Master of Sciences (Engineering), Case Western Reserve University, 2020, Biomedical Engineering

The project goal is to dissect the mechanical feedback of cells onto the extracellular matrix (ECM) using De Novo ECM synthesis and traction force microscopy (TFM). In this thesis, we devised a method to apply traction force microscopy to De Novo ECM. We first stimulated 3T3s to synthesize ECM (>=20μm in 10days) using ascorbic acid with experimental conditions of hyperglycemia. After cell removal by lysis, the ECM was measured with AFM and fresh cells were replated for TFM. To achieve TFM on de novo ECM, we developed a serial labeling approach to deposit carboxylated fluorescent beads during multi-day ECM synthesis. We observe that ECM stiffness is increased in high vs low glucose. We also observe a unimodal response of cell traction to increasing stiffness in polyacrylamide substitutes. With the generated TFM bead displacement data, we plan to analyze 3t3s replated onto bead-labeled de novo ECM to better understand the mechanical response of cells.

Committee: Samuel Senyo PhD (Committee Chair); Zheng-Rong Lu PhD (Committee Member); Ozan Akkus PhD (Committee Member) Subjects: Biomedical Engineering

PhD, University of Cincinnati, 2018, Medicine: Pathobiology and Molecular Medicine

Recent technological advances in biomedical, genomics, and computational fields have brought exponential growth in both the amount and accessibility of biological data. These include health records, medical imaging data, omics data including genomics, proteomics, metabolomics, phenomics, disease, and small molecule data. The resultant biological big data poses both great opportunities and challenges. For example, the large amount of heterogeneous data not only allows researchers to query and pursue investigations in health and disease from an unprecedented wide perspective but also enables novel discoveries that were previously obscured by the lack of comprehensive and in-depth analysis. In this dissertation, I use various data-driven approaches to generate testable hypotheses and actionable biological insights related to lung development, disease, and candidate therapeutic discovery. In the first part of this thesis, I used unsupervised machine learning to identify novel cell type and sub types in developing mouse lung from embryonic day (E) 16 to post-natal day (PND) 28 and discovered functionally distinct gene modules associated with each cell populations. These gene modules are analyzed further to identify their roles in lung development, specifically, how they contribute to cell-cell communication during lung development. In the second part of the thesis, I focus on a lethal rare lung disease, idiopathic pulmonary fibrosis (IPF), and identify molecular signatures that not only explain the heterogeneous nature of IPF but also the potential molecular basis of disease severity. I analyzed a large cohort of IPF data and identified clinically significant subgroups using only transcriptomic data. Lastly, I combined connectivity mapping and systems biology-based approaches to identify and prioritize candidate therapeutics for another rare lung disorder – cystic fibrosis (CF). We identified PP-2, a src-kinase inhibitor as a novel CFTR modulator that could potentially (open full item for complete abstract)

Committee: Bruce Aronow Ph.D. (Committee Chair); Anil Jegga (Committee Member); Harinder Singh (Committee Member); Jeffrey Whitsett M.D. (Committee Member); Kathryn WiWikenheiser-Brokamp M.D., Ph.D. (Committee Member) Subjects: Bioinformatics

Master of Sciences, Case Western Reserve University, 2014, Genetic Counseling

Previous studies have identified a positive correlation between weight and pulmonary function of patients with cystic fibrosis (CF). As decreased weight in patients with CF has been observed at birth, this study aimed to identify the predictive quality of birth weight on later complications of CF. Results showed that males with CF (n=40) were on average 10.25 oz lighter at birth (p<0.01) and females with CF (n=39) were on average 9.04 oz lighter at birth (p=0.01) than national averages, matched for gender. Birth weight was correlated with FEV1% at age 6 (p=0.04) but not at ages 10, 15 and 20. Birth weight was not predictive of percent ideal body weight, the age of Pseudomonas colonization, or the incidence of cystic fibrosis related diabetes. These findings suggest that birth weight is predictive of early FEV1%; however, in older patients, other variables contribute to the majority of CF related complications.

Committee: Rebecca Darrah PhD (Committee Chair); Craig Hodges PhD (Committee Member); Anne Matthews PhD (Committee Member) Subjects: Genetics

PhD, University of Cincinnati, 2024, Medicine: Systems Biology and Physiology

Background and significance: Cystic fibrosis (CF) is a genetic disease caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CF pulmonary disease is often characterized by alveolar mucus plugging, fibrosis, chronic inflammation, progressive destruction of the structural airways, and poor ventilation. In fact, the main cause of mortality in CF remains respiratory failure, and as such, CF studies have historically focused on pulmonary outcomes. Studies report pulmonary vascular perturbations and perfusion deficits in CF patients as young as one year old. Mucus plugging and bronchial wall abnormalities only marginally explain the observed perfusion deficit. Although CFTR is expressed and functional in endothelial cells (ECs), the mechanism of pulmonary vascular disease in CF remains unknown. When endothelial cells do not function properly, reduced gas exchange between the alveoli and the pulmonary capillaries can occur, which may cause hypoxemia in CF patients. Therefore, it becomes crucial to uncover the role of CFTR in the endothelium. Objectives: The dissertation aims to investigate how CFTR dysfunction affects endothelial cell response to shear stress and to elucidate the mechanism underlying the progression of CF lung vascular disease. Methods: As part of an ongoing clinical trial, we performed pulmonary vascular morphometry and reconstructed the pulmonary vasculature of 40 individuals with CF. Furthermore, we used a vessel-on-a-chip model to examine the effects of shear stress on CFTR-defective ECs. We also investigated how CFTR dysfunction modulates the activity of the calcium-permeable mechanosensitive channels TRPV4 and PIEZO1. Results: Pulmonary vascular morphometry revealed a loss of small pulmonary blood vessels in CF patients with severe lung disease. Microfluidics studies established a shear stress-dependent mechanism of endothelial barrier failure in CF involving TRPV4 and its downstream calcium (open full item for complete abstract)

Committee: Roger Worrell Ph.D. (Committee Chair); Kyu Shik Mun Ph.D. (Committee Member); Anjaparavanda Naren Ph.D. (Committee Member); Bryan Mackenzie Ph.D. (Committee Member); Kathryn Wikenheiser-Brokamp M.D. (Committee Member); Anil Jegga DVM MRe (Committee Member) Subjects: Cellular Biology

Doctor of Philosophy, Case Western Reserve University, 2024, Genetics

Background: Cystic Fibrosis (CF) is a progressive, systemic disease caused by mutations in the CFTR gene. Despite the availability of highly effective CFTR modulators, there is continued need for the development of CF therapeutics because there is a portion of people with CF not eligible for modulator therapy due to their mutations. CF mouse models are powerful tools to study mutation-specific CF biology and to screen novel therapeutics. This dissertation describes the creation of several novel mouse models using different genetic approaches. Methods & Results: Human-exon (hEx) replacement mouse strains in which a mouse (m)Cftr exon-of-interest was replaced with the corresponding human exon's sequence were designed. hEx replacement strains carrying either human exon 3, 11, 12, or 26 expressed chimeric Cftr from the endogenous mCftr locus. WT hEx3, hEx11, hEx12, and hEx26 strains displayed phenotypes similar to non-chimeric WT controls and highly dissimilar to CF mice. Additionally, a mouse model containing the W1282X mutation in the mCftr gene was created. W1282X mice recapitulated common CF manifestations including low Cftr mRNA expression, poor survival and growth, and altered electrophysiology in various tissues. Forskolin induced swelling (FIS) was performed on intestinal organoids derived from the W1282X mouse and an existing G542X mouse treated with various pharmacologics. Both organoids demonstrated FIS upon treatment with readthrough agents, nonsense-mediated decay inhibitors, and CFTR modulators; however, the specific drug combinations that elucidated the most robust rescue differed in W1282X and G542X organoids. Discussion: The hEx replacement mice provide a novel genetic approach for creating humanized mouse models. hEx 3, 11, 12, and 26 strains displayed WT phenotypes with no evidence of CFTR dysfunction therefore validating the hEx approach for modeling CF mutations. The W1282X mouse is the first W1282X-specific in vivo CF model. It (open full item for complete abstract)

Committee: Craig Hodges (Advisor); Ronald Conlon (Committee Chair); Kimberly McBennett (Committee Member); Hua Lou (Committee Member); Mitchell Drumm (Committee Member) Subjects: Biomedical Research; Genetics; Molecular Biology

Master of Science, The Ohio State University, 1970, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 2008, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science (MS), Bowling Green State University, 2024, Biological Sciences

Muco-obstructive illness is caused by any number of defects in the respiratory tract that result in viscous or static mucus. This creates an environment conducive for pathogen colonization with subsequent synergistic interactions that drive selection of a smaller set of apex pathogens, resistant to immune and antibiotic intervention. Successful control and potential resolution of such infections will require the development of new therapeutic strategies. One potential approach involves identification of bacterial viruses that target the dominant bacterial strains that manifest in patients with compromised respiratory functions. This study considers a set of bacteriophage specific for, and toxic to Burkholderia species that often dominate in such patient populations. I isolated a set of bacteriophage from environmental samples (including soil, human sewage, and agricultural waste for consideration. Some environmental isolates were capable of infecting pathogenic Burkholderia and a suite of lab adapted and pathogenic Burkholderia strains. As a result of this bacteriophage hunt, 15 potential bacteriophage isolates have been maintained, four of which have been sequenced and analyzed further. To do so, DNA was extracted from the purified and amplified isolates and sequenced. Thus, it was postulated that the novel bacteriophages “Clear “and “Cloudy” may be related to the P2-family of bacteriophage: whereas novel bacteriophage “P1P” contains elements similar to mu-like phage. Further research is necessary to detail the genome structure, genetic relationships, and gene function; however, these novel isolates reiterate the notion that pathogen-infecting bacteriophage are potentially isolated from the environment using non-pathogenic or pathogenic strains.

Committee: Raymond Larsen Ph.D. (Committee Chair); Hans Wildschutte Ph.D. (Committee Member); Simon Morgan-Russell Ph.D. (Committee Member) Subjects: Microbiology

PhD, University of Cincinnati, 2024, Medicine: Pathobiology and Molecular Medicine

Heart disease continues to be the number one killer in the United States accounting for 1 in every 9 deaths. Furthermore, over 6 million people are currently living with heart failure in the US, costing 30 billion dollars each year. In essence, heart disease develops because the cardiac tissue, unlike skeletal muscle or skin, lacks a robust regenerative capacity. Thus, an ischemic injury to the heart almost always results in a permanent loss of cardiac myocytes, inducing a cascade of pathological responses that result in interstitial fibrosis, loss of ventricular compliance, and chamber remodeling. For years, development of new therapies to cure heart failure has primarily focused on the repair and replacement of cardiomyocytes since they constitute most of the heart by volume and are the fundamental contractile cells that generate the force to pump blood to the body. However, more and more studies are now showing the importance of noncardiomyocytes and their interactions with cardiomyocytes in maintaining cardiac homeostasis during health and disease. In fact, recent calculations show that cardiomyocytes account for only 30% of the total cell count in the adult mouse with the majority represented by supportive cell populations such as endothelial cells, hematopoietic-derived cells, fibroblasts, and smooth muscle cells. This new avenue of non-cardiomyocyte biology is at the forefront of the efforts in developing new therapies to treat heart disease which requires extensive research to decipher the relevance and the role of these non-myocyte populations in homeostasis, disease, and injury to the heart.

Committee: Onur Kanisicak PhD (Committee Chair); David Askew Ph.D. (Committee Member); Yi-Gang Wang M.D. (Committee Member); Katherine Yutzey Ph.D. (Committee Member); Michael Tranter Ph.D. (Committee Member) Subjects: Cellular Biology

Master of Science, The Ohio State University, 2024, Immunology and Microbial Pathogenesis

Nontuberculous mycobacteria (NTM) are an increasingly common cause of respiratory infection in people with cystic fibrosis (PwCF). Relative to those with CF and no history of NTM infection (CF-NTMNEG), PwCF and a history of NTM infection (CF-NTMPOS) are more likely to develop severe lung disease, experience complications over the course of treatment and are precluded from lung transplant eligibility. We recently reported lung lobe-specific immune profiles of 3 cohorts (CF-NTMNEG, CF-NTMPOS and non-CF adults) and found that the CF-NTMPOS airways are distinguished by accumulations of B cells produced. Confirming the presence of antibodies, in the bronchioalveolar fluid (BAL), would prove a mechanistic connection between B cell abundance and lung tissue damage. This would be due to an overreactive antibody response or the abundance of antibodies being able to exacerbate pulmonary damage. This is caused by the release of cytokines and other inflammatory signals to recruit more immune cells to the site. We anticipate these findings will lead to the development of a clinical diagnosis of NTM infection and the creation of host-directed therapies to improve NTM disease treatment in PwCF. We hypothesize that the presence of total antibodies in BAL for these three cohorts will provide a mechanistic connection to the exacerbation of lung tissue damage in PwCF and a concurrent NTM infection.

Committee: Richard Robinson PhD (Advisor); Emily Hemann PhD (Committee Member); Adriana Forerro PhD (Committee Member); Mark Drew PhD (Advisor) Subjects: Health Care; Immunology; Microbiology; Molecular Biology

Doctor of Philosophy, The Ohio State University, 2024, Biomedical Sciences

Heart disease remains the leading cause of death in the United States with heart failure specifically accounting for 13.4% of all heart disease-related deaths. In 2019, Andersson et al., utilized a multi-omics approach to evaluate participant samples from the Framingham Heart Study and showed that ankyrin-R (AnkR; encoded by ANK1) is associated with diastolic function, left ventricular remodeling and heart failure with preserved ejection fraction. Ankyrins are a family of proteins that link integral membrane proteins with the actin/β-spectrin cytoskeleton. Ankyrins-B/G have been extensively studied and identified within the heart and their dysfunction is associated with cardiac structural and electrical phenotypes. Ankyrin-R, first identified in erythrocytes, has yet to be studied in the context of cardiac function, heart failure or arrhythmias. To study AnkR in the context of the heart we isolated tissues from adult wild-type mice as well as isolated myocytes and cardiac fibroblasts and performed immunoblot and qPCR analysis for ankyrin-R protein and Ank1 mRNA expression. Concurrently, we generated an Ank1-cKO mouse to genetically delete canonical AnkR in cardiomyocytes under the αMHC promoter. We found that isolated cardiomyocytes express only the small AnkR isoform while cardiac fibroblasts express the canonical large AnkR isoform at both the protein and mRNA level. Canonical AnkR is diffusely expressed in the fibroblast membrane, cytoplasm, cytoskeleton, and soluble nuclear fractions. Further, when AnkR is knocked out of cultured fibroblasts we observed a significant decrease in contractility. When we generated an Ank1-ifKO mouse model to selectively delete AnkR in activated fibroblasts, we observed no significant increase to fibrotic deposition after AngII/PE challenge. These results are the first to show canonical AnkR expression specifically within the cardiac fibroblasts and the loss of AnkR, coordinating with Golgi machinery, reduces the amount and changes (open full item for complete abstract)

Committee: Peter Mohler (Advisor); Sara Koenig (Advisor); Mona El Refaey (Committee Member); Thomas Hund (Committee Member); Sakima Smith (Committee Member) Subjects: Biomedical Research; Cellular Biology; Molecular Biology

PhD, University of Cincinnati, 2023, Medicine: Biostatistics (Environmental Health)

In recent years, advancements in real-time prediction have been achieved by introducing a more flexible term representing a non-stationary stochastic process to replace the classic random slope in the linear mixed effects models. The resulting model has been used to form predictive probabilities for clinically relevant target functions involving rates of change in the mean response function for people with cystic fibrosis (CF). However, data patterns are changing over time, especially with the introduction of ivacaftor treatment in 2012 followed by other highly effective modulator therapies. In this dissertation, I focused on evaluating the epidemiologic impact of secular trends in CF care and treatments on acute lung decline prediction and characterized the changing patterns. Specifically, I evaluated the performance of predicting rapid lung decline events through a novel data-driven definition. There are often multiple, related, noisily-measured outcomes that are critical to monitoring and predicting disease progression of individuals over time. However, the current approach has been limited to a single outcome. Considering the case of two outcomes, I propose a bivariate mixed effects model utilizing integrated Brownian motion for each mean response function. Estimation of the proposed model was implemented through a combined approach of the Newton-Raphson and Fisher Scoring algorithm and profile likelihood. I also propose a bivariate target function that simultaneously predicts under the two-outcome scenario based on clinically meaningful thresholds of rates of change. This novel approach is applied to achieve real-time prediction of key changes in nutrition and lung function for children with CF who are followed in a national patient registry.

Committee: RhondaRhonda SzczesniakSzczesniak Ph.D.Ph.D. (Committee Chair); Marepalli Rao Ph.D. (Committee Member); Roman Jandarov Ph.D. (Committee Member); Richard Brokamp Ph.D. (Committee Member); Marepalli Rao Ph.D. (Committee Member) Subjects: Biostatistics

MS, University of Cincinnati, 2023, Engineering and Applied Science: Biomedical Engineering

Schwann cells (SCs) are responsible for axon function and maintenance in the peripheral nervous system (PNS), as well as being a key component to the regeneration process following trauma. Once an injury occurs, SCs respond to both physical and chemical stress cues to modify their phenotype to assist in the regeneration of damaged axons. There is currently a lack of research examining SC response to dynamic changes in the extracellular matrix (ECM) brought on by swelling and the development of scar tissue as part of the body's wound-healing process. Thus, the overall objective of this project is to use a biocompatible, mechanically tunable substrate to mimic changes in the microenvironment. Previously, we have reported that ECM cues such as ligand type and substrate stiffness impact SC phenotype and plasticity, which was demonstrated by culturing SCs on mechanically stable substrates. However, to better realize SC potential for plasticity following traumatic injury, we utilized a UV-tunable PDMS substrate with dynamically changing stiffness to mimic changes in the microenvironment. Through the examination of cell morphology and protein expression, we seek to better understand the relationship between SC plasticity and a dynamically changing microenvironment in both injury and diseased states. This relationship holds the potential for creating future PNS therapies that currently have extremely limited methods of care.

Committee: Greg Harris Ph.D. (Committee Chair); Jason Shearn Ph.D. (Committee Member); John Martin Ph.D. (Committee Member) Subjects: Biomedical Engineering

Bachelor of Science (BS), Ohio University, 2023, Biological Sciences

Fibrosis, a pathological process characterized by excess extracellular matrix (ECM) deposition, can occur in many internal organs and tissues in response to various stimuli. As fibrosis progresses, scarring occurs, which ultimately leads to tissue dysfunction and organ failure. Patients with acromegaly, a rare disease usually caused by a benign, GH-producing pituitary tumor, have been reported to have prominent ECM deposition and scarring in certain tissues, which is indicative of fibrosis. In bGH transgenic mice, which express high levels of bovine growth hormone, several tissues [white adipose tissue (WAT), heart, intestine, and kidney] demonstrate a fibrotic phenotype. However, there is no previous research that investigates various bGH tissues – particularly from mice derived from a single cohort – for fibrosis. Additionally, WAT fibrosis is associated with obesity and lipodystrophy, and seems to be particularly associated with excess GH. This study aims to investigate the role of different cell types and genes involved in the development and progression of WAT fibrosis and determine if fibrosis is increased in BAT, liver, quad, kidney, lung, and spleen of aged bGH mice. Results of this thesis included a striking observation of increased fibrosis in all bGH tissues examined. For WAT, decreases in fibrosis-associated RNA expression in 3-month-old bGH mice via qPCR analysis was only observed in the perigonadal depot and not the subcutaneous depot that has more prominent collagen deposition. Interestingly, we observed an intriguing increase in fibrosis-associated RNA expression in a population of adipose stem and progenitor cells in 6-month-old mice within subcutaneous bGH WAT. These results indicate a potential common GH-induced mechanism of fibrosis across bGH tissues and pave the way for future research into WAT fibrosis.

Committee: Darlene Berryman (Advisor) Subjects: Biology; Biomedical Research

MS, University of Cincinnati, 2023, Engineering and Applied Science: Biomedical Engineering

Debilitating lung diseases such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF) are highly problematic yet have etiologies that are poorly understood. This establishes a role for noninvasive diagnostic techniques that can characterize the structure and function of the lungs. To that end, developments in magnetic resonance imaging (MRI) have shown promise in providing high-resolution images using multiple types of contrast in the lungs without delivering ionizing radiation. MRI in the lungs has traditionally been viewed as a challenge due to rapid apparent transverse relaxation (characterized by the rate constant T2*) accelerated by magnetic susceptibility gradients at the alveolar air-tissue interfaces and a lack of tissue density. Fortunately, the short T2* constraint can be addressed by 1H ultrashort echo time (UTE) sequences which enable imaging at echo times on the order of tens of microseconds. Additionally, imaging exogenous agents such as inhaled hyperpolarized (HP) 129Xe gas overcomes low pulmonary tissue density, offering diffusion-weighted contrast useful for characterizing the lung microstructure. When paired with robust preclinical models such as transgenic models of pulmonary fibrosis, these techniques allow lung MRI to provide important insight into the emergence and etiologies of these chronic diseases. This thesis describes validations and improvements for two methods in preclinical lung MRI. First, we validated retrospectively gated 1H UTE T2* mapping as a method to track disease progression in a mouse model of progressive pulmonary fibrosis. Pulmonary T2* is a novel, quantitative contrast that does not depend on imaging parameters such as coil shading. Additionally, we developed an image processing and analysis methodology that automates the production of whole lung T2* maps from UTE MRI data. Second, we investigated the effects of card (open full item for complete abstract)

Committee: Zackary Cleveland Ph.D. (Committee Member); T. Douglas Mast Ph.D. (Committee Member); Jing-Huei Lee Ph.D. (Committee Member) Subjects: Radiology

Doctor of Philosophy (PhD), Wright State University, 2023, Biomedical Sciences PhD

With its incorporation into clinical practice in the early 1980s, the class of pharmacological agents known as calcineurin inhibitors (CNIs) quickly became the cornerstone of immunosuppressive therapy post-organ transplantation. However, its use is limited by irreversible kidney damage in the form of renal fibrosis. The molecular mechanism by which CNIs induce renal fibrosis remains to be better understood, and to date, there are no specific therapeutic strategies to mitigate this damage. This dilemma presents a critical need to explain mechanisms by which CNIs cause renal damage. Kidneys of patients on chronic CNI therapy show increased expression of the proinflammatory cytokine Transforming Growth Factor β (TGFβ). TGFβ is a multipotent regulator of cell survival, differentiation, proliferation, and extracellular matrix (ECM) production in a variety of tissues. Renal biopsy samples from patients with tacrolimus nephrotoxicity showed both increased mRNA and protein expression of TGFβ along with fibronectin and collagen, additional profibrotic markers. However, the role of TGFβ signaling in CNI-induced renal damage remains to be defined and this gap in knowledge prompts further investigation. To this end, this dissertation will I) determine the role of TGFβ signaling in CNI-induced renal damage (Aim 1) and II) establish whether disruption of TGFβ signaling ameliorates renal damage with CNI-induced immunosuppression (Aim 2). This insight will direct development of newer generation CNI immunosuppressants exhibiting reno-preservative potential. Our group reported that aberrant Transforming Growth Factor-β (TGFβ)/Smad signaling drives the profibrotic effects induced by CNIs. Specifically, we demonstrated that 1) tacrolimus inhibits the calcineurin/NFAT axis while inducing TGFβ ligand secretion and receptor activation in renal fibroblasts, 2) aberrant TGFβ receptor activation stimulates Smad-mediated production of myofibroblast markers, notable features of fibrobla (open full item for complete abstract)

Committee: Clintoria Williams Ph.D. (Advisor); Mark Rich M.D., Ph.D. (Committee Member); Eric Bennett Ph.D. (Committee Member); David Cool Ph.D. (Committee Member); Khalid Elased Pharm.D., Ph.D. (Committee Member) Subjects: Biology; Biomedical Research; Medicine; Pathology; Pharmacology; Physiology

PhD, University of Cincinnati, 2022, Medicine: Biostatistics (Environmental Health)

Cystic fibrosis (CF) is an autosomal recessive disorder affecting approximately 30,000 people in the United States. Patients with CF develop chronic lung infections and develop recurrent respiratory symptoms called pulmonary exacerbations (PE). Individual PE symptoms may substantially vary according to changes in lung function, nutrition and other clinical factors, and there is no consensus on timely treatment initiation. The Early Intervention in Cystic Fibrosis Exacerbation Study (eICE) was designed to determine whether early treatment of PE events is beneficial. To mitigate exacerbations, it is important to identify and control specific environmental factors such as climate and air pollution. We develop a case-crossover design to evaluate whether pulmonary exacerbations are associated with daily fluctuations in weighted PM2.5 estimates. The case-crossover design allows for temporal variables between case and control periods and controls for many potential confounders that do not change in the conditional logistic regression model. Our results demonstrate a positive association between daily weighted PM2.5 estimates and the prevalence of pulmonary exacerbations with a suitable washout period. Lag models capture the exposure effect up to three days prior to the onset of these exacerbations. The advantages, issues, and possible solutions of implementing a case-crossover design are also investigated. Several important drawbacks of the case-crossover study design require the understanding of the mechanics why CF patients develop PE events. We develop a simulation to replicate the case-crossover eICE study to examine the effects of the prevalence of PE events by a participants baseline risk, PM2.5, effect size, and washout. The case-crossover simulation generates cases by following a cohort of individuals with CF every day and then implements the case-crossover design to summarize the association between pulmonary exacerbation prevalence and PM2.5 exposure. We c (open full item for complete abstract)

Committee: Marepalli Rao Ph.D. (Committee Member); Rhonda Szczesniak Ph.D. (Committee Member); Richard Brokamp Ph.D. (Committee Member) Subjects: Environmental Health

MS, University of Cincinnati, 2022, Medicine: Biostatistics (Environmental Health)

BACKGROUND: Environmental exposures and community characteristics have been linked to rapid lung function decline and other adverse pulmonary outcomes in people with cystic fibrosis (CF). Geomarkers, the measurements of these exposures, have been linked to patient outcomes in other respiratory diseases, though broad-based geomarker studies are lacking and it is unknown which geomarkers will have the greatest predictive potential for rapid decline and pulmonary exacerbation (PEx) in CF. OBJECTIVE: A retrospective longitudinal cohort study was performed to determine whether and which geomarkers would be chosen via novel Bayesian joint covariate selection approaches and to compare the predictive performance of the resultant models for onset of PEx. METHODS: Non-stationary Gaussian linear mixed effects models were fitted to data from 151 cystic fibrosis patients aged 6 – 20 receiving care at the Cincinnati Children's Hospital Cystic Fibrosis Center (2007-2017). The outcome of interest was forced expiratory volume in 1 second of percent predicted (FEV1pp). Target functions were used to predict PEx onset according to an established definition based on drops in FEV1pp. Covariates included 11 clinical/demographic characteristics (age, sex, number of PEx-defined events within previous year, F508del mutation, pancreatic insufficiency, MEDICAID insurance use, BMI percentile, PA infection, MRSA infection, CF-related diabetes mellitus, and the number of hospital visits within the previous year), and 45 geomarkers comprising 8 categories (socioeconomic status, access to care, roadway proximity, crime, land cover, impervious descriptors, weather, and air pollution). Joint selection of covariates for predictive models was achieved using four Bayesian penalized regression models (elastic-net, adaptive lasso, ridge, and lasso). Unique covariate selections at both the 95% and 90% credible intervals (CIs) were fit to a linear mixed effects model with non-stationary stocha (open full item for complete abstract)

Committee: Marepalli Rao Ph.D. (Committee Member); Rhonda Szczesniak Ph.D. (Committee Member) Subjects: Statistics

PhD, University of Cincinnati, 2022, Arts and Sciences: Mathematical Sciences

Joint modeling has been a useful strategy for incorporating latent associations between different types of outcomes simultaneously in the last two decades. This dissertation contributes to the development of a multilevel Bayesian joint model, which is motivated by a longitudinal lung disease study. In Chapter 1, the background of Bayesian methodology for the joint modeling is introduced. Chapters 2 and 3 describe two novel joint models with applications to the multi-center data for cystic fibrosis disease. First, in Chapter 2, a multilevel Bayesian joint model of longitudinal continuous and binary outcomes is proposed. Second, in Chapter 3, a multilevel Bayesian joint model of longitudinal and recurrent outcomes is postulated. Lastly, in Chapter 4, some key takeaways, limitations and future work are discussed.

Committee: Seongho Song Ph.D. (Committee Member); Won Chang Ph.D. (Committee Member); Xia Wang Ph.D. (Committee Member); Rhonda Szczesniak Ph.D. (Committee Member); Hang Joon Kim Ph.D. (Committee Member) Subjects: Statistics

Doctor of Philosophy, The Ohio State University, 2022, Biomedical Sciences

The skeletal muscle plays a vital role in the mammalian muscle system allowing for force production and movement. At the core of the skeletal muscle is the myofiber which represents the contractile unit. Satellite cells are skeletal muscle stem cells which retain the ability to replicate in mature muscles allowing recovery from the routine daily stress. In adult skeletal muscle, a harmonious balance between the presence of satellite cells and their extracellular matrix is essential to maintain their function. Injuries which disturb this balance decrease the ability of the skeletal muscle to recover from injury. An example of such an injury is volumetric muscle loss which results in extensive disfigurement, disability, and handicap, owing to a destruction of satellite cells and of the environment that nurtures their growth. Research of factors that can mitigate sequalae of volumetric muscle loss is ongoing. Ideal candidates would be endogenous to reduce immunologic reactions in therapeutic application. MG53 is a protein ubiquitous in skeletal muscle. Multiple functions of the protein have been identified. In the present study, we evaluate the role of MG53 in the skeletal muscle during recovery following volumetric muscle loss using a murine model. We find pronounced functional deficits in the absence of MG53 and confirm a role in skeletal muscle in ameliorating pathology following volumetric muscle loss injury. Evaluation of acute and chronic wounds following volumetric muscle loss reveals that the presence of MG53 results in a reduction in fibrosis, necrosis, and an improvement in regeneration characterized in the early days following injury by an increase in the number of satellite cells, an increase in the size of regenerated myofibers, as well as lipid mediators known to improve myoblast proliferation, differentiation, cell survival and fusion. Additionally, MG53 tilts the balance between recovery and fibrosis in favor of regeneration by mitigating TGFβ media (open full item for complete abstract)

Committee: Jianjie Ma (Committee Chair); Peter Lee (Advisor); Ginny Bumgardner (Committee Member); Rhenzi Han (Committee Member); Chuanxi Cai (Committee Member) Subjects: Biomedical Engineering; Biomedical Research