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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.
201

DYNAMIC CILIARY LOCALIZATION IN THE MOUSE BRAIN

Katlyn M Brewer (18308818) 03 June 2024 (has links)
<p dir="ltr">Primary cilia are hair-like structures found on nearly all mammalian cell types, including cells in the developing and adult brain. Cilia establish a unique signaling compartment for cells. For example, a diverse set of receptors and signaling proteins localize within cilia to regulate many physiological and developmental pathways including the Hh pathway. Defects in cilia structure, protein localization, or cilia function lead to genetic disorders called ciliopathies, which present with various clinical features including several neurodevelopmental phenotypes and hyperphagia associated obesity. Despite their dysfunction being implicated in several disease states, understanding their roles in CNS development and signaling has proven challenging. I hypothesize that dynamic changes to ciliary protein composition contributes to this challenge and may reflect unrecognized diversity of CNS cilia. The proteins ARL13B and ADCY3 are established ciliary proteins in the brain and assessing their localization is often used in the field to visualize cilia. ARL13B is a regulatory GTPase important for regulating cilia structure, protein trafficking, and Hh signaling, while ADCY3 is a ciliary adenylyl cyclase thought to be involved in ciliary GPCR singaling. Here, I examine the ciliary localization of ARL13B and ADCY3 in the perinatal and adult mouse brain by defining changes in the proportion of cilia enriched for ARL13B and ADCY3 depending on brain region and age. Furthermore, I identify distinct lengths of cilia within specific brain regions of male and female mice. As mice age, ARL13B cilia become relatively rare in many brain regions, including the hypothalamic feeding centers, while ADCY3 becomes a prominent cilia marker. It is important to understand the endogenous localization patterns of these proteins throughout development and under different physiological conditions as these common cilia markers may be more dynamic than initially expected. Understanding regional and development associated cilia signatures and physiological condition cilia dynamic changes in the CNS may reveal molecular mechanisms associated with ciliopathy clinical features such as obesity.</p>
202

Overcoming therapeutic resistance in glioblastoma using novel electroporation-based therapies

Partridge, Brittanie R. 25 October 2022 (has links)
Glioblastoma (GBM) is the most common and deadliest of the malignant primary brain tumors in humans, with a reported 5-year survival rate of only 6.8% despite years of extensive research. Failure to improve local tumor control rates and overall patient outcome is attributed to GBM's inherent therapeutic resistance. Marked heterogeneity, extensive local invasion within the brain parenchyma, and profound immunosuppression within the tumor microenvironment (TME) are some of the unique features that drive GBM therapeutic resistance. Furthermore, tumor cells are sequestered behind the blood-brain barrier (BBB), limiting delivery of effective therapeutics and immune cell infiltration into the local tumor. Electroporation-based therapies, such as irreversible electroporation (IRE) and second generation, high-frequency IRE (H-FIRE) represent attractive alternative approaches to standard GBM therapy given their ability to induce transient BBB disruption (BBBD), achieve non-thermal tumor cell ablation and stimulate local and systemic anti-tumor immune responses without significant morbidity. The following work explores the use of H-FIRE to overcome GBM-induced therapeutic resistance and improve treatment success. Chapter 1 opens with an overview of GBM and known barriers to treatment success. Here, we emphasize the utility of spontaneous canine gliomas as an ideal translational model for investigations into novel treatment approaches. Chapter 2 introduces novel ablation methods (i.e. IRE/H-FIRE) capable of targeting treatment-resistant cancer stem cells. The focus of Chapter 3 is to highlight IRE applications in a variety of spontaneous tumor types. In Chapter 4, we investigate the feasibility and local immunologic response of percutaneous H-FIRE for treatment of primary liver tumors using a spontaneous canine hepatocellular carcinoma (HCC) model. In chapter 5, we characterize the mechanisms of H-FIRE-mediated BBBD in an in vivo healthy rodent model. In Chapter 6, we characterize the local and systemic immune responses to intracranial H-FIRE in rodent and canine glioma models to enhance the translational value of our work. Collectively, our work demonstrates the potential for H-FIRE to overcome therapeutic resistance in GBM, thereby supporting its use as a novel, alternative treatment approach to standard therapy. / Doctor of Philosophy / Glioblastoma (GBM) is the most common and deadliest form of primary brain cancer in humans, with only 6.8% of people surviving 5-years after their diagnosis. GBM is characterized by a number of unique features that make it resistant to standard treatments, such as surgery, radiation and chemotherapy. Examples include: (1) extensive invasion of tumor cells into the brain, making complete removal via surgery very difficult; (2) tumor cells are protected by a structure called the blood-brain barrier (BBB), which restricts the entry of most drugs (i.e. chemotherapy) and many immune cells, into the brain, thereby preventing them from reaching tumor cells; (3) tumor cells produce substances that block the immune system from being able to detect the tumor itself, which allows it to continue to grow undetected. High-frequency irreversible electroporation (H-FIRE) represents a new approach for the treatment of GBM. H-FIRE uses electric pulses to temporarily or permanently injure cell membranes without the use of heat, which allows for very precise treatment. The following work explores the ways in which H-FIRE can interfere with specific GBM features that drive its resistance to treatment. Here, we demonstrate that H-FIRE is capable of temporarily disrupting the BBB and characterize the mechanisms by which this occurs. This allows for drugs and immune cells within the blood to enter the brain and access the tumor cells, particularly those extending beyond the visible tumor mass and invading the brain. We also illustrate the potential for H-FIRE treatment within the brain to stimulate local and systemic immune responses by causing the release of proteins from injured cells. Similar to a vaccine, these proteins are recognized by the immune system, which becomes primed to help fight off cancer cells within the body. The end result is an anti-tumor immune response. Collectively, this work supports the use of H-FIRE as an alternative treatment approach to standard therapy for GBM given its potential to overcome certain causes of treatment resistance.
203

Beteiligung der Indolamin 2,3-Dioxygenase (IDO) an Immunregulation des zentralen Nervensystems

Kwidzinski, Erik 13 February 2006 (has links)
In Europa stellt die Multiple Sklerose (MS) die häufigste neuroimmunologische Erkrankung des zentralen Nervensystems (ZNS) dar. Relevante Daten zum Krankheitsverlauf der MS wurden durch Untersuchungen im Tiermodell der experimentellen autoimmunen Enzephalomyelits (EAE) gewonnen. Nach gegenwärtigem Kenntnisstand wandern autoreaktive T-Zellen vom T-Helfer-1 (Th-1) Typ in das ZNS ein und lösen eine gegen Bestandteile der Markscheide gerichtete Entzündung aus. Diese Zellen exprimieren große Mengen des für sie typischen Zytokin Interferon-gamma (IFN-gamma), was in zahlreichen Zelltypen die Expression des Tryptophan degradierenden Enzyms Indolamin 2,3-Dioxygenase (IDO) induziert. Seit 1998 ist bekannt, dass die Inhibition der IDO zu einer durch T-Zellen vermittelten Abstoßung allogener Feten führt. Diese immunregulatorische Funktion von IDO konnte auf den schnellen Abbau der essentiellen Aminosäure Tryptophan und der im folgenden Abbauweg synthetisierten T-Zell-toxischen Metabolite zurückgeführt werden. Da im entzündeten ZNS-Gewebe während der MS und der EAE das IDO induzierende Zytokin IFN-gamma ebenfalls exprimiert wird, sollte in der vorliegenden Arbeit untersucht werden in wie weit die IDO an der Immunregulation des ZNS unter autoimmuner Neuroinflammation während EAE, beteiligt ist. Mittels HPLC konnte gezeigt werden, dass die relative IDO Aktivität im ZNS während der akuten und der Erholungsphase der Erkrankung signifikant gesteigert ist. Erfolgte ab dem Ausbruch der Erkrankung die systemische Inhibition der IDO Aktivität mit dem spezifischen IDO-Inhibitor 1-Methyl-Tryptophan, so führte dies zu einem signifikant schwereren Krankheitsverlauf im Vergleich zu Kontrolltieren. Mittels Immunzytochemie wurde gezeigt, dass aktivierte Mikroglia IDO im entzündeten ZNS und in Zellkultur nach IFN-gamma Stimulation exprimieren. Aufgrund von RT-PCR Analysen weiterer Enzyme des Kynureninweges konnte dessen Regulation während EAE nachgewiesen werden Entlang dieses Stoffwechselweges werden T-zell-toxische Tryptophanmetabolite gebildet die an der Eliminierung autoreaktiver T-Zellen im ZNS während der Erholungsphase der EAE beteiligt sein könnten und somit die aktivierten Th1 Zellen im ZNS einen antiinflammatorischen Rückkopplungsmechanismus auslösen. / Multiple sclerosis (MS) is the most widespread neuroimmunological disease of the central nervous system (CNS) in Europe. By applying the animal model of MS, experimental autoimmune encephalomyelitis (EAE), important insights into the disease course of MS have been gained. At present it is accepted that at the onset of the disease myelin-reactive T helper type 1 (Th1) cells infiltrate the CNS and induce autoimmune neuroinflammation. Activated Th1 cells express high amounts of the cytokine interferon-gamma (IFN-gamma). This pro-inflammatory signaling molecule is known to induce the expression of the tryptophan-degrading enzyme Indolmaine 2,3- Dioxygenase (IDO) in several cell types. Since 1998 it is known that inhibition of IDO induces the T cell-mediated rejection of allogeneic concepti in mice. The mechanism of this immunregulatory function of IDO was shown to be due to the degradation of the essential amino acid tryptophan and the subsequent synthesis of T cell toxic metabolites. Since the IDO-inducing cytokine IFN-gamma is also expressed within inflamed CNS tissue during MS and EAE, the present work investigated the role of IDO in immunregulation of the CNS during autoimmune neuroinflammation in the EAE model. A significant increase in relative IDO activity within the CNS during the acute and remission phases of EAE was identified by HPLC analysis. Systemic inhibition of IDO activity by the specific IDO inhibitor 1-methyl-tryptophan reduced the remission and exacerbated the progression of the disease in comparison to control animals. Activated microglia were identified by immunocytochemistry as IDO-expressing cells within the acute inflamed CNS and in cell culture after IFN-gamma stimulation. Enzymes following IDO in the kynurenine pathway were shown by RT-PCR to be up-regulated in the disease course. The analyzed enzymes are known to produce T cell toxic tryptophan metabolites and might therefore be involved in the elimination of autoreactive T cells from CNS tissue. In conclusion, the presented data support the view that autoreactive Th1 cells in the CNS induce a self-limiting negative feedback mechanism which limits the spread of inflammation, thereby reducing bystander damage in the CNS.
204

Das 20S Proteasom in Astrozyten und seine Rolle bei Entzündungsprozessen im Zentralnervensystem

Siele, Dagmar 06 November 2009 (has links)
Das Proteasom ist das zentrale proteolytische System in eukaryontischen Zellen, welches die Mehrzahl der intrazellulären Proteine abbaut. Da viele essentielle Prozesse in der Zelle proteolytisch reguliert werden, besitzt das Proteasom eine außerordentliche biologische Bedeutung. Die Erforschung des Proteasoms im ZNS steht erst am Anfang, dennoch zeigen zahlreiche Untersuchungen, dass Inhibition bzw. Störung des Ubiquitin-Proteasom-Systems mit vielen neurologischen oder neurodegenerativen Erkrankungen einhergeht. Deshalb wurde in der vorliegenden Arbeit nach Veränderungen des Proteasoms in Entzündungsprozessen im ZNS am Beispiel der experimentellen autoimmunen Encephalomyelitis (EAE) in der Maus gesucht. Schwerpunkt der Untersuchungen war das Proteasom in Astrozyten. Astrozyten stellen die größte Gruppe unter den Gliazellen dar und besitzen vielfältige Funktionen, zu denen neben klassischen housekeeping Funktionen auch Aufgaben bei der Immunantwort zählen. Der enge und für Neurone essentielle Kontakt prädestiniert Astrozyten, neuronale Erkrankungen mit auszulösen und zu modulieren. In dieser Arbeit wurden in primär isolierten Astrozyten Immunproteasomen (IP) detektiert. Durch Experimente mit der Astrozytenzelllinie TSA-3 konnte gezeigt werden, dass Astrozyten im unstimulierten Zustand nur Standardproteasom besitzen, auf Stimulation jedoch mit der Bildung von IP reagieren. Das Fehlen von IP in Astrozyten unter in vivo Bedingungen deckte sich mit den Strukturanalysen von Proteasomen aus dem Großhirn von Mäusen verschiedener Altersstufen, den mRNA-Expressionsanalysen sowie immunhistologischen Untersuchungen von Hirngewebe aus EAE Mäusen. Die aus dem Großhirn isolierten Proteasomen nach Induktion einer EAE durch Myelin-Oligodendrocyten-Glycoprotein (MOG) enthielten keine IP. Dennoch erfolgt eine Aktivitätsveränderung im Proteasom vor dem Auftreten der ersten EAE Symptome, die in vitro zu einer effizienteren Epitopgenerierung aus einem MOG-Peptid führt. / The proteasome is the central proteolytic system in all eukaryotic cells catalysing the degradation of the majority of intracellular proteins. Since many essential processes are proteolytically controlled, the proteasome is of crucial biological importance. Yet numerous investigations show that many neurological or neurodegenerative diseases go along with inhibition and/or changes of the ubiquitin-proteasome-system. Therefore the present thesis investigates the proteasome system during inflammatory processes in the CNS, namely during experimental autoimmune encephalomyelitis (EAE), a widely used animal model for human multiple sclerosis. Main focus of the investigations was the proteasome in astrocytes. Astrocytes embody the largest group of glial cells in the CNS and possess various functions. Apart from classical housekeeping functions astrocytes take part in the immune reaction in the CNS. Their close and essential contact to neurons predestines astrocytes to cause and modulate neural diseases. In the present work immune proteasome subunits were detected in primary astrocytes isolated from newborn mice. On the other hand, when grown under resting conditions the murine astrocyte cell line, TSA-3, contains standard proteasome only, however, when treated with interferon gamma, these cells produce immune proteasomes, too. Subunit analyses of proteasomes isolated from the cerebrum of mice of different age, measurement of the mRNA expression level of proteasome subunits as well as immune-histological investigations of brain tissue from mice confirmed the absence of immune proteasome in astrocytes under in vivo conditions. Proteasomes isolated from mouse brain after induction of EAE by active immunization with myelin oligodendrocyte glycoprotein (MOG) did not contain immune subunits. Nevertheless an activity change in the proteasomes isolated from brains before onset of EAE was observed, which lead to a more efficient epitope generation from MOG peptide.
205

Triaxialité et isomèrisme à hauts spins dans les noyaux proches de la fermeture de couche N = 82 / Triaxiality and seniority isomeric states in nuclei near the N = 82 shell closure

Léguillon, Romain 17 October 2013 (has links)
L'existence de noyaux triaxiaux a fait l'objet d'un débat de longue date. La possibilité de la triaxialité mole et rigide a été proposée très tôt, et de nombreuses études théoriques et expérimentales ont été consacrées à ce phénomène intrigant. Plus récemment, deux marqueurs uniques de la triaxialité dans les noyaux ont été intensivement étudiés : le mouvement d'oscillation de l'axe de rotation (wobbling) et la chiralité dynamique. Ces types exotiques de mouvement ont été observées dans des régions spécifiques du tableau nucléaire : le mouvement d'oscillation dans les noyaux de Lu impair-pair avec A ~ 160, la chiralité principalement dans les noyaux impair-impair et pair-impair avec A ~ 130. Nous avons récemment étudié les noyaux de Nd à très hauts spins et identifié plusieurs bandes, qui ont été interprétées comme la manifestation de divers types de mouvement collectif : rotation suivant un axe incliné, rotation suivant les axes longs et courts, mouvement de wobbling et bandes chirales. Un autre phénomène révélé par nos résultats récents sur les noyaux de Nd avec seulement quelques trous neutroniques par rapport à la fermeture de couche N = 82, est la coexistence de forme. En effet, ces noyaux sont prévus pour avoir des isomères de hauts spins construis sur une forme sphérique, coexistant avec des bandes triaxiales, ou des formes très voire super-déformées . Ma thèse se compose de deux expériences. Tout d'abord, j'ai préparé, exécuté et analysé une expérience réalisée au « Research Center of Nuclear Physics » (RCNP) de l' Université d'Osaka . Cette expérience visait à étudier les isomères de hauts spins et à développer les schémas de niveaux des noyaux de 135La, 136La et 136Ba. Nous avons utilisé un faisceau radioactif de 17N de 80 MeV créé par la réaction directe de 18O sur une cible 9Be et sélectionné à l'aide d'un spectromètre achromatique. Le faisceau radioactif de 17N bombardait une cible de 124Sn de 20 mg/cm2 d'épaisseur pour produire les noyaux d'intérêt par une réaction de fusion-évaporation. Cette thèse présente les résultats obtenus pour le 135La, qui comprennent la construction et la discussion du schéma de niveau et la mesure de la durée de vie de deux isomères connus. La deuxième partie de la thèse consiste en l'analyse de deux expériences différentes réalisée en utilisant la même combinaison de faisceau-cible 48Ca + 96Zr à une énergie légèrement différentes et deux dispositifs expérimentaux différents, EUROBALL et JUROGAM II + RITU + GREAT, pour étudier les isotopes du néodyme de 138Nd à 141Nd. Mon travail a été axé sur les noyaux pair-pair de 138Nd et 140Nd, avec un accent particulier sur le 140Nd. La multitude de bandes de spin élevé observées dans ce noyau sont discutées dans le cadre du modèle « Cranked Nilsson - Strutinsky » (CNS) et du modèle « Tilted Axis Cranking » (TAC). Les bandes de hauts spins observées dans les noyaux de 138-141Nd sont toutes interprétées comme basées sur un minimum d'énergie associé à une déformation triaxiale. Elles représentent donc un fort soutien à l'existence de la forme nucléaire triaxiale stable à hauts spins. L'isomère de haut spin 27– a également été identifié dans le 140Nd qui, combinée avec l'isomère 20+ précédemment connu dans le même noyau va permettre d'extraire pour la première fois une valeur expérimentale de la différence d'énergie entre les orbitales πh11/2 et π(d5/2g7/2) à hauts spins. / The existence of triaxial nuclei has been the subject of a long standing debate. The possibility of soft and rigid triaxiality has been proposed very early, and many theoretical and experimental studies have been devoted to this intriguing phenomenon since then. More recently two unique fingerprints of triaxiality in nuclei have been intensively studied : the wobbling motion and the dynamic chirality. These exotic types of motion were observed in specific regions of the nuclear chart : the wobbling motion in the odd-even Lu nuclei with A ∼ 160, the chirality primarily in the odd-odd and odd-even nuclei with A ∼ 130 nuclei. We have recently studied the Nd nuclei up to very high spins and identified several bands, which were interpreted as the manifestation of various types of collective motion : tilted axis rotation, principal axis rotation along the short and long axes, wobbling motion and chiral bands. Another phenomenon revealed by our recent results on the Nd nuclei with neutron numbers just below the N=82 shell closure, is the shape coexistence. In fact, these nuclei are predicted to have high-spin seniority isomers built on a spherical shape, coexisting with bands built on either triaxial, highly or even superdeformed shapes.My PhD consists of two experiments. Firstly I have prepared, performed and analysed an experiment realized at the Research Center of Nuclear Physics (RCNP) of the Osaka University. This experiment was performed to study the isomeric states and to develop the level schemes of the 135La, 136La and 136Ba nuclei. We have used a radioactive 17N beam of 80 MeV created by the stripping reaction of 18O on a 9Be target and selected using an achromatic spectrometer. The 17N radioactive beam bombarded a 20 mg/cm2 124Sn target to produce the nuclei of interest by a fusion-evaporation reaction. The present thesis presents the results obtained for 135La, which include the construction and discussion of the level scheme and the measurement of the lifetime of two known isomers. The second part of the thesis consists in the analysis of two different experiments performed using the same beam-target combination 48Ca + 96Zr at slightly different beam energies and two different settups, EUROBALL and JUROGAM II + RITU + GREAT, to study the neodymium isotopes from 138Nd to 141Nd. My work was focused on the even-even 138Nd and 140Nd nuclei, with special emphasis on 140Nd, which is discussed in the present thesis. The multitude of high-spin bands observed in this nucleus are discussed in the framework of Cranked Nilsson-Strutinsky (CNS) and Tilted Axis Cranking (TAC) models. The observed high-spin bands in 138−141Nd which are consistently interpreted as based on an energy minimum at triaxial deformation, represent a strong support for the existence of stable triaxial nuclear shapes at high spins. A 27– high-spin isomer has also been identified in 140Nd, which combined with the previous known 20+ isomer in the same nucleus allow to extract for the first time an experimental value for the energy difference between the πh11/2 and π(d5/2g7/2) orbitals at high spins.
206

Assoziation des PDCD1 rs11568821 GG-Genotyps mit stärkerer Morbidität bei Intensivpatienten mit Krankheitsbild Sepsis: Vergleich der SOFA-Sub-Scores / Association of the PDCD1 rs11568821 GG-genotype with higher morbidity of patients with sepsis at ICU: Comparison of the SOFA-sub-scores

Gerber, Sebastian 30 June 2016 (has links)
No description available.
207

Vergleich primärer Peritonealmakrophagen und Mikrogliazellen von jungen und alten Mäusen bezüglich ihrer Bakterienphagozytose und Freisetzung inflammatorischer Mediatoren in vitro / Comparison of primary peritoneal macrophages and microglial cells from young and aged mice regarding their phagocytosis of bacteria and release of inflammatory mediators in vitro

Kaufmann, Annika 23 November 2016 (has links)
No description available.
208

Caracterização do perfil de síndromes dolorosas, psicofísica e medidas de excitabilidade cortical em doentes com neuromielite óptica controlada / Characterization of pain, psychophysics and cortical excitability profile in patients with controlled neuromyelitis optica spectrum disorders

Silva, Fernanda Valerio da 03 April 2019 (has links)
Introdução: Neuromielite óptica (NMO) é uma doença inflamatória desmielinizante do sistema nervoso central associado com auto anticorpo anti-aquaporina 4 (AQP4-Ab) em até 90% dos casos e com anticorpo anti glicoproteína de mielina oligodendrocítica (MOG-IgG) em cerca de 20% dos indivíduos negativos para AQP4-Ab. A apresentação clínica típica do NMO inclui neurite óptica grave (ON), mielite transversa longitudinalmente extensa (MTLE) e lesões do tronco encefálico conhecidas por causar náuseas,vômitos e soluços intratáveis. A dor é um dos sintomas mais frequentes e incapacitantes dessa síndrome. Sabe-se que afeta até 85% dos indivíduos, que é mais intensa e responde menos aos tratamentos usuais quando comparados aos pacientes com esclerose múltipla. O objetivo deste estudo foi caracterizar as síndromes dolorosas em indivíduos na fase crônica livre de recidiva da NMO. A doença também foi considerada um bom modelo para estudar os mecanismos de dor após lesão medular. Métodos: Trata-se de um estudo longitudinal, composto por duas avaliações. A avaliação para entrada no estudo consistiu em um exame neurológico complete padronizado, a fim de determinar as síndromes dolorosas principal e secundária de acordo com seu mecanismo e nível. Os pacientes foram convidados a preencher questionários avaliando a dor (Inventário breve de dor [BPI], Questionário de dor McGill [MPQ], inventário de sintomas de dor neuropática [NPSI]), espasmos tônicos dolorosos, sinal de Lhermitte, incapacidade (EDSS, Barthel ADL), ansiedade e depressão (escala hospitalar de ansiedade e depressão [HADS]), catastrofização (escala de pensamentos catastróficos na dor [PCTS]), disfunção urinária e fecal (questionário de bexiga hiperativa [OABV8], escore de sintomas prostáticos internacionais [IPSS]). Também foram realizados teste quantitativo sensitivo (QST) em área controle (com sensibilidade normal) e área de maior dor e medidas de excitabilidade cortical bilaterais (CE). Imagens prévias de ressonância magnética de encéfalo e medula espinhal foram revistos. Foi realizada uma consulta de acompanhamento entre 6 e 18 meses após a primeira visita, na qual a síndrome dolorosa principal foi reavaliada e os pacientes foram solicitados a preencher questionários (DN-4, BPI, MPQ, BPI, NPSI) sobre a dor. Resultados: Setenta e dois pacientes foram incluídos. Foram identificados 53 (73,6%) indivíduos com dor crônica e 19 (26,3%) sem dor. Quarenta (55,6%) pacientes apresentaram dor neuropática (NP) e 13 (18,1%) dor não neuropática (não-NP). Entre os 53 indivíduos com dor crônica, 38 (71,7%) tinham mais de uma síndrome dolorosa. Dor neuropática no nível sensitivo foi a síndrome dolorosa mais prevalente, sendo observada em 31 doentes (58,5% do total de pacientes com dor). O grupo com dor não-neuropática teve dor lombar como a síndrome mais comum, afetando 8 (61,5%) indivíduos. O grupo com dor neuropática teve um número significativamente maior de dermátomos afetados por alodínea dinâmica (0,8 ± 1,6, comparado a zero dermátomos nos outros 2 grupos, p = 0,004) e estática (0,7 ± 1,3 comparado a 0 no grupo com dor não-neuropática e 0,1 ± 0,5 dermátomos no grupo sem dor). A hiperpatia em nível foi significativamente mais prevalente no grupo com dor neuropática: 39 (97,5%) nesse grupo, contra 10 (76,9%) e 12 (68,4%) nos grupos dor não-neuropática e sem dor (p = 0,013). Os pacientes com dor neuropática apresentaram desempenho significativamente pior quando comparados aos sem dor, no PCS-12 (componente físico do SF-12), (32,5 ± 8 e 43,3 ± 11, respectivamente). O PCS-12 correlacionou-se com a intensidade da dor no BPI nos grupos dor neuropática (r = -0,387, p = 0,014) e não-neuropática (r = -0,734, p = 0,004). Dentro do grupo com dor neuropática, 16 (80%) pacientes relataram prurido na área de dor, enquanto apenas 1 (33,3%) paciente com dor não neuropática relatou o mesmo (p < 0,001). O QST apresentou maiores limiares para a detecção de estímulos quentes dentre aqueles com dor neuropática, quando comparado ao grupo com dor não-neuropática (41,3 ± 5,6 e 36,9 ± 3, respectivamente, p = 0,045). As amplitudes do potencial evocado motor a 120 e 140% foram significativamente menores nos dois grupos com dor quando comparados aos pacientes sem dor. A avaliação de acompanhamento foi realizada em 68 pacientes e 50 (73,5%) relataram dor. A dor neuropática do nível foi novamente a síndrome dolorosa mais prevalente, afetando 29 (58%) indivíduos. Três pacientes inicialmente sem dor relataram na o sintoma na segunda visita. A taxa de incidência de dor foi de 17,7 por 100 pessoas-ano. Onze pacientes que haviam relatado dor na entrada do estudo tinham uma síndrome de dor diferente na segunda avaliação (20,8% da amostra original). O grupo com dor neuropática teve uma diminuição significativa na intensidade do BPI (de 5,6 ± 1,9 para 4,8 ± 2, p = 0,039). O escore total do MPQ diminuiu significativamente em ambos os grupos com dor neuropática (de 9 ± 2,4 para 8 ± 3,1, p = 0,014) e naqueles com dor não-neuropática (9,2 ± 2,5 a 7 ± 4, p = 0,031). Conclusão: A dor é prevalente em pacientes com NMO e a dor neuropática de nível é a síndrome mais comum. A incidência de novas dores e alterações nas síndromes dolorosas não está relacionada à nova atividade inflamatória, mas ao dano estrutural permanente crônico na medula espinhal e tronco cerebral secundário à atividade autoimune prévia. A avaliação das síndromes dolorosas é importante para o tratamento correto desse sintoma e deve ser reavaliada regularmente, mesmo em pacientes sem novas recidivas clínicas / Introduction: Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system. It is associated with anti-aquaporin 4 autoantibody (AQP4-Ab) in up to 90% of cases and with anti-myelin oligodendrocyte glycoprotein (MOG-IgG) in around 20% of subjects negative to AQP4-Ab. The typical clinical presentation of NMOSD includes severe optic neuritis (ON), longitudinally extensive transverse myelitis (LETM) and brainstem lesions known to cause intractable nausea, vomiting and hiccups. Pain is one of the most frequent and disabling symptoms in this syndrome. It is known to affect up to 85% of subjects with NMO which is more intense and less responsive to usual treatments when compared to multiple sclerosis patients. The aim of this study was to fully characterise all pain syndromes in individuals in the chronic relapse-free phase of NMO. The disease was also deemed a good model to study pain mechanisms in spinal cord injuries. Methods: This is a longitudinal study, comprised by 2 evaluations. The Baseline study entry visit consisted of a full standardized neurological examination, in order to determine the main and secondary pain syndrome according to its mechanism and level. Patients were requested to fill questionnaires evaluating pain (Douleur Neuropathique-4 [DN-4], brief pain inventory [BPI], Short-form McGill Pain Questionnaire [MPQ], Neuropathic pain symptoms inventory [NPSI]), painful tonic spasms, Lhermitte sign, hiccups, orthostatic intolerance, persistent nausea, pruritus, fatigue (modified fatigue scale), Uhthoff phaenomenon, quality of life (SF-12), disability (EDSS, Barthel ADL), anxiety and depression (Hospital anxiety and depression scale [HADS]), catastrophizing (PCTS), urinary and faecal dysfunction(OABV8,IPSS). Quantitative sensory test (QST) and measures of cortical excitability (CE) were performed. Previous brain and spinal cord MRIs were reviewed. A follow up visit was done between 6 and 18 months after the first visit, in which the main pain syndrome was reassessed and patients again were requested to fil pain questionnaires (DN-4, BPI, MPQ, BPI, NPSI) and report painful tonic spasms and Lhermitte sign. Results: Seventy-two patients were included. We identified 53 (73.6%) patients with chronic pain and 19 (26.3%) without any chronic pain syndrome. Forty (55.6%) patients had neuropathic pain (NP) and 13 (18.1%) had non-neuropathic pain (non-NP). Amongst those 53 subjects with chronic pain, 38 (71.7%) had more than one pain syndrome. NP at the sensory level was the most prevalent pain syndrome, being observed in 31 patients (58.5% of the total pain patients). Amid the non-NP patients, low back pain was the most common pain syndrome, affecting 8 (61.5%) subjects. NP group had a significantly higher number of dermatomes affected by allodynia to brush (0.8 ± 1.6, compared to zero dermatomes in the other 2 groups, p = 0.004) and to pressure (0.7 ± 1.3 compared to no 0 in the non-NP group and 0.1 ± 0.5 dermatomes in the no pain group). At-level hyperpathia affected a significantly proportion of patients with NP: 39 (97.5%) in this group, versus 10 (76.9%) and 12 (68.4%) in the non-NP and no pain groups (p= 0.013). Patients with NP had significantly worse performance when compared to those without pain, in the PCS-12 (physical component of the SF-12), (32.5 ± 8 and 43.3 ± 11, respectively). PCS-12 correlated with BPI intensity pain amid NP (r= -0.387, p= 0.014) and non-NP (r= -0.734, p= 0.004) groups. Within the group with neuropathic pain, 16 (80%) of patients reported itching on the pain area, whereas only 1 (33.3%) patient with non-neuropathic pain reported the same (p < 0.001). QST showed higher thresholds for warm stimuli detection within NP group, when compared to non-NP (41.3 ± 5.6 and 36.9 ± 3, respectively, p= 0.045) group. Motor evoked potential amplitudes at 120 and 140% were significantly lower in both groups with pain when compared to those without pain. The follow up assessment was done in 68 patients and 50 (73.5%) reported pain. At-level NP was the most prevalent syndrome, affecting 29 (58%) subjects. Three patients initially without pain reported it in the follow up visit. Incidence rate of pain was 17.7per 100 persons-year. Eleven patients who had reported pain upon study entry had a different pain syndrome on the second evaluation (20.8% of the original sample). NP group had a significant decrease in BPI intensity (from 5.6± 1.9 to 4.8±2, p= 0.039). MPQ total score significantly decreased in both groups with NP (from 9±2.4 to 8±3.1, p=0.014) and in those with non-NP (9.2±2.5 to 7±4, p=0.031). Conclusion: Pain is prevalent in patients with NMO and at-level NP is the most common syndrome. The incidence of new pain and changes in its syndromes is not related to new inflammatory activity but to the permanent chronic structural damage in the spinal cord and brainstem secondary to previous autoimmune activity. Assessment of pain syndromes is important for its treatment and they should be re-evaluated regularly even in patients without new clinical relapses
209

Efeito da administração aguda e repetida de fencanfamina sobre o valor reforçado do estímulo / Effect of acute and repeated administration of Fencamfamine on reinforcement value of stimuli.

Garcia-Mijares, Miriam 02 August 2000 (has links)
A fencanfamina (FCF) é um agonista indireto do sistema dopaminérgico que tem efeitos neurais e comportamentais similares aos observados com outras drogas estimulantes como a anfetamina ou a cocaína (COC). O presente trabalho teve como objetivo avaliar o efeito da administração aguda e repetida de FCF sobre o valor reforçador dos estímulos (Re). Foi usada a equação de igualação proposta por Herrnstein (1970) para avaliar esse efeito motivacional Foi também medido o efeito dessa droga sobre a taxa de respostas e a capacidade motora (k). Três experimentos foram realizados. Nos três experimentos o efeito da FCF foi testado em ratos treinados em um esquema múltiplo de sete componentes de diferentes Vls. Nos Experimentos 1 e 2 (E1 e E2, respectivamente) três doses agudas de FCF (0,88 mg/kg, 1,75 mg/kg e 3,5 mg/kg) foram administradas i.p. No E1 o reforçador foi água e no E2 reforçador foi sacarose. Em ambos os experimentos, o efeito da droga sobre os parâmetros estudados foi semelhante: as três doses de FCF aumentaram a taxa de respostas e diminuíram Re, sem alterar k. No Experimento 3, seis injeções de veiculo (Grupo VEI) ou de 1,75 mg/kg de FCF (Grupo DROGA) foram administradas i.p. intermitentemente aos sujeitos a fim de promover sensibilização comportamental. Após sete dias de suspensão da droga, foi administrada uma dose de 0,88 mg/kg de FCF em animais de ambos os grupos e foi medido o efeito sobre a taxa de respostas, k e Re. Os resultados obtidos mostraram que a administração repetida de FCF não alterou o efeito dessa droga sobre os parâmetros estudados. Os resultados são consistentes com os dados que mostram que a FCF tem efeitos sobre o comportamento similares aos de outros estimulantes, e apoiam a hipótese de que o aumento da taxa de respostas observado após a administração da FCF está relacionado a mudanças no valor reforçador dos estímulos, o que sugere um efeito motivacional e não motor. Além disso, os resultados sustentam as hipóteses que relacionam o sistema dopaminérgico ao processo do reforço. A falha na obtenção de sensibilização após a administração repetida de FCF poderia estar relacionada à dose utilizada ou ao numero de injeções administradas. / Fencanfamina (FCF) is an indirect dopaminergic agonist with neural and behavioral effects similar to those observed for other stimulant drugs such as the amphetamine or cocaine (COC). The aim of the present investigation was to evaluate the effect of acute and repeated administration of FCF on the reinforcing value (Re) taken as a motivational index. The Herrnstein hyperbole equation (1970) was used to evaluate this motivacional effect. The effects of FCF on response rate and motor capacity (k) where also observed. Three experiments were conducted. In all of them the effect of FCF was tested on rats trained on seven VI multiple schedule. In Experiments 1 and 2 (E1 and E2, respectively) three acute doses of FCF (0.88 mg/kg, 1.75 mg/kg and 3.5 mg/kg) were administered (i.p.) The reinforcer was water (E1) or sacarose (E2). In both experiments, the effect of the drug on the parameters studied was similar: the three doses of FCF increased the response rate, decreased Re and had no effect on k. In Experiment 3, six injections of vehicle (VEI Group) or 1.75 mg/kg of FCF (DROGA Group) were intermittently administered (i.p.) in order to promote sensitization. Seven days after drug withdrawal a single dose of 0.88 mg/kg of FCF was administered to animals in both groups and the effect on response rate, k and Re was measured. Results showed that repeated administration of FCF did not change the effect of this drug on the parameters investigated. These results are consistent with the evidence showing that FCF has behavioral effects similar to those reported for other stimulants and support the interpretation that increases in response rate are primarily related to changes in reinforcing value. Thus they probably reflect a motivational effect of the drug. Moreover, the results support the hypotheses that associate the dopaminergic system to the process of reinforcement. It is speculate that the failure to obtain sensitization after repeated administration of FCF could be related to dosage or number of injections.
210

Triaxialité et isomèrisme à hauts spins dans les noyaux proches de la fermeture de couche N = 82

Léguillon, Romain 17 October 2013 (has links) (PDF)
L'existence de noyaux triaxiaux a fait l'objet d'un débat de longue date. La possibilité de la triaxialité mole et rigide a été proposée très tôt, et de nombreuses études théoriques et expérimentales ont été consacrées à ce phénomène intrigant. Plus récemment, deux marqueurs uniques de la triaxialité dans les noyaux ont été intensivement étudiés : le mouvement d'oscillation de l'axe de rotation (wobbling) et la chiralité dynamique. Ces types exotiques de mouvement ont été observées dans des régions spécifiques du tableau nucléaire : le mouvement d'oscillation dans les noyaux de Lu impair-pair avec A ~ 160, la chiralité principalement dans les noyaux impair-impair et pair-impair avec A ~ 130. Nous avons récemment étudié les noyaux de Nd à très hauts spins et identifié plusieurs bandes, qui ont été interprétées comme la manifestation de divers types de mouvement collectif : rotation suivant un axe incliné, rotation suivant les axes longs et courts, mouvement de wobbling et bandes chirales. Un autre phénomène révélé par nos résultats récents sur les noyaux de Nd avec seulement quelques trous neutroniques par rapport à la fermeture de couche N = 82, est la coexistence de forme. En effet, ces noyaux sont prévus pour avoir des isomères de hauts spins construis sur une forme sphérique, coexistant avec des bandes triaxiales, ou des formes très voire super-déformées . Ma thèse se compose de deux expériences. Tout d'abord, j'ai préparé, exécuté et analysé une expérience réalisée au " Research Center of Nuclear Physics " (RCNP) de l' Université d'Osaka . Cette expérience visait à étudier les isomères de hauts spins et à développer les schémas de niveaux des noyaux de 135La, 136La et 136Ba. Nous avons utilisé un faisceau radioactif de 17N de 80 MeV créé par la réaction directe de 18O sur une cible 9Be et sélectionné à l'aide d'un spectromètre achromatique. Le faisceau radioactif de 17N bombardait une cible de 124Sn de 20 mg/cm2 d'épaisseur pour produire les noyaux d'intérêt par une réaction de fusion-évaporation. Cette thèse présente les résultats obtenus pour le 135La, qui comprennent la construction et la discussion du schéma de niveau et la mesure de la durée de vie de deux isomères connus. La deuxième partie de la thèse consiste en l'analyse de deux expériences différentes réalisée en utilisant la même combinaison de faisceau-cible 48Ca + 96Zr à une énergie légèrement différentes et deux dispositifs expérimentaux différents, EUROBALL et JUROGAM II + RITU + GREAT, pour étudier les isotopes du néodyme de 138Nd à 141Nd. Mon travail a été axé sur les noyaux pair-pair de 138Nd et 140Nd, avec un accent particulier sur le 140Nd. La multitude de bandes de spin élevé observées dans ce noyau sont discutées dans le cadre du modèle " Cranked Nilsson - Strutinsky " (CNS) et du modèle " Tilted Axis Cranking " (TAC). Les bandes de hauts spins observées dans les noyaux de 138-141Nd sont toutes interprétées comme basées sur un minimum d'énergie associé à une déformation triaxiale. Elles représentent donc un fort soutien à l'existence de la forme nucléaire triaxiale stable à hauts spins. L'isomère de haut spin 27- a également été identifié dans le 140Nd qui, combinée avec l'isomère 20+ précédemment connu dans le même noyau va permettre d'extraire pour la première fois une valeur expérimentale de la différence d'énergie entre les orbitales πh11/2 et π(d5/2g7/2) à hauts spins.

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