Medical Sciences Commons^™

Ai-Driven Segmentation And Volumetric Response Modeling Of Liver Regions To Radiotherapy, Aashish Chandra Gupta

Dissertations and Theses (Open Access)

In liver-directed radiotherapy (RT), liver regions receiving higher doses typically undergo atrophy while contralateral/adjacent lower-dose regions may exhibit compensatory hypertrophy through regeneration of healthy tissue. Optimizing the RT plan to promote regional hypertrophy while minimizing the risk of developing atrophy has the potential to enhance post-RT liver function and long-term survivorship. However, current clinical practice largely relies on global liver dose-volume metrics during RT-planning, which may obscure favorable dose-response correlation and limit actionable guidance for clinicians. Therefore, we hypothesized that post-RT regional liver response is governed by a combination of region-specific dose-volume and patient clinical features, and that these responses …

Host-Intrinsic Factors Determine Anti-Tumor Efficacy Of Exercise In Pancreatic Ductal Adenocarcinoma, Sumedha Pareek

Dissertations and Theses (Open Access)

Pancreatic Ductal Adenocarcinoma (PDAC) is the third leading cause of cancer-related deaths with a low 5-year relative survival rate of approximately 13.3% for all stages combined. We have previously shown that exercise can improve quality of life and enhance functional capacity among patients with PDAC. Exercise induces a variety of changes in the tumor microenvironment with beneficial effects in several tumor types. However, our understanding of the clinical effects of exercise and the mechanisms that mediate anti-tumor effects are limited in pancreatic cancer.

In this project, using C57BL/6 mice from Taconic Biosciences (Tac) and Jackson Laboratories (Jax), we established a …

Capsinoids, Non-Pungent Trpv1 Agonists, Induce A Mild Hypothermia That Provides Short- And Long-Term Neuroprotection After Ischemic Stroke, Alexander Andersohn, Alexander Andersohn

Dissertations and Theses (Open Access)

Therapeutic hypothermia (TH) has demonstrated neuroprotection in instances of cardiac arrest and neonatal hypoxia/ischemia but faces different challenges in application to stroke due to the activation of cold defense mechanisms in conscious patients. This dissertation examines the efficacy and specificity of capsinoids (a purified mixture of capsiate and dihydrocapsiate) to induce a sustained mild hypothermia in conscious mice that is neuroprotective after stroke. Capsinoids function as TRPV1 agonists. However, unlike capsaicin, capsinoids are vulnerable to esterase-mediated breakdown, thus significantly restricting their action to the site of delivery. We showed that capsinoids delivered intraperitoneally (IP) to mice induced a TRPV1-dependent drop …

Effects Of Sex And Aging In The Response To Global Cerebral Hypoperfusion, Alexis Mcalister

Dissertations and Theses (Open Access)

Introduction

The prevalence of dementia worldwide is projected to double by the year 2030 and triple by 2050. Vascular cognitive impairment and dementia (VCID) encompasses diseases that lead to cognitive decline and dementia due to cerebrovascular disease. VCID is the second most common form of dementia after Alzheimer’s disease, accounting for approximately 15- 40% of all dementia cases. Reductions in cerebral blood flow from intracranial and extracranial atherosclerosis increase VCID risk, even in the absence of overt clinical or imaging evidence of stroke/embolization. The pathology seen in patients with chronic cerebral hypoperfusion, such as inflammation, neuronal loss, white matter abnormalities, …

Artificial Intelligence (Ai)-Assisted Cardiotoxicity Management In Lung Cancer Radiotherapy, Xinru Chen

Dissertations and Theses (Open Access)

Lung cancer remains one of the leading causes of cancer-related mortality worldwide, with radiation therapy being a cornerstone of treatment. However, radiation-induced cardiotoxicity has emerged as a significant long-term complication, impacting patient survival and quality of life. There is increasing evidence that post-radiotherapy cardiotoxicity is better indicated by cardiac substructure dose, compared with whole heart dose. Despite this, cardiac substructures are not routinely incorporated into clinical workflows due to the significant time and resource demands associated with manual segmentation. Moreover, the relationship between dose distribution in radiotherapy plans and radiation-induced cardiotoxicity remains incompletely understood. Therefore, the development of an automated …

Fc Gamma Receptors Facilitate Antigenic Modulation Of Lilrb4 And Function As Predictive Biomarkers In Acute Monocytic Leukemia, Joshua Morse

Dissertations and Theses (Open Access)

Acute monocytic leukemia (monocytic AML) is a subtype of AML marked by a proliferation of abnormal monoblasts. This subtype represents approximately 10% of AML cases. The prognosis of monocytic AML is poor, with a 5-year survival of ~30%. Most patients are diagnosed at an age when they are unlikely to survive first-line non-targeted cytotoxic chemotherapy as a bridge to hematopoietic stem cell transplant (HSCT). Even patients who achieve remission commonly relapse. This population of patients would greatly benefit from precision-targeted therapies but currently there are none approved for monocytic AML.

Leukocyte immunoglobulin-like receptor B4 (LILRB4) is an immune checkpoint expressed …

Ascl2 Positive Tumor Cells Modulate The Response Of Metastatic Colorectal Cancer To Mapk-Targeting Therapy, Oscar Eduardo Villarreal

Dissertations and Theses (Open Access)

Colorectal cancer (CRC) is the second leading cause of cancer related deaths with nearly a quarter of patients presenting with metastatic disease at the time of their diagnosis. Therapeutic management of metastatic CRC continues to be a major challenge due to therapy resistance and disease heterogeneity. Due to its central role in tumorigenesis, CRC is commonly treated with MAPK pathway inhibitors (MAPKi). However, clinical trials repeatedly demonstrates that durability of benefit is short-lived in many patients. While genomic mechanisms of acquired resistance have been described, they explain a minority of patients, and further research is needed to determine the underlying …

Immune Landscape Of Early Liver Metastatic Lesions In A Novel Immunocompetent Murine Colorectal Cancer Metastasis Model, Alaa Mohamed

Dissertations and Theses (Open Access)

Colorectal cancer minimal residual disease (MRD) represents a major clinical problem for colorectal cancer patients, with failure rates of surgery and adjuvant chemotherapy between 5% to 40% depending on stage of disease. In our study, we simulated MRD using genetically engineered organoids with precise somatic editing of APC and TP53, creating a murine model that mimics human liver metastatic colorectal cancer. By implementing a meticulously timed experimental metastatic model, we could detect microscopic tumor lesions. Through genomic and transcriptomic analyses, we pinpointed the importance of macrophages, particularly those expressing high levels of CSF1R, in these microscopic metastatic focal lesions. We …

Relationship Between Processing Body Formation, Epithelial-To-Mesenchymal Transition, And Invasion In Lung Adenocarcinoma, Amanda Warner

Dissertations and Theses (Open Access)

Lung cancer is the leading cause of cancer-related deaths in the United States, largely due to its ability to metastasize. Epithelial-to-mesenchymal transition (EMT) is a process that enhances the ability of cells to lose their cell-cell contacts, invade, and enter the blood stream which are essential during metastasis. Many transcriptional gene programs are altered during EMT such as activation of mesenchymal transcription factors, like ZEB1, and enhanced response to the TGFβ1 cytokine. In oncogenic contexts, TGFβ1 enhances the formation of processing-bodies (P-bodies) where P-body proteins are required for invasion in multiple cancerous cell lines. P-bodies are a type of ribonucleoprotein …

Development Of Lineal Energy Spectrum-Based Biological Effects Models For Protons, Joseph M. Decunha, Fada Guan, David Grosshans, Zhongxing Liao, Dragan Mirkovic, Oleg Vassiliev, Radhe Mohan

Dissertations and Theses (Open Access)

In this dissertation, methods are developed and described to allow for the rapid calculation of microdosimetric spectra (specifically, lineal energy) for protons. SuperTrack, a GPU-accelerated tool for calculation of microdosimetric spectra was developed and is capable of computing lineal energy spectra up to 5000x faster than using Geant4 directly. Proton lineal energy spectra generated by SuperTrack are indistinguishable from those generated by Geant4. With SuperTrack, large libraries of lineal energy spectra for monoenergetic protons spanning 0-300 MeV have been developed. The proton lineal energy spectra calculated by SuperTrack have been compared to experimental measurements made by a tissue equivalent proportional …

Elucidating The Multi-Omics Of Early-Onset Colorectal Cancer, Jumanah Alshenaifi

Dissertations and Theses (Open Access)

The incidence and mortality rates of sporadic early-onset colorectal cancer have increased in recent decades, but there is no clear etiological basis for this trend. EOCRC is commonly defined as colon and rectal cancers diagnosed before the age of 50 years. The rising incidence of EOCRC has made it the second most common cancer and the third leading cause of cancer death in this age group. The rising incidence of EOCRC is also documented internationally in more than 20 countries across different continents. Clinically, EOCRC has a distinct, more aggressive clinical profile than LOCRC. While approximately 15% of EOCRC cases …

Combined Inhibition Of Lysine-Specific Demethylase 1 And Kinase Signaling As A Preclinical Treatment Strategy In Glioblastoma, Lea Stitzlein

Dissertations and Theses (Open Access)

Glioblastoma is the most common primary malignant brain tumor in adults, with limited treatment options resulting in a poor prognosis. Lysine-specific demethylase 1 (LSD1) is overexpressed in glioblastoma and contributes to tumor growth and treatment resistance. Inhibitors of LSD1 have shown preclinical promise but have had limited clinical development for glioblastoma. Given the frequent kinase pathway alterations in glioblastoma, the interplay between LSD1 inhibition and kinase signaling pathways was investigated to identify vulnerabilities that could be exploited through rationally designed combination therapies. We hypothesized that LSD1 inhibitors would activate kinase signaling pathways, such as MAPK, and the addition of kinase …

Investigating Prefrontal Cortex Neuronal Signatures Of Opioid-Induced Risk-Taking Behavior, Cana Quave

Dissertations and Theses (Open Access)

Opioid use disorder occurs alongside impaired risk-related decision-making, but the underlying neural correlates are unclear. We developed an approach-avoidance conflict task using a modified conditioned place preference procedure to study neural signals of risky opioid seeking in the prefrontal cortex, a region implicated in executive decision-making. Following morphine conditioned place preference, rats underwent a conflict test in which fear-inducing cat odor was introduced in the previously drug-paired side of the apparatus. While the saline-exposed control group avoided cat odor, the morphine group included two subsets of rats that either maintained a preference for the paired side despite the presence of …

Automated To Ols For Contour Review In Radiotherapy, Barbara Marquez

Dissertations and Theses (Open Access)

Peer review of organ-at-risk and target volume delineation is essential for patient safety and optimization of treatment outcomes. Peer review makes a substantial impact on patient outcomes, reporting notable rates of plan changes when reviewed and worse survival when patient cases are not reviewed. In around half of revised cases, target volume change is the required cause for modification (related to tumor control); in one in ten cases, it is normal tissue sparing (related to treatment toxicity). Essentially all North American institutions with accredited residency training programs hold peer review to some capacity. However, accessibility to practicing routine peer review …

An Investigation Into The Potential Of Cell Therapies For Acute Myeloid Leukemia (Aml) Treatment, Amanda Eckstrom

Dissertations and Theses (Open Access)

Despite recent advances in acute myeloid leukemia (AML) treatment, curative rates remain poor with high rates of relapse and many patients are unable to tolerate the intensive chemotherapy standard of care regimen. Cell therapies have shown great success against hematologic malignancies but face several challenges including treatment-related toxicities and human-leukocyte antigen (HLA) matching. Natural killer (NK) cells and gamma delta (γδ) T cells offer alternative effector cell options for cell therapies that do not require HLA-matching and have shown low toxicity in previous studies. In this project, we sought to evaluate FT538 induced pluripotent stem cell-derived NK (iPSC-NK) and donor-derived …

Denial Of Inpatient Genetic Testing: A Study On Outpatient Yield And Outcomes, Cindy Y. Canales

Dissertations and Theses (Open Access)

This study investigates the difference in diagnostic yield between patients approved for inpatient genetic testing compared to those denied inpatient testing and the effect of an earlier diagnosis on outcomes and medical/clinical care. In the literature, research has explored the impact of a diagnostic delay for patients with genetics conditions, assessed the utility of genetic testing in the inpatient setting, and described the impact to care of an earlier diagnosis. However, gaps remain on research exploring the diagnostic yields of inpatient versus outpatient settings and the potential impact to care an inpatient genetic testing request denial may pose. This is …

Influential Factors And Predicting Dose Delivery Accuracy For Imaging And Radiation Oncology Core’S Phantom Program Using Machine Learning, Hunter Mehrens

Dissertations and Theses (Open Access)

IROC’s mission is to help ensure consistent and comparable, high-quality radiotherapy across clinics that participate in national clinical trials. To obtain this mission, IROC’s phantom program provides a third-party end-to-end check of the clinical workflow of a patient receiving radiotherapy. The goal of the phantom audit is to compare the dose delivered to the dose planned by the treatment system ensuring dose delivery accuracy. While IROC’s phantoms are better equipped to catch dose delivery errors compared to a clinic’s QA process, the end-to-end process and reporting of results is time-consuming creating a bottleneck for clinical trial participation. Furthermore, IROC’s passing …

The Role Of An Ultraconserved Long Non-Coding Rna In B-Cell Lymphomagenesis, Swati Mohapatra

Dissertations and Theses (Open Access)

Ultraconserved regions (UCRs) are genomic segments with perfect (100%) conservation between the orthologous regions of human, rat, and mouse genomes. UCRs can be transcribed into mono-exonic long non-coding RNAs (lncRNAs) known as transcribed ultraconserved regions (T-UCRs). These regions, despite lacking protein-coding potential, are increasingly recognized for their regulatory roles in gene expression, including the modulation of non-coding RNA (ncRNA) transcripts. NcRNAs play crucial roles in cellular processes, including oncogenic transformation, with emerging evidence revealing their ability to encode small peptides known as ncRNA-encoded peptides (ncPEPs). These peptides, originating from small open reading frames (smORFs), contribute to diverse cellular functions and …

Evaluation Of Myogenic Differentiation Potential Of Bmd Ipscs In Vitro And The Effect Of Ubiquitination Inhibitors On Dystrophin Stability In Vivo, Muchen Liu

Dissertations and Theses (Open Access)

Background: Muscular dystrophies are heterogeneous groups of inherited diseases leading to progressive muscular weakness and degeneration. In the case of Becker muscular dystrophy (BMD), non-disrupting mutations of the DMD gene reading frame is the causative defect. By the age of 30s, about 60 to 70% of BMD patients develop cardiomyopathy, which is often lethal. Unfortunately, there is currently no cure for BMD. Meanwhile, improvement of dystrophin stability by repressing polyubiquitination is a promising strategy. The application of human iPSCs in tissue regeneration also serves as a potential therapeutic strategy. This study aims to test the efficacy of selected drugs interfering …

In Vivo Examination Of Peripheral Drivers Of Alzheimer’S Disease, Celso Catumbela

Dissertations and Theses (Open Access)

Alzheimer’s disease (AD) is the leading cause of dementia worldwide, and predominantly affects elderly populations. This disease is well known for its effects on the brain, but a wealth of clinical reports show that dementia can also modify, or be modified by, various peripheral and systemic processes. Yet, the pathological contribution of peripheral comorbidities to AD remains to be fully understood. In an attempt to address some knowledge gaps, we characterized the cerebral and peripheral pathology in mice with history of either liver injury or sepsis. In the former subjects, we found that even in the absence of genetic risk …

Sleep Disturbances In Adults With Tsc: Influences Of Treatment And Clinical Features, Kirstin Risgaard

Dissertations and Theses (Open Access)

Tuberous sclerosis complex (TSC) is a rare genetic condition caused by pathogenic variants in the TSC1 or TSC2 genes. TSC is characterized by a multisystem, neurocutaneous phenotype including skin lesions, hamartomas, and epilepsy. Additionally, TSC can present with an array of behavioral, psychiatric, academic, psychosocial, intellectual, or neuropsychological difficulties comprehensively known as TAND, or TSC-associated neuropsychiatric disorders. Sleep disorders are a common feature of TAND; however, they are not well characterized in the adult TSC population. Likewise, little is known about how clinical features of the condition and commonly prescribed medications impact sleep. Therefore, this study aimed to determine the …

Mutational Landscape Of Noncoding Ultraconserved Elements In Human Cancers: Functional Relevance And Clinical Utility, Recep Bayraktar

Dissertations and Theses (Open Access)

The mutational landscape of phylogenetically ultraconserved elements (UCEs), especially those in noncoding DNA regions (ncUCEs), and their functional and clinical relevance in cancers remain poorly characterized. In this thesis, we perform a systematic analysis of whole-genome sequencing (WGS) data from the International Cancer Genome Consortium (ICGC) and in-house targeted sequencing of 13,736 UCEs and demonstrate that ncUCE somatic alterations are pervasive. Using a genome-wide multiplexed CRISPR knockout screen in colorectal cancer (CRC) cell lines, we show that the loss of several mutated ncUCEs impacts cancer cell proliferation. In-depth functional studies in vitro and in vivo further reveal that UCE_11311 is …

Molecular Mechanisms Of Opioid Use Disorder In Human Brain Models, Emily Mendez

Dissertations and Theses (Open Access)

Opioid use disorder (OUD) is a national and global public health crisis with no end in sight. While studies from animal models hint at widespread epigenetic and transcriptomic alterations of opioid drugs, the molecular consequences of long-term exposure to opioid drugs in human brain is still unclear, and human-centered translational models are necessary to discern the human cell type-specific effects of OUD.

Using postmortem brain Brodmann area 9 (BA9) from the UTHealth Brain Collection for Research on Psychiatric Disorders, I identified angiogenic gene networks perturbed in the RNA and protein of OUD subjects, as well as downregulation of many neuron-correlated …

Investigating The Role Of The Gut Microbiota On Immune Checkpoint Inhibitor-Mediated Colitis, Taylor Halsey, Robert Jenq

Dissertations and Theses (Open Access)

Immune checkpoint inhibitors (ICIs) have been revolutionary in the fight against cancer by recruiting the host immune system as an agent for attack on malignant cells. Unfortunately, immune-related adverse events (irAEs), including ICI-mediated colitis (IMC), are common side effects that result from immune cell mediated damage on healthy tissues. Recent studies have highlighted a role for the gut microbiota in modulating ICI-mediated anti-tumor responses, but less is known regarding how the gut microbiota may impact on irAEs. Considering that the gastrointestinal tract harbors thousands of unique microbial species, many of which are known to modulate the immune system, microbes and …

Evaluation Of An End-To-End Radiotherapy Treatment Planning Pipeline For Prostate Cancer, Mohammad Daniel El Basha, Court Laurence, Carlos Eduardo Cardenas, Julianne Pollard-Larkin, Steven Frank, David T. Fuentes, Falk Poenisch, Zhiqian H. Yu

Dissertations and Theses (Open Access)

Radiation treatment planning is a crucial and time-intensive process in radiation therapy. This planning involves carefully designing a treatment regimen tailored to a patient’s specific condition, including the type, location, and size of the tumor with reference to surrounding healthy tissues. For prostate cancer, this tumor may be either local, locally advanced with extracapsular involvement, or extend into the pelvic lymph node chain. Automating essential parts of this process would allow for the rapid development of effective treatment plans and better plan optimization to enhance tumor control for better outcomes.

The first objective of this work, to automate the treatment …

Cord Blood-Derived Invariant Natural Killer T Cells As A Platform For Allogeneic Chimeric Antigen Receptor Cell Therapy, Maison Grefe

Dissertations and Theses (Open Access)

Chimeric antigen receptor (CAR) T cells have revolutionized the treatment of hematopoietic malignancies achieving >50% complete response rates in numerous refractory/relapsed B cell malignancies. However, there are challenges that hinder CAR-T efficacy and bar the broader use of this therapy in patients. One approach to address these challenges is to create a safe allogeneic CAR cell product by using cells that do not cause graft versus host disease (GvHD). Invariant natural killer T (iNKT) cells are an ideal candidate as they are restricted to the monomorphic CD1d protein in contrast to HLA restricted αβ-T cells and therefore are safe in …

Inclusion Of Adoption As A Pregnancy Management Option In Prenatal Genetic Counseling Practice, Emma Billings

Dissertations and Theses (Open Access)

Prenatal genetic counselors are essential to providing education, psychosocial support, and guidance on pregnancy options to patients who receive a fetal diagnosis of an anomaly or genetic condition. Therefore, genetic counselors should be well-educated on comprehensive pregnancy management options consisting of parenting, abortion, and adoption. The landscape of adoption education in genetic counseling practice was last characterized in 2010 by Perry and Henry, revealing substantial variability in both the inclusion of adoption-specific education in genetic counseling program (GCP) curricula and the discussion of pregnancy options with patients in prenatal practice. As a result, the authors published a call to action …

Methods For The Prediction Of Osteoradionecrosis Resulting From Head And Neck Cancer Radiation Therapy, Brandon Reber

Dissertations and Theses (Open Access)

Head and neck cancer (HNC) is the sixth most diagnosed cancer worldwide with over 600,000 patients diagnosed every year. One of the primary methods to treat HNC is through radiation therapy (RT). While RT is effective at treating HNC, late toxicities resulting from treatment can occur months to years post-treatment and can cause debilitating quality of life changes for HNC survivors. One of these late toxicities is osteoradionecrosis (ORN), which is the death of bone due to radiation. For HNC, the mandible is commonly affected and can cause challenges chewing, swallowing, and physical appearance changes. Several factors indicate the pressing …

Retinoid X Receptor As A Mediator Of Post Stroke Recovery By Reversing Age-Associated Phenotypes Of Microglia/Macrophages, Shun-Ming Ting

Dissertations and Theses (Open Access)

After stroke, microglia (MG) and blood-derived macrophages, together (MF), clear dead cells and cellular debris in the infarcted brain through phagocytosis. However, the phagocytic capability of MF declines with age. Age-related changes in MF phenotype also include overactive inflammatory responses to stroke-induced brain injury, altogether resulting in poor recovery after stroke. Retinoid-X-receptor (RXR) is a pleiotropic transcription factor. Our studies suggest that RXRa enhances MF phagocytic functions, reduces inflammatory responses, and improves post-stroke recovery. To establish phenotypes of aging MF, MG were MACS-sorted from the brains of young adults (2-4 months old) and aged (18-20 months old) mice for transcriptomic …

Epiregulin As A Novel Target For Antibody-Drug Conjugate Development For The Treatment Of Colorectal Cancer, Joan Jacob

Dissertations and Theses (Open Access)

Antibody-drug conjugates (ADCs) are a fast-growing class of molecularly targeted therapies with 13 currently approved and over a 100 in clinical trials. ADCs consist of a monoclonal antibody (mAb) conjugated to a potent cytotoxic payload to selectively target tumor antigens highly expressed on the cell surface. ADC development has been limited in colorectal cancer (CRC) by the lack of novel and effective therapeutic targets. Epiregulin (EREG), is an epidermal growth factor receptor (EGFR) ligand that is highly expressed in CRCs of different subtypes and mutational statuses with low expression in normal tissues. Here, we have characterized the role of EREG …