Medicine and Health Sciences Commons^™

Roles Of Pgc-1Α/Ppars Pathway In Regulating Insulin Sensitivity In Mouse Skeletal Muscle Cells Under Prolonged Hypoxia, Yunyan Zhang

Electronic Thesis and Dissertation Repository

Using the C₂C₁₂ mouse myoblast cell line, I investigated how prolonged hypoxia affected components of the insulin signalling and FAO/PGC-1α/PPARs pathways, as they might impact insulin sensitivity in skeletal muscle cells.

Hypoxia resulted in lower p-Akt (Thr 308) and higher total cellular GLUT4 protein levels after 7 days of differentiation. This coincided with higher triglyceride content and alterations of the FAO/PGC-1α/PPARs components, both of which could contribute to the changes observed in the components of the insulin signalling pathway. Specifically, cells differentiating in 1% O₂ had lower SIRT1, PPAR- α, FATP4 and MCAD mRNA; accompanied by …

Gender Does Not Influence The Relationship Between Posterior Cruciate Ligament Design And Patient-Reported Outcomes In Patients Receiving Primary Unilateral Total Knee Arthroplasty, Ryan Milan

Electronic Thesis and Dissertation Repository

The effect of the interaction between gender and posterior cruciate ligament (PCL) prosthesis design on patient-reported outcomes is an understudied area of research. We evaluated 1613 patients, from the Ontario Joint Replacement Registry (2001-2006), who underwent primary total knee replacement. This study investigated the impact of the gender-PCL design interaction on Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) change scores and patient satisfaction, by performing linear regression analysis, using full-adjusted models that also included the gender-PCL prosthesis design interaction variable. PCL prosthesis design did not affect WOMAC change scores or satisfaction (p>0.05). Moreover, Gender did not influence either …

Septohippocampal Gabaergic Neurons Mediate The Altered Behaviors Induced By N-Methyl-D-Aspartate Receptor Antagonists., Jingyi Ma, Siew Kian Tai, L Stan Leung

Physiology and Pharmacology Publications

We hypothesize that selective lesion of the septohippocampal GABAergic neurons suppresses the altered behaviors induced by an N-methyl-D-aspartate (NMDA) receptor antagonist, ketamine or MK-801. In addition, we hypothesize that septohippocampal GABAergic neurons generate an atropine-resistant theta rhythm that coexists with an atropine-sensitive theta rhythm in the hippocampus. Infusion of orexin-saporin (ore-SAP) into the medial septal area decreased parvalbumin-immunoreactive (GABAergic) neurons by ~80%, without significantly affecting choline-acetyltransferase-immunoreactive (cholinergic) neurons. The theta rhythm during walking, or the immobility-associated theta induced by pilocarpine, was not different between ore-SAP and sham-lesion rats. Walking theta was, however, more disrupted by atropine sulfate in ore-SAP than …

Resting-State Connectivity Identifies Distinct Functional Networks In Macaque Cingulate Cortex., R Matthew Hutchison, Thilo Womelsdorf, Joseph S Gati, L Stan Leung, Ravi S Menon, Stefan Everling

Physiology and Pharmacology Publications

Subregions of the cingulate cortex represent prominent intersections in the structural networks of the primate brain. The relevance of the cingulate to the structure and dynamics of large-scale networks ultimately requires a link to functional connectivity. Here, we map fine-grained functional connectivity across the complete extent of the macaque (Macaca fascicularis) cingulate cortex and delineate subdivisions pertaining to distinct identifiable networks. In particular, we identified 4 primary networks representing the functional spectrum of the cingulate: somatomotor, attention-orienting, executive, and limbic. The cingulate nodes of these networks originated from separable subfields along the rostral-to-caudal axis and were characterized by positive and …

Methodological Challenges And Clinical Applications Of Hair Cortisol Analysis, Evan W. Russell

Electronic Thesis and Dissertation Repository

This thesis examines methodological and clinical aspects of hair cortisol analysis. The methodological study examines the role of sweat as a contributor to hair cortisol concentrations. Hair cortisol analysis is an effective measure of chronic stress. Cortisol is assumed to enter the hair via blood, sebum, and sweat, however the extent to which sweat contributes to hair cortisol content was unknown. This study concluded that human sweat contains cortisol that likely contributes to hair cortisol content. Subjects with prolonged sweating at the time of hair collection may have increased hair cortisol concentrations that cannot be decreased with conventional laboratory washing …

Vestibular Stimulation Enhances Hippocampal Long-Term Potentiation Via Activation Of Cholinergic Septohippocampal Cells, Leung L. Stan

Physiology and Pharmacology Publications

Vestibular stimulation induced acetylcholine release in the hippocampus, and acetylcholine is known to facilitate long-term potentiation (LTP) in the hippocampus. Thus, we hypothesize that vestibular stimulation enhances LTP in CA1 in freely behaving rats, and this enhancement depends on the activation of septohippocampal cholinergic neurons. Field excitatory postsynaptic potentials were recorded in CA1 area of behaving rats following stimulation of the basal dendritic afferents. LTP was induced by a single stimulation train (100 pulses at 200 Hz) during passive whole-body rotation or during awakeimmobility. LTP induced during rotation was significantly larger than that induced during immobility. Pretreatment with cholinergic antagonist …

Durand Et Al 2012 Supplemental Figures, M. Durand, Svetlana V. Komarova, Ajay Bhargava, Keying Li, Cara Fiorino, Osama Maria, Noushin Nabavi, Morris Manolson, Rene Harrison, S. Jeffrey Dixon, Stephen Sims, Marcin Mizianty, Lukasz Kurgan, Sonia Haroun, Gilles Boire, Maria Lucena-Fernandes, Artur De Brum-Fernandes

Physiology and Pharmacology Publications

Objective. Our objective was to compare the osteoclastogenic capacity of peripheral blood mononuclear cells (PBMCs) from patients with osteoarthritis (OA) to that of PBMCs from self-reported normal individuals.

Methods. PBMCs from 140 patients with OA and 45 healthy donors were assayed for CD14⁺ expression and induced to differentiate into osteoclasts (OCs) over 3 weeks in vitro. We assessed the number of the OCs, their resorptive activity, OC apoptosis, and expression of the following cytokine receptors: receptor activator of nuclear factor κB (RANK), interleukin-1 receptor type I (IL-1R1) and IL-1R2. A ridge logistic regression classifier was developed …

Tracing Notochord-Derived Cells Using A Noto-Cre Mouse: Implications For Intervertebral Disc Development., Matthew R Mccann, Owen J Tamplin, Janet Rossant, Cheryle A Séguin

Physiology and Pharmacology Publications

Back pain related to intervertebral disc degeneration is the most common musculoskeletal problem, with a lifetime prevalence of 82%. The lack of effective treatment for this widespread problem is directly related to our limited understanding of disc development, maintenance and degeneration. The aim of this study was to determine the developmental origins of nucleus pulposus cells within the intervertebral disc using a novel notochord-specific Cre mouse. To trace the fate of notochordal cells within the intervertebral disc, we derived a notochord-specific Cre mouse line by targeting the homeobox gene Noto. Expression of this gene is restricted to the node and …