Life Sciences Commons^™

Functional Characterization Of Lt-Hsc Metabolic Activity Dependent On Ahr Activity, Everett Tate

Theses and Dissertations

The cells of the immune system are descended from multipotent hematopoietic stem cells (HSCs) that emerge during development. Multipotency means that a single progenitor HSC can differentiate into any cell of the immune system. HSCs are required to do this for the lifetime of the organism through a process called self-renewal, and as such, any perturbation during development or in the bone marrow can have a trickle-down effect, affecting the self-renewal capacity or ability to terminally differentiate. The aryl hydrocarbon receptor (AHR) is a known regulator of HSCs. The AHR is a transcription factor required for the detoxification of numerous …

Cholesterol: A Possible Mediator Of Apoe Risk For Alzheimer's Disease, Michelle Marie Dunk

Theses and Dissertations

Despite the well-established link between the ε4 allele of the apolipoprotein E (APOE) gene and AD, the underlying mechanisms that mediate the risk of developing AD remain elusive. Literature on the role of APOE in cholesterol metabolism suggests that blood cholesterol may be a key factor in the development of AD pathology. Current study aims to investigate whether total cholesterol differs by APOE status and whether this relationship is predictive of AD diagnosis and its biomarkers. Baseline total cholesterol, APOE status, AD diagnosis, global cognitive function, brain Aβ, plasma Aβ40 and Aβ42, and cerebrospinal fluid (CSF) Aβ, tau, and phosphorylated …

Characterization Of Plasmids Harbored By Vibrio Cholerae Isolates Endemic To The Rio Grande Delta, Viviana Trevino

Theses and Dissertations

Cholera is a diarrheal disease responsible for considerable morbidity and mortality globally. Epidemics along the Rio Grande Delta were reported during the 1850s, and the etiological agent Vibrio cholerae, remains endemic, thus presenting a unique opportunity for a study of historical and biological relevance. V. cholerae strains were isolated from two locations: the Rio Grande River under a bridge linking Brownsville to Matamoros (site 21) and where the river empties into the Gulf of Mexico (site 42). Two strains from site 21, and one from site 42 were selected to isolate, subclone, sequence, assemble and annotate extra-chromosomal elements. Results …

Role Of Regulatory T Cells In The Development And Progression Of Lyme Disease In Balb/C Mice, Kaitlyn Nielsen

Theses and Dissertations

Lyme disease, caused by Borrelia burgdorferi, is an increasingly important public health concern, with tens of thousands of new cases being diagnosed each year, even in previously non-endemic areas. It is known that symptoms of Lyme disease are caused by an inflammatory immune response initiated to aid in clearance of the pathogen. Left unchecked, these inflammatory responses can potentially increase tissue damage, leading to increased disease severity. Mechanisms responsible for the control of the inflammatory response to infection with B. burgdorferi are not entirely understood. Evidence exists that regulatory T (Treg) cells, a population of Foxp3-expressing CD4+ T cells known …

Investigating The Contribution Of Instance-Reliant Learning In Visuomotor Adaptation And Its Generalization, Shancheng Bao

Theses and Dissertations

Motor adaptation has been of great interest in the past two decades as it reflects how movement skills are acquired and consolidated by the nervous system. In our recent studies, instance-reliant learning is considered as an essential component of visuomotor adaptation, since it plays a unique role in fast and automatized control of movement output. The goal of this dissertation is to investigate the nature of instance-reliant learning on two aspects: to determine the differential contributions of algorithmic learning and instance-reliant learning to visuomotor adaptation; and to determine the nature of movement instance involved in visuomotor adaptation and its generalization …

Temperature Influence On Insecticide Resistance In Aedes Aegypti And Aedes Albopictus Mosquitoes From South Texas, Wendy Soledad Salinas

Theses and Dissertations

Aedes aegypti and Aedes albopictus are vectors for several emerging arboviruses including Zika, chikungunya and dengue. Both mosquitoes are found along the Rio Grande River in South Texas, along the border between Mexico and the United States of America. These mosquito species typically reside near human settlements. A preventative measure public health official use to help halt the spread of diseases is by controlling vector population with the use of insecticides, but as temperature vary, and with the constant exposure to commonly used insecticides, mosquitoes from South Texas may be developing a resistance to the insecticides. Resistance to insecticides may …

An In Silico Study Of G Protein-Coupled-Receptor Activation, Specifically In The Corticotropin Releasing Factor Receptor And The Glucagon-Like Peptide Receptor, Nicolas Angelo Scorese

Theses and Dissertations

The drug discovery process is an extremely long and expensive process that modern computational methods help to alleviate. Through the use of computational methods, we provide information and insight into the activation methods of class B GPCRs so that future drugs can be developed to have less side effects. The first study focuses on the corticotropin releasing factor receptor, which is a good drug target for anxiety and depression. A mechanism of activation was theorized which focuses less on molecular switches (as has been the focus of several papers) and more on large scale conformation at the intracellular region of …

Quantitative Evaluation Of Geared Manual Wheelchair Mobility In Individuals With Spinal Cord Injury: An Integrative Approach, Omid Jahanian

Theses and Dissertations

The purpose of this dissertation is to quantify the effects of using geared wheelchair wheels on upper extremity biomechanics and energy expenditure during functional mobility tasks in individuals with spinal cord injury (SCI). The effects of using geared wheels on hand-rim biomechanics, glenohumeral joint dynamics, and shoulder muscle activity were investigated during manual wheelchair propulsion over tiled and carpeted level-floors and up a ramp in low gear (1.5:1) and standard gear (1:1) conditions. The results for the hand-rim biomechanics indicated that regardless of the terrain, using the geared wheels in the low gear condition significantly decreased the propulsion speed, stroke …

Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus

Theses and Dissertations

Markers of cognitive impairment are needed to distinguish normal from pathological aging prior to the onset of clinical symptomology to improve Alzheimer’s disease (AD) treatment or prevention efforts. AD pathology is believed to develop years or even decades prior to diagnosis in medial temporal lobe subregions that provide input to the hippocampus (Braak & Braak, 1991), disrupting the ability of the hippocampus to bind individual elements of an experience to form cohesive memory representations. Eye movement behavior is a sensitive index of learning and effects of memory on eye movements have been shown to emerge rapidly (within 500-750ms of stimuli …

Memory-Based Viewing: A Potential Marker Of Pathological Aging, Jenna Blujus

Theses and Dissertations

Markers of cognitive impairment are needed to distinguish normal from pathological aging prior to the onset of clinical symptomology to improve Alzheimer’s disease (AD) treatment or prevention efforts. AD pathology is believed to develop years or even decades prior to diagnosis in medial temporal lobe subregions that provide input to the hippocampus (Braak & Braak, 1991), disrupting the ability of the hippocampus to bind individual elements of an experience to form cohesive memory representations. Eye movement behavior is a sensitive index of learning and effects of memory on eye movements have been shown to emerge rapidly (within 500-750ms of stimuli …

The Regulation Of Skeletal Muscle Fatigue During The Progression Of Cancer Cachexia, Brandon N. Vanderveen

Theses and Dissertations

Cachexia is the unintentional loss of body weight secondary to chronic disease and is prevalent is roughly 50% of cancer patients. The loss of body weight and skeletal muscle mass is reduced functional capacity associated with reduced life quality. The etiology of cachexia is multimodal and complex; however, cachexia has been linked to several systemic (e.g. chronic inflammation, hypogonadism, anemia, insulin resistance) and behavioral (e.g. anorexia, inactivity) changes that can compound to accelerate muscle mass and body weight loss. While several inflammatory cytokines are associated with cachexia’s disease progression, our laboratory has established that Interleukin-6 (IL-6) is a key regulator …

Deciphering The Consequences Of Yolk Testosterone Metabolism In Birds, Nicole A. Campbell

Theses and Dissertations

Maternal steroids transferred to eggs can elicit permanent effects on various aspects of offspring phenotype. Although, testosterone was thought to be a key mediator of maternal effects in birds, we now know that vertebrate embryos actively regulate their exposure to maternal testosterone through steroid metabolism, suggesting testosterone metabolites may elicit the observed phenotypic effects. To address the role steroid metabolism plays in mediating yolk testosterone effects, we used European starling (Sturnus vulgaris) eggs to characterize the timing of testosterone metabolism and determine whether etiocholanolone, a prominent testosterone metabolite in avian embryos, is capable of influencing early embryonic development. Tritiated testosterone …

Impact Of A Single Injury Prevention Instructional Session On The Incidence Of Injury Among U.S. Army Rotc Cadets, Joshua Wooldridge

Theses and Dissertations

Background: Musculoskeletal injuries are the leading health concern for the United States Army. These injuries are the third leading cause of hospitalizations for Army service members and the primary cause for the majority of service-connect disability discharges. Over 80% of musculoskeletal injuries are overuse injuries caused by physical training. The Joint Services Physical Training Injury Prevention Work Group considers education to be a mandatory component of all injury prevention efforts; however, little military research has investigated the impact of education as a primary intervention. Objective: To examine the effect of an injury prevention education class on the incidence of injuries …

Mining For Specialized Metabolism Genes In Red Sea Brine Pool Prokaryotic Metagenomes For Antibacterial And Anticancer Activities, Laila Ziko

Theses and Dissertations

Antibiotic and anticancer drug resistance are current global health threats, thus new antibiotics and anticancer agents are required to treat the strains and cancers that are currently untreatable with the available drug spectrum. One way to search for new chemotherapeutics is to search nature, particularly metagenomes of un-cultured microbial communities. A subset of specialized metabolites (SMs) produced by microbes confer activities of pharmaceutical importance, such as antibacterial and anticancer effects, and are coded by specialized metabolism gene clusters (SMGCs) in the organisms’ genomes. We aimed to search for SMGCs in the metagenomes of Red Sea brine microbial communities by employing …

Illumination Of The Golgi Apparatus Of Pathogenic And Nonpathogenic Naegleria Species, Tyler M. Poe

Theses and Dissertations

In this study, Naegleria fowleri, a pathogenic amoeba and the causative agent of Primary Amebic Meningoencephalitis (PAM), was utilized to determine the presence or absence of classically conserved Golgi molecules featured in the expression of a Golgi apparatus. Previous studies concluded no Golgi expression via light microscopy and transmission electron microscopy, but a recent report on Naegleria gruberi indicated the presence of dispersed Golgi tubules. Non-pathogenic species of the Naegleria genus such as Naegleria gruberi 30540 and Naegleria lovaniensis 30569 were utilized in Western immunoblot analysis compared to reduced whole-cell lysate proteins of two strains of N. fowleri and …

Structure-Activity Relationship Studies Of Synthetic Cathinones And Related Agents, Rachel A. Davies

Theses and Dissertations

Synthetic cathinones and related agents represent an international drug abuse problem, and at the same time an important class of clinically useful compounds. Structure-activity relationship studies are needed to elucidate molecular features underlying the pharmacology of these agents. Illicit methcathinone (i.e., MCAT), the prototype of the synthetic cathinone class, exists as a racemic mixture. Though the differences in potency and target selectivity between the positional and optical isomers of synthetic cathinones and related agents have been demonstrated to have important implications for abuse and therapeutic potential, the two MCAT isomers have never been directly compared at their molecular targets: the …

Translational Insights Into The Genetic Etiology Of Mental Health Disorders: Examining Risk Factor Models, Neuroimaging, And Current Dissemination Practices, Jessica L. Bourdon

Theses and Dissertations

Psychiatric genetics is a basic science field that has potential for practical application and effective translation. To date, translational frameworks utilized by this field have been linear (e.g., sequential) in nature, focusing on molecular genetic information. It is proposed that non-linear (e.g., socio-ecological) frameworks are a better way to immediately translate non-molecular genetic information. This dissertation explored the translation of psychiatric genetic information in two ways. First, a survey was sent to academic stakeholders to assess the state of the science regarding the translation of genetic information to the clinical care of mental health disorders. Findings from this indicate a …

Targeting Sphingosine Kinase 2 As A Treatment For Cholangiocarcinoma, Anthony D. Stillman

Theses and Dissertations

Cholangiocarcinoma (CCA) has a high mortality rate and its occurrence is rising. This increase prompts the need for improved CCA treatments. Studies have suggested that CCA is highly reliant on the sphingosine-1-phosphate-receptor-2 (S1PR2) and sphingosine kinase 2 (SphK2). Recently, a competitive SphK2 inhibitor, ABC294640, has been approved for clinical trial. ABC294640 has the potential to treat CCA, which is support by a phase I clinical study that was able to temporarily treat a patient suffering from metastasized CCA with ABC294640. To determine the viability of ABC294640 as a treatment for CCA, this study focused on determining the effects of ABC294640 …

Spag17 Deficiency Impairs Neuronal Cell Differentiation In Developing Brain, Olivia J. Choi

Theses and Dissertations

The development of the nervous system is a multi-level, time-sensitive process that relies heavily on cell differentiation. However, the molecular mechanisms that control brain development remain poorly understood. We generated a knockout (KO) mouse for the cilia associated gene Spag17. These animals develop hydrocephalus and enlarged ventricles consistent with the role of Spag17 in the motility of ependymal cilia. However, other phenotypes that cannot be explained by this role were also present. Recently, a mutation in Spag17 has been associated with brain malformations and severe intellectual disability in humans. Therefore, we hypothesized that Spag17 plays a crucial role in …

Regorafenib Enhances Lethality Of Sildenafil And Curcumin In Colorectal Cancer Cells, Kervin Benjamin Owusu

Theses and Dissertations

In the United States, more than 130,000 people will be diagnosed with colorectal cancer (CRC) each year and an estimated 50,000 people will die from the disease. Standard of care (SOC) therapies for CRC combine multiple cytotoxic chemotherapeutic drugs. These combinations have varying degrees of effectiveness and can often result in significant patient morbidity. For second recurrence patients, the multi-kinase inhibitor, regorafenib, is an approved agent, but is often poorly tolerated at current doses. In the current study, we propose to develop therapeutic regime of combining agents with modest toxicity profiles: curcumin and sildenafil with regorafenib. Using clinically achievable enterohepatic …

Eralpha Isoforms Modulate The Tumorigenicity Of 24r,25(Oh)2d3 In Estrogen-Responsive Cancer, Anjali Verma

Theses and Dissertations

Over 200,000 cases of breast cancer are diagnosed every year. Nearly 20% of these patients supplement their diets with some form of vitamin D. This high frequency of vitamin D supplement use may be due in part to research suggesting that cancer patients with higher serum vitamin D₃ levels have better prognoses than patients with low serum vitamin D_3. However, double-blind clinical trials on the efficacy of vitamin D₃ supplementation in breast cancer have been inconclusive. A recent meta-analysis showed evidence of reduced cancer recurrence in patients taking vitamin D₃ supplements who had ‘estrogen receptor positive’ …

Chemical Characterization Of Pseudognaphalium Obtusifolium By Gas Chromatography - Mass Spectrometry (Gc-Ms) To Assess Potential Therapeutic Phytochemicals And Toxicological Concerns Using Simulated Use Conditions, Regina Ballentine

Theses and Dissertations

Chemical Characterization of Pseudognaphalium obtusifolium by Gas Chromatography – Mass Spectrometry (GC-MS) to Assess Potential Therapeutic Phytochemicals and Toxicological Concerns Using Simulated Use Conditions

By Regina Ballentine

Virginia Commonwealth University, 2019

Director: Sarah C. Rutan, Professor, Department of Chemistry

Currently, there is an increasing demand for natural therapies and herbal products to treat various ailments. It is generally believed that natural therapies have fewer side-effects than traditional western medicine; however, they are often used in different strengths and formulations without consistency of the levels of target compounds or knowledge about toxicity. Due to this growing trend, a comprehensive chemical evaluation …

Cellular Mechanisms By Which Alcohol Promotes Hiv Protease Inhibitor-Induced Hepatotoxicity, Michael Hinton

Theses and Dissertations

CELLULAR MECHANISMS BY WHICH ALCOHOL PROMOTES HIV PROTEASE INHIBITOR-INDUCED HEPATOTOXICITY

Michael Hinton, B.S.

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University

Virginia Commonwealth University, 2019

Major Director: Huiping Zhou

Professor, Department of Microbiology and Immunology

The development of highly-active-antiretroviral therapy(HAART) has allowed management of HIV and extended the lives of those infected. Alcohol abuse, which is very common in HIV-1 infected patients, is one of the most important co-morbid risk factors for liver injury and has been associated with the occurrence of serious metabolic syndrome and subsequent discontinuation …

Genome-Wide Systems Genetics Of Alcohol Consumption And Dependence, Kristin Mignogna

Theses and Dissertations

Widely effective treatment for alcohol use disorder is not yet available, because the exact biological mechanisms that underlie this disorder are not completely understood. One way to gain a better understanding of these mechanisms is to examine the genetic frameworks that contribute to the risk for developing this disorder. This dissertation examines genetic association data in combination with gene expression networks in the brain to identify functional groups of genes associated with alcohol consumption and dependence.

The first study took advantage of the behavioral complexity of human samples, and experimental capabilities provided by mouse models, by co-analyzing gene expression networks …

Embryonic Stem Cell-Derived Exosomes Increase The Antiproliferative Activity Of Doxorubicin In Breast Cancer, Alexander M. Hirsch

Theses and Dissertations

The field of cancer research has grown immensely in recent decades and has led to a better understanding of the causes of the disease, as well as greatly improved treatment for various types of cancers, especially breast cancer. One of the most effective treatments involves the chemotherapeutic drug doxorubicin (DOX). DOX is an effective tool against all types of breast cancer, especially against triple negative breast cancer. However, DOX causes adverse side effects that include damage to the heart and skeletal muscle, particularly above specific cumulative doses. Recent evidence suggests that embryonic stem cell-derived (ES) exosomes, nanoscale extracellular vesicles that …

The Role Of Sphingosine Kinase 2 In Alcoholic Liver Disease, Eric K. Kwong

Theses and Dissertations

Alcoholic liver disease (ALD) is one of the most common liver diseases worldwide characterized by the accumulation of lipids within the liver, inflammation and the possibility of progressing to cirrhosis and liver failure. More importantly, there are currently no effective treatments for ALD and liver transplantation remains the only therapeutic option for end-stage liver disease. Previous studies have shown that ALD is a result of a combination of endoplasmic reticulum (ER) stress, lipid metabolism dysregulation and inflammation. It has been previously reported that alcohol disrupts gut microbiota homeostasis and causes increased endotoxins that contribute to the pathology of ALD. However, …

Diuretic And Natriuretic Activity Of Faah Inhibition In The Renal Medulla: A Proposed Role Of Palmitoylethanolamide And Its Regulation By Renal Medullary Interstitial Cells, Sara Dempsey

Theses and Dissertations

Hypertension is a critical public health issue worldwide, and in the United States, it is the leading cause of heart disease, stroke, and kidney failure, contributing to more than 1,100 deaths per day. It is proposed that the renal medulla combats increased blood pressure by releasing a neutral lipid from the lipid droplets of medullary interstitial cells, termed medullipin, which induces diuresis- natriuresis and vasodepression. The renal medulla is enriched with fatty acid lipid ethanolamides including the endocannabinoid anandamide (AEA), palmitoylethanolamide (PEA), and oleoylethanolamide (OEA), along with their primary hydrolyzing enzyme fatty acid amide hydrolase (FAAH). Our lab is investigating …