and the tail from a head piece.Stem cells are multipotent cells capable of differentiating into a variety of cell types, including muscle cells. It was originally hypothesized that stem cells implanted into the myocardial milieu would differentiate into cardiomyocytes to replace those lost during the myocardial infarction. Animal studies demonstrated that stem cell transplantation was safe and potentially efficacious. Bone-marrow-derived stem cells, endothelial progenitor cells and stem cells isolated from adipose tissue have been the most widely used for implantation into the injured myocardium. Theencouraging results of the preclinical studies triggered a number of clinical trials. The early clinical trials established the feasibility of stem cell therapy to repair the injured myocardium. Unfortunately, the clinical benefits of cell transplantation were not as successful as anticipated from preclinical studies. Recently reported meta-analyses demonstrated that cell therapy was effective, but the results were not as dramatic as expected. However, the efficacy of cell therapy
compares favorably with currently recommended medical therapy. Multiple reasons for the discrepancy between the results obtained in preclinical studies and the initial clinical trials have been postulated, and many of these proposals have been evaluated. New techniques were developed to improve cell implantation, and adjuncts were added to enhance cell retention. In addition, the effects of comorbidity and patient age were found to contribute to the diminished beneficial effects observed in the clinical trials. With continuing improvements in the techniques of cell transplantation, the benefits should also increase.
You've reached the end of your free preview.
Want to read both pages?
- Fall '11