Medicine and Health Sciences Commons^™

Vaxinsight: An Artificial Intelligence System To Access Large-Scale Public Perceptions Of Vaccination From Social Media, Jingcheng Du

Dissertations & Theses (Open Access)

Vaccination is considered one of the greatest public health achievements of the 20th century. A high vaccination rate is required to reduce the prevalence and incidence of vaccine-preventable diseases. However, in the last two decades, there has been a significant and increasing number of people who refuse or delay getting vaccinated and who prohibit their children from receiving vaccinations. Importantly, under-vaccination is associated with infectious disease outbreaks. A good understanding of public perceptions regarding vaccinations is important if we are to develop effective vaccination promotion strategies. Traditional methods of research, such as surveys, suffer limitations that impede our understanding of …

The Effect Of Traumatic Brain Injury On Tau Pathology By A Potential Seeding Mechanism, George Edwards Iii

Dissertations & Theses (Open Access)

The misfolding, aggregation and accumulation of specific proteins is the overarching concept in protein misfolding disorders (PMDs). The microtubule associated protein tau is known to form insoluble filaments known as neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau (pTau) found in a subset of PMDs called tauopathies, such as Alzheimer’s disease (AD) and chronic traumatic encephalopathy (CTE), among others. Misfolded tau engenders a structurally alternative intermediate conformation that is prone to aggregate having amyloidogenic properties. Formation of amyloids, such as tau aggregates, is proposed to follow a nucleation-polymerization model where misfolded, soluble oligomeric seeds can trigger native proteins to misfold and …

The Role Of Membrane Domains In Protein And Lipid Sorting During Endocytic Traffic, Blanca B. Diaz-Rohrer

Dissertations & Theses (Open Access)

The lipid and protein composition of the plasma membrane (PM) must be tightly controlled to maintain cellular functionality, despite constant, rapid endocytosis. Because de novo synthesis of proteins and lipids is energetically costly, the cell depends on active recycling to return endocytosed membrane components back to the PM. For most proteins, the mechanisms and pathways of their PM retention remain unknown. The work presented here shows that association with ordered membrane microdomains is fully sufficient for PM recycling and that abrogation of raft partitioning leads to their degradation in lysosomes. These findings support a model wherein ordered membrane domains mediate …

Uncovering The Zeb1 Interactome To Identify Novel Regulators Of Metastatic Non-Small Cell Lung Cancer, Roxsan Manshouri

Dissertations & Theses (Open Access)

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death in the United States, due in part to the robust affinity of lung cancer cells to metastasize. Understanding the processes that contribute to metastasis provides promise for the discovery of novel therapeutic targets. Epithelial-tomesenchymal transition (EMT) is a proposed model for the initiation of metastasis. During EMT cell adhesion and polarity is reduced, allowing epithelial cancer cells to dissociate from the primary tumor and invade distant organs. The transcription factor zinc finger E-box-binding homeobox 1 (ZEB1) has been reported to uniquely correlate with NSCLC disease progression and to …

The Role Of Gamma Oscillations And Cortical Inhibition In The Development Of Working Memory In Adolescence, Christopher P. Walker

Dissertations & Theses (Open Access)

Adolescence is a dynamic period of social, cognitive, and biological changes. In particular, working memory, the ability to actively encode and maintain information over a short period of time, develops early in childhood and gradually increases in capacity and stability during adolescence. The precise neurophysiological mechanism by which working memory capacity increases during adolescence is unclear. The objective of this investigation was to evaluate the role of cortical gamma-band (> 30 Hz) oscillations—which are associated with working memory in adults—for the development of working memory capacity in adolescents, and to identify the extent to which the temporal profile of gamma-aminobutyric …

A Novel Switch-Like Function Of Delta-Catenin In Dendrite Development, Ryan Baumert

Dissertations & Theses (Open Access)

The formation of neuronal networks in the brain is tightly regulated, and dependent on the morphology of dendrites, the branch-like signal-receiving structures extending from neurons. Disruptions in dendrite development, or dendritogenesis, can lead to the atypical neuronal connectivity associated with multiple neurodevelopmental diseases. My research addresses molecular processes that underlie dendritogenesis via analysis of a pair of novel interactions involving the protein delta-catenin.

In neurons, delta-catenin localizes to dendrites and synapses, where it functions in their development and maintenance. Structurally, delta-catenin possesses a central Armadillo domain and a C-terminal PDZ-binding motif. This motif associates with PDZ domain-containing proteins, and is …

Utilizing Temporal Information In The Ehr For Developing A Novel Continuous Prediction Model, Kang Lin Hsieh

Dissertations & Theses (Open Access)

Type 2 diabetes mellitus (T2DM) is a nation-wide prevalent chronic condition, which includes direct and indirect healthcare costs. T2DM, however, is a preventable chronic condition based on previous clinical research. Many prediction models were based on the risk factors identified by clinical trials. One of the major tasks of the T2DM prediction models is to estimate the risks for further testing by HbA1c or fasting plasma glucose to determine whether the patient has or does not have T2DM because nation-wide screening is not cost-effective.

Those models had substantial limitations on data quality, such as missing values. In this dissertation, I …

Design And Architecture Of An Ontology-Driven Dialogue System For Hpv Vaccine Counseling, Amith Faheem Muhammad

Dissertations & Theses (Open Access)

Speech and conversational technologies are increasingly being used by consumers, with the inevitability that one day they will be integrated in health care. Where this technology could be of service is in patient-provider communication, specifically for communicating the risks and benefits of vaccines. Human papillomavirus (HPV) vaccine, in particular, is a vaccine that inoculates individuals from certain HPV viruses responsible for adulthood cancers - cervical, head and neck cancers, etc. My research focuses on the architecture and development of speech-enabled conversational agent that relies on series of consumer-centric health ontologies and the technology that utilizes these ontologies. Ontologies are computable …

Investigations Of The Structure-Function Relationship In Kainate Receptors Using FöRster Resonance Energy Transfer, Douglas Litwin

Dissertations & Theses (Open Access)

Kainate receptors belong to the family of ion channels known as the ionotropic glutamate receptors. Ionotropic glutamate receptors mediate the majority of excitatory synaptic transmission, modulate the release of presynaptic glutamate, and facilitate dendrite formation. Kainate receptors are unique among the ionotropic glutamate receptors in being modulated by sodium ions. They have also been implicated in the development of higher learning and epilepsy. In recent years a wealth of structural data has become available for the AMPA and NMDA classes; however, the structural characterization of kainate receptors has been limited. The work in this dissertation utilizes luminescence resonance energy transfer …

Investigating The Role Of Cd109 In Pancreatic Ductal Adenocarcinoma, Mennatallah Shaheen

Dissertations & Theses (Open Access)

Pancreatic Ductal Adenocarcinoma (PDAC) is the 3rd leading cause of cancer death in the US. We performed loss of function genomic screening on a cohort of four patient derived PDAC cell populations and our data shows a cell surface receptor CD109 to be a common vulnerability, the biologic role of which in PDAC is yet unstudied and largely unknown. We hypothesized that CD109 expression provides PDAC cells with a survival advantage, and promotes cancer progression through activation of downstream signaling. We believe therefore that targeting CD109 could improve PDAC patients’ survival. Here we report that CD109 plays a role in …

Role Of C-Met And Egfr In Acquired Resistance To Parp Inhibitors In Triple-Negative Breast Cancer, Clinton Yam

Dissertations & Theses (Open Access)

Triple-negative breast cancer is associated with a poor prognosis and treatment options are limited. The Poly (ADP-ribose) polymerase (PARP) inhibitors, olaparib and talazoparib, were recently approved for metastatic breast cancer (including triple-negative breast cancer) in patients with a germline BRCA1/2 mutation. Despite impressive response rates of ~60%, the prolongation in median progression-free survival with PARP inhibitors is modest, suggesting the emergence of resistance. We previously demonstrated that c-MET contributes to intrinsic resistance to PARP inhibitors in triple-negative breast cancer. However, whether c-MET plays a role in acquired resistance to PARP inhibitors in triple-negative breast cancer remains unclear. Here, we show …

The Influence Of The Pep-Pts And Other Metabolic Systems On The Master Virulence Regulator Atxa And Toxin Gene Expression In Bacillus Anthracis, Naomi Bier-Reizes

Dissertations & Theses (Open Access)

AtxA, the master virulence gene regulator in Bacillus anthracis, is a PRD-containing virulence regulator (PCVR) as indicated by the crystal structure, post-translational modifications, and activity of the protein. PCVRs are transcriptional regulators, named for the regulatory domains subject to phosphorylation by the phosphoenolpyruvate phosphotransferase system (PEP-PTS), termed PTS Regulatory Domains (PRD), and for their impact on virulence gene expression. Generally, the phosphorylation of a PCVR regulates protein activity and multimerization. AtxA is phosphorylated at two histidine residues - one in each of its two PRDs. Phosphorylation at position 199 allows for AtxA to positively affect expression of virulence genes, whereas …

Bilirubin Nanoparticle As An Anti-Inflammatory Therapy For Graft Versus Host Disease, Sumedha Pareek

Dissertations & Theses (Open Access)

Graft versus host disease (GvHD) caused by alloreactive donor lymphocytes is a fatal complication of hematopoietic stem cell transplant (HSCT). Myeloablative conditioning regimen, consisting of chemotherapy and/or radiation, given prior to HSCT can cause tissue damage. This non-specific tissue damage triggers cross-presentation of alloantigens to the donor immune cells, causing recruitment of leukocytes and production of inflammatory cytokines. Targeting this inflammation without affecting the anti-leukemia effects of HSCT, continues to be one of the biggest challenge in finding a therapy for GvHD. Bilirubin is a tetrapyrrole pigment, found in the blood, with natural anti-oxidative and anti-inflammatory properties. Using mouse models …

Modeling Cancer Using Li-Fraumeni Syndrome Patient-Derived Induced Pluripotent Stem Cells, Ruoji Zhou

Dissertations & Theses (Open Access)

Li-Fraumeni syndrome (LFS) is an autosomal dominant disease caused by germline mutations in the gene TP53, which predispose individuals to a wide range of malignancies, including osteosarcoma and breast cancer. In the previous study, our group developed a novel disease model platform by reprograming LFS patients' fibroblasts to induced pluripotent stem cells (iPSCs), and further differentiate these iPSCs into mesenchymal stem cells (MSCs) then to osteoblasts (OBs), the cells from which osteosarcomas originate. Interestingly, LFS iPSC-derived osteoblasts recapitulated the osteosarcoma phenotype, creating “a bone tumor in a dish”. This “tumor in a dish” platform proved that LFS is an …

Dissecting The Roles Of Human Smc Complexes In Transcription Regulation And Chromatin Organization, Ruoyu Wang

Dissertations & Theses (Open Access)

Metazoans utilize a constellation of distal regulatory elements to control gene transcription, and therefore they have to forge highly complex chromatin loops to spatially bridge these regulatory elements and genes in the three-dimensional (3D) genome. However, the hierarchy of chromatin contacts and their underlying mechanisms are not well-understood. SMC complexes including Cohesin complex and Condensin complex has been widely proposed to organize 3D genome structure, and further regulate metazoans’ gene transcription. Here, we aim to dissect the direct functions of SMC complexes (both Cohesin and Condensin) in transcriptional regulation and 3D genome organization, by utilizing an inducible protein degradation system. …

Fasting Reduces Intestinal Radiotoxicity Enabling Dose-Escalated Radiotherapy For Pancreatic Cancer, Marimar De La Cruz Bonilla

Dissertations & Theses (Open Access)

Surgical resection is the only potentially curative treatment for pancreatic cancer, but only 15-20% of patients have resectable tumors. In unresectable cases, stereotactic body radiotherapy (SBRT) may be used to give tumor-directed radiotherapy (RT). Unfortunately, this can cause severe gastrointestinal (GI) toxicity due to proximity of the pancreatic head to the duodenum. Protecting the intestine from the toxic side-effects of radiation may enable dose-escalation that could achieve more effective local control of disease. We and others have previously shown that a fast of 24 hours protects mice from lethal doses of the DNA-damaging agent etoposide. In this study, we demonstrate …

The Gsk-3Β-Fbxl21 Axis Regulates Tcap Via Ubiquitin-Mediated Proteasomal Pathway In The Cytoplasm, Jiah Yang

Dissertations & Theses (Open Access)

Protein turnover is one of the most essential mechanisms controlling circadian rhythms. F-Box and Leucine Rich Repeat Protein21 (FBXL21) is a circadian E3 ligase which shows oscillatory mRNA transcripts and protein levels. It was previously found to perform subcellular compartment-specific E3 ligase activities targeting the core clock proteins CRYPTOCHROME(CRY)1/2. Here we identified a new sarcomeric target substrate, Telethonin(TCAP), which also shows circadian oscillation in its mRNA transcript and protein expression and, importantly, interaction with FBXL21 in an anti-phasic manner. Via computational and pharmacological tests, we identified Glycogen Synthase Kinase-3β(GSK-3β) as a regulator of FBXL21. Biochemical and molecular characterizations demonstrated that …

Gcn5 Loss Impacts Myc-Driven Cancer In Mice And Human Cells, Aimee Farria

Dissertations & Theses (Open Access)

GCN5 is the catalytic subunit in the acetyltransferase module of SAGA and ATAC, multiprotein complexes involved in the modification of histone and nonhistone proteins. GCN5 is most recognized as a co-activator of gene transcription. The SAGA complex is recruited to chromatin by transcription factors such as MYC and E2F1 where GCN5 acetylates H3K9 leading to a more open and accessible chromatin structure. Previous research has demonstrated that GCN5 also acetylates MYC, a protein that amplifies the expression of cancer-promoting genes and is frequently dysregulated in cancer, increasing its stability. Our lab has found there is a significant overlap in the …

P53r245w Mutation Elicits Metastatic Phenotype In Pten Deficient Prostate Cancer, Ky Pham

Dissertations & Theses (Open Access)

Trp53 mutations are the most frequent genetic alterations in prostate cancer and are associated with more aggressive disease and worse overall survival. The majority of Trp53 mutations in prostate cancer are missense mutations, resulting in amino acid substitutions with profound effect. In addition to the loss of wild type function, missense mutations in Trp53 result in a gain-of-function (GOF) phenotype. This GOF phenotype confers biologic advantages to the tumor cells, enabling them to metastasize and invade distant organs. In this study, we generated mice carrying a conditional prostate-specific p53R245W mutant and Pten deletion to access the role of this common …

Molecular Consequences Of High Taz Expression In Gliomas, Visweswaran Ravikumar

Dissertations & Theses (Open Access)

Diffuse high grade gliomas are complex and lethal neoplasms of the adult central nervous system that are driven by a range of genetic and epigenetic alterations. Molecular classification of these tumors has identified different transcriptional subtypes, the most notable being Proneural (PN) and Mesenchymal (MES) classes. The most aggressive forms of the disease have a Mesenchymal expression signature, with reported PN-to-MES transition occurring with tumor progression. Master regulatory analysis has identified the transcriptional co-activator TAZ (WWTR1) as a major driver of the MES transition. Overexpression of this single protein in glioma stem cells has been shown to drive a transition …

Hypoglycemia In Mitochondrial Disorders, Allison Moats

Dissertations & Theses (Open Access)

INTRODUCTION: The electron transport chain (ETC) in mitochondria functions to produce energy in the form of adenosine triphosphate (ATP). Defects in the mitochondrial or nuclear DNA that codes for components of the ETC lead to mitochondrial disorders (MTDs). MTDs are multi-system conditions affecting the heart, muscles, and especially brain. The endocrine system is commonly affected in MTDs, and diabetes and hyperglycemia are established secondary diagnoses. Rates of non-iatrogenic hypoglycemia have not been studied in individuals with MTDs. This study aims to investigate the frequency of hypoglycemia in patients with MTDs.

METHODS: Individuals diagnosed with a ‘definite’ or ‘probable’ …

Sequence-Specific Gene Correction Of Cystic Fibrosis Airway Basal Cells, Varada Anirudhan

Dissertations & Theses (Open Access)

Cystic fibrosis (CF) is a lethal monogenic disease resulting from mutations in the CFTR gene which encodes a protein involved in regulating anion trans-epithelial transport. A three-base deletion in CFTR (termed as ΔF508 mutation), wherein CFTR protein is misfolded leading to its pre-mature degradation in the endoplasmic reticulum (ER), is the most common cause of this debilitating disease. Since CFTR is expressed in multiple body systems, CF affects different organs, but lung pathology is the greatest cause of death in affected patients. We achieved site-specific gene correction with an efficiency of ~10 % in CF airway basal cells homozygous for …

Cross-Presentation Is A Source Of Tumor Antigens For Multiple Myeloma Immunotherapy, Alexander A. Perakis

Dissertations & Theses (Open Access)

Cross-presentation is an essential bridge between the innate and adaptive arms of the immune system where antigen presenting cells (APCs) prime cytotoxic T cell responses. We have recently identified cross-presentation as a mechanism by which solid tumors present exogenous antigens. We therefore hypothesized that multiple myeloma would be capable of cross-presentation as these cells are derived from B cells, known APCs. We explored the capacity of multiple myeloma to cross-present PR1, a human leukocyte antigen (HLA)-A2 nonameric peptide that is derived from neutrophil elastase (NE) and proteinase 3 (P3), and the ability to treat multiple myeloma using PR1-targeting immunotherapies. Here …

Il-6/Jak1 Drives Pd-L1 Phosphorylation And Glycosylation To Promote Cancer Immune Evasion, Li-Chuan Chan

Dissertations & Theses (Open Access)

Glycosylation of immune receptors and ligands, such as T-cell receptor (TCR), major histocompatibility complex (MHC), and co-inhibitory molecules, regulates immune signaling activation, antigen presentation, and immune surveillance. Recent studies revealed that the glycan structures of co-inhibitory molecules are required for receptor-ligand interaction, a critical feature for activating cancer immune evasion. However, it is unclear how oncogenic signaling initiates glycosylation of co-inhibitory molecules to induce immunosuppression. Here we show interleukin (IL)-6-activated Janus kinase 1 (JAK1) phosphorylates programmed death-ligand 1 (PD-L1)-Tyr112, leading to the recruitment of endoplasmic reticulum (ER)-associated N-glycosyltransferase, STT3A, which catalyzes the glycosylation of PD-L1, contributing to its stability. A …

Multimodality Somatostatin Analog For Fluorescence-Guided Surgery In Cancer, Servando Hernandez Vargas

Dissertations & Theses (Open Access)

Cancer surgery remains the primary curative treatment for most solid cancers and has major therapeutic implications for patients with neuroendocrine tumors (NETs). Anatomical and functional imaging technologies are widely used during the pre- and postoperative stages, but intraoperative disease recognition relies on direct visual inspection and the hands of surgeons. The limited number of clinical tools for real-time intraoperative visual feedback restricts the ability to remove the complete cancer source and is partially responsible for the high rate of disease recurrence in patients. Intraoperative imaging with fluorescent contrast agents has the potential to improve the ability of surgeons to detect …

Hsp70-Mediated Regulation Of Hsf1 Transcriptional Activity In Saccharomyces Cerevisiae, Sara Peffer

Dissertations & Theses (Open Access)

In eukaryotic cells, protein homeostasis and cellular fitness is promoted by the transcription factor heat shock factor 1 (HSF1) during exposure to proteotoxic stress. HSF1 controls the basal and stress-induced expression of molecular chaperones and other protective targets. Dynamic regulation of HSF1 involves the major heat shock proteins Hsp70 and Hsp90. Recent advances in the understanding of this regulatory circuit in Saccharomyces cerevisiae have shown that the Hsp70 Ssa1 acts as a sensor for some proteotoxic stresses and is capable of a direct interaction with Hsf1. This work continues to explore the complex regulatory interaction between Hsf1 and Ssa1. I …

Identifying Interest In And Barriers To Psychiatric Genetic Counseling, Samantha Montgomery

Dissertations & Theses (Open Access)

Mental illness is common in the United States and genetic counseling for psychiatric indications can help individuals understand multifactorial inheritance, recurrence risk estimates, and identify ways to protect their future mental health. Despite interest in and efficacy of the service documented in populations outside of the United States, individuals with personal and/or family histories of psychiatric conditions are very rarely accessing psychiatric genetic counseling services. The purpose of our study was to identify interest in and barriers to psychiatric genetic counseling with the hopes of better characterizing this population and improving access to this beneficial service in the future. An …

Platiscity Of C. Elegans Germline Stem Cells Under Nutritional And Metabolic Stress, Kenneth Trimmer

Dissertations & Theses (Open Access)

Stem cells are integral for tissue maintenance and fertility. Therefore, understanding how stem cells are regulated under stress is imperative. When confronted with acute starvation, stem cells must conserve energy and metabolites to cope with the lack of an external source. Caenorhabditis elegans germline stem cells (GSCs) are an excellent model for studying stem cell properties and regulation as they can divide throughout the life of the organism. While GSCs are an adult stem cell population, their cell cycle structure more closely mimics mouse and human embryonic stem cells with short G1 and long S phases. In this thesis, I …

Genetic Counselor Utilization And Interpretation Of Somatic Tumor Testing In Evaluation For Lynch Syndrome, Danielle Williams

Dissertations & Theses (Open Access)

Lynch syndrome (LS) is a hereditary cancer predisposition syndrome characterized by increased risk for colorectal and uterine cancers. Individuals with pathogenic variants in the mismatch repair (MMR) genes (MLH1, MSH2/EPCAM, MSH6, PMS2) are diagnosed with LS and subsequently recommended to proceed with high risk screening protocols to increase prevention and early detection of LS-related cancers. Various tumor studies can help identify those at high risk for LS, but sometimes create uncertainty with discordant screening and germline results, leading to unexplained mismatch repair deficiency (UMMRD). Somatic testing of the MMR genes has created opportunities for resolving …

Identifying Pathogenic Variants In Hereditary Cancer Syndrome Genes Via Tumor Molecular Profiling, Carol Nowlen

Dissertations & Theses (Open Access)

Tumor molecular profiling is often performed in order to direct cancer treatment options. However, because many of the genes analyzed on tumor molecular profiling overlap with genes known to be associated in the germline with hereditary cancer predisposition syndromes, tumor molecular profiling can unknowingly uncover germline predisposition to cancer development. In this study, we determined the number of patients with pathogenic variants (PVs) identified in BRCA1 and BRCA2 (BRCA1/2) via tumor molecular profiling at The University of Texas MD Anderson Cancer Center, then performed a retrospective chart review to determine the proportion of such patients that received germline …