Physiology Commons^™

Pacing Of An Untrained 17-Year-Old Teenager In A Marathon Attempt, Beat Knechtle, Celina Knechtle, Thomas Rosemann, Pantelis Nikolaidis

International Journal of Exercise Science

International Journal of Exercise Science 11(6): 856-866, 2018. Although there has been increased scientific interest for physiological responses to endurance running and pacing, limited information exists for adolescents participating in endurance events. We are reporting the case of an untrained 17-year-old female teenager (body mass 50.6 kg, height 167 cm and body mass index 18.1 kg/m²) who intended to run a marathon within 6 hours without preparation. The young woman missed her goal by just 2 km. When the average running speed per hour was analysed, there was a major effect of race hour on running speed (p …

Myonuclear Domain Flexibility Challenges Rigid Assumptions On Satellite Cell Contribution To Skeletal Muscle Fiber Hypertrophy, Kevin A. Murach, Davis A. Englund, Esther E. Dupont-Versteegden, John J. Mccarthy, Charlotte A. Peterson

Center for Muscle Biology Faculty Publications

Satellite cell-mediated myonuclear accretion is thought to be required for skeletal muscle fiber hypertrophy, and even drive hypertrophy by preceding growth. Recent studies in humans and rodents provide evidence that challenge this axiom. Specifically, Type 2 muscle fibers reliably demonstrate a substantial capacity to hypertrophy in the absence of myonuclear accretion, challenging the notion of a tightly regulated myonuclear domain (i.e., area that each myonucleus transcriptionally governs). In fact, a “myonuclear domain ceiling”, or upper limit of transcriptional output per nucleus to support hypertrophy, has yet to be identified. Satellite cells respond to muscle damage, and also play an important …

Transcriptional Profiling Reveals Extraordinary Diversity Among Skeletal Muscle Tissues, Erin E. Terry, Xiping Zhang, Christy Hoffmann, Laura D. Hughes, Scott A. Lewis, Jiajia Li, Matthew J. Wallace, Lance A. Riley, Collin M. Douglas, Miguel A. Gutierrez-Monreal, Nicholas F. Lahens, Ming C. Gong, Francisco H. Andrade, Karyn A. Esser, Michael E. Hughes

Physiology Faculty Publications

Skeletal muscle comprises a family of diverse tissues with highly specialized functions. Many acquired diseases, including HIV and COPD, affect specific muscles while sparing others. Even monogenic muscular dystrophies selectively affect certain muscle groups. These observations suggest that factors intrinsic to muscle tissues influence their resistance to disease. Nevertheless, most studies have not addressed transcriptional diversity among skeletal muscles. Here we use RNAseq to profile mRNA expression in skeletal, smooth, and cardiac muscle tissues from mice and rats. Our data set, MuscleDB, reveals extensive transcriptional diversity, with greater than 50% of transcripts differentially expressed among skeletal muscle tissues. We detect …

Identifying A Test To Monitor Weightlifting Performance In Competitive Male And Female Weightlifters, S. Kyle Travis, Jacob R. Goodin, George K. Beckham, Caleb D. Bazyler

ETSU Faculty Works

Monitoring tests are commonly used to assess weightlifter’s preparedness for competition. Although various monitoring tests have been used, it is not clear which test is the strongest indicator of weightlifting performance. Therefore, the purpose of this study was to (1) determine the relationships between vertical jump, isometric mid-thigh pull (IMTP) and weightlifting performance; and (2) compare vertical jumps to IMTP as monitoring tests of weightlifting performance in a large cohort of male and female weightlifters. Methods: Fifty-two competitive weightlifters (31 males, 21 females) participated in squat and countermovement jump testing (SJ, CMJ), and IMTP testing performed on force plates. All …

Visualizing Mutation-Specific Differences In The Trafficking-Deficient Phenotype Of Kv11.1 Proteins Linked To Long Qt Syndrome Type 2, Allison R. Hall, Corey L. Anderson, Jennifer L. Smith, Tooraj Mirshahi, Samy-Claude Elayi, Craig T. January, Brian P. Delisle

Physiology Faculty Publications

KCNH2 encodes the Kv11.1 α-subunit that underlies the rapidly activating delayed-rectifier K⁺ current in the heart. Loss-of-function KCNH2 mutations cause long QT syndrome type 2 (LQT2), and most LQT2-linked missense mutations inhibit the trafficking of Kv11.1 channel protein to the cell surface membrane. Several trafficking-deficient LQT2 mutations (e.g., G601S) generate Kv11.1 proteins that are sequestered in a microtubule-dependent quality control (QC) compartment in the transitional endoplasmic reticulum (ER). We tested the hypothesis that the QC mechanisms that regulate LQT2-linked Kv11.1 protein trafficking are mutation-specific. Confocal imaging analyses of HEK293 cells stably expressing the trafficking-deficient LQT2 mutation F805C showed that, …

Trf1 Mutations As A Mechanism For Telomere Length Maintenance In Cancer, Collin Sanderson, Jonathan Alder

Journal of Undergraduate Research

Telomeres are repetitive DNA sequences found on the ends of chromosomes that serve to protect the genes contained within each chromosome. As a cell replicates, its telomeres shorten, eventually triggering cellular senescence or death. This serves as a tumor suppressive mechanism by limiting the proliferation of cells. All cancers must overcome this growth limitation by acquiring mutations that permit telomere elongation. Most cancers achieve this by acquiring activating-mutations in an enzyme known as telomerase. Some cancers do not express telomerase, and maintain their telomeres by other means including a mechanism called “alternative lengthening of telomeres” (ALT). However, there exists a …

Space Operations In The Suborbital Space Flight Simulator And Mission Control Center: Lessons Learned With Xcor Lynx, Pedro Llanos, Christopher Nguyen, David Williams, Kim O. Chambers, Erik Seedhouse, Robert Davidson

Journal of Aviation/Aerospace Education & Research

This study was conducted to better understand the performance of the XCOR Lynx vehicle. Because the Lynx development was halted, the best knowledge of vehicle dynamics can only be found through simulator flights. X-Plane 10 was chosen for its robust applications and accurate portrayal of dynamics on a vehicle in flight. The Suborbital Space Flight Simulator (SSFS) and Mission Control Center (MCC) were brought to the Applied Aviation Sciences department in fall 2015 at Embry-Riddle Aeronautical University, Daytona Beach campus. This academic and research tool is a department asset capable of providing multiple fields of data about suborbital simulated flights. …

Thermoregulatory Dysfunction In Multiple Sclerosis, Dustin R. Allen

Applied Physiology and Wellness Theses and Dissertations

Multiple sclerosis (MS) is a progressive neurological disease of the central nervous system (CNS) affecting an estimated 2.3 million people worldwide. Marked by lesions in the brain and spinal cord, MS leads to conduction abnormalities in the CNS. Evidence suggests ~60% of individuals with MS experience temporary worsening of their symptoms upon exposure to heat. Adding complexity, observational evidence suggests these individuals exhibit reduced thermoregulatory responses in upon increases in core temperature. Consequently, these individuals face a vicious cycle of heat sensitivity and thermoregulatory dysfunction, substantially impacting their quality of life. With this in mind, our lab is dedicated to …

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …

Effects Of Prior Fasting On Fat Oxidation During Resistance Exercise, Kendall Frawley, Gabrielle Greenwald, Rebecca R. Rogers, John K. Petrella, Mallory R. Marshall

International Journal of Exercise Science

International Journal of Exercise Science 11(2): 827-833, 2018. Prior research has demonstrated that the percentage of fuel utilization contributed by CHO compared to fat rises with an increase in exercise intensity. The role of food intake prior to exercise has been well studied and fasting prior to exercise generally increases reliance on fat as fuel. However, data on the role of fasting prior to resistance exercise is limited. Therefore, the purpose of this study was to assess the effects of one bout of resistance training in a fasted state compared to ingestion of standardized meal on fat and carbohydrate utilization. …

Behavior Of Heart Rate Variability After 10 Repetitions Maximum Load Test For Lower Limbs, Estêvão R. Monteiro, Jefferson S. Novaes, Aline G. Fiuza, Eduardo Portugal, Felipe S. Triani, Leonardo Bigio, Rudson Santos, Alexandre Palma, Victor G. Corrêa Neto

International Journal of Exercise Science

International Journal of Exercise Science 11(6): 834-843, 2018. The purpose of this study was to analyze the acute heart rate variability behavior after 10 repetitions maximum load test for back squat, leg press, leg extension, and leg flexion in normotensive subjects. Eight recreationally trained women (age: 21.8 ± 2.2 yrs; height: 167.6 ± 6.3 cm; weight: 61.6 ± 10.1 kg) performed two 10 repetitions maximum testing days with 48-hours rest between each one. Heart rate variability was measured in baseline and postexercise (15-, 30-, 45-, and 60-minutes) for time and frequency domain. A significant difference was identified in RMSSD_{ms …}

Relative Handgrip Strength As A Simple Tool To Evaluate Impaired Heart Rate Recovery And A Low Chronotropic Index In Obese Older Women, Cristiane Rocha Da Silva, Dahan Da Cunha Nascimento, Ivo Sousa Neto, Ramires Tibana, Samuel Oliveira, Renato Valduga, Nayara Santos, Bruno Saraiva, Jonato Prestes, Jeffrey Willardson, Guilherme Borges Pereira

International Journal of Exercise Science

International Journal of Exercise Science 11(2): 844-855, 2018. The aim of the present study was to compare differences in heart rate response following a treadmill exercise test in elderly obese women categorized into groups based on relative handgrip strength. Eighty-eight obese elderly women who were between the ages of 60 and 87 participated in the study and were categorized and enrolled to one of two groups based on lower (< 1.51 m²) or higher (≥ 1.51 m²) relative handgrip strength, respectively. The heart rate recovery in the first and second minutes following the treadmill exercise test and the chronotropic index were compared between groups. The higher relative handgrip strength group presented a significantly higher peak heart rate during exercise and a quicker heart rate recovery following exercise versus the lower relative handgrip strength group (pp=0.059) toward a significantly greater chronotropic index in the higher versus the lower relative handgrip strength group. In conclusion, elderly women with greater relative handgrip strength also demonstrated a …

Systematic Pan-Cancer Analysis Of Somatic Allele Frequency., Liam Spurr, Muzi Li, Nawaf Alomran, Qianqian Zhang, Paula Restrepo, Mercedeh Movassagh, Chris Trenkov, Nerissa Tunnessen, Tatiyana Apanasovich, Keith A Crandall, Nathan Edwards, Anelia Horvath

Pharmacology and Physiology Faculty Publications

Imbalanced expression of somatic alleles in cancer can suggest functional and selective features, and can therefore indicate possible driving potential of the underlying genetic variants. To explore the correlation between allele frequency of somatic variants and total gene expression of their harboring gene, we used the unique data set of matched tumor and normal RNA and DNA sequencing data of 5523 distinct single nucleotide variants in 381 individuals across 10 cancer types obtained from The Cancer Genome Atlas (TCGA). We analyzed the allele frequency in the context of the variant and gene functional features and linked it with changes in …

Examining The Potential Role Of Gpr18 And Gpr119 In Learning And Memory, Brandon Anderson, James Kranewitter-Call, Dr. Jeffrey Edwards

Journal of Undergraduate Research

Many mental disorders plague our society. Dementia and Alzheimer’s disease have greatly impacted many victims and their families. Despite the seriousness and pervasiveness of Alzheimer’s, there is still no effective treatment for it nor the accompanying dementia. GPR18 and GPR119 are G-protein coupled receptors (GPRs) and have been identified in the central nervous system, but their functional role is unknown. Many successful drugs target GPR proteins, so examining these GPRs’ function in the brain could lead to potential targets leading to innovative medical advances.

Memory is dependent on a molecular process called synaptic plasticity. In synaptic plasticity, the strength of …

Effect Of Exercise And Hypoxia On Plasma Telomerase, Charli D. Aguilar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Telomerase reverse transcriptase (TERT) is the enzyme that adds telomeric sequences to the end of linear chromosomes. Exercise has shown to upregulate acutely leukocyte TERT after just 30 minutes of running on a treadmill at 80% of VO2max (Denham et al., 2016). Hypoxia inducible factor 1 (HIF-1) is also a mediator of TERT in in vitro (Nishi et al., 2004). Moderate acute exposure to hypoxia was associated with substantial increases in plasma TERT in a recent study on rats (Wang et al., 2014). The specific aim of the current study was to identify if acute hypoxia upregulates plasma TERT …

The Impact Of An External Load Of Football Equipment On Dynamic Balance As Assessed By The Modified Star Excursion Balance Test, Thomas J. Denehy, Timothy F. Marshall, Kim Spaccarotella, Walter Andzel

International Journal of Exercise Science

International Journal of Exercise Science 11(4): 797-805, 2018.Ankle sprains are common injuries, especially for football players, and may result in ankle instability, which can limit performance and increase injury risk. Ankle stability return to play criteria is often assessed under loaded conditions, even though previous research suggests loaded conditions affect dynamic balance. The purpose of this study was to evaluate dynamic balance under loaded conditions. A modified Star Excursion Balance Test (SEBT), incorporating anterior, posterior medial and posterior lateral reach directions under the loaded condition of NCAA Division III football equipment was evaluated. Thirty male collegiate football players completed …

Forward Genetic Screen To Identify Novel Genes Involved In Nhej Dna Repair, Taylor Brown, Dr. Jonathan Alder

Journal of Undergraduate Research

DNA contains all the information a cell needs to grow, divide, differentiate, and survive. It also dictates how and when a cell should die. DNA damage (particularly double strand breaks i.e. DSBs) may lead to cell death and/or disease. To circumvent DNA breaks, cells use various DNA repair mechanisms including non-homologous end joining (NHEJ). My ORCA research project focused on identifying novel genes involved in NHEJ. I did this by performing a forward genetic screen (FGS) that tested every known gene in the genome for involvement in NHEJ.

Disruption Of Neonatal Cardiomyocyte Physiology Following Exposure To Bisphenol-A., Manelle Ramadan, Meredith Sherman, Rafael Jaimes, Ashika Chaluvadi, Luther Swift, Nikki Gillum Posnack

Pharmacology and Physiology Faculty Publications

Bisphenol chemicals are commonly used in the manufacturing of polycarbonate plastics, polyvinyl chloride plastics, resins, and thermal printing applications. Humans are inadvertently exposed to bisphenols through contact with consumer products and/or medical devices. Recent reports have shown a link between bisphenol-a (BPA) exposure and adverse cardiovascular outcomes; although these studies have been limited to adult subjects and models. Since cardiac physiology differs significantly between the developing and adult heart, we aimed to assess the impact of BPA exposure on cardiac function, using a neonatal cardiomyocyte model. Neonatal rat ventricular myocytes were monitored to assess cell viability, spontaneous beating rate, beat …

Exotic Properties Of A Voltage-Gated Proton Channel From The Snail Helisoma Trivolvis, Sarah Thomas, Vladimir V. Cherny, Deri Morgan, Liana R. Artinian, Vincent Rehder, Susan M. E. Smith, Thomas E. Decoursey

Faculty Articles

Voltage-gated proton channels, HV1, were first reported in Helix aspersa snail neurons. These H+ channels open very rapidly, two to three orders of magnitude faster than mammalian HV1. Here we identify an HV1 gene in the snail Helisoma trivolvis and verify protein level expression by Western blotting of H. trivolvis brain lysate. Expressed in mammalian cells, HtHV1 currents in most respects resemble those described in other snails, including rapid activation, 476 times faster than hHV1 (human) at pHo 7, between 50 and 90 mV. In contrast to most HV1, activation of HtHV1 is exponential, suggesting first-order kinetics. However, the large …

Histidine168 Is Crucial For Δph-Dependent Gating Of The Human Voltage-Gated Proton Channel, Hhv1, Vladimir V. Cherny, Deri Morgan, Sarah Thomas, Susan M. E. Smith, Thomas E. Decoursey

Faculty Articles

We recently identified a voltage-gated proton channel gene in the snail Helisoma trivolvis, HtHV1, and determined its electrophysiological properties. Consistent with early studies of proton currents in snail neurons, HtHV1 opens rapidly, but it unexpectedly exhibits uniquely defective sensitivity to intracellular pH (pHi). The H+ conductance (gH)-V relationship in the voltage-gated proton channel (HV1) from other species shifts 40 mV when either pHi or pHo (extracellular pH) is changed by 1 unit. This property, called ΔpH-dependent gating, is crucial to the functions of HV1 in many species and in numerous human tissues. The HtHV1 channel exhibits normal pHo dependence but …