88 research outputs found

    Non-Profits and Policy Advocacy: Learning from Success

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    This document is a review of successful non-profit policy advocacy practices. Using case studies and examples from Alberta, Canada, and internationally, this guide outlines how and why non-profits should participate in policy advocacy, and breaks down some of the key features of successful policy advocacy efforts. The appendices contain further policy advocacy resources and contact information for policy advocacy coalitions working on a variety of campaigns

    Differential expression of ADAMTS -1, -4, -5 and TIMP -3 in rat spinal cord at different stages of acute experimental autoimmune encephalomyelitis

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    Experimental autoimmune encephalomyelitis (EAE) is an animal model of inflammatory demyelination, a pathological event common to multiple sclerosis (MS). During CNS inflammation there are alterations in the extracellular matrix (ECM). A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS) -1, -4 and -5 are proteases present in the CNS, which are able to cleave the aggregating chondroitin sulphate proteoglycans, aggrecan, phosphacan, neurocan and brevican. It is therefore important to investigate changes in their expression in different stages of EAE induction. We have investigated expression of ADAMTS-1, -4, -5 and Tissue inhibitor of metalloproteinase (TIMP) -3, by real-time RT-PCR. We have also examined protein expression of ADAMTS-1, -4 and -5 by western blotting and immunocytochemistry in spinal cord from animals at different stages of disease progression. Our study demonstrated a decrease in ADAMTS-4 mRNA and protein expression. TIMP-3 was decreased at the mRNA level although protein levels were increased in diseased animals compared to controls. Our study identifies changes in ADAMTS expression during the course of CNS inflammation which may contribute to ECM degradation and disease progression.</p

    ADAMTS -1 and -4 are up-regulated following transient middle cerebral artery occlusion in the rat and their expression is modulated by TNF in cultured astrocytes

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    ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) enzymes are a recently described group of metalloproteinases. The substrates degraded by ADAMTS-1, -4 and -5 suggests that they play a role in turnover of extracellular matrix in the central nervous system (CNS). ADAMTS-1 is also known to exhibit anti-angiogenic activity. Their main endogenous inhibitor is tissue inhibitor of metalloproteinases (TIMP)-3. The present study was designed to investigate ADAMTS-1, -4 and -5 and TIMP-3 expression after experimental cerebral ischaemia and to examine whether cytokines known to be up-regulated in stroke could alter their expression by astrocytes in vitro. Focal cerebral ischaemia was induced by transient middle cerebral artery occlusion in the rat using the filament method. Our results demonstrate a significant increase in expression of ADAMTS-1 and -4 in the occluded hemisphere but no significant change in TIMP-3. This was accompanied by an increase in mRNA levels for interleukin (IL)-1, IL-1 receptor antagonist (IL-1ra) and tumour necrosis factor (TNF). ADAMTS-4 mRNA and protein was up-regulated by TNF in primary human astrocyte cultures. The increased ADAMTS-1 and -4 in experimental stroke, together with no change in TIMP-3, may promote ECM breakdown after stroke, enabling infiltration of inflammatory cells and contribute to brain injury. In vitro studies suggest that the in vivo modulation of ADAMTS-1 and -4 may be controlled in part by TNF.</p

    Decellularisation and Histological Characterisation of Porcine Peripheral Nerves

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    Peripheral nerve injuries affect a large proportion of the global population, often causing significant morbidity and loss of function. Current treatment strategies include the use of implantable nerve guide conduits (NGC’s) to direct regenerating axons between the proximal and distal ends of the nerve gap. However, NGC’s are limited in their effectiveness at promoting regeneration Current NGCs are not suitable as substrates for supporting either neuronal or Schwann cell growth, as they lack an architecture similar to that of the native extracellular matrix (ECM) of the nerve. The aim of this study was to create an acellular porcine peripheral nerve using a novel decellularisation protocol, in order to eliminate the immunogenic cellular components of the tissue, while preserving the three-dimensional histoarchitecture and ECM components. Porcine peripheral nerve (sciatic branches were decellularised using a low concentration (0.1 %; w/v) sodium dodecyl sulphate in conjunction with hypotonic buffers and protease inhibitors, and then sterilised using 0.1 % (v/v) peracetic acid. Quantitative and qualitative analysis revealed a ≥95 % (w/w) reduction in DNA content as well as preservation of the nerve fascicles and connective tissue. Acellular nerves were shown to have retained key ECM components such as collagen, laminin and fibronectin. Slow strain rate to failure testing demonstrated the biomechanical properties of acellular nerves to be comparable to fresh controls. In conclusion, we report the production of a biocompatible, biomechanically functional acellular scaffold, which may have use in peripheral nerve repair

    In Vivo Gene Knockdown in Rat Dorsal Root Ganglia Mediated by Self-Complementary Adeno-Associated Virus Serotype 5 Following Intrathecal Delivery

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    We report here in adult rat viral vector mediate-gene knockdown in the primary sensory neurons and the associated cellular and behavior consequences. Self-complementary adeno-associated virus serotype 5 (AAV5) was constructed to express green fluorescent protein (GFP) and a small interfering RNA (siRNA) targeting mammalian target of rapamycin (mTOR). The AAV vectors were injected via an intrathecal catheter. We observed profound GFP expression in lumbar DRG neurons beginning at 2-week post-injection. Of those neurons, over 85% were large to medium-diameter and co-labeled with NF200, a marker for myelinated fibers. Western blotting of mTOR revealed an 80% reduction in the lumbar DRGs (L4–L6) of rats treated with the active siRNA vectors compared to the control siRNA vector. Gene knockdown became apparent as early as 7-day post-injection and lasted for at least 5 weeks. Importantly, mTOR knockdown occurred in large (NF200) and small-diameter neurons (nociceptors). The viral administration induced an increase of Iba1 immunoreactivity in the DRGs, which was likely attributed to the expression of GFP but not siRNA. Rats with mTOR knockdown in DRG neurons showed normal general behavior and unaltered responses to noxious stimuli. In conclusion, intrathecal AAV5 is a highly efficient vehicle to deliver siRNA and generate gene knockdown in DRG neurons. This will be valuable for both basic research and clinic intervention of diseases involving primary sensory neurons

    Contrast and Complexity in Chinese Tonal Systems

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    Lexical tone has been investigated from a diverse variety of perspectives, with significant disagreement as to whether a feature-based analysis can account for the synchronic and diachronic patterning of tonal systems. This thesis investigates the tonal systems of 13 Chinese languages from the Yue and Mandarin groups, and presents a feature-based model which accounts for their respective inventories and patterns of phonological alternations, and traces their respective diachronic trajectories back to the feature specification of a reconstructed Middle Chinese tonal inventory. The analysis here employs hierarchically arranged contrastive features. Whereas analyses postulating a universal set of phonetic features tend to incur a number of descriptive and theoretical problems when tasked with the description of tonal systems, utilizing language-specific features grounded in tonal alternations and phonetics sheds significant light on synchronic and diachronic patterning. The reconstruction of a common Middle Chinese proto-language enables the description of a precise phylogenetic tree as well as the postulation of a number of contrastive reanalyses. It is found that both reanalysis and the specific phonetic content of tonal inventories are accounted for by postulating a principle of complexity minimization: the cognitive apparatus chooses representations which minimize the algorithmic entropy or Kolmogorov complexity of phonologies and maximize the reuse of structure. At each point in the diachronic trajectory of a language, speakers choose the phonological representation with the lowest total complexity. Phonetic naturalness can also be formalized as the minimization of complexity, and a general tendency towards an inverse relationship between the naturalness of tonal inventories and the amount of activity in a given language is described. The cognitive preference for the minimization of complexity represents a parsimonious solution to the problem of induction which avoids the stipulation of hard-coded universals pre-specified in the cognitive apparatus.Ph.D

    Gene expression in age-related degeneration of the nervous system

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    Bibliography: p. 130-157

    Matrix metalloproteinases and diseases of the CNS

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    Matrix metalloproteinases (MMPs) are increasingly being implicated in the pathogenesis of several CNS diseases. In multiple sclerosis, MMPs could be responsible for the influx of inflammatory mononuclear cells into the CNS, contribute to myelin destruction and disrupt the integrity of the blood-brain barrier; in Alzheimer's disease, MMPs might mediate the deposition of amyloid beta-proteins; and MMPs are known to contribute to the invasiveness of malignant glioma cells and might regulate their angiogenic capacity. Nonetheless, MMPs could also have beneficial roles in recovery from CNS injury.Therefore, both the identity of the MMP and its cellular origin could determine whether disease pathogenesis or regeneration occurs, and thus synthetic MMP inhibitors might be valuable for treating some CNS diseases
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