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The ability to engineer or regenerate lost myocardial tissue caused by injury, aging, disease, or genetic abnormality holds great promise. The vision is to generate significant mass of functional heart muscle tissue. However, the area of myocardial tissue engineering still faces significant difficulties. Scientists are still searching for cell types other than cardiomyocytes. Novel approaches are warranted for material processing to create bioactive scaffolds, which would allow composition of the evolving myocardial structure. There is a need for development of strategies to promote vascularization and/or innervations within engineered myocardial tissue. Other important goals include achievement of immunologic tolerance for engineered constructs and increased understanding of the basic principles governing tissue formation, function, and failure, including the assembly of multiple cell types and biomaterials into multidimensional structures that mimic the architecture and function of native myocardial tissue.

In addition to laboratory-grown myocardial tissue, more research is warranted in the area of cardiac self-repair and regenerating functional myocardium in situ. If successful, these strategies could be used for surgical repair of the infarcted myocardium or congenital cardiac defects and would have a dramatic impact on the future of cardiovascular medicine and public health.

Regenerative medicine efforts are currently being undertaken for every type of tissue and organ, including the bladder, within the urinary system. Most of the effort expended to engineer bladder tissue has occurred within the last decade. Personnel who have mastered the techniques of cell harvest, culture, and expansion as well as polymer design are essential for the successful application of this technology. Various applications of engineered bladder tissues are at different stages of development, with some already being used clinically, a few in preclinical trials, and some in the discovery stage. Recent progress suggests that engineered bladder tissues may have an expanded clinical applicability in the future.

The derivation of the hESC lines and the resulting cardiomyocyte differentiation system may bring a unique value to several basic and applied research fields. Research based on the cells may help to elucidate the mechanisms involved in early human cardiac lineage commitment, differentiation, and maturation. Moreover, this research may promote the discovery of novel growth and transcriptional factors using gene trapping techniques, functional genomics, and proteomics as well as providing a novel in vitro model for drug development and testing. Finally, the ability to generate, in vitro for the first time, human cardiac tissue provides an exciting and promising cell source for the emerging discipline of regenerative medicine and myocardial repair.

The clinical need for therapeutic approach aimed to alleviate symptoms in “no option” patients with coronary artery disease is growing. The negative results of several phase II studies raise concerns regarding the potential of the single growth factor approach. Administration of BM cells and peripheral blood-derived mononuclear and progenitor cells is a novel therapeutic strategy derived from the hypothesis that meaningful therapeutic angiogenesis can be achieved by local delivery of cells capable of secreting multiple growth factors and cytokines in a timely, coordinated manner. These cells may also have the potential to differentiate into a variety of vascular cells. Results obtained from multiple, small phase I studies suggest safety and feasibility of this approach. Cell delivery seems also to improved myocardial perfusion and function. This encouraging initial experience together with new data derived from novel animal studies and added knowledge at the molecular and cellular levels widen the horizons for this novel strategy.

Cell therapy is a relatively novel approach to the treatment of heart failure. Although the initial aims of completely rebuilding scarred myocardium by contractile tissue, thereby completely restoring cardiac pumping capacity, have not yet been accomplished, many experimental studies reported beneficial effects on left ventricular performance, most of them attributed to less ventricular dilation, scar thickening, and reduction of infarct expansion. Synchronous beating of the graft in the infarcted territory with the host has not been undoubtedly proven, although it seems to be likely that effective cell-to-cell coupling between the host and graft with propagation of calcium transients and in consequence propagation of contraction is possible after transplantation. A major obstacle in completely restoring regional contractile force seems to be the incomplete integration of the graft into the host and the separation from host cells by connective tissue and the scar. For effectively restoring regional contractile function, this will be the most important issue to be solved.

Nonetheless, transplantation appears to exhibit beneficial effects on myocardial performance that can at least in part be ascribed to less ventricular remodeling. Thus, it is likely that progression of heart failure over time can be attenuated to a certain degree by cell therapy. Paradoxically, the fundamental idea of restoring pumping capacity of the heart by cell therapy originates in a cardiocirculatory model of cardiac failure, but many effects of cellular cardiomyoplasty may be attributed to beneficial effects on the remodeling process of the ventricle, resembling other therapeutical approaches derived from a progressive model of heart failure.

Whether less ventricular dilation and less infarct expansion translate into better outcome over time and survival, improved symptoms, and exercise capacity remains to be investigated. Most importantly, for potential clinical applications, cell therapy will need to be compared with the best medical and interventional treatment strategies when evaluating its potential benefit for the patient with heart failure.

Neural precursor cells that reside in the adult brain, a potential source of myelin-forming cells, do not produce effective remyelination in MS. The transplantation of exogenous cells, as an alternative source of remyelinating cells, has been pursued as a very active research area over the last decade and remarkable progress has been obtained. New sources of myelinating cells were characterized and different transplantation strategies have been proposed. Better understanding of the pros and cons of using each of the various remyelinating cell types, of the different routes of cell delivery, and of methods for cell tracking, form the basis for designing cell transplantation strategies in the clinic. Better understanding of the process of remyelination and insights into the mechanism of action of transplanted cells are still needed to optimize cell therapy in demyelinating diseases.

The ability to engineer or regenerate lost myocardial tissue caused by injury, aging, disease, or genetic abnormality holds great promise. The vision is to generate significant mass of functional heart muscle tissue. However, the area of myocardial tissue engineering still faces significant difficulties. Scientists are still searching for cell types other than cardiomyocytes. Novel approaches are warranted for material processing to create bioactive scaffolds, which would allow composition of the evolving myocardial structure. There is a need for development of strategies to promote vascularization and/or innervations within engineered myocardial tissue. Other important goals include achievement of immunologic tolerance for engineered constructs and increased understanding of the basic principles governing tissue formation, function, and failure, including the assembly of multiple cell types and biomaterials into multidimensional structures that mimic the architecture and function of native myocardial tissue.

In addition to laboratory-grown myocardial tissue, more research is warranted in the area of cardiac self-repair and regenerating functional myocardium in situ. If successful, these strategies could be used for surgical repair of the infarcted myocardium or congenital cardiac defects and would have a dramatic impact on the future of cardiovascular medicine and public health.

XP is a social activity as well as a technical activity. The social side of XP is emphasized typically in the values and principles which underlie the technical practices. However, the fieldwork studies we have carried out with mature XP teams have shown that the technical practices themselves are also intensely social: they have social dimensions that arise from and have consequences for the XP approach. In this paper, we report on elements of XP practice that show the social side of several XP practices, including test-first development, simple design, refactoring and on-site customer. We also illustrate the social side of the practices in combination through a thematic view of progress.

There are a number of advantages and disadvantages with the use of adult or ES cells for application in patients; however, for the therapeutic administration of human ES cells to be an option, the rejection of cells by the immune system will have to be addressed. Although the immune response should be less intense than the response to xenotransplants, the major histocompatibility complex differences between human ES cells and a recipient will require immunosuppression (e.g., ref. 133), the extent of which must be determined for the transplantation of cells into the epidermis. It is conceivable that stem cell-based therapy alone will not be the ultimate solution for the treatment of epidermal damage and loss of regeneration, and that therapies of the distant future might be a combination of stem cell transplantation, gene therapy, and drug treatment. Such a combination of therapies will be customized to the particular cellular ailment of the individual patient. At this point, it is difficult to predict how stem cell-based therapy will be translated into clinical practice for epidermal tissues. Some of the limitations and potential issues regarding ES cell and adult stem cell plasticity have been discussed; nevertheless, the promise is real and basic science advances continue to spur new skin cell biology that holds promise for novel skin cell therapeutics.

Cell therapy is a relatively novel approach to the treatment of heart failure. Although the initial aims of completely rebuilding scarred myocardium by contractile tissue, thereby completely restoring cardiac pumping capacity, have not yet been accomplished, many experimental studies reported beneficial effects on left ventricular performance, most of them attributed to less ventricular dilation, scar thickening, and reduction of infarct expansion. Synchronous beating of the graft in the infarcted territory with the host has not been undoubtedly proven, although it seems to be likely that effective cell-to-cell coupling between the host and graft with propagation of calcium transients and in consequence propagation of contraction is possible after transplantation. A major obstacle in completely restoring regional contractile force seems to be the incomplete integration of the graft into the host and the separation from host cells by connective tissue and the scar. For effectively restoring regional contractile function, this will be the most important issue to be solved.

Nonetheless, transplantation appears to exhibit beneficial effects on myocardial performance that can at least in part be ascribed to less ventricular remodeling. Thus, it is likely that progression of heart failure over time can be attenuated to a certain degree by cell therapy. Paradoxically, the fundamental idea of restoring pumping capacity of the heart by cell therapy originates in a cardiocirculatory model of cardiac failure, but many effects of cellular cardiomyoplasty may be attributed to beneficial effects on the remodeling process of the ventricle, resembling other therapeutical approaches derived from a progressive model of heart failure.

Whether less ventricular dilation and less infarct expansion translate into better outcome over time and survival, improved symptoms, and exercise capacity remains to be investigated. Most importantly, for potential clinical applications, cell therapy will need to be compared with the best medical and interventional treatment strategies when evaluating its potential benefit for the patient with heart failure.