Medicine and Health Sciences Commons^™

Enhance Representation Learning Of Clinical Narrative With Neural Networks For Clinical Predictive Modeling, Yuqi Si

Dissertations and Theses (Open Access)

Medicine is undergoing a technological revolution. Understanding human health from clinical data has major challenges from technical and practical perspectives, thus prompting methods that understand large, complex, and noisy data. These methods are particularly necessary for natural language data from clinical narratives/notes, which contain some of the richest information on a patient. Meanwhile, deep neural networks have achieved superior performance in a wide variety of natural language processing (NLP) tasks because of their capacity to encode meaningful but abstract representations and learn the entire task end-to-end. In this thesis, I investigate representation learning of clinical narratives with deep neural networks …

Secondary Use Of Structured Electronic Health Records Data: From Observational Studies To Deep Learning-Based Predictive Modeling, Laila Bekhet

Dissertations and Theses (Open Access)

With the wide adoption of electronic health records (EHRs), researchers, as well as large healthcare organizations, governmental institutions, insurance, and pharmaceutical companies have been interested in leveraging this rich clinical data source to extract clinical evidence and develop predictive algorithms. Large vendors have been able to compile structured EHR data from sites all over the United States, de-identify these data, and make them available to data science researchers in a more usable format. For this dissertation, we leveraged one of the earliest and largest secondary EHR data sources and conducted three studies of increasing scope. In the first study, which …

Assessing Sleep Efficiency Of Nulliparous Women In The Third Trimester Of Pregnancy, Ran Hu

Dissertations and Theses (Open Access)

Objectives: Pregnant women in the third trimester are more likely to experience sleep disorders, resulting in adverse effects on fetal health. This study aimed to evaluate the sleep efficiency (SE) of nulliparous women in their late pregnancy.

Methods: Data was extracted from the National Sleep Research Resource focusing on nulliparous women (n = 1,803) in their third trimester of pregnancy. The two-sample Wilcoxon test for continuous variables and the Chi-square test for categorical variables were used based on a normal SE cut-off of 0.85. The least absolute shrinkage and selection operator (Lasso) was used to find the risk …

Standardizing New Diagnostic Tests To Facilitate Rapid Responses To The Covid-19 Pandemic, Xiao Dong

Dissertations and Theses (Open Access)

In order to enhance the data interoperability, an expeditious and accurate standardization solution is highly desirable for naming rapidly emerging novel lab tests, and thus diminishes confusion in early responses to pandemic outbreaks. This is a preliminary study to explore the roles and implementation of medical informatics technology, especially natural language processing and ontology methods, in standardizing information about emerging lab tests during a pandemic, thereby facilitating rapid responses to the pandemic. The ultimate goal of this study is to develop an informatics framework for rapid standardization of lab testing names during a pandemic to better prepare for future public …

Epithelial Memory Of Resolved Inflammation Limits Tissue Damage While Promoting Pancreatic Tumorigenesis, I-Lin Ho

Dissertations and Theses (Open Access)

Inflammation is a major risk factor for pancreatic ductal adenocarcinoma. When occurring in the context of pancreatitis, mutations of KRAS accelerate tumor development. We discovered that long after its complete resolution, a transient inflammatory event primes pancreatic epithelial cells to subsequent transformation by oncogenic KRAS. Upon recovery from acute inflammation, epithelial cells of the pancreas display an enduring adaptive response associated with sustained transcriptional and epigenetic reprogramming. Such adaptation enables the prompt reactivation of acinar-to-ductal metaplasia (ADM) upon subsequent inflammatory events, thus efficiently limiting tissue damage via rapid decrease of zymogen production. We propose that since activating mutations of KRAS …

Manipulating Enhancer Rna Activity To Study Their Roles In Gene Regulation And Cancer, Zian Liao

Dissertations and Theses (Open Access)

Enhancers are essential regulatory elements that precisely control gene transcription during development and disease. Especially in cancer, enhancers modulate tumor gene expression, and in some cases directly drive tumorigenesis. With the recent advances in next-generation sequencing, researchers discovered that active enhancers are pervasively transcribed into RNAs, which are named enhancer RNAs (eRNAs). Studies have suggested that eRNAs have a functional role in the enhancer action mechanism. Studying their roles will provide a new understanding of gene regulation and cancer development. In my MS study, I focused on using novel methods to study eRNA functions. Using a breast-cancer-specific eRNA, I have …

Effect Of Lactoferrin To Increase Drug Permeability Of Primary Pulmonary Mycobacterial Granulomas, Thao Nguyen, Thao Kt Nguyen

Dissertations and Theses (Open Access)

Despite extensive research and worldwide eradication efforts, Mycobacterium tuberculosis (Mtb) remains a major infectious pathogen to the human population with about 10 million cases of infection per year globally. The host-pathogen interaction, pulmonary granuloma formation, and Mtb adaptions result in increased complexity of the disease. Granulomas are formed by active immune responses generated during Mtb infection, and serve to contain and limit bacterial dissemination. The major mycobacterial surface mycolic acid, trehalose 6,6'-dimycolate (TDM), functions in multiple ways to enhance immune cell recruitment of sites of infection, to induce inflammation and granulomatous responses, and to initiate survival strategies for …

Vascular Disease Pathogenesis In Smooth Muscle Dysfunction Syndrome And Majewski Osteodysplastic Primordial Dwarfism Type Ii, Jamie Wright

Dissertations and Theses (Open Access)

Vascular diseases are a leading cause of morbidity and mortality world-wide. Understanding their pathogenesis is crucial to better diagnosis and management of these life-threatening conditions. Through the study of rare mutations that lead to early onset and severe vascular diseases, we can elucidate underlying mechanisms for vascular disease pathogenesis and develop better treatments to prevent and manage more common causes of vascular diseases. In this study we look at two rare diseases that lead to severe vascular phenotypes, Smooth Muscle Dysfunction Syndrome (SMDS) and Majewski Osteodysplastic Primordial Dwarfism Type II (MOPDII). SMDS is a rare condition due to pathogenic variants …

Targeting Plasma Membrane Phosphatidylserine Content To Inhibit Oncogenic Kras Function, Walaa E. Kattan

Dissertations and Theses (Open Access)

The small GTPase KRAS, which is frequently mutated in human cancers, must be localized to the plasma membrane (PM) for biological activity. We recently showed that the KRAS C-terminal membrane anchor exhibits exquisite lipid-binding specificity for select species of phosphatidylserine (PtdSer). We therefore investigated whether reducing PM PtdSer content is sufficient to abrogate KRAS oncogenesis. Oxysterol-related binding proteins ORP5 and ORP8 exchange PtdSer synthesized in the ER for phosphatidylinositol-4-phosphate (PI4P) synthesized in the PM. We show that depletion of ORP5 or ORP8 reduced PM PtdSer levels, resulting in extensive mislocalization of KRAS from the PM. Concordantly, ORP5 or ORP8 depletion …

Synthetic Essentiality Of Tdo2 In Apc-Mutated Colorectal Cancer, Rumi Lee

Dissertations and Theses (Open Access)

Inactivation of the adenomatous polyposis coli (APC) tumor suppressor is

common genetic event across many cancers and serves a critical initiating

event in the majority of sporadic colorectal cancers (CRC). The WNT/APC

pathway remains an elusive target for cancer, prompting us to explore

orthogonal strategies to identify specific vulnerabilities for APC-deficient

CRC and other cancers. Using the concept of synthetic essentiality (SE), we

sought to identify essential effectors of APC deficiency with the goal of

expanding targetable vulnerabilities in CRC. We identified Tryptophan 2,3-

dioxygenase 2 (TDO2) as an SE gene for APC-deficient cancers.

Mechanistically, APC loss results in TCF4/b-catenin-mediated …

Conserved Non-Pocket Interactions Drive The Diversity Of Peptide Presentation By Mhc Class I Molecules, Kyle Jackson

Dissertations and Theses (Open Access)

Cytotoxic T-lymphocytes (CTL) can lyse infected or transformed cells through recognition of peptides presented on human leukocyte antigen (HLA) molecules. A thorough understanding of peptide-HLA interactions is needed for improvement of CTL-based immunotherapies. We observed that aspartic acid (D) and glutamic acid (E) at peptide position 4 are highly prevalent in HLA-I peptide ligands, and discovered that they interact with arginine (R) in position 65 and lysine (L) in position 66 of the α1 helix of the binding groove in HLA-A*0201 and HLA-A*2402. Since this interaction differed from well-characterized peptide-HLA anchor interactions mediated by peptide position 2 and the C-terminus, …

Combination Of Oncolytic Adenoviruses, T-Cell Activation, And Blockade Of Ido Metabolic Circuitry For The Treatment Of Glioma, Teresa Nguyen

Dissertations and Theses (Open Access)

Glioblastoma is the most common malignant primary brain tumor in adults; the current aggressive treatment results in a 5% five-year survival rate. More effective therapies should be developed. One promising alternative is oncolytic adenovirus, Delta-24-RGD, which elicits cancer cell lysis and immunogenic cell death. In fact, Delta-24-RGD produced complete responses in 20% of recurrent glioblastoma patients through immune mechanisms that activate anti-tumor cytotoxic properties of T-cells. This cytolytic effect can further be enhanced by adding immune agonists, namely OX40L, which engages the OX40 receptor to co-stimulate activated T cells for enhanced proliferation. Hence, we produced the next generation of Delta-24-RGD, …

Identification And Characterization Of De Novo Germline Tp53 Mutation Carriers In Families With Li-Fraumeni Syndrome, Carlos C. Vera Recio

Dissertations and Theses (Open Access)

Li-Fraumeni syndrome (LFS) is an inherited cancer syndrome caused by a deleterious mutation in TP53. An estimated 48% of LFS patients present due to a de novo mutation (DNM) in TP53. The knowledge of DNM status, DNM or familial mutation (FM), of an LFS patient requires genetic testing of both parents which is often inaccessible, making de novo LFS patients difficult to study. Famdenovo.TP53 is a Mendelian Risk prediction model used to predict DNM status of TP53 mutation carriers based on the cancer-family history and several input genetic parameters, including disease-gene penetrance. The good predictive performance of Famdenovo.TP53 was demonstrated …

Unveiling Global Roles Of G-Quadruplexes And G4-22 In Human Genetics, Ruth Barros De Paula

Dissertations and Theses (Open Access)

G-quadruplexes are non-B DNA structures formed by four or more runs of repeated guanines that confer unique features to living organism’s genomes. These sequences are enriched in regulatory regions, such as promoters and 5’ UTRs, and have distinct regulatory roles in both health and disease states. Even though previous studies showed the impact of G4 in gene expression, none of them summarized the location-specific effect of G4. Also, there is no broad understanding about the most common G4 repeat in the human genome, named here as G4-22, and how it links to the evolution of mammals and their biology. In …

Automation Of Radiation Treatment Planning For Cervical Cancer, Dong Joo Rhee

Dissertations and Theses (Open Access)

Cervical cancer is one of the most common cancer in low- and middle-income countries (LMICs). The mortality rate can be reduced if radiation treatment becomes widely available. However, due to the lack of radiation treatment facilities and human resources, many cervical cancer patients in Africa are not able to receive timely treatments or advanced therapies. To increase the availability of radiation treatment in low-and middle-income countries (LMICs) including African countries, many attempts have been made to reduce the cost of medical linear accelerators. However, increasing the number of treatment machines would not instantly resolve the issues, as there would be …

Quantitative Magnetic Resonance Imaging For The Early Prediction Of Treatment Response In Triple Negative Breast Cancer, Benjamin C. Musall

Dissertations and Theses (Open Access)

Triple Negative Breast Cancer (TNBC) is an aggressive subtype of breast cancer which lacks upregulated hormone receptors. Because of this, it is not vulnerable to clinically available targeted therapies. When treated with standard of care neoadjuvant systemic therapy (NAST), TNBC only shows approximately a 40% rate of pathologic complete response (pCR). A biomarker which could predict TNBC response to NAST early during treatment would be useful, as it would allow for non-responders to be triaged to alternative therapies and potentially allow for the treatment of responders to be de-escalated.

Quantitative Magnetic Resonance Imaging (MRI) may be used to probe and …

Development Of Quantitative Molecular Photoacoustic Imaging For Noninvasive Cancer Diagnostics, Cayla Zandbergen

Dissertations and Theses (Open Access)

Traditional diagnostic imaging provides clinicians with anatomical information that guides both diagnosis and treatment planning; however, once a tumor has progressed enough to be visible, it has often reached an advanced stage. Molecular imaging techniques allow for real-time visualization of chemical and biological processes via imaging of specific biomarkers, which can facilitate detection of malignancies before they become visible. One biomarker of interest is blood oxygen saturation (SO₂) due to its correlation with hypoxia, which is associated with increased tumor malignancy; some studies have also established SO₂ as an independent biomarker of disease progression. Additionally, because cancerous …

Understanding The Pathogenesis Of Renal Medullary Carcinoma, Melinda Soeung

Dissertations and Theses (Open Access)

Renal medullary carcinoma (RMC) is a lethal cancer that predominantly affects young individuals with sickle cell trait (SCT). It is not currently understood why RMC only affects certain individuals with SCT. We found that patients with RMC more frequently participated in high-intensity exercise than matched controls. Using mouse models of SCT, we demonstrated the significant increase of renal hypoxia in the right kidney following high- but not moderate-intensity exercise. We also demonstrated in cell culture studies that SMARCB1 is ubiquitinated for proteasome-mediated degradation in hypoxia, and the re-expression of SMARCB1 leads to compromised proliferation in renal cells specifically in the …

Dissecting The Mechanisms Of Venetoclax Resistance In Myelodysplastic Syndromes, Shuaitong Chen

Dissertations and Theses (Open Access)

Myelodysplastic syndromes (MDS) are a class of heterogeneous clonal hematopoietic disorders. The current standard of care for MDS is the hypomethylating agent (HMA)-based therapy. However, only 50 percent of the patients respond, with transient effects and no approved second-line treatment options after their diseases progress to acute myeloid leukemia (AML). The mechanisms that govern HMA failure are unknown. Recently, we unveiled that MDS are maintained and propagated by two different immunophenotypically distinct hierarchical cellular organizations of MDS hematopoietic stem and progenitor cells (HSPCs) through the upregulation of specific survival pathways. This finding allowed us to potentially stratify MDS patients into …

Virulence And Biofilm Formation In Candida Albicans Are Inhibited By Short Peptide Subunits Of Entv, Shane Cristy

Dissertations and Theses (Open Access)

Candida albicans, the most clinically significant fungal pathogen, commonly causes topical mucosal infections such as oral cavity and urogenital tract infections. It also less frequently causes severe invasive and bloodstream infections. Invasive infections are most prevalent amongst patients with compromised innate immune responses, such as those receiving chemotherapy or recovering from surgery. C. albicans can also form biofilms on implanted medical devices. Fungal infections are difficult to treat due to the paucity of therapeutic options, and this problem is compounded by the resistance properties of biofilm infections.

Candida albicans exists as a member of the commensal flora of the …

The Importance Of Dna Repair Capacity To (And A Model To Predict) Cell Radiosensitivity To Ions, David B. Flint, David B. Flint

Dissertations and Theses (Open Access)

Radiation therapy with ions has a number of advantages over conventional radiation therapy with photons, including favorable depth-dose distributions, greater relative biological effectiveness (RBE) and a lesser dependence on a number of biological factors known to affect radiosensitivity to photons, including DNA repair capacity. Thus, it is expected that an additional benefit of using ions is that they mitigate the great heterogeneities in treatment responses commonly observed in photon therapies.

However, by analyzing the cell survival of human cancer cell lines exposed to clinically relevant photon, proton, and carbon ion beams, we show there is not significantly less relative variability …

The Microsatellite Instability High Endometrial Tumor Microenvironment And Identifying Predictive Biomarkers Of Response To Pembrolizumab, Jeffrey How

Dissertations and Theses (Open Access)

Objective: Half of patients with microsatellite instability high (MSI-H) endometrial cancer are treatment-refractory to pembrolizumab. We sought to evaluate the MSI-H endometrial tumor samples to examine differences in the tumor microenvironment (TME) and identify transcriptomic signatures associated with response/resistance to pembrolizumab. Methods: Archival tumor samples from MSI-H endometrial cancer patients treated at MD Anderson Cancer Center were obtained. Tissue samples originating from patients who did not receive pembrolizumab treatment (“untreated cohort ”; n = 11) were analyzed via RNA sequencing (RNA-seq). Pre-treatment archival tumor samples (“treated cohort”; n = 23) from patients who were later treated with pembrolizumab were collected …

Dissecting Tumor Heterogeneity In Lung Cancer, Aparna Padhye

Dissertations and Theses (Open Access)

Lung cancer is a heterogeneous disease composed of genetically and phenotypically distinct tumor cells as well as a heterogeneous microenvironment consisting of non-cancer cells and extracellular matrix. Constant interactions among these components ultimately leads to a complex tumor tissue that is ever evolving and poses a therapeutic challenge for sustained benefit. Strategies for targeting lung cancers are largely guided by the genetic alterations identified in the tumor specimens. However, in order to gain a better understanding of lung cancer progression and develop effective treatment modalities, studying tumor in context of its microenvironment is crucial. The first aim of this project …

Understanding The Role Of Arglu1 In Interferon Signaling Activation In Breast Cancer, Phuoc Nguyen

Dissertations and Theses (Open Access)

In the U.S., the highest number of new cancer cases belongs to breast cancer in women, and this cancer also bears the second-highest death rate in women. Despite significant progress in breast cancer treatment that has been made in the past several decades, innovative and efficient therapies are still needed to eradicate this deadly disease. Novel cancer immunotherapy with immune checkpoint blockade (ICB) could induce long-lasting responses and improve survival in hard-to-treat malignancies. Regrettably, only a fraction of breast cancer patients respond to this highly promising strategy. To improving ICB therapy in breast cancer treatment, IFN signaling induction is a …

Intranasal Hpv Peptide Vaccine Formulation Induces Potent Cytotoxic Cd8 T Cell Immunity For The Treatment Of Genital Hpv Tumors, Gloria Sierra

Dissertations and Theses (Open Access)

Human Papillomavirus (HPV) induced cancers continue to affect millions of women worldwide, with the five year survival rate hovering just under 60% in some demographics. Therefore there is an unmet need to develop effective, yet, easily administered therapies to treat established HPV genital lesions. Even though immune checkpoint therapy (ICT) is a promising treatment option in some HPV+ cancers, the high cost and associated toxicities are still major concerns for their widespread application. HPV cancers are textbook candidates for therapeutic vaccination intervention because they’re driven by the expression of viral oncoproteins E6 and E7, which serve as ideal tumor specific …

Identification And Targeting Of Downstream Ar-Camkk2-Mediated Mechanisms For The Treatment Of Advanced Prostate Cancer, Chenchu Lin

Dissertations and Theses (Open Access)

The androgen receptor (AR) is the primary driver of prostate cancer and, therefore, AR-regulated signaling events are essential for the development and progression of the disease. Despite their initial effectiveness, drugs targeting AR eventually fail as sustained inhibition of receptor activity remains a challenge. Previously, Ca²⁺/calmodulin-dependent protein kinase kinase 2 (CAMKK2) was identified as an essential downstream component of AR signaling in prostate cancer that correspondingly tracked with disease progression. While the importance of CAMKK2 in AR-mediated prostate cancer progression has been established, our understanding of the events downstream that promote the disease remains incomplete. Here, I elucidated …

Trim24 Promotes Mammary Tumor Development By Upregulating Metabolic Reducing Power, Shucheng Miao

Dissertations and Theses (Open Access)

Metabolic reprograming is an emerging hallmark of cancer cells. Changes in cellular metabolism can contribute to cancer cell survival and tumor progression. Tripartite motif-containing protein 24 (TRIM24) is an E3 ligase for p53, a nuclear receptor co-regulator, and a histone reader. Over expression of TRIM24 correlates with poor overall survival of breast cancer patients. Previously, our lab created a mouse model that conditionally over-expresses (COE) TRIM24 protein in mammary epithelia (Trim24^COE) and develops carcinosarcoma or metaplastic mammary tumors (70% of all Trim24^COE tumors), a rare and aggressive triple-negative subtype called metaplastic TNBC in humans (MpBC). RNA-sequencing …

Micrornas As A Therapeutic Target To Regulate Microglial Activation In Post­ Stroke Isolation In Aged Male Mice, Anik Banerjee

Dissertations and Theses (Open Access)

Introduction:

It is increasingly recognized that social Isolation (SI) leads to a wide array of behavioral and cognitive deficits. Isolation and loneliness are linked to all-cause mortality, as well as mortality from stroke and other vascular diseases. In addition, isolated or lonely individuals have significantly poorer cognitive and functional outcomes following stroke and have higher rates of stroke recurrence. These detrimental effects have also been recapitulated in animal models; animals isolated prior to, or at the time of stroke, have larger infarcts than pair-housed mice. However, the mechanisms mediating the effects of social factors on stroke recovery are unknown. An …

Investigating The Role Of Abro1 In Dna Damage-Induced Immune Response, Ahmed Emam

Dissertations and Theses (Open Access)

Genomic instability can be induced by various forms of genotoxic stress and it is a hallmark of human cancer that is associated with metastasis, therapeutic resistance, and poor prognosis. During replication stress, the replication fork stalls and forms a reversed fork which may be degraded by several DNA nucleases. At the stalled fork, genome stability is maintained by fork end protection and subsequent restart of the replication. Abro1 has been shown to play an important role in protecting the integrity of the stalled replication forks by inhibiting DNA2 nuclease. Deficiency of Abro1 leads to stalled replication fork degradation and genomic …

Advancement Of A 3d Computational Phantom And Its Age Scaling Methodologies For Retrospective Dose Reconstruction Studies, Aashish Gupta

Dissertations and Theses (Open Access)

We have used a 3D age-scalable computational phantom for over two decades for retrospective dose reconstruction studies of childhood cancer survivors (CCS) treated with 2D historic radiotherapy (RT). However, our phantom and its age scaling functions (ASF) must be updated so that it can be used in studies that include survivors treated with contemporary RT. We aimed to implement our phantom and its age scaling functions in DICOM format and determine the feasibility of applying our ASFs to accurately scale the whole-body CT-based anatomies.

In the implementation study, we developed Python scripts that model the phantom and ASFs in a …