Medicine and Health Sciences Commons^™

Selective Targeting Of Microglia By Quantum Dots And Green Synthesis Of Metal Organic Biohybrids; Applications In Dynamic Cell And Assay Systems, Navya Uppu

Doctoral Dissertations

Neurological disorders are the leading cause of physical and cognitive disability across the globe, currently affecting approximately 15% of the worldwide population. Part of the glioma microenvironment are microglia, resident immune cells of the CNS that were thought to be involved in the pathogenesis of diverse neurodegenerative diseases. Though it remains uncertain what triggers microglial activation in these disorders, targeting and tracking microglial functions using nanotools like Quantum Dots (QDs) could help us elucidate them in such neurological diseases. This research focuses on the comparative study of different QDs formulations and their selective uptake by brain microglia in primary cultures …

Role Of Fat Content On The Structure And Function Of Human Skeletal Muscle, Joseph A. Gordon Iii

Doctoral Dissertations

Muscle size does not fully explain variations in muscle strength. Fat content has been implicated in muscle weakness, though this relationship remains unclear. The relationship between fat and strength may vary between scales (e.g., cellular, organ, and organism). The goal of this dissertation was to clarify the role of fat in the structure and function of muscle using in vitro and in vivo techniques across multiple scales in adults 21-45 years old. Study 1 tested the agreement of intramyocellular lipid (IMCL) content between oil red o (ORO) and magnetic resonance spectroscopy (MRS) techniques. These measures of IMCL were also compared …

Utilizing Ultra-Performance Chromatography High-Resolution Mass Spectrometry To Investigate Fatty Acid Mediated Antibiotic Tolerance, Brittni Woodall

Doctoral Dissertations

The lipid membrane is the first component necessary to sustain life. To maintain homeostasis, segregate cellular machinery, provide protection from the environment, and reproduce, an organism must establish a boundary in which the processes can occur. Throughout the last two decades, research has propelled our knowledge of lipid membranes much beyond original hypotheses. Once thought of to be static and uniform, the understanding of the lipid membrane has evolved to encompass a structure that is responsive, unique, and intricately constructed by the organism itself. By chance or by choice, organisms adapt the lipid membrane according to the environment for which …

Mechanisms Of Cigarette Smoke-Induced Mitochondrial Dysfunction In Striated Muscle And Aorta, Stephen T. Decker

Doctoral Dissertations

Cigarette Smoke is a significant cause of morbidity and mortality in the United States, accounting for over 480,000 annual deaths. Of these deaths, the most common cause of mortality in chronic smokers is cardiometabolic diseases. Likewise, a significant portion of smokers experience some form of cardiac, vascular, or metabolic dysfunction throughout their lifetime. More specifically, smoking is shown to induce mitochondrial dysfunction in these tissues, causing an increase in oxidative damage and poor overall health. However, despite the advances in the health outcomes related to cigarette smoke exposure, the mechanisms underlying mitochondrial dysfunction in striated muscle and the vasculature remain …

Frontiers In The Self-Assembly Of Charged Macromolecules, Khatcher O. Margossian

Doctoral Dissertations

The self-assembly of charged macromolecules forms the basis of all life on earth. From the synthesis and replication of nucleic acids, to the association of DNA to chromatin, to the targeting of RNA to various cellular compartments, to the astonishingly consistent folding of proteins, all life depends on the physics of the organization and dynamics of charged polymers. In this dissertation, I address several of the newest challenges in the assembly of these types of materials. First, I describe the exciting new physics of the complexation between polyzwitterions and polyelectrolytes. These materials open new questions and possibilities within the context …

Contributions Of Asymmetry And Instability To Transfer And Retention Following Locomotor Adaptation, Daniel L. Gregory

Doctoral Dissertations

Gait asymmetry resulting from neurological injury is more costly and less stable than healthy gait. Split-belt treadmills, which drive limbs at different speeds, lead to spatial and temporal gait asymmetries, and perturb walking balance, have been used to study locomotor adaptability and learning related to asymmetry and stability. This knowledge may be leveraged to design more effective rehabilitation protocols. In experiment 1, we asked how constraining stride-rates away from preferred during split-belt walking influences learning revealed in a retention test. We found that constraints to stride rate during asymmetric walking uncovered the capacity to leverage redundant degrees-of-freedom for walking control, …

Controlling Myosin’S Function Via Interactions Between The Substrate And The Active Site, Mike K. Woodward

Doctoral Dissertations

Molecular motors, such as myosin, have evolved to transduce chemical energy from ATP into mechanical work to drive essential cellular processes, from muscle contraction to vesicular transport. Dysfunction in these motors is a root cause of many pathologies necessitating the application of intrinsic control over molecular motor function. We hypothesized that altering the myosin’s energy substrate via minor positional changes to the triphosphate portion of the molecule will allow us to control the protein and affect its in vitro function. We utilized positional isomers of a synthetic non-nucleoside triphosphate, azobenzene triphosphate, and assessed whether myosin’s force- and motion-generating capacity could …

An Evaluation Of Methods To Reduce Inframammary Surface Dose In Prone Breast Irradiation, Seth Alvarado

Doctoral Dissertations

In cases of breast radiation treatments via external beam radiation therapy, the incidence of radiation dermatitis has been reported. In prior studies, this acute radiation side-effect has been correlated with the immobilization devices in cases of prone breast irradiation. They attribute this to the bolus effect that occurs with the interaction of the incident photon beam at different projections causing an increase in measured surface dose. The type of radiation planning technique, and patient positioning during the undertaking of these techniques, have also shown to influence this bolus effect. This study focuses on these factors in treatment planning in order …

The Experiences And Needs Of Individuals With A Variant Of Uncertain Significance (Vus) On Genetic Tests For Hereditary Cancer Syndromes: A Grounded Theory Study, Danielle Gould

Doctoral Dissertations

Background: The use of multigene panel testing for identifying individuals with hereditary cancer susceptibility has expanded in recent years. The number of individuals who have a variant of unknown significance (VUS) result is increasing. However, little is known about the experiences and needs of this group. This study’s purpose was to describe the experiences and needs of individuals with a VUS result by focusing on their experiences in communicating with healthcare providers and family members. Methods: A constructivist grounded theory approach was used. Recruitment took place from January–July 2021 through social media: the Prospective Registry of Multiplex Testing (PROMPT), and …

Changes In Muscle Control And Coordination In Novel Task Learning, Sangsoo Park

Doctoral Dissertations

Learning many daily life motor skills is critical for survival and the quality of living in humans. As children, we develop walking and running patterns to move the body from point A to B without falling, and we learn to grasp a wide variety of objects during activities of daily living. Motor skills can be properly performed by appropriate muscle activations which are controlled by the central nervous system. How does the central nervous system develop and fine-tune its control strategy to learn a new motor skill? The aim of this dissertation was to better understand how human participants alter …

A Computational Study Of Sleep And The Hemispheres Of The Brain, Tera Ashley Glaze

Doctoral Dissertations

"Sleep and sleep cycles have been studied for over a century, and scientists have worked on modeling sleep for nearly as long as computers have existed. Despite this extensive study, sleep still holds many mysteries. Larger and more extensive sleep-wake models have been developed, and the circadian drive has been depicted in numerous fashions, as well as incorporated into scores of studies. With the ever-growing knowledge of sleep comes the need to find more ways to examine, quantify, and define it in the context of the most complex part of the human anatomy -- the brain. Presented here is the …

Extrinsic And Intrinsic Factors In Liver Development, Amrita Palaria

Doctoral Dissertations

Liver is the largest internal organ of the human body. It performs a multitude of functions. Therefore, it is provided with a huge regenerative capacity however, because of the same reason it is also prone to various diseases. Hence, it is essential to understand liver development in order to understand liver regeneration and liver diseases to provide better therapeutic targets and solutions. Liver development is orchestrated by a variety of intrinsic and extrinsic factors. The major focus of this dissertation thesis is to elucidate the role of BMP signals and YY1/VEGFA regulated signals in liver development. Liver organogenesis initiates with …

Foki Vitamin D Receptor Gene Polymorphisms And Metabolic Health In Pregnant Saudi Women, Maysa Alzaim

Doctoral Dissertations

Lifestyles have been dynamically changing in the past few years in Saudi Arabia, and the prevalence of non-communicable diseases (NCDs), such as obesity, diabetes, hypertension, high cholesterol, and other cardiovascular diseases (CVD), is notably increasing. In fact, NCDs are affecting a growing number of people in SA, especially women of childbearing age. Vitamin D deficiency has also become pandemic and a major public health concern among the Saudi population despite the abundance of sunlight. The most vulnerable groups are pregnant women and their newborns. Previous studies have correlated low vitamin D status with a higher risk of adverse short- and …

Sleep, And Its Relation To Non-Motor Deficits In Patients With Cerebellar Ataxia, Akshata Sonni

Doctoral Dissertations

The cerebellum is a highly connected structure, and its involvement in sleep – which is a dynamic process that is modulated by a complex set of neural systems – can come about through a number of neural pathways. We conducted two studies aimed at furthering our understanding of cerebellar involvement in sleep behavior and physiology, as well as measuring the impact of poor sleep on mood and cognition in patients with cerebellar degeneration. First, by means of an online battery including measures of sleep and neuropsychiatric function, we collected data from 176 patients with cerebellar ataxia. We found strong evidence …

Post-Concussion Experiences Of Collegiate Student-Athletes, Kaitlin Iris Singer

Doctoral Dissertations

Sports-related concussions are a major public health concern affecting a significant number of collegiate student-athletes. Medical and public health research has addressed every aspect of concussion management processes including concussion education, medical diagnosis, recovery, and returning to sport and classroom. This research has led to several best-practices for concussion management. Since 2010, the NCAA has mandated that its member institutions maintain concussion management policies and procedures. However, the current recommendations, based primarily on medical research, have been found in quantitative studies of the behaviors and practices of athletic trainers, coaches, and student-athletes to be ineffective. To date, no studies have …

Elucidating The Effects Of Metabolic State On Nanoparticle Distribution In Mice And In Vitro Uptake, Kevin James Quigley

Doctoral Dissertations

Since almost 70% of the U.S. population over 20 years old is overweight and 30% is obese, with much of the western world following suit, many patients that will potentially be administered circulating nanoparticles designed to localize to tumors and avoid non-target areas will have significant amounts of white adipose tissue (WAT), enlarged livers, and additional metabolic complications such as type 2 diabetes. However, studies on nanoparticle biodistribution and efficacy take place almost without exception in lean rodents with healthy metabolic states. In this work, I determined the biodistribution of model nanoparticles – neutral filomicelles and polystyrene spheres both carrying …

Inhibition Of The Pi3k/Akt Signaling Pathway Increases Efficacy Of Doxorubicin And Its Derivative Ad198 In Bladder And Oral Cancers, Dmitriy Smolensky

Doctoral Dissertations

Doxorubicin (Dox) is a successful chemotherapy to treat various cancers, including bladder and oral cancers. Many patients initially respond to Dox-based regimens, however often cancers become resistant. A novel derivatives of Dox, e.g. N-benzyladriamycin-14-valerate (AD198), have been developed to overcome Dox-induced drug resistance and cardiotoxicity. The purpose of this thesis was to determine the efficacy of AD198 and Dox in bladder and oral cancers in vitro.

Part-I of this dissertation focuses on the bladder cancer, including discussing risk factors, diagnosis, staging, and current treatment options, following by a description of altered molecular mechanisms responsible cancer progression. This section also focuses …

The Chemopreventive Effect Of Polymethoxyflavones: Targeting The Colorectal Cancer Stem Cells, Fei Xu

Doctoral Dissertations

Among all the cancers, the death rate of colorectal cancer is one of the highest. Evidence from both murine xenograft model and human trials have shown cancer stem cells (CSCs) are responsible for the initiation, metastasis and recurrence of multiple cancers therefore targeting colorectal CSCs would be a promising chemo-preventive/ therapeutic strategy. Polymethoxyflavones including nobiletin (NBT) and 5-demethylatednobiletin (5DN) are exclusively found in citrus peels and have been shown to have anti-cancer effects. Our previous studies in the biotransformation and tissue distribution of NBT and 5DN have shown that in order to fuller evaluate the biological impact of those two …

Characterization And Development Of Amyloid-Reactive Peptides As Tracers For Quantitative Molecular Imaging, Emily Brooke Martin

Doctoral Dissertations

Amyloidosis is a degenerative protein misfolding disorder that leads to the extracellular accumulation of amyloid deposits containing protein fibrils, heparan sulfate proteoglycans, glycoproteins and apolipoproteins. To date, at least 27 proteins have been identified as components of pathologic amyloid fibrils. In systemic forms of the disease, amyloid deposits can evade the immune system and expand throughout various tissues. As the deposits grow, tissue architecture is disrupted, leading to organ dysfunction and death.

In the US, there are ~3500 newly diagnosed patients with amyloidosis annually. The deposition of light chains as amyloid (AL amyloidosis) is the most common form of visceral …

Elucidating Cellular Signaling Pathways That Contribute To The Immunopathogenesis Of Aplastic Anemia, Christina M. Kuksin

Doctoral Dissertations

Aplastic Anemia is a rare immune mediated bone marrow failure disease that is mediated by autoreactive T cells that cause destruction to the stem, progenitor, and stromal cells in the bone marrow. Because little is known about the etiology of the disease, our lab has developed a major MHC mismatch GVHD model to examine cellular pathways in autoreactive T cells that contribute to disease. We examined three pathways that are important in T cell activation and differentiation and asked if they were important in the development of Aplastic Anemia. First, we were able to show that expression of active PKCθ …

Safety And Immunoreactivity Of A Xenogeneic Dna Plasmid Vaccine Expressing Human Tyrosinase In Tumor-Bearing Horses, Luis Miguel Lembcke Perez Prieto

Doctoral Dissertations

Melanomas are among the most common skin tumors in horses (second only to sarcoids), with prevalence rates reaching as high as 80% in adult gray horses. Despite the wide availability of measures of local control, there are currently no systemic therapies that can effectively prevent spread, or treat metastatic or locally advanced/non-resectable melanoma in horses. A form of gene immunotherapy based on a plasmid DNA construct containing a xenogeneic form of the antigen tyrosinase have been developed and optimized for targeting cancer in both humans and dogs; and have demonstrated significant immunoreactivity and clinical benefit in the treatment of melanocytic …

Growth Regulation Of Pancreatic Cancer Cells And Their Normal Cells Of Origin By Nicotinic Acetylcholine Receptors, Mohammed Hussein Al-Wadei

Doctoral Dissertations

Pancreatic cancer is the fourth leading cause of cancer mortality with a five-year survival rate of less than 5 %. It shows no symptoms until it has reached an advanced stage upon which it has metastasized to distant organs limiting therapeutic options. Several studies have identified smoking, alcohol, diabetes and pancreatitis as risk factors for pancreatic cancer. While smoking is a well-documented risk factor for this malignancy, there still remains a controversy on whether alcohol can act as a risk factor itself or cooperatively enhances the effects of other risk factors.

Previous reports provide evidence that nicotinic acetylcholine receptors (nAChRs) …

Toward Personalized Medicine: The Potential Role Of Rna Interference In Plasma Cell Dyscrasia, Jonathan E Phipps

Doctoral Dissertations

A major contributor to mortality in patients with plasma cell dyscrasias (PCDs); i.e., multiple myeloma, light chain deposition disease and AL amyloidosis is the deposition as insoluble aggregates of monoclonal immunoglobulin light chain proteins (LC) in the kidneys and other organs. Currently anti-plasma cell chemotherapies are used to reduce LC synthesis, and slow deposition. While effective, these treatments are toxic, non-specific, expensive, and might not be appropriate in all cases, making the identification of an alternate means of reducing toxic LC species desirable. To this end, we have investigated whether RNA interference (RNAi) could achieve these goals.

Human (RPMI 8226, …

Immunologic Risk Prediction Model For Kidney Graft Function, Christina Diane Bishop

Doctoral Dissertations

Clinicians lack appropriate non-invasive methods to be able to predict, diagnose, and reduce the risk of rejection in the years following kidney transplantation. Protocol biopsies and monitoring of serum creatinine levels are the most common methods of monitoring graft function after transplant; however, they have several negative aspects. Use of traditional factors regarding donors and recipients such as Human Leukocyte Antigen (HLA) DNA typing, pre-transplant anti-HLA antibody levels, and basic demographics (age, ethnicity/race, gender), has proved inadequate for post-transplant graft monitoring past the first few years. We propose that by utilizing immunologic factors available to clinicians across the United States, …

Role Of Il-17 And Th17 Cells In Hsv Induced Ocular Immunopathology, Amol Sahebrao Suryawanshi

Doctoral Dissertations

Herpes simplex virus (HSV) infection of the cornea leads to a blinding immuno-inflammatory condition of the eye also called stromal keratitis (SK). SK immunopathology is characterized by the infiltration of CD4⁺ T cells of Th1 phenotype as well as the development of new blood vessels into the normally avascular cornea. Studies in mouse models of SK have firmly established the role of CD4⁺ T cells, and particularly of Th1 phenotype, as the principal mediators of SK immunopathology. However, with the recent discovery of IL-17A and Th17 cells, the role of this cytokine as well as Th17 cells remains …

Mechanism Of Phospholipid Induction Of Cell Migration, Dongwei Wu

Doctoral Dissertations

Lysophosphatidic acid (LPA) is a potent bioactive lipid component of oxidized low density lipoproteins (oxLDL). High concentrations of LPA have been detected in human atherosclerotic plaques. Our data has shown that LPA highly induces smooth muscle cell (SMC) migration. Cyr61, a matricellular protein, which also accumulates in human atherosclerotic plaques, has been implicated in the injury-induced neointimal formation. Smooth muscle cell migration is a key event in the development of atherosclerosis, and it contributes to the progressive growth of atherosclerotic lesions. Data generated by this study demonstrate that LPA markedly induces Cyr61 expression in mouse aortic smooth muscle cells (MASMC). …

Development Of An Autonomous Mammalian Lux Reporter System, Daniel Michael Close

Doctoral Dissertations

Since its characterization, the definitive shortcoming of the bacterial luciferase (lux) bioluminescent reporter system has been its inability to express at a functional level in the eukaryotic cellular background. While recent developments have allowed for lux function in the lower eukaryote Saccharomyces cerevisiae, they have not provided for autonomous function in higher eukaryotes capable of serving as human biomedical proxies. Here it is reported for the first time that, through a process of poly-bicistronic expression of human codon-optimized lux genes, it is possible to autonomously produce a bioluminescent signal directly from mammalian cells. The low background of …

Stem Cell Biology And Strategies For Therapeutic Development In Degenerative Diseases And Cancer, Angel A. Alvarez '98

Doctoral Dissertations

Stem cell biology is an exciting field that will lead to significant advancements in science and medicine. We hypothesize that inducing the expression of stem cell genes, using the embryonic stem cell gene nanog, will reprogram cells and dedifferentiate human mesenchymal stem cells into pluripotent stem cells capable of neural differentiation. The aims of initial studies are as follows:

Aim 1: Demonstrate that forced expression of the embryonic stem cell gene nanog induces changes in human mesenchymal stem cells to an embryonic stem cell-like phenotype.

Aim 2: Demonstrate that induced expression of nanog up-regulates the expression of multiple embryonic stem …

The Regulation Of Neuropeptide Corazonin And Its Functional Analyses In Drosophila Melanogaster, Seung-Hoon Choi

Doctoral Dissertations

Neuropeptides regulate diverse physiological processes, including homeostatic metabolism, behavior, reproduction, and development. The neuropeptide Corazonin (Crz), was first isolated from American cockroach, P. americana, as a potent cardioactive substance, and has been shown to exert diverse functions in different insects. In Drosophila, Crz expression is limited to three groups of neurons; totaling only 26 neurons out of ~10,000 neurons in a third instar larval central nervous system (CNS). In adults, Crz is expressed in 6-8 pairs of protocerebral neurons and 2 pairs of male specific abdominal ganglion. To gain insight into such tight regulatory mechanisms of …

The Effects Of 17- Beta Estradiol On G-Protein Inwardly Rectifying Potassium Channels (Girks) In Breast Cancer, Michael W. Hance

Doctoral Dissertations

Breast cancer is a leading cause of cancer death and in 2009, the American Cancer Society estimates that over 192,000 new cases of breast cancer will be diagnosed, and over 40,000 women will die from breast cancer. Estrogen (E2) is required for normal female development and reproduction, but long-term exposure is carcinogenic and considered a risk factor for breast cancer. Membrane ion channels are essential for cell proliferation and are suggested to have a role in cancer, especially potassium channels. In the present study, we investigate the effects of estrogen and the estrogen antagonist ICI182780 on G-protein inwardly rectifying potassium …