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Injured Myocardium (injured + myocardium)
Selected AbstractsHydrogels as a Platform for Stem Cell Delivery to the HeartCONGESTIVE HEART FAILURE, Issue 3 2010Mazen Kurdi PhD Stem cell therapy offers great promise to repair the injured or failing heart. The outcomes of clinical trials to date, however, have shown that the actual benefit realized falls far short of the promise. A number of factors may explain why that is the case, but poor stem cell retention and engraftment in the hostile environment of the injured heart would seem to be a major factor. Improving stem cell retention and longevity once delivered would seem a logical means to enhance their reparative function. One way to accomplish this goal may be injectable hydrogels, which would serve to fix stem cells in place while providing a sheltering environment. Hydrogels also provide a means to allow for the paracrine factors produced by encapsulated stem cells to diffuse into the injured myocardium. Alternatively, hydrogels themselves can be used for the sustained delivery of reparative factors. Here the authors discuss chitosan-based hydrogels. Congest Heart Fail. 2010;16:132,135. © 2010 Wiley Periodicals, Inc. [source] Assessment of Myocardial Viability with Dobutamine Stress Echocardiography in Patients with Ischemic Left Ventricular DysfunctionECHOCARDIOGRAPHY, Issue 1 2005Siu-Sun Yao M.D. The noninvasive assessment of myocardial viability has proved clinically useful for distinguishing hibernating and/or stunned myocardium from irreversibly injured myocardium in patients with chronic ischemic heart disease or recent myocardial infarction, with marked regional and/or global left ventricular (LV) dysfunction. Noninvasive techniques utilized for the detection of viability in asynergic myocardial regions include positron emission tomographic imaging of residual metabolic activity, single photon emission tomography (SPECT) of radioisotope uptake with thallium-201, low-dose dobutamine echocardiography assessment of inotropic reserve and myocardial contrast echocardiography for evaluation of microvascular integrity. Of these techniques, dobutamine stress echocardiography is a safe, widely available and relatively inexpensive modality for the identification of myocardial viability for risk stratification and prognosis. Low-dose dobutamine response can accurately predict improvement of dysfunctional yet viable myocardial regions, and thus identify a subset of patients whose LV function will improve following successful coronary revascularization. [source] Potentiation of angiogenic response by ischemic and hypoxic reconditioning of the heartJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1 2002Nilanjana Maulik Abstract This review is intended to discuss the newly discovered role of preconditioning which should make it an attractive therapeutic stimulus for repairing the injured myocardium. We recently found that apart from rendering the myocardium tolerant to ischemic reperfusion injury, preconditioning also potentiates angiogenesis. Our study demonstrated for the first time that both ischemic and hypoxic preconditioning triggered myocardial angiogenesis at the capillary and arteriolar levels which nicely corroborated with the improved myocardial contractile function.Hypoxic preconditioning resulted in the stimulation of VEGF, the most potent angiogenic factor known to date. In concert, endothelial cell specific tyrosine kinase receptors, Tie 1, Tie 2 and Flt-1 and Flk-1 were also significantly enhanced in the preconditioned myocardium. The redox-regulated transcription factor NFkB was found to play an essential role in the preconditioning regulation of angiogenesis [source] Origin of cardiac progenitor cells in the developing and postnatal heartJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2010Elizabeth N. Kuhn The mammalian heart lacks the capacity to replace the large numbers of cardiomyocytes lost due to cardiac injury. Several different cell-based routes to myocardial regeneration have been explored, including transplantation of cardiac progenitors and cardiomyocytes into injured myocardium. As seen with cell-based therapies in other solid organ systems, inherent limitations, such as host immune response, cell death and long-term graft instability have hampered meaningful cardiac regeneration. An understanding of the cell biology of cardiac progenitors, including their developmental origin, lineage markers, renewal pathways, differentiation triggers, microenvironmental niche, and mechanisms of homing and migration to the site of injury, will enable further refinement of therapeutic strategies to enhance clinically meaningful cardiac repair. J. Cell. Physiol. 225: 321,325, 2010. © 2010 Wiley-Liss, Inc. [source] | ||||||||||