Comparison of Anthropometry and Body Composition Using Air Displacement Plethysmography in Term Small for Gestational Age and Appropriate for Gestational Age Neonates.

Background: Small for gestational age (SGA) neonates are prone to growth deficits in early life, which may be associated with later life metabolic abnormalities.

Objectives: To compare anthropometry and body composition using air-displacement plethysmography (ADP) in term SGA and appropriate for gestational age (AGA) neonates, and assess if sexual dimorphism existed in estimates of body composition.

Study Design: Cross-sectional analytical study.

Intraindividual double burden of malnutrition: The contribution of the infant gut microbiome.

The prevalence of the double burden of malnutrition in society is well known with the coexistence of undernutrition with an increase in overweight/obesity; this has been increasing globally with nutritional imbalances and infectious diseases being the major etiological factors. However, there is also the coexistence of inappropriate adiposity or metabolic dysfunction in an individual who appears currently undernourished by anthropometric standards (stunted or underweight); this is the intraindividual double burden of malnutrition. It could also occur in temporal sequence, as anthropometric overweight in an individual who has previously endured childhood under-nutrition.

The compressive, shear, biochemical, and histological characteristics of diabetic and non-diabetic plantar skin are minimally different.

Diabetes is associated with lower limb co-morbidities, including ulceration and subsequent amputation. As a systemic disease, diabetes affects the microstructure of soft tissues, and material microstructural changes are known to affect the macroscale mechanics. However, the associations between diabetes-related disruptions to essential microstructural components and mechanical changes in plantar skin with diabetes has not been thoroughly characterized.

The association between mechanical and biochemical/histological characteristics in diabetic and non-diabetic plantar soft tissue.

Diabetes, and the subsequent complication of lower limb ulcers leading to potential amputation, remains an important health care problem in United States, even with declining amputation rates. It has been well documented that diabetes can alter the mechanical properties (i.e.

Hyperelastic compressive mechanical properties of the subcalcaneal soft tissue: An inverse finite element analysis.

Finite element (FE) foot models can provide insight into soft tissue internal stresses and allow researchers to effectively conduct parametric analyses. Accurate plantar soft tissue material properties are essential for the development of FE foot models for clinical interventions. The aim of this study was to identify the first-order and second-order Ogden hyperelastic material properties of the subcalcaneal fat using an inverse FE analysis.

The effect of prior compression tests on the plantar soft tissue compressive and shear properties.

Changes in the shear plantar soft tissue properties with diabetes are believed to play a role in plantar ulceration, yet little is known about these properties. Our group recently conducted shear tests on specimens previously tested in compression to fully characterize the tissue under both these loading modes. However, previously tested specimens may not necessarily provide representative mechanical properties as prior testing may have altered the tissue to an unknown extent.

The shear mechanical properties of diabetic and non-diabetic plantar soft tissue.

Changes in the plantar soft tissue shear properties may contribute to ulceration in diabetic patients, however, little is known about these shear parameters. This study examines the elastic and viscoelastic shear behavior of both diabetic and non-diabetic plantar tissue. Previously compression tested plantar tissue specimens (n=54) at six relevant plantar locations (hallux, first, third, and fifth metatarsal heads, lateral midfoot, and calcaneus) from four cadaveric diabetic feet and five non-diabetic feet were utilized.

The quasi-linear viscoelastic properties of diabetic and non-diabetic plantar soft tissue.

The purpose of this study was to characterize the viscoelastic behavior of diabetic and non-diabetic plantar soft tissue at six ulcer-prone/load-bearing locations beneath the foot to determine any changes that may play a role in diabetic ulcer formation and subsequent amputation in this predisposed population. Four older diabetic and four control fresh frozen cadaveric feet were each dissected to isolate plantar tissue specimens from the hallux, first, third, and fifth metatarsals, lateral midfoot, and calcaneus. Stress relaxation experiments were used to quantify the viscoelastic tissue properties by fitting the data to the quasi-linear viscoelastic (QLV) theory using two methods, a traditional frequency-insensitive approach and an indirect frequency-sensitive approach, and by measuring several additional parameters from the raw data including the rate and amount of overall relaxation.

The effect of target strain error on plantar tissue stress.

Accurate quantification of soft tissue properties, specifically the stress relaxation behavior of viscoelastic tissues such as plantar tissue, requires precise testing under physiologically relevant loading. However, limitations of testing equipment often result in target strain errors that can contribute to large stress errors and confound comparative results to an unknown extent. Previous investigations have modeled this artifact, but they have been unable to obtain empirical data to validate their models.

The compressive mechanical properties of diabetic and non-diabetic plantar soft tissue.

Diabetic subjects are at an increased risk of developing plantar ulcers. Knowledge of the physiologic compressive properties of the plantar soft tissue is critical to understanding the possible mechanisms of ulcer formation and improving treatment options. The purpose of this study was to determine the compressive mechanical properties of the plantar soft tissue in both diabetic and non-diabetic specimens from six relevant locations beneath the foot, namely the hallux (big toe), first, third, and fifth metatarsal heads, lateral midfoot, and calcaneus (heel).

Characterization of forces on the sternal midline following median sternotomy in a porcine model.

The development of more effective fixation devices for reapproximating and immobilizing the sternum after open-heart surgery is limited by current methods for evaluating these devices. In particular, precise emulation of in vivo sternal loading has not been achieved in controlled model systems. The present study is an initial effort to determine the in vivo loading parameters needed to improve current in vitro and in silico (computational) models.

A mechanical study of rigid plate configurations for sternal fixation.

Rigid metal plates are a promising alternative to wires for reapproximating the sternum after open-heart surgery due to their potential ability to reduce motion at the wound site and thereby reduce the likelihood of post-operative healing complications. Despite initial clinical success, the use of plates has been limited, in part, by insufficient knowledge about their most effective placement. This study compares the ability of five plate configurations to provide stable closure by limiting sternal separation.

In vitro comparison of wire and plate fixation for midline sternotomies.

Background: The incidence of severe sternal wound complications in high-risk cardiac patients presents a significant need for more stabile sternal fixation techniques after median sternotomy procedures. Rigid metal plates, a potential alternative to wire fixation, are thought to promote faster sternal healing by reducing motion at the wound site. The goal of this study was to compare the stability provided by commercially available sternal plates with standard wires using an in vitro model.