Mechanisms of ranolazine's dual protection against atrial and ventricular fibrillation

Coronary artery disease and heart failure carry concurrent risk for atrial fibrillation and life-threatening ventricular arrhythmias. We review evidence indicating that at therapeutic concentrations, ranolazine has potential for dual suppression of these arrhythmias. Mechanisms and clinical implications are discussed

Improvement of the size estimation of 3D tracked droplets using digital in-line holography with joint estimation reconstruction

International audienceDigital holography is a valuable tool for three-dimensional information extraction. Among existing configurations, the originally proposed setup (i.e. Gabor, or in-line holography), is reasonably immune to variations in the experimental environment making it a method of choice for studies of fluid dynamics. Nevertheless, standard hologram reconstruction techniques, based on numerical light back-propagation are prone to artifacts such as twin images or aliases that limit both the quality and quantity of information extracted from the acquired holograms. To get round this issue, the hologram reconstruction as a parametric inverse problem has been shown to accurately estimate 3D positions and the size of seeding particles directly from the hologram. To push the bounds of accuracy on size estimation still further, we propose to fully exploit the information redundancy of a hologram video sequence using joint estimation reconstruction. Applying this approach in a bench-top experiment, we show that it led to a relative accuracy of 0.13 % (for a 30 µm diameter droplet) for droplet size estimation, and a tracking accuracy of σ x × σ y × σ z = 0.15 × 0.15 × 1 pixels

Association of Air Pollution with Increased Incidence of Ventricular Tachyarrhythmias Recorded by Implanted Cardioverter Defibrillators

Epidemiologic studies have demonstrated a consistent link between sudden cardiac deaths and particulate air pollution. We used implanted cardioverter defibrillator (ICD) records of ventricular tachyarrhythmias to assess the role of air pollution as a trigger of these potentially life-threatening events. The study cohort consisted of 203 cardiac patients with ICD devices in the Boston metropolitan area who were followed for an average of 3.1 years between 1995 and 2002. Fine particle mass and gaseous air pollution plus temperature and relative humidity were measured on almost all days, and black carbon, sulfate, and particle number on a subset of days. Date, time, and intracardiac electrograms of ICD-detected arrhythmias were downloaded at the patients’ regular follow-up visits (about every 3 months). Ventricular tachyarrhythmias were identified by electrophysiologist review. Risk of ventricular arrhythmias associated with air pollution was estimated with logistic regression, adjusting for season, temperature, relative humidity, day of the week, patient, and a recent prior arrhythmia. We found increased risks of ventricular arrhythmias associated with 2-day mean exposure for all air pollutants considered, although these associations were not statistically significant. We found statistically significant associations between air pollution and ventricular arrhythmias for episodes within 3 days of a previous arrhythmia. The associations of ventricular tachyarrhythmias with fine particle mass, carbon monoxide, nitrogen dioxide, and black carbon suggest a link with motor vehicle pollutants. The associations with sulfate suggest a link with stationary fossil fuel combustion sources

Assessment of semantic memory with the SMT-42

International audienc

Apport du test de mémoire sémantique 42 items (TMS-42) en consultation mémoire

International audienc

Some Secrets of Fluorescent Proteins: Distinct Bleaching in Various Mounting Fluids and Photoactivation of cyan fluorescent proteins at YFP-Excitation

Background
The use of spectrally distinct variants of green fluorescent protein (GFP) such as cyan or yellow mutants (CFP and YFP, respectively) is very common in all different fields of life sciences, e.g. for marking specific proteins or cells or to determine protein interactions. In the latter case, the quantum physical phenomenon of fluorescence resonance energy transfer (FRET) is exploited by specific microscopy techniques to visualize proximity of proteins.

Methodology/Principal Findings
When we applied a commonly used FRET microscopy technique - the increase in donor (CFP)-fluorescence after bleaching of acceptor fluorophores (YFP), we obtained good signals in live cells, but very weak signals for the same samples after fixation and mounting in commercial microscopy mounting fluids. This observation could be traced back to much faster bleaching of CFP in these mounting media. Strikingly, the opposite effect of the mounting fluid was observed for YFP and also for other proteins such as Cerulean, TFP or Venus. The changes in photostability of CFP and YFP were not caused by the fixation but directly dependent on the mounting fluid. Furthermore we made the interesting observation that the CFP-fluorescence intensity increases by about 10 - 15% after illumination at the YFP-excitation wavelength – a phenomenon, which was also observed for Cerulean. This photoactivation of cyan fluorescent proteins at the YFP-excitation can cause false-positive signals in the FRET-microscopy technique that is based on bleaching of a yellow FRET acceptor.

Conclusions/Significance
Our results show that photostability of fluorescent proteins differs significantly for various media and that CFP bleaches significantly faster in commercial mounting fluids, while the opposite is observed for YFP and some other proteins. Moreover, we show that the FRET microscopy technique that is based on bleaching of the YFP is prone to artifacts due to photoactivation of cyan fluorescent proteins under these conditions

Continuous-mode 448 kHz capacitive resistive monopolar radiofrequency induces greater deep blood flow changes compared to pulsed mode shortwave: a crossover study in healthy adults

This document is the Accepted Manuscript version of the following article: Binoy Kumaran, Anthony Herbland and Tim Watson, ‘Continuous-mode 448 kHz capacitive resistive monopolar radiofrequency induces greater deep blood flow changes compared to pulsed mode shortwave: a crossover study in healthy adults’, European Journal of Physiotheraphy, first published online 20 April 2017. The version of record is available online at doi: http://dx.doi.org/10.1080/21679169.2017.1316310. © 2017 Informa UK Limited, trading as Taylor & Francis Group.Aims: Radiofrequency-based electrophysical agents (EPAs) have been used in therapy practice over several decades (e.g. shortwave therapies). Currently, there is insufficient evidence supporting such EPAs operating below shortwave frequencies. This laboratory-based study investigated the deep physiological effects of 448 kHz capacitive resistive monopolar radiofrequency (CRMRF) and compared them to pulsed shortwave therapy (PSWT). Methods: In a randomized crossover study, 17 healthy volunteers initially received four treatment conditions: high, low and placebo dose conditions receiving 15-min CRMRF treatment and a control condition receiving no intervention. Fifteen participants additionally received high-dose PSWT as fifth condition, for comparison. Pre- and post-treatment measurements of deep blood flow and tissue extensibility were obtained using Doppler ultrasound and sonoelastography. Group data were compared using analysis of variance model. Statistical significance was set at p ≤ .05, 0.8 power, and 95% confidence interval. Results: Significant increases in volume and intensity of deep blood flow were obtained with CRMRF over placebo, control (p = .003) and PSWT (p < .001). No significant changes in blood flow velocity or tissue extensibility were noted for any condition. Conclusions: Deep blood flow changes with CRMRF were more pronounced than that with PSWT, placebo or control. Potential greater therapeutic benefits need to be confirmed with comparative clinical studies.Peer reviewe