Digital Commons Network^™

A Biomarker Signature-Guided Clinical Trial Design For Precision Medicine, Yuan Li, Dejian Lai, Ruosha Li, Han Chen, Xuelin Huang, Jing Ning

Faculty, Staff and Student Publications

Targeted cancer therapies aim to effectively treat patients with specific biomarker profiles. Nevertheless, these therapies may not always precisely hit their intended targets, leading to uncertainty about the specific subset of patients who will benefit. To address this uncertainty, the identification of sensitive patient subsets in clinical trials becomes crucial. Our proposed phase IIB/III clinical trial design seeks to pinpoint a biomarker signature with precision, ensuring the accurate identification of patients who will respond to a specific treatment. This approach allows for the selective enrollment of sensitive patients to maximize benefits for trial participants. We incorporate Bayesian methodology to facilitate …

Treatment Of C-Met Antibody-Drug Conjugate Asymptomatic Pneumonitis With A Novel Steroid Regimen In Non-Small Cell Lung Cancer: A Case Report, Daniel A Fox, Christine Tran, Vincent Blot, David S Hong

Faculty, Staff and Student Publications

Antibody-drug conjugates (ADCs) are a potent class of antineoplastic drugs that deliver cytotoxic agents via targeting with monoclonal antibodies; however, ADCs are associated with high rates of lung toxicities, limiting the therapeutic potential in many patients. We report a case of a patient with metastatic non-small cell lung cancer taking the ADC telisotuzumab vedotin (Teliso V) plus osimtertinib who developed ADC-induced pneumonitis despite clinical benefit. This patient was able to tolerate treatment for a prolonged period on a novel steroid regimen, using steroids when pneumonitis was asymptomatic but radiologically evident and as a daily suppressant. This treatment strategy may have …

Ethical Concerns And Implications Of Expanded Carrier Screening, Emily Andres

Undergraduate Honors Capstone Projects

The rapid evolution in the field of genetics is often met with uncertainty and skepticism. With the advancements in genetic technologies, expanded carrier screening (ECS) has emerged as a powerful tool in reproductive medicine. Traditionally, carrier screening was provided less broadly, often relying on ethnic-based approaches. However, further advancements have deemed this practice no longer equitable or widely accepted. While ECS provides prospective parents with insight into their genetic risk and may prevent severe genetic conditions, it also raises serious ethical questions for many. These concerns span medical, political, and societal facets including medicalization, defining severity, abortion, legislation, insurability, the …

Pastoral Unity Community Engagement Of Shiprock Area Ministry Association In Shiprock, New Mexico, Rosalind Ann Russell

Doctoral Dissertations and Projects

This praxis project examines the Shiprock Area Ministry Association (SAMA), a pastoral group which represents different religious denominations of faith in the community. SAMA is located on the Navajo Indian reservation in Shiprock, New Mexico and has struggled to return as a group amid the post COVID-19 pandemic. Since its founding as an organization, the group has gathered for support in unity, prayer, and engaged in activities in Shiprock. The return of SAMA members and new membership is to include pastor spouses, church workers, and ministers within a 15-mile radius. The Hershey and Blanchard (2001) Situational Leadership Self-Assessment will be …

An Examination Of How Professional Relationships And Professional Development Influence The Lived Experiences Of African American Women Serving As Superintendents In Texas, Tiffany L. Linwood

Electronic Theses and Dissertations

This qualitative research study investigated the effects of professional relationships and professional development on the experiences of 11 African American women superintendents in Texas, a historically underrepresented minority in educational leadership. It explored the challenges these women have had in advancing to and excelling in superintendent positions, emphasizing the need for mentoring, networking, and ongoing professional development. Despite the variety of students, educational leadership, especially at the superintendent level, is primarily White and male. This study used qualitative approaches, particularly semistructured interviews, to explore the perspectives of African American women superintendents about how professional relationships and growth impact their careers. …

The Contribution Of De Novo Coding Mutations To Meningomyelocele, Yoo-Jin Jiny Ha, Ashna Nisal, Isaac Tang, Chanjae Lee, Ishani Jhamb, Cassidy Wallace, Robyn Howarth, Sarah Schroeder, Keng Ioi Vong, Naomi Meave, Fiza Jiwani, Chelsea Barrows, Sangmoon Lee, Nan Jiang, Arzoo Patel, Krisha Bagga, Niyati Banka, Liana Friedman, Francisco A Blanco, Seyoung Yu, Soeun Rhee, Hui Su Jeong, Isaac Plutzer, Michael B Major, Béatrice Benoit, Christian Poüs, Caleb Heffner, Zoha Kibar, Gyang Markus Bot, Hope Northrup, Kit Sing Au, Madison Strain, Allison E Ashley-Koch, Richard H Finnell, Joan T Le, Hal S Meltzer, Camila Araujo, Helio R Machado, Roger E Stevenson, Anna Yurrita, Sara Mumtaz, Awais Ahmed, Mulazim Hussain Khara, Osvaldo M Mutchinick, José Ramón Medina-Bereciartu, Friedhelm Hildebrandt, Gia Melikishvili, Ahmed I Marwan, Valeria Capra, Mahmoud M Noureldeen, Aida M S Salem, Mahmoud Y Issa, Maha S Zaki, Libin Xu, Ji Eun Lee, Donghyuk Shin, Anna Alkelai, Alan R Shuldiner, Stephen F Kingsmore, Stephen A Murray, Heon Yung Gee, W Todd Miller, Kimberley F Tolias, John B Wallingford, Spina Bifida Sequencing Consortium, Sangwoo Kim, Joseph G Gleeson

Faculty, Staff and Students Publications

Meningomyelocele (also known as spina bifida) is considered to be a genetically complex disease resulting from a failure of the neural tube to close. Individuals with meningomyelocele display neuromotor disability and frequent hydrocephalus, requiring ventricular shunting. A few genes have been proposed to contribute to disease susceptibility, but beyond that it remains unexplained1. We postulated that de novo mutations under purifying selection contribute to the risk of developing meningomyelocele2. Here we recruited a cohort of 851 meningomyelocele trios who required shunting at birth and 732 control trios, and found that de novo likely gene disruption or …

Pathobiology Of Aortic Aneurysms And Dissections: Synthesis Of Recent Investigations And Evolving Insights, L Maximilian Buja, Bihong Zhao, Deborah Vela, Ana Segura, Navneet Narula

Faculty, Staff and Student Publications

The pathobiology of aortic disease is linked to aortic region: atherosclerosis for abdominal aorta, primary medial degeneration or aortitis for ascending thoracic aorta, and all causes for descending thoracic aorta and thoracoabdominal lesions. The pathogenesis of aortic dissection involves damage of the outer media from impaired perfusion from dysfunctional vasa vasorum, formation of discrete foci of disrupted vascular smooth muscle cell-elastic fiber extension-contractile units, and imbalance of radial sheer stress across the aortic wall, thereby creating an intimal tear and linear dissection. Thoracic aortic aneurysms develop from the chronic progression of medial degeneration coupled with the weakening of the remodeled …

Chd1 Loss Reprograms Srebp2-Driven Cholesterol Synthesis To Fuel Androgen-Responsive Growth And Castration Resistance In Spop-Mutated Prostate Tumors, Feiyu Chen, Haoyan Li, Yin Wang, Ximing Tang, Kevin Lin, Qidong Li, Chenling Meng, Wei Shi, Javier Leo, Xin Liang, Jie Zhang, Vivien Van, Iqbal Mahmud, Bo Wei, Philip L Lorenzi, Maria G Raso, Ana Aparicio, Yue Lu, Daniel E Frigo, Boyi Gan, Di Zhao

Faculty, Staff and Student Publications

Despite undergoing castration, most individuals with prostate cancer (PCa) experience progression to castration-resistant PCa (CRPC), in which the androgen receptor (AR) remains an important driver. Concurrent genetic alterations in SPOP and CHD1 define a unique subtype of PCa, but their interactions in tumor progression and therapy response remain unclear. Here, we provide genetic evidence supporting that CHD1 loss accelerates disease progression and confers resistance to castration in males with SPOP-mutated PCa. By leveraging genetic engineering and multiomics, we uncovered a noncanonical function of CHD1 in lipid metabolism reprogramming via repressing the SREBP2 transcriptome. Loss of CHD1 induces cholesterol production, supplies …

From Epithelium To Therapy: Transitional Cells In Lung Fibrosis, Sarah Y Shin, Jichao Chen, Irit Milman Krentsis, Yair Reisner, Rodeo Abrencillo, Rahat Hussain, Danielle Wu, Harry Karmouty-Quintana

Faculty, Staff and Student Publications

Patients with idiopathic pulmonary fibrosis and lung fibrosis secondary to infections such as influenza A and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have limited treatment options outside of supportive therapy and lung transplantation. Multiple lung stem cell populations have been implicated in the pathogenesis of lung fibrosis, and more progenitor cell populations continue to be discovered and characterized. In this review, we summarize the functions and differentiation pathways of various cells that constitute the lung epithelium. We then focus on two subpopulations of KRT5

Identification Of Mitochondrial Defects And Metabolic Consequences In Lynch Syndrome-Related Endometrial Cancer, Mikayla Bowen

Dissertations and Theses (Open Access)

Lynch syndrome (LS), defined by mutations in DNA mismatch repair genes including MSH2, carries a 60% lifetime risk of developing endometrial cancer (EC). Mismatch repair deficiency (MMRd) causes hypermutability, which is assumed to be the main driver of LS-related EC development. However, incomplete penetrance of EC development in women with LS suggests that other modulators are at play. The broad hypothesis of this dissertation is that MMRd causes consequences beyond hypermutability to impact LS-related EC development. Recent studies utilizing our lab’s Msh2-deficient mouse model for LS-EC revealed mitochondrial dysfunction in EC pathogenesis. This new insight led to the …

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 …

Unraveling Epigenetic Mechanisms That Regulate Breast Cancer Lung Metastatic Relapse By Rewiring The Immune Microenvironment, Jayanta Mondal

Dissertations and Theses (Open Access)

Metastasis accounts for >90% of cancer-related deaths and thwarting metastasis is widely considered to be the “Holy Grail” of cancer treatment. Breast cancer is the most common cause of cancer-related death among women and is characterized by its proclivity to spread to distant secondary organs like the lungs, and the brain. These disseminated tumor cells lie dormant at the secondary site and can undergo metastatic relapse. Epigenetic alterations are a predominant hallmark of cancer, however, its role in facilitating reawakening of dormant cancer cells and the subsequent metastatic relapse remains to be elucidated. To address this gap of knowledge, we …

The Extracellular Domains Of The Ampa, Kainate, And Orphan Delta Receptor Regulate Channel Gating In Distinct Ways, Cuauhtemoc Ulises Gonzalez

Dissertations and Theses (Open Access)

The ionotropic glutamate receptors are ligand-gated cationic channels essential for neuroplasticity and neurological functions such as learning, memory, behavior, cognition, and motor coordination. Mutations in these channels are linked to various disorders including autism, ataxia, and epilepsy, making them compelling pharmacological targets. Within this family, the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainate receptor mediate their function through fast glutamate-gated ionotropic activity, which needs precise structural changes to perform properly. While Cryo-EM structures have provided snap shots of these proteins, questions remain regarding the dynamics across conformations and individual roles of the extracellular amino-terminal and agonist binding domain in dictating function. …

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 …

Automated Radiotherapy Treatment Planning For Breast Cancer: A Robust To Ol For Global Deployment, Hana Baroudi

Dissertations and Theses (Open Access)

Breast cancer incidence continues to rise worldwide, particularly in low- and middle-income countries, where limitations in resources already constrain access to timely care. Radiotherapy is a cornerstone of breast cancer management, proven to significantly lower both recurrence and mortality. However, a growing shortage of radiation staff worldwide threatens the prompt delivery of these treatments.This thesis proposes an automated solution to address the limited accessibility of radiotherapy planning in breast cancer management by developing an end-to-end automated treatment planning model and evaluating its performance and limitations across diverse patient populations.

An automated contouring model was trained using data from 104 whole-breast …

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 …

Novel Statistical Methods For Mediation Analysis With High-Dimensional Omics Mediators, Zhichao Xu

Dissertations and Theses (Open Access)

Mediation analysis is a widely used statistical method for examining how molecular traits, such as gene or protein expression, act as intermediaries linking an exposure to a health outcome. For example, it can help explain how smoking affects disease risk through molecular changes. The rapid progress in high-throughput omics profiling technologies and large-scale epidemiology consortia, such as the Trans-Omics for Precision Medicine (TOPMed) program from the National Heart, Lung and Blood Institute (NHLBI) and UK Biobank, now has resulted in an extensive accumulation of genomic data for biomedical research and analysis. At the same time, it poses significant methodological challenges, …

Uncovering A Fundamental Mechanism Underlying Female Oocyte Quality And Rasopathies Using C. Elegans As A Model System, Han Bit Baek

Dissertations and Theses (Open Access)

Signaling pathways are molecular networks that allow cells to communicate between and within themselves. They are crucial for the coordination of diverse cellular processes and are the molecular mechanism in which cells sense and respond to their environment. RAS (Rat Sarcoma) is a small GTPase that transmits extracellular growth factor signals through a downstream kinase cascade and ERK (Extracellular-signal regulated kinase) is the terminal kinase, and it controls cellular processes such as proliferation, differentiation, and survival by phosphorylating its downstream effectors. This post translational modification regulates the effector by modulating its activity, levels, and/or interaction with other molecules. Given the …

"Magic Computer In The Sky" - Participant Perspectives On Control And The Genetic Counseling Admissions Match, Jessica Clark

Dissertations and Theses (Open Access)

Since the 2018 admissions cycle, genetic counseling graduate programs in North America have utilized the Genetic Counseling Admissions Match (GCAM), a Match algorithm to place applicants. While a study prior to implementation found that most students were uninterested in a Match due to concerns of control, there has been no investigation into matched applicants’ experiences since its inception. A mixed-methods study explored the experiences and perceptions of control of genetic counselors and genetic counseling (GC) students who entered a program following the GCAM. An anonymous survey documenting GCAM experience and a validated measure for locus of control (LOC) was disseminated …

Exploring The Immunologic Consequences Of Atrx Deficiency In Glioma, Benjamin Whitfield

Dissertations and Theses (Open Access)

ATRX is a key chromatin regulator that is frequently mutated across multiple cancer types. One of the most common ATRX-mutated tumor types is the adult-type glioma, IDH-mutant, Astrocytoma. It is known that ATRX mutation leads to increases in DNA damage, replication stress, and global epigenetic regulation at a cell level; however, less is known about the impact of ATRX mutation on immune signaling. Furthermore, little is known about the interaction of ATRX loss with gain-of-function mutations in IDH. In this paper we set out to explore the impact of ATRX loss on immune signaling in gliomas, both in the context …

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 …

Stat3, Nf-Κb, And Estrogen Receptor Beta: The Balance Of Inflammation In K-Ras Mutant Lung Adenocarcinoma, Michael J. Clowers

Dissertations and Theses (Open Access)

K-ras mutant lung adenocarcinoma (KM-LUAD) is a difficult-to-treat cancer subtype in which chronic inflammation pervades the tumor immune microenvironment (TIME). Pro-inflammatory pathways dampen the response to treatments, including immune checkpoint inhibitors, necessitating therapies that target this inflammatory signaling network in the TIME. This network is underpinned by interaction and coordination of two inflammatory pathways: signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa B (NF-κB). The balance of these transcription factors determines the degree of anti- vs. pro-tumor immunity, and a skewing towards STAT3 is known to promote tumor development and a pro-tumor TIME. It is also …

Mhc Class I Tyrosine Phosphorylation Site Y320 Augments Cd8+ T Cell Priming, Effector Function, And Memory Response, Yimo Sun, Gregory A Lizee, Yitao Tang, Priscilla Ortiz, R Eric Davis

Dissertations and Theses (Open Access)

The cytoplasmic domain of MHC class I (MHC-I) molecules contains a single, highly conserved tyrosine residue (Y320). In previous work, we found that mice expressing a Y320F-mutated form of H-2K^b had reduced capacity to generate K^b-restricted cytotoxic T lymphocyte (CTL) responses following viral infection, due (at least in part) to defects in endolysosomal trafficking of H-2K^b and antigen cross-presentation by dendritic cells (DCs). In this study, we investigated whether there are additional, post-presentation dependencies on Y320 for T-cell priming. We engineered both human- and mouse-derived antigen-presenting cells (APCs) to express either wild-type MHC-I or variants 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 …

A Qualitative Descriptive Study Of Course Developer/Instructor: Incorporating Systems-Based Knowledge And A Systemic Approach To Performance-Based Instructional Design In Law Enforcement Training, Dalisay A. B. Rosado

Doctoral Dissertations and Projects

The purpose of this qualitative descriptive study was to explore and understand the incorporation of systems-based knowledge and a systemic approach into performance-based instructional design (PBID) in law enforcement training at a regional police academy located in the Eastern time zone of the United States. The theoretical framework for this study was based on Bronfenbrenner's ecological systems theory (EST), which underscores the notion that the practical value of knowledge is measured by its effectiveness in a real-world application, aligning with the principles of performance-based learning. The central question asked was: How do CDIs' ascribed experiences with incorporating or lacking multiple …

Understanding Employee Performance In Technology-Mediated Environments, William Patrick Malloy

Doctoral Dissertations and Projects

The purpose of this qualitative flexible design single case study was to expand the understanding of the dynamics behind performance management in technology-mediated environments and the effect it has on organizational outcomes. Managers in technology-mediated environments struggle to exercise control due to the inadequacy of existing performance management tools designed for traditional settings, which are not adequate in remote and hybrid work contexts. The study was conducted using a constructivist paradigm and a single-case study research design, employing semi-structured interviews, focus groups, and archival data analysis. Data from all sources were coded using NVivo, applying first- and second-cycle coding processes …

An Investigation Of Mental Well-Being Of Black Men: Perceived Discrimination, Depression, Social Support, And Marital Satisfaction, D'Anthony Teon Harris

Doctoral Dissertations and Projects

Black Americans have long endured significant psychological distress due to racism and discrimination. Yet, limited research has examined how these stressors impact the mental health of Black males in the context of marital relationships. This study investigated the effect of perceived discrimination on depression in married African American men, examining whether marital satisfaction mediated this relationship and whether social support moderated it. Rooted in the historical legacy of systemic racism and modern forms of aversive discrimination, the study aimed to fill a gap in the literature concerning the intersection of race, gender, and mental well-being. Utilizing a diverse and well-educated …

Felt Obligation, Knowledge Sharing And Innovation Performance: The Role Of Team Performance Goal Orientation, Zenan Wen

Dissertations and Theses Collection (Open Access)

In today’s dynamic work environment, individual innovation is vital for organizational success. While knowledge sharing is a recognized driver of innovation, less is known about the internal motivational forces that compel employees to share knowledge. Drawing on the role identity theory, this research examines how felt obligation—a normative motivation, whereby individuals, based on their perceived role identities, believe they should care about organizational goals and contribute to them—encourages knowledge sharing and subsequently enhances innovation performance. Furthermore, I theorize that this relationship is strengthened in teams with higher performance goal orientation (TPGO), where norms and expectations regarding performance excellence amplify the …

The Dynamics Of Power Transfer In Organizations: Examining Downward Deference And Its Workplace Consequences, Hoang Bao My Nguyen

Dissertations and Theses Collection (Open Access)

This dissertation examines managerial power transfer as a core mechanism through which less-hierarchical management unfolds in organizations. While traditional management research has emphasized formal authority and top-down control, emerging organizational forms increasingly call on managers to share power with subordinates. Despite growing interest in constructs like empowerment, delegation, and participative leadership, the phenomenon of power transfer remains conceptually fragmented and undertheorized.

To address this, the dissertation defines power transfer as the intentional redistribution of authority, control, or resources by powerholders to lower-power individuals. Chapter 1 develops a typology of power transfer behaviors, organized along two key dimensions: extent of control …

The Sheriff's Constitution, Farhang Heydari

Vanderbilt Law School Faculty Publications

The county sheriff is unique among our nation's law enforcers, with an ancient pedigree, elected status, and special protections as a state constitu- tional officer. But these factors combine to cause a recurrent problem elected sheriffs often assert for themselves the power to refuse to enforce criminal laws of their choosing. Today's constitutional sheriffs-a group of sheriffs who view themselves as the highest authority in their county, answerable only to their electorate-are the latest manifestation of this ethos, declaring opposition to gun control measures, pandemic restric- tions, environmental protections, and more. Lest one think these nonen- forcement decisions are entirely …