Search results for "Cardiac"

Biomaterials and bioactive molecules to drive differentiation in striated muscle tissue engineering

2015

International audience; The generation of engineered tissues and organs has entered into the clinical practice in response to the chronic lack of organ donors. In particular, for the skeletal and cardiac muscles the translational potential of tissue engineering approaches has clearly been shown, even though the construction of these tissues lags behind others given the hierarchical, highly organized architecture of striated muscles. Failure of the cardiac tissue leads to cardiovascular diseases, which are the leading cause of death in the developed world (Di Felice et al., 2014). On the other hand, there are many clinical cases where the loss of skeletal muscle due to a traumatic injury, an…

Assessment of blood pressure early morning rise

2002

Myocardial bridge pathology and preventable accidents during physical activity of healthy subjects: A case report and a literature review.

2020

Myocardial bridging is a congenital coronary pathology described as a segment of coronary artery which courses through the myocardial wall under the muscle bridge. Although the prognosis of myocardial bridging is benign, sports medicine recognises myocardial bridging as a leading cause of sudden death among young basketball, football and soccer players. The authors report a case of a 42-year-old man who collapsed while playing football. He died notwithstanding prompt medical assistance and cardiopulmonary resuscitation. At autopsy, gross examination of the heart revealed the intramural course of the left anterior descending coronary artery to be 2 cm from its coronary ostial origin. Histol…

Using FFR to Detect Ischemia in Myocardial Bridge Lesions

2016

Beyond atherosclerosis, a number of other phenomena may result in cardiac ischemia. Among these, extracoronary compression due to myocardial bridges may cause a dynamic stenosis and typical angina. The assessment of the hemodynamic relevance and the treatment of such lesions have unique characteristics that are due to the fact that extracoronary compression from myocardial bridges is mostly a systolic phenomenon and is dependent on the inotropic state. The consequence is that other hyperemic stimuli, such as dobutamine, may be more adequate to unveil ischemia in these settings.

Cutting Edge: IL-1α Is a Crucial Danger Signal Triggering Acute Myocardial Inflammation during Myocardial Infarction

2016

Abstract Myocardial infarction (MI) induces a sterile inflammatory response that contributes to adverse cardiac remodeling. The initiating mechanisms of this response remain incompletely defined. We found that necrotic cardiomyocytes released a heat-labile proinflammatory signal activating MAPKs and NF-κB in cardiac fibroblasts, with secondary production of cytokines. This response was abolished in Myd88−/− fibroblasts but was unaffected in nlrp3-deficient fibroblasts. Despite MyD88 dependency, the response was TLR independent, as explored in TLR reporter cells, pointing to a contribution of the IL-1 pathway. Indeed, necrotic cardiomyocytes released IL-1α, but not IL-1β, and the immune acti…

αB-crystallin activation in cardiac muscle by acute exercise mirrors the sHSP kinetic in oxidative skeletal muscle fibers: animal and cellular study

2017

Alpha-B-Crystallin (CRYAB), a Small Heat Shock Protein sensitive to oxidative stress, is implicated in various biological processes in many tissues. In cardiac muscle, CRYAB exerts a cardio protective role in ischemia-induced damage preventing apoptosis and necrosis. We aimed to study αB-crystallin’ response in mouse cardiac tissue (H), at different time of recovery from an acute aerobic exercise (1 hour), correlating its modulation with oxidative stress level. We found that a single bout exercise lead to a specific short-term increase of phospho-αB-crystallin level (pCRYAB), without changes of its total expression. Further, the level of 4-hydroxynonenal, a marker of lipidic peroxidation, h…

Model predictions of the ionic mechanisms underlying the beating and bursting pacemaker characteristics of molluscan neurons

1976

The general properties of the excitable membrane on molluscan pacemaker neurons can be described on the basis of a fair amount of experimental evidence available in the literature. The neuronal membrane exhibits under voltage clamp an initial inward current carried by both Na+ and Ca2+ ions, the time- and voltage-dependent characteristics of which are similar to that of other excitable structures. The conductance mechanism for the two ion species and the transport kinetics appear to be closely similar. The time course and amplitude of the delayed outward current carried by K+ ions shows a marked dependence on the membrane potential. Characteristic for the molluscan neurons is the existence …

Parameters analysis of FitzHugh-Nagumo model for a reliable simulation

2014

International audience; Derived from the pioneer ionic Hodgkin-Huxley model and due to its simplicity and richness from a point view of nonlinear dynamics, the FitzHugh-Nagumo model has been one of the most successful neuron / cardiac cell model. It exists many variations of the original FHN model. Though these FHN type models help to enrich the dynamics of the FHN model. The parameters used in these models are often in biased conditions. The related results would be questionable. So, in this study, the aim is to find the parameter thresholds for one of the commonly used FHN model in order to pride a better simulation environment. The results showed at first that inappropriate time step and…

Acute Hemodynamic Effects of Nicorandil in Coronary Artery Disease

1992

Nicorandil is a potent vasodilator with antianginal and anti-ischemic properties that acts on both the coronary and the peripheral vascular bed. Because of its dual vasodilatory mechanisms mediated by an increase in cyclic GMP similar to that of nitrates and by a selective increase in the K+ conductance of the smooth muscle cell membrane, nicorandil unloads the right and left ventricles at rest and during exercise. Thus, compared with the classic nitrates, nicorandil is a more balanced vasodilator, i.e., it affects not only the venous capacitance vessels (as predominantly affected by nitrates) but also the arterial resistance vessels. In clinical pharmacologic trials, nicorandil has been ad…

HSP90 and eNOS partially co-localize and change cellular localization in relation to different ECM components in 2D and 3D cultures of adult rat card…

2007

Background information. Cultivation techniques promoting three-dimensional organization of mammalian cells are of increasing interest, since they confer key functionalities of the native ECM (extracellular matrix) with a power for regenerative medicine applications. Since ECM compliance influences a number of cell functions, Matrigel-based gels have become attractive tools, because of the ease with which their mechanical properties can be controlled. In the present study, we took advantage of the chemical and mechanical tunability of commonly used cell culture substrates, and co-cultures to evaluate, on both two- and three-dimensional cultivated adult rat cardiomyocytes, the impact of ECM c…