Putative Inv Is Essential for Basolateral Invasion of Caco-2 Cells and Acts Synergistically with OmpA To Affect In Vitro and In Vivo Virulence of Cronobacter sakazakii ATCC 29544

Cronobacter sakazakii is an opportunistic pathogen that causes neonatal meningitis and necrotizing enterocolitis. Its interaction with intestinal epithelium is important in the pathogenesis of enteric infections. In this study, we investigated the involvement of the inv gene in the virulence of C. sakazakii ATCC 29544 in vitro and in vivo. Sequence analysis of C. sakazakii ATCC 29544 inv revealed that it is different from other C. sakazakii isolates. In various cell culture models, an Δinv deletion mutant showed significantly lowered invasion efficiency, which was restored upon genetic complementation. Studying invasion potentials using tight-junction-disrupted Caco-2 cells suggested that the inv gene product mediates basolateral invasion of C. sakazakii ATCC 29544. In addition, comparison of invasion potentials of double mutant (ΔompA Δinv) and single mutants (ΔompA and Δinv) provided evidence for an additive effect of the two putative outer membrane proteins. Finally, the importance of inv and the additive effect of putative Inv and OmpA were also proven in an in vivo rat pup model. This report is the first to demonstrate two proteins working synergistically in vitro, as well as in vivo in C. sakazakii pathogenesis.     

Effect of ACL graft material on joint forces during a simulated in vivo motion in the porcine knee: Examining force during the initial cycles

This study compared three‐dimensional forces in knees containing anterior cruciate ligament (ACL) graft materials versus the native porcine ACL. A six‐degree‐of‐freedom (DOF) robot simulated gait while recording the joint forces and moments. Knees were subjected to 10 cycles of simulated gait in intact, ACL‐deficient, and ACL‐reconstructed knee states to examine time zero biomechanical performance. Reconstruction was performed using bone‐patellar tendon‐bone allograft (BPTB), reconstructive porcine tissue matrix (RTM), and an RTM‐polymer hybrid (Hybrid). Forces and moments were examined about anatomic DOFs throughout the gait cycle and at three key points during gait: heel strike (HS), mid stance (MS), toe off (TO). Compared to native ACL, each graft restored antero‐posterior (A‐P) forces throughout gait. However, all failed to mimic normal joint forces in other DOFs. For example, each reconstructed knee showed greater compressive forces at HS and TO compared to the native ACL knee. Overall, the Hybrid graft restored more of the native ACL forces following reconstruction than did BPTB, while RTM grafts were the least successful. If early onset osteoarthritis is in part caused by altered knee kinematics, then understanding how reconstruction materials restore critical force generation during gait is an essential step in improving a patient's long‐term prognosis. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1458–1463, 2014.     

Usefulness of Left Ventricular Vortex Flow Analysis for Predicting Clinical Outcomes in Patients with Chronic Heart Failure: A Quantitative Vorticity Imaging Study Using Contrast Echocardiography

The goal of the study described here was to evaluate whether left ventricular vortex flow parameters, as assessed by contrast echocardiography, enhance prediction of major adverse cardiac events (MACE) in patients with chronic heart failure and systolic dysfunction. A total of 75 patients with contrast echocardiography and systolic dysfunction (ejection fraction ≤45%) were prospectively enrolled and underwent vortex flow analysis with particle image velocimetry using contrast echocardiography. Vortex flow parameters, including kinetic energy fluctuation (KEF), were evaluated. Patients were followed up for a primary endpoint of MACE that comprised hospital admission for cardiovascular causes and cardiac deaths. Across a median 277-d follow-up, 29 patients (38.7%) experienced MACE. Among these, the incidence of diabetes and the E/e' ratio were significantly higher in patients with MACE than in those without, whereas the hemoglobin level and ejection fraction were significantly lower. KEF was significantly lower in patients with MACE. In the multivariate analysis, higher KEF was associated with a lower risk of MACE (hazard ratio?=?0.18, 95% confidence interval: 0.04–0.97, p?=?0.046). The addition of KEF to a model with conventional parameters (e.g., age, diabetes, ejection fraction and the E/e' ratio) significantly improved the model's discrimination. Elevations in the quantitative left ventricular vortex flow parameter, KEF, as determined by contrast echocardiography, are associated with a lower risk of MACE and improved functional status among patients with chronic heart failure.     

Cell Death by Polyvinylpyrrolidine-Coated Silver Nanoparticles is Mediated by ROS-Dependent Signaling

Silver nanoparticles (AgNPs) are widely used nanoparticles and they are mainly used in antibacterial and personal care products. In this study, we evaluated the effect of AgNPs on cell death induction in the murine dendritic cell line DC2.4. DC2.4 cells exposed to AgNPs showed a marked decrease in cell viability and an induction of lactate dehydrogenase (LDH) leakage in a time- and dose-dependent manner. In addition, AgNPs promoted reactive oxygen species (ROS)-dependent apoptosis and AgNP-induced ROS triggered a decrease in mitochondrial membrane potential. The activation of the intracellular signal transduction pathway was also observed in cells cultured with AgNPs. Taken together, our data demonstrate that AgNPs are able to induce a cytotoxic effect in DCs through ROS generation. This study provides important information about the safety of AgNPs that may help in guiding the development of nanotechnology applications.     

Sigma metric analysis for performance of creatinine with fresh frozen serum

Background: Six sigma provides an objective and quantitative methodology to describe the laboratory testing performance. In this study, we conducted a national trueness verification scheme with fresh frozen serum (FFS) for serum creatinine to evaluate its performance in China. Methods: Two different concentration levels of FFS, targeted with reference method, were sent to 98 laboratories in China. Imprecision and bias of the measurement procedure were calculated for each participant to further evaluate the sigma value. Quality goal index (QGI) analysis was used to investigate the reason of unacceptable performance for laboratories with σ?Results: Our study indicated that the sample with high concentration of creatinine had preferable sigma values. For the enzymatic method, 7.0% (5/71) to 45.1% (32/71) of the laboratories need to improve their measurement procedures (σ??1.2). Only 3.1–5.3% of the laboratories should improve both of the precision and trueness. Conclusions: Sigma metric analysis of the serum creatinine assays is disappointing, which was mainly due to the unacceptable analytical bias according to the QGI analysis. Further effort is needed to enhance the trueness of the creatinine measurement.     

Welcome back survey: exploring concerns impacting HIV care engagement and retention

The current study describes the development of a short pre-clinic survey that helped multidiscipline providers to elicit patient perspective on barriers to HIV primary care. The survey was piloted with 318 patients returning to care after being lost to care for at least 12 months. Reasons for breaks in care were dependent on age, gender, and race. Concerns about confidentiality in care were more commonly reported by African-American, Latino, and younger patients, while concerns relating to acceptance of diagnosis and side effects were greater for women, African-American, and Latino participants. Further, Intimate Partner Violence (IPV) and transportation were greater concerns for women and younger patients in the sample.