Medicine and Health Sciences Commons^™

The Role Of Central Ace2 And Nrf2 In Sympatho-Excitation: Responses To Central Angiotensin Ii, Anyun Ma

Theses & Dissertations

Sympatho-excitation is a key characteristic in cardiovascular diseases such as chronic heart failure (CHF) and primary Hypertension (HTN). Evidence suggests that increased sympathetic tone is closely related to activation of the Renin-Angiotensin-Aldosterone system (RAAS) in the central nervous system. An underlying mechanism for sympatho-excitation is thought to be oxidative stress resulting from Angiotensin II (AngII) type 1 receptor (AT1R) activation. Over the past several decades, pharmacological targeting of components of the RAAS have been used as standard therapy in CHF and HTN. However, additional therapeutic strategies are necessary to control these diseases. Oxidative stress is regulated, in part, by the …

The Evolving Management Of Aortic Valve Disease: Trends In The Utilization And Cost Of Savr, Tavr, And Medical Therapy, Andrew Goldsweig

Theses & Dissertations

Aortic stenosis (AS) and regurgitation (AR) may be treated with surgical aortic valve replacement (SAVR), transcatheter AVR (TAVR), or medical therapy (MT). Data are lacking regarding usage and cost of SAVR, TAVR, and MT for patients hospitalized with aortic valve disease. From the Nationwide Readmissions Database, we determined utilization and cost trends for SAVR, TAVR, and MT in patients with aortic valve disease admitted 2012-2016 for valve replacement, heart failure, unstable angina, non-ST-elevation myocardial infarction, or syncope. From 2012 through 2016, there was a 48.1% increase in the number of patients hospitalized for aortic valve disease annually. Overall, 19.9%, 6.7%, …

Characterizing The Combination Of Rpa Inhibitors With Parp Inhibitors In High-Grade Serous Ovarian Cancer, Yat Tang

Theses & Dissertations

High-grade serous ovarian cancer (HGSC) is the most common and deadly gynecologic malignancy. HGSC patients with BRCA1/2 mutations have homologous recombination deficiency (HRD), requiring parallel pathways to maintain genome integrity (e.g., PARP1, PARP2). Approximately 50% of ovarian carcinomas are estimated to exhibit HRD. For the remaining 50% and the large percentage of HRD patients with acquired or innate resistance to single-agent PARP inhibitors, there is a need to develop alternative therapeutic strategies.

Replication Protein A (RPA) is a heterotrimeric protein crucial for genome maintenance. Phosphorylation of RPA in DNA damage response (DDR) is a negative regulator of DNA end resection. …

Theranostics For Antiretroviral Biodistribution And Pharmacokinetics, Brendan M. Ottemann

Theses & Dissertations

RATIONALE: Our laboratories birthed the field of human immunodeficiency virus (HIV) theranostics. The new field allows simultaneous detection (diagnostics) and treatment (therapeutic) for the identification, treatment and inevitable elimination of virus in cell and tissue compartments. By employing theranostics, antiretroviral drugs (ARVs) can be tracked in lymph nodes, gut, spleen and liver. Cellular viral reservoirs including CD4+ T cell populations and mononuclear phagocytes (MP; monocytes, macrophages, microglia and dendritic cells) along with subcellular endosomal structures can now be targeted for drug delivery bringing therapeutics to areas where virus replicates. The overarching idea rests in improving precision targeted ARV delivery. …

Defining The Role Of Tyrosine Phosphorylation In The Regulation Of Connexin43 In Cardiac Diseases, Li Zheng

Theses & Dissertations

Connexins are integral membrane proteins that oligomerize to form gap junction channels. Ions and small molecules diffuse intercellularly through these channels, allowing individual cellular events to synchronize into the functional response of an entire organ. Gap junction channels composed of Connexin43 (Cx43) mediate electrical coupling and impulse propagation in the normal working myocardium. In the failing heart, Cx43 remodeling (decreased expression, altered phosphorylation state, loss at intercalated discs, and increased presence at lateral membranes) contributes to rhythm disturbances and contractile dysfunction. While there is considerable information regarding key interactions of Cx43 in the regulation of gap junction channels, unfortunately, the …

Delivery Of Small Molecule And Rna Using Synthetic Polymeric Micelles And Multifunctional Exosomes For The Treatment Of Type 1 Diabetes, Yang Peng

Theses & Dissertations

Type 1 diabetes is one of the most challenging chronic autoimmune diseases. The destruction and dysfunction of insulin-secreting β cells are the results of inflammatory infiltration and the synergistic effect of multiple immune cells. The aim of this dissertation is to develop novel and reliable therapeutic approaches to advance the treatment of T1D: including chemical modification of a broad-spectrum immunosuppressant, co-application of small molecule based immune intervention and siRNA based β cell preservative therapy, and administration of a PI3K-δ/γ dual inhibitor to specifically target immune cells, utilizing synthetic polymeric micelles or natural produced multi-functional exosomes derived from human bone marrow …

Engineering Hyaluronic Acid For Biomedical Applications, Deep S. Bhattacharya

Theses & Dissertations

This work presents research using the naturally available non- sulfated carbohydrate glycosaminoglycan hyaluronic acid (HA) for the synthesis of different chemical derivatives of HA for evaluation of binding kinetics with CD44 and P- selectin proteins for applications in fluorescence image-guided surgery. Chemical derivatives of HA such as deacetylated HA (deHA), sulfated HA (sHA), and deacetylated and sulfated HA (s-deHA) were synthesized by modulating sulfating and deacetylating reagents to alter binding specificities to CD44. Modified HA derivatives and CD44 biophysical interactions were assessed by fluorescence polarization. In silico techniques were also used to determine binding using molecular docking and MM-PBSA approaches. …

Computational Studies And Design Of Pparγ And Glut1 Inhibitors, Suliman Almahmoud

Theses & Dissertations

The peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-dependent transcription factor of the nuclear receptor superfamily that controls the expression of a variety of genes involved in fatty acid metabolism, adipogenesis, and insulin sensitivity. PPARγ is a target for insulin-sensitizing drugs, and it plays a significant function in prostate cancer. PPARγ antagonists have anti-proliferative effects in a broad range of hematopoietic and epithelial cell lines. The ligand binding domain (LBD) of PPARγ is large and has orthosteric and allosteric binding sites. Several PPARγ-ligand co-crystal structures show two bound molecules, one to the orthosteric pocket and a second to the allosteric …

The Role Of Histone Chaperone Fact Complex In Base Excision Repair Pathway And Its Therapeutic Potential In Colon Cancer And Medulloblastoma, Heyu Song

Theses & Dissertations

Base excision repair (BER) pathway is required for the removal of damaged bases caused by alkylation, oxidation and ring-saturation. Human apurinic/apyrimidinic endonuclease 1 (APE1) plays a central role in BER pathway. Although repair of damaged bases by recombinant APE1 has been well investigated in vitro, how APE1 gains access to damaged bases in the context of chromatin is largely unknown. A prominent member of the histone chaperone family, FACT (Facilitates Chromatin Transcription) is thought to reorganize nucleosomes through the destabilization of multiple intra-nucleosome contacts. FACT complex is composed of two polypeptides identified as SPT16 (Suppressor of Ty 16) and SSRP1 …

Synthesis And Characterization Of A Long-Acting Emtricitabine Prodrug Nanoformulation, Ibrahim M. Ibrahim

Theses & Dissertations

The introduction of highly active antiretroviral therapy led to a paradigm shift in the management of HIV/AIDS changing a disease considered “a death sentence” to “a manageable chronic disease”. Nevertheless, challenges exist for successful treatment of HIV, including patient adherence to the complex daily regimens and the inability of current formulations to target viral sanctuaries. Introduction of nanoformulated antiretroviral therapy (ART) is a promising alternative to tackle these challenges. Our laboratory has been focusing on developing long-acting (LA) nanoformulated antiretrovirals and has succeeded in developing LA integrase inhibitors. However, challenges for this approach extend to a range of short-acting hydrophilic …

The Role Of Ros In The Progression And Treatment Of Castration-Resistant Prostate Cancer, Dannah R. Miller

Theses & Dissertations

Prostate cancer is the second leading cause of cancer-related deaths in U.S. men, primarily due to the development of castration-resistant (CR) prostate cancer (PCa), of which there are no effective treatment options. Reactive oxygen species (ROS) plays a critical role in prostate carcinogenesis, including the progression of the CR PCa phenotype. ROS regulates both cell proliferation and apoptosis; a moderate increase in ROS can promote proliferation; however, a substantial rise in ROS levels will result in apoptosis. Oxidase p66Shc is elevated in clinical PCa cells and has been associated with a metastatic phenotype of CR PCa cells, promoting PCa cell …

Development Of A Long-Acting Nanoformulation Of Dolutegravir For Prevention And Treatment Of Hiv-1 Infection, Brady Sillman

Theses & Dissertations

Dolutegravir (DTG) is a potent human immunodeficiency virus type 1 (HIV-1) integrase strand-transfer inhibitor (INSTI) with a high barrier to viral drug resistance. However, opportunities to improve its profile abound. These include extending the drug’s apparent half-life, increasing penetrance to “putative” viral reservoirs, and reducing inherent toxicities. These highlight, in part, the need for long-acting, slow effective release antiretroviral therapy (LASER ART) delivery schemes. A long-acting (LA) DTG was made by synthesizing a hydrophobic and lipophilic prodrug encased with poloxamer (P407) surfactant. This modified DTG (MDTG) reduced systemic metabolism and polarity, increased lipophilicity and membrane permeability, improved encapsulation, and formed …

Screening Of Crude Microalgal Extracts For Antimicrobial Activity, Patrick Matulich

Theses & Dissertations

Microbial biofilm associated infections are a significant threat to patients with medical devices and are partially responsible for the increased resistance seen in nosocomial infections. The biofilm chemical and physical properties restrict access of chemotherapeutic agents. Therefore, there is a need to enhance the antimicrobial effects of current chemotherapeutic agents. Microalgae live in competitive environments that include film-forming, opportunistic pathogens S. maltophilia and C. albicans. Extracts from 5 diverse species of microalgae were screened for antimicrobial enhancing effects against established biofilms with two different extraction solvents, 3:1 hexanes and isopropyl (HIPA) and 2-methyltetrahydrofuran (2-MTHF).

Three species, B. braunii, …

Towards An In Vitro Model Of Testing Osteoblast Cellular Function In Contact With Various Surfaces, Raheleh Miralami

Theses & Dissertations

Past studies have shown that the success of total joint replacements depends on the biocompatibility of orthopaedic materials, which can be improved by modifying the implant surface. However, the exact roles of these modifications and their effective mechanisms are poorly understood. The objective of this study was to develop and evaluate a model system to investigate the impact of nano-structured surfaces, produced by the ion beam-assisted deposition (IBAD) technique, on biomarkers of osteointegration using an in vitro model. The IBAD technique was employed to deposit zirconium oxide (ZrO₂), Titanium oxide (TiO₂), and Titanium (Ti) nano-films on …

Functional And Mechanical Role Of Splice Variant Of Mucin4 (Muc4/X) And Trefoil Factors In Pancreatic Cancer Pathogenesis, Rahat Jahan

Theses & Dissertations

Pancreatic Cancer (PC) is one of the vicious cancers as it ranks third in the race of leading cause of cancer-related death. Lack of early diagnostic marker, poor understanding of molecular mechanism of the disease and failure to conventional chemotherapy makes this disease dreadful.

Mucin 4 (MUC4), a high molecular weight glycoprotein is one of the top differentially expressed molecules in PC while not expressed in normal pancreas. Accumulating evidence from our lab suggested its tumorigenic role in PC by increasing cell proliferation, invasion, chemotherapy resistance, tumor growth, and metastasis. Previously, our lab and other has identified 24 different splice …

Early Oral Feeding After Bowel Resection, Jennifer Strang

Theses & Dissertations

Research Focus: The primary purpose of this project was to determine if there was an association of factors with time to first solid meal in gastrointestinal (GI) surgery patients and the impact solid diet has on length of stay (LOS) in the hospital, GI symptoms, and incidence of post-operative ileus (POI). A secondary purpose was to observe and describe when an oral diet was started and the progression of diet after GI surgery.

Research Methods: This study was a cross-sectional, retrospective chart review of a convenience sample in a multi-centered hospital system conducted in 84 GI resection patients …

An Evaluation Of The Use Of A Clinical Research Data Warehouse And I2b2 Infrastructure To Facilitate Replication Of Research, Bret Gardner

Theses & Dissertations

Replication of clinical research is requisite for forming effective clinical decisions and guidelines. While rerunning a clinical trial may be unethical and prohibitively expensive, the adoption of EHRs and the infrastructure for distributed research networks provide access to clinical data for observational and retrospective studies. Herein I demonstrate a means of using these tools to validate existing results and extend the findings to novel populations. I describe the process of evaluating published risk models as well as local data and infrastructure to assess the replicability of the study. I use an example of a risk model unable to be replicated …

Electrophysiological Biomarkers Of Chemotherapy-Related Cognitive Impairment In Hematological Malignancy Patients, David E. Anderson

Theses & Dissertations

Multiple cancer populations frequently report cognitive impairment following treatment with chemotherapy agents (“chemo-brain”). Impaired neuropsychological performance is commonly reported in cognitive domains of attention and executive function. Understanding neural mechanisms underlying cognitive impairments is essential to developing prevention and rehabilitation strategies. Brain imaging studies frequently show chemotherapy-related impairments within the attentional control network, which is comprised of a constellation of cortical regions that govern reportedly impaired cognitive functions. In the current dissertation research, I developed a novel electrophysiology battery aimed at recording near-instantaneous neural activity within the attentional control network during cognitive task performance. Cancer patients diagnosed with hematological malignancy …

Elucidation Of The Functions Of Neuropilin 2 In Osteoclasts In Promoting Prostate Cancer Bone Metastasis., Navatha S. Polavaram

Theses & Dissertations

Bone metastasis is one of the major clinical concerns that causes skeletal related malignancies and increased mortality. Bone is one of the preferred sites for metastatic prostate cancer. The metastatic prostate cancer cells interact with bone cells (osteoblasts and osteoclasts) resulting in an imbalance in the bone homeostasis leading to increased activation of osteoblasts over osteoclasts. Our preliminary data indicated a non-tyrosine kinase receptor Neuropilin 2 (NRP2) is expressed in osteoclasts induced by metastatic prostate cancer cells and acts as a negative regulator of osteoclast differentiation and function. We hypothesize that prostate cancer -induced NRP2 expression in osteoclasts is necessary …

The Beta-Catenin/Muc1.Ct Interaction In Pancreatic Cancer, Edwin Wiest

Theses & Dissertations

MUC1 is overexpressed in over 90% of pancreatic cancer cases, and its interaction with beta-catenin promotes progression of the disease. Various in vitro and in vivo methods show that beta-catenin and MUC1 interact by way of the cytoplasmic tail of MUC1 (MUC1.CT). This interaction occurs in the membrane of pancreatic cancer cells but is found to a smaller extent in the nucleus as well. Biophysical methods suggest that MUC1 interacts with beta-catenin through a sequence of amino acids in the tail of MUC1 that sit very near the transmembrane domain of MUC1. In pancreatic ductal adenocarcinoma cells, it appears that …

Muc4 Based Immunotherapy For Pancreatic Cancer, Kasturi Banerjee

Theses & Dissertations

Pancreatic Cancer (PC) is a lethal disease claiming approximately 45000 lives in the US in 2018, and it establishes an elaborate immunosuppressive tumor microenvironment that aids in disease pathogenesis. Immunotherapy has emerged as a strategy to target tumor cells by reprogramming patient’s immune system. Challenges present in PC immunotherapy are: i) identifying a tumor-associated antigen that could be targeted, ii) identifying adjuvants that could efficiently deliver antigens, iii) eliciting robust anti-tumor responses and iv) overcoming peripheral tolerance and immunosuppression elicited by the tumor.

Firstly, we detected circulating autoantibodies to MUC4 present in PC patients and observed that IgM autoantibodies to …

Functional Signature Ontology-Based Identification And Validation Of Novel Therapeutic Targets And Natural Products For The Treatment Of Cancer, Beth Neilsen

Theses & Dissertations

Multiple studies have revealed that Ras-driven tumors acquire vulnerabilities by adapting cellular mechanisms that promote uncontrolled proliferation and suppress apoptosis. Kinase Suppressor of Ras 1 (KSR1) modulates ERK activation downstream of oncogenic Ras, and knockdown of KSR1 selectively kills malignant, Ras-driven cancer cells, but does not kill immortalized, non-transformed human colon epithelial cells (HCECs). KSR1^-/- mice are fertile and phenotypically normal, but resistant to Ras-driven tumor formation suggesting KSR1 represents a vulnerability in cancer cells.

To identify additional vulnerabilities in cancer, a screening approach termed Functional Signature Ontology (FUSION) was used to screen 14,355 genes and 1,200 natural product …

The Role Of Yes-Associated Protein 1 In Ovarian Physiology And Pathology, Xiangmin Lv

Theses & Dissertations

Ovarian granulosa cells are the major somatic components of the ovarian follicle. Proper proliferation and differentiation of ovarian granulosa cells are essential for successful follicle development. Accumulating evidence indicates that the Hippo-YAP signaling pathway plays critical roles in both development and tumorigenesis of several organs. The present study aims to investigate the role of Yes-associated protein 1 (YAP) in ovarian granulosa cell proliferation, differentiation, and malignant transformation. At first, we found that nuclear YAP (active) was highly expressed in proliferative granulosa cells, whereas cytoplasmic YAP (inactive) was detected mainly in terminally-differentiated luteal cells. Further studies suggested that endogenous YAP activity …

Novel Therapeutic Approaches For Juvenile Neuronal Ceroid Lipofuscinosis (Cln3), Megan Elizabeth Bosch

Theses & Dissertations

Juvenile Neuronal Ceroid Lipofuscinosis (JNCL) is a lysosomal storage disease caused by autosomal recessive mutations in CLN3. Neuronal loss is thought to occur via glutamate excitotoxicity; however, little is known about neuron-astrocyte glutamate regulation in JNCL. We discovered that Cln3^Δex7/8 astrocytes have significantly lower basal spontaneous Ca²⁺ oscillations and decreased responses to glutamate, indicating a disrupted signaling network. Cln3^Δex7/8 astrocytes also displayed significantly lower basal mitochondrial respiration and ATP production, suggesting impaired metabolic functions. Concurrent with diminished astrocyte metabolism and Ca²⁺ signaling, Cln3^Δex7/8 neurons were hyper-responsive to glutamate stimulation. These studies suggest that CLN3 …

Identifying The Role Of Janus Kinase 1 In Mammary Gland Development And Breast Cancer, Barbara Swenson

Theses & Dissertations

The development of the postnatal mammary gland is tightly controlled by peptide hormones and cytokines. The signaling of these extracellular ligands through their corresponding receptors rely on Janus Kinases (JAKs) that activate downstream Signal Transducers and Activators of Transcription (STATs). The JAK/STAT signaling pathway is crucial for processes such as growth, proliferation, and cell survival of the epithelial tissue, but also for the breakdown and remodeling of the mammary gland via IL-6 class inflammatory cytokines (e.g. LIF and OSM). JAK1 and JAK2, which are expressed in the mammary gland, are thought to have redundant functions. However, our previous studies demonstrated …

Dopamine Levels In The Brain Of Rat Models Of Human Rheumatoid Arthritis, Amelia Stinson

Theses & Dissertations

Research Focus. Rheumatoid arthritis (RA) is a chronic, debilitating, autoimmune disease that causes the destruction of bone tissue and the articular structures of joints. At least 30% of RA patient populations have cognitive impairment. Acidic dopamine (DA) is the principal neuroimmunotransmitter that links the central nervous system and peripheral nervous system together. The aim of the present study was to determine the levels of DA and its two acidic metabolites: 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in arthritic induced rats, and whether their levels vary across four different parts of the brain: amygdala (AMG), front cerebral cortex (CX), hippocampus …

An Investigation Of The Levels Of Pro-Inflammation Cytokines In The Brain Of Autoimmune Lewis Rats, Han Yang

Theses & Dissertations

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease, which can cause cartilage and bone damage, as well as disability. A reported symptom of RA includes tissue inflammation disease and cognitive dysfunction. This study aimed to compare the concentration of selected cytokines in the cerebral cortex, hippocampus, hypothalamus, amygdala, and cerebellum of Lewis rats. Age and sex-matched Lewis rats were separated into two groups: control and adjuvant-induced RA. Twenty-eight days after the adjuvant injection, groups were sacrificed and brains dissected using the stereotaxic atlas of Paximos and Watson as a guide. Pro-inflammatory cytokines IL-1β, IL-6, and IL-23, plus the anti-inflammatory …

Redirection Of The Immune Response To Staphylococcus Aureus Biofilm Infection, Anna G. Staudacher

Theses & Dissertations

Staphylococcus aureus (S. aureus) is a leading cause of community- and healthcare-associated infections and has a propensity to form biofilms. Biofilm infections are recalcitrant to host immune-mediated clearance as well as antibiotics, making them exceptionally difficult to eradicate. The biofilm environment has been shown to skew the host immune response towards an anti-inflammatory phenotype, characterized by alternatively activated macrophages, recruitment of myeloid-derived suppressor cells (MDSCs), and minimal neutrophil and T cell infiltrates. Our laboratory has attempted to redirect the host immune response towards one that would favor bacterial clearance by employing strategies to augment pro-inflammatory mechanisms. One such …

Development Of C5ar-Targeted Nanoparticles For Delivery Of Vaccines, Shailendra Bharadwaj Tallapaka Venkata Sesha

Theses & Dissertations

Since the early attempts of Benjamin Jesty at inducing immunity against smallpox and the pioneering work of Edward Jenner, vaccination has been, and continues to remain, the principal method of protection from diseases. However, most of the successful vaccines have been against pathogens that do not have major mechanisms to evade the immune system. So far, many life-threatening diseases like hepatitis C, HIV infection, malaria etc., have been resistant to existing vaccination strategies. Thus, there is an urgent need to develop new vaccination strategies that can generate long-lived protective immunity against such pathogens.

The purpose of this thesis is to …

Added Sugar Consumption Among College Students, Maram Murad

Theses & Dissertations

Added sugar consumption has been increasing in all age groups in the United States and worldwide, with the greatest increase in young adults. College-age years are a critical period in the young adult's life where many habits develop, including nutrition and food choices. An understanding of college-age students’ attitudes and behaviors toward added sugar consumption might help predict added sugar consumption within this population. This was a quantitative study of traditional-aged college students' added sugar consumption through a convenience sample at a private university in San Antonio, TX. A survey was administrated to undergraduate students at different classes. Subjects were …