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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Novo método de avaliação da incapacidade articular na artrite experimental: investigação do papel das células da glia / New method for assessing articular disability in experimental arthritis: investigation the role of glial cells

Andreza Urba de Quadros 05 February 2013 (has links)
Um bom modelo experimental deve contar com métodos de avaliação eficazes de seus parâmetros. Esta é uma observação importante quando se faz necessária a avaliação da nocicepção e da incapacitação articular em animais experimentais. O estabelecimento de novos critérios aos testes animais é fundamental para que processos inflamatórios articulares possam continuar sendo estudados, entendidos e resolvidos. Buscando contribuir neste sentido, este trabalho realizou a padronização do teste de incapacitação dinâmico (TID) para avaliação da incapacitação articular em modelos experimentais de artrite. Os resultados obtidos mostram que o TID é sensível na avaliação da incapacitação articular em modelos de artrite induzida por antígeno (AIA) ou por zimosana. Além disso é preditivo para o estudo do efeito farmacológico de drogas que interfiram na incapacitação articular como anti-inflamatórias ou analgésicas. Desde o início da década de 90, quando participação das células da glia na dor foi descrita, diversos trabalhos surgiram mostrando seu papel em diferentes modelos animais. A participação das células da glia espinais na dor e incapacitação em modelos experimentais de artrite e artrite reumatoide têm sido relatada, mas não há descrição desta participação em função do tempo de indução do processo inflamatório articular. Por meio de ferramentas farmacológicas e moleculares, este trabalho mostra que as células da glia, tanto espinais como do gânglio da raiz dorsal estão participando na gênese e manutenção da incapacitação inflamatória articular em modelo de AIA. A participação destas células ocorre por meio da liberação de IL-1? e TNF? em nível medular e pela primeira vez é mostrado que a ativação astrocítica parece preceder a ativação microglial neste modelo. / A good experimental model must rely on effective methods of evaluation of its parameters. This is an important observation when it is necessary to evaluate the articular nociception and disability in experimental animals. Establishing new criteria to test animals is essential for inflammatory joint can continue being studied, understood and resolved. Seeking help in this sense, this work constitutes a test dynamic weight bearing (DWB) standardization for assessment of articular incapacitation in experimental models of arthritis. The results show that the DWB is sensitive in assessing the impairment models articular antigen-induced arthritis (AIA) or zimosana. Furthermore is predictive for studying the pharmacological effects of drugs that interfere with articular incapacitation as antiinflammatory or analgesic. Since the early 90s, when participation of glial cells in pain was described, several studies have emerged showing its role in different animal models. The involvement of glial cells in the spinal pain and disability in experimental models of arthritis and rheumatoid arthritis have been reported, but no description of this contribution versus time of induction of joint inflammation. Through molecular and pharmacological tools, this work shows that the glial cells, both as the spinal dorsal root ganglio are participating in the genesis and maintenance of inflammatory joint incapacitation in AIA model. The participation of these cells occurs through the release of IL-1? and TNF? in the spinal cord and the first time it is shown that astrocytic activation appears to precede the microglial activation in this model.
22

Novo método de avaliação da incapacidade articular na artrite experimental: investigação do papel das células da glia / New method for assessing articular disability in experimental arthritis: investigation the role of glial cells

Quadros, Andreza Urba de 05 February 2013 (has links)
Um bom modelo experimental deve contar com métodos de avaliação eficazes de seus parâmetros. Esta é uma observação importante quando se faz necessária a avaliação da nocicepção e da incapacitação articular em animais experimentais. O estabelecimento de novos critérios aos testes animais é fundamental para que processos inflamatórios articulares possam continuar sendo estudados, entendidos e resolvidos. Buscando contribuir neste sentido, este trabalho realizou a padronização do teste de incapacitação dinâmico (TID) para avaliação da incapacitação articular em modelos experimentais de artrite. Os resultados obtidos mostram que o TID é sensível na avaliação da incapacitação articular em modelos de artrite induzida por antígeno (AIA) ou por zimosana. Além disso é preditivo para o estudo do efeito farmacológico de drogas que interfiram na incapacitação articular como anti-inflamatórias ou analgésicas. Desde o início da década de 90, quando participação das células da glia na dor foi descrita, diversos trabalhos surgiram mostrando seu papel em diferentes modelos animais. A participação das células da glia espinais na dor e incapacitação em modelos experimentais de artrite e artrite reumatoide têm sido relatada, mas não há descrição desta participação em função do tempo de indução do processo inflamatório articular. Por meio de ferramentas farmacológicas e moleculares, este trabalho mostra que as células da glia, tanto espinais como do gânglio da raiz dorsal estão participando na gênese e manutenção da incapacitação inflamatória articular em modelo de AIA. A participação destas células ocorre por meio da liberação de IL-1? e TNF? em nível medular e pela primeira vez é mostrado que a ativação astrocítica parece preceder a ativação microglial neste modelo. / A good experimental model must rely on effective methods of evaluation of its parameters. This is an important observation when it is necessary to evaluate the articular nociception and disability in experimental animals. Establishing new criteria to test animals is essential for inflammatory joint can continue being studied, understood and resolved. Seeking help in this sense, this work constitutes a test dynamic weight bearing (DWB) standardization for assessment of articular incapacitation in experimental models of arthritis. The results show that the DWB is sensitive in assessing the impairment models articular antigen-induced arthritis (AIA) or zimosana. Furthermore is predictive for studying the pharmacological effects of drugs that interfere with articular incapacitation as antiinflammatory or analgesic. Since the early 90s, when participation of glial cells in pain was described, several studies have emerged showing its role in different animal models. The involvement of glial cells in the spinal pain and disability in experimental models of arthritis and rheumatoid arthritis have been reported, but no description of this contribution versus time of induction of joint inflammation. Through molecular and pharmacological tools, this work shows that the glial cells, both as the spinal dorsal root ganglio are participating in the genesis and maintenance of inflammatory joint incapacitation in AIA model. The participation of these cells occurs through the release of IL-1? and TNF? in the spinal cord and the first time it is shown that astrocytic activation appears to precede the microglial activation in this model.
23

Distribution of Nitric Oxide Synthase Isoforms in Neurons and Glial Cells Under Physiological or Pathological Conditions in the Rostral Ventrolateral Medulla of the Rat

Tsai, Po-chuan 15 August 2005 (has links)
The rostral ventrolateral medulla (RVLM) regulates vasomotor activity via sympathoexcitation and sympathoinhibition to maintain blood pressure. Nitric oxide synthesized by nitric oxide synthase (NOS) I and NOS II within RVLM is responsible for sympathoexcitation and sympathoinhibition respectively. In our previously study, under physiological condition RVLM neurons contain both NOS I and NOS II protein, and NOS III protein is expressed mainly on blood vessels. Under Mevinphos (Mev) intoxication, our previously study demonstrates that the expression of RVLM NOS I and II mRNA or protein are both increased under Mev intoxication phase I, and NOSII mRNA or protein are further increased under Mev intoxication phase II. On the other hand, in rat central nervous system, about 65% of total cells are glial cells, including astrocytes, microglia and oligodendrocytes. However, the expressions of NOS isoforms in RVLM glial cells still need to be determined. We used double immunofluorescence staining and confocal microscopy to investigate the distributions of NOS isoforms protein in RVLM neurons and glial cells under physiological condition and under pathological condition using Mev intoxication as our model. We further compared the distributions of NOS isoforms in RVLM neurons and glial cells under physiological or pathological conditions. The confocal images indicate that NOS I protein reactivity co-localized with neurons and microglia in the RVLM. NOS II protein reactivity co-localized with neurons, astrocytes and microglia. NOS III protein reactivity co-localized with blood vessels and microglia. The distributions of NOS isoforms protein reactivity in RVLM neurons and glial cells under Mev intoxication are the same as under physiological condition. Furthermore, the expressions of NOS I protein within neurons or microglia and NOS II in neurons, astrocytes or microglia are progressively increased under Mev intoxication. On the other hand, the expression of NOS III within microglia under Mev intoxication was similar to physiological condition. The population of NOS I-positive neurons or microglia, and NOS II-positive neurons, astrocytes or microglia increased under Mev intoxication. However the population of NOS III-positive microglia decreased under Mev intoxication. These results indicate that within RVLM, the distributions of NOS I are in neurons and microglia; NOS II are in neurons, astrocytes and microglia; NOS III are in blood vessels and microglia. We suggest that under Mev intoxication, the source of up-regulated NOS I protein includes neurons and microglia; and the up-regulated NOS II protein comes from neurons, astrocytes and microglia.
24

Serumalbumin bewirkt eine osmotische Schwellung der Müllerschen Gliazellen in der Netzhaut der Ratte

Löffler, Silvana 25 August 2015 (has links) (PDF)
Für die visuelle Wahrnehmung im Gehirn spielt die ungestörte Funktion von Neuronen und Gliazellen in der Netzhaut eine entscheidende Rolle. Viele schädigende Prozesse wie Entzündungen, Ischämien oder Traumata können zur Ödementstehung in der Netzhaut führen. Da die Netzhaut entwicklungsgeschichtlich einen vorverlagerten Teil des Zwischenhirns darstellt, lassen sich die pathophysiologischen Zusammenhänge, die zur Entstehung eines Netzhautödems führen, auch auf die Ödementstehung im Gehirn übertragen. Diese Arbeit beschäftigt sich mit dem Phänomen der Zellvolumenregulation von Müllerzellen – den hauptsächlich in der Netzhaut anzutreffenden Gliazellen – und leistet damit einen Beitrag zur Grundlagenerforschung der Ödementstehung in neuronalen Geweben. Die im Rahmen von Ödementstehungen regelmäßig zu beobachtenden Gefäßpermeabilitätserhöhungen führen in neuronalen Geweben auch zur Extravasation von Albumin. Unter diesem Gesichtspunkt untersucht die vorliegende Arbeit den Einfluss von bovinem Serumalbumin auf die Müllerzellen und die damit verbundenen Mechanismen am Modell der Netzhaut von Ratten.
25

Biomarkers of Optic Nerve Head Glial Cell Activation Following Biomechanical Insult

Rogers, Ronan 31 August 2012 (has links)
Glaucoma is a leading cause of irreversible blindness worldwide. Primary Open Angle Glaucoma is the most common form of the disease and can be characterized by the slow and irreversible apoptotic death of retinal ganglion cells, a unique optic nerve neuropathy resulting in loss of vision. Increased intra-ocular pressure is known to be a leading risk-factor for glaucoma, and lowering IOP is currently the only evidence based method for the clinical management of the disease. However the exact mechanism by which an elevated IOP leads to the death of the retinal ganglion cells is still poorly understood. By using previous finite element models of glaucoma to quantify the biomechanical environment within the optic nerve head we have built human primary cell culture models in an attempt to replicate aspects of early glaucomatous optic neuropathy. In these models we mimic the in vivo biomechanical environment in the lamina cribrosa by growing human optic nerve head astrocytes and lamina cribrosa cells on compliant substrates and subjecting the cells to deformation. Specifically, a global protein scan using isobaric tags for relative and absolute quantitation (iTRAQ) was performed on all the experiments to identify potential biomarkers for glaucoma. A secondary analysis using enzyme-linked immunosorbent assay (ELISA) identified extracellular proteins of interest. Over 520 proteins were identified in response to biomechnical strain from both cell types. Many of these proteins centred on TGF-, p53 and TNF, which have previously been shown to play a role in the pathogenesis of glaucoma. Proteins found in astrocytes were astrocytic phosphoprotein (PEA15), UDP-glucose dehydrogenase (UGDH), and annexin A4 (ANXA4). LC proteins were bcl-2-associated athanogene 5 (BAG5), nucleolar protein 66 (NO66) and Eukaryotic translation initiation factor 5A (eIF-5A). These proteomic results will enable a series of functional studies looking into the role select markers play in ONH glial cell activation, a process still not well understood. Candidates for this work will be prioritized based on novelty and relevance to mechanisms of cellular stress and death. We hypothesize that study of these molecular pathways will provide insight into this process, as well as improve our understanding of how glial activation contributes to the development of glaucomatous optic neuropathy.
26

Biomarkers of Optic Nerve Head Glial Cell Activation Following Biomechanical Insult

Rogers, Ronan 31 August 2012 (has links)
Glaucoma is a leading cause of irreversible blindness worldwide. Primary Open Angle Glaucoma is the most common form of the disease and can be characterized by the slow and irreversible apoptotic death of retinal ganglion cells, a unique optic nerve neuropathy resulting in loss of vision. Increased intra-ocular pressure is known to be a leading risk-factor for glaucoma, and lowering IOP is currently the only evidence based method for the clinical management of the disease. However the exact mechanism by which an elevated IOP leads to the death of the retinal ganglion cells is still poorly understood. By using previous finite element models of glaucoma to quantify the biomechanical environment within the optic nerve head we have built human primary cell culture models in an attempt to replicate aspects of early glaucomatous optic neuropathy. In these models we mimic the in vivo biomechanical environment in the lamina cribrosa by growing human optic nerve head astrocytes and lamina cribrosa cells on compliant substrates and subjecting the cells to deformation. Specifically, a global protein scan using isobaric tags for relative and absolute quantitation (iTRAQ) was performed on all the experiments to identify potential biomarkers for glaucoma. A secondary analysis using enzyme-linked immunosorbent assay (ELISA) identified extracellular proteins of interest. Over 520 proteins were identified in response to biomechnical strain from both cell types. Many of these proteins centred on TGF-, p53 and TNF, which have previously been shown to play a role in the pathogenesis of glaucoma. Proteins found in astrocytes were astrocytic phosphoprotein (PEA15), UDP-glucose dehydrogenase (UGDH), and annexin A4 (ANXA4). LC proteins were bcl-2-associated athanogene 5 (BAG5), nucleolar protein 66 (NO66) and Eukaryotic translation initiation factor 5A (eIF-5A). These proteomic results will enable a series of functional studies looking into the role select markers play in ONH glial cell activation, a process still not well understood. Candidates for this work will be prioritized based on novelty and relevance to mechanisms of cellular stress and death. We hypothesize that study of these molecular pathways will provide insight into this process, as well as improve our understanding of how glial activation contributes to the development of glaucomatous optic neuropathy.
27

Glutamatergic Regulation of Adult Goldfish Radial Glial Cells Via Group III Metabotropic Glutamate Receptors

Sacchi, Federico 05 December 2018 (has links)
Aromatase is an enzyme that converts androgens to estrogens. In teleosts, brain aromatase, also known as aromatase B (cy19a1b), is only expressed in radial glial cells (RGCs). This is in contrast to aromatase A, which is expressed in gonads. Estrogens such as estradiol (E2) modulate neurogenesis in the adult teleost brain. Recent studies show that E2 also differentially regulates aromatase B expression in goldfish RGCs. As a result, teleost RGCs are suggested to be involved in regulating neurogenesis. In addition, aromatase B expression in goldfish RGC is under the control of dopamine suggesting that neurons and neurotransmitters can regulate RGC function. Interestingly, goldfish RGC transcriptome data shows the expression of one group of metabotropic glutamate receptors (mGluRs), group III mGluRs, which suggests that glutamate may affect RGC function. In this thesis, I present my findings regarding potential glutamatergic regulation of RGCs. Firstly, I investigated the distribution of glutamatergic synaptic vesicles and RGCs in the female goldfish forebrain. Double-staining immunohistochemistry shows that vesicular glutamate transporter (vGLUT) 1/2-labelled glutamatergic synaptic vesicles are in close anatomical proximity to aromatase B-labelled RGCs, which suggests potential regulation of RGCs by glutamate. Glutamatergic regulation of cyp19a1b, cyclin D1 (ccnd1), cyclin A2 (ccna2), mGluR6b (grm6b), mGluR7 (grm7), and mGluR8b (grm8b) expression in cultured adult female goldfish RGCs was also examined. Results from pharmacological manipulations and qPCR data analysis show that selective activation of group III mGluRs decreased cyp19a1b, ccnd1, and ccna2 mRNA via inhibition of cAMP/PKA signalling. Furthermore, grm7 mRNA is positively regulated by cAMP-dependent signalling. The glutamate analog L-glutamic acid decreased cyp19a1b mRNA and increased ccnd1 and grm6b mRNA in a dose-dependent manner. This suggests that ccnd1 and grm6b expression may be regulated by glutamate receptors other than group III mGluRs, for example, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, which are expressed in cultured goldfish RGCs. It was found that E2 upregulated cyp19a1b, ccnd1 and grm7 mRNA. However, selective activation of group III mGluRs decreases the stimulatory effect of E2 on ccnd1 expression. My findings show that glutamate finely regulates RGC neurogenic and steroidogenic genes, which may implicate glutamate in the regulation of RGC differentiation, RGC proliferation, and neurogenesis in surrounding cells.
28

Serumalbumin bewirkt eine osmotische Schwellung der Müllerschen Gliazellen in der Netzhaut der Ratte: Serumalbumin bewirkt eine osmotische Schwellung derMüllerschen Gliazellen in der Netzhaut der Ratte

Löffler, Silvana 18 June 2015 (has links)
Für die visuelle Wahrnehmung im Gehirn spielt die ungestörte Funktion von Neuronen und Gliazellen in der Netzhaut eine entscheidende Rolle. Viele schädigende Prozesse wie Entzündungen, Ischämien oder Traumata können zur Ödementstehung in der Netzhaut führen. Da die Netzhaut entwicklungsgeschichtlich einen vorverlagerten Teil des Zwischenhirns darstellt, lassen sich die pathophysiologischen Zusammenhänge, die zur Entstehung eines Netzhautödems führen, auch auf die Ödementstehung im Gehirn übertragen. Diese Arbeit beschäftigt sich mit dem Phänomen der Zellvolumenregulation von Müllerzellen – den hauptsächlich in der Netzhaut anzutreffenden Gliazellen – und leistet damit einen Beitrag zur Grundlagenerforschung der Ödementstehung in neuronalen Geweben. Die im Rahmen von Ödementstehungen regelmäßig zu beobachtenden Gefäßpermeabilitätserhöhungen führen in neuronalen Geweben auch zur Extravasation von Albumin. Unter diesem Gesichtspunkt untersucht die vorliegende Arbeit den Einfluss von bovinem Serumalbumin auf die Müllerzellen und die damit verbundenen Mechanismen am Modell der Netzhaut von Ratten.
29

Wirkung von Osteopontin auf die osmotische Volumenregulation von Müller- und Bipolarzellen der Rattennetzhaut

Wahl, Vincent 21 August 2014 (has links)
Die Arbeit befasst sich mit dem Anschwellen von Neuronen und Gliazellen der Netzhaut, was einen wichtigen pathogenetischen Faktor des Netzhautödems darstellt. Osteopontin ist ein neuroprotektiver Faktor, der durch GDNF-Stimulation (glial cell line-derived neurotrophic factor) aus Müllerzellen ausgeschüttet wird. Die durch Osteopontin vermittelte Inhibition der osmotischen Zellschwellung von Müllerzellen der Ratte in Anwesenheit von Bariumionen oder H2O2 wird beschrieben und es wird dargestellt, dass Osteopontin keinen Einfluss auf die osmotische Zellschwellung der Bipolarzellen hat. Der für Müllerzellen beschriebene Effekt war dosisabhängig mit einer mittleren effektiven Konzentration von ca. 0,6 ng/ml. Durch den Einsatz pharmakologischer Rezeptor- oder Enzymblocker bzw. Antikörper werden die Schritte der Osteopontinwirkung identifiziert. Osteopontin induziert die Freisetzung von VEGF, Glutamat, ATP und Adenosin aus Müllerzellen. Die Osteopontinwirkung wurde verhindert durch die Blockade von spannungsabhängigen Natriumkanälen, T-Typ Calciumkanälen, Kalium- und Chloridkanälen. Der Effekt ist außerdem abhängig von einem intrazellulären Calciumsignal, der Aktivierung der Phospholipase C und der Proteinkinase C und der vesikulären Exozytose von Glutamat. Die Arbeit kommt zu dem Schluss, dass der neuroprotektive Effekt von Osteopontin teilweise durch das Verhindern eines Anschwellens der Müllerzellen und durch die Induktion einer Freisetzung von VEGF und Adenosin vermittelt wird.
30

Proliferace a diferenciace NG2 glií po ischemickém poškození mozku / Proliferation and differentiation of NG2-glia following ischemic brain injuries

Kirdajová, Denisa January 2016 (has links)
NG2-glia, a fourth major glial cell population, were shown to posses wide proliferation and differentiation potential in vitro and in vivo, therefore the aim of this study was to compare the rate of proliferation and differentiation potential of NG2-glia after different types of brain injuries, such as global and focal cerebral ischemia (GCI, FCI) or stab wound (SW), as well as during aging. Moreover, we aimed to determine the role of Sonic hedgehog (Shh) in NG2-glia proliferation/differentiation after FCI. We used transgenic mice, in which tamoxifen triggers the expression of red fluorescent protein (tdTomato) in NG2-glia and cells derived therefrom. Proliferation and differentiation potential of tdTomato+ cells in sham operated animals (controls) and those after injury were determined by immunohistochemistry employing antibodies against proliferating cell nuclear antigen and glial fibrillary acidic protein. FCI was induced by middle cerebral artery occlusion, GCI by carotid occlusion with hypotension and SW by sagittal cortical cut. Shh signaling in vivo was activated or inhibited by Smoothened agonist or Cyclopamine, respectively. Compared to controls, the proliferation rate of tdTomato+ cells was increased after all types of injuries, while it declined in aged mice (15-18- months-old) after...

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