Cell Cycle–Mediated Cardiac Regeneration in the Mouse Heart

Purpose of Review Many forms of heart disease result in the essentially irreversible loss of cardiomyocytes. The ability to promote cardiomyocyte renewal may be a promising approach to reverse injury in diseased hearts. The purpose of this review is to describe the impact of cardiomyocyte cell cycle activation on cardiac function and structure in several different models of myocardial disease. Recent Findings Transgenic mice expressing cyclin D2 (D2 mice) exhibit sustained cardiomyocyte renewal in the adult heart. Earlier studies demonstrated that D2 mice exhibited progressive myocardial regeneration in experimental models of myocardial infarction, and that cardiac function was normalized to values seen in sham-operated litter mates by 180 days post-injury. D2 mice also exhibited markedly improved atrial structure in a genetic model of atrial fibrosis. More recent studies revealed that D2 mice were remarkably resistant to heart failure induced by chronic elevated afterload as compared with their wild type (WT siblings), with a 6-fold increase in median survival as well as retention of relatively normal cardiac function. Finally, D2 mice exhibited a progressive recovery in cardiac function to normal levels and a concomitant reduction in adverse myocardial remodeling in an anthracycline cardiotoxicity model. Summary The studies reviewed here make a strong case for the potential utility of inducing cardiomyocyte renewal as a means to treat injured hearts. Several challenges which must be met to develop a viable therapeutic intervention based on these observations are discussed

Load-Balancing Using Multi-path Directed Diffusion in Wireless Sensor Networks *

Abstract. Directed diffusion (DD) is a data-centric routing protocol based on purely local interactions between individual network nodes. This protocol uses application-specific context for data aggregation and dissemination. Therefore, it can be completely matched to the application requirements in a large distributed sensor network. Many work have been recently done to improve the energy efficiency of this protocol. In this paper, an extension to DD is presented in order to construct multiple paths between the sink and the sensor sources. Using this method, load-balancing is implemented to increase the life-time of the sensor nodes collaborating in the routing process. The proposed protocol, Multi-path directed diffusion (MDD), can produce more than one disjoint or braided paths and spread the data collected in the sources, properly between the paths. In this way, an efficient load balancing mechanism has been implemented. The simulation results show that through using MDD, the lifetime of the network connections between the sources and the sink will be increased and the interest flooding rate which is proved to be an expensive operation can be reduced

Effects of six-week exercise training protocol on pain relief in patients with lumbar disc herniation

Introduction: Paraspinal, abdominal, and core muscles are playing the main role in lumbar disc herniation. The aim of the present study was to investigate the efficacy of a 6 weeks exercise training protocol on pain relief in males and females with lumbar disc herniation. Methods: In this before-after trial study, 64 patients with lumbar disc herniation were assigned to a 6 weeks exercise training program. Training protocol included leg press, trunk lateral flexion, trunk rotation, trunk flexion/extension, and stretching exercises in two sessions a week with 25-30 minutes each. Pain was measured with visual analog scale (VAS) at 1st, 6th, and 12th sessions. Results: A total of 64 patients (13 males with mean age 47.53 ± 11.71 years and 51 females with mean age 46.50 ± 11.76 years) completed the protocol. The pain was significantly reduced in both males and females during sessions 6 and 12 in comparison with the first session (P = 0.001). The amount of pain relief in males was higher than females (P = 0.047). Conclusion: About 6 weeks exercise training program could reduce more pain in males with lumbar disc herniation compared to females. This core stabilizing exercise protocol could be a good recommendation for patients with disk herniated low back pain (LBP)