Physiology Commons^™

Aberrant Sialylation Alters Cardiac Electrical Signaling, Andrew Ednie

USF Tampa Graduate Theses and Dissertations

In the heart, electrical signaling is responsible for its rhythmicity and is necessary to initiate muscle contraction. The net electrical activity in a cardiac myocyte during a contraction cycle is observed as the action potential (AP), which describes a change in membrane potential as a function of time. In ventricular cardiac myocytes, voltage-gated sodium channels (Nav) and voltage-gated potassium channels (Kv) play antagonistic roles in shaping the AP with the former initiating membrane depolarization and the latter repolarizing it. Functional changes in the primary cardiac Nav isoform, Nav 1.5, or any one of the many Kv isoforms expressed in the …

Map Kinases Couple Hindbrain-Derived Catecholamine Signals To Hypothalamic Adrenocortical Control Mechanisms During Glycemia-Related Challenges, Arshad Khan, Kimberly Kaminski, Graciela Sanchez-Watts, Todd Ponzio, J. Kuzmiski, Jaideep Bains, Alan Watts

Selected Works Temporary Series

No abstract provided.

Map Kinases Couple Hindbrain-Derived Catecholamine Signals To Hypothalamic Adrenocortical Control Mechanisms During Glycemia-Related Challenges, Khan, Kimberly Kaminski, Graciela Sanchez-Watts, Todd Ponzio, J. Kuzmiski, Jaideep Bains, Alan Watts

Departmental Papers (Biology)

No abstract provided.

Store-Operated Calcium Channels In The Function Of Intracardiac Neurons, Timetria Bonds

USF Tampa Graduate Theses and Dissertations

Proper autonomic regulation of mammalian cardiac function is dependent upon very complex and precise communication among the intracardiac ganglia and individual neurons within the ganglia. An array of neuromodulators is found within the ganglia that direct neuronal activity by modulating the movement of calcium. The current study determines that opioidergic agonists, which have been found to contribute to severe cardiac disease states and intracellular calcium mobilization, are also responsible for changes in the function of the intracardiac neuron via their effects on store-operated calcium channels (SOCs).

Previous studies suggest that phosphorylation plays a role in SOC regulation. Using Fura-2 calcium …

Functional Plasticity Of Central Trpv1 Receptors In Brainstem Dorsal Vagal Complex Circuits Of Streptozotocin-Treated Hyperglycemic Mice, Andrea Zsombok, Muthu D. Bhaskaran, Hong Gao, Andrei V. Derbenev, Bret N. Smith

Physiology Faculty Publications

Emerging data indicate that central neurons participate in diabetic processes by modulating autonomic output from neurons in the dorsal motor nucleus of the vagus (DMV). We tested the hypothesis that synaptic modulation by transient receptor potential vanilloid type 1 (TRPV1) receptors is reduced in the DMV in slices from a murine model of type 1 diabetes. The TRPV1 agonist capsaicin robustly enhanced glutamate release onto DMV neurons by acting at preterminal receptors in slices from intact mice, but failed to do so in slices from diabetic mice. TRPV1 receptor protein expression in the vagal complex was unaltered. Brief insulin preapplication …

Beta-Lysine Discrimination By Lysyl-Trna Synthetase, Marla S. Gilreath, Hervé Roy, Tammy J. Bullwinkle, Assaf Katz, Michael Ibba, William Wiley Navarre

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P is modified with (R)‐β‐lysine by the lysyl‐tRNA synthetase (LysRS) paralog PoxA. PoxA specificity is orthogonal to LysRS, despite their high similarity. To investigate α‐ and β‐lysine recognition by LysRS and PoxA, amino acid replacements were made in the LysRS active site guided by the PoxA structure. A233S LysRS behaved as wild type with α‐lysine, while the G469A and A233S/G469A variants decreased stable α‐lysyl‐adenylate formation. A233S LysRS recognized β‐lysine better than wildtype, suggesting a role for this residue in discriminating α‐ and β‐amino acids. Both enantiomers of β‐lysine were substrates for tRNA aminoacylation by LysRS, which, together with …

Load Carriage Distance Run And Pushups Tests: No Body Mass Bias And Occupationally Relevant, Paul M. Vanderburgh, Nicholas S. Mickley, Philip A. Anloague, Kimber Lucius

Health and Sport Science Faculty Publications

Recent research has demonstrated body mass (M) bias in military physical fi tness tests favoring lighter, not just leaner, service members. Mathematical modeling predicts that a distance run carrying a backpack of 30 lbs would eliminate M-bias. The purpose of this study was to empirically test this prediction for the U.S. Army push-ups and 2-mile run tests. Two tests were performed for both events for each of 56 university Reserve Offi cer Training Corps male cadets: with (loaded) and without backpack (unloaded). Results indicated signifi cant M-bias in the unloaded and no M-bias in the loaded condition for both events. …

Aging And Sympathetic Neurotransmission In Two Strains Of Rats That Differ In Longevity And Immune Profiles, Sam David Perez

Loma Linda University Electronic Theses, Dissertations & Projects

Age-related changes in sympathetic neurotransmission in immune organs may be associated with immunosenescence; however no causal relationship has been established. From previous studies in Fischer rats (F344), we have found that during middle age, sympathetic nerve activity (SNA) rises in the spleen followed by a decline in noradrenergic (NA) innervation. Also, increased sympathetic signaling via betaadrenergic receptor (β-AR) and reduced proliferation of lymphocytes are evident with increasing age. Although SNA progressively rises with age, effects of age on sympathetic factors may be different across rat strains. If causal relationships exist between sympathetic activity and immune function, they may be related …

Spiking Patterns And Their Functional Implications In The Antennal Lobe Of The Tobacco Hornworm Manduca Sexta, Hong Lei, Carolina E. Reisenman, Caroline H. Wilson, Prasad Gabbur, John G. Hildebrand

Health Sciences and Kinesiology Faculty Articles

Bursting as well as tonic firing patterns have been described in various sensory systems. In the olfactory system, spontaneous bursts have been observed in neurons distributed across several synaptic levels, from the periphery, to the olfactory bulb (OB) and to the olfactory cortex. Several in vitro studies indicate that spontaneous firing patterns may be viewed as “fingerprints” of different types of neurons that exhibit distinct functions in the OB. It is still not known, however, if and how neuronal burstiness is correlated with the coding of natural olfactory stimuli. We thus conducted an in vivo study to probe this question …

The Trna Synthetase Paralog Poxa Modifies Elongation Factor-P With (R)-Β-Lysine, Hervé Roy, S. Betty Zou, Tammy J. Bullwinkle, Benjamin S. Wolfe, Marla S. Gilreath, Craig J. Forsyth, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The lysyl-tRNA synthetase paralog PoxA modifies elongation factor P (EF-P) with α-lysine at low efficiency. Cell-free extracts containing non–α-lysine substrates of PoxA modified EF-P with a change in mass consistent with addition of β-lysine, a substrate also predicted by genomic analyses. EF-P was efficiently functionally modified with (R)-β-lysine but not (S)-β-lysine or genetically encoded α-amino acids, indicating that PoxA has evolved an activity orthogonal to that of the canonical aminoacyl-tRNA synthetases.

The Role Of The Androgen Receptor Cofactor P44/Wdr77 In Astrocyte Activation, Bryce H. Vincent

Dissertations and Theses (Open Access)

Astrogliosis is induced by neuronal damage and is also a pathological feature of the major aging-related neurodegenerative disorders. The mechanisms that control the cascade of astrogliosis have not been well established. In a previous study, we identified a novel androgen receptor (AR)-interacting protein (p44/WDR77) and found that it plays a critical role in the control of proliferation and differentiation of prostate epithelial cells. In the present study, we found that deletion of the p44 gene in the mouse brain caused accelerated aging with dramatic astrogliosis. The p44/WDR77 is expressed in astrocytes and loss of p44/WDR77 expression in astrocytes leads to …

Plantar Pressure Distribution Differences In Physically Active Individuals With And Without Functional Ankle Instability During A Side Cut, J'Nai Pittman

Human Movement Studies & Special Education Theses & Dissertations

Context: Functional ankle instability (FAI) is a popular condition in the physically active population. There is a surplus of evidence to demonstrate how FAI decreases proprioception, balance, and overall athletic performance. However, to date there is no evidence that demonstrates how F AI correlates to alterations in plantar pressure distribution differences in a physically active population while completing athletic tasks. Objective: To assess differences in plantar pressure distributions while completing a side cut in individuals with and without FAI. Design: Observational case-control. Setting: Outdoor field turf and research laboratory. Participants: Fifty ankles from physically active individuals (FAI: age= 21.47±3.02 yrs; …

Effects Of Diet Type And Supplementation Of Glucosamine, Chondroitin, And Msm On Body Composition, Functional Status, And Markers Of Health In Women With Knee Osteoarthritis Initiating A Resistance-Based Exercise And Weight Loss Program, Teresa Magrans-Courtney, Colin Wilborn, Christopher Rasmussen, Maria Pontes Ferreira, Lori Greenwood, Bill Campbell, Chad M. Kerksick, Erica Nassar, Rui Li, Mike Iosia, Matt Cooke, Kristin Dugan, Darryn Willoughby, Luann Soliah, Richard B. Kreider

Nutrition and Food Science Faculty Research Publications

Background: The purpose of this study was to determine whether sedentary obese women with knee OA initiating an exercise and weight loss program may experience more beneficial changes in body composition, functional capacity, and/or markers of health following a higher protein diet compared to a higher carbohydrate diet with or without GCM supplementation.

Methods: Thirty sedentary women (54 ± 9 yrs, 163 ± 6 cm, 88.6 ± 13 kg, 46.1 ± 3% fat, 33.3 ± 5 kg/m²) with clinically diagnosed knee OA participated in a 14-week exercise and weight loss program. Participants followed an isoenergenic low fat higher …

Ischemia Impairs Vasodilation In Skeletal Muscle Resistance Artery, Kyle Remington Struthers

Master's Theses

Functional vasodilation in arterioles is impaired with chronic ischemia. We sought to examine the impact of chronic ischemia and age on skeletal muscle resistance artery function. To examine the impact of chronic ischemia, the femoral artery was resected from young (2-3mo) and adult (6-7mo) mice and the profunda femoris artery diameter was measured at rest and following gracilis muscle contraction 14 days later using intravital microscopy. Functional vasodilation was significantly impaired in ischemic mice (14.4±4.6% vs. 137.8±14.3%, p<0.0001 n=8) and non-ischemic adult mice (103.0±9.4% vs. 137.8±14.3%, p=0.05 n=10). In order to analyze the cellular mechanisms of the impairment, a protocol was developed to apply pharmacological agents to the experimental preparation while maintaining tissue homeostasis. Endothelial and smooth muscle dependent vasodilation were impaired with ischemia, 39.6 ± 13.6% vs. 80.5 ± 11.4% and 43.0 ± 11.7% vs. 85.1 ± 10.5%, respectively. From this data, it can be supported that smooth muscle dysfunction is the reason for the observed impairment in arterial vasodilation.

A New Single Workbout Test To Estimate Critical Power And Anaerobic Work Capacity, Haley Bergstrom

Department of Nutrition and Health Sciences: Dissertations, Theses, and Student Research

The purpose of the present study was to develop a new 3-min, single workbout test to estimate critical power (CP) and anaerobic work capacity (AWC) using the Monark cycle ergometer with the resistance based on the individual’s body weight. Twelve moderately-trained adults (6 men and 6 women; mean age ± SD = 23.2 ± 3.5 yr) performed an incremental cycle ergometer test to exhaustion. The CP and AWC were estimated from the original work limit (W_lim) versus time limit (T_lim) relationship (CP_PT) and a 3-min all-out test (CP_3min) against a fixed resistance …

Run Like A Kenyan: How To Be An Elite Athlete The Kenyan Way, Becca Blubaugh

Undergraduate Research Conference

By observation and statistics, research shows that one dominating elite group in running is the Kenyan distance runners, specifically the Kalenjinethnic group. Many aspects of the Kenyan life were found to contribute to their efficiency and success. Analyzing Kenyan aspects of environment, altitude, society, diet, transportation, motives, and training may reveal possible ways American runners can improve their running.

The Comparison Of Hamstring/Quadriceps Strength Ratio In The Dominant Versus The Non-Dominant Leg Of Elite Female Artistic Gymnasts, Marina Moure

Human Movement Studies & Special Education Theses & Dissertations

The majority of the injuries in women's artistic gymnastics occur in the lower limbs (Marshall et al, 2007). Hamstring muscle strains are prevalent in sports that involve sprinting (Ekstrand & Quillist, 1985; Orchard, 2001; Croisier et al., 2008) with a high reinjury ratio (Orchard, 1993; Orchard, 1997). Recent studies have linked an increase of muscle injury rate in the lower limbs to strength muscle imbalance between legs and the relation between the hamstring and quadriceps strength (Croisier et al., 2002; Yamamoto, 2008; Sugiura et al, 2008). In order to determine if there is an imbalance in women's artistic gymnastics, forty-three …

Effect Of Body Mass And Added Mass On Treadmill Performance, Rachel Elizabeth Walker

Human Movement Studies & Special Education Theses & Dissertations

Strenuous physical activity in extreme environments is an important part of the activities of military personnel. The average infantry combat load for an infantry on the loaded tasks. Subjects performed an outdoor 4.8-km run and four maximal treadmill tests wearing the loads listed above. Subjects' pulmonary function was tested with load prior to each treadmill session. Peak values of heart rate, VO₂, exercise ventilation, and respiratory exchange ratio were measured at the end of each maximal treadmill test. Significant decreases were found in pulmonary function measures (FEV₁, FVC and MVV) with increasing load. Most peak responses …

Aberrant Promoter Cpg Methylation Is A Mechanism For Impaired Phd3 Expression In A Diverse Set Of Malignant Cells., Trenton L. Place, Matthew P. Fitzgerald, Sujatha Venkataraman, Sabine U. Vorrink, Adam J. Case, Melissa L.T. Teoh, Frederick E. Domann

Journal Articles: Cellular & Integrative Physiology

BACKGROUND: The prolyl-hydroxylase domain family of enzymes (PHD1-3) plays an important role in the cellular response to hypoxia by negatively regulating HIF-α proteins. Disruption of this process can lead to up-regulation of factors that promote tumorigenesis. We observed decreased basal expression of PHD3 in prostate cancer tissue and tumor cell lines representing diverse tissues of origin. Furthermore, some cancer lines displayed a failure of PHD3 mRNA induction when introduced to a hypoxic environment. This study explores the mechanism by which malignancies neither basally express PHD3 nor induce PHD3 under hypoxic conditions.

METHODOLOGY/PRINCIPAL FINDINGS: Using bisulfite sequencing and methylated DNA enrichment …

Human Chondrosarcoma Cells Acquire An Epithelial-Like Gene Expression Pattern Via An Epigenetic Switch: Evidence For Mesenchymal-Epithelial Transition During Sarcomagenesis., Matthew P. Fitzgerald, Francoise Gourronc, Melissa L.T. Teoh, Matthew J. Provenzano, Adam J. Case, James A. Martin, Frederick E. Domann

Journal Articles: Cellular & Integrative Physiology

Chondrocytes are mesenchymally derived cells that reportedly acquire some epithelial characteristics; however, whether this is a progression through a mesenchymal to epithelial transition (MET) during chondrosarcoma development is still a matter of investigation. We observed that chondrosarcoma cells acquired the expression of four epithelial markers, E-cadherin,desmocollin 3, maspin, and 14-3-3σ, all of which are governed epigenetically through cytosine methylation. Indeed, loss of cytosine methylation was tightly associated with acquired expression of both maspin and 14-3-3σ in chondrosarcomas. In contrast, chondrocyte cells were negative for maspin and 14-3-3σ and displayed nearly complete DNA methylation. Robust activation of these genes was also …

Effect Of Dimethylarginine Dimethylaminohydrolase In The Development Of Salt Sensitivity, Samar Abdulla Nasser

Wayne State University Dissertations

Salt sensitivity is associated with a rise in blood pressure (BP) occurring during sodium loading and/or a fall in BP during sodium restriction that exceeds random fluctuations in BP. Salt sensitivity is more common in African American than Caucasian hypertensives and is also present, in normotensive African Americans. The mechanism or mechanisms resulting in salt-sensitive hypertension are multiple and include both activation of the renin angiotensin system via increases in angiotensin II and reductions in the endogenous vasodilator, nitric oxide (NO). An important means of NO downregulation is through asymmetric dimethylarginine (ADMA), an endogenous NO inhibitor, which is largely metabolized …

Dose-Dependent Thresholds Of 10-Ns Electric Pulse Induced Plasma Membrane Disruption And Cytotoxicity In Multiple Cell Lines, Bennett L. Ibey, Caleb C. Roth, Andrei G. Pakhomov, Joshua A. Bernhard, Gerald J. Wilmink, Olga N. Pakhomova

Bioelectrics Publications

In this study, we determined the LD50 (50% lethal dose) for cell death, and the ED50 (50% of cell population staining positive) for propidium (Pr) iodide uptake, and phosphatidylserine (PS) externalization for several commonly studied cell lines (HeLa, Jurkat, U937, CHO-K1, and GH3) exposed to 10-ns electric pulses (EP). We found that the LD50 varied substantially across the cell lines studied, increasing from 51 J/g for Jurkat to 1861 J/g for HeLa. PS externalized at doses equal or lower than that required for death in all cell lines ranging from 51 J/g in Jurkat, to 199 J/g in CHO-K1. Pr …

The Impact Of Tricaine Methanesulfonate, 2-Phenoxyethanol, And Carvone-Methyl Salicylate On The Innate Immune Response Of Zebrafish (Danio Rerio), Charles R. Wulff

Honors Theses

Anesthesia plays a vital role in the maintenance of aquaculture species, where it is used to minimize stress during complex handling tasks such as transport, assessment, and harvesting. However, anesthetics have been shown to suppress the innate immune response, which could impact immunity and increase risk of infection. Tricaine methanesulfonate (MS-222) and 2-Phenoxyethanol (2-PE) represent two of the most commonly used anesthetics in aquaculture, with R-(+)-carvone, in the form of carvone-methyl salicylate (CMS) has recently been proposed as an alternative anesthetic for food fish. These three anesthetics were used to assess the influence of anesthetics on the immune system of …

Dog Models Of Naturally Occurring Cancer, Donna O. Mccarthy

College of Nursing Faculty Research and Publications

Studies using dogs provide an ideal solution to the gap in animal models for natural disease and translational medicine. This is evidenced by approximately 400 inherited disorders being characterized in domesticated dogs, most of which are relevant to humans. There are several hundred isolated populations of dogs (breeds) and each has a vastly reduced genetic variation compared with humans; this simplifies disease mapping and pharmacogenomics. Dogs age five- to eight-fold faster than do humans, share environments with their owners, are usually kept until old age and receive a high level of health care. Farseeing investigators recognized this potential and, over …

Mechanisms Of Translation Arrest Following Focal Brain Ischemia, Monique K. Lewis

Wayne State University Dissertations

MECHANISMS OF TRANSLATION ARREST FOLLOWING FOCAL BRAIN

ISCHEMIA

by

MONIQUE K. LEWIS

August 2011

Advisor: Dr. Donald DeGracia

Major: Physiology

Degree: Doctor of Philosophy

The loss of blood flow to the brain is termed ischemia and the subsequent resumption of blood flow is termed reperfusion. Brain ischemia and reperfusion (I/R) occurs primarily following resuscitation from cardiac arrest and stroke and presents one of the most significant clinical challenges. At present, there are no clinically effective pharmacologic interventions to halt brain damage following I/R. The major Aim of this dissertation will be to investigate possible mechanisms involved in neuron death following …

Mechanisms Of Persistent Translation Arrest Following Global Brain Ischemia And Reperfusion, Jill Theresa Jamison

Wayne State University Dissertations

ABSTRACT

MECHANISMS OF PERSISTENT TRANSLATION ARREST FOLLOWING GLOBAL BRAIN ISCHEMIA and REPERFUSION

by

JILL T. JAMISON

December 2011

Advisor: Donald J. DeGracia, Ph.D.

Major: Physiology

Degree: Doctor of Philosophy

The information presented here studies the mechanisms that underlie persistent translation arrest (TA) following global brain ischemia and reperfusion (I/R). To summarize the main findings I have discovered a new mechanism for prolonged post-ischemic TA that correlated exactly with in vivo translation rates and correlated precisely with cell outcome. Through the extensive colocalization studies, my results indicate that the mRNA granules are ribonomic structures involved with mRNA regulation. This finding is …

The Absence Of Abcd2 Reveals A Novel Role For Peroxisomes In The Protection From Metabolic Syndrome, Jingjing Liu

University of Kentucky Doctoral Dissertations

ABCD2 (D2) is a peroxisomal ATP binding cassette (ABC) transporter that is expressed in brain, adrenal and liver. D2 is transcriptionally regulated by key transcriptional factors that control lipid and glucose metabolism. Therefore, we examined its role in adipose tissue. These studies revealed that D2 is highly abundant in adipose tissue and upregulated during adipogenesis. However, D2 deficiency does not affect either adipogenesis or lipid accumulation. An examination of the lipid profile of adipose tissue revealed the accumulation of C20 and C22 fatty acids in D2 deficient (D2‐/‐) mice. When challenged with a diet enriched in erucic acid (C22:1, 10% …

The Potential Role Of Innate Immunity In The Pathogenesis Of Post-Operative Adhesions, Jennell White

Wayne State University Dissertations

Post-operative adhesion development occurs in the vast majority of patients following abdominal surgery and is a natural occurrence of peritoneal-wound healing. These fibrous bands may form within the first 5-7 days post-surgery and have the ability to cause a distortion in the normal anatomical positioning of abdominal organs. Consequently, adhesions are major contributors to small bowel obstruction, infertility, and severe pelvic and abdominal pain. Physiological processes responsible for adhesion formation remain obscure though it is believed to involve cell migration, proliferation, and differentiation of several cell types including mesothelial cells, fibroblasts, and inflammatory and immune cells. Substances released from these …

Secreted Factors From Human Umbilical Cord Blood Cells Protect Oligodendrocytes From Ischemic Insult, Derrick Rowe

USF Tampa Graduate Theses and Dissertations

Oligodendrocytes (OL)s are the dominant cell type in the white matter and are integral for synaptic transmission essential for proper neuronal communication between brain areas. Previous studies have shown that intravenous administration of the mononuclear fraction of human umbilical cord blood (HUCB) cells in rat models of stroke reduced white matter injury, gray matter injury and behavioral deficits. Yet the mechanisms used by HUCB cells remain unknown in ischemic injury. These studies will investigate both in vitro and in vivo approaches to elucidate this mechanism in OLs. When mature primary OLs were coincubated with HUCB cells, HUCB cells secreted soluble …

Lateral Blood Flow Velocity Estimation Based On Ultrasound Speckle Size Change With Scan Velocity, Tiantian Xu, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Conventional (Doppler-based) blood flow velocity measurement methods using ultrasound are capable of resolving the axial component (i.e., that aligned with the ultrasound propagation direction) of the blood flow velocity vector. However, these methods are incapable of detecting blood flow in the direction normal to the ultrasound beam. In addition, these methods require repeated pulse-echo interrogation at the same spatial location. A new method has been introduced which estimates the lateral component of blood flow within a single image frame using the observation that the speckle pattern corresponding to blood reflectors (typically red blood cells) stretches (i.e., is smeared) if the …