327 research outputs found

    Role of endothelin in the pathogenesis of acute laminitis in horses

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    Acute laminitis is a severely debilitating disease of the laminae of the equine digit; however, the mechanism(s) of pathogenesis have yet to be fully elucidated. In physiologic states, the endothelium synthesizes substances, such as nitric oxide (NO; vasodilator) and endothelin-1 (ET-1; profound vasoconstrictor), which play a crucial role in vasomotor regulation. The overall hypothesis is that the initiating factor in the onset of acute laminitis is a disruption in the balance between NO and ET-1, which leads to digital vasoconstriction and subsequent laminar ischemic necrosis. In vitro studies with digital vessels from healthy horses and horses with naturally-acquired laminitis determined that ET-1 caused concentration-dependent, sustained contraction of arteries and more profound contraction of veins, and incubation with the nonselective ET receptor antagonist (PD145065) at a 10-5 M concentration abolished these contractile effects. ET-1 was then administered into the digit of healthy conscious horses, which resulted in reduced blood flow and the ET antagonist, especially in combination with a NO donor, reversed these reductions. Naturally-acquired laminitic horses had a trend for increased jugular and cephalic venous plasma ET-like immunoreactivity, and horses during the development of black walnut extract (BWE)-induced laminitis developed increased digital venous plasma ET-like immunoreactivity. After validation for equine tissues, ET-1 immunohistochemical staining was conducted on digital vascular and laminar tissues, but no notable differences were found between healthy and naturally-acquired or experimentally-induced laminitic horses. During the developmental stages of BWE-induced laminitis, digital blood flow initially decreased followed by hyperemia, corresponding with demonstration of clinical signs of laminitis. Administration of the ET antagonist, and the antagonist combined with a NO donor, improved Starling force alterations by improving digital vascular resistances and blood flow. Utilizing digital vessel rings from BWE-treated horses, ET-1 caused a concentration-dependent contraction in vitro that was abolished by the ET antagonist. Endothelium-dependent vasodilation was decreased in these vessels, demonstrating possible altered endothelial function due to BWE administration. Based on the results of these studies, ET-1 appears to play a role in the pathophysiology of acute laminitis in horses and continued investigations evaluating ET antagonists as preventative and therapeutic agents for this devastating disease are warranted

    Engage the Future: The New Extension Learners

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    Extension has the opportunity to establish itself as a leader in meeting the changing needs of a new generation of learners. With more than a century\u27s experience in developing and delivering successful programs in communities, Extension can equally succeed in leading the land-grant university system in expanding involvement in five critical areas of education today: degree completion and learner success, community and economic development, engagement of underserved populations, engagement of the newest members of the workforce, and promotion of experiential learning. This commentary identifies and reflects the collective views of 26 administrators who participated in an event designed to vision Extension\u27s expanding role in the 21st century

    The CMB in exact inhomogeneous cosmologies

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    In the past, the standard method of analysing temperature and polarization anisotropies imprinted into the Cosmic Microwave Background by large-scale structure was to use approximate perturbative techniques applied to a Friedmann-Robertson-Walker model. Instead, this thesis researches models based on exact inhomogeneous solutions of the Einstein field equations, such as the Lematre-Tolman (spherically symmetric with dust source) and Szekeres models (non-symmetric), to see whether there might be effects arising from large inhomogeneities that are missed in the standard approach.

    Effect of diet or diet plus physical activity versus usual care on inflammatory markers in patients with newly diagnosed type 2 diabetes: The Early ACTivity in Diabetes (ACTID) randomized, controlled trial

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    This is the final version. Available on open access from Wiley via the DOI in this recordBACKGROUND: Inflammation plays a major role in diabetes-associated cardiovascular disease (CVD). There is uncertainty whether diet and physical activity interventions can be successfully integrated into healthcare settings and reduce markers of inflammation and risk of CVD in patients with type 2 diabetes (T2D). METHODS AND RESULTS: Systemic markers of inflammation were determined in a 12-month, real-world, multicenter, randomized, controlled trial that investigated the effect of diet, diet plus physical activity, and usual care in 593 individuals with newly diagnosed T2D. During the first 6 months, serum C-reactive protein (CRP) improved by -21 (-36 to -1.4)% and -22 (-38 to -3.1)% in diet and diet plus physical activity arms versus usual care. There were also improvements in adiponectin and soluble intercellular adhesion molecule-1 (sICAM-1). Though medication-adjusted CRP was improved between 6 and 12 months for usual care, both interventions were more successful in reducing the relative risk of a high-risk CRP level of >3 mg/L (risk ratios of 0.72 [0.55 to 0.95] for diet versus usual care and 0.67 [0.50 to 0.90] for diet plus activity versus usual care). Furthermore, sICAM-1 (a marker of vascular risk), remained substantially lower than usual care in both intervention arms at 12 months. CONCLUSIONS: Motivational, unsupervised diet and/or diet plus physical activity interventions given soon after diagnosis in real-world healthcare settings improve markers of inflammation and cardiovascular risk in patients with T2D, even after accounting for the effect of adjustments to medication to try and control blood pressure, glycated hemoglobin, and lipids. CLINICAL TRIAL REGISTRATION URL: http://www.controlled-trials.com/. Unique identifier: ISRCTN92162869.British Heart FoundationDiabetes UKUK Department of Healt

    Adrenal insufficiency in acute oral opiate therapy

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    UNLABELLED: Opiate drugs such as morphine are in extensive use for pain relief and palliation. It is well established that these drugs can cause changes in endocrine function, but such effects are not always sufficiently appreciated in clinical practice, especially in relation to the hypothalamic-pituitary-adrenal (HPA) axis. Herein, we report on an 18-year-old man who was diagnosed with a slipped left femoral epiphysis following a long history of pain in his leg. On examination, he was thought to look relatively young for his age and therefore the orthopaedic surgeons arranged an endocrine assessment, which showed an undetectable concentration of serum cortisol and a suppressed concentration of testosterone; therefore, he was referred urgently with a diagnosis of hypopituitarism. We elicited a history that he had been treated with opiate analgesics for 3 days at the time of his original blood tests. Full endocrine assessment including a short Synacthen test revealed that he now had normal adrenal and pituitary function. We conclude that his morphine therapy had caused profound suppression of his HPA and pituitary-gonadal axes and suggest that clinicians should be aware of these significant changes in patients on even short-term opiate therapy. LEARNING POINTS: Therapy with opiates is the standard therapy for severe acute and chronic pain.Such drugs cause profound changes in endocrine function.Importantly, opiates suppress the HPA axis at a central level.Short-term therapy with morphine could be the cause of biochemical adrenocortical insufficiency.Morphine and related drugs also suppress the pituitary-gonadal axis.After discontinuation of therapy with such drugs, adrenal function improves

    Adapting federated cyberinfrastructure for shared data collection facilities in structural biology

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    It has been difficult, historically, to manage and maintain early-stage experimental data collected by structural biologists in synchrotron facilities. This work describes a prototype system that adapts existing federated cyberinfrastructure technology and techniques to manage collected data at synchrotrons and to facilitate the efficient and secure transfer of data to the owner’s home institution

    Structural connectivity and brain network analyses in Parkinson's disease: A cross-sectional and longitudinal study.

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    IntroductionParkinson's disease (PD) is an idiopathic disease of the central nervous system characterized by both motor and non-motor symptoms. It is the second most common neurodegenerative disease. Magnetic resonance imaging (MRI) can reveal underlying brain changes associated with PD.ObjectiveIn this study, structural connectivity and white matter networks were analyzed by diffusion MRI and graph theory in a cohort of patients with PD and a cohort of healthy controls (HC) obtained from the Parkinson's Progression Markers Initiative (PPMI) database in a cross-sectional analysis. Furthermore, we investigated longitudinal changes in the PD cohort over 36 months.ResultCompared with the control group, participants with PD showed lower structural connectivity in several brain areas, including the corpus callosum, fornix, and uncinate fasciculus, which were also confirmed by a large effect-size. Additionally, altered connectivity between baseline and after 36 months was found in different network paths inside the white matter with a medium effect-size. Network analysis showed trends toward lower network density in PD compared with HC at baseline and after 36 months, though not significant after correction. Significant differences were observed in nodal degree and strength in several nodes.ConclusionIn conclusion, altered structural and network metrics in several brain regions, such as corpus callosum, fornix, and cingulum were found in PD, compared to HC. We also report altered connectivity in the PD group after 36 months, reflecting the impact of both PD pathology and aging processes. These results indicate that structural and network metrics might yield insight into network reorganization that occurs in PD
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