Physiology Commons^™

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 …

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.

Evaluation Of The Physiological Effects Of Reduced Hydroxocobalamin On Acute Carbon Monoxide Toxicity, Alden Newcomb

Theses and Dissertations

Carbon monoxide (CO) poisoning represents a global health threat responsible for hundreds of thousands of hospital visits and tens of thousands of deaths annually. Oxygen therapy is the only current approved treatment for CO poisoning. Previous work published in the 1970’s and research conducted in the VCURES lab group has indicated that a reduced form of vitamin B12, hydroxocobalamin (B12r), can potentially serve as an antidote for CO poisoning by converting CO bound to hemoglobin to carbon dioxide (CO2) and mitigating the deleterious neurological effects of CO poisoning. For the first time in documented literature we successfully used a Clark-type …

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 …

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 …

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 …

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 …

The Effects Of Strength Training On Isometric Force Production Symmetry In Recreationally Trained Males, Caleb D. Bazyler, Christopher A. Bailey, Chieh-Ying Chiang, Kimitake Sato, Michael H. Stone

ETSU Faculty Works

Objectives: The purpose of this investigation was to determine what effect a bilateral strength training regimen has on isometric force production symmetry and if changes in force production symmetry can be accounted for by differences in pre-intervention strength levels. Design: Sixteen recreationally trained males (1-RM squat: 146.8 ± 23.0 kg.) were assigned to two groups for the 7-week training intervention: strong (S) and weak (W) based on pre-training squat isometric peak force allometrically scaled (IPFa) at 120° knee angle. Methods: Subjects completed a 7-week training intervention following a block-periodized model and were tested on measures of dynamic (1RM squat) and …

The Relationship Of Force Production Asymmetry And Performance In Athletes Of Different Strength Levels, Christopher A. Bailey, Caleb D. Bazyler, Chieh-Ying Chiang, Kimitake Sato, Michael H. Stone

ETSU Faculty Works

The purpose of this study was to evaluate the relationship between force production asymmetry and performance of athletes with differing strength levels in males and females. Collegiate athletes (n=129) from various sports were ranked according to isometric mid-thigh pull peak force and the top (‘strong’) and bottom (‘weak’) 25% were used for analysis. Symmetry index (SI) scores were calculated and correlated with their respective force-time characteristics using bivariate correlations. For the weaker males, several negative moderate correlations were observed; however, no statistically significant correlations were observed for the females in either group. These findings indicate that force production asymmetry is …

Effects Of A Ten Week Barbell Deadlift Training Program On Vertical Jump Height In College-Aged Women, Kendra D. Olinghouse, Matt S. Stock, Jacob A. Mota, Elias M. Carrillo, Ibrahim K. Munayer, Jocarol E. Shields, Micheal J. Luera, Brennan J. Thompson

Kinesiology and Health Science Faculty Publications

The barbell deadlift is a large muscle mass exercise that primarily involves extension at the hip and knee joints. Although it is often incorporated into strength training programs with a variety of other exercises (e.g., back squat), no previous studies have examined the effects of deadlift training on strength or power adaptations. The purpose of this investigation was to examine the effects of a ten week barbell deadlift training program on vertical jump height in previously untrained women. Twenty-eight women (mean ± SD age = 22 ± 2 years) were randomly assigned to either the training group (n = 17) …

Relationships Among Maximal And Explosive Strength Production Of The Leg Extensors And Vertical Jump Peak Power Output In Female Youth Volleyball Athletes, Alexander S. Drusch, Jacob A. Mota, Kendra D. Olinghouse, Matt S. Stock, Brennan J. Thompson

Kinesiology and Health Science Faculty Publications

Architectural and physical performance measurements are commonly implemented to identify various physical capacities in many populations. However, previous research has suggested architectural measures, notably in the leg extensors, are ineffective predictors of vertical jumping (VJ) performance. Given the functional relevance of rapid strength development on explosive dynamic tasks, further research is warranted examining, a) the presence of associations of maximal (e.g., peak torque; PT) and, in particular, explosive (e.g., rate of torque development; RTD) strength-related characteristics with jumping performance in the leg extensors, and b) the extent to which PT and RTD either uniquely, or synergistically contribute to VJ performance. …

Effects Of Electrical Pulse Stimulation On In Vitro Measurement Of Mitochondrial Content And Lipid In Human Myotubes, Daniel Alberto Conde

Open Access Theses & Dissertations

It has been previously shown that human myotubes retain certain in vivo characteristics of the donors. Furthermore, we have shown that Electrical pulse stimulation (EPS), an in vitro exercise mimetic, increases mitochondrial and lipid content in cultured human myotubes after 24 hr. of stimulation. Purpose: We aimed to examine the EPS induced adaptations to lipid, mitochondrial, and Glucose transporter 4 (GLUT4) content using human myotubes. Methods: EPS was applied to myotubes for 60 min (bipolar pulses of 100 Hz, 30V, every 5 seconds), 24 hr. or 48 hr. (single bipolar pulses of 1 Hz for 2 ms; 30V) and were …