On the Role of the Difference in Surface Tensions Involved in the Allosteric Regulation of NHE-1 Induced by Low to Mild Osmotic Pressure, Membrane Tension and Lipid Asymmetry

The sodium-proton exchanger 1 (NHE-1) is a membrane transporter that exchanges Na+ for H+ ion across the membrane of eukaryotic cells. It is cooperatively activated by intracellular protons, and this allosteric regulation is modulated by the biophysical properties of the plasma membrane and related lipid environment. Consequently, NHE-1 is a mechanosensitive transporter that responds to osmotic pressure, and changes in membrane composition. The purpose of this study was to develop the relationship between membrane surface tension, and the allosteric balance of a mechanosensitive transporter such as NHE-1. In eukaryotes, the asymmetric composition of membrane leaflets results in a difference in surface tensions that is involved in the creation of a reservoir of intracellular vesicles and membrane buds contributing to buffer mechanical constraints. Therefore, we took this phenomenon into account in this study and developed a set of relations between the mean surface tension, membrane asymmetry, fluid phase endocytosis and the allosteric equilibrium constant of the transporter. We then used the experimental data published on the effects of osmotic pressure and membrane modification on the NHE-1 allosteric constant to fit these equations. We show here that NHE-1 mechanosensitivity is more based on its high sensitivity towards the asymmetry between the bilayer leaflets compared to mean global membrane tension. This compliance to membrane asymmetry is physiologically relevant as with their slower transport rates than ion channels, transporters cannot respond as high pressure-high conductance fast-gating emergency valves

Roadmap on printable electronic materials for next-generation sensors

The dissemination of sensors is key to realizing a sustainable, ‘intelligent’ world, where everyday objects and environments are equipped with sensing capabilities to advance the sustainability and quality of our lives—e.g., via smart homes, smart cities, smart healthcare, smart logistics, Industry 4.0, and precision agriculture. The realization of the full potential of these applications critically depends on the availability of easy-to-make, low-cost sensor technologies. Sensors based on printable electronic materials offer the ideal platform: they can be fabricated through simple methods (e.g., printing and coating) and are compatible with high-throughput roll-to-roll processing. Moreover, printable electronic materials often allow the fabrication of sensors on flexible/stretchable/biodegradable substrates, thereby enabling the deployment of sensors in unconventional settings. Fulfilling the promise of printable electronic materials for sensing will require materials and device innovations to enhance their ability to transduce external stimuli—light, ionizing radiation, pressure, strain, force, temperature, gas, vapours, humidity, and other chemical and biological analytes. This Roadmap brings together the viewpoints of experts in various printable sensing materials—and devices thereof—to provide insights into the status and outlook of the field. Alongside recent materials and device innovations, the roadmap discusses the key outstanding challenges pertaining to each printable sensing technology. Finally, the Roadmap points to promising directions to overcome these challenges and thus enable ubiquitous sensing for a sustainable, ‘intelligent’ world

Les néphropathies induites par les produits de contraste et la mortalité dans les infarctus du myocarde traités par angioplastie primaire (utilité d une nouvelle définition)

PARIS7-Xavier Bichat (751182101) / SudocSudocFranceF

Caractéristiques et suivi clinique d'une cohorte de patients atteints de myopéricardite confirmée en imagerie par résonance magnétique

Introduction Pericarditis are frequently associated with some degree of concomitant myocardial involvement. Predominant pericarditis with limited myocardial involvement are named myopericarditis. Data regarding myopericarditis are scarce. Patients and methods Retrospective chart review of all patients admitted between 2002 and 2011 with magnetic resonance imaging confirmed myopericarditis. Results Twenty-seven patients were included. Eighty-one percent were men, with median age of 32 years. Infectious disease preceded hospitalization in 55% of cases. Mean left ventricle ejection fraction at admission was 55% with focal myocardial impairment mainly localized in lateral and inferior walls. Coronary angiogram was performed in 37% of cases to rule out an ischaemic aetiology. We identified 5 cases (19%) of myopericarditis preceded by an episode of streptococcus group A throat infection. Non-sustained ventricular tachycardia was observed in 15% of cases. After a 2-year follow-up period, mortality rate was zero and recurrence rate was 15%. Conclusions In our series, myopericarditis was a benign disease affecting mostly young men, and prognosis was good. A significant proportion of cases was preceded by group A streptococcus infection.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Myocardial Fractional Flow Reserve Measurement Using Contrast Media as a First-Line Assessment of Coronary Lesions in Current Practice

International audienceBackground: Fractional flow reserve (FFR) measurement requires adenosine injection. However, adenosine can induce conductive and rhythmic complications, or be contraindicated in some patients. Contrast-induced hyperemia could provide a simple first-line method (contrast-enhanced FFR; cFFR) to assess coronary lesions. In this study we evaluated the accuracy of cFFR to predict lesion significance. Methods: This prospective study included 104 patients with 138 coronary lesions. Each stenosis was evaluated using resting distal coronary pressure to aortic pressure ratio (Pd/Pa) measurements using intracoronary iodixanol (cFFR) and adenosine (FFR) injection. An FFR value <= 0.8 defined a significant lesion. Results: Dose-ranging analysis (n = 12 lesions) showed that 10 mL iodixanol was required to obtain the lowest cFFR value. Inter-measurement reproducibility of cFFR (n = 18 lesions) showed limited variability and small mean estimated bias (0.001 +/- 0.014). Values of cFFR and FFR were highly correlated in a first series of n = 36 lesions (r = 0.9; P < 0.001). Receiver-operating characteristic curve analysis showed an excellent accuracy of cFFR cutoff value of <= 0.85 in predicting FFR value <= 0.80 (area under the curve, 0.94; 95% confidence interval, 0.90-0.98; sensitivity, 95%; specificity, 73%). This threshold was then tested prospectively in an independent cohort of n = 72 lesions. A cFFR value <= 0.85 correctly identified hemodynamically significant lesions with a sensitivity of 100%, specificity of 78%, positive predictive value of 78%, and negative predictive value of 100%. Conclusions: cFFR is reproducible and can be achieved with usual volumes of contrast. A cFFR threshold value of 0.85 provides excellent sensitivity and negative predictive value in coronary artery stenosis

TourExplain: A Crowdsourcing Pipeline for Generating Explanations for Groups of Tourists

When a group is traveling together it is challenging to recommendan itinerary consisting of several points of interest (POIs). Thepreferences of individual group members often diverge, but it isimportant to keep everyone in the group satisfied during the entiretrip. We propose a method to consider the preferences of all thepeople in the group. Building on this method, we design expla-nations for groups of people, to help them reach a consensus forplaces to visit. However, one open question is how to best formu-late explanations for such sequences. In this paper, we introduceTourExplain, an automated crowdsourcing pipeline to generate andevaluate explanations for groups with the aim of improving ourinitial proposed explanations by relying on the wisdom of crowds.Accepted author manuscriptWeb Information System

Evaluation of neutrophil gelatinase-associated lipocalin and cystatin C as biomarkers of acute kidney injury after ST-segment elevation myocardial infarction treated by percutaneous coronary intervention

International audienceBACKGROUND:Two biomarkers of early acute kidney injury-plasmatic neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C-are not used in routine clinical practice in patients with ST-segment elevation myocardial infarction (STEMI) treated by percutaneous coronary intervention (PCI) because of a lack of supporting data.AIMS:To evaluate the predictive value of NGAL and cystatin C regarding the incidence of contrast-induced acute kidney injury (CI-AKI) and clinical outcomes after STEMI in patients treated by primary PCI.METHODS:Plasmatic NGAL and cystatin C were measured on admission, before any contrast exposure, in 701 unselected patients with STEMI. Associations between biomarker concentrations and incidence of CI-AKI (assessed at 48h), haemodialysis requirement at 1 year and all-cause mortality at 1 year were assessed by logistic regression analyses and receiver operating characteristic area under the curve analysis (c-statistic). Discrimination performance comparison was performed using the DeLong test.RESULTS:NGAL and cystatin C had mild discrimination regarding CI-AKI, with c-statistics of 0.60 (P=0.001) and 0.60 (P=0.002), respectively. Combining NGAL and cystatin C did not improve their discrimination (c-statistic 0.61; P=0.001). There was no significant difference in discrimination between NGAL, cystatin C and baseline creatinine (P=0.57). Regression analyses showed no independent association between NGAL and CI-AKI, haemodialysis or 1-year mortality. Similarly, cystatin C was not associated with these clinical outcomes.CONCLUSIONS:In this cohort of patients with STEMI treated by primary PCI, plasmatic NGAL and cystatin C did not provide additional value regarding CI-AKI prediction compared with known risk factors such as baseline creatinine

TourExplain: A Crowdsourcing Pipeline for Generating Explanations for Groups of Tourists

When a group is traveling together it is challenging to recommendan itinerary consisting of several points of interest (POIs). Thepreferences of individual group members often diverge, but it isimportant to keep everyone in the group satisfied during the entiretrip. We propose a method to consider the preferences of all thepeople in the group. Building on this method, we design expla-nations for groups of people, to help them reach a consensus forplaces to visit. However, one open question is how to best formu-late explanations for such sequences. In this paper, we introduceTourExplain, an automated crowdsourcing pipeline to generate andevaluate explanations for groups with the aim of improving ourinitial proposed explanations by relying on the wisdom of crowds