Physiology Commons^™

The Effects Of Starvation Selection On Drosophila Melanogaster Life History And Development, Lauren A. Reynolds

UNLV Theses, Dissertations, Professional Papers, and Capstones

In nature, animals may endure periods of famine to complete their life cycles. Starvation stress will increase in populations as climates around the world change. To predict how populations may respond to such a stress, laboratory experimentation becomes essential. The evolutionary process of adaptation, its innovations and their trade-offs, can be studied in populations experiencing starvation stress. For this purpose outbred populations ofDrosophila melanogasterwere selected for starvation resistance in the laboratory.

After 60+ generations of starvation selection the starvation-selected flies have gone from surviving 2-3 days without food to 12-14 days without food. How this amazing feat of resistance is …

Nuclear Localization Of Cpi-17, A Protein Phosphatase-1 Inhibitor Protein, Affects Histone H3 Phosphorylation And Corresponds To Proliferation Of Cancer And Smooth Muscle Cells., Masumi Eto, Jason A Kirkbride, Rishika Chugh, Nana Kofi Karikari, Jee In Kim

Department of Molecular Physiology and Biophysics Faculty Papers

CPI-17 (C-kinase-activated protein phosphatase-1 (PP1) inhibitor, 17kDa) is a cytoplasmic protein predominantly expressed in mature smooth muscle (SM) that regulates the myosin-associated PP1 holoenzyme (MLCP). Here, we show CPI-17 expression in proliferating cells, such as pancreatic cancer and hyperplastic SM cells. Immunofluorescence showed that CPI-17 was concentrated in nuclei of human pancreatic cancer (Panc1) cells. Nuclear accumulation of CPI-17 was also detected in the proliferating vascular SM cell culture and cells at neointima of rat vascular injury model. The N-terminal 21-residue tail domain of CPI-17 was necessary for the nuclear localization. Phospho-mimetic Asp-substitution of CPI-17 at Ser12 attenuated the nuclear …

The Effects Of Tarsh Overexpression On Lung Carcinomas, Young Kim

Theses and Dissertations

Lung cancer arises from epithelial cells that line the air passages of the lungs. It is the second most common malignancy in the United States; trends suggest that over 228,000 new patients will be diagnosed with lung cancer in 2013. Due to the fact that lung cancer is highly aggressive, it has proven difficult to control. The 5-year survival rate has been shown to be only 15.9%, despite the advances made in terms of diagnosis and treatment. Therefore, we are faced with the problem of finding more effective methods that allow for an earlier diagnosis and the improved treatment of …

The Inflammasome In Acute Myocarditis, Harsha Kannan

Theses and Dissertations

Acute myocarditis is an acute inflammatory syndrome characterized by myocardial damage and dysfunction often due to a viral infection followed by a variable development over time. There are currently no specific treatments and standard treatments for heart failure are generally applied. The inflammasome is a recently identified macromolecular structure that occupies a central role in the amplification of the inflammatory response and promotion of cell death during acute and chronic infections. We hypothesized the formation of the inflammasome in acute myocarditis. To investigate, samples of patients were collected from the Cardiomyopathy Registry in Trieste, with 12 cases of biopsy-proven myocarditis …

Divergent Protein Motifs Direct Ef-P Mediated Translational Regulation In Salmonella And Escherichia Coli, Steven J. Hersch, Mengchi Wang, S. Betty Zou, Kyung-Mee Moon, Leonard J. Foster, Michael Ibba, William Wiley Navarre

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a universally conserved bacterial translation factor homologous to eukaryotic/archaeal initiation factor 5A. In Salmonella, deletion of the efp gene results in pleiotropic phenotypes, including increased susceptibility to numerous cellular stressors. Only a limited number of proteins are affected by the loss of EF-P, and it has recently been determined that EF-P plays a critical role in rescuing ribosomes stalled at PPP and PPG peptide sequences. Here we present an unbiased in vivo investigation of the specific targets of EF-P by employing stable isotope labeling of amino acids in cell culture (SILAC) to compare the …

Intrinsic Apoptotic Pathway: Effects Of Calcium On Murine Cytochrome C Release In Brain And Liver Mitochondria, Dane M. Edwards

Senior Honors Theses

A cell may use one of three main apoptotic pathways leading to programmed cell death: the extrinsic pathway, the perforin/granzyme pathway and the intrinsic pathway. The most pertinent to this discussion is the intrinsic pathway, which utilizes the mitochondria as an essential intermediary. Mitochondria’s primary function in relation to this pathway is the subsequent release of pro-apoptotic factors including cytochrome c, which activate a caspase cascade leading to the death of the cell. Cytochrome c is released partly due to an increase in cytosolic calcium levels. Two methods of the release of cytochrome c have been proposed. The first is …

The Effects Of Intermittent Isometric Fatigue On Concentric, Eccentric, And Isometric Torque, Robert W. Lewis Jr.

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Fatiguing intermittent isometric (ISO) muscle actions of the leg extensors have been shown to result in a similar percent (%) decline in torque for concentric (CON), eccentric (ECC), and ISO muscle actions. However, the effects of intermittent ISO fatigue of the forearm flexors on CON, ECC, and ISO torque, have not been established. The purpose of this investigation was to determine the effects of 50 maximal, intermittent ISO forearm flexion muscle actions on CON, ECC, and ISO torque. Twenty adults (10 men (mean ± SD age = 21.9 ± 2.3 years) and 10 women (mean ± SD age = 22.7 …

A Pilot Study Exploring The Quadratic Nature Of The Relationship Of Strength To Performance Among Shot Putters, Lawrence W. Judge, David Bellar, Ashley Thrasher, Laura Simon, Omar S. Hindawi, Elizabeth Wanless

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 171-179, 2013. The purpose of this pilot study was to examine the quadratic nature of the relationship between the strength and throwing distance in the shot put. A survey was sent to throws coaches with Master Coach or USA Track and Field Level III distinction to examine fifty-three collegiate and elite throwers (24 male, 29 female). The coaches reported the thrower’s personal best shot put distance and preseason weight room 1RM for bench press, power clean, and squat exercises. Relationship between distance and 1RM was determined via general linear model polynomial contrast analysis …

Validity Of Borg Ratings Of Perceived Exertion During Active Video Game Play, Brandon S. Pollock, Jacob E. Barkley, Nick Potenzini, Renee M. Desalvo, Stacey L. Buser, Ronald Otterstetter, Judith A. Juvancic-Heltzel

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 164-170, 2013. During physically interactive video game play (e.g., Nintendo Wii), users are exposed to potential distracters (e.g., video, music), which may decrease their ratings of perceived exertion (RPE) throughout game play. The purpose of this investigation was to determine the association between RPE scores and heart rate while playing the Nintendo Wii. Healthy adults (N = 13, 53.5 ± 5.4 years old) participated in two exercise sessions using the Nintendo Wii Fit Plus. During each session participants played a five-minute warm-up game (Basic Run), two separate Wii Fit Plus games (Yoga, Strength …

Kinesio Tape® Applied To The Thorax Augments Ventilatory Efficiency During Heavy Exercise, Kindal Malehorn*, Jodi Hiniker*, Theresa Mackey‡, Kristin J. Heumann‡, Steven Ross Murray‡, Robert W. Pettitt‡

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 157-163, 2013. Kinesio Tape® (KT) is purported to help coordinate involuntary contractions. KT applied to the thorax is believed to enhance breathing during constant-load exercise, but verification is lacking. We had 12 participants complete a graded exercise test to determine gas-exchange threshold (GET), and two, constant-load bouts sufficient in intensity to evoke the VO2 slow component using no tape (NT) or KT applied to the thorax, respectively, in counterbalanced order. Indirect calorimetery measured ventilatory and gas-exchange parameters, and a 3-lead EKG recorded heart rate (HR). A greater expiratory tidal volume (+150 mL·min-1) along …

Stress Reactivity In Humans And Animals: Two Meta-Analyses, Brad Wipfli, Ernesto Ramirez

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 144-156, 2013. Previous meta-analyses examining the effects of exercise on stress reactivity have included methodologically weak studies; we therefore conducted a meta-analysis utilizing more stringent inclusion criteria. An analysis of 33 randomized controlled trials involving humans (N = 1,252) revealed a moderate effect (ES = -0.31; 95% CI = -.43, -.20) for exercise as a method to reduce stress reactivity. An additional analysis with 27 randomized controlled trials of physical activity in animals (N = 462) also revealed a moderate reduction (ES = -0.33; 95% CI = -0.15, -0.52) …

The Impact Of Classroom Activity Breaks On The School-Day Physical Activity Of Rural Children, Teresa Bershwinger, Timothy A. Brusseau

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 134-143, 2013. Schools have been identified as a central element in a system that ensures that children participate in enough physical activity to develop healthy lifestyles. Even with this recommendation, many school-based physical activity opportunities are being eliminated/minimized (i.e. physical education (PE), recess). With children spending much of their time at school, other supplemental physical activity opportunities are essential. One such opportunity is through classroom teacher led activity breaks. Very little evidence exists identifying the impact of classroom activity breaks on the daily physical activity patterns of children. Therefore, the purpose of this …

Effects Of Exercise Sequence In Resistance-Training On Strength, Speed, And Agility In High School Football Players, Shawn Johnson, Steve Burns, Kari Azevedo

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 126-133, 2013. Manipulating variables in a training program (e.g., sets, reps, lifts, sequence, etc.) is designed to maximize strength and power performance. Due to the complexity of designing resistance-training programs, changing one variable could potentially set an athletic team apart from others in performance. The purpose of this study was to investigate if exercise sequence could influence the development of strength, speed, and agility. This study compared two specific types of exercise sequences: traditional, which performs the prescribed exercises in a traditional or blocked manner (by completing every set of an exercise before …

Effects Of Foot Position During Squatting On The Quadriceps Femoris: An Electromyographic Study, Nicholas G. Murray, Daniel Cipriani, Denise O'Rand, Rebecca Reed-Jones

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 114-125, 2013. Weightlifters have commonly believed that changing joint position can alter specific muscle activation. The magnitude of force produced by a muscle is highly dependent upon the length of the muscle. The purpose of this study was to determine the effect of foot positioning on muscle activation of the superficial quadriceps as measured by surface electromyography (sEMG) during a functional squatting movement in healthy adults. Twenty physically active asymptomatic adults (7 females and 13 males) were included in the study while four different foot positions (Neutral, Internally Rotated, Externally Rotated, and Staggered) …

Validation Of Omron™ Pedometers Using Mti Accelerometers For Use With Children, Bradley P. Peters, Kate A. Heelan Phd, Bryce M. Abbey

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 106-113, 2013. The MTI accelerometer is highly regarded as a reliable means to measure physical activity in children (Trost et. al., 1998); however, it is not always a practical instrument to use. Pedometers offer an alternative method of activity measurement and are often more practical. PURPOSE: To validate Omron™ pedometer (steps/day) against MTI accelerometer (counts /day and moderate to vigorous physical activity (MVPA) min/day) for children. METHODS: 190 children (88 males, 102 females, 8.7±2.1 yrs, 76.9±27.5 BMI %tile) wore an MTI accelerometer and Omron™ pedometer attached to the same belt for 3.9±2.2 days. …

Acute Ingestion Of L-Arginine Alpha-Ketoglutarate Fails To Improve Muscular Strength And Endurance In Rotc Cadets, Benjamin Wax, Jerry J. Mayo, Laura A. Hilton, Harris C. Mareio, Justin D. Miller, Heather E. Webb, Brian Lyons

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 91-97, 2013. L-Arginine Alpha-Ketoglutarate (AAKG) is purported to stimulate the release of nitric oxide, and is suggested to facilitate muscular performance by increasing blood flow and increase oxygen and nutrient delivery to the working muscle. However, the ergogenic benefit of AAKG during resistance exercise has not been established. Therefore the purpose of this study was to investigate the effects of acute AAKG ingestion in active ROTC Cadets on measures of one-repetition maximal strength (1RM) and muscular endurance. Nineteen apparently healthy males ingested either AAKG (3 g) or a placebo 45 minutes prior to …

Examination Of Injury In Female Gaelic Football, Justin Brown, Charilaos Papadopoulos, Robert Pritchett

International Journal of Exercise Science

International Journal of Exercise Science 6(2) : 98-105, 2013. To examine the relationship between body mass index and injury as well as examine injury according to playing position. In addition we sought to describe injury as it pertains to female Gaelic football. Data was collected using an online questionnaire. Archived data was also collected from a ladies Gaelic football team located in Washington, USA. Respondents included 74 recreationally trained female Gaelic footballers aged 15 – 45 years and a playing experience of 1 – 24 years. Respondents were asked to recall injuries that resulted from participation in Gaelic football. A …

Characterization Of The Neurotrophic Factor Brain-Derived Neurotrophic Factor (Bdnf) In Intestinal Smooth Muscle Cells, Mohammad Alqudah

Theses and Dissertations

Brain-derived neurotrophic factor (BDNF) belongs to the neurotrophin family of secreted proteins, which include in addition to BDNF, nerve growth factor (NGF) and neurotrophin 3-6 (NT-3-6). BDNF mediates its functions by activating two cell surface receptors, pan-neurotrophin receptor (P75NTR) and tropomyosin-related kinase B (TrkB) and their downstream intracellular cascades. BDNF is best known for its role in neuronal survival, regulation of neuronal differentiation, migration and activity-dependent synaptic plasticity. However, BDNF is widely expressed in non-neuronal tissues as well. The localization and the function of BDNF in intestinal smooth muscle cells (SMCs) are not well defined. Thus, the main purpose of …

Sildenafil Attenuates Ethanol-Induced Cardiomyocyte Injury And Preserves Cardiac Function Through Protein Kinase G-Dependent Signaling, Gregory R. Sturz

Theses and Dissertations

Background: Ethanol is a cardiotoxic substance that damages the heart by increasing apoptosis, free radical formation and calcium overloading. Consequently, there is an increase in cell death leaving fewer functioning myocytes leading to heart failure. Sildenafil is a phosphodiesterase type-5 (PDE-5) inhibitor approved for treatment of erectile dysfunction. Studies from our lab have demonstrated that PDE-5 inhibition reduces myocardial infarct size and attenuates post-ischemic cardiac dysfunction in both ischemia-reperfusion and permanent coronary artery ligation models. Therefore, in the present study, we hypothesized that treatment with sildenafil will prevent cardiotoxicity associated with acute alcohol exposure by reducing myocyte apoptosis and preserving …

Regulation Of Gastrointestinal Smooth Muscle Function By Hydrogen Sulfide, Ancy Nalli

Theses and Dissertations

Inhibitory neurotransmitters, chiefly nitric oxide and vasoactive intestinal peptide, cause MLC20 dephosphorylation and muscle relaxation via inhibition of myosin light chain (MLC) kinase and activation of MLC phosphatase. Hydrogen sulfide (H2S) produced as a byproduct by luminal sulfate-reducing commensal bacteria or as an endogenous signaling molecule synthesized from L-cysteine via cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS) regulates muscle contraction. However, the role of H2S in the regulation of MLC phosphatase activity and MLC20 phosphorylation is not known. The aim of the present study was to examine the expression of CSE and CBS in smooth muscle cells and to elucidate the molecular …