790 research outputs found

    On existence and multiplicity for Schrödinger–Poisson systems involving weighted sublinear nonlinearities

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    We deal with existence and multiplicity for the following class of nonhomogeneous Schrödinger–Poisson systems \begin{equation*} \begin{cases} -\Delta u + V(x) u + K(x) \phi(x) u = f(x, u) + g(x) \quad & \text{in } \mathbb{R}^3, \\ -\Delta \phi = K(x) u^2 \quad & \text{in } \mathbb{R}^3, \end{cases} \end{equation*} where V,K:R3R+V, K: \mathbb{R}^3 \rightarrow \mathbb{R}^+ are suitable potentials and f:R3×RRf: \mathbb{R}^3 \times \mathbb{R} \rightarrow \mathbb{R} satisfies sublinear growth assumptions involving a finite number of positive weights WiW_i, i=1,,ri= 1,\dots,r with r1r \geq 1. By exploiting compact embeddings of the functional space on which we work in every weighted space LWiwi(R3)L_{W_i}^{w_i}(\mathbb{R}^3), wi(1,2)w_i \in (1, 2), we establish existence by means of a generalized Weierstrass theorem. Moreover, we prove multiplicity of solutions if ff is odd in uu and g(x)0g(x) \equiv 0 thanks to a variant of the symmetric mountain pass theorem stated by R. Kajikiya for subquadratic functionals

    Flow cytometric analysis of extracellular vesicles from cell-conditioned media

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    Flow cytometry (FC) is the method of choice for semi-quantitative measurement of cell-surface antigen markers. Recently, this technique has been used for phenotypic analyses of extracellular vesicles (EV) including exosomes (Exo) in the peripheral blood and other body fluids. The small size of EV mandates the use of dedicated instruments having a detection threshold around 50-100 nm. Alternatively, EV can be bound to latex microbeads that can be detected by FC. Microbeads, conjugated with antibodies that recognize EV-associated markers/Cluster of Differentiation CD63, CD9, and CD81 can be used for EV capture. Exo isolated from CM can be analyzed with or without pre-enrichment by ultracentrifugation. This approach is suitable for EV analyses using conventional FC instruments. Our results demonstrate a linear correlation between Mean Fluorescence Intensity (MFI) values and EV concentration. Disrupting EV through sonication dramatically decreased MFI, indicating that the method does not detect membrane debris. We report an accurate and reliable method for the analysis of EV surface antigens, which can be easily implemented in any laboratory

    Identification of a serum and urine extracellular vesicle signature predicting renal outcome after kidney transplant

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    Background A long-standing effort is dedicated towards the identification of biomarkers allowing the prediction of graft outcome after kidney transplant. Extracellular vesicles (EVs) circulating in body fluids represent an attractive candidate, as their cargo mirrors the originating cell and its pathophysiological status. The aim of the study was to investigate EV surface antigens as potential predictors of renal outcome after kidney transplant. Methods We characterized 37 surface antigens by flow cytometry, in serum and urine EVs from 58 patients who were evaluated before, and at 10-14 days, 3 months and 1 year after transplant, for a total of 426 analyzed samples. The outcome was defined according to estimated glomerular filtration rate (eGFR) at 1 year. Results Endothelial cells and platelets markers (CD31, CD41b, CD42a and CD62P) in serum EVs were higher at baseline in patients with persistent kidney dysfunction at 1 year, and progressively decreased after kidney transplant. Conversely, mesenchymal progenitor cell marker (CD1c, CD105, CD133, SSEEA-4) in urine EVs progressively increased after transplant in patients displaying renal recovery at follow-up. These markers correlated with eGFR, creatinine and proteinuria, associated with patient outcome at univariate analysis and were able to predict patient outcome at receiver operating characteristics curves analysis. A specific EV molecular signature obtained by supervised learning correctly classified patients according to 1-year renal outcome. Conclusions An EV-based signature, reflecting the cardiovascular profile of the recipient, and the repairing/regenerative features of the graft, could be introduced as a non-invasive tool for a tailored management of follow-up of patients undergoing kidney transplant

    A dynamic clamping approach using in silico IK1 current for discrimination of chamber-specific hiPSC-derived cardiomyocytes

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    : Human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (CM) constitute a mixed population of ventricular-, atrial-, nodal-like cells, limiting the reliability for studying chamber-specific disease mechanisms. Previous studies characterised CM phenotype based on action potential (AP) morphology, but the classification criteria were still undefined. Our aim was to use in silico models to develop an automated approach for discriminating the electrophysiological differences between hiPSC-CM. We propose the dynamic clamp (DC) technique with the injection of a specific IK1 current as a tool for deriving nine electrical biomarkers and blindly classifying differentiated CM. An unsupervised learning algorithm was applied to discriminate CM phenotypes and principal component analysis was used to visualise cell clustering. Pharmacological validation was performed by specific ion channel blocker and receptor agonist. The proposed approach improves the translational relevance of the hiPSC-CM model for studying mechanisms underlying inherited or acquired atrial arrhythmias in human CM, and for screening anti-arrhythmic agents

    Lower pneumonia risk in COPD patients initiating fixed dose combination (FDC) inhaler comprising extrafine beclometasone dipropionate versus fluticasone

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    Grant support: This study was funded by Chiesi Farmaceutici S.p.A. David Price has grants and unrestricted funding for investigator-initiated studies (conducted through Observational and Pragmatic Research Institute Pte Ltd) from AstraZeneca, Boehringer Ingelheim, Chiesi, Mylan, Novartis, Regeneron Pharmaceuticals, Respiratory Effectiveness Group, Sanofi Genzyme, Theravance and UK National Health Service; is a peer reviewer for grant committees of the UK Efficacy and Mechanism Evaluation programme, and Health Technology Assessment; and was an expert witness for GlaxoSmithKline.Peer reviewe

    Statins reduce intratumor cholesterol affecting adrenocortical cancer growth

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    Mitotane causes hypercholesterolemia in ACC patients. We suppose that cholesterol increases within the tumor and can be used to activate proliferative pathways. In this study, we used statins to decrease intratumor cholesterol and investigated the effects on ACC growth related to ER\u3b1 action at the nuclear and mitochondrial levels. We first used microarray to investigate mitotane effect on genes involved in cholesterol homeostasis and evaluated their relationship with patients' survival in ACC TCGA. We then blocked cholesterol synthesis with simvastatin and determined the effects on H295R cell proliferation, estradiol production and ER\u3b1 activity in vitro and in xenograft tumors. We found that mitotane increases intratumor cholesterol content and expression of genes involved in cholesterol homeostasis, among them INSIG, whose expression affects patients' survival. Treatment of H295R cells with simvastatin to block cholesterol synthesis decreased cellular cholesterol content and this affected cell viability. Simvastatin reduced estradiol production and decreased nuclear and mitochondrial ER\u3b1 function. A mitochondrial target of ER\u3b1, the respiratory complex IV (COX IV) was reduced after simvastatin treatment, which profoundly affected mitochondrial respiration activating apoptosis. In vivo experiments confirmed the ability of simvastatin to reduce tumor volume and weight of grafted H295R cells, intratumor cholesterol content, Ki-67 and ER\u3b1, COX IV expression and activity and increase TUNEL positive cells. Collectively these data demonstrate that a reduction in intratumor cholesterol content prevents estradiol production, inhibits mitochondrial respiratory chain inducing apoptosis in ACC cells. Inhibition of mitochondrial respiration by simvastatin represents a novel strategy to counteract ACC growth
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