A5101832571- Cardiovascular Function and Risk Factors
- Elasticity and Material Modeling
- Cardiac Structural Anomalies and Repair
- Tissue Engineering and Regenerative Medicine
- Electrospun Nanofibers in Biomedical Applications
- Cardiac Fibrosis and Remodeling
- Cardiomyopathy and Myosin Studies
- Cardiac pacing and defibrillation studies
- Cardiac Arrhythmias and Treatments
- Cardiac Valve Diseases and Treatments
- Cellular Mechanics and Interactions
- Cardiac electrophysiology and arrhythmias
- Mechanical Circulatory Support Devices
- Advanced MRI Techniques and Applications
- Cardiac Imaging and Diagnostics
- Collagen: Extraction and Characterization
- Tendon Structure and Treatment
- Ultrasound Imaging and Elastography
- Coronary Interventions and Diagnostics
- Signaling Pathways in Disease
- Cardiac Arrest and Resuscitation
- Cardiovascular Effects of Exercise
- Heart Failure Treatment and Management
- Muscle Physiology and Disorders
- Medical Image Segmentation Techniques
Maine Medical Center
2024
Tufts University
2024
University of Virginia
2013-2023
University of Alabama at Birmingham
2020-2023
University of Virginia Health System
2012-2021
Holmes Community College
2021
University of Alabama System
2020
University of South Carolina
1999-2016
Albert Einstein College of Medicine
2016
G.V. (Sonny) Montgomery VA Medical Center
2016
Hypertrophic scars occur following cutaneous wounding and result in severe functional esthetic defects. The pathophysiology of this process remains unknown. Here, we demonstrate for the first time that mechanical stress applied to a healing wound is sufficient produce hypertrophic mice. resulting are histopathologically identical human persist more than six months brief (one-week) period augmented during proliferative phase healing. Resulting structurally showed dramatic increases volume...
Myocardial infarction is a prevalent major cardiovascular event that arises from myocardial ischemia with or without reperfusion, and basic translational research needed to better understand its underlying mechanisms consequences for cardiac structure function. Ischemia underlies broad range of clinical scenarios ranging angina hibernation permanent occlusion, while reperfusion mandatory salvage ischemic injury, also inflicts injury on own. In this consensus statement, we present...
Dysregulation of oxidative phosphorylation is associated with increased mitochondrial reactive oxygen species production and some the most prevalent human diseases including obesity, cancer, diabetes, neurodegeneration, heart disease. Chemical 'mitochondrial uncouplers' are lipophilic weak acids that transport protons into matrix via a pathway independent ATP synthase, thereby uncoupling nutrient oxidation from production. Mitochondrial uncouplers also lessen proton motive force across inner...
Left ventricular (LV) assist devices (LVADs) can improve contractile strength and normalize characteristics of the Ca(2+) transient in myocytes isolated from failing human hearts. The purpose present study was to determine whether LVAD support also improves at different frequencies contraction (the force-frequency relationship [FFR]) intact myocardium alters expression genes encoding for proteins involved handling.The isometric FFRs LV trabeculae 15 patients with end-stage heart failure were...
The central problem in modelling the multi–dimensional mechanics of heart is identifying functional forms and parameters constitutive equations, which describe material properties resting active, normal diseased myocardium. myocardium are three dimensional, anisotropic, nonlinear time dependent. Formulating useful laws requires a combination multi–axial tissue testing vitro, microstructural based on quantitative morphology, statistical parameter estimation, validation with measurements from...
Left ventricular assist devices (LVAD) reverse ventricular, myocardial, and systemic abnormalities characteristic of severe heart failure (reverse remodeling). The relative contributions hemodynamic unloading normalized biochemical milieu to remodeling are unknown.Structural functional characteristics were measured from 53 hearts patients undergoing transplantation without LVAD support (medical support) 33 receiving a median 46 days (range, 8 360 days). Compared with medical alone, for >/=30...
The mechanical properties of the healing scar are an important determinant heart function following myocardial infarction. Yet relationship between structure, mechanics, and ventricular remains poorly understood, in part because no published study has tracked all these factors simultaneously any animal model. We therefore studied temporal evolution left (LV) large anterior infarcts rats. At 1, 2, 3, 6 wk after descending coronary ligation, we examined LV using sonomicrometry, infarct biaxial...
The ability of cells to orient in response mechanical stimuli is essential embryonic development, cell migration, mechanotransduction, and other critical physiologic functions a range organs. Endothelial cells, fibroblasts, mesenchymal stem osteoblasts all perpendicular an applied cyclic stretch when plated on stretchable elastic substrates, suggesting common underlying mechanism. However, many these same parallel vivo 3D culture, compelling explanation for the different orientation...
Electrical and mechanical anisotropy arise from matrix cellular alignment in native myocardium. Generation of engineered heart tissue will be required to match properties provide immediate opportunities investigate the genesis structural determinants functional anisotropy. We investigated influence geometry boundary conditions on fibroblast thin collagen gels. Consistent with previous reports, we found that human dermal fibroblasts align parallel free edges partially constrained gels;...
An in vitro model system was developed to study structure-function relationships and the development of structural mechanical anisotropy collagenous tissues. Fibroblast-populated collagen gels were constrained either biaxially or uniaxially. Gel remodeling, biaxial properties, orientation determined after 72h culture. Collagen contracted spontaneously unconstrained direction, uniaxial constraints produced anisotropy, this associated with anisotropy. Cardiac tendon fibroblasts compared test...
Myocardial elastography (ME), a radio frequency (RF)-based speckle tracking technique with one-dimensional (1-D) cross correlation and novel recorrelation methods in 2-D search was proposed to estimate fully image 2-1) transmural deformation field detect abnormal cardiac function. A theoretical framework first developed order evaluate the performance of myocardial based on previously 3-D finite-element model canine left ventricle. normal (control) an ischemic (left-circumflex, LCx) model,...
Effective management of healing and remodelling after myocardial infarction is an important problem in modern cardiology practice. We have recently shown that the level infarct anisotropy a critical determinant heart function following large anterior infarction, which suggests therapeutic gains may be realized by controlling anisotropy. However, factors regulating are not well understood. Mechanical, structural chemical guidance cues all been to regulate alignment fibroblasts collagen vitro,...
This paper presents a method of four-dimensional (4-D) (3-D+Time) space-frequency analysis for directional denoising and enhancement real-time three-dimensional (RT3D) ultrasound quantitative measures in diagnostic cardiac ultrasound. Expansion echocardiographic volumes is performed with complex exponential wavelet-like basis functions called brushlets. These offer good localization time frequency decompose signal into distinct patterns oriented harmonics, which are invariant to intensity...
During healing after myocardial infarction, scar collagen content and stiffness do not correlate. We studied regional mechanics both area fraction orientation of large fibers 3 wk coronary ligation in the pig. passive inflation isolated, arrested hearts, tissue demonstrated significantly less circumferential strain but similar longitudinal radial deformation comparison with noninfarcted regions same hearts. The observed selective resistance to was consistent finding that most were oriented...
Loss of skeletal muscle profoundly affects the health and well-being patients, there currently is no way to replace lost muscle. We believe that a key step in development prosthesis for reconstruction dysfunctional muscular tissue ability reconstitute vivo-like 3-dimensional (3D) organization vitro with isolated satellite cells. In our present proof principle studies, we have successfully constructed multilayered culture cells, derived from neonatal are distributed 3D pattern mimics many...