 0.05-2.60), hematoma (RR = 0.13, 95% CI: 0.01-2.42), pneumothorax (RR = 0.40, 95% CI: 0.02-9.61), and hemothorax (RR = 0.40, 95% CI: 0.02-9.61) in children or infants when the limited data were analyzed. CONCLUSIONS: Among adults receiving CVC, RTUS was associated with decreased risks of cannulation failure, arterial puncture, hematoma, and hemothorax. Additional data of randomized studies are necessary to evaluate these outcomes in pediatric patients.

Non-nucleoside inhibitors of HCV polymerase NS5B. Part 3: synthesis and optimization studies of benzothiazine-substituted tetramic acids.

Benzothiazine-substituted tetramic acids were discovered as highly potent non-nucleoside inhibitors of HCV NS5B polymerase. X-ray crystallography studies confirmed the binding mode of these inhibitors with HCV NS5B polymerase. Rational optimization of time dependent inactivation of CYP 3A4 and clearance was accomplished by incorporation of electron-withdrawing groups to the benzothiazine core.

Understanding our drugs and our diseases.

Analysis of mouse genetic models of human disease-associated traits has provided important insight into the pathogenesis of human disease. As one example, analysis of a murine genetic model of osteoporosis demonstrated that genetic variation within the 15-lipoxygenase (Alox15) gene affected peak bone mass, and that treatment with inhibitors of this enzyme improved bone mass and quality in rodent models. However, the method that has been used to analyze mouse genetic models is very time consuming, inefficient, and costly. To overcome these limitations, a computational method for analysis of mouse genetic models was developed that markedly accelerates the pace of genetic discovery. It was used to identify a genetic factor affecting the rate of metabolism of warfarin, an anticoagulant that is commonly used to treat clotting disorders. Computational analysis of a murine genetic model of narcotic drug withdrawal suggested a potential new approach for treatment of narcotic drug addiction. Thus, the results derived from computational mouse genetic analysis can suggest new treatment strategies, and can provide new information about currently available medicines.

In silico pharmacogenetics of warfarin metabolism.

Pharmacogenetic approaches can be instrumental for predicting individual differences in response to a therapeutic intervention. Here we used a recently developed murine haplotype-based computational method to identify a genetic factor regulating the metabolism of warfarin, a commonly prescribed anticoagulant with a narrow therapeutic index and a large variation in individual dosing. After quantification of warfarin and nine of its metabolites in plasma from 13 inbred mouse strains, we correlated strain-specific differences in 7-hydroxywarfarin accumulation with genetic variation within a chromosomal region encoding cytochrome P450 2C (Cyp2c) enzymes. This computational prediction was experimentally confirmed by showing that the rate-limiting step in biotransformation of warfarin to its 7-hydroxylated metabolite was inhibited by tolbutamide, a Cyp2c isoform-specific substrate, and that this transformation was mediated by expressed recombinant Cyp2c29. We show that genetic variants responsible for interindividual pharmacokinetic differences in drug metabolism can be identified by computational genetic analysis in mice.