Transcriptional activation of the Axl and PDGFR-α by c-Met through a ras- and Src-independent mechanism in human bladder cancer

<p>Abstract</p> <p>Background</p> <p>A cross-talk between different receptor tyrosine kinases (RTKs) plays an important role in the pathogenesis of human cancers.</p> <p>Methods</p> <p>Both NIH-Met5 and T24-Met3 cell lines harboring an inducible human c-Met gene were established. C-Met-related RTKs were screened by RTK microarray analysis. The cross-talk of RTKs was demonstrated by Western blotting and confirmed by small interfering RNA (siRNA) silencing, followed by elucidation of the underlying mechanism. The impact of this cross-talk on biological function was demonstrated by Trans-well migration assay. Finally, the potential clinical importance was examined in a cohort of 65 cases of locally advanced and metastatic bladder cancer patients.</p> <p>Results</p> <p>A positive association of Axl or platelet-derived growth factor receptor-alpha (PDGFR-α) with c-Met expression was demonstrated at translational level, and confirmed by specific siRNA knock-down. The transactivation of c-Met on Axl or PDGFR-α <it>in vitro </it>was through a <it>ras</it>- and Src-independent activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) pathway. In human bladder cancer, co-expression of these RTKs was associated with poor patient survival (<it>p </it>< 0.05), and overexpression of c-Met/Axl/PDGFR-α or c-Met alone showed the most significant correlation with poor survival (<it>p </it>< 0.01).</p> <p>Conclusions</p> <p>In addition to c-Met, the cross-talk with Axl and/or PDGFR-α also contributes to the progression of human bladder cancer. Evaluation of Axl and PDGFR-α expression status may identify a subset of c-Met-positive bladder cancer patients who may require co-targeting therapy.</p

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Nitric oxide maintains cell survival of Trichomonas vaginalis upon iron depletion

Abstract Background Iron plays a pivotal role in the pathogenesis of Trichomonas vaginalis, the causative agent of highly prevalent human trichomoniasis. T. vaginalis resides in the vaginal region, where the iron concentration is constantly changing. Hence, T. vaginalis must adapt to variations in iron availability to establish and maintain an infection. The free radical signaling molecules reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been proven to participate in iron deficiency in eukaryotes. However, little is known about the roles of these molecules in iron-deficient T. vaginalis. Methods T. vaginalis cultured in iron-rich and -deficient conditions were collected for all experiments in this study. Next generation RNA sequencing was conducted to investigate the impact of iron on transcriptome of T. vaginalis. The cell viabilities were monitored after the trophozoites treated with the inhibitors of nitric oxide (NO) synthase (L-NG-monomethyl arginine, L-NMMA) and proteasome (MG132). Hydrogenosomal membrane potential was measured using JC-1 staining. Results We demonstrated that NO rather than ROS accumulates in iron-deficient T. vaginalis. The level of NO was blocked by MG132 and L-NMMA, indicating that NO production is through a proteasome and arginine dependent pathway. We found that the inhibition of proteasome activity shortened the survival of iron-deficient cells compared with untreated iron-deficient cells. Surprisingly, the addition of arginine restored both NO level and the survival of proteasome-inhibited cells, suggesting that proteasome-derived NO is crucial for cell survival under iron-limited conditions. Additionally, NO maintains the hydrogenosomal membrane potential, a determinant for cell survival, emphasizing the cytoprotective effect of NO on iron-deficient T. vaginalis. Collectively, we determined that NO produced by the proteasome prolonged the survival of iron-deficient T. vaginalis via maintenance of the hydrogenosomal functions. Conclusion The findings in this study provide a novel role of NO in adaptation to iron-deficient stress in T. vaginalis and shed light on a potential therapeutic strategy for trichomoniasis

Urine output as one of the most important features in differentiating in-hospital death among patients receiving extracorporeal membrane oxygenation: a random forest approach

Abstract Background It is common to support cardiovascular function in critically ill patients with extracorporeal membrane oxygenation (ECMO). The purpose of this study was to identify patients receiving ECMO with a considerable risk of dying in hospital using machine learning algorithms. Methods A total of 1342 adult patients on ECMO support were randomly assigned to the training and test groups. The discriminatory power (DP) for predicting in-hospital mortality was tested using both random forest (RF) and logistic regression (LR) algorithms. Results Urine output on the first day of ECMO implantation was found to be one of the most predictive features that were related to in-hospital death in both RF and LR models. For those with oliguria, the hazard ratio for 1 year mortality was 1.445 (p < 0.001, 95% CI 1.265–1.650). Conclusions Oliguria within the first 24 h was deemed especially significant in differentiating in-hospital death and 1 year mortality

Ultra-low-field MRI and its combination with MEG

| openaire: EC/H2020/686865/EU//BREAKBENRecent progress in SQUID instrumentation has demonstrated the feasibility of using SQUID sensor arrays in MEG helmets to record also MRI data. Here we describe the basic principles of MRI as well as the special requirements and solutions needed to perform ultra-low-field MRI concurrently with MEG. We consider it is feasible to build practical MEG-MRI instruments for scientific experimentation and for clinical use. Acquiring an MRI with 2-mm spatial resolution and sufficient signal-to-noise ratio and contrast appears achievable without essentially lengthening the normal MEG measurement time.Peer reviewe