Search results for "myocardium"

Atrial fibrillation is associated with cardiac hypoxia.

2008

BACKGROUND: Atrial fibrillation (AF), the most common human arrhythmia, is responsible for substantial morbidity and mortality and may be promoted by selective atrial ischemia and atrial fibrosis. Consequently, we investigated markers for hypoxia and angiogenesis in AF. METHODS: Right atrial appendages (n=158) were grouped according to heart rhythm [sinus rhythm (SR) or AF]. The degree of fibrosis and microvessel density of all patients were determined morphometrically using Sirius-Red- and CD34/CD105-stained sections, respectively. Next, sections (n=77) underwent immunostaining to detect hypoxia- and angiogenesis-related proteins [hypoxia-inducible factor (HIF)1 alpha, HIF2 alpha, vascular…

Heart and Skeletal Muscles: Linked by Autonomic Nervous System.

2019

Background Resting sympathetic hyperactivity and impaired parasympathetic reactivation after exercise have been described in patients with heart failure (HF). However, the association of these autonomic changes in patients with HF and sarcopenia is unknown. Objective The aim of this study was to evaluate the impact of autonomic modulation on sarcopenia in male patients with HF. Methods We enrolled 116 male patients with HF and left ventricular ejection fraction < 40%. All patients underwent a maximal cardiopulmonary exercise testing. Maximal heart rate was recorded and delta heart rate recovery (∆HRR) was assessed at 1st and 2nd minutes after exercise. Muscle sympathetic nerve activity (MSN…

Heredity and obesity-associated hypertension: impact of hormonal characteristics and left ventricular mass.

1995

Objectives : To investigate the influence of heredity on obesity-associated hypertension, we evaluated casual and 24-h blood pressure, left ventricular mass and some metabolic and hormonal measurements in normotensive obese subjects. Design : Healthy, normotensive obese subjects (n = 81) with positive or negative family history of hypertension were studied. Both groups were also subdivided according to a positive or a negative family history of obesity. Accordingly, 45 obese subjects had a positive family history of hypertension, 25 of these having a positive (subgroup A) and 20 having a negative family history of obesity (subgroup B). The other 36 obese subjects had a negative family histo…

The

2016

ABSTRACT Members of the Junctophilin (JPH) protein family have emerged as key actors in all excitable cells, with crucial implications for human pathophysiology. In mammals, this family consists of four members (JPH1-JPH4) that are differentially expressed throughout excitable cells. The analysis of knockout mice lacking JPH subtypes has demonstrated their essential contribution to physiological functions in skeletal and cardiac muscles and in neurons. Moreover, mutations in the human JPH2 gene are associated with hypertrophic and dilated cardiomyopathies; mutations in JPH3 are responsible for the neurodegenerative Huntington's disease-like-2 (HDL2), whereas JPH1 acts as a genetic modifier …

Kinetics of in vivo inhibition of tissue cathepsin d by pepstatin A

1988

1. 1. We have investigated the kinetics of inhibition of cathepsin D in heart, liver and skeletal muscle of CD-1 mice following administration of 25, 50, 100 and 200 mg/kg i.p. of pepstatin A, a specific inhibitor of this protease. 2. 2. In the liver, a significant inhibition of cathepsin D occurred up to at least 15 days, whereas, in heart and skeletal muscle, this inhibition lasted for a much shorter period of time. 3. 3. These results show that the recovery of enzyme activity to normal values is dose-dependent and that, at the same dose level, marked differences occur in the recovery of enzyme activity in these organ tissues, the liver being the most sensitive one. © 1988.

Automatic estimation of Purkinje-Myocardial junction hot-spots from noisy endocardial samples: A simulation study

2017

The reconstruction of the ventricular cardiac conduction system (CCS) from patient-specific data is a challenging problem. High-resolution imaging techniques have allowed only the segmentation of proximal sections of the CCS from images acquired ex vivo. In this paper, we present an algorithm to estimate the location of a set of Purkinje-myocardial junctions (PMJs) from electro-anatomical maps, as those acquired during radio-frequency ablation procedures. The method requires a mesh representing the myocardium with local activation time measurements on a subset of nodes. We calculate the backwards propagation of the electrical signal from the measurement points to all the points in the mesh …

Texture analysis of cardiac cine magnetic resonance imaging to detect nonviable segments in patients with chronic myocardial infarction.

2017

[EN] Purpose: To investigate the ability of texture analysis to differentiate between infarcted nonviable, viable, and remote segments on cardiac cine magnetic resonance imaging (MRI). Methods: This retrospective study included 50 patients suffering chronic myocardial infarction. The data were randomly split into training (30 patients) and testing (20 patients) sets. The left ventricular myocardium was segmented according to the 17-segment model in both cine and late gadolinium enhancement (LGE) MRI. Infarcted myocardium regions were identified on LGE in short-axis views. Nonviable segments were identified as those showing LGE 50%, and viable segments those showing 0 < LGE < 50% transmural …

Noradrenalin- und Adrenalingehalt des Rattenherzens bei experimenteller Niereninsuffizienz

1960

Virus-receptor interactions of coxsackie B viruses and their putative influence on cardiotropism

2003

Specific virus-receptor interactions are important determinants in the pathogenesis of viral infections, influencing the location and initiation of primary infection as well as the viral spread to other target organs in the postviremic phase. Coxsackieviruses of group B (CVB) specifically interact with at least two receptor proteins, the coxsackievirus-adenovirus receptor (CAR) and the decay-accelerating factor (DAF), and cause a broad spectrum of diseases, including acute and chronic myocarditis. In the human heart, CAR is predominantly expressed in intercalated discs, regions of utmost importance for the functional integrity of the heart. Since DAF is abundantly expressed in epithelial an…

The Role of Osteoprotegerin and Its Ligands in Vascular Function

2019

International audience; The superfamily of tumor necrosis factor (TNF) receptors includes osteoprotegerin (OPG) and its ligands, which are receptor activators of nuclear factor kappa-B ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL). The OPG/RANKL/RANK system plays an active role in pathological angiogenesis and inflammation as well as cell survival. It has been demonstrated that there is crosstalk between endothelial cells and osteoblasts during osteogenesis, thus establishing a connection between angiogenesis and osteogenesis. This OPG/RANKL/RANK/TRAIL system acts on specific cell surface receptors, which are then able to transmit their signals to other intracellular comp…