Physiology Commons^™

The Relationship Between Dorsiflexion Range Of Motion And Knee Kinematics In A Land-And-Jump Task, Nate Brookreson

EWU Masters Thesis Collection

The study examined the relationship between weight-bearing and non weight-bearing dorsiflexion range of motion and frontal knee kinematics at initial ground contact and maximal knee flexion in a land-and-jump task. Thirteen male participants (age = 23 + 2.35 y, height = 181.4 + 5.68 cm, mass = 84.5 + 17.2 kg) proficient in landing and jumping techniques and free from lower limb injury participated in the study. Measurement of ankle range of motion was conducted utilizing non weight-bearing and weight-bearing positions prior to participating in the land-and jump task. During the jump, a 10-camera Vicon 3D Motion Analysis System captured …

Over-Expressed Copper/Zinc Superoxide Dismutase Localizes To Mitochondria In Neurons Inhibiting The Angiotensin Ii-Mediated Increase In Mitochondrial Superoxide, Shumin Li, Adam J. Case, Rui-Fang Yang, Harold D. Schultz, Matthew C. Zimmerman

Journal Articles: Cellular & Integrative Physiology

Angiotensin II (AngII) is the main effector peptide of the renin-angiotensin system (RAS), and contributes to the pathogenesis of cardiovascular disease by exerting its effects on an array of different cell types, including central neurons. AngII intra-neuronal signaling is mediated, at least in part, by reactive oxygen species, particularly superoxide (O2 (•-)). Recently, it has been discovered that mitochondria are a major subcellular source of AngII-induced O2 (•-). We have previously reported that over-expression of manganese superoxide dismutase (MnSOD), a mitochondrial matrix-localized O2 (•-) scavenging enzyme, inhibits AngII intra-neuronal signaling. Interestingly, over-expression of copper/zinc superoxide dismutase (CuZnSOD), which is believed …

The Cross Education Of Neuromuscular Economy, Kyle Beyer

Electronic Theses and Dissertations

Cross education is the phenomenon by which the untrained limb will experience a gain in strength following a unilateral resistance training program. However, little is known as to the underlying adaptation occurring in the untrained limb. Purpose: To examine the effect of dynamic unilateral resistance training on the strength and neuromuscular adaptations of both the trained and untrained legs. Methods: Eight previously untrained males (22.38±2.92 y, 1.73±0.08 m, 75.26±14.53 kg) completed a four-week unilateral resistance training program, while another eight untrained males (24.00±4.57 y, 1.84±0.05 m, 94.21±16.14 kg) served as controls. Isometric leg extension strength, leg press 1 repetition maximum …

Isokinetic Fatigue Characteristics For The Leg Extensors Versus Flexors, Elias M. Carrillo, Matt S. Stock, Jacob A. Mota, Kendra D. Olinghouse, Alexander S. Drusch, Brennan J. Thompson

Kinesiology and Health Science Faculty Publications

Maximal isokinetic muscle actions are often used in research studies to examine fatigability and even estimate muscle fiber-type. However, the majority of previous investigations have examined these topics for the leg extensors (i.e., quadriceps), and we are unaware of investigations that have specifically assessed the fatigue characteristics for the flexors (i.e., hamstrings). The purpose of this study was to compare the percent decline values for the leg extensors versus flexors for 50 and 100 repeated, maximal concentric isokinetic muscle actions. Fifteen healthy men (mean ± SD age = 23 ± 3 years; body mass = 94.1 ± 11.9 kg) with …

Introduction To Fourth Special Issue On Electroporation-Based Technologies And Treatments, Damijan Miklavčič, Lluis M. Mir, P. Thomas Vernier

Bioelectrics Publications

This fourth special electroporation-based technologies and treatments issue of the Journal of Membrane Biology contains reports on recent developments in the field of electroporation by participants in the 7th International Workshop and Postgraduate Course on electroporation based technologies and treatments (EBTT 2013) held in Ljubljana, November 17–23, 2013. The 65 participants included faculty members, invited lecturers, special guests, and young scientists, and students from 16 countries. In addition to lectures on the fundamentals, this year’s sessions included talks on microbial inactivation by pulsed electric fields, modeling of intracellular electroporation, electroporation in food processing, and electrotransfer-facilitated DNA vaccination.

The Effects Of Stress Hormones On Preferences For Acoustic Signals In Female Green Treefrogs (Hyla Cinerea) And Barking Treefrogs (Hyla Gratiosa), Anna Gabriell Davis

Electronic Theses and Dissertations

Ecological stressors (i.e., high predator density, low food availability) are often associated with increased variation in mate choice by females. The association between environmental stressors and variation in mate choice suggests that circulating stress hormones (i.e., glucocorticoids) may mediate such effects, but this idea remains largely unexplored. I examined how circulating glucocorticoids affect preferences for male advertisement calls in female green treefrogs, Hyla cinerea, and barking treefrogs, Hyla gratiosa. Specifically, I examined whether administration of corticosterone (CORT) decreases preferences for call rate and/or call duration - two acoustic features that are highly variable and characteristically under directional selection via mate …

Mitochondrial Dynamics: Exploring A Novel Target Against Myocardial Ischemia-Reperfusion Injury, Yi Dong

Wayne State University Dissertations

Mitochondrial fusion and fission, collectively termed mitochondrial dynamics, are among the core mechanisms responsible for maintaining mitochondrial health and functional integrity. Dynamin-related protein 1 (DRP1) is a key regulator of mitochondrial fission. Recent studies suggest that i) mitochondrial dynamics, particularly, mitochondrial fission, serves as a mediator of cell fate in the setting of ischemia-reperfusion (IR) injury, and, ii) inhibition of DRP1 and mitochondrial fission provides cardioprotection against IR injury. However, the precise role of DRP1 translocation to mitochondria in the pathogenesis of myocardial ischemia-reperfusion injury has not been established.

Using an established model of hypoxia-reoxygenation (HR) in cultured HL-1 cardiomyocytes, …

Muscle Metaboreflex Control Of Cardiovascular Function In Hypertension, Marty Daniel Spranger

Wayne State University Dissertations

Skeletal muscle ischemia during or immediately following exercise leads to the accumulation of metabolites (e.g., lactate, proton and diprotonated phosphate) which activate chemoreceptive afferents within the muscle leading to a reflex increase in sympathetic outflow generating substantial increases in mean arterial pressure (MAP), cardiac output (CO) and heart rate (HR) - termed the muscle metaboreflex. When the reflex is activated during submaximal dynamic exercise, the pressor response occurs via increased CO with no net peripheral vasoconstriction. When metaboreflex activation is sustained during the recovery from exercise (i.e., post-exercise muscle ischemia - (PEMI)), whereas MAP remains elevated for as long as …

The Nh2-Hypervariable Region Modulates The Binding Affinity Of Troponin T For Tropomyosin, Chinthaka Kaushalya Amarasinghe

Wayne State University Theses

The troponin complex plays a central role in the allosteric function of sarcomeric thin filaments by enacting conformational changes during the Ca2+-regulated contraction and relaxation of striated muscle. The troponin subunit T (TnT) has two binding sites for tropomyosin (Tm) and is responsible for anchoring the troponin complex to the thin filament. Although the C-terminal and middle regions of the TnT polypeptide chain are highly conserved among the three muscle type isoforms, the hypervariable N-terminal region has evolutionarily diverged significantly among isoforms. Previous studies have shown that the N-terminal variable region fine-tunes Ca2+ regulation of muscle contractility via modulation of …

Peri-Exercise Co-Ingestion Of Branched-Chain Amino Acids And Carbohydrate In Men Does Not Preferentially Augment Resistance Exercise-Induced Increases In Pi3k/Akt-Mtor Pathway Markers Indicative Of Muscle Protein Synthesis, Maria Pontes Ferreira, Rui Li, Matthew Cooke, Richard B. Kreider, Darryn S. Willoughby

Nutrition and Food Science Faculty Research Publications

The effects of a single bout of resistance exercise (RE) in conjunction with peri-exercise branched chain amino acid (BCAA) and carbohydrate (CHO) ingestion on skeletal muscle signaling markers indicative of muscle protein synthesis (MPS) were determined. It was hypothesized that CHO + BCAA would elicit a more profound effect on these signaling markers compared to CHO. Twenty-seven males were randomly assigned to CHO, CHO + BCAA, or placebo (PLC) groups. Four sets of leg presses and leg extensions were performed at 80% 1RM. Supplements were ingested 30 min and immediately prior to and after RE. Venous blood and muscle biopsy …

Greater Polar Moment Of Inertia At The Tibia In Athletes Who Develop Stress Fractures, Lee A. Weidauer, Teresa Binkley, Matthew Vukovich, Bonny Specker

Health and Nutritional Sciences Faculty Publications

Background: Several previous investigations have determined potential risk factors for stress fractures in athletes and military personnel.
Purpose: To determine factors associated with the development of stress fractures in female athletes.
Study Design: Case-control study; Level of evidence, 3.
Methods: A total of 88 female athletes (cross-country, n ¼ 29; soccer, n ¼ 15; swimming, n ¼ 9; track and field, n ¼ 14; volleyball, n ¼ 12; and basketball, n ¼ 9) aged 18 to 24 years were recruited to participate in a longitudinal bone study and had their left distal tibia at the 4%, 20%, and 66% sites …

Haploinsufficiency Of Cardiac Myosin Binding Protein-C In The Development Of Hypertrophic Cardiomyopathy, David Barefield

Dissertations

Heart Failure is one of the leading causes of morbidity and mortality in the human population and represents a common endpoint for several diseases including inherited cardiomyopathies. Hypertrophic Cardiomyopathy (HCM) is characterized by left ventricular wall thickening, diastolic dysfunction, and sarcomere disarray. Mutations in sarcomeric protein encoding genes have been established as causative for HCM.

The gene MYBPC3, encoding cardiac myosin binding protein-C (cMyBP-C), is the second most commonly mutated gene in HCM cases. As a majority of these mutations have been determined to result in a null allele which does not produce any protein, it is thought that haploinsufficiency …

Endocrine And Contralateral Muscle Responses To Short-Term Unilateral Resistance Training, Carleigh Boone

Electronic Theses and Dissertations

PURPOSE: The purpose of this study was to examine the effects of short-term lower body unilateral resistance training on hormonal, muscle morphological, and performance measures in young men. METHODS: Seventeen healthy, untrained young men (Age: 22.8 ± 3.7 y; BMI: 26.5 ± 4.9 kg/m2) were randomly assigned to one of two groups (UT: 22.9 ± 4.6 y, 25.3 ± 4.2 kg/m2; CON: 24.0 ± 4.6 y, 27.7 ± 5.1 kg/m2). Resistance training consisted of 4 weeks of unilateral lower body and bilateral upper body exercises on 3 days per week. Each training session entailed unilateral countermovement jumps (3 × 8), …

The Effect Of Moderate Altitude On High Intensity Running Performance During A Game With Collegiate Female Soccer Players, Jonathan Bohner

Electronic Theses and Dissertations

Competition often requires teams that reside at sea level to compete against opponents whose residence is at a moderate altitude. This may pose a potential competitive disadvantage considering that moderate altitude may cause decrements in VO2max, distance covered, and time to exhaustion in endurance athletes. The purpose of this study was to examine the effect of altitude on game performance measures. Six NCAA Division I female soccer players (20.33 ± 1.21 y; 168 ± 6.45 cm; 62.5 ± 6.03 kg) were retrospectively examined. Comparisons were made between two competitions that were played at sea level (SL) within two weeks of …

Renal Humoral, Genetic And Genomic Mechanisms Underlying Spontaneous Hypertension, Jason A. Collett

Theses and Dissertations--Biology

In spite of significant progress in our knowledge of mechanisms that control blood pressure, our understanding of the pathogenesis of hypertension, its genetics, and population efforts to control blood pressure, hypertension remains the leading risk factor for mortality worldwide. It’s estimated that 1 out of every 3 adults has hypertension. Hypertension is a major risk factor for cardiovascular disease and stroke, and is considered a primary or contributing cause of death to more than 2.4 million US deaths each year. Although spontaneous hypertension has been the subject of substantial research, many critical questions remain unanswered.

To investigate mechanisms underlying spontaneous …

Trpa1 Channels In Cochlear Supporting Cells Regulate Hearing Sensitivity After Noise Exposure, Alejandra C. Velez-Ortega

Theses and Dissertations--Physiology

TRPA1 channels are sensors for noxious stimuli in a subset of nociceptive neurons. TRPA1 channels are also expressed in cells of the mammalian inner ear, but their function in this tissue remains unknown given that Trpa1^–/– mice exhibit normal hearing, balance and sensory mechanotransduction. Here we show that non-sensory (supporting) cells of the hearing organ in the cochlea detect tissue damage via the activation of TRPA1 channels and subsequently modulate cochlear amplification through active cellshape changes.

We found that cochlear supporting cells of wild type but not Trpa1^–/– mice generate inward currents and robust long-lasting Ca²⁺ responses …

Basic Features Of A Cell Electroporation Model: Illustrative Behavior For Two Very Different Pulses, Reuben S. Son, Kyle C. Smith, Thiruvallur R. Gowrishankar, P. Thomas Vernier, James C. Weaver

Bioelectrics Publications

Science increasingly involves complex modeling. Here we describe a model for cell electroporation in which membrane properties are dynamically modified by poration. Spatial scales range from cell membrane thickness (5 nm) to a typical mammalian cell radius (10 μm), and can be used with idealized and experimental pulse waveforms. The model consists of traditional passive components and additional active components representing nonequilibrium processes. Model responses include measurable quantities: transmembrane voltage, membrane electrical conductance, and solute transport rates and amounts for the representative "long" and "short" pulses. The long pulse-1.5 kV/cm, 100 μs-evolves two pore subpopulations with a valley at ~5 …

An Analysis Of Abnormal Electrocardiograms In First And Second Year Medical School Students, Molly Anne Kalish

PCOM Biomedical Studies Student Scholarship

The high stress level placed upon medical school students, particularly during their first and second didactic years, may have a negative effect on their health. Although surveys and subjective questionnaires have been used to evaluate the effects medical school has upon a student’s cardiovascular health, there has been little clinical data obtained to confirm this notion. The aim of this longitudinal study was to demonstrate whether any abnormal cardiovascular parameters, specifically QTc wave interval, cardiac axis vector and blood pressure abnormalities, could be documented to occur in two different classes of medical students during their first two years. Such information …

Β-Amyloid Deposition Is Shifted To The Vasculature And Memory Impairment Is Exacerbated When Hyperhomocysteinemia Is Induced In App/Ps1 Transgenic Mice, Tiffany L. Sudduth, Erica M. Weekman, Holly M. Brothers, Kaitlyn Braun, Donna M. Wilcock

Physiology Faculty Publications

INTRODUCTION: Vascular dementia is the second most common cause of dementia after Alzheimer's disease (AD). In addition, it is estimated that almost half of all AD patients have significant cerebrovascular disease comorbid with their AD pathology. We hypothesized that cerebrovascular disease significantly impacts AD pathological progression.

METHODS: We used a dietary model of cerebrovascular disease that relies on the induction of hyperhomocysteinemia (HHcy). HHcy is a significant clinical risk factor for stroke, cardiovascular disease and type 2 diabetes. In the present study, we induced HHcy in APP/PS1 transgenic mice.

RESULTS: While total β-amyloid (Aβ) load is unchanged across groups, Congophilic …

Transmural Heterogeneity Of Cellular Level Cardiac Contractile Properties In Aging And Heart Failure, Premi Haynes

Theses and Dissertations--Physiology

The left ventricle of the heart relaxes when it fills with blood and contracts to eject blood into circulation to meet the body’s metabolic demands. Dysfunction in either relaxation or contraction of the left ventricle can lead to heart failure. Transmural heterogeneity is thought to contribute to normal ventricular wall motion but it is not well understood how transmural modifications affect the failing left ventricle. The overall hypothesis of this dissertation is that normal left ventricles exhibit transmural heterogeneity in cellular level contractile properties and with aging and heart failure there are region-specific changes in cellular level contractile mechanisms.

Age …