Functional adaptation: the key to plasticity of cardiovascular "stem" cells?

There is increasing evidence that cells of disparate phenotypes displaying various degrees of proliferative capacity engraft and function heterotopically in adult organisms. Efforts were made to reconcile these findings with the embryologic notions of pluripotent stem or progenitor cell, although the nature of the 'stemness' remained elusive. This topic is particularly important for the cardiovascular system, in which cytotrophoblasts, certain tumor cells, monocytes/macrophages, peritoneal mesothelial cells, and others acquire endothelial properties and/or perform endothelial functions. Here we suggest that this pluripotency reflects a fundamental characteristic of cellular diversity, which is manifested as the adaptive response to a functional pressure exerted by the cell's biochemical and biophysical microenvironments that would drive their differentiation. In this model, differentiation is a dynamic, reversible, and open-ended process where the cells would maintain the flexibility to respond to changing environmental clues with a fine tuning of their structure, a property that was previously called cellular plasticity. Pluripotent adult stem cells that display this property in culture, and, perhaps upon in vivo administration, were described. Therefore, we also suggest that differentiation of stem cells is a form of cellular plasticity within the larger context of functional adaptation, whereas their stemness remains associated with self-renewal.     

A Different Kind of Christmas Tree: Anomalous Origin of the Right Coronary Artery from the Pulmonary Artery (ARCAPA)

Anomalous right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital coronary anomaly that has an incidence of 0.002%. We report a case of a previously healthy female who presented to our hospital with pneumonia and was incidentally discovered to have ARCAPA. This was initially diagnosed on echocardiography by the unusual echocardiographic finding of multiple color flow Doppler signals around the right ventricular free wall and apex which were subsequently confirmed by angiography to be due to extensive collateral circulation between the left and right coronary arteries. This represents an unusual echocardiographic manifestation of this very rare condition.     

Flexural strength,biocompatibility, and antimicrobial activity of a polymethyl methacrylate denture resin enhanced with graphene and silver nanoparticles

Clinical Oral Investigations - The study evaluates the effect of adding graphene-Ag nanoparticles (G-AgNp) to a PMMA auto-polymerizing resin, with focus on antibacterial activity, cytotoxicity,...     

Systemic lupus erythematosus trials: successes and issues

PURPOSE OF REVIEW: The purpose of this review is to discuss the most recent published clinical trials for systemic lupus erythematosus and to identify important issues that have arisen in association with the search for new therapies for systemic lupus erythematosus, as well as new regimens or indications for the use of "standard-of-care" agents such as corticosteroids and cyclophosphamide. RECENT FINDINGS: Important developments have occurred during the past 2 years as interest in this area has increased, largely because of the participation of pharmaceutical and biotechnical companies in the development and testing of novel agents for systemic lupus erythematosus. Several important large-scale, multicenter, randomized controlled trials have been completed, but none has yet resulted in a new, approved indication for systemic lupus erythematosus. Many issues in the identification of new therapeutic modalities remain. These include the fact that a majority of published reports include either small numbers of patients in controlled trials that lack statistical power to draw conclusions, or are uncontrolled anecdotal series or individual case reports. Among the larger controlled trials, a pervasive issue in the failure to reach statistical significance may be the initial study design. Inclusion of patients with mild and/or stable disease activity does not allow for an effect size sufficient to show differences in treatment arms without recruitment of very large numbers of subjects. Finally, several potentially important trials have been reported only in abstract form to date. Further assessment of the results must await formal publication of these studies.