No description available.

Aufgabe der elektrophysiologischen Studie zur Charakterisierung der neuronalen hypothalamischen Plastizität beim Haushuhn war es, den Einfluss des Alters sowie GABAerger Substanzen auf die Feuerrate und die Temperatursensitivität (thermischer Koeffizient: TC) von Hypothalamusneuronen mittels extrazellulärer Ableitungen in Hirnschnitten zu untersuchen. Im Vergleich zu adulten Vögeln und Säugetieren wurde bei juvenilen Hühnern eine hohe neuronale Kältesensitivität nachgewiesen, die offensichtlich eine spezifische Eigenschaft juveniler Vögel ist. Die Ontogenese der neuronalen hypothalamischen Thermosensitivität ist deutlich artspezifisch. Einige Neurone wiesen eine inherente Kältesensitivität auf. Eine mögliche zentrale Rolle kältesensitiver Neurone im Rahmen der Thermoregulation juveniler Hühner wurde postuliert. Muscimol und Baclofen hemmen signifikant die Feuerrate der Hypothalamusneurone, unabhängig von der jeweiligen Thermosensitivität. Demgegenüber bewirken Bicucullin und CGP35348 einem Anstieg der Feuerrate. Nur bei kältesensitiven Neuronen wurde der TC signifikant durch GABAB-Rezeptor-Liganden verändert (signifikant erhöht durch Baclofen und durch CGP35348 gehemmt). Der Effekt von Muscimol und Baclofen auf Feuerrate und TC wurde durch Co-Perfusion mit einer 10-fach höheren Konzentration der entsprechenden Antagonisten Bicucullin und CGP35348 aufgehoben. Der wesentliche GABAerge Einfluss auf thermosensitive und –insensitive Hypothalamusneurone ist mit dem bei Säugetieren nachgewiesenen vergleichbar. Der einzige Unterschied betrifft die GABAB-Rezeptor vermittelte Änderung des TC. Beim Hühnerküken betraf dies die kältesensitiven und beim Säugetier die wärmesensitiven Neurone. Der grundlegende Mechanismus der GABAergen Beeinflussung thermosensitiver und –insensitiver Neurone scheint einen älteren evolutionären Ursprung zu haben. Eine funktionelle Rolle GABAerger Substanzen im Rahmen der zentralen Kontrolle der Körpertemperatur beim Vogel ist möglich. / In the present electrophysiological studies, characterization of neuronal hypothalamic plasticity in the chicken aims to investigate the influence of age during development by extracellular recordings. High neuronal cold sensitivity has been found in juvenile chicken in contrast to adult mammals and birds. High hypothalamic cold sensitivity seems to be a specific characteristic feature in juvenile birds. Between species a species specificity of the early development of neuronal hypothalamic thermosensitivity could be clearly demonstrated. Existence of inherent nature to a certain degree suggests a possible thermoregulatory role of cold-sensitive neurons in chicken. The effects of the GABAergic substances on neuronal tonic activity (firing rate) and temperature sensitivity (temperature coefficient) in hypothalamic neurons have been examined. Muscimol and baclofen in equimolar concentrations significantly inhibited tonic activity, regardless of their type of thermosensitivity. In contrast bicuculline and CGP 35348 increased firing rate. Temperature coefficient was significantly changed by ligands of GABAB receptors, restricted to cold-sensitive neurons. The TC was significantly increased by baclofen and significantly decreased by CGP 35348. Effects of muscimol and baclofen on firing rate and TC were prevented by co-perfusion of appropriate antagonists bicuculline and CGP 35348, respectively in tenfold higher concentration. Thus the main effects of GABA in chicken are similar with that described in mammals. The only difference is in respect of the GABAB receptors mediated change restricted to cold-sensitive neurons in chicken but in mammals only seen in warm-sensitive neurons. However, the results indicate that the fundamental mechanism of GABAergic influence in chicken are conserved during evolution. The response of hypothalamic neurons to temperature changes suggest a possible functional role of GABAergic substances in the control of body temperature in birds.

Das posttraumatische Hirnödem trägt zur erhöhten Morbidität und Mortalität Schädel-Hirn-traumatisierter Patienten bei. Das vasodilatierende Bradykinin führt als ein Bestandteil des Kallikrein-Kinin-Systems über Bradykinin-2 (B2)-Rezeptoren zu einer Öffnung der Blut-Hirn-Schranke und trägt damit zur Entstehung und Aufrechterhaltung des vasogenen bzw. zytotoxischen Hirnödems bei. Eine selektive Hemmung der B2-Rezeptoren konnte bereits die Ausbreitung des posttraumatischen vasogenen Hirnödems erfolgreich vermindern. Im ersten Teil der vorliegenden Arbeit wurde zunächst die Entwicklung des vasogenen Hirnödems, der hemisphäralen Schwellung und der Integrität der Blut-Hirn-Schranke im zeitlichen Verlauf bis 7 Tage nach Controlled Cortical Impact Injury (CCII) an Ratten anhand T2- und T1-gewichteter MRT-Bildgebung charakterisiert. Im zweiten Teil wurde eine mögliche therapeutische Wirkung des spezifischen B2-Antagonisten LF 16.0687 Ms auf das posttraumatische Ödem und der Blut-Hirn-Schrankenöffnung durch Anwendung von MRT- und gravimetrischer Methoden untersucht. In den T2-gewichteten Sequenzen kam es innerhalb von 90 Minuten nach CCII zum prozentual stärksten Anstieg der hemisphäralen Schwellung, ein Maximum lag zwischen 24 und 48 Stunden vor gefolgt von einer Abnahme bis 7 Tage danach. T1-gewichtete Aufnahmen zeigten ein durch die Extravasation von Gadolinium-DTPA erzeugtes Maximum der Kontrastverstärkung innerhalb des Läsionszentrums bereits 6 Stunden nach CCII, während die Kontrastverstärkung in der Ödemperipherie erst nach 48 Stunden Maximalwerte erreichte. Bei einer frühzeitigen Gabe des Kontrastmittels 90 Minuten nach CCII kam es im Verlauf zu einer signifikant höheren Kontrastverstärkung innerhalb der traumatisierten Hemisphäre, vermutlich durch eine Retention des extravasierten Kontrastmittels. Dies könnte für eine frühe Restitution der Blut-Hirn-Schranken Integrität innerhalb der Kontusion sprechen, während der Verschluß perikontusionell erst später erfolgt. LF 16.0687 Ms führte bei frühzeitiger Gabe nach CCII zu einer signifikanten Reduktion der gravimetrisch bestimmten posttraumatischen hemisphäralen Schwellung um 27%. Hierbei korrelierte die im MRT ermittelte hemisphärale Schwellung signifkant mit den gravimetrisch gemessenen Werten. / Posttraumatic brain edema contributes to a higher morbidity and mortality in severe head-injured patients. Vasodilatating bradykinin, part of the kallikrein-kinin-system, mediates over bradykinin 2 (B2) receptors an blood-brain-barrier (BBB) disfunction and causes the formation and maintenance of vasogenic and cytotoxic brain edema. A selective blocking of the B2 receptors has been shown to successfully reduce brain edema formation. One objective of this study was to analize the development of vasogenic brain edema, lesion-size, hemispheric swelling and BBB-integrity after controlled cortical impact injury (CCII) in rats over a period of 7 days using magnetic resonance imaging (MRI) techniques (T2- and T1-weighted MRI, Gadolinium-DTPA (Gd-DTPA)). The other purpose was to investigate the protective effect of the novel nonpeptide B2 receptor antagonist LF 16-0687 Ms on posttraumatic edema and BBB-opening using MRI- and gravimetric methods. T2-weighted imaging showed the highest percentual increase of hemispheric swelling during the first 90 minutes after CCII, a maximum between 24 and 48 hours after CCII and and a decrease after 7 days. T1-weighted imaging revealed a maximum of contrast enhancement caused by extravasation of Gd-DTPA in the lesion-center 6 hours after CCII, while contrast enhancement in the lesion periphery reached its maximum at 48 hours.After an early administration of Gd-DTPA (90 minutes after CCII) contrast enhancement in the traumatized hemisphere was significantly higher compared to the non-traumatized hemisphere. This could be explained by a retention of Gd-DTPA caused by an early closure of the BBB in the lesion-center, while BBB-integrity in the lesion-periphery re-establishes later. The novel nonpeptide B2 receptor antagonist LF 16-0687Ms significantly reduced brain swelling by 27% after single administration measured by gravimetric wet-dry-weighting. Gravimetric and T2-weighted MRI-measurements of hemispheric swelling correlated significantly.

Objetivos: Avaliar a utilidade dos mediadores pró-inflamatórios (TNF-alfa, IL-1 beta e IL-6), dos mediadores antiinflamatórios (IL-10 e IL-1Ra) e da Proteína C reativa (PCR) para o diagnóstico na sepse neonatal; verificar se os valores séricos isolados ou a relação entre IL-6 e IL-1Ra têm valor preditivo de gravidade, na evolução clínica da doença; determinar se a homeostase entre os mediadores pró-inflamatórios e antiinflamatórios e a PCR definem o prognóstico da doença. Casuística e métodos: Foram incluídos no estudo 31 recém-nascidos (RN) internados na UCINE ou no Hospital Universitário com diagnóstico de sepse, baseado em critérios clínicos e laboratoriais. Os RN com diagnóstico de sepse foram subdivididos em dois grupos de acordo com a evolução clínica: grupo sepse: os que tiveram boa evolução e grupo sepse grave, os que tiveram evolução complicada por choque séptico e/ou CIVD e/ou FMOS e/ou óbito. Além dos exames de rotina para sepse, forma mensurados nos dias 0, 3 e 7 de evolução a partir do diagnóstico, os níveis séricos de TNF-alfa, IL-1 beta, IL-6, IL-10 e IL-1Ra. Resultados: Na análise evolutiva geral, todos os mediadores inflamatórios apresentaram mensuração elevada no dia do diagnóstico (dia 0), com decréscimo dos valores no decorrer do tempo. Entre os mediadores pró-inflamatórios, a TNF-alfa, a IL-6 e a IL-1 beta se mostraram adequados para o diagnóstico, no entanto para o seguimento, a melhor foi a IL-6. Entre os mediadores antiinflamatórios a IL-10 seguiu os padrões dos mediadores próinflamatórios acompanhando a resolução do processo séptico, enquanto a IL-1Ra apresentou decréscimos até o 3º dia e permaneceu estável até o 7º dia caracterizando a perpetuação da ação antiinflamatória desta citocina. Quanto às relações entre mediadores pró-inflamatórios e antiinflamatórios (relação IL-6/IL-1Ra e IL-6/(IL-6 + IL-1Ra) observamos que a IL-6/IL-1Ra apresentou relação com a evolução do processo séptico, mostrando inicialmente predomínio da ação próinflamatória no dia 0 e antiinflamatória no dia 7. A PCR acompanhou de forma muito semelhante as curvas da TNF-alfa, L-6 e IL-10. Quando se subdividiu a casuística em grupos, sepse e sepse grave, observamos que os RN com sepse com boa evolução apresentaram níveis séricos médios de TNF-alfa, IL-1 beta e IL-10 próximos aos níveis mínimos detectáveis e estas citocinas nos RN com sepse grave. / Objectives - To evaluate the utility of the pro-inflammatory mediators (TNF-alfa, IL1-beta, and IL-6), the anti-inflammatory mediators (IL-10 and IL-1Ra) and C-Reactive Protein (CRP) for the diagnosis of neonatal sepsis; to verify whether the isolated seric values or the relation between IL-6 and IL-1Ra have predictive values for severity regarding the clinical outcome, and to ascertain if the homeostasis between the pro-inflammatory and anti-inflammatory mediators and CPR can define the prognosis of the disease. Patients and Methods - The study included 31 newborns (NB) admitted to the UCINE (External Neonatal Unit) or to Hospital Universitário (São Paulo University Hospital) with diagnosis of sepsis based upon clinical and laboratorial parameters. The NB with diagnosis of sepsis were further subdivided into 2 groups according to the clinical outcome: sepsis group: containing those NB who evolved to a positive outcome, and severe sepsis group, in turn composed of the NB with unsatisfactory outcomes due to complications caused by septic shock and/or DIVC and/or FMOS and/or death. On days 0, 3, and 7 following diagnosis the seric levels of TNF-alfa, IL-1 beta, IL-6, IL-10, and IL-1Ra were measured in addition to the routine sepsis workup. Results - The general follow-up analysis revealed that all the inflammatory mediators presented elevated levels at diagnosis (day 0) with a decrease of these values over time. Regarding the pro-inflammatory mediators, TNF-alfa, IL-6 and IL-1 beta were satisfactory for diagnosis, whereas IL-6 was more accurate for follow-up. In relation to the anti-inflammatory mediators, IL-10 revealed the same pattern of the pro-inflammatory mediators following the septic process resolution, whereas IL-1Ra gradually decreased until the 3rd day but hence remained stable until the 7th day, thus characterizing the continuity of the anti-inflammatory action of this cytokine. Concerning the inter-relation between the pro and anti-inflammatory mediators (IL-6/IL-1Ra relation and IL-6/(IL6+IL-1Ra)) we observed that the IL-6/IL-1Ra correlated with the septic process evolution with predominance of the proinflammatory action on day 0 and of the anti-inflammatory action on day 7. The CRP levels, we observed that in the sepsis group with satisfactory outcome on day 0 the seric values were higher than in the severe sepsis group, although on days 3 and 7 these values decreased more substantially, while in the sepsis group they increased on day 3 followed by a gradual decrease until day 7. Conclusions - The analyzed mediators were effective in the diagnosis of neonatal sepsis and also predictive of the degree of severity, mainly with regards to cytokines IL-6 and IL-1Ra. The homeostatic equilibrium/disequilibrium was correlated to the type of disease outcome: sepsis with no complications versus severe sepsis.

Objetivos: Avaliar a utilidade dos mediadores pró-inflamatórios (TNF-alfa, IL-1 beta e IL-6), dos mediadores antiinflamatórios (IL-10 e IL-1Ra) e da Proteína C reativa (PCR) para o diagnóstico na sepse neonatal; verificar se os valores séricos isolados ou a relação entre IL-6 e IL-1Ra têm valor preditivo de gravidade, na evolução clínica da doença; determinar se a homeostase entre os mediadores pró-inflamatórios e antiinflamatórios e a PCR definem o prognóstico da doença. Casuística e métodos: Foram incluídos no estudo 31 recém-nascidos (RN) internados na UCINE ou no Hospital Universitário com diagnóstico de sepse, baseado em critérios clínicos e laboratoriais. Os RN com diagnóstico de sepse foram subdivididos em dois grupos de acordo com a evolução clínica: grupo sepse: os que tiveram boa evolução e grupo sepse grave, os que tiveram evolução complicada por choque séptico e/ou CIVD e/ou FMOS e/ou óbito. Além dos exames de rotina para sepse, forma mensurados nos dias 0, 3 e 7 de evolução a partir do diagnóstico, os níveis séricos de TNF-alfa, IL-1 beta, IL-6, IL-10 e IL-1Ra. Resultados: Na análise evolutiva geral, todos os mediadores inflamatórios apresentaram mensuração elevada no dia do diagnóstico (dia 0), com decréscimo dos valores no decorrer do tempo. Entre os mediadores pró-inflamatórios, a TNF-alfa, a IL-6 e a IL-1 beta se mostraram adequados para o diagnóstico, no entanto para o seguimento, a melhor foi a IL-6. Entre os mediadores antiinflamatórios a IL-10 seguiu os padrões dos mediadores próinflamatórios acompanhando a resolução do processo séptico, enquanto a IL-1Ra apresentou decréscimos até o 3º dia e permaneceu estável até o 7º dia caracterizando a perpetuação da ação antiinflamatória desta citocina. Quanto às relações entre mediadores pró-inflamatórios e antiinflamatórios (relação IL-6/IL-1Ra e IL-6/(IL-6 + IL-1Ra) observamos que a IL-6/IL-1Ra apresentou relação com a evolução do processo séptico, mostrando inicialmente predomínio da ação próinflamatória no dia 0 e antiinflamatória no dia 7. A PCR acompanhou de forma muito semelhante as curvas da TNF-alfa, L-6 e IL-10. Quando se subdividiu a casuística em grupos, sepse e sepse grave, observamos que os RN com sepse com boa evolução apresentaram níveis séricos médios de TNF-alfa, IL-1 beta e IL-10 próximos aos níveis mínimos detectáveis e estas citocinas nos RN com sepse grave. / Objectives - To evaluate the utility of the pro-inflammatory mediators (TNF-alfa, IL1-beta, and IL-6), the anti-inflammatory mediators (IL-10 and IL-1Ra) and C-Reactive Protein (CRP) for the diagnosis of neonatal sepsis; to verify whether the isolated seric values or the relation between IL-6 and IL-1Ra have predictive values for severity regarding the clinical outcome, and to ascertain if the homeostasis between the pro-inflammatory and anti-inflammatory mediators and CPR can define the prognosis of the disease. Patients and Methods - The study included 31 newborns (NB) admitted to the UCINE (External Neonatal Unit) or to Hospital Universitário (São Paulo University Hospital) with diagnosis of sepsis based upon clinical and laboratorial parameters. The NB with diagnosis of sepsis were further subdivided into 2 groups according to the clinical outcome: sepsis group: containing those NB who evolved to a positive outcome, and severe sepsis group, in turn composed of the NB with unsatisfactory outcomes due to complications caused by septic shock and/or DIVC and/or FMOS and/or death. On days 0, 3, and 7 following diagnosis the seric levels of TNF-alfa, IL-1 beta, IL-6, IL-10, and IL-1Ra were measured in addition to the routine sepsis workup. Results - The general follow-up analysis revealed that all the inflammatory mediators presented elevated levels at diagnosis (day 0) with a decrease of these values over time. Regarding the pro-inflammatory mediators, TNF-alfa, IL-6 and IL-1 beta were satisfactory for diagnosis, whereas IL-6 was more accurate for follow-up. In relation to the anti-inflammatory mediators, IL-10 revealed the same pattern of the pro-inflammatory mediators following the septic process resolution, whereas IL-1Ra gradually decreased until the 3rd day but hence remained stable until the 7th day, thus characterizing the continuity of the anti-inflammatory action of this cytokine. Concerning the inter-relation between the pro and anti-inflammatory mediators (IL-6/IL-1Ra relation and IL-6/(IL6+IL-1Ra)) we observed that the IL-6/IL-1Ra correlated with the septic process evolution with predominance of the proinflammatory action on day 0 and of the anti-inflammatory action on day 7. The CRP levels, we observed that in the sepsis group with satisfactory outcome on day 0 the seric values were higher than in the severe sepsis group, although on days 3 and 7 these values decreased more substantially, while in the sepsis group they increased on day 3 followed by a gradual decrease until day 7. Conclusions - The analyzed mediators were effective in the diagnosis of neonatal sepsis and also predictive of the degree of severity, mainly with regards to cytokines IL-6 and IL-1Ra. The homeostatic equilibrium/disequilibrium was correlated to the type of disease outcome: sepsis with no complications versus severe sepsis.

本研究以心理興奮性藥物(psychosimulants)引發之行為致敏化作為探討環境與藥物的配對學習如何影響個體長期使用藥物後對藥物的反應。首先於實驗一建立安非他命引發自發活動致敏化基本模式，以及不同的重複注射情境下致敏化的表現，結果顯示經由本實驗操弄注射情境的程序可有效引發在測試箱、飼養籠，和第三處的安非他命致敏化表現，並且致敏化自發活動表現量在測試箱組顯著高於飼養籠組和第三處組。實驗二對致敏化形成歷程中可能與安非他命配對的刺激進行消除，以釐清致敏化形成歷程中連結學習的要素，結果顯示消除程序沒有降低致敏化活動量的效果。實驗三使用中樞注射麩胺酸受體拮抗劑NBQX於依核以影響致敏化的連結學習歷程，結果顯示該操弄可阻斷在飼養籠重複注射安非他命引發的行為致敏化。測試箱組經過該操弄後其致敏化活動量顯著降低但仍有顯著的致敏化活動量表現。實驗四分別破壞前額葉皮質兩處次級區塊以瞭解其在致敏化連結學習歷程中扮演的角色，結果顯示破壞背側前額葉皮質只阻斷在飼養籠注射安非他命所引起的行為致敏化，破壞腹側前額葉皮質只阻斷測試箱組行為致敏化。綜合上述研究結果顯示安非他命引發致敏化的形成深受藥物配對的環境影響而可區分環境相依與環境獨立之行為致敏化，環境相依行為致敏化的行為機制可由場合建立的觀點加以解釋。在依核內之麩胺酸傳導和前額葉皮質次級區塊之功能在兩種行為致敏化上的差異可以反應環境相依和環境獨立行為致敏化的潛在神經機制可能有所不同。 / The present study investigated the neurobehavioral mechanisms of d-amphetamine (AMP) induced behavioral sensitization, with the aim to elucidate the role of associative learning between the context and drug. Experiment 1 compared the sensitization effects of repeated (AMP) conducted in three different contexts by the measurement of locomotion activity. The results showed that behavioral sensitization of locomotion was significantly induced AMP repeatedly injected in each of the contexts. However, the magnitudes of behavioral sensitization were different among those three conditions. The highest degree of sensitized locomotion was observed in the group with repeated AMP conducted in the test box in comparing to the other two groups with drug administration in the home cage and a third place, Experiment 2 was designed to examine the effects of extinction on the injection procedure and the contextual cue on the behavioral sensitization of AMP induced in the test box, the home cage, and a third place. The resu lts clearly indicate all three types of locomotion sensitization were resistant to the manipulation of extinction. Experiment 3 tested the effects of NBQX, a glutamatergic AMPA receptor antagonist, infused into the nucleus accumbens on the establishment of behavioral sensitization of AMP induced in the test box and the home cage. This intra-accumbens NBQX treatment significantly suppressed the formation of behavioral sensitization of AMP induced in the home cage, but not in the test box. Experiment 4 investigated the lesion effects of medial prefrontal cortex (mPFC) on the establishment of behavioral sensitization of AMP induced in the test box and the home cage. Two subareas of the mPFC, dorsal and ventral parts, were lesioned by ibotenic acid. The findings indicated a double dissociation existing in the mPFC subareas for the behavioral sensitization of AMP induced in different contexts. The lesion of ventral mPFC inhibited the formation of behavioral sensitization of AMP induced in the test box, whereas the lesion of dorsal mPFC attenuated the AMP sensitization induced at the home cage. Together, these data suggest that the association of the repeated drug effects pairing to the context is critical for the development of behavioral sensitization. Such sensitization can further be differentiated into the context-depentdent and context-independent forms based on the uniqueness of contextual cue in the environment where drug is administered. Different neural substrates are involved in the establishment of behavioral sensitization of AMP.

No description available.

No description available.

La néphropathie aux plantes chinoises (CHN) est une maladie rénale grave qui a été décrite pour la première fois en 1993 chez des patientes ayant suivi un régime amaigrissant à base d’extraits de plantes chinoises (Aristolochia fangchi) contenant des acides aristolochiques (AA). Cette néphropathie se caractérise par une atrophie tubulaire et une fibrose interstitielle aboutissant à l’urémie terminale et se complique fréquemment de cancers des voies urinaires. Au moment d’initier ce travail, il subsistait toujours un large débat quant au rôle étiologique réel des acides aristolochiques dans la genèse de cette maladie. En effet, les gélules à visée amaigrissante contenaient d’autres substances potentiellement néphrotoxiques. Mais surtout, il n’existait aucune preuve expérimentale que les AA pouvaient induire une fibrose rénale interstitielle.<p>Dans la première partie de ce travail, nous démontrons que l’injection par voie sous-cutanée d’AA à la dose de 10 mg/Kg/jour à des rats Wistar mâles en déplétion sodée entraîne l’apparition au 35ème jour d’une atrophie tubulaire, d’une fibrose interstitielle et d’une insuffisance rénale, reproduisant ainsi les anomalies caractéristiques de la CHN. Nous avons ensuite montré que la dexfenfluramine, substance anorexigène à action de type sérotoninergique prise concomitamment par les patientes atteintes de CHN, ne potentialise pas la toxicité rénale des AA. Enfin, la stimulation du système rénine angiotensine (SRA) par la déplétion sodée ou l’inhibition de celui-ci par un traitement pharmacologique ne modifie pas la fibrose interstitielle ni l’insuffisance rénale induite par les AA.<p>En conclusion, nous avons réussi à développer un modèle in vivo de fibrose rénale interstitielle induite par les AA. Dès lors nous avons apporté la preuve expérimentale de l’implication des AA dans le développement de la CHN. Ce modèle a permis de démontrer que les autres éléments potentiellement néphrotoxiques contenues dans la cure d’amaigrissement (dexfenfluramine, diurétique, laxatif) n’influençaient pas l’évolution de la fibrose interstitielle, ce qui confirme que la prise isolée d’AA suffit à expliquer le développement de la CHN. Cette confirmation à d’importantes implications en santé publique dans la mesure où des plantes contenant des acides aristolochiques font toujours partie des phytothérapies traditionnelles. De plus, il est apparu que, dans ce modèle, les mécanismes de la fibrose rénale interstitielle pouvaient être largement indépendants du SRA. Enfin, de par sa durée limitée et sa grande reproductibilité, ce modèle constitue un outil expérimental d’avenir pour l’étude des mécanismes physiopathologiques de la fibrose rénale interstitielle en général.<p> / Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished

Acute spinal cord injury is often caused by collisions with motor vehicles, falls or violence. This injury could potentially lead to paraplegia or tetraplegia, causing great economic and personal loss. The patophysiology is biphasic, with primary and secondary mechanisms. Regarding secondary spinal cord injury, glutamate and interleukin-1 beta (IL-1<img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Cbeta" data-classname="equation" data-title="" />) activates N-methyl-d-aspartate (NMDA)-receptors leading to prolonged excitotoxity, causing neuronal death and subsequently glial scarring. Cross-linked-hyaluronic acid gel and interleukin-1 receptor antagonist (IL-1RA) are believed to have a neuroprotective effect. The major aim of this study was to evaluate neuroprotection in the central neural system. Briefly, spinal cord slice cultures from mice (p9-12) were chemically injured with NMDA and treated with two hyaluronic acid-based gels with integrated, or added, IL1RA. RNA was extracted and transcripted to cDNA. The gene expression of Neuronal nuclear protein, <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Cbeta" data-classname="equation" data-title="" />-aktin and IL-1<img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Cbeta" data-classname="equation" data-title="" /> were studies with RT-qPCR. Results showed that gel integrated with IL1RA had significant therapeutic effect, resembling undamaged cultures. Furthermore, axonal outgrowth was investigated in dorsal root ganglion (DRG) in which two preparations of the method were evaluated. Results demonstrated that changing medium every other day was more preferred, compared to adding 20 µl medium every day.  In conclusion, gels integrated with IL1RA have neuroprotective properties and in DRG preparations, medium should be changed every other day for optimal results.