Objective To investigate the correlation between the left atrial hydrodynamic change and atrial fibrillation (AF) in the patients with rheumatic mitral stenosis. Methods According to cardiac rhythm before operation, 49 patients with rheumatic mitral stenosis accompanying chronic AF were divided into two groups,group A: AF, 25 cases; group B: sinus rhythm, 24 cases. Control group : 29 healthy volunteers were examined. By using echocardiography, left atrial hydrodynamics were tested, and repeated 6-8 months after the operation. Results Left atrial stress (LAS), left atriala area (LAA) and left atrial volume(LAV) in group A after operation was much lower than before operation, LAS after operation in group B was also lower than before operation(Plt;0.01). Before operation, LAS in group A was significantly lower than that in group B, LAA and LAVwere larger. After operation, LAA and LAV in group A were significantly larger than those in group B(Plt;0.01). LAS, LAA and LAV in group A and group B before and after operation were higher than those in control group. Conclusion Left atrial hydrodynamic enviroment in patients with mitral stenosis has not reached normal even after valve replacement, LAS may be an important factor of causing AF.
Objective To find new ways for wound healing and tissue expansion by reviewing of progress in recent years in functional molecules which are used for signaling channels of mechanical stress perception and mechanotransduction of keratinocyte. Methods The domestic and international articles were reviewed to summarize the functional molecules and signaling channels of mechanical stress perception and mechanotransduction of keratinocytes. Results The mechanism of mechanical stress perception includes mechano-sensitive channels, growth factor receptor-mediated mechanical stress perception, and mechanical stress perception by protein deformation. The mechanism of mechanotransduction includes cell adhesion-mediated signaling, mitogen-activated protein kinase signaling, the cytoskeleton and extracellular matrix, and so on. Conclusion Keratinocytes can response to the mechanical stress and transfer the effective information to undergo shaping, migration, proliferation, differentiation, and other biological behavior in order to adjust itself to adapt to the new environment.
Mechanical stress modulates almost all functions of cells. The key to exploring its biological effects lies in studying the perception of mechanical stress and its mechanism of mechanotransduction. This article details the perception and mechanotransduction mechanism of mechanical stress by extracellular matrix, cell membrane, cytoskeleton and nucleus. There are two main pathways for the perception and mechanotransduction of mechanical stress by cells, one is the direct transmission of force, and the other is the conversion of mechanical signal into chemical signal. The purpose of this study is to provide some reference for the exploration of precise treatment of mechanical stress-related diseases and the optimization of construction of tissue engineered organs by mechanical stress.