Medicine and Health Sciences Commons^™

Perceptual Variations In Thermoregulation During Exercise In A Hot Environment, William C. Alger

Electronic Theses and Dissertations

ABSTRACT

Professionals are seeking to find ways to prevent exertional heat illness (EHI) in populations working in hot environments as well as populations that are physically active. The purpose of the present study was to evaluate individuals’ ability to accurately perceive core temperature ranges associated with homeothermic and EHI temperatures during exercise. Ten physically active males exercised on a treadmill at a self-selected rate until core temperature reached 39°C. Participants rated perceived core and skin temperature on 100 mm scales each time core temperature increased 0.25˚ C (37.5-39.0˚ C), along with thermal comfort and sweating sensation. During exercise core temperature …

The Role Of The Mir-200 Family On The Tumor Suppressor Rassf2 And The Effect On Mapk Pathway Activity In Colorectal Cancer., Jane V. Carter

Electronic Theses and Dissertations

This dissertation investigated the role of the miR-200 family in normal colon epithelial (CCD 841) and Dukes’ C (HT-29) colorectal cancer (CRC) cell lines. Our aim was to characterize expression of the miR-200 family (miR-200a, miR-200b, miR-200c, miR-141, and miR-429) in colorectal cell lines, study their effect on the tumor suppressor Ras Associated Domain-Containing Protein (RASSF) 2 and on subsequent activity within the mitogen-activated protein kinase (MAPK) signaling pathway. We wanted to determine whether regulation of miR-200 family members could change cell behavior towards more “cancer-like” in a normal colon epithelium (CCD 841) cell line, or less “cancer-like” in a …

Evaluating Cardiovascular Dysfunction During Increased Activity And Exercise Rehabilitation Following Incomplete Thoracic Spinal Cord Injury In The Adult Rat., Kathryn A. Harman

Electronic Theses and Dissertations

Spinal cord injury (SCI) results in whole-body dysfunction. While the majority of SCI research is focused on improving locomotor function after injury, cardiovascular (CV) disease continues to be the leading cause of morbidity in the chronic SCI patient population. The combination of injury-induced destruction of autonomic pathways, maladaptive plasticity within lumbosacral circuits, and the progressive decline in physical fitness contribute to the poor CV status of SCI individuals. Currently, there is little emphasis on implementing appropriately-timed acute rehabilitation techniques aimed to curtail maladaptive remodeling and improve CV outcomes. Furthermore, no pre-clinical or clinical studies have investigated the most appropriate time-course …

The Role Of Nicotine, A7 Nicotinic Acetylcholine Receptors And Extracellular Matrix Remodeling In Pulmonary Fibrosis., Glenn Ward Vicary

Electronic Theses and Dissertations

The median survival for idiopathic pulmonary fibrosis (IPF) patients from diagnosis is a dismal 3 years. This condition is characterized by pulmonary fibroproliferation and excess production and disordered deposition of extracellular matrix (ECM) proteins resulting in obliteration of the original tissue architecture, loss of lung function and eventual death due to respiratory failure. The main hindrance to the development of effective treatments against pulmonary fibrosis is the late detection of its progression and is often of unknown cause. Tobacco smoke represents the most important environmental factor linked to the development of pulmonary fibrosis, with over 60% of IPF patients current …

The Effects Of Direct Peritoneal Resuscitation On Leukocyte Infiltration After Acute Brain Death., Jessica Lee Weaver

Electronic Theses and Dissertations

Background: Brain death triggers an inflammatory response that is associated with worse outcomes for recipients of transplanted organs procured from brain dead donors. The intestine has been shown to release inflammatory mediators in other types of shock, but its role is brain death is not well described. Direct peritoneal resuscitation (DPR) improves visceral organ blood flow and has been shown to reduce inflammation after hemorrhagic shock. Better understanding of this inflammatory process within the peripheral organs, the effects of DPR, and the role of the intestine could aid in better resuscitation of potential organ donors. Methods: Male Sprague-Dawley rats were …

Immune Monitoring In Recipients Of Combined Living Donor Kidney And Hematopoietic Stem/Facilitating Cell Transplants., Mark Dewayne Badder

Electronic Theses and Dissertations

Solid organ transplantation coupled with a hematopoietic stem cell transplant from the organ donor allows for the recipient to cease immunosuppressive therapy after transplant via a chimeric immune system. This beneficial effect of stem cell transplants is negatively affected by graft versus host disease (GVHD). Better understanding of the donor and recipient’s immune system is vital to mitigating graft versus host disease and induction of donor chimerism without GVHD. In this study, flow cytometry was used to characterize immune cells of the recipients’ before and up to eighteen months post transplantation. The recipients were categorized into their respective chimeric groups. …

Dynamic Host-Pathogen Interactions Result In Fungal Epitope Unmasking, Alex Hopke

Electronic Theses and Dissertations

Molecular camouflage is used by a diverse set of pathogens to disguise their identity and avoid recognition by protective host receptors. The opportunistic fungal pathogen Candida albicans is a good example, as it masks the inflammatory component β-glucan in its cell wall to evade detection by the immune receptor Dectin-1. Interestingly, it has been seen that β-glucan becomes unmasked during infection in vivo, though the underlying mechanisms remained unclear. Exposure levels of this epitope may be important, as Dectin-1 mediates protection from some strains of C. albicans and alterations in the organization and composition of the Candida cell wall …

Vinyl Chloride-Diet Interactions In Liver Disease : Potential Roles Of Autophagy And Energy Management., Anna L. Lang

Electronic Theses and Dissertations

Vinyl chloride (VC) is a prevalent environmental toxicant that has been shown to cause liver injury at high, occupational exposures. However, most studies have not addressed interactions of low doses with risk-modifying factors. This study aims to explore low-level VC metabolite exposure interactions with other potential risk-modifying factors and their effect on underlying liver disease. We examined sub-hepatotoxic effects of a VC metabolite (chloroethanol, CE) in two murine models of liver injury using ethanol and lipopolysaccharide (LPS). In both, CE significantly enhanced liver injury when compared to either ethanol or LPS alone. Previous studies have shown an increase in mTOR …

The Role Of O-Glcnacase During Heart Failure., Sujith Dassanayaka

Electronic Theses and Dissertations

Global augmentation of protein O-GlcNAcylation occurs in response to a myriad of stressors and confers a survival advantage at the cellular level. This protective phenomenon has been demonstrated to mediate cardioprotection through various in vitro and in vivo studies during ischemia-reperfusion, myocardial infarction, and oxidative stress; however, relatively little is known of the regulation of protein O-GlcNAcylation. Protein O-GlcNAcylation is regulated by two antagonistic enzymes, namely, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Ablation of cardiomyocyte OGT, the enzyme that catalyzes the addition of O-GlcNAc to proteins, exacerbates cardiac dysfunction during infarct-induced heart failure (HF). However, little is known of the …

Developing A More Clinically-Relevant Mouse Model Of Cisplatin-Induced Nephrotoxicity., Cierra N. Sharp

Electronic Theses and Dissertations

Cisplatin is a nephrotoxic chemotherapeutic that causes acute kidney injury (AKI) in 30% of patients. Although recovery can occur after one episode of cisplatin-induced AKI, studies have indicated multiple episodes may lead to the development of chronic kidney disease (CKD), an irreversible disease with no current treatments. The standard mouse model of cisplatin-induced AKI consists of one, high dose of cisplatin (> 20 mg/kg) that is lethal to the animal three days later. This model doesn’t accurately reflect the repeated dosing regimen patients receive, and doesn’t allow for long-term outcome studies of pathologies associated with CKD. We have developed a …

Toll-Like Receptor 4 Mutation Suppresses Hyperhomocysteinemia-Mediated Hypertension., Anastasia Familtseva

Electronic Theses and Dissertations

Background: Hyperhomocysteinemia (HHcy) has been observed to promote hypertension, but the mechanisms are unclear. Toll-like receptor 4 (TLR-4) is a cellular membrane protein that is ubiquitously expressed in all cell types of the vasculature. TLR-4 activation has been shown to promote inflammation that has been associated with pathogenesis of hypertension. In this study, we hypothesize that HHcy induces hypertension by TLR-4 activation that promotes inflammatory cytokine up-regulation (IL-1β, IL-6, TNF-α) and initiation of mitochondrial dysfunction leading to cell death and chronic vascular inflammation. Methods: To test this hypothesis, we used C57BL/6J mice (WT); Cystathionine-β-synthase deficient mice (CBS+/-) with genetic mild …

The Discovery Of A Novel, Ras-Mediated Nore1a/Pmliv Tumor Suppressor Complex., Jessica Mezzanotte Sharpe

Electronic Theses and Dissertations

Ras is the most commonly activated oncogene in human cancer. Activated Ras drives cell growth and proliferation by activating multiple mitogenic signaling pathways. However, Ras also has the paradoxical ability to promote anti-growth, pro-apoptotic, and pro-senescent signaling. The signaling pathways of many of these biological effectors remain poorly defined. One group of proteins capable of promoting Ras-induced apoptosis and cell cycle arrest is the RASSF family of tumor suppressors. Novel Ras Effector 1A, or NORE1A, was the first member of this family discovered and is a bona fide tumor suppressor that is lost or inactivated in a number of different …

In Vivo Monitoring Of Therapeutic Efficacy And Virulence Profile By Bioluminescent Klebsiella Pneumoniae., Ramy Ameen Fodah

Electronic Theses and Dissertations

Klebsiella pneumoniae causes an acute respiratory infection in human with severe outcomes and high mortality rates even with antibiotic treatment. Even with its critical clinical importance, few virulence systems have been identified for K. pneumoniae limiting the development of new therapeutic strategies. Accordingly, we performed Next Generation sequencing for the strain ATCC 43816, a virulent strain in mouse respiratory disease models, and compared its genomic data with two previously sequenced strains NTUH-K2044 and MGH 78578 for the purpose of identifying genes required for colonizing host lungs. Furthermore, the virulence potential of the three K. pneumoniae strains were tested in a …

Investigation Of Novel Functions For Dna Damage Response And Repair Proteins In Escherichia Coli And Humans, Benjamin A. Hilton

Electronic Theses and Dissertations

Endogenous and exogenous agents that can damage DNA are a constant threat to genome stability in all living cells. In response, cells have evolved an array of mechanisms to repair DNA damage or to eliminate the cells damaged beyond repair. One of these mechanisms is nucleotide excision repair (NER) which is the major repair pathway responsible for removing a wide variety of bulky DNA lesions. Deficiency, or mutation, in one or several of the NER repair proteins is responsible for many diseases, including cancer. Prokaryotic NER involves only three proteins to recognize and incise a damaged site, while eukaryotic NER …

Impact Of Epigallocatechin-3-Gallate (Egcg), A Broad-Spectrum Anti-Inflammatory, In Controlling Intestinal Factors Contributing To Inflammatory Bowel Disease., Gerald Wayne Dryden, Jr.

Electronic Theses and Dissertations

This dissertation explores the role of epigallocatechin-3-gallate (EGCG), as a potential treatment for patients with inflammatory bowel disease (IBD). IBD is a common disorder that causes a great deal of suffering. Our understanding of the etiologies, pathogenic mechanisms, and treatment targets continues to evolve. Many new therapeutic targets are making their way through the pharmaceutical pipelines. However, not all patients benefit from these therapies. EGCG has long been studied as an anti-cancer agent. Most of our understanding of this compound comes from the oncologic literature. As the pathways of oncology and inflammation converge, new lessons can be taken from the …

Role Of Microrna-21 In Atherogenesis., Rihab Hamed-Berair

Electronic Theses and Dissertations

MicroRNA-21 (miR-21) is an evolutionarily conserved microRNA, abundant in most cardiovascular tissues. It has been implicated in the pathogenesis of several cardiovascular diseases including restenosis, myocardial infarction, and heart failure. However, little is known about the contribution of miR-21 in atherosclerosis. My data show that expression of miR-21 is increased by >1.5-fold in murine atherosclerotic lesions and by 1.5-2.0-fold in the macrophages of Western diet (WD)-fed LDLR-KO mice (for 12-20 weeks). In vitro, LDL, oxidized LDL, acetylated LDL and LPS induced miR-21 by 2-4-fold and down-regulated its target protein, PDCD4, in bone marrow-derived macrophages. Basally, macrophages isolated from miR-21-KO …

The Influence Of Mir-99a On Mtor Signaling Regulation In Colorectal Cancer Cell Lines., Jonathan Rice

Electronic Theses and Dissertations

Colorectal cancer (CRC) is the third most common cancer worldwide and the fourth most common cause of death. These are staggering statistics for a disease that can essentially be cured if caught early and the pathology is favorable to therapeutic intervention. There is currently a drastic decrease in five year survival as the cancer stage increases from locally confined disease to metastatic disease. These statistics suggest that although some strides have been made with colon cancer screening and early intervention, there is still much room for improvement in both screening and treatment of CRC. One of the pathways that have …

Role Of Phosphodiesterase-4 In Alcohol-Induced Organ Injury., Diana Veronica Avila

Electronic Theses and Dissertations

Alcoholic liver disease (ALD) remains a leading cause of death from liver disease in the U.S., and there is still no FDA-approved therapy. Alcohol metabolism leads to generation of free radicals and oxidative stress with a resultant formation of lipid peroxidation products, which, in turn, contribute to the development of ALD. Alcohol induced hepatic steatosis is the earliest and most frequent manifestation of ALD and a significant risk factor for progressive liver disease. Cyclic adenosine monophosphate (cAMP) signaling has been shown to significantly regulate lipid metabolism. Moreover, agents that increase cAMP have been shown to effectively mitigate oxidative stress both …

Strategies Of Balancing: Regulation Of Posture As A Complex Phenomenon, Allison Leich Hilbun

Electronic Theses and Dissertations

The complexity of the interface between the muscular system and the nervous system is still elusive. We investigated how the neuromuscular system functions and how it is influenced by various perturbations. Postural stability was selected as the model system, because this system provides complex output, which could indicate underlying mechanisms and feedback loops of the neuromuscular system. We hypothesized that aging, physical pain, and mental and physical perturbations affect balancing strategy, and based on these observations, we constructed a model that simulates many aspects of the neuromuscular system. Our results show that aging changes the control strategy of balancing from …

Cell-Based Therapies For Ischemic Cardiomyopathy : Investigations Of Intramyocardial Retention And Safety Of High Dose Intracoronary Delivery Of C-Kit Positive Cardiac Progenitor Cells, And Therapeutic Utility Of A Novel Population Of Cardiac Mesenchymal Stem Cells Expressing Stage-Specific Embryonic Antigen-3 (Ssea-3)., Matthew C. L. Keith

Electronic Theses and Dissertations

Over the last decade attempts at reducing morbidity and mortality of patients with chronic heart failure have been made via the development and implementation of novel cell based therapies. Substantial advances in cell based therapies with indications of efficacy have been shown along with a robust safety profile. Despite these advances, there is a substantial unmet need for novel therapies, specifically addressing repair and regeneration of the damaged or lost myocardium and its vasculature. Accordingly, cardiac cell-based therapies have gained attention. Various cell-types have been utilized, including bone marrow-derived mononuclear cells, bone marrow-derived mesenchymal stem cells, mobilized CD34⁺ cells, …

Microrna-186 And Metastatic Prostate Cancer., Dominique Zilpha Jones

Electronic Theses and Dissertations

MicroRNA (miR) dysregulation alters cancer-associated gene expression, which contributes to cancer pathogenesis. For example, miR-186 over expression lead to enhanced proliferation and migration in pancreatic cancer cell models. However, the role of miR-186 in prostate cancer (PCa) remains controversial. Previously, miR-186-5p was up-regulated in PCa patient serum (stage III/IV) compared to controls. Furthermore, miR-186-5p was up-regulated in metastatic PCa (PC-3, MDA PCa 2b, LNCaP) relative to normal prostate epithelial cells (RWPE1). We hypothesized miR-186 inhibition will reduce aggressive PCa using metastatic cell models. To test this, we evaluated whether miR-186-5p inhibition would reduce aggressive PCa behavior and overexpression induce malignant …

Porphyromonas Gingivalis Gingipains Induce A Pro-Inflammatory Extracellular Microenvironment : The Role Of Par-2 And Fibronectin., Jeffrey S. Marschall

Electronic Theses and Dissertations

Periodontitis is a chronic inflammatory disease that is characterized by severe tissue destruction of the gingiva and other tooth supporting structures; if left untreated, tooth loss and disintegration of the alveolar bone occurs. This chronic inflammatory state has been linked to other systemic diseases such as cardiovascular disease, diabetes, rheumatoid arthritis, and Alzheimer’s disease. Porphyromonas gingivalis is the major pathogenic microbe in periodontitis. The main virulence factors of P. gingivalis are the Arg-aa and Lys-aa gingipains, which are proteolytic enzymes implicated in a plethora of activities that allow P. gingivalis to subvert the human immune system in the oral cavity …

Abin1 In The Pathogenesis Of Glomerulonephritis And The Novel Polocyte-Neutrophil Proinflammatory Axis., Erik Anderson Korte

Electronic Theses and Dissertations

Glomerulonephritis (GN) is the most common cause of end-stage renal disease worldwide and is characterized by deposition of immune complex, inflammation, proteinuria and podocyte damage. Immunosuppressive therapy is effective in less than 50% of patients, indicating that immunological activity is not the only relevant cause of kidney injury. While methods have been described for neutrophil-mediated immune activation, specific glomerular mechanisms for recruitment of neutrophils and development of GN have not been determined. Here I present a pathogenic mechanism for the development of GN involving a novel podocyte-neutrophil axis and reveal the importance of glomerular NF-κB inhibition by the ubiquitin binding …

Acrolein Is A Critical Mediator Of Alcohol-Induced Liver And Intestinal Injury In Alcoholic Liver Disease., Wei-Yang (Jeremy) Chen

Electronic Theses and Dissertations

Alcohol consumption can cause alcoholic liver disease (ALD), which remains a major cause of morbidity and mortality in the United States. Chronic alcohol consumption causes a pro-oxidant environment in the liver and increases hepatic lipid peroxidation. Acrolein is the most reactive and toxic aldehyde generated through lipid peroxidation. Acrolein forms protein adducts and triggers endoplasmic reticulum (ER) stress and hepatocyte apoptosis, which are recognized etiologic factors in ALD. Several studies have established the critical role of the gut-liver axis in ALD pathogenesis, wherein alcohol-induced gut barrier dysfunction contributes to liver injury. This study investigates, in vitro and in vivo, the …

The Mauc Gene Encodes A Versatile Signal Sequence And Redox Protein That Can Be Utilized In Native And Non-Native Protein Expression And Electron Trnasfer Systems, Brian Dow

Electronic Theses and Dissertations

The redox-active type 1 copper site of amicyanin is composed of a single copper ion that is coordinated by two histidines, a methionine, and a cysteine residue. This redox site has a potential of +265 mV at pH7.5. Over ten angstroms away from the copper site resides a tryptophan residue whose fluorescence is quenched by the copper. The effects of the tryptophan on the electron transfer (ET) properties were investigated by site-directed mutagenesis. Lessons learned about the hydrogen bonding network of amicyanin from the aforementioned study were attempted to be used as a model to increase the stability of another …

Structural And Functional Characterization Of Enzymes Of A Novel Group Of Tryptophylquinone Cofactor Containing Oxidases, Esha Sehanobish

Electronic Theses and Dissertations

Protein-derived cofactors are redox and catalytic centers that are generally formed by the posttranslational modifications of one or more amino acids. An important class of these cofactors are the quinones derived from tyrosine and tryptophan. Amongst redox proteins, it has been known till now that oxidases either contain a flavin or a tyrosylquinone cofactor, whereas tryptophylquinone ones are present within the dehydrogenases. In recent times, oxidases from a marine bacterium, Marinomonas mediterranea, have been shown to possess the latter. This study involves the characterization of two such proteins, lysine-?-oxidase (LodA) and glycine oxidase (GoxA). They have been reported to contain …

Role Of Klf8-Cxcr4 Signaling In Breast Cancer Metastasis, Debarati Mukherjee

Electronic Theses and Dissertations

Krüppel-like factor 8 (KLF8) has been strongly implicated in breast cancer metastasis. However, the underlying mechanisms remain largely unknown. In this study we report a novel signaling from KLF8 to C-X-C cytokine receptor type 4 (CXCR4) in breast cancer. Overexpression of KLF8 in MCF-10A cells induced CXCR4 expression at both mRNA and protein levels. This induction was well correlated with increased Boyden chamber migration, matrigel invasion and transendothelial migration (TEM) of the cells towards the ligand CXCL12. On the other hand, knockdown of KLF8 in MDA-MB-231 cells reduced CXCR4 expression associated with decreased cell migration, invasion and TEM towards CXCL12. …

Novel Cellular Targets Of Aspirin In Chemoprevention Studies On P53, G6pd And C-Myc, Guoqiang Ai

Electronic Theses and Dissertations

Background

Aspirin has generated a significant interest in recent years as a potential chemopreventive agent supported by strong evidence from epidemiological data; however, the mechanisms are not well understood. The objective of this dissertation is to identify novel cyclooxygenase (COX)-independent pathways by which aspirin exerts its anticancer effects in epithelial cancer cell lines. We investigated the effect of aspirin on p53, glucose 6-phosphate dehydrogenase (G6PD), and c-Myc, all of which are known to play a major role in cancer development. p53 is a tumor suppressor protein, often mutated in cancers causing its inactivation. Expression of G6PD is elevated in many …

Biophysical Sources Of 1/F Noises In Neurological Tissue, Alan Paris

Electronic Theses and Dissertations

High levels of random noise are a defining characteristic of neurological signals at all levels, from individual neurons up to electroencephalograms (EEG). These random signals degrade the performance of many methods of neuroengineering and medical neuroscience. Understanding this noise also is essential for applications such as real-time brain-computer interfaces (BCIs), which must make accurate control decisions from very short data epochs. The major type of neurological noise is of the so-called 1/f-type, whose origins and statistical nature has remained unexplained for decades. This research provides the first simple explanation of 1/f-type neurological noise based on biophysical fundamentals. In addition, noise …

The Role Of Sod1 Acetylation In Neurodegeneration, Michael Kaliszewski

Electronic Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder affecting motor neurons. Cu, Zn superoxide dismutase (SOD1), a cytoplasmic free radical scavenging enzyme, is mutated in familial ALS (fALS) and post-translational modification of the wild-type protein has been associated with sporadic ALS (sALS). Proteomic studies indicate that SOD1 is acetylated at Lys123; however, the role of this modification remains unknown. To investigate its function, we generated antibodies for Lys123-acetylated SOD1 (Ac-K123 SOD1). Sod1 deletion in Sod1-/- mice, K123 mutation, or preabsorption with Ac-K123 peptide suppressed immunoreactivity, confirming antibody specificity. In the normal central nervous system, Ac-K123 SOD1 maps to glutamatergic …