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Full-Text Articles in Diseases

Spinal Excitability Changes Following Sensory Electrical Stimulation Of The Forearm, Devin K. Box Jun 2021

Spinal Excitability Changes Following Sensory Electrical Stimulation Of The Forearm, Devin K. Box

Electronic Thesis and Dissertation Repository

Sensory electrical stimulation can be used to suppress tremor in Parkinson’s disease. This study investigated the central mechanism underlying this suppression in healthy participants. Reciprocal inhibition (RI) of the wrist flexors before and after a session of sensory electrical stimulation (SES) applied to the antagonistic extensor muscles was assessed using electromyography. It was hypothesized that a 15-minute session of SES, rated by participants as a 3 on a 0-10 pain scale, would produce an increase in RI. Seven of the 18 participants experienced an increase in RI at 0-5 minutes post stimulation, which returned to baseline at 10-15 minutes. The …


The Effects Of Maternal Delta-9-Tetrahydrocannabinol And Cannabidiol Exposure On Fetal Heart Development In Mice, Gregory Robinson Dec 2020

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 …


An Approach For The In-Vivo Characterization Of Brain And Heart Inflammation In Duchenne Muscular Dystrophy, Joanne Tang Sep 2020

An Approach For The In-Vivo Characterization Of Brain And Heart Inflammation In Duchenne Muscular Dystrophy, Joanne Tang

Electronic Thesis and Dissertation Repository

Duchenne muscular dystrophy (DMD) is a neuromuscular disorder caused by dystrophin loss—notably within muscles and CNS neurons. DMD presents as cognitive weakness, progressive skeletal and cardiac muscle degeneration until pre-mature death from cardiac or respiratory failure. Innovative therapies improved life expectancy, but this is accompanied by increased late-onset heart failure and emergent cognitive degeneration. Thus, there is an increasing need to both better understand and track disease pathophysiology in the dystrophic heart and brain prior to onset of severe degenerative symptoms. Chronic inflammation is strongly associated with skeletal and cardiac muscle degeneration, however chronic neuroinflammation’s role is largely unknown in …


The Role Of Regulator Of G Protein Signaling 2 In Inflammatory Cytokine Release In Endotoxemia In Mice, Xin Tong Ma Aug 2020

The Role Of Regulator Of G Protein Signaling 2 In Inflammatory Cytokine Release In Endotoxemia In Mice, Xin Tong Ma

Electronic Thesis and Dissertation Repository

In sepsis, lipopolysaccharide (LPS) activates toll-like receptor 4 to stimulate the release of inflammatory cytokines (e.g. tumor necrosis factor-alpha, TNF-α), leading to cardiac dysfunction. Regulator of G protein signaling 2 (RGS2) limits G protein-coupled receptor signaling by increasing the rate of G protein deactivation or inhibiting G protein-effector interactions. We hypothesized that RGS2 deficiency would enhance proinflammatory responses in endotoxemia. Adult wild-type and RGS2-/- C57BL/6 mice and neonatal cardiomyocytes were treated with LPS and assessed for inflammatory responses and cardiac function. Myocardial TNF-α expression was higher in RGS2-/- mice during endotoxemia. Additionally, cardiac function was impaired in …


Investigating The Role Of Nuclear Receptor Peroxisome Proliferator-Activated Receptor Δ In Obesity-Associated Osteoarthritis, Bethia C. To Mar 2020

Investigating The Role Of Nuclear Receptor Peroxisome Proliferator-Activated Receptor Δ In Obesity-Associated Osteoarthritis, Bethia C. To

Electronic Thesis and Dissertation Repository

Osteoarthritis (OA) is a heterogeneous disease, differentiated based by risk factors that drive joint damage. Peroxisome proliferator-activated receptor delta (PPARd) is a nuclear receptor previously implicated in cartilage damage in OA. Given its deleterious role in post-traumatic OA and in regulating metabolism, we hypothesized that PPARd inhibition will protect against obesity-associated OA. Diet-induced obesity was used to induce OA in mice. Mice fed the western diet for 40 weeks exhibited mild OA, with subchondral bone remodelling occurring alongside cartilage damage. Cartilage-specific Ppard knockout (KO) mice were generated to study its role in metabolic OA. Both wildtype and PPARd KO mice …


Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli Aug 2019

Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli

Electronic Thesis and Dissertation Repository

Elevated plasma lipoprotein(a) (Lp(a)) is the most prevalent heritable risk factor in the development of cardiovascular disease. The apolipoprotein(a) (apo(a)) component of Lp(a) is strongly implicated in the pathogenicity of Lp(a). It is hypothesized that the inflammatory potential of Lp(a)/apo(a) is mediated by the lysine binding ability of the apo(a) kringle IV10 (KIV10) domain, along with its covalently bound oxidized phospholipid (oxPL). Using targeted mutagenesis, two novel null alleles for the LPA gene that generate non-secretable apo(a) species have been identified, resulting from amino acid substitutions in the KIV10 domain. A potential mechanism by which KIV10 oxPL modification is enriched …


Pregestational Diabetes Induced Congenital Heart Defects And Coronary Artery Malformations; Mechanisms And Preventative Therapies, Anish Engineer Jul 2019

Pregestational Diabetes Induced Congenital Heart Defects And Coronary Artery Malformations; Mechanisms And Preventative Therapies, Anish Engineer

Electronic Thesis and Dissertation Repository

Congenital heart defects (CHDs) arise from perturbations in complex molecular and cellular processes underlying normal embryonic heart development. CHDs are the most common congenital malformation, occurring in 1 to 5% of live births, and are the leading cause of pediatric mortality. Adverse genetic and environmental factors can impede normal cardiogenesis and increase the likelihood of CHDs. Pregestational maternal diabetes increases the risk of CHDs in children by more than four-fold. As the prevalence of diabetes rapidly rises among women of childbearing age, there is a need to investigate the mechanisms and potential preventative strategies for these defects. The aim of …


Maternal Nicotine Exposure Induces Congenital Heart Defects In The Offspring Of Mice, Elizabeth Greco Jul 2019

Maternal Nicotine Exposure Induces Congenital Heart Defects In The Offspring Of Mice, Elizabeth Greco

Electronic Thesis and Dissertation Repository

Congenital heart defects are the most prevalent birth defect, and maternal cigarette smoking is a known risk factor. Nicotine replacement therapies are recommended to pregnant women who smoke to aid in smoking cessation, as this alternative is thought to be much safer compared to cigarette smoking. However, these products contain nicotine, and the safety of nicotine on the developing heart is not well known. In this thesis, a mouse model was used to test the hypothesis that maternal nicotine exposure (MNE) during pregnancy leads to congenital heart defects and coronary artery defects in the offspring of mice. MNE resulted in …


The Use Of Current Steering During Subthalamic Deep Brain Stimulation To Alleviate Upper Limb Symptoms Of Parkinson's Disease, Shabna Iftikar Mohideen Nov 2018

The Use Of Current Steering During Subthalamic Deep Brain Stimulation To Alleviate Upper Limb Symptoms Of Parkinson's Disease, Shabna Iftikar Mohideen

Electronic Thesis and Dissertation Repository

Subthalamic (STN) deep brain stimulation (DBS) is an established treatment to alleviate the appendicular motor symptoms of Parkinson's Disease (PD). Current steering during DBS allows the unequal fractionation of current between two electrodes on the lead, resulting in a non-spherical electrical field. It is hypothesized that the way the electrical field is shaped will affect a patient’s upper limb symptom alleviation. Seven PD patients who underwent bilateral STN-DBS were tested over four weeks post-operation. 16 current fractionation settings were tested each week at an amplitude that increased weekly. Optimal setting was defined as the setting that provided the best …


Effects Of Maternal Protein Restriction On The Pulmonary Surfactant System During The Early Life And Adulthood, Reza Khazaee Oct 2018

Effects Of Maternal Protein Restriction On The Pulmonary Surfactant System During The Early Life And Adulthood, Reza Khazaee

Electronic Thesis and Dissertation Repository

Fetal growth restriction (FGR) is defined by low birth weight and contributes to a variety of adult-onset diseases with different severities between males and females. However, the effects of FGR on the pulmonary surfactant are not fully elucidated. In this thesis, first, we investigated the FGR effects on the lung function and the surfactant system at the early postnatal life. It was hypothesized that FGR contributes to alterations of lung mechanics and the surfactant system during the neonatal period. Second, we assessed the FGR effects on the surfactant system in response to sepsis in adulthood. It was hypothesized that FGR …


The Role Of Cholinergic Signaling In Cardiac Function, Rachel Reingold Sep 2018

The Role Of Cholinergic Signaling In Cardiac Function, Rachel Reingold

Electronic Thesis and Dissertation Repository

Cardiovascular disease is one of the leading causes of death in Canada. Treatment currently focuses on preventing the increase of sympathetic signaling seen in heart failure. However, it has recently been noted that cardiac function is dependent on parasympathetic tone. Previous studies have demonstrated the development of heart failure when cholinergic targets are knocked out in cardiomyocytes. Transgenic mouse models that have increased cholinergic transmission show protection against cardiovascular insults. We have shown that transgenic mice overexpressing vesicular acetylcholine transporter in cholinergic cells show cardiovascular protection in response to ex vivo insults. As well, this protection is seen when cholinergic …


Developing Novel Therapeutics For Bacterial Lung Infections, Brandon J. Baer, Ruud Veldhuizen, Cory Yamashita Mar 2018

Developing Novel Therapeutics For Bacterial Lung Infections, Brandon J. Baer, Ruud Veldhuizen, Cory Yamashita

Western Research Forum

Background: Bacterial lung infections are leading causes of death worldwide. Unfortunately, increasing resistance to antibiotics and the inflammation often accompanying these infections are leading to poor outcomes despite antibiotic intervention. Complicating treatment further, the tree-like branching structure of the lung makes drug delivery to distal sites of infection difficult. Our research aims to address these challenges by developing new therapeutics and new tools to improve and assess drug delivery, bacterial killing and inflammation. Our therapy combines host defense peptides, which have been shown to kill antibiotic-resistant bacteria and down regulate inflammation, with a pulmonary vehicle, exogenous surfactant, that can improve …


Functional Changes Associated With Shroom3 Deficiency And Mutation: Implications In Renal Pathophysiology And Disease, Doyun Ko Feb 2018

Functional Changes Associated With Shroom3 Deficiency And Mutation: Implications In Renal Pathophysiology And Disease, Doyun Ko

Electronic Thesis and Dissertation Repository

Chronic kidney disease (CKD) is a substantial global health burden that has recently been linked to the genetic locus SHROOM3 by several genome-wide association studies. Shroom3 is an actin-binding protein that is necessary for inducing apical constriction in epithelial cells. Our lab has previously shown that Shroom3 is critical for proper kidney development and loss of Shroom3 produces symptoms associated with CKD. As hypertension is both a leading cause and comorbidity of CKD, I hypothesized that loss of Shroom3 confers increased susceptibility to hypertension. Using a high-salt induced model of hypertension, I show that Shroom3 deficient mice do not become …


Functional Characteristics Of Four Novel Lone Atrial Fibrillation-Linked Connexin40 Mutants, Mahmoud Noureldin Jul 2017

Functional Characteristics Of Four Novel Lone Atrial Fibrillation-Linked Connexin40 Mutants, Mahmoud Noureldin

Electronic Thesis and Dissertation Repository

Atrial fibrillation (AF) is the most common form of cardiac arrhythmia. Recently, four novel heterozygous Cx40 mutations, K107R, L223M, Q236H, and I257L were identified in 4 of 310 unrelated AF patients. To study possible alterations associated with these mutants, we studied their localization and function using gap junction (GJ)-deficient model cells. Cell pairs expressing Q236H alone or together with wildtype Cx43 showed a significantly lower coupling conductance. Impaired GJ function and dominant negative action on Cx43 of this mutant are consistent with previous findings on the majority of AF-linked Cx40 mutants. The remaining three novel AF-linked mutants did not show …


The Effect Of Insulin Treatment And Exercise Modality On Skeletal Muscle Fiber Size In Streptozotocin-Induced Type 1 Diabetic Rats, John Z. Nickels Jun 2017

The Effect Of Insulin Treatment And Exercise Modality On Skeletal Muscle Fiber Size In Streptozotocin-Induced Type 1 Diabetic Rats, John Z. Nickels

Electronic Thesis and Dissertation Repository

Severe Type 1 Diabetes Mellitus (T1DM) is known to have several negative effects on skeletal muscle mass, a condition known as diabetic myopathy. One of these effects is the atrophy of the glycolytic muscle fibers. However, the role of intensity of insulin treatment and exercise modality in attenuating this loss in fiber cross-sectional area (CSA) specifically has yet to be determined. The purpose of this investigation was to determine the effects of 12 weeks of differing intensity of insulin therapy and exercise modality on the CSA of plantaris muscle fibers, identified by myosin heavy chain (MHC) of STZ-induced T1DM rats. …


Pulmonary Surfactant Fortified With Cath-2 As A Novel Therapy For Bacterial Pneumonia, Brandon J. Baer Mar 2017

Pulmonary Surfactant Fortified With Cath-2 As A Novel Therapy For Bacterial Pneumonia, Brandon J. Baer

Western Research Forum

Background: Bacterial pneumonia is a leading cause of death worldwide, with high mortality rates persisting even after antibiotic treatment. Current treatments for pneumonia involve administration of antibiotics, however after the bacteria are killed they release toxic substances that induce inflammation and lung dysfunction. Host defense peptides represent a potential solution to this problem through their ability to down regulate inflammation. However, effective delivery to the lung is difficult because of the complex branching structure of the airways. My study addresses this delivery problem by using exogenous surfactant, a pulmonary delivery vehicle capable of improving spreading of these peptides throughout the …


Non-Invasive Determination Of Pre-Clinical Markers Of Cardiovascular Diseases In Low Birth Weight And Maternal Western Diet Guinea Pig Offspring Exposed To A Postnatal Western Diet, Jacky Chiu Aug 2015

Non-Invasive Determination Of Pre-Clinical Markers Of Cardiovascular Diseases In Low Birth Weight And Maternal Western Diet Guinea Pig Offspring Exposed To A Postnatal Western Diet, Jacky Chiu

Electronic Thesis and Dissertation Repository

Low birth weight (LBW), and maternal Western Diet (WD) consumption have both been independently implicated to increase the risk of developing cardiovascular diseases (CVDs) in later life. These fetal programmed risks are also believed to exacerbate the effects of a postnatal WD pattern. Therefore, resulting in the development of pre-clinical markers of CVDs, such as insulin resistance (IR), coronary circulation disruptions. This thesis aimed to elucidate the roles of sub-optimal in utero growth through placental insufficiency, or chronic maternal WD consumption, and postnatal WD consumption on the long-term programming of CVDs in a guinea pig model. Early pre-clinical markers of …


Prenatal Programming Of Hepatic Glucose And Cholesterol Regulation In Male Rat Offspring By Chronic Intermittent Hypoxia, Waseem Iqbal Dec 2013

Prenatal Programming Of Hepatic Glucose And Cholesterol Regulation In Male Rat Offspring By Chronic Intermittent Hypoxia, Waseem Iqbal

Electronic Thesis and Dissertation Repository

Obstructive sleep apnea (OSA) is a chronic disorder involving repetitive interruptions in breathing during sleep. Sufferers of OSA are exposed to chronic intermittent hypoxia (CIH), characterized by cyclical reductions in oxygen availability. A number of studies have established a link between OSA and various cardiovascular and metabolic comorbidities in adulthood, including hypertension, obesity, and type II diabetes. While the consequences of OSA in adults have been well described, the cross-generational impact of this condition and potential effects on fetal development are not known. Epidemiological and animal studies have demonstrated that physiological insults during pregnancy lead to diminished growth of offspring …


Elongation Factor 1a-1 And Hepatocyte Response To Fatty Acid Excess, Alexandra M. Stoianov Apr 2013

Elongation Factor 1a-1 And Hepatocyte Response To Fatty Acid Excess, Alexandra M. Stoianov

Electronic Thesis and Dissertation Repository

Obesity is associated with elevated levels of serum fatty acids, which accumulate in nonadipose tissues including the liver. Elongation factor 1A-1 (EF1A-1) has previously been shown to participate in the cell stress and death response of cardiomyocytes to excess saturated fatty exposure, and in steatotic mouse myocardium. In this thesis, the hypothesis that the hepatocyte response to fatty acid overload involves EF1A-1 was tested. EF1A-1 expression was induced in the livers of obese mice in association with severe hepatic steatosis, and in HepG2 human hepatoma cells in response to excess palmitate. Partial translocation of EF1A-1 from the ER to polymerized …