The objectives of this study were to determine the cardiopulmonary effects and pharmacokinetics of fentanyl in dogs during isoflurane anesthesia and during anesthetic recovery with or without dexmedetomidine or acepromazine sedation. This was investigated in 7 healthy dogs using a randomized cross over study design. Dogs were given fentanyl as an initial IV loading dose (5 μg/kg) followed by an infusion (5 μg/kg/hr) for 120 minutes during isoflurane anesthesia and for 60 minutes following isoflurane discontinuation. Dogs received IV dexmedetomidine (2.5 μg/kg), acepromazine (0.05 mg/kg) or saline at the time of isoflurane discontinuation. Cardiopulmonary variables were measured and blood samples were obtained at multiple time points during the anesthetic maintenance and recovery phases. Plasma concentrations of fentanyl were measured using HPLC-MS, and subsequent population pharmacokinetic analysis was performed. During isoflurane anesthesia, fentanyl bolus administration resulted in significant changes in measured cardiopulmonary variables, however, many returned to baseline values during the maintenance of anesthesia. During anesthetic recovery, dexmedetomidine administration resulted in significant increases in PaCO2, and decreases in PvO2 and CI. Systemic arterial blood pressures were significantly lower in dogs receiving acepromazine, however CI and PvO2 were significantly higher compared to the other treatments. Analysis of fentanyl plasma concentrations showed that fentanyl pharmacokinetics best fit a 2-compartmental model, with average concentrations in the treatment groups ranging from 1.6 to 4.5 ng/mL during isoflurane anesthesia, and from 1.6 to 2.0 ng/mL during anesthetic recovery. Plasma concentrations of fentanyl were significantly higher with dexmedetomidine administration compared to the other treatments during the recovery period. Compared to the maintenance phase of anesthesia, anesthetic recovery with dexmedetomidine administration did not significantly change fentanyl pharmacokinetics, while acepromazine administration increased systemic and intercompartmental clearance, and recovery without sedation increased the central volume of distribution and systemic clearance. In conclusion, recovery from anesthesia with concurrent fentanyl administration, with or without sedation, caused clinically significant alterations in cardiopulmonary function that influenced fentanyl disposition in healthy dogs. / Ontario Veterinary College Pet Trust Fund

A clinical trial was undertaken using three different inhalant anaesthetic agents and one intravenous anaesthetic agent in dogs undergoing routine desexing surgery. Healthy adult dogs undergoing either ovariohysterectomy or castration were assessed as to their demeanour, with the more excitable dogs being placed in groups receiving premedication with acepromazine and morphine. All dogs were then randomly assigned an anaesthetic agent for induction of general anaesthesia. The agents were the inhalants halothane, isoflurane and sevoflurane, and the intravenous agent propofol. Inhalant inductions were undertaken using a tight fitting mask attached to a standard anaesthetic machine with a rebreathing circuit, with the maximum dose of inhalant available from a standard vaporiser. Propofol inductions were undertaken via intravenous catheter. Dogs induced with propofol were randomly assigned one of the three inhalant agents for maintenance. Those induced by inhalant agent were maintained using the same agent. The surgical procedure was undertaken in standard fashion, as was recovery from anaesthesia. All dogs received the non-steroidal anti-inflammatory agent meloxicam. Data collection was divided into three stages: induction, maintenance, and recovery from anaesthesia. Variables measured at induction of anaesthesia were time to intubation, number of intubation attempts, tolerance of mask, quality of induction and quality of transfer to the maintenance stage. Standard variables for monitoring of anaesthesia were recorded throughout the maintenance of anaesthesia. Variables measured at recovery were time to righting, time to standing and quality of recovery. The mean time to intubation when using the newer inhalant sevoflurane (196.2 � 14.8sec, mean � SE) was not significantly different to that for halothane (221.4 � 14.0sec) or isoflurane (172.4 � 15.0sec). Time to intubation with isoflurane was significantly faster than with halothane. Mean time to intubation with propofol (85.4 � 7.7sec) was significantly faster than that for any of the three inhalants. Choice of inhalant had no effect on quality of induction. The use of premedication significantly improved the quality of induction. The use of propofol for induction likewise significantly improved the quality of induction. Standard cardiorespiratory variables measured during the maintenance phase of anaesthesia remained within normal clinical ranges for all three inhalants, and were therefore not further analysed. Choice of inhalant agent had no significant effect on the time to righting or standing in recovery. The use of propofol for induction had no effect on these variables. Animals placed in groups receiving premedication had significantly longer times to righting and standing. The oesophageal temperature at the end of the procedure had a significant effect on times to righting and standing, with lower temperatures contributing to slower recoveries. Independent of procedure time, male dogs had shorter times to righting than female dogs.

Orientador: Pedro Thadeu Galvão Vianna / Banca: Yara Marcondes Machado Castiglia / Banca: Eliana Marisa Ganem / Banca: Alexandra Rezende Assad / Banca: Anita Leocádia de Mattos / Resumo: A hiperglicemia aumenta a lesão renal na isquemiareperfusão em ratos anestesiados com isoflurano (Iso). Este efeito é desconhecido com o uso do propofol (Prop). O objetivo desse estudo é avaliar o efeito do isoflurano (Iso) e do propofol na lesão renal de isquemia-reperfusão na presença de hiperglicemia transitória.Utilizou-se 36 ratos Wistar machos, distribuídos de modo aleatório em seis grupos de seis animais, designados: PHS (Prop + Hiperglicemia - Sham); IHS (Iso + Hiperglicemia - Sham); PHI (Prop + Hiperglicemia + Isquemia); IHI (Iso + Hiperglicemia + Isquemia); PI (Prop + Isquemia) e II (Iso + Isquemia). A anestesia foi mantida com isoflurano (1,5 a 2%) (IHS, IHI e II) ou propofol (1 mg.kg-1.min-1) (PHS, PHI e PI). A pressão arterial média (PAM) foi medida para o controle da anestesia. A hiperglicemia foi induzida com a injeção de 2,5 g.kg-1 de solução de glicose por via intraperitoneal. Todos os animais foram submetidos à nefrectomia direita. Os dois grupos "sham" foram submetidos à hiperglicemia. Os demais grupos foram submetidos à isquemia renal por 25 minutos. Os valores plasmáticos da glicose e da creatinina foram determinados no início (M1), no final do experimento (M2) e 24 horas após o final do experimento (M3), quando os animais retornaram ao laboratório e foram anestesiados com isoflurano para coleta de uma nova amostra sanguínea e nefrectomia esquerda, para análise histológica, com o uso de uma escala para avaliação da necrose tubular (0 a 5 = lesão máxima), e avaliação por citometria de fluxo, para determinação dos percentuais da apoptose inicial (APTi) e de células viáveis (VC). Houve tratamento estatístico para os valores da PAM, glicose e creatinina plasmáticas escore de lesão histológica e avaliação da citometria de fluxo,sendo as diferenças consideradas significantes quando <0,05.A glicemia (mg.dL-1) em M2 foi maior nos grupos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The hyperglycemia augments the renal ischemic-reperfusion injury (IRI) in rats anesthetized with isoflurane (Iso). This effect with propofol (Prop) is unknown. The purpose of this investigation was to examine the effect of isoflurane and propofol in renal ischemia/reperfusion injury (IRI) during transient hyperglycemia.Rats were randomly assigned in six groups of six animals, groups: PHS (Prop + Hyperglycemia - Sham); IHS (Iso + Hyperglycemia - Sham); PHI (Prop + Hyperglycemia + Ischemia); IHI (Iso + Hyperglycemia + Ischemia); PI (Prop + Ischemia) and II (Iso + Ischemia). Propofol in a dose of 1 mg.kg-1.min-1 (PHS, PHI and PI) or saline was infused (IHS, IHI and II). Mean arterial pressure (MAP) was monitored for anesthesia control. Hyperglycemia was induced with the injection of 2.5 g.kg-1 of glucose solution. All animals underwent to right nephrectomy. The two sham groups underwent to hyperglycemia with ischemia. The others groups were submitted to a left renal ischemia for 25 minutes. Serum creatinine and glucose values were determined in the beginning (M1) and at the end of experiment (M2) and 24 hours after the experiment (M3) rats were anesthetized with isoflurane and blood sample was collected and the left kidney removed for histological analysis, using a scale for tubular necrosis (0-5 = injury maximum). In addition to a histological study, cells from the left kidney were evaluated for apoptosis by flow cytometry (FCM) as a % of initial apoptosis (APTi) and viable cell (VC). Statistical analysis were applied to the values of MAP, serum creatinine and glucose, histological score injury and FCM and statistical differences were considered when p<0.05.Serum glucose at M2 was higher in PHS (351.8±141.0) and IHI (348.3±52.3) in relation to groups PI (147.0±62.4) and II (162.7±40.2). Groups IHS (302.5±80.0) and PHI (308.5±74.5) showedintermediary values. Serum creatinine... (Complete abstract click electronic access below) / Doutor

Orientador: Antonio José Araújo Aguiar / Banca: Suzane Lilian Beier / Banca: Stelio Pacca Loureiro Luna / Resumo: Opioides reduzem a CAM de agentes inalatórios em diversas espécies. O objetivo do presente estudo foi avaliar o efeito de três doses de sufentanil ,administradas em infusão contínua, na CAMiso em felinos. Oito gatos adultos e castrados (4.0±0.5 kg-1) foram anestesiados com isofluorano em três ocasiões distintas com um intervalo mínimo de sete dias mantidos em ventilação mecânica. A temperatura esofágica foi mantida na faixa de 38.5 a 39.0°C. Uma das três doses de sufentanil (0.01; 0.025 e 0.05 μg kg-1 minuto-1) foi selecionada aleatoriamente e infundida em cada experimento. A CAMiso basal individual, a CAMiso durante a infusões e a CAMiso após uma hora do término da infusão foram determinadas em todos os experimentos. As infusões eram feitas por 60 minutos antes da determinação da CAMISO em cada dose de sufentanil. As determinações da CAMISO foram realizadas de modo duplicado usando estímulo elétrico (50 V, frequência 50, 10 ms) aplicados nos antebraço. FC, PAS, PAM, PAD, EtCO2 e análise hemogasométrica eram registrados antes de cada determinação da CAMiso. Dados (média ± SD) foram analisados por ANOVA seguido do teste de Tukey (p<0.05%). Os valores de CAMbasal não diferiram estatisticamente (1.64±0.13; 1.61±0.24 e 1.62±0.31%). As infusões de sufentanil (0.01; 0.025 e 0.05 μg μg kg-1 minuto-1) reduziram significativamente a CAMISO 21.4±10.8; 18.5±10.5 e 18.0±13.7%, respectivamente. Não houve diferença significativa entre os valores de CAMISO durante as infusões.Os valores de CAMISO controle (1.56±0.26; 1.50±0.22 e 1.53±0.26%) foram inferiores da CAMISO basal indicando um possível efeito residual do opioide após a descontinuação da infusão. Os valores de FC e das pressões arteriais aumentaram durante as infusões de sufentanil 0.025 e 0.05 μg kg-1 minuto-1. As três doses de sufentanil infundidas resultaram em graus semelhantes... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Opioids reduce the MAC of Inhalants agents in many species. The aim of this study was to evaluate the effects of three sufentanil constant rate infusions (CRIs) on the MACISO in cats. Eight adult spayed cats (4.0±0.5 kg-1) were anesthetized with isoflurane under mechanical ventilation on three occasions with a minimum 7-day interval between. Esophageal temperature was maintained within a narrow range (38.5 to 39.0°C). One of three sufentanil CRIs (0.01; 0.025 and 0.05 μg kg-1 minute-1) was randomly selected to be administered on each day of MACISO determinations. On all study days, the individual basal MACISO (MACbasal), the MACISO during one of the infusion rates, and the control one hour post-infusion MAC (MACcontrol) were determined. CRI was continued for 60 minutes before MACISO was determined for each sufentanil dose. The MACISO determinations were performed in duplicate using an electrical stimulus (50V, 50 cycles second-1, 10 ms) applied to the antebrachium. HR, SAP, MAP, DAP, ETCO2, and arterial blood gases were recorded before and after each MACISO determination. Data (mean±SD) were compared by ANOVA followed by Tukey's test (p<0.05%).MACbasal values were not significantly different (1.64±0.13; 1.61±0.24 and 1.62±0.31%). Sufentanil CRIs (0.01; 0.025 and 0.05 μg kg-1 minute-1) significantly reduced MACISO by 21.4±10.8; 18.5±10.5 and 18.0±13.7%, respectively. There were no significant differences between the MACISO values determined during the CRIs. The MACcontroll values (1.56±0.26; 1.50±0.22 and 1.53±0.26%) were different from MACbasal indicating the possibility of a residual opioid effect after the discontinuation of infusions. HR and blood pressure values increased during infusion of the higher sufentanil CRIs (0.025 and 0.05 μg kg-1 minute-1). The three CRI doses of sufentanil resulted in similar degrees of MACISO reduction in cats, indicating that... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-06-11T19:35:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-24Bitstream added on 2014-06-13T19:05:31Z : No. of bitstreams: 1 carraretto_ar_dr_botfm.pdf: 822756 bytes, checksum: d39d7bb3ab7eed1fb356cccaf87705ec (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A hiperglicemia aumenta a lesão renal na isquemiareperfusão em ratos anestesiados com isoflurano (Iso). Este efeito é desconhecido com o uso do propofol (Prop). O objetivo desse estudo é avaliar o efeito do isoflurano (Iso) e do propofol na lesão renal de isquemia-reperfusão na presença de hiperglicemia transitória.Utilizou-se 36 ratos Wistar machos, distribuídos de modo aleatório em seis grupos de seis animais, designados: PHS (Prop + Hiperglicemia - Sham); IHS (Iso + Hiperglicemia - Sham); PHI (Prop + Hiperglicemia + Isquemia); IHI (Iso + Hiperglicemia + Isquemia); PI (Prop + Isquemia) e II (Iso + Isquemia). A anestesia foi mantida com isoflurano (1,5 a 2%) (IHS, IHI e II) ou propofol (1 mg.kg-1.min-1) (PHS, PHI e PI). A pressão arterial média (PAM) foi medida para o controle da anestesia. A hiperglicemia foi induzida com a injeção de 2,5 g.kg-1 de solução de glicose por via intraperitoneal. Todos os animais foram submetidos à nefrectomia direita. Os dois grupos “sham” foram submetidos à hiperglicemia. Os demais grupos foram submetidos à isquemia renal por 25 minutos. Os valores plasmáticos da glicose e da creatinina foram determinados no início (M1), no final do experimento (M2) e 24 horas após o final do experimento (M3), quando os animais retornaram ao laboratório e foram anestesiados com isoflurano para coleta de uma nova amostra sanguínea e nefrectomia esquerda, para análise histológica, com o uso de uma escala para avaliação da necrose tubular (0 a 5 = lesão máxima), e avaliação por citometria de fluxo, para determinação dos percentuais da apoptose inicial (APTi) e de células viáveis (VC). Houve tratamento estatístico para os valores da PAM, glicose e creatinina plasmáticas escore de lesão histológica e avaliação da citometria de fluxo,sendo as diferenças consideradas significantes quando <0,05.A glicemia (mg.dL-1) em M2 foi maior nos grupos... / The hyperglycemia augments the renal ischemic-reperfusion injury (IRI) in rats anesthetized with isoflurane (Iso). This effect with propofol (Prop) is unknown. The purpose of this investigation was to examine the effect of isoflurane and propofol in renal ischemia/reperfusion injury (IRI) during transient hyperglycemia.Rats were randomly assigned in six groups of six animals, groups: PHS (Prop + Hyperglycemia - Sham); IHS (Iso + Hyperglycemia - Sham); PHI (Prop + Hyperglycemia + Ischemia); IHI (Iso + Hyperglycemia + Ischemia); PI (Prop + Ischemia) and II (Iso + Ischemia). Propofol in a dose of 1 mg.kg-1.min-1 (PHS, PHI and PI) or saline was infused (IHS, IHI and II). Mean arterial pressure (MAP) was monitored for anesthesia control. Hyperglycemia was induced with the injection of 2.5 g.kg-1 of glucose solution. All animals underwent to right nephrectomy. The two sham groups underwent to hyperglycemia with ischemia. The others groups were submitted to a left renal ischemia for 25 minutes. Serum creatinine and glucose values were determined in the beginning (M1) and at the end of experiment (M2) and 24 hours after the experiment (M3) rats were anesthetized with isoflurane and blood sample was collected and the left kidney removed for histological analysis, using a scale for tubular necrosis (0-5 = injury maximum). In addition to a histological study, cells from the left kidney were evaluated for apoptosis by flow cytometry (FCM) as a % of initial apoptosis (APTi) and viable cell (VC). Statistical analysis were applied to the values of MAP, serum creatinine and glucose, histological score injury and FCM and statistical differences were considered when p<0.05.Serum glucose at M2 was higher in PHS (351.8±141.0) and IHI (348.3±52.3) in relation to groups PI (147.0±62.4) and II (162.7±40.2). Groups IHS (302.5±80.0) and PHI (308.5±74.5) showedintermediary values. Serum creatinine... (Complete abstract click electronic access below)

In the 19th century, halothane hepatitis became a sensitive and well-known subject in human anesthesiology due to the production of a noxious metabolite further discovered, trifluoroacetic acid. Subsequently, isoflurane, enflurane, and desflurane were also investigated for potentially causing hepatitis through the same metabolite. Sevoflurane, however, does not generate trifluoroacetic acid and is quickly conjugated and excreted. For more than four decades these anesthetics have been experimentally developed for intravenous injection by having added either a lipid or fluorocarbon-based carrier to produce general anesthesia with less drug and faster onset of action. The use of intravenous emulsified halogenated anesthetics as an alternative to inhalation brought contradictory findings, therefore they are still not utilized in the clinical settings of veterinary and human anesthesia. The high solubility of these anesthetic emulsions increases their tissue uptake, volume of distribution, and potency. By this means, the amount of anesthetic necessary to establish general anesthesia could be significantly reduced but would still carry the risk of causing hepatic toxicity. On the other hand, because the emulsified anesthetics have a higher tissue uptake and are liposoluble, they remain for longer periods in the cellular membrane providing cellular pre- and postconditioning effects by minimizing cellular deleterious responses to a critical environment. Emulsified isoflurane and sevoflurane are the most investigated anesthetics for this purposein the heart, brain, kidneys, liver, and central nervous system of laboratory animals and human volunteers. The focus of this study is to evaluate the cellular effects of the loaded-lipid emulsified isoflurane and sevoflurane at different concentrations on cultured primary canine hepatocytes considering their viability and apoptosis response. Specifically, the overall objective is to establish a basis for in vitro metabolism of these emulsified anesthetics on canine hepatocytes under normal oxygen tension and on canine hepatocytes exposed to extreme hypoxia (1% O2). Thus, this study is sectioned into three major chapters followed by conclusions and future studies to determine the safety and indication of these anesthetic formulations in canine hepatocytes to be further explored in the clinical setting with live animals.

Despite being integral to the practice of surgery, the mechanisms by which general anesthetics mediate their effects remain unknown. For this reason, it is difficult to predict adverse side-effects and to determine how treatment should be modified for specific patient populations. Recent clinical studies have reported post-operative neuropsychological and behavioral abnormalities in children and protracted periods of post-operative cognitive decline in elderly patients. Definitively linking these post-operative consequences to the agents used to induce anesthesia has been difficult, due to a lack of proper clinical controls and an abundance of confounding health factors. Animal studies, have repeatedly shown that general anesthetics can be neurotoxic and lead to lasting impairments in learning and memory acquisition in both the very young and old. However, the scope and causes of these post-exposure impairments and the reasons why age seems to measurably affect outcomes remain unclear. Here we employ multi-neuronal fluorescence imaging in the nematode Caenorhabditis elegans to measure changes in neuronal activity and connectivity across the animal’s nervous system, following exposure to the volatile anesthetic isoflurane during neurodevelopment and senescence. Employing transgenic expression of the fluorescent calcium indicator GCaMP6s, we measure neuronal activity of specific command interneurons as well as across the majority of the nervous system with single cell resolution. Isoflurane exposure during developing, results changes in the transition rate between neuronal activity states and an overall increase in excitatory connectivity. Importantly these effects are dependent on cellular stress pathways involved mTOR and daf-16 but not on apoptotic cell death (medatied by ced-3). Measuring neuronal activity across the animals lifespan, we identify substantial age-related alterations to neural activity, connectivity and functional organization of the system. These include a progressive loss of system-wide organization and a corresponding shift in individual neuron activity toward higher frequencies. We also observe a specific loss of anti-correlative (i.e. inhibitory) signaling between neurons, resulting in an overall shift in the excitatory/inhibitory balance of the system. In support of this, we find that application of the GABAA agonist muscimol diminishes certain aspects of nervous system decline in aged animals. We further identify genes that either hasten or delay the progression toward senescent neural activity patterns, including the presynaptic voltage-gated Ca2+ channel UNC-2/CaV2, and also CED-4, a key mediator of the conserved cell-death pathway. Finally, imaging post-exposure consequences of isoflurane during senescence reveals long term effects on neuronal signaling that involved a decrease in excitatory connectivity, the opposite of what is observed during development. We conclude that anesthetic exposure during development cause permanent alteration in neuronal activity and signaling which involves cellular stress pathways but that these effects are distinct from long-term effect of anesthetic exposure we observe in age animals. Our studies also begin to define the changes in neuronal dynamics with age and demonstrate the importance of excitatory/inhibitory balance in this processes. Through comprehensive multi-neuronal imaging in C. elegans, we are able to measure the progressive breakdown of neuronal activity and system dynamics with age and isoflurane exposure and begin to identify the cellular processes and changes in synaptic signaling that contribute to these declines. Moreover, we leverage this platform to gain insight into the age-dependency of isoflurane-induced insult to neural systems.

No description available.

Le neuropaludisme (NP) est la forme la plus mortelle du paludisme. C'est une complication neurologique observée uniquement dans les cas d'infection par Plasmodium falciparum, principalement chez les enfants de moins de 5 ans vivant en Afrique Sub-saharienne, et les adultes non-immuns, notamment les femmes enceintes et les touristes visitant les zones d'endémie. Les signes cliniques sont à présent bien décrits (prostration, convulsions répétées, difficultés respiratoires, coma,...), mais les mécanismes physiopathologiques conduisant au NP sont encore mal définis. Leur élucidation est rendue difficile par la localisation cérébrale de la pathologie du vivant des patients et la faible disponibilité des données nécropsiques. Bien que l'accès aux tissus humains soit limité en nombre, les résultats d'autopsie ont permis d'établir que le NP résulte d'une séquestration des globules parasités au niveau de l'endothélium intra-vasculaire, associée à une forte réaction immunitaire. La stratégie de prise en charge du NP combine un traitement étiologique à base de dérivés d'artémisinine, ou de quinine et un traitement adjuvant symptomatique destiné à pallier à la défaillance multiorganique qui est à l'origine de l'issue fatale souvent observée. Le modèle de NP expérimental actuellement le plus utilisé est le modèle souris infecté par P. berghei ANKA. La pertinence de ce modèle est toutefois remise en cause en raison notamment des différences histo-pathologiques observées par rapport à la forme humaine. En effet, les souris manifestant les symptômes du NP ne présentent que très rarement le phénomène de séquestration, caractéristique majeure du NP chez l'Homme. Par ailleurs, comparativement à la réponse immunitaire de la souris, le modèle rat s'est également révélé plus proche de la réaction de l'Homme, dans le cas d'une autre parasitose, la schistosomose. L'objectif de la première partie du projet thèse a donc été la mise en place et l'évaluation d'un modèle alternatif de NP chez le rat. Ainsi un modèle de NP chez le rat Sprague Dawley infecté par la souche murine P. berghei K173 a été caractérisé sur les plans clinique, biologique (paramètres hématologiques et biochimiques),histopathologique et du profil cytokinique (cytokines cérébrales et sériques). La forte similarité des symptômes et des lésions associées au NP du rat Sprague Dawley infecté par P. berghei K173 par rapport au NP humain permet de valider la pertinence de ce modèle pour l'étude de la physiopathologie du NP. L'objectif de la deuxième partie de mon projet de thèse a été d'évaluer les effets pharmacologiques d'un candidat-médicament, l'isoflurane, pour le traitement adjuvant du NP. Ce composé présente l'avantage d'être déjà utilisé chez l'Homme à d'autres fins thérapeutiques et dispose donc d'une autorisation de mise sur le marché. Les résultats obtenus montrent une efficacité nette de l'isoflurane avec une rémission totale des signes de paralysie pour 47.8% des rats traités ainsi qu'un gain de survie des rats NP traités de 2 à 10 jours par rapport aux rats NP non traités. Ce gain de survie des animaux traités pourrait permettre un allongement de la fenêtre du temps de traitement étiologique, améliorant ainsi sensiblement le pronostic du NP. L'isoflurane, dont le mécanisme d'action semble être la réversion de la séquestration des globules parasités, limite les complications neurologiques souvent responsables de séquelles liées au NP. Des études ultérieures permettront d'optimiser ce nouveau protocole de traitement adjuvant du NP. / Cerebral malaria (CM) is the most deadly form of malaria. It is a neurological complication observed only in cases of infection with Plasmodium falciparum that affects mainly children under five years living in Sub-Saharan Africa and non-immune adults including pregnant women and tourists visiting endemic areas. Although clinical signs are well described (prostration, respiratory distress convulsions, coma), the pathophysiological mechanisms leading to CM are still unclear. Their elucidation in vivo is made difficult by the cerebral location and the low availability of autopsy data. Instead of limited access to human tissues, autopsy results have shown that CM results from a strong immune response linked to sequestration of infected red blood cells in the intravascular endothelium. Cerebral malaria management combines an etiological treatment with artemisinin derivatives or quinine and adjunct treatment of the multi-visceral failures, responsible of fatal outcome. P. berghei ANKA-infected mouse is widely used as experimental murine model of CM. However the relevance of this model is still questioned because of the histopathologic differences from the human form. Indeed, CM mice rarely exhibit the red blood cell sequestration that is a major feature of human CM. Furthermore, compared to mouse, the rat displays a closer immune response to human in Schistosoma infection. This PhD research project first aimed to implement and assess an alternative rat model of CM. The clinical, biological, histo-pathological features as well as the cytokine profiling of an experimental model of CM were characterized in Sprague Dawley rats infected with P. berghei strain K173. The strong similarity of the symptoms and lesions observed in this model with those reported in human CM confirms its high relevance. The second objective of this thesis project was to assess the pharmacological effects of a drug-candidate in adjunct treatment of CM. Results demonstrated a strong efficacy of the molecule tested with 47.8% of the treated CM rats showing total remission. Moreover we observed a 2- to 10-day survival gain in the treated CM rats group compared to the non-treated CM rat group. Preliminary data suggest that this drug-candidate may reverse the endothelial sequestration of parasitized red blood cells and so limit the neurological sequels related to CM. It is anticipated that the gain in survival associated with this drug-candidate use will extend the window of the etiological treatment time, thus significantly improving the global prognosis of CM. Further studies are needed to optimize this adjunct CM treatment protocol.

La photocatalyse est une technologie d’oxydation avancée qui peut être utilisée pour améliorer la qualité de l'air dans les environnements intérieurs et pourrait être mise en œuvre dans les milieux médicaux. Dans les hôpitaux, les salles d'opération sont très exigeantes en matière de qualité de l'air intérieur et nécessitent des systèmes qui minimisent les concentrations des polluants générés par les différentes activités. Dans ce travail, le devenir de deux polluants spécifiques des blocs opératoires, l’acrylonitrile (produit chimique trouvé dans la fumée chirurgicale) et l'isoflurane (gaz anesthésique) lorsqu'ils passent dans un dispositif de traitement d’air photocatalytique est étudié. Tout d'abord, une évaluation paramétrique de la dégradation de l'isoflurane et de l'acrylonitrile en étudiant l'influence de la vitesse de l'air, de l'intensité lumineuse, de la géométrie du média photocatalytique, de la concentration initiale en polluants, de la présence de co-polluants chimiques, de la présence de particules et l’humidité relative sur leur efficacité de dégradation est réalisée. En second lieu, l’innocuité de l’utilisation de ce procédé pour la dégradation de l’isoflurane et de l’acrylonitrile par l’identification des éventuels intermédiaires formés au cours de leur dégradation est étudiée. Les expériences sont menées dans un réacteur dynamique en boucle fermée conçu pour étudier les polluants à faibles concentrations. Enfin, pour mieux comprendre comment le changement de géométrie du média photocatalytique influence l'efficacité de la dégradation, des simulations avec ANSYS14.5 sont effectuées et discutées au regard des résultats expérimentaux. / Photocatalytic oxidation (PCO) is an advanced air cleaning technology that is used asa means to improve air quality in indoor environments and could potentially be used inthe operating rooms (OR). In hospitals, operating rooms (ORs) are very demanding interms of the indoor air quality (IAQ) and require systems that minimize the concentrations of pollutants. In this work, the fate of two OR pollutants acrylonitrile (chemical found insurgical smoke) and isoflurane (anesthetic gas) when they go through a PCO device was investigated. Firstly, a parametric evaluation on the degradation of isoflurane and acrylonitrile by studying the influence of air velocity, light intensity, the change in media geometry, initial pollutant concentration, presence of chemical co-pollutants, presence of particles (bioaerosols) and relative humidity on their degradation efficiencies is performed. Secondly the safety of the use of PCO for the degradation of isoflurane and acrylonitrile through the identification of possible intermediates formed during their degradation is evaluated. The experiments were conducted in a closed loop reactor which has been designed to study low concentration air pollutants and has also been recently modeled. Finally, to better understand how the change in media geometry influenced the degradation efficiency, simulations with ANSYS 14.5 were performed and discussed.