Musculoskeletal System Commons^™

Sex Differences In The Effects Of Cortisol On Muscle Characteristics: A Meta-Analysis, Natalie Bitetti

CMC Senior Theses

Background: Cortisol plays a central role in both muscle breakdown and growth. These effects are highly dependent on dose and interactions with other hormones. It is known that men and women show considerable differences in their muscle structure and physiology, which are largely driven by hormonal differences. Cortisol release patterns may also vary between the sexes, with current research showing considerable disagreement. The interplay between cortisol and muscle, two highly variable and sexually dimorphic factors, may prove to have different effects in males versus females.

Objective: This meta-analysis integrates existing research on sex differences in cortisol-muscle physiology with existing research …

Role Of Fat Content On The Structure And Function Of Human Skeletal Muscle, Joseph A. Gordon Iii

Doctoral Dissertations

Muscle size does not fully explain variations in muscle strength. Fat content has been implicated in muscle weakness, though this relationship remains unclear. The relationship between fat and strength may vary between scales (e.g., cellular, organ, and organism). The goal of this dissertation was to clarify the role of fat in the structure and function of muscle using in vitro and in vivo techniques across multiple scales in adults 21-45 years old. Study 1 tested the agreement of intramyocellular lipid (IMCL) content between oil red o (ORO) and magnetic resonance spectroscopy (MRS) techniques. These measures of IMCL were also compared …

A Single-Cell Atlas Of Bovine Skeletal Muscle Reveals Mechanisms Regulating Intramuscular Adipogenesis And Fibrogenesis, Leshan Wang, Peidong Gao, Chaoyag Li, Qianglin Liu, Zeyang Yao, Yuxia Li, Xujia Zhang, Jiangwen Sun, Constantine Simintiras, Matthew Welborn, Kenneth Mcmillin, Stephanie Oprescu, Shihuan Kuang, Xing Fu

Computer Science Faculty Publications

Background: Intramuscular fat (IMF) and intramuscular connective tissue (IMC) are often seen in human myopathies and are central to beef quality. The mechanisms regulating their accumulation remain poorly understood. Here, we explored the possibility of using beef cattle as a novel model for mechanistic studies of intramuscular adipogenesis and fibrogenesis.

Methods: Skeletal muscle single-cell RNAseq was performed on three cattle breeds, including Wagyu (high IMF), Brahman (abundant IMC but scarce IMF), and Wagyu/Brahman cross. Sophisticated bioinformatics analyses, including clustering analysis, gene set enrichment analyses, gene regulatory network construction, RNA velocity, pseudotime analysis, and cell-cell communication analysis, were performed to elucidate …

Mammalian And Invertebrate Models As Complementary Tools For Gaining Mechanistic Insight On Muscle Responses To Spaceflight, Amber M. Paul, Thomas Cahill, Henry Cope, Joseph J. Bass, Eliah G. Overbey, Rachel Gilbert

Publications

Bioinformatics approaches have proven useful in understanding biological responses to spaceflight. Spaceflight experiments remain resource intensive and rare. One outstanding issue is how to maximize scientific output from a limited number of omics datasets from traditional animal models including nematodes, fruit fly, and rodents. The utility of omics data from invertebrate models in anticipating mammalian responses to spaceflight has not been fully explored. Hence, we performed comparative analyses of transcriptomes of soleus and extensor digitorum longus (EDL) in mice that underwent 37 days of spaceflight. Results indicate shared stress responses and altered circadian rhythm. EDL showed more robust growth signals …

Simulation Of A Rat Muscle-Tendon Unit With Hill-Type Model Dynamics And The Study Of Viscoelasticity In A Collagen Molecule Via Molecular Dynamics, Veronica Siko

West Chester University Master’s Theses

The field of biological science has established that tendons transfer muscular forces to adjacent bones, but there is a dearth of information about the underlying physical principles of these interactions and how the property of viscoelasticity (displayed in tendons as a difference in mechanical response to stress with differing stretching rates) is encompassed in the collagen of tendons. This thesis details the results of concentric and eccentric contractions of the rat muscle-tendon unit (MTU) with and without viscoelasticity (concentric contraction requires active shortening of the muscle, while eccentric contraction requires active lengthening of the muscle) (Lovering & Brooks, 2014). Once …

Osteopontin Is Linked With Akt, Foxo1, And Myostatin In Skeletal Muscle Cells, Peter P. Nghiem, Joe N. Kornegay, Kitipong Uaesoontrachoon, Luca Bello, Ying Yin, Akanchha Kesari, Priya Mittal, Scott J. Schatzberg, Gina M. Many, Norman H. Lee, Eric P. Hoffman

All Faculty Scholarship for the College of the Sciences

Introduction: Osteopontin (OPN) polymorphisms are associated with muscle size and modify disease progression in Duchenne muscular dystrophy (DMD). We hypothesized that OPN may share a molecular network with myostatin (MSTN).

Methods: Studies were conducted in the golden retriever (GRMD) and mdx mouse models of DMD. Follow-up in-vitro studies were employed in myogenic cells and the mdx mouse treated with recombinant mouse (rm) or human (Hu) OPN protein.

Results: OPN was increased and MSTN was decreased and levels correlated inversely in GRMD hypertrophied muscle. RM-OPN treatment led to induced AKT1 and FoxO1 phosphorylation, microRNA-486 modulation, and decreased MSTN. An AKT1 inhibitor …

Effects Of Gait Speed Of Femoroacetabular Joint Forces, Joshua T. Weinhandl, Bobbie S. Irmisher, Zachary A. Sievert

Human Movement Sciences Faculty Publications

Alterations in hip joint loading have been associated with diseases such as arthritis and osteoporosis. Understanding the relationship between gait speed and hip joint loading in healthy hips may illuminate changes in gait mechanics as walking speed deviates from preferred. The purpose of this study was to quantify hip joint loading during the gait cycle and identify differences with varying speed using musculo skeletal modeling. Ten, healthy, physically active individuals performed walking trials at their preferred speed, 10% faster, and 10% slower. Kinematic, kinetic, and electromyographic data were collected and used to estimate hip joint force via a musculoskeletal model. …

The Development Of Skeletal Muscle In Young Horses: An Ultrasonography And Satellite Cell Approach, Emma K. Lavigne

Honors Scholar Theses

Muscle growth in young horses is characterized by an increase in muscle cross-sectional area, which can be accomplished through the activation and differentiation of satellite cells. Satellite cells can be stimulated or inhibited in response to different cytokines and growth factors and are key mediators of muscle hypertrophy and regeneration. The aim of this study was to investigate the growth of the longissimus dorsi (LD) muscle in horses under 5 years of age and to obtain preliminary data on satellite cell behavior in foals. The area, width, height, and subcutaneous fat were measured using ultrasonography at 6-month increments over the …

Segmental Musculoskeletal Examinations Using Dual-Energy X-Ray Absorptiometry (Dxa): Positioning And Analysis Considerations, Nicolas H. Hart, Sophia Nimphius, Tania Spiteri, Jodie L. Cochrane, Robert U. Newton

Research outputs 2014 to 2021

Musculoskeletal examinations provide informative and valuable quantitative insight into muscle and bone health. DXA is one mainstream tool used to accurately and reliably determine body composition components and bone mass characteristics in-vivo. Presently, whole body scan models separate the body into axial and appendicular regions, however there is a need for localised appendicular segmentation models to further examine regions of interest within the upper and lower extremities. Similarly, in-consistencies pertaining to patient positioning exist in the litera-ture which influence measurement precision and analysis out-comes highlighting a need for standardised procedure. This paper provides standardised and reproducible: 1) positioning and analysis …