Medicine and Health Sciences Commons^™

The Effects Of Maternal Delta-9-Tetrahydrocannabinol And Cannabidiol Exposure On Fetal Heart Development In Mice, Gregory Robinson

Electronic Thesis and Dissertation Repository

Up to 22.6% of pregnant women consume cannabis during pregnancy despite the uncertainty of teratogenicity of the main ingredients in cannabis, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). This study tested the hypothesis that gestational THC and CBD exposure leads to heart abnormalities. Daily, oral THC exposure induced heart abnormalities in 68% of offspring with three main phenotypes including thickened semilunar valves, ventricular myocardial hypertrophy and hypoplastic coronary arteries in fetuses, and postnatal cardiac dysfunction. Altered gene expression of key cardiogenic regulators, increased proliferation, and reduced epicardial epithelial-to-mesenchymal-transition were demonstrated implicating potential mechanisms responsible for these abnormalities. Also, maternal CBD exposure resulted …

Perspectives Of Canadian University Coaches On Integrating Sport Psychology And Mental Performance Consultants In Varsity Programs, Federico Cisneros Sánchez

Electronic Thesis and Dissertation Repository

Recently, sport psychology has become a more popular resource for athletes and coaches when looking to increase performance. It is unknown how many Canadian universities utilize sport psychology services in their athletic programs. Semi-structured interviews were conducted with coaches of Canadian university varsity teams to learn about their opinions on sport psychology and mental performance consultants (MPCs). The research was approached from a pragmatic perspective. Results showed that MPCs are important to enhance performance and provide mental health resources. MPCs provide athletes with personal and leadership development, mental skills training, and mental health support. MPCs can also be a resource …

The Role Of Haptic Expectations In Reaching To Grasp: From Pantomime To Natural Grasps And Back Again, Robert L. Whitwell, Nathan J. Katz, Melvyn A. Goodale, James T. Enns

Brain and Mind Institute Researchers' Publications

© Copyright © 2020 Whitwell, Katz, Goodale and Enns. When we reach to pick up an object, our actions are effortlessly informed by the object’s spatial information, the position of our limbs, stored knowledge of the object’s material properties, and what we want to do with the object. A substantial body of evidence suggests that grasps are under the control of “automatic, unconscious” sensorimotor modules housed in the “dorsal stream” of the posterior parietal cortex. Visual online feedback has a strong effect on the hand’s in-flight grasp aperture. Previous work of ours exploited this effect to show that grasps are …

Regional Integration: Physician Perceptions On Electronic Medical Record Use And Impact In South West Ontario, Sadiq Raji

Electronic Thesis and Dissertation Repository

Regional initiatives in the health care context in Canada are typically organized and administered along geographic boundaries or operational units. Regional integration of Electronic Medical Records (EMR) has been continuing across Canadian provinces in recent years, yet the use and impact of regionally integrated EMRs are not routinely assessed and questions remain about their impact on and use in physicians’ practices. Are stated goals of simplifying connections and sharing of electronic health information collected and managed by many health services providers being met? What are physicians’ perspectives on the use and impact of regionally integrated EMR? In this thesis, I …

Risk Stratification For Treatment Decisions In People At Ultra-High Risk For Psychosis: A Cost-Effectiveness Analysis, Olajumoke Marissa Ologundudu

Electronic Thesis and Dissertation Repository

People with psychotic disorders have long-term negative health outcomes and contribute large health system costs. Intervening among those at ultra-high risk (UHR) for psychosis may prevent or mitigate risk for psychotic disorder; however, it is unclear if we should treat all UHR individuals or only those above a certain risk threshold. The objectives were to systematically review the literature on the cost-effectiveness of UHR programs, and to conduct an economic evaluation of a risk stratification strategy, where treatment decisions are based on the probability of transitioning to psychotic disorder. Our systematic review found that UHR programs are potentially cost-effective. The …

Assessment Of Landing Biomechanics And Rehabilitation After Anterior Cruciate Ligament Reconstruction, Sheila S. Gagnon

Electronic Thesis and Dissertation Repository

Aberrant landing biomechanics increase the risk of anterior cruciate ligament (ACL) injury and are a focus of rehabilitation after ACL reconstruction. The purpose of the present thesis was to develop and evaluate methods of assessing landing mechanics and investigate the effects of different rehabilitation strategies after ACL reconstruction. Three studies were conducted. The first study used a Delphi process to develop the content of a Clinician-Rated Drop Vertical Jump Scale to evaluate jump landing mechanics during rehabilitation after ACL reconstruction. Twenty experts participated in four rounds of questioning, resulting in 92% agreement for knee valgus collapse, lateral trunk lean, insufficient …

Case – 18F-Dcfpyl-Positron Emission Tomography/Computed Tomography (Pet/Ct) Time Of Imaging, Golmehr Sistani, Ur Metser, Glenn S. Bauman, David T. Laidley, Stephen E. Pautler, Katherine A. Zukotynski

Medical Biophysics Publications

No abstract provided.

The Effect Of Pigmentation On Latex And Non-Latex Orthodontic Elastics, Dustin Wilson

Electronic Thesis and Dissertation Repository

Background: Intraoral Elastics have been widely used in Orthodontics for well over 100 years. Changes in material composition, manufacturing and addition of color to elastics has shown to effect force levels over time.

Aim: The purpose of the study was to determine the effect of pigmentation on force levels and their degradation over time in both Latex and Non-Latex orthodontic intraoral elastics.

Materials & Methods: Groups consisted of elastics in Latex from American Orthodontics in both natural and four different colors, American Orthodontics Non-Latex in natural, Ormco Latex in both natural and four different colors, Auradonics Latex in both natural …

Reducing Length Of Stay After Total Hip And Knee Arthroplasty: Assessing Cost-Effectiveness, Caregiver Involvement And Surgical Approach, Bryn O. Zomar

Electronic Thesis and Dissertation Repository

Purpose

The overall purpose of this dissertation was to evaluate factors related to reducing length of stay after total hip and knee arthroplasty (THA and TKA).

Methods

Study 1 was a randomized controlled trial (RCT) to investigate the cost-effectiveness of outpatient THA compared to standard overnight stay. Study 2 was a prospective cohort study to assess patient- and caregiver-related factors and how they may relate to caregiver strain and level of assistance when caring for patients undergoing THA and TKA. Finally, Study 3 was a 2x2 factorial RCT to compare the trajectory of early functional recovery between the medial parapatellar …

Intersectional Social Inequalities And Cognitive Functioning Among Community-Dwelling Older Adults In England: A Decomposition Analysis Of The Mediating Role Of Loneliness, Chantel Walwyn

Electronic Thesis and Dissertation Repository

Normative cognitive decline is an emerging public health issue for older adult populations. It is necessary that we take an intersectional approach to examining heterogeneity in cognitive health outcomes. Using complex longitudinal survey data from the English Longitudinal Study of Ageing (ELSA), multiple linear regression models were used to examine the relationship between intersectional group membership based on age, education, and sex, and change in cognitive functioning domains (memory function, and executive function) over an 8-year period. Three-way decomposition analysis was also used to examine the mediating effect of loneliness on the association between intersectional group membership and the change …

Cortical Thickness Estimation In Individuals With Cerebral Small Vessel Disease, Focal Atrophy, And Chronic Stroke Lesions, Miracle Ozzoude, Joel Ramirez, Pradeep Reddy Raamana, Melissa F. Holmes, Kirstin Walker, Christopher J.M. Scott, Fuqiang Gao, Maged Goubran, Donna Kwan, Maria C. Tartaglia, Derek Beaton, Gustavo Saposnik, Ayman Hassan, Jane Lawrence-Dewar, Dariush Dowlatshahi, Stephen C. Strother, Sean Symons, Robert Bartha, Richard H. Swartz, Sandra E. Black

Medical Biophysics Publications

Background: Regional changes to cortical thickness in individuals with neurodegenerative and cerebrovascular diseases (CVD) can be estimated using specialized neuroimaging software. However, the presence of cerebral small vessel disease, focal atrophy, and cortico-subcortical stroke lesions, pose significant challenges that increase the likelihood of misclassification errors and segmentation failures. Purpose: The main goal of this study was to examine a correction procedure developed for enhancing FreeSurfer’s (FS’s) cortical thickness estimation tool, particularly when applied to the most challenging MRI obtained from participants with chronic stroke and CVD, with varying degrees of neurovascular lesions and brain atrophy. Methods: In 155 CVD participants …

Transcriptional Profiling Of Leukocytes In Critically Ill Covid19 Patients: Implications For Interferon Response And Coagulation, Sean E Gill, Claudia C Dos Santos, David B O'Gorman, David E Carter, Eric K Patterson, Marat Slessarev, Claudio Martin, Mark Daley, Michael R. Miller, Gediminas Cepinskas, Douglas Fraser

Paediatrics Publications

BACKGROUND: COVID19 is caused by the SARS-CoV-2 virus and has been associated with severe inflammation leading to organ dysfunction and mortality. Our aim was to profile the transcriptome in leukocytes from critically ill patients positive for COVID19 compared to those negative for COVID19 to better understand the COVID19-associated host response. For these studies, all patients admitted to our tertiary care intensive care unit (ICU) suspected of being infected with SARS-CoV-2, using standardized hospital screening methodologies, had blood samples collected at the time of admission to the ICU. Transcriptome profiling of leukocytes via ribonucleic acid sequencing (RNAseq) was then performed and …

Transcriptional Profiling Of Leukocytes In Critically Ill Covid19 Patients: Implications For Interferon Response And Coagulation, Sean E Gill, Claudia C Dos Santos, David B O'Gorman, David E Carter, Eric K Patterson, Marat Slessarev, Claudio Martin, Mark Daley, Michael R. Miller, Gediminas Cepinskas, Douglas Fraser

Paediatrics Publications

BACKGROUND: COVID19 is caused by the SARS-CoV-2 virus and has been associated with severe inflammation leading to organ dysfunction and mortality. Our aim was to profile the transcriptome in leukocytes from critically ill patients positive for COVID19 compared to those negative for COVID19 to better understand the COVID19-associated host response. For these studies, all patients admitted to our tertiary care intensive care unit (ICU) suspected of being infected with SARS-CoV-2, using standardized hospital screening methodologies, had blood samples collected at the time of admission to the ICU. Transcriptome profiling of leukocytes via ribonucleic acid sequencing (RNAseq) was then performed and …

A Novel Spatio-Temporal Examination Of Children's Accessibility, Exposure, And Engagement To Parks And Recreation Spaces In Middlesex-London, Ontario, Malcolm K. Little

Electronic Thesis and Dissertation Repository

Children are spending more free time engaged in activities indoors, rather than in outdoor environments such as parks and recreation spaces. Parks and recreation spaces provide amenities that promote physical, cognitive, and social health among children. As it relates to the complexities of children’s living situations, properly measuring children’s levels of interactions with these spaces is poorly understood in geography research.

By examining various attributes of children, this thesis improves on the measurement of children’s levels of interactions with parks and recreation spaces. Research herein utilized household survey data, a high-resolution GIS dataset of environmental factors, and GPS logs from …

Population-Based Studies On Medications And Fall-Related Injury In Older Adults, Yu Ming

Electronic Thesis and Dissertation Repository

Background: Fall-related injuries in older adults result in serious consequences to individuals and health care system, especially with the increasing aging population. The purpose of this study was to (1) describe medication prescription patterns within one year prior to fall-related injuries; (2) identify medication classes prescribed within 30 days prior to the injury that were associated to fall-related injury; and (3) examine the association between fall-related injuries and continuous use or new initiation of most commonly prescribed medications.

Methods: Studies used administrative health care data in Ontario. Study 1 described the frequency of medications prescribed to older adults within one …

Pathway‐Extended Gene Expression Signatures Integrate Novel Biomarkers That Improve Predictions Of Patient Responses To Kinase Inhibitors, Ashis Bagchee‐Clark, Eliseos J. Mucaki, Tyson Whitehead, Peter Rogan

Biochemistry Publications

Cancer chemotherapy responses have been related to multiple pharmacogenetic biomarkers, often for the same drug. This study utilizes machine learning to derive multi‐gene expression signatures that predict individual patient responses to specific tyrosine kinase inhibitors, including erlotinib, gefitinib, sorafenib, sunitinib, lapatinib and imatinib. Support vector machine (SVM) learning was used to train mathematical models that distinguished sensitivity from resistance to these drugs using a novel systems biology‐based approach. This began with expression of genes previously implicated in specific drug responses, then expanded to evaluate genes whose products were related through biochemical pathways and interactions. Optimal pathway‐extended SVMs predicted responses in …

The Role Of Timp3 In Microvascular Endothelial Cell-Extracellular Matrix Interaction And Regulation Of Microvascular Barrier Function, Nidhi Kulkarni

Electronic Thesis and Dissertation Repository

Pulmonary microvascular endothelial cell (PMVEC) interactions with the extracellular matrix (ECM) mediates PMVEC barrier function. Further, data suggests an association between decreased PMVEC-ECM interactions under proinflammatory conditions and PMVEC barrier dysfunction. Tissue inhibitor of metalloproteinases 3 (TIMP3) may also regulate barrier function, as PMVEC from Timp3^-/-mice show increased leak. Studies in the developing lung also showed TIMP3 regulating PMVEC-ECM interactions. Based on this, I hypothesized that TIMP3 maintains PMVEC barrier function by promoting PMVEC-ECM interactions.

Using the XperT-permeability assay, Timp3^-/-PMVEC demonstrated enhanced leak vs. WT PMVEC, particularly under proinflammatory conditions, and this was associated with decreased …

Correlates Of Preventable Emergency Department Visits In Canada: Evidence From The Literature And The Canadian Community Health Survey, Tammy Lau

Electronic Thesis and Dissertation Repository

Emergency department (ED) visits for primary healthcare-treatable conditions are preventable and indicate barriers to primary healthcare. The goal of this thesis was to explore the prevalence and key correlates of preventable ED visits among adults in Canada. Our systematic review found that the prevalence of these visits ranged from 4.3% to 59.1% and were associated with younger age, low education, low income, rural residence, and worse self-rated health. Our analysis of data from the 2015-2016 Canadian Community Health Survey found that 39.9% of adults with a regular healthcare provider considered their last ED visit to be preventable. In addition to …

Detection And Quantification Of Cells Using Magnetic Particle Imaging And Magnetic Microspheres, Kierstin P. Melo

Electronic Thesis and Dissertation Repository

Magnetic particle imaging (MPI) is an emerging imaging modality that specifically detects superparamagnetic iron oxide nanoparticles (SPIOs). Our lab has shown that cell tracking with magnetic resonance imaging (MRI) has very high sensitivity, but low specificity and quantification of iron labeled cells is difficult. MPI cell tracking could overcome these limitations. A Momentum^TM MPI system was installed at Robarts in August 2019 and this is the first project to be completed using MPI. In Chapter 2 a series of in vitro experiments are reported which tested the repeatability and reproducibility of imaging SPIO labeled cell samples. There are no …

Improving Hydrid Pet/Mri Cardiovascular Imaging With Improved Hardware Design And Attenuation Correction Coefficient, Adam Helmy Farag

Electronic Thesis and Dissertation Repository

According to the World Health Organization (WHO) report in 2019, cardiovascular diseases (CVD) cause 52% of all illness-related deaths globally and are considered to be the second most common cause of death in Canada. CVD is also estimated to cost the Canadian economy about $21.2 billion in direct and indirect costs. With these figures, it is vital to develop the most effective and accurate methods and tools to diagnose accurately CVD and their causes. One of the promising tools for accurate diagnostic and therapeutic of CVD is the integrated Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) PET/MRI technology, …

Evidence Of An Antigen Presenting Cell Phenotype In Granular Cell Tumours, Benjamin J W A Rogala

Electronic Thesis and Dissertation Repository

Granular Cell Tumours (GCTs) are rare subepithelial lesions that are believed to develop from Schwann cells and are characterized by large polygonal cells with abundant lysosomes. Pilot studies from our laboratory showing unexpected HLA-DR immunoreactivity in GCTs lead us to hypothesize that GCTs have an antigen presenting cell (APC) phenotype.

To test our hypothesis, we assessed immunoreactivity of GCT lesions to APC phenotype markers, including CD68, HLA-DR, CD163, CD40 and CD11c. In addition, we assessed markers of neural crest cell (NCC) origin S100, SOX10, NSE and GAP43. Samples subjected to these studies included 23 cases of GCTs and 10 cases …

Targeting Cd5 To Enhance Immune T Cell Activation And Function In Treatment Of Solid Tumours, Faizah Alotaibi

Electronic Thesis and Dissertation Repository

CD5 is a member of scavenger receptor cysteine-rich superfamily that is expressed primarily on T cells. It can attenuate T-cell receptor signaling and impair cytotoxic T lymphocyte (CTL) activation and is a therapeutic targetable tumour antigen expressed on leukemic T and B cells. However, the potential therapeutic effect of functionally blocking CD5 to increase T cell anti-tumour activity against tumours (including solid tumours) has not been explored. CD5^- solid tumours in CD5 knockout mice display increased in anti-tumour immunity. Hence, blocking CD5 function may have a potential therapeutic effect by enhancing CTL function. Here, I assessed CD5 levels in …

Trends And Factors Associated With Suicide Deaths In Older Adults, Eada Novilla-Surette

Electronic Thesis and Dissertation Repository

Suicide in older adults is a significant overlooked problem worldwide; particularly in Canada where a national suicide prevention strategy has not yet been established. This population-level study utilized and analyzed linked administrative health care databases (from 2011-2015) that were available at ICES (provincial health care administrative data steward), to build a better understanding of suicide (rate; trends; risks/preventive factors) in older adults living in Ontario, Canada. The findings suggest that suicide remains a persistent cause of death in older adults (with an average annual suicide rate of 0.1 per 1000 people over 5 years; the risks include being male, living …

The Experiences Of Family Medicine Teachers And Family Medicine Residents In Multimorbidity Care And Education, Julie A. Copeland

Electronic Thesis and Dissertation Repository

Aim: This thesis explored the experiences of family medicine preceptors and family medicine residents regarding multimorbidity care and education.

Methods: Two qualitative descriptive studies were conducted using semi structured interviews with family medicine preceptors and focus groups with family medicine residents. Interviews and focus groups were audio-taped and transcribed verbatim. Data analysis was iterative and interpretive in nature and done both independently and as a team.

Findings: Multimorbidity care is predominantly provided by family physicians yet there is little focus on multimorbidity education in the medical education curriculum. Multimorbidity education is informal and experiential in nature. There are both facilitators …

Frailty, Clinical Outcomes, And Cost In Patients Undergoing Trans-Catheter Aortic Valve Implantation (Tavi), Zhe Li

Electronic Thesis and Dissertation Repository

The objective of this doctoral was three-fold: 1) to systematically review frailty measures and prognosis of frail patients undergoing TAVI, 2) to examine the performance of frailty indices in predicting clinical outcomes after TAVI, and 3) to examine the performance of frailty indices in predicting one-year costs of TAVI and high-cost TAVI patients.

For the first objective, we systematically reviewed the literature published in 2006 or later. We found that frailty instruments varied across studies, leading to a wide range of frailty prevalence estimates for TAVI recipients and substantial heterogeneity.

For the second objective, we utilized data from the CorHealth …

The Examination Of Expectations In Day-Surgery Patients And The Development Of A Patient Satisfaction Questionnaire For Day-Surgery Patients, Tishara M. Wijayanayaka

Electronic Thesis and Dissertation Repository

Patient satisfaction has become a growing area of study within health care. Existing hospital- wide satisfaction tools don’t provide the specificity that various departments require to truly get a sense of where they stand in terms of patient satisfaction. Further, many of these tools fail to consider an important component associated with satisfaction, patient expectations. Currently, there is no patient satisfaction tool specific to adult day-surgery patients that has been developed through a careful exploration of patient expectations. In this qualitative study, we conducted a series of semi-structured interviews on patients undergoing outpatient surgery to explore expectations. We performed a …

Kidney Injury Molecule-1 Mediated Phagocytosis And Its Therapeutic Application In Ameliorating Renal Transplant Ischemia Reperfusion Injury, Ji Yun Lee

Electronic Thesis and Dissertation Repository

Renal transplantation is a life-saving procedure for patients with end-stage renal disease. Persistent graft inflammation and fibrosis due to injury from repeated insults - both alloantigen-dependent and -independent - lead to chronic allograft dysfunction and long-term graft loss. Ischemia-reperfusion injury (IRI) to the graft is an inescapable consequence of transplantation and can result in significant delayed graft function (DGF). Tissue damage and graft dysfunction resulting from transplant-associated IRI have been correlated with acute rejection and long-term graft loss. During IRI, dying renal proximal tubular epithelial cells (TECs) release pro-inflammatory mediators, worsening tissue damage and further potentiating injury by initiating an …

Shared Functional Connectivity Between The Dorso-Medial And Dorso-Ventral Streams In Macaques, R. Stefan Greulich, Ramina Adam, Stefan Everling, Hansjörg Scherberger

Brain and Mind Institute Researchers' Publications

© 2020, The Author(s). Manipulation of an object requires us to transport our hand towards the object (reach) and close our digits around that object (grasp). In current models, reach-related information is propagated in the dorso-medial stream from posterior parietal area V6A to medial intraparietal area, dorsal premotor cortex, and primary motor cortex. Grasp-related information is processed in the dorso-ventral stream from the anterior intraparietal area to ventral premotor cortex and the hand area of primary motor cortex. However, recent studies have cast doubt on the validity of this separation in separate processing streams. We investigated in 10 male rhesus …

Neural Responses And Perceptual Sensitivity To Sound Depend On Sound-Level Statistics, Björn Herrmann, Thomas Augereau, Ingrid S. Johnsrude

Brain and Mind Institute Researchers' Publications

© 2020, The Author(s). Sensitivity to sound-level statistics is crucial for optimal perception, but research has focused mostly on neurophysiological recordings, whereas behavioral evidence is sparse. We use electroencephalography (EEG) and behavioral methods to investigate how sound-level statistics affect neural activity and the detection of near-threshold changes in sound amplitude. We presented noise bursts with sound levels drawn from distributions with either a low or a high modal sound level. One participant group listened to the stimulation while EEG was recorded (Experiment I). A second group performed a behavioral amplitude-modulation detection task (Experiment II). Neural activity depended on sound-level statistical …

Modeling An Auditory Stimulated Brain Under Altered States Of Consciousness Using The Generalized Ising Model, Sivayini Kandeepan, Jorge Rudas, Francisco Gomez, Bobby Stojanoski, Sree Ram Valluri, Adrian Mark Owen, Lorina Naci, Emily Sophia Nichols, Andrea Soddu

Brain and Mind Institute Researchers' Publications

Propofol is a short-acting medication that results in decreased levels of consciousness and is used for general anesthesia. Although it is the most commonly used anesthetic in the world, much remains unknown about the mechanisms by which it induces a loss of consciousness. Characterizing anesthesia-induced alterations to brain network activity might provide a powerful framework for understanding the neural mechanisms of unconsciousness. The aim of this work was to model brain activity in healthy brains during various stages of consciousness, as induced by propofol, in the auditory paradigm. We used the generalized Ising model (GIM) to fit the empirical fMRI …