Medicine and Health Sciences Commons^™

Measures Of Acoustic Reflexes In Typically Developing Children And Children With Suspected Auditory Processing Disorder, Udit Saxena

Electronic Thesis and Dissertation Repository

A series of studies were conducted to examine the acoustic reflex in normal hearing adults, typically developing children and children with suspected auditory processing disorder (APD). Elevated acoustic reflex thresholds (ART) and shallower acoustic reflex growth functions (ARGF) were found in children with suspected APD in comparison to typically developing children and normal hearing adults. These effects were strongest in the crossed condition. There were no group differences for acoustic reflex latency (ARL) or acoustic reflex decay (ARD).

In all studies the children with suspected APD were divided into two groups based on the diagnosis made on the basis of …

The Impact Of Financial Incentives For Cervical Cancer Screening In Ontario's Primary Care Delivery Models, Ciara Pendrith

Electronic Thesis and Dissertation Repository

Physicians practicing in capitation-based Family Health Organizations and fee-for-service-based Family Health Groups receive bonuses for delivering preventive care, including cervical cancer screening, while those practicing in the traditional fee-for-service model do not. Financial incentives were introduced to increase Ontario’s cervical screening rate to 85%. To date, the impact of incentives for cervical screening on screening rate and cost-effectiveness have not been assessed. Patient-level data obtained from the Institute for Clinical Evaluative Sciences were used to estimate primary care model screening rates and cancer treatment costs. A microsimulation model was developed from published cervical cancer natural history models and parameterized using …

Metabolic Correlates In Spinal Cord Compression Measured By Magnetic Resonance Spectroscopy In The Motor And Sensory Cortices, Sandy Goncalves

Electronic Thesis and Dissertation Repository

Surgical outcome for patients suffering from cervical myelopathy (CM) is unpredictable with varying motor and sensory symptom recovery. Previous in-vivo magnetic resonance spectroscopy (MRS) studies of patients surgically treated for CM have demonstrated decreased N-acetylaspartate (NAA)/creatine levels in the motor cortex indicating reduced neuronal function. The goal of this thesis was to determine whether absolute NAA changes in the motor and sensory cortices mirror the pattern of motor and sensory functional change observed in patients post surgical treatment.

MRS data were acquired on a 3.0 Tesla Siemens MRI along with clinical outcome measures at baseline, 6-weeks and 6-months post-surgery. …

A Phenomenological Study Of Prescription Drug Abuse Among Children And Youth, Eric A. Collins

Electronic Thesis and Dissertation Repository

Prescription drugs ranked as the third highest substance used/abused among Canadian youth (Health Canada, 2014). This research is a retrospective phenomenological study on child and youth prescription drug abuse. Currently, there is a lack of qualitative research in this area. The primary goal of this study is to understand the lived experiences of child and youth prescription drug abuse in order to provide greater depth and breadth into the complexities of this behaviour. Based on the aim of this study, I developed the following research question: what are the lived experiences of prescription drug abuse during childhood and adolescence? Six …

Response Of Soil Nitrification To The Veterinary Pharmaceuticals Monensin, Ivermectin And Zinc Bacitracin, Magda A. Konopka

Electronic Thesis and Dissertation Repository

Pharmaceutical residues can reach agricultural land through amendment with animal or human waste. Since 2010, a series of replicated plots received annual applications of ivermectin, monensin and zinc bacitracin, either singly or in a mixture, at 0.1 mg/kg and 10 mg/kg concentrations. I collected soil samples before and after the fourth annual application of pharmaceuticals and assayed them for functional changes and amoA gene abundance, a gene needed for ammonia oxidation. In 2013, I exposed the soils to 100 mg/kg in a laboratory experiment which resulted in acceleration of nitrification. Under 10 mg/kg treatments in the field the abundance of …

Modulation Of The Cardiomyocyte Hypertrophic Responses To Endothelin-1 By Adipocytes, Suresh Chandra Bairwa

Electronic Thesis and Dissertation Repository

Leptin and adiponectin are the adipokines that are shown to exert pro-hypertrophic and anti-hypertrophic effects respectively, in cardiomyocytes. We sought to determine the direct interaction between the adipocytes and cardiomyocytes during endothelin-1 (ET-1)-induced cardiomyocyte hypertrophy and determine the role of leptin and adiponectin.

The adipose tissue conditioned medium (ACM) inhibited the ET-1-induced hypertrophy in a concentration-dependent manner and this anti-hypertrophic effect was more potent or reversed in the presence of leptin receptor antagonist (LRA; 0.1 nM) or adiponectin receptor-1 antibody (ARA; 100 ng/mL), respectively. ACM from heart failure rats induced by coronary artery ligation or obese rats did not mitigate …

Assessing The Structural Validity Of The Measure Of Processes Of Care (Mpoc-20) In Children With Epilepsy, Kariym Christopher Joachim

Electronic Thesis and Dissertation Repository

The goal of this thesis was to determine whether the 20-item Measure of Processes of Care (MPOC-20) questionnaire remains structurally/factorially valid among children with epilepsy, and to propose adaptations if it did not. Establishing the MPOC-20’s structural validity in this population makes it possible to draw conclusions on the potential effects of parent-perceived Family-Centred Care (FCC) on health outcomes within this population. Data came from the Health-related Quality of Life for Children with Epilepsy Study (HERQULES). Confirmatory Factor Analysis (CFA) indicated that the original five factor model fit poorly in children with epilepsy. An exploratory analysis within a CFA framework …

The Lunches Study: Elementary School Children's Packed Lunch Contents And Intake In The Traditional Vs. Balanced School Day Schedule, Lisa Neilson

Electronic Thesis and Dissertation Repository

The Balanced School Day (BSD), an alternative to the Traditional Schedule (TS), provides two 20-minute eating periods during the school day, rather than a midday lunch break. Widespread implementation of the BSD schedule has occurred across Ontario with limited systematic evaluation of potential health outcomes. The purpose of this study was to compare the food and nutrient value of grade 3 and 4 students’ packed lunch contents and consumption in the BSD versus TS, by direct observation. When compared to the TS, more BSD students had a sugar-sweetened beverage packed in their lunch. Greater portions of snack items were also …

Effects Of Reduced Muscular Strength On Running Kinematics Relating To The Planus Foot, Adam D. Froats

Electronic Thesis and Dissertation Repository

The potential for injury is present in all forms of physical activity, particularly events involving repetitive motion. In attempt to identify kinematic changes following running induced reductions in muscular strength, 15 participants completed recorded treadmill runs before and after an outdoor run. Kinematics were recorded using a Vicon motion capture system and processed using 3D GAIT custom software. Using repeated measures ANCOVA with side (dominant and non-dominant) and time (pre-run and post-run) as within subject factors, and strength and arch height as covariates, no statistically significant differences were obtained. Using Pearson’s product-moment correlation coefficients to compare successive strides, post-run reductions …

Mouse Models Of Intervertebral Disc Development, Degeneration And Mechanical Loading, Matthew R. Mccann

Electronic Thesis and Dissertation Repository

Intervertebral disc (IVD) degeneration is a complex and multi-factorial process that is influenced by aging, genetic predispositions and environmental influences, such as altered mechanical loading. While recent studies have begun to characterize changes in the IVD associated with degeneration, the underlying etiology remains elusive. It is thought that the loss of notochord cells from the nucleus pulposus (NP) is one initiating factor contributing to the cascade of disc degeneration. However, questions remain about the function of notochord cells within the disc, including their capacity as tissue specific progenitor cells for the nucleus pulposus. We have demonstrated, with the use of …

A Comparison Of Clinical Trial And Model-Based Cost Estimates In Glaucoma – The Case Of Repeat Laser Trabeculoplasty In Ontario, Omar Akhtar

Electronic Thesis and Dissertation Repository

Background and objective: For cost-effectiveness analyses (CEA) of glaucoma interventions to be of use they require valid and accurate cost and effectiveness data. Costs remain understudied relative to effectiveness. The impact of cost estimation methods on resultant estimates is unknown in glaucoma. Direct measurement of costs is labour-intensive and expensive. Decision-analytic modelling of costs using literature sources, expert opinion, institutional experience and assumptions provides a quicker, less laborious alternative to empirical costing. A lack of long-term effectiveness data in chronic diseases like glaucoma means that modelling is widespread and inevitable, both for CEAs and budget impact projections. The same problem …

Prostate Cancer Microparticles As A Next Generation Screening Tool For Prostate Cancer, Khurram M. Siddiqui

Electronic Thesis and Dissertation Repository

Currently available screening tests for prostate cancer (PCa) are neither very sensitive nor specific. Microparticles (MP) are submicron tumor cell fragments released by PCa cells into the circulation and offer a possible means of sampling the tumor. We evaluated the utility of a MP blood test using nanoscale flow cytometry to distinguish patients with PCa from patients with benign prostatic hyperplasia (BPH). We used monoclonal antibodies against prostate specific membrane antigen, gastrin releasing peptide receptor and ghrelin peptide ligand.

We found higher but statistically insignificant, PSMA and Ghrelin dual +ve MP counts in the BPH group. Our results show that …

An Examination Of Psychological Variables Influencing Perceptions Of The Self Among A Sample Of Female Exercise Initiates, Lisa Cooke

Electronic Thesis and Dissertation Repository

The general purpose of this dissertation was to explore the relationship among and within cognitive variables associated with exercise initiation and maintenance in a sample of female exercise initiates.

Manuscript 1 was structured to explore the changes to exercise identity among a population of female exercise initiates (N = 78) grouped into an imagery or control condition. Previous research has found that a strong exercise identity is associated with more frequent exercise (Strachan et al., 2009) and increases over time as a person continues to exercise (Cardinal & Cardinal, 1997). Participants were assessed multiple times (weeks 0, 5, 9, …

The Relationship Of Plantar Sensation With Standing Balance And Gait Post-Stroke, Stephen Parsons

Electronic Thesis and Dissertation Repository

Gait and balance dysfunction after stroke limit independence and quality of life. Numerous contributing factors have been investigated but the role of sensation deficits has received little attention. This thesis investigated the relationship between plantar cutaneous sensation and 1) standing balance, 2) gait, and 3) use of vision to compensate for sensory loss with a secondary analysis of data from individuals with subacute stroke. Associations between standing balance, gait and sensation were investigated with Spearman correlations. Individuals classified as impaired or intact sensation were compared on gait and standing balance measures. This thesis found plantar sensation is related to standing …

Poly(Ester Amide) And Poly(Ethyl Glyoxylate) Nanoparticles For Controlled Drug Release, Amira Mohamed Moustafa

Electronic Thesis and Dissertation Repository

The objective of this research was to develop polymeric nanoparticles (NPs) having improved drug release properties for drug delivery. Poly(ester amide)s (PEAs) are promising biodegradable polymers. PEA NPs were prepared via emulsification-evaporation and salting-out methods and optimized through by varying different processing parameters. Polymer-model drug conjugates based on PEAs containing L-aspartic acid and rhodamine B were synthesized and used for NP preparation. Release behavior was studied and compared to a control system with physically encapsulated rhodamine B. It was shown that the release of rhodamine B from the covalent system did not show the burst effect and exhibited a slower …

Motivational Interviewing Via Co-Active Life Coaching Intervention For Women Seeking A More Physically Active Lifestyle, Andrea M. Goddard

Electronic Thesis and Dissertation Repository

The purpose of this 12-week pre-post design pilot study was to assess the impact of Motivational Interviewing via Co-Active Life Coaching (MI-via-CALC) on exercise-specific self-efficacy, barrier-specific self-efficacy, self-esteem, and 12-week study duration engagement in physical activity (PA) for 25 women between the ages of 30 and 55 years. Participants were assessed quantitatively using the previously validated McAuley Exercise-Specific Self-Efficacy Scale (EXSE), McAuley Barrier-Specific Self-Efficacy Scale (BARSE), Rosenberg Self-Esteem Scale (RSES), and International Physical Activity Questionnaire (IPAQ-SF) at pre-, mid-, and post-intervention. Four one-way repeated measures ANOVAs were completed for each scale, and statistically significant differences in barrier-specific self-efficacy were detected …

Environmental Health Effects Of Multiple Exposures: Systemic Risks And The Detroit River International Crossing Study, Tor H. Oiamo

Electronic Thesis and Dissertation Repository

This thesis examines cumulative exposures to traffic noise and outdoor air pollution on environmental and health related quality of life in Windsor, Ontario, and provides a critical analysis of the environmental assessment process for the Detroit River International Crossing (DRIC) Study. The research utilizes a systemic risk framework to understand environmental health and stress effects of cumulative exposures. The significance of this research is based on a relative absence of literature on the systemic health risks of cumulative exposures and the need to elucidate environmental annoyance as a health outcome for risk assessment. The objectives of the research were to …

Regulation Of Crfr1 And 5-Ht2ar By Pdz Domain-Containing Proteins Sap97 And Psd-95, Henry A. Dunn

Electronic Thesis and Dissertation Repository

Previous studies identified a crosstalk mechanism whereby CRFR1 sensitized 5-HT_2AR-mediated signaling via interactions with PDZ domain-containing proteins: a mechanism that may underlie stress-induced anxiety and depression. This prompted an investigation into uncovering which PDZ domain-containing proteins could regulate the crosstalk between these two receptors, and how they could be regulated individually. In the current studies, a subset of PDZ domain-containing proteins were identified that may interact with CRFR1 and 5-HT_2AR. The focus narrowed to two candidates previously implicated in psychiatric disease: SAP97 and PSD-95. We confirmed SAP97 and PSD-95 as interacting partners of CRFR1 in adult …

Rural Heterosexual Female Adolescents' Decision-Making About Sexual Intercourse And Pregnancy In Ontario, Paulina Ezer

Electronic Thesis and Dissertation Repository

Rural areas in Ontario tend to have higher rates of adolescent pregnancy. A constructivist grounded theory methodology was used to gain an in-depth understanding of rural female adolescents’ decision-making process regarding sexual intercourse and their reproductive health, and how they view rural factors and circumstances influencing this process. The adolescent sexual decision-making process that emerged from the analysis involved prioritizing four influences that affect and are affected by the rural context: personal values and circumstances, family values and expectations, friends’ influences, and community influences. Findings will improve our understanding of how rural female adolescents make choices regarding their reproductive health. …

Are Patients At The Centre Of Care?: A Qualitative Exploration Of Myotonic Dystrophy Type 1 (Dm1), Kori A. Ladonna

Electronic Thesis and Dissertation Repository

Health care for individuals living with myotonic dystrophy (DM1)—an uncommon, life-limiting neurological condition for which there are few treatments—may be challenged by patients’ symptoms including cognitive and behavioral impairments. Is patient-centered care—which incorporates the values, experiences and expertise of patients and their caregivers—feasible or achievable? Uncovering patients’ and their caregivers’ experiences of living with DM1, their health care expectations, and their health care providers’ (HCP) perspectives about care is essential for examining patient-centered care in this population. Therefore, the purpose of this research is to: (1) add patients’ and caregivers’ voices to the literature, (2) explore on-going care provision for …

Investigating Cortical Changes In Cervical Spondylotic Myelopathy Using Functional Magnetic Resonance Imaging, Proton Magnetic Resonance Spectroscopy And Diffusion Tensor Imaging, Izabela Kowalczyk

Electronic Thesis and Dissertation Repository

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in older adults. CSM can present abruptly with severe symptoms of neurological impairment or insidiously with a slow stepwise deterioration. There is no current imaging modality or biomarker that can help predict which patient will successfully respond to conservative versus surgical treatment. The goal of this thesis was to follow CSM patients longitudinally to assess how brain function, metabolism, and structure correlate to clinical outcomes in the context of recovering neurological function following surgery.

Chapter 1 of this thesis will provide a detailed literature review of the …

Navigating Life With Hiv: The Lived Experiences Of Youth Living With Hiv, Tamara M M Landry

Electronic Thesis and Dissertation Repository

Youth and young adults living with HIV, between the ages of 15 and 29 represent one-quarter of the new infection rates in Canada, but little is known about the safer sex practices, HIV disclosure processes and coping mechanisms used by this important but often neglected group to manage the every day realities of living with HIV. The primary objectives of this study were to gather qualitative data about the lived experiences of Canadian youth who are living with HIV and enhance our understanding of their experiences of becoming HIV-positive, navigating issues related to safer sex and HIV disclosure, and managing …

Pancreatic Beta Cell Plasticity And Involvement Of Insulin-Expressing Progenitor Cells, Christine A. Beamish

Electronic Thesis and Dissertation Repository

Islet transplants have been successfully used as treatment for diabetes, but are limited by shortages of cadaveric insulin-producing β-cells. An alternate source may be the dedifferentiation, expansion, and subsequent redifferentiation of pancreatic islets or β-cells using in vitro techniques prior to transplant. Based on protocols which described the dedifferentiation of human islets to ductal-like cells, we hypothesized that neonatal mouse islets could be similarly dedifferentiated in vitro. Dedifferentiation techniques produced significant duct-like cells, but redifferentiation to insulin-expressing cells was limited. RIPCre;Z/AP+/+ mice were consequently utilized to lineage trace β-cell fate during culture by a human placental alkaline phosphatase (HPAP) reporter. …

Influence Of Polycaprolactone And Basic Fibroblast Growth Factor On Gingival Fibroblasts, Sarah Michelsons

Electronic Thesis and Dissertation Repository

Guided tissue regeneration (GTR) to regenerate periodontal tissue involves placement of a cell-occlusive barrier membrane functionally excluding the gingiva and associated oral epithelium from the periodontal defect. Gingival connective tissue (CT) contains a rich vascular plexus and is a source of progenitor cells which could contribute to periodontal regeneration. We propose the use of a novel biodegradable and bioactive electrospun fibrous polycaprolactone (PCL) scaffold loaded with microspheres releasing basic fibroblast growth factor (bFGF) to promote gingival CT growth while maintaining a barrier to the oral epithelium. Scaffolds supported human gingival fibroblast proliferation and mesenchymal cell infiltration in a bFGF dose …

Acquisition And Reconstruction Techniques For Fat Quantification Using Magnetic Resonance Imaging, Abraam S. Soliman

Electronic Thesis and Dissertation Repository

Quantifying the tissue fat concentration is important for several diseases in various organs including liver, heart, skeletal muscle and kidney. Uniquely, MRI can separate the signal from water and fat in-vivo, rendering it the most suitable imaging modality for non-invasive fat quantification. Chemical-shift-encoded MRI is commonly used for quantitative fat measurement due to its unique ability to generate a separate image for water and fat. The tissue fat concentration can be consequently estimated from the two images. However, several confounding factors can hinder the water/fat separation process, leading to incorrect estimation of fat concentration.

The inhomogeneities of the main …

The Effect Of Diffusive And Convective Sodium Balance During Hemodialysis On Interdialytic Weight Gain, Benjamin Thomson

Electronic Thesis and Dissertation Repository

Patients with end stage renal disease (ESRD) often require hemodialysis treatments in which blood’s water and dissolved solutes undergo diffusion and convection by exposure to an extracorporeal membrane. The leading cause of death in this population is cardiovascular, and how hemodialysis is prescribed alters total sodium balance, a critical determinant of cardiovascular health. We performed retrospective and prospective analysis of data from patients in the Southwestern Ontario Regional Hemodialysis Program. An increased Dialysate sodium (Dial-Na+) to Pre-dialysis plasma sodium (Pre- Na+) concentration difference (DPNa+) leads to adverse clinical outcomes in hemodialysis patients. The post- to pre-dialysis plasma sodium difference (PPNa+) …

Towards Stem Cell Treatment For Duchenne Muscular Dystrophy-Related Cardiomyopathy, Bogdan A. Bondoc

Electronic Thesis and Dissertation Repository

Duchenne muscular dystrophy (DMD) is a progressive muscular degenerative disease affecting 1 in 3,500 boys. Cardiomyopathy is observed in 95% of patients aged 18 and older, accounting for 30% of deaths. While innovative treatments have been employed to curb symptoms in skeletal muscle, few show success in the heart, and no cure for DMD exists. Recently, regenerative therapy using cardiac stem cells (CSCs) has shown very promising results, but efficacy in DMD remains undetermined. This dissertation sought to provide preliminary insight into the effects of murine Sca-1⁺ CSC therapy. Three-dimensional echocardiography was validated and used to gauge cardiomyopathy in …

Quality Of Life And Health-Related Quality Of Life In Children With Duchenne Muscular Dystrophy, Yi Wei

Electronic Thesis and Dissertation Repository

Quality of life studies in Duchenne Muscular Dystrophy are scarce. This study explores the relationship between the broad concept of quality of life and the more focused concept of health-related quality of life and examines the relationships between patient and family characteristics and health-related quality of life. Participants were recruited from the Canadian Neuromuscular Disease Registry, 98 parents and 85 children completed the Quality of My Life and Pediatric Quality of Life Inventory questionnaires. Simple regression was used to examine the relationship between quality of life and health-related quality of life. Multivariable linear regressions were used to determine child and …

Gender Relations In Hospice Palliative Home Care For Clients With Cancer And Their Family Caregivers: A Critical Analysis, Nisha S. Sutherland

Electronic Thesis and Dissertation Repository

The purpose of this study was to critically examine gender relations in the sociopolitical context of hospice palliative home care for clients with cancer and their family caregivers. Using a critical feminist lens, I employed critical ethnography as a methodology to uncover taken-for-granted attitudes, beliefs, and practices that shape health and health care experiences within the culture of end-of-life at home. The study addressed the following research questions: (a) How do gender relations shape health and health care experiences within the socio-political context of hospice palliative home care for clients with cancer and their caregivers?; (b) How do gendered processes …

Understanding Women's Health Promotion In Rural Canadian Churches, Robyn Plunkett

Electronic Thesis and Dissertation Repository

Many rural health resources are linked to community churches, which are often well attended, especially by rural women. Thus, the rural church may be an effective health resource for rural Canadian women who have compromised access to health resources. Despite the significant role that the rural church plays in the life of rural communities, there is very limited research that addresses how the church acts or could act as a health resource for rural women. Furthermore, there is limited understanding of how the church as a place may influence health promotion in rural communities. This dissertation explores the relevance of …