Medicine and Health Sciences Commons^™

The Impact Of Simulated Image Acquisition Time Reduction On Image Quality And Parameters Of Myocardial Perfusion Imaging Using A Dedicated Cardiac Camera, Alireza Khatami

Electronic Thesis and Dissertation Repository

Heart disease is the second leading cause of death in Canada, highlighting the crucial role of early diagnosis in disease management. Myocardial perfusion imaging (MPI), is widely employed for this purpose, involves injecting a radiopharmaceutical into the body, imaging its distribution with a gamma camera, and revealing cardiac blood flow patterns. A significant challenge in MPI is the lengthy 8 to 10 minutes required for stress and rest imaging, potentially causing patient discomfort and compromising image quality due to movement. In a clinical study with 26 patients, post-processed data manipulation simulated a reduction in MPI imaging time. The findings indicated …

Interaction Of Circularrna And Microrna-9-5p In The Mediation Of Cardiac Fibrosis In Diabetic Cardiomyopathy, Honglin Wang

Electronic Thesis and Dissertation Repository

Diabetic cardiomyopathy (DCM) is a chronic diabetic complication affecting the heart. It is a significant and independent contributor to heart failure and characterized by cardiac fibrosis and left ventricular hypertrophy. Endothelial cells are the first cells to be damaged by hyperglycemia, leading to epigenetic modifications and subsequent signaling and transcription derangements that lead to endothelial dysfunction and therefore cardiac fibrosis. The role of the two noncoding RNA microRNA-9-5p and circRNA_012164 are investigated using in vivo and in vitro models of hyperglycemia. CircRNA_012164 is upregulated in the hearts of diabetic mice and in cells exposed to high glucose. This results in …

Multi-Arm Randomized Control Trials In Inflammatory Bowel Disease: A Literature Review And An Illustration Of Methods For Analysis, Sahiba Saini

Electronic Thesis and Dissertation Repository

This thesis aimed to review the literature on multiple-arm randomized control trials in inflammatory bowel disease (IBD) and to illustrate how to analyze these trials, focusing on appropriately controlling the type 1 error rates. The literature review found 247 trials published from the inception of each database to April 2014, of which 122 (49%) trials were multiple-arm trials and of those, 59 (48%) trials were on ulcerative colitis and 63 (52%) on Crohn’s disease. A published assessment tool was adopted to assess whether controlling of Type I error rates was needed. Despite the common use of this trial design and …

Assessing Copd Care Quality In A Rural Ontario Primary Care Clinic: A Retrospective Chart Review, Daniel Henke

Electronic Thesis and Dissertation Repository

Background: Primary chronic obstructive pulmonary disease (COPD) care may be worse in rural versus more urban environments.

Purpose: To evaluate the quality of COPD care in a rural Ontario primary care clinic.

Methods: A 12-month retrospective chart review study was conducted between June 2022 and January 2023 at a Goderich, Ontario primary care clinic. Electronic medical records (EMRs) were randomly selected for inclusion. Baseline sociodemographic (e.g., occupation) and health (e.g., smoking status) characteristics were extracted as well as information regarding COPD care received (i.e., Health Quality Ontario [HQO] Quality Standard [QS] indicators; n=33. The primary study outcome was overall proportion …

Social Supports For Adolescent And Young Adult Polycystic Ovary Syndrome Patients: A Scoping Review, Caitlin E. Mungall

Western Libraries Undergraduate Research Awards (WLURAs)

Polycystic ovary syndrome (PCOS) is a chronic disorder with negative health consequences for millions of women. The paucity of research regarding interventions targeting the psychosocial symptoms of PCOS for adolescents and young adults (AYAs), susceptible to low self-esteem and depression, warranted this review. This paper provides an overview of research on the social supports currently available for AYAs and identifies areas where further research is required to elucidate their support needs. A scoping review methodology identified 15 studies that met inclusion criteria. Findings revealed that this is an emerging field of research and most included studies originated in North America. …

The Impact Of Access To Oral Health Care On Inadequate Oral Health And Multimorbidity, Luis Limo

Electronic Thesis and Dissertation Repository

The connection between oral health and other non-communicable chronic conditions—commonly referred in the dental literature as the oral-systemic health connection—emphasizes the role of oral health care on both oral diseases and chronic conditions, particularly in vulnerable populations like the elderly. This thesis comprises 2 studies: the first is a systematic review on the impact of oral health care interventions, as an indicator of access to oral health care, on chronic conditions of which their co-existence would result in multimorbidity; the second study is a cross-sectional investigation of the associations between oral health, access to oral health care, and multimorbidity among …

Exploring The Experience Of Sexuality And Gender During The Healthcare Transition Of The Youth With Cerebral Palsy, Umma Salma

Electronic Thesis and Dissertation Repository

Background: Transition from the pediatric to adult health care system is an important phase of healthcare for youth with cerebral palsy (CP). Sexuality and gender are two very important components of health that are mostly ignored in the healthcare transition process. It is possible that health care providers only see a client’s disability, and therefore, key aspects of sexuality and gender diversity may be ignored, or deemed irrelevant as a result of their disability status. Therefore, the purpose of our study is to explore how gender and sexuality may influence the experience of health care transition for youth with cerebral …

Role Of Circular Rna Asph In Macrophage Polarization And Response In Sepsis, Tan Ze Wang

Electronic Thesis and Dissertation Repository

Circular RNAs (circRNAs), a novel non-coding RNA species generated by back-splicing, has been shown to participate in gene regulation of leukocytes. Our previous RNA sequencing results show circular RNA ASPH (circASPH) to be highly expressed in peripheral blood mononuclear cells of sepsis patients at the start of intensive care. Macrophages, as ubiquitous innate immune cells, are responsible for the recruitment of other immune cells at sepsis onset. This work investigates the role of circASPH in the regulation of macrophage polarization in sepsis. Using an in vitro THP-1 cell model, it was found that circASPH levels peaked after 24 h of …

Sex Differences In Mood And Anxiety-Related Outcomes In Response To Adolescent Nicotine Exposure, Tsun Hay Jason Ng

Electronic Thesis and Dissertation Repository

Nicotine dependence is causally linked to increased risk of mood/anxiety disorders in later life. Females are reported to experience a higher prevalence of anxiety/depressive disorders and challenges in smoking cessation therapies, suggesting a potential sex-specific response to nicotine exposure and mood/anxiety disorder risk. However, pre-clinical evidence of sex-specific responses to adolescent nicotine exposure is unclear. Thus, to determine any sex differences in anxiety/depressive-related outcomes, adolescent male and female Sprague Dawley rats received nicotine (0.4 mg/kg; 3x daily) or saline injections for 10 consecutive days, followed by behavioural testing, in-vivo electrophysiology and Western Blot analyses. Our results revealed that adolescent nicotine …

Pannexin3 In Exercise, Obesity, And Osteoarthritis, Brent Wakefield

Electronic Thesis and Dissertation Repository

Pannexin 3 (PANX3), is a glycoprotein that oligomerizes to form mechano-sensitive channels expressed in musculoskeletal tissues, and has been identified as a potential target for the treatment of obesity and osteoarthritis (OA). Obesity and OA are two of the most prevalent diseases worldwide, leading to disability and even death. These conditions are thought to originate from a complex interaction between genetics, aging, sex, and modifiable lifestyle factors, such as exercise. Investigating the interactions between genetic and exercise may provide a more comprehensive, context-specific understanding of gene function. This thesis aimed to understand the interactions between PANX3 and exercise interventions on …

The Combined Effects Of Physical Exercise And Cognitive Training On Gait Speed And Primary Motor Cortex Metabolism In Individuals With Mild Cognitive Impairment: A 1h-Mrs Analysis, Jack Thomas Emsey Elkas

Electronic Thesis and Dissertation Repository

Mild cognitive impairment (MCI) is a transitional stage before dementia. Altered gait in MCI has been associated with progression to dementia. Using magnetic resonance spectroscopy, a relationship between primary motor cortex (M1) neurochemistry and dual task gait speed has been reported in MCI. Interventional research suggests exercise, cognitive training, and vitamin D supplementation may benefit MCI, yet the combined effect of these treatments on gait speed and M1 metabolism is unknown. Participants with MCI (N=75) were assigned to one of five intervention arms and dual task cost on gait speed and M1 metabolism was assessed before and five months after …

Do Clinical Exercise Tests Permit Exercise Threshold Identification In Patients Referred To Cardiac Rehabilitation?, Randi R. Keltz

Electronic Thesis and Dissertation Repository

The purpose of this thesis was to quantify the proportion of patients whose clinical cardiopulmonary exercise test (CPET) permitted identification of estimated lactate threshold (θ_LT) and respiratory compensation point (RCP) and to characterize the variability at which these thresholds occur to evaluate the feasibility of “threshold-based” aerobic exercise prescription. We retrospectively analyzed CPET data of 1102 patients (65±12 yrs; 306 females) referred to cardiac rehabilitation. θ_LT and RCP were identified and reported as oxygen uptake (V̇O₂), heart rate (HR), %V̇O_2peak, and %HR_peak. Patients were grouped by threshold identification: group 0) neither …

Mining Sars-Cov-2 Phylogenetic Trees To Estimate Circulating Infections And Patterns Of Migration, Erin V. Brintnell

Electronic Thesis and Dissertation Repository

The SARS-CoV-2 pandemic led to the formation of very large databases of genomic viral data. These databases contain information on transmission dynamics, emergence and evolution of SARS-CoV-2. However, extracting this information from sequences is difficult, as most methods of analyzing viral genomes were developed for smaller data sets. Therefore, my objective was to develop new fast estimators of the number of infections (I) and the rate of migration based on simple features of SARS-CoV-2 phylogenies.

I simulated pathogen evolution using a susceptible-exposed-infectious-recovered (SEIR) model of pathogen spread, reconstructing evolution using CoVizu. For simulations of I, I varied the total number …

Assessing Inflammation In The Pathology Of Knee Osteoarthritis, Zachary J. Koudys

Electronic Thesis and Dissertation Repository

Osteoarthritis (OA) is a joint disease that causes pain, stiffness, and loss of function. Inflammation of the synovium plays a role in the pathology of OA. Macrophages are the dominant immune cells in synovial tissue. Activated macrophages over-express the translocator protein (TSPO). [¹⁸F]FEPPA is a 2^nd generation positron emission tomography (PET) tracer that can target TSPO with high specificity. Hybrid [¹⁸F]FEPPA PET/MRI may enable accurate quantification of macrophage activity in vivo. In this work, [¹⁸F]FEPPA tracer uptake in knee synovial tissue was measured ex vivo using autoradiography and was validated to correlate to …

Sarcopenia In Head And Neck Cancer: A Prognostic Analysis, Nedeljko Jovanovic

Electronic Thesis and Dissertation Repository

Introduction: In head and neck cancer (HNC), loss of skeletal muscle mass (SMM), or sarcopenia, is a strong prognostic factor for outcomes. However, inconsistencies in its assessment limit our understanding of the relationship between sarcopenia and nutrition-related outcomes. This project evaluated the significance of sarcopenia as described in the literature and as demonstrated in a cohort of HNC patients.

Methods: A scoping review was first conducted followed by a retrospective cohort study with data collected from 194 oropharyngeal carcinoma patients treated with definitive radiation/chemoradiation. Sarcopenia was assessed from computed tomography (CT) imaging at the third cervical vertebra (C3) and the …

Lipoprotein(A), Oxidized Phospholipids, And Vascular Smooth Muscle Cell Phenotype And Viability, Michael Dunphy

Electronic Thesis and Dissertation Repository

Genetic studies have shown elevated plasma lipoprotein(a) (Lp(a)) levels to be an independent and causal risk factor for atherosclerotic cardiovascular disease and calcific aortic valve disease, however a definite mechanism for this pathogenicity has yet to be clearly identified. Oxidized phospholipids (oxPLs) have been implicated in facilitating atherogenic changes in the gene expression of vascular cells. As the primary carrier of oxPLs in the plasma, we hypothesize that Lp(a) contributes to vascular diseases by its enhanced ability to bind to and deliver oxPLs to tissue through a strong lysine binding site on its apolipoprotein(a) (apo(a)) component. Using a cultured primary …

Characterizing The Function Of B Cells That Accumulate In The Inflamed Central Nervous System In Anti-Myelin Autoimmunity, Lika Chowdhury

Electronic Thesis and Dissertation Repository

While the role of autoimmune T cells has been extensively studied in anti-myelin

autoimmunity, little is known about the function of B cells in multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system (CNS). B cells form clusters with T cells in the meninges directly adjacent to demyelinating lesions. Previous studies have shown that disease progression is dependent on the depletion of specific populations of B cells, but it is not clear which contributes to pathology or how. The purpose of this thesis is to characterize the population of meningeal B cells to determine how they differ …

Monitoring Intraventricular Hemorrhage In Preterm Infants, Lilian Mn Kebaya

Electronic Thesis and Dissertation Repository

Germinal Matrix-Intraventricular hemorrhage (GMH-IVH) remains a significant cause of adverse neurodevelopmental outcomes in preterm infants. Current management options for GMH-IVH rely on serial 2-dimensional cranial ultrasound (2D cUS) ventricular measurements and clinical signs. A need exists for reliable biomarkers to aid in the early detection of posthemorrhagic ventricular dilatation (PHVD) and cerebral palsy (CP). We incorporated 3-dimensional cranial US (3D cUS) and functional infrared spectroscopy (fNIRS) to monitor ventricle volumes (VV) and spontaneous functional connectivity (sFC) in preterm infants with GMH-IVH. Infants with severe GMH-IVH who underwent cerebrospinal fluid diversion showed larger VV, which correlated with decreased sFC. Our findings …

Noninvasive Quantification Of Tissue Sodium Concentration In The Kidney Disease Spectrum Using 23na Magnetic Resonance Imaging, Fabio R. Salerno

Electronic Thesis and Dissertation Repository

Chronic kidney disease (CKD), especially when requiring kidney replacement therapy (hemodialysis (HD) and peritoneal dialysis (PD)), is associated with extracellular water expansion with increased total body sodium. Sodium can also be accumulated in tissues independently of extracellular water. Sodium-23 magnetic resonance imaging (²³Na MRI) can quantify the concentration of sodium nuclei in tissues. Applied to the human leg, quantification of tissue sodium concentrations mainly at the skin and muscle level is possible. We hypothesized that increased tissue sodium concentrations exert toxic effects in CKD and dialysis. We aimed to (1) compare tissue sodium concentrations in adults, children and …

The Effect Of Oral And Topical Antibiotics On Foreskin Inflammation And Hiv Target Cells In Ugandan Men., Zhongtian (Eric) Shao

Electronic Thesis and Dissertation Repository

Penile circumcision reduces HIV susceptibility by up to 60% in men; however, many men prefer to remain uncircumcised for personal or cultural reasons. Penile circumcision protects against HIV by reducing anaerobic bacteria on the penis. Penile anaerobes cause local inflammation and the recruitment of HIV-susceptible CD4+CCR5+ cells, increasing the likelihood that exposure to HIV during intercourse results in infection. To determine if a non-surgical intervention can reduce penile anaerobes and HIV target cells, we randomized men to antimicrobial treatment prior to circumcision. To be able to quantify the effect of antimicrobials, we developed a novel deep-learning algorithm to quantify HIV …

Exploration Of The Pathophysiological Mechanisms Underlying Hemodialysis Associated Cardiac Ischemic Injury, Lisa Yun Jeong Hur

Electronic Thesis and Dissertation Repository

Hemodialysis (HD) provides life-saving treatment in individuals with kidney failure. However, HD is associated with poor quality of life and extremely high mortality rates mainly caused by cardiovascular disease due to heart failure and sudden cardiac death. Standard pharmacological treatment developed within the non-kidney disease community are largely ineffective in HD patients because of the difference in pathophysiology of cardiovascular mortality. HD treatment causes hypotension and recurrent ischemic injury to multiple vascular beds including the heart, leading to heart failure. These injuries can be abrogated by improving the patient’s tolerability of the treatment. To apply interventions that may improve hemodynamic …

Western Diet-Like Culture Conditions And Oxidative Stress On A Cell Model Of Non-Alcoholic Fatty Liver Disease, Celina M. Valvano

Electronic Thesis and Dissertation Repository

Non-alcoholic fatty liver disease (NAFLD) is a major health burden in the Western world, as the Western diet (WD) appears to be the driving force of this disease. However, the individual contributions of the diet and the impacts of their individual metabolism are currently ill-defined. This study used HepG2 cells to understand the impact of the individual components of WD in early NAFLD development under basal insulin levels. Specifically, nutrient-induced changes in reactive oxygen species (ROS) and signaling pathways, such as sterol regulatory element binding proteins (SREBPs), were examined to identify the root cause of steatosis development. High-fat and WD-exposed …

Technical Adaptations For Cardiac Sodium Mri, Taylor L. Marcus

Electronic Thesis and Dissertation Repository

Cardiac sodium (Na⁺) MRI has the potential to unveil relationships between chronic kidney disease (CKD) and cardiovascular disease (CVD). Unfortunately, this modality requires many technical adaptations before it’s possible to extract and compare image data between individuals. This study investigated whether cardiac electrocardiogram (ECG) gating could improve image quality, and whether a uniform phantom could increase signal uniformity if a surface coil is used to acquire the image. Healthy participants were imaged with a custom-built surface coil and 3.0-T MR system. Cardiac gated images presented with a decreased signal-to-noise ratio (SNR), but intensity correction significantly increased image signal …

Role Of Decorin At The Fetal-Maternal Interface, Chidambra D. Halari

Electronic Thesis and Dissertation Repository

The human placenta is an invasive tumor-like structure, this invasion being physiological. A subset of placental trophoblast called extra-villous trophoblast invades the uterine decidua and remodels uterine arteries into low-resistance, high-flow tubes to permit adequate flow of maternal blood to nourish the fetus. A poor extra-villous trophoblast invasion and uterine arterial remodeling can lead to fetal growth restriction and a serious pregnancy-associated maternal disease preeclampsia. Decorin, a leucine-rich proteoglycan produced by uterine decidual cells restrains multiple trophoblast functions: self-renewal and differentiation of trophoblast stem cells, migration, invasion, proliferation and endovascular differentiation. Additionally, decidual overproduction of decorin was associated with preeclampsia, …

Using A One Health Approach For The Assessment Of Rabies Control In Rural Victoria Falls, Zimbabwe, Ryan Lapenna

Electronic Thesis and Dissertation Repository

Rabies, a viral zoonotic disease, is widespread in Zimbabwe, with human fatalities reported annually in the country. To supplement the Government’s effort on rabies control, the Victoria Falls Wildlife Trust and Veterinarians for Animal Welfare Zimbabwe have joined forces to carry out dog rabies vaccinations in rural communities adjacent to the major tourist attraction of The Victoria Falls. A One Health approach was used to 1) determine the level of protective rabies antibodies among a sample of rural dogs and 2) collect information and describe the knowledge, attitudes, and practices related to rabies among dog owners. In 2020, blood was …

Ex-Smokers With And Without Copd: Investigating Ct Pulmonary Vascular, Airway, Pulmonary Artery And Aorta Measurements, Vedanth Desaigoudar, Paulina V. Wyszkiewicz, Alexander M. Matheson, Maksym Sharma, Marrissa J. Mcintosh, Harkiran K. Kooner, David G. Mccormack, Grace Parraga

Undergraduate Student Research Internships Conference

RATIONALE: Pulmonary hypertension is characterized by increased pressure in the pulmonary artery, and is a key contributor to worsening symptoms in individuals with chronic obstructive pulmonary disease (COPD). The pulmonary artery to aorta diameter ratio (PA:Ao), measured using computed tomography (CT), is a biomarker of pulmonary hypertension; however, longitudinal changes in this measurement and its relationship to pulmonary vascular and airway structural changes is not well understood. Our objective was to investigate longitudinal changes in PA:Ao and its relationship with CT pulmonary vascular and airway abnormalities, airflow limitation and exercise-capacity.

Resistance Training Improves White Matter Structural Connectivity In Older Adults At-Risk For Cognitive Decline, Ryu Lien

Undergraduate Student Research Internships Conference

Diabetes is a global health concern that impacts 415 million people worldwide. Individuals who are at-risk for diabetes (characterized by high blood glucose and/or being overweight) have white matter atrophy, decreased cognitive function, and an increased risk of Alzheimer’s disease (AD). Recently, resistance training (RT) has been shown to lower white matter atrophy and white matter lesion volume. However, investigating changes in white matter tracts is complex, hence previous findings remain inconclusive. Diffusion tensor imaging (DTI) serves as a highly sensitive tool that enables visualization and characterization of white matter tracts and has the potential to combat this complexity. The …

Rna Isolation In Duchenne Muscular Dystrophy (Dmd) Mice Models, Salem Abu Al-Burak

Undergraduate Student Research Internships Conference

Fibrosis is a progressive and typically irreversible disease process characterized by the excessive deposition of collagen in organs and in tissues of the musculoskeletal (MSK) system^1,2. This process, which causes loss of organ and tissue function, can be initiated by micro-traumas³, an excessive and/or prolonged immune response¹, the activation and proliferation of fibrosis-inducing progenitor cells⁴, and a pro-fibrotic extra-cellular microenvironment⁵. In parallel with the events that initiate fibrosis, genetic or environmental influences may cause cells and tissues to become predisposed to fibrosis development prior to initiation. This suggests that these …

Intracranial Eeg Patient Analysis: Seizure Reduction In Refractory Epilepsy Following Depth Electrode Insertion, Shreyashish Roy-Chowdhury

Undergraduate Student Research Internships Conference

Rationale: The implantation effect describes an immediate reduction in seizure frequency following the insertion of intracranial electrodes. There is limited information regarding which patients will experience a reduction of seizures and the reason for the implantation effect. This study focuses on describing predictor factors for the reduction in seizure frequency in patients with medically resistant epilepsy implanted with depth electrodes.

Methods: We conducted a retrospective chart review of 89 patients who underwent intracranial electroencephalography (iEEG) monitoring with depth electrodes. Sixty-five of these patients had no subsequent therapeutic interventions and had a 3-6 month follow-up. Patients were grouped as either responders …

Wellness Study: Functional Visual Outcomes In Eye Disease Patients Following The Covid-19 Pandemic, Andrew Maher

Undergraduate Student Research Internships Conference

The COVID-19 pandemic has caused delays in health services and medical appointments, affecting approximately one in three Canadian adults. Elderly eye disease patients experienced delays in treatment for eye conditions including cataracts, glaucoma, and retinal diseases. The impact of these delays on functional visual outcomes and general health rating of elderly patients is not well understood. As part of the Wellness Study, we aimed to investigate the pandemic-related impacts on functional vision and general health rating in an elderly eye patient population in London, Ontario.