Tricuspid valve leaflet remodeling in sheep with biventricular heart failure: A comparison between leaflets.

Tricuspid valve leaflets are dynamic tissues that can respond to altered biomechanical and hemodynamic loads. Each leaflet has unique structural and mechanical properties, leading to different in vivo strains. We hypothesized that these intrinsic differences drive heterogeneous, disease-induced remodeling between the leaflets.

Tricuspid valve leaflet remodeling in sheep with biventricular heart failure: A comparison between leaflets.

Tricuspid valve leaflets are dynamic tissues that can respond to altered biomechanical and hemodynamic loads. Each leaflet has unique structural and mechanical properties, leading to differential strains. We hypothesized that these intrinsic differences drive heterogeneous, disease-induced remodeling between the leaflets.

Sex- and age-dependent skin mechanics-A detailed look in mice.

Skin aging is of immense societal and, thus, scientific interest. Because mechanics play a critical role in skin's function, a plethora of studies have investigated age-induced changes in skin mechanics. Nonetheless, much remains to be learned about the mechanics of aging skin.

Texas TriValve 1.0 : a reverse‑engineered, open model of the human tricuspid valve.

Nearly 1.6 million Americans suffer from a leaking tricuspid heart valve. To make matters worse, current valve repair options are far from optimal leading to recurrence of leakage in up to 30% of patients.

Sex- and Age-dependent Skin Mechanics - A Detailed Look in Mice.

Skin aging is of immense societal and, thus, scientific interest. Because mechanics play a critical role in skin's function, a plethora of studies have investigated age-induced changes in skin mechanics. Nonetheless, much remains to be learned about the mechanics of aging skin.

Biomechanical phenotyping of minuscule soft tissues: An example in the rodent tricuspid valve.

The biomechanical phenotype of soft tissues - i.e., the sum of spatially- and directionally-varying mechanical properties - is a critical marker of tissue health and disease.

Biaxial mechanics of thermally denaturing skin - Part 2: Modeling.

Understanding the response of skin to superphysiological temperatures is critical to the diagnosis and prognosis of thermal injuries, and to the development of temperature-based medical therapeutics. Unfortunately, this understanding has been hindered by our incomplete knowledge about the nonlinear coupling between skin temperature and its mechanics. In Part I of this study we experimentally demonstrated a complex interdependence of time, temperature, direction, and load in skin's response to superphysiological temperatures.

Biaxial mechanics of thermally denaturing skin - Part 1: Experiments.

The mechanics of collagenous soft tissues, such as skin, are sensitive to heat. Thus, quantifying and modeling thermo-mechanical coupling of skin is critical to our understanding of skin's physiology, pathophysiology, and its treatment. However, key gaps persist in our knowledge about skin's coupled thermo-mechanics.

Right ventricular myocardial mechanics: Multi-modal deformation, microstructure, modeling, and comparison to the left ventricle.

The right ventricular myocardium, much like the rest of the right side of the heart, has been consistently understudied. Presently, little is known about its mechanics, its microstructure, and its constitutive behavior. In this work, we set out to provide the first data on the mechanics of the mature right ventricular myocardium in both simple shear and uniaxial loading and to compare these data to the mechanics of the left ventricular myocardium.

The tricuspid valve also maladapts as shown in sheep with biventricular heart failure.

Over 1.6 million Americans suffer from significant tricuspid valve leakage. In most cases this leakage is designated as secondary.

Tricuspid Valve Annuloplasty Alters Leaflet Mechanics.

Tricuspid valve regurgitation is associated with significant morbidity and mortality. Its most common treatment option, tricuspid valve annuloplasty, is not optimally effective in the long-term. Toward identifying the causes for annuloplasty's ineffectiveness, we have previously investigated the technique's impact on the tricuspid annulus and the right ventricular epicardium.

A detailed mechanical and microstructural analysis of ovine tricuspid valve leaflets.

The tricuspid valve ensures unidirectional blood flow from the right atrium to the right ventricle. The three tricuspid leaflets operate within a dynamic stress environment of shear, bending, tensile, and compressive forces, which is cyclically repeated nearly three billion times in a lifetime. Ostensibly, the microstructural and mechanical properties of the tricuspid leaflets have mechanobiologically evolved to optimally support their function under those forces.

The Effect of Downsizing on the Normal Tricuspid Annulus.

Tricuspid annuloplasty is a surgical procedure that cinches the valve's annulus in order to reduce regurgitant blood flow. One of its critical parameters is the degree of downsizing. To provide insight into the effect of downsizing, we studied the annulus of healthy sheep during suture annuloplasty.

The regional-dependent biaxial behavior of young and aged mouse skin: A detailed histomechanical characterization, residual strain analysis, and constitutive model.

Skin fulfills several vital functions, many of which are dependent on its mechanical properties. Therefore, as mice have become an invaluable model for skin research, determining murine skin's mechanical properties is important. Specifically, skin's mechanical properties are important for functional tests as well as for prognostic and diagnostic purposes.

Biomechanics of the Tricuspid Annulus: A Review of the Annulus' Dynamics With Emphasis on Ovine Data.

The tricuspid annulus forms the boundary between the tricuspid valve leaflets and their surrounding perivalvular tissue of the right atrioventricular junction. Its shape changes throughout the cardiac cycle in response to the forces from the contracting right heart myocardium and the blood-valve interaction. Alterations to annular shape and dynamics in disease lead to valvular dysfunctions such as tricuspid regurgitation from which millions of patients suffer.

A fiduciary marker-based framework to assess heterogeneity and anisotropy of right ventricular epicardial strains in the beating ovine heart.

Quantifying ventricular deformation in health and disease is critical to our understanding of normal heart function, heart disease mechanisms, and the effect of medical treatments. Imaging modalities have been developed that can measure ventricular deformation non-invasively. However, because of the small thickness, complex shape, and anatomic position of the right ventricle, using these technologies to determine its deformation remains challenging.

The Effect of Acute Pulmonary Hypertension on Tricuspid Annular Height, Strain, and Curvature in Sheep.

The tricuspid annulus shows significant alterations in patients with functional tricuspid regurgitation-tricuspid valve dysfunction that is secondary to other diseases such as pulmonary hypertension. Early changes in annular shape and dynamics may provide an understanding of disease mechanisms and could predict disease progression. To gain a mechanistic insight into these early changes we perform a spatially-resolved analysis of the effect of acute pulmonary hypertension on the tricuspid annulus in sheep.

Implications of chronic daily anti-oxidant administration on the inflammatory response to intracortical microelectrodes.

Objective: Oxidative stress events have been implicated to occur and facilitate multiple failure modes of intracortical microelectrodes. The goal of the present study was to evaluate the ability of a sustained concentration of an anti-oxidant and to reduce oxidative stress-mediated neurodegeneration for the application of intracortical microelectrodes.

Approach: Non-functional microelectrodes were implanted into the cortex of male Sprague Dawley rats for up to sixteen weeks.

A comparison of neuroinflammation to implanted microelectrodes in rat and mouse models.

Rat models have emerged as a common tool to study neuroinflammation to intracortical microelectrodes. While a number of studies have attempted to understand the factors resulting in neuroinflammation using rat models, a complete understanding of key mechanistic pathways remains elusive. Transgenic mouse models, however, could facilitate a deeper understanding of mechanistic pathways due to an ease of genetic alteration.