The Cytotoxic Necrotizing Factor of Yersinia pseudotuberculosis (CNFy) is Carried on Extracellular Membrane Vesicles to Host Cells

In this study we show Yersinia pseudotuberculosis secretes membrane vesicles (MVs) that contain different proteins and virulence factors depending on the strain. Although MVs from Y. pseudotuberculosis YPIII and ATCC 29833 had many proteins in common (68.8% of all the proteins identified), those located in the outer membrane fraction differed significantly. For instance, the MVs from Y. pseudotuberculosis YPIII harbored numerous Yersinia outer proteins (Yops) while they were absent in the ATCC 29833 MVs. Another virulence factor found solely in the YPIII MVs was the cytotoxic necrotizing factor (CNFy), a toxin that leads to multinucleation of host cells. The ability of YPIII MVs to transport this toxin and its activity to host cells was verified using HeLa cells, which responded in a dose-dependent manner; nearly 70% of the culture was multinucleated after addition of 5 mu g/ml of the purified YPIII MVs. In contrast, less than 10% were multinucleated when the ATCC 29833 MVs were added. Semi-quantification of CNFy within the YPIII MVs found this toxin is present at concentrations of 5 -10 ng per mu g of total MV protein, a concentration that accounts for the cellular responses see

Conditionally reprogrammed primary airway epithelial cells maintain morphology, lineage and disease specific functional characteristics

© 2017 The Author(s). Current limitations to primary cell expansion led us to test whether airway epithelial cells derived from healthy children and those with asthma and cystic fibrosis (CF), co-cultured with an irradiated fibroblast feeder cell in F-medium containing 10 µM ROCK inhibitor could maintain their lineage during expansion and whether this is influenced by underlying disease status. Here, we show that conditionally reprogrammed airway epithelial cells (CRAECs) can be established from both healthy and diseased phenotypes. CRAECs can be expanded, cryopreserved and maintain phenotypes over at least 5 passages. Population doublings of CRAEC cultures were significantly greater than standard cultures, but maintained their lineage characteristics. CRAECs from all phenotypes were also capable of fully differentiating at air-liquid interface (ALI) and maintained disease specific characteristics including; defective CFTR channel function cultures and the inability to repair wounds. Our findings indicate that CRAECs derived from children maintain lineage, phenotypic and importantly disease-specific functional characteristics over a specified passage range

Molecular dynamics simulations of non-equilibrium systems

Peer reviewe

Clinical predictors of transvenous defibrillation energy requirements.

Nonthoracotomy and, more recently, transvenous lead systems have become routine for initial implantable cardioverter-defibrillator (ICD) placement. Previous studies of clinical predictors of nonthoracotomy defibrillation energy requirements evaluated multiple complex lead systems that included subcutaneous patches. However, the predictors of an adequate transvenous defibrillation threshold (DFT) have not been assessed previously. Accordingly, the present study is a prospective evaluation of DFT using a uniform testing protocol in 119 consecutive patients undergoing ICD implantation with a single transvenous lead. For each patient, 38 parameters were assessed including standard clinical, echocardiographic, and radiographic measures. An adequate monophasic DFT (\u3c or =20 J) was achieved in 76% of patients. Multivariable analysis revealed 3 independent factors predictive of a high threshold: preoperative amiodarone use (odds ratio = 5.8, p \u3c or =0.002), echocardiographic measures of left ventricular dilation (odds ratio = 0.47, p \u3c or =0.005) and body size (odds ratio = 0.51, p \u3c or =0.006). Patients receiving amiodarone who also had left ventricular dilation constitute a group at considerable (69%) risk for having a high DFT. In contrast, patients with neither of these risk factors have only an 11% chance of having a high threshold. We conclude that an adequate transvenous DFT can be predicted from simple clinical parameters