http://www.ncbi.nlm.nih.gov:80 – Forces associated with blood flow are major determinants of vascular morphogenesis and physiology. Blood flow is crucial for blood vessel development during embryogenesis and for regulation of vessel diameter in adult life. It is also a key factor in atherosclerosis, which, despite the systemic nature of major risk factors, occurs mainly at regions of arteries that experience disturbances in fluid flow. Read more »

http://arjournals.annualreviews.org – The formation of an arterial aneurysm is believed to be a multifactorial and predominantly degenerative process, resulting from a complex interplay between biological processes in the arterial wall and the hemodynamic stimuli on the vessel's wall. Once an aneurysm forms, the repetitive pressure and shear stresses exerted by the blood flow on the weakened arterial wall generally, but not always, cause a gradual expansion. Read more »

http://jdr.sagepub.com – Orthodontic tooth movement is achieved by (re)modeling processes of the alveolar bone, which are triggered by changes in the stress/strain distribution in the periodontium. In the past, the finite element (FE) method has been used to describe the stressed situation within the periodontal ligament (PDL) and surrounding alveolar bone. The present study sought to determine the impact of the modeling process on the outcome from FE analyses and to relate these findings to the current theories on orthodontic tooth movement. Read more »

http://www.ncbi.nlm.nih.gov – Mechanical loading is a powerful regulator of tissue properties in engineered cardiovascular tissues. To ultimately regulate the biochemical processes, it is essential to quantify the effect of mechanical loading on the properties of engineered cardiovascular constructs. In this study the Flexercell FX-4000T (Flexcell Int. Corp., USA) straining system was modified to simultaneously apply various strain magnitudes to individual samples during one experiment. Read more »

http://www.sciencedirect.com – Summary Objective Osteoarthritis is a disease process of cellular degradation of articular cartilage caused by mechanical loads and inflammatory cytokines. We studied the cellular response in native cartilage subjected to a mechanical load administered simultaneously with an inflammatory cytokine interleukin-1 (IL-1), hypothesizing that the combination of load and cytokine would result in accelerated extracellular matrix (ECM) degradation. Methods Read more »

http://www.ncbi.nlm.nih.gov – Vascular endothelial cell migration, which plays an important role in vascular remodeling, is known to be regulated by hemodynamic forces in the blood vessels. When shear stress is applied on mouse microvessel endothelial cells (bEnd.3) in vitro, cells exhibit upstream migration behavior with respect to the direction of the flow. To determine how shear stress magnitude influences mechanotaxis of the cells, endothelial cells were exposed to different magnitudes of unidirectional shear stress. Read more »

http://www.sciencedirect.com – Background Passive constraint is used to prevent left ventricular dilation and subsequent remodeling. However, there has been concern about the effect of passive constraint on diastolic left ventricular chamber stiffness and pump function. This study determined the relationship between constraint, diastolic wall stress, chamber stiffness, and pump function. We tested the hypothesis that passive constraint at 3 mm Hg reduces wall stress with minimal change in pump function. Methods Read more »

http://www.sciencedirect.com – This bone mechanosensory hypothesis is partially sustained by experi- mental evidence and model calculations that will be described. The ques- tions addressed by these studies include the following: (a) Which cells (osteoblasts, osteocytes, bone-lining cells) are the bone mechanosensors? (b) What mechanical stimulus activates the mechanosensor? And (c) How is a local mechanical signal translated into an anabolic or catabolic event? Over the last decade, important progress has been made related to these questions, that will be reviewed here. Read more »

http://www.sciencedirect.com – A three-dimensional finite element model was used to explore whether or not transmural distributions of end-diastolic and end-systolic fiber stress are uniform from the apex to the base of the canine left ventricular wall. An elastance model for active fiber stress was incorporated in an axisymmetric model that accurately represented the geometry and fiber angle distribution of the anterior free wall. The nonlinear constitutive equation for the resting myocardium was transversely isotropic with respect to the local fiber axis. Read more »

http://ajpheart.physiology.org – Using a frequency-domain Womersley-type model, we previously simulated pulsatile blood flow throughout the coronary arterial tree. Although this model represents a good approximation for the smaller vessels, it does not take into account the nonlinear convective energy losses in larger vessels. Here, using Womersley's theory, we present a hybrid model that considers the nonlinear effects for the larger epicardial arteries while simulating the distal vessels (down to the 1st capillary segments) with the use of Womersley's Theory. Read more »