Medicine and Health Sciences Commons^™

Characterization Of Nrk2b Overexpression In A Transgenic Zebrafish Congenital Muscular Dystrophy Model, Anna Burgess

Honors College

Everyday movement, whether sitting or running a marathon, exerts stressful forces on myotendinous junctions (MTJs). As the sites which skeletal muscle fibers anchor to surrounding extracellular matrix (ECM) material of tendon, MTJs need to maintain homeostasis under stress for muscle to function normally. Human congenital muscular dystrophies (CMDs) are a heterogeneous group of diseases that disrupt muscle homeostasis, are severely debilitating, and currently have no cure. In many CMDs, genetic mutations effect cell adhesion complexes located at the MTJ. The adherence of muscle fibers’ cytoskeleton to the extracellular matrix (ECM) is weakened when these complexes as compromised. Many genes resulting …

The Role Of Rate Of Force Development On Vertical Jump Performance, Christopher Mclellan, Dale Lovell, Gregory Gass

Chris McLellan

The purpose of this study was to examine a) the relationship between rate of force development (RFD) and vertical jump (VJ) performance during a counter movement jump (CMJ), and b) the reliability of RFD recorded during the CMJ and squat jump (SJ) forms of the VJ. Twenty-three physically active men aged 23 ± 3.9 years participated in the study. Subjects completed 3 unloaded CMJ and 3 unloaded SJ in random order on a force plate. The RFD was measured during CMJ and SJ movements with vertical jump displacement (VJD) measured simultaneously during the CMJ only. Subjects incorporated arm swing to …

A Comparison Of Asynchronous And Synchronous Arm Cranking During The Wingate Test, Dale Lovell, Dale Mason, Elias Delphinus, Christopher Mclellan

Chris McLellan

Purpose: The aim of this study was to compare asynchronous (ASY) arm cranking (cranks at 180° relative to each other) with synchronous (SYN) arm cranking (parallel crank setting) during the 30 s Wingate anaerobic test.

Methods: Thirty-two physically active men (aged 22.1 ± 2.4 y) completed two Wingate tests (one ASY and one SYN) separated by 4 d in a randomized counterbalanced order. The Wingate tests were completed on a modified electromagnetically braked cycle ergometer. Performance measures assessed during the two tests include peak power, mean power, minimum power, time to peak power, rate to fatigue and maximum …

Sarcopenia, Obesity, And Natural Killer Cell Immune Senescence In Aging: Altered Cytokine Levels As A Common Mechanism, Charles T. Lutz, Lebris S. Quinn

Pathology and Laboratory Medicine Faculty Publications

Human aging is characterized by both physical and physiological frailty. A key feature of frailty, sarcopenia is the age-associated decline in skeletal muscle mass, strength, and endurance that characterize even the healthy elderly. Increases in adiposity, particularly in visceral adipose tissue, are almost universal in aging individuals and can contribute to sarcopenia and insulin resistance by increasing levels of inflammatory cytokines known collectively as adipokines. Aging also is associated with declines in adaptive and innate immunity, known as immune senescence, which are risk factors for cancer and all-cause mortality. The cytokine interleukin-15 (IL-15) is highly expressed in skeletal muscle tissue …

In Ovo Serial Skeletal Muscle Diffusion Tractography Of The Developing Chick Embryo Using Dti: Feasibility And Correlation With Histology, Zien Zhou, Zachary Delproposto, Lianming Wu, Jianrong Xu, Jia Hua, Yan Zhou, Yongquan Ye, Zishu Zhang, Jiani Hu, E Mark Haacke

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Magnetic resonance imaging is a noninvasive method of evaluating embryonic development. Diffusion tensor imaging (DTI), based on the directional diffusivity of water molecules, is an established method of evaluating tissue structure. Yet embryonic motion degrades the in vivo acquisition of long-duration DTI. We used a dual-cooling technique to avoid motion artifact and aimed to investigate whether DTI can be used to monitor chick embryonic skeletal muscle development in ovo, and to investigate the correlation between quantitative DTI parameters fractional anisotropy (FA) and fiber length and quantitative histologic parameters fiber area percentage (FiberArea%) and limb length.

Results

From 84 …

Two Maximal Isometric Contractions Attenuate The Magnitude Of Eccentric Exercise-Induced Muscle Damage, Hsin-Lian Chen, Kazunori Nosaka, Alan Pearce, Trevor C Chen

Research outputs 2012

This study investigated whether maximal voluntary isometric contractions (MVC-ISO) would attenuate the magnitude of eccentric exercise-induced muscle damage. Young untrained men were placed into one of the two experimental groups or one control group (n = 13 per group). Subjects in the experimental groups performed either two or 10 MVC-ISO of the elbow flexors at a long muscle length (20° flexion) 2 days prior to 30 maximal isokinetic eccentric contractions of the elbow flexors. Subjects in the control group performed the eccentric contractions without MVC-ISO. No significant changes in maximal voluntary concentric contraction peak torque, peak torque angle, range of …

Effects Of Short-Term Training With Uncoupled Cranks In Trained Cyclists, Jack Burns, Jeremiah Peiffer, Chris Abbiss, Greig Watson, Angus Burnett, Paul Laursen

Research outputs 2012

Purpose: Manufacturers of uncoupled cycling cranks claim that their use will increase economy of motion and gross efficiency. Purportedly, this occurs by altering the muscle-recruitment patterns contributing to the resistive forces occurring during the recovery phase of the pedal stroke. Uncoupled cranks use an independentclutch design by which each leg cycles independently of the other (ie, the cranks are not fixed together). However, research examining the efficacy of training with uncoupled cranks is equivocal. The purpose of this study was to determine the effect of short-term training with uncoupled cranks on the performance-related variables economy of motion, gross efficiency, maximal …

The Hippo Pathway Member Yap Plays A Key Role In Influencing Fate Decisions In Muscle Satellite Cells, Robert Judson, Annie Tremblay, Paul Knopp, Robert White, Roby Urcia, Cosimo De Bari, Peter Zammit, Fernando Camargo, Henning Wackerhage

Research outputs 2012

Satellite cells are the resident stem cells of skeletal muscle. Mitotically quiescent in mature muscle, they can be activated to proliferate and generate myoblasts to supply further myonuclei to hypertrophying or regenerating muscle fibres, or self-renew to maintain the resident stem cell pool. Here, we identify the transcriptional co-factor Yap as a novel regulator of satellite cell fate decisions. Yap expression increases during satellite cell activation and Yap remains highly expressed until after the differentiation versus self-renewal decision is made. Constitutive expression of Yap maintains Pax7+ and MyoD+ satellite cells and satellite cell-derived myoblasts, promotes proliferation but prevents differentiation. In …

The Effect Of Liver X Receptor Α Deficiency In Skeletal Muscle On Lipid Content In Mice, Yishu Ding

All ETDs from UAB

Liver X receptors (LXRs) are important regulators of cholesterol, fatty acid, and glucose homeostasis. Many researchs focus on the liver, but tissue-specific roles of LXRs in other tissues remain elusive. Based on in vitro studies on cultured cells, the roles of LXRs in skeletal muscle have been proposed. Nevertheless, the in vivo roles of LXRs in skeletal muscle remain lacking. Skeletal muscle is an important insulin targeting tissue, which plays a key role in regulating insulin sensitivity. Abnormal lipid metabolism and homeostasis have been demonstrated to play a crucial role in the development of insulin resistance in skeletal muscle. To …