Search results for "Fibril"

Intravenous BQ-123 and phosphoramidon reduce ventricular ectopic beats and myocardial infarct size in dogs submitted to coronary occlusion and reperf…

2001

Abstract The aim of this work was to investigate the influence of endothelin on myocardial ischemia and reperfusion in anaesthetized dogs. Animals were submitted to left thoracotomy and 120 min of left anterior descending coronary occlusion, followed by 180 min of reperfusion. Arterial blood pressure and electrocardiogram (ECG) were recorded in order to analyze heart rate (HR)–pressure product and production of ectopic beats. Infarcted areas were identified by a macroscopic staining method and infarct size was expressed as percentage of risk zone. To inhibit the effects of endothelin in a group of animals, we administered intravenously an endothelin synthesis inhibitor (phosphoramidon) and …

Protecting against sedentary lifestyle, left atrial enlargement and atrial fibrillation.

2022

NG2 and GFAP co-expression after differentiation in cells transfected with mutant GFAP and in undifferentiated glioma cells

2020

Introduction: Alexander disease is a rare disorder caused by mutations in the gene coding for glial fibrillary acidic protein (GFAP). In a previous study, differentiation of neurospheres transfected with these mutations resulted in a cell type that expresses both GFAP and NG2. Objective: To determine the effect of molecular marker mutations in comparison to undifferentiated glioma cells simultaneously expressing GFAP and NG2. Methods: We used samples of human glioblastoma (GBM) and rat neurospheres transfected with GFAP mutations to analyse GFAP and NG2 expression after differentiation. We also performed an immunocytochemical analysis of neuronal differentiation for both cell types and dete…

Conical nanopores highlight the pro-aggregating effects of pyrimethanil fungicide on Aβ(1-42) peptides and dimeric splitting phenomena.

2022

International audience; The Aβ(1-42) aggregation is a key event in the physiopathology of Alzheimer's disease (AD). Exogenous factors such as environmental pollutants, and more particularly pesticides, can corrupt Aβ(1-42) assembly and could influence the occurrence and pathophysiology of AD. However, pesticide involvement in the early stages of Aβ(1-42) aggregation is still unknown. Here, we employed conical track-etched nanopore in order to analyse the Aβ(1-42) fibril formation in the presence of pyrimethanil, a widely used fungicide belonging to the anilinopyrimidine class. Our results evidenced a pro-aggregating effect of pyrimethanil on Aβ(1-42). Aβ(1-42) assemblies were successfully d…

Biciliated ependymal cell proliferation contributes to spinal cord growth

2012

Two neurogenic regions have been described in the adult brain, the lateral ventricle subventricular zone and the dentate gyrus subgranular zone. It has been suggested that neural stem cells also line the central canal of the adult spinal cord. Using transmission and scanning electron microscopy and immunostaining, we describe here the organization and cell types of the central canal epithelium in adult mice. The identity of dividing cells was determined by 3D ultrastructural reconstructions of [3H]thymidine-labeled cells and confocal analysis of bromodeoxyuridine labeling. The most common cell type lining the central canal had two long motile (9+2) cilia and was vimentin+, CD24+, FoxJ1+, So…

New epicardial mapping electrode with warming/cooling function for experimental electrophysiology studies

2010

Cardiac electrical activity is influenced by temperature. In experimental models, the induction of hypothermia and/or hyperthermia has been used for the study of mechanisms of cardiac arrhythmia. A system that allows for localized, controlled induction, besides simultaneously recording electrical activity in the same induced area, needs to be developed ad hoc. This article describes the construction and application of a new system capable of locally modifying the epicardial temperature of isolated hearts and of carrying out cardiac mapping with sufficient spatial resolution. The system is based on a thermoelectric refrigerator and an array of 128 stainless steel unipolar electrodes in encap…

Erythrocyte aggregation in nonvalvular atrial fibrillation

2001

Characterization of protofibrillar aggregates of bovine serum albumin by tryptophans fluorescence lifetime

2010

We report an experimental study on the thermally induced aggregation of Bovine Serum Albumin at basic pH. In these conditions, we observe the growth of simple protofibrillar structures via the formation of intermolecular beta-sheets promoted by the increased electrostatic repulsion. Here we present a study on the time resolved fluorescence of Tryptophans (Trp) along the aggregation kinetics in the above reported conditions. We use the lifetimes distribution approach as a useful tool for the interpretation of the fluorescence decay in terms of protein conformational substates and interconversion dynamics. Trp fluorescence lifetime depends from protein conformations, also in relation with sol…

Comparación de la efectividad de dos sistemas de monitorización electrocardiográfica ambulatoria, en la detección de recurrencias en pacientes con fi…

2020

Antecedentes: La fibrilación auricular es una de las arritmias cardíacas que más comprometen y afectan a la calidad de vida de las personas que la sufren, incrementando considerablemente su morbimortalidad. La crioablación de las venas pulmonares es una opción terapéutica de elección en pacientes con fibrilación auricular paroxística. El holter electrocardiográfico es una herramienta muy útil en el control de recurrencias, pues posibilita un registro continuo de la actividad eléctrica del corazón. Objetivos: El análisis de los datos pretende comparar la efectividad de ambos métodos e identificar el perfil de pacientes que se beneficia de cada uno de ellos. Metodología: Esta tesis es un estu…

Silent and symptomatic atrial fibrillation,during the acute phase of myocardial infarction : determinants and role of arginine methylated and oxidati…

2015

Atrial fibrillation (AF) is a frequent complication of acute myocardial infarction (AMI) with a poorer prognosis. Silent atrial fibrillation has been suggested to be frequent after AMI. However, most part of the studies has targeted only paroxysmal or persistent AF. Thus, Reduced Nitric Oxide availability and endothelial dysfunction has been recently recognized as a possible contributor to altered prognosis in AF. Asymmetric dimethylarginine (ADMA) can inhibit nitric oxide synthase and leads to endothelial dysfunction, inflammation and oxidative stress in multiple cardiovascular diseases. However, any study has addressed the relationship between ADMA levels and the occurrence of AF in AMI.W…