O uso recreacional e os efeitos deletérios de drogas lícitas e/ou ilícitas é considerado um problema de saúde pública. Dentre estas drogas destaca-se a cetamina, um anestésico empregado na veterinária e o etanol, a droga lícita mais utilizada. Além dos efeitos centrais, estudos revelam que a cetamina e o etanol possuem propriedades imunomodulatórias. No entanto, poucos estudos são realizados com a associação destas drogas; assim, o objetivo deste estudo foi o de avaliar os efeitos tóxicos, imunotóxicos, o potencial oxidativo e os possíveis efeitos neurotóxicos resultantes do consumo associado ou não das mesmas. Para isso, ratos Wistar foram tratados uma vez ao dia, por até 28 dias, com injeções intraperitoneais (15 ou 30mg/kg/PV) de cetamina (K) ou com etanol a 10% (E) via oral (gavagem ou adicionado a água de bebida), ou ainda em associação (KE). O grupo controle recebeu apenas os veículos dos tratamentos. Ao final do experimento, os animais foram submetidos à eutanásia para realização de avaliações toxicológicas, imunológicas, oxidativas e antioxidativas, e de neurotransmissores centrais. Os resultados revelaram redução no ganho de peso dos animais tratados com KE e aumento de ácido ascórbico urinário. A redução de pH e glicose urinária foi observada nos grupos E e KE. Na bioquímica, todos os grupos apresentaram aumento de HDL, porém a associação das drogas levou a um aumento do colesterol, enquanto no grupo K, observou-se diminuição dos triglicérides e da fosfatase alcalina. Ainda, somente o grupo KE apresentou alterações na função renal. Todos os grupos experimentais exibiram alterações histopatológicas hepáticas e/ou vesicais. Os grupos E e KE apresentaram alterações no número de células mieloides e linfoides concomitantes ao aumento na celularidade de medula óssea. Apenas animais do grupo KE apresentaram alteração na resposta do tipo Th2. Foi observado o aumento da peroxidação lipídica nos animais tratados com K, bem como aumento na atividade de GPx e CAT e do conteúdo de GSSG dos animais tratados com E e/ou KE nos órgãos analisados. Ao nível central, observou-se elevação dos níveis de DA e NOR no hipocampo dos animais do grupo E, e 5HT nos animais do grupo K; além de aumento de DA e 5HT no córtex pré-frontal dos animais dos grupos E e K, respectivamente. Assim, concluímos que a associação KE promove redução do ganho de peso não relacionado ao consumo de ração. O etanol, em associação ou não, promove alterações nos parâmetros urinários; a cetamina promove diminuição nos níveis de FA e as drogas quando em associação alteram o perfil lipídico e renal na dependência da dose e do tempo de administração. Efeitos pró-oxidantes entraram em equilíbrio devido à ação de antioxidantes. O etanol, em associação ou não, promove alterações em células do sistema imune, no entanto, sem promover imunomodulação sobre suas respostas. O etanol e/ou a cetamina também promovem alterações histopatológicas hepáticas, enquanto que a associação ainda promove lesões vesicais. Além disso, ambas as drogas promovem alterações no perfil neuroquímico central; porém, quando associadas não promoveram efeitos sinérgicos sobre os parâmetros avaliados. / The recreational use and the deleterious effects of licit and/or illicit drugs are considered a public health issue. Among these drugs are ketamine, used in veterinary anaesthesia, and ethanol the most commonly licit drug. Besides their central effects, studies have shown that ketamine and ethanol have immunomodulatory properties. However, few studies are conducted with the association of both drugs; thus, we aimed to evaluate the toxic and immunotoxic effects, as well the oxidative potential and the possible neurotoxic effects resulted from the consumption of these drugs associated or not. For this, Wistar rats were treated once daily for up to 28 days with intraperitoneal injections (15 or 30mg/kg/BW) of ketamine (K) or orally with 10% ethanol (E) (gavage or drinking water) or the association of both treatments (KE). Control group received only vehicles. At the end of the experimental period, the animals were euthanized for toxicological, immunotoxicological, oxidative stress and antioxidant status evaluation, and central levels of neurotransmitters. KE animals showed reduced body weight gain and increased levels of urinary ascorbic acid. Reduction of urinary pH and glucose was observed in E and KE groups. Biochemistry analysis showed an increase in HDL levels in all experimental groups; although, KE showed an increase in cholesterol levels, while K group exhibited reduction in triglycerides and alkaline phosphatase (ALP) levels. Only KE group showed renal function alterations. All experimental groups showed hepatic and/or bladder histopathology alterations. E and KE groups exhibited alterations in myeloid and lymphoid cells number with concomitant increased in bone marrow cellularity. Only animals of KE group presented changes in Th2 response. Increased in lipid peroxidation was observed in K-treated animals, as well as GPx and CAT activities and GSSG content of animals treated with E and/or KE. We observed elevation in DA and NOR in hippocampus of E group and 5HT in K group, in addition to an increase in DA and 5HT of the prefrontal cortex of E and K groups, respectively. Thus, we conclude that KE association promotes reduction in body weight gain not related to food consumption. Ethanol, in combination or not, promotes urinary alterations; ketamine reduces ALP levels and the drugs, when in combination, alter lipid and renal profile depending on dose and time of administration. Pro-oxidant effects were balanced due to the action of antioxidants. Ethanol, associated or not, promotes alterations on immune cells without immunomodulatoty responses. Ethanol and/or ketamine also promotes liver histopathological alterations, while this association promotes bladder lesions. In addition, both drugs promote changes in central neurochemical levels; however, when associated do not promoted synergistic effects in evaluated parameters.

Submitted by Eunice Novais (enovais@uepg.br) on 2018-08-15T17:01:17Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Lillian Caroline Fernandes.pdf: 1580382 bytes, checksum: e37251c84c29f43f323382ed3a322f10 (MD5) / Made available in DSpace on 2018-08-15T17:01:17Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Lillian Caroline Fernandes.pdf: 1580382 bytes, checksum: e37251c84c29f43f323382ed3a322f10 (MD5) Previous issue date: 2018-02-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / O aumento progressivo da população e da produção de alimentos torna o uso de agrotóxicos essencial. O Brasil tem notoriedade à nível mundial na quantidade desses produtos comercializados, sendo destaque desde 2008. As classes mais utilizadas são os herbicidas, fungicidas e inseticidas. Sabe-se que esses produtos apresentam risco a saúde humana, podendo afetar múltiplos sistemas. Além disso, alguns estudos estão demonstrando efeitos neurotóxicos e comportamentais causados por esses agentes, no entanto, o mecanismo desse efeito permanece incerto. Os pesticidas têm diferentes mecanismos de ação e ainda, podem apresentar efeitos sinérgicos entre si. Com isso, o presente estudo busca avaliar se a exposição ao Paraquat, que é um herbicida, amplamente utilizado devido ao seu baixo curso e amplo espectro de forma isolada e as associações com Mancozeb, que é um fungicida e com o Clorpirifós, que é um inseticida são capazes de produzir efeitos comportamentais. Para isso, foram utilizados 48 ratos machos da linhagem Wistar divididos em 4 grupos de acordo com o agente de exposição: Controle/Água (N=12), Paraquat 1mg/kg (N=12), Paraquat 1mg/kg e Mancozeb 3 mg/kg (N=12), Paraquat 1mg/kg e Clorpirifós 0,3 mg/kg (N=12). A exposição ocorreu diariamente durante 28 dias por via oral (gavagem). Após o período de exposição, foram realizados os testes de preferência à sacarose, reconhecimento social, campo aberto, reconhecimento de objetos, labirinto em cruz elevado e natação forçada. Como resultado têm-se que os animais submetidos ao tratamento apresentaram déficit na memória social e declarativa, evidenciado pelo teste de reconhecimento social e de objetos. Além disso, apresentaram também sinais do tipo ansiogênicos e depressivos demonstrado pelo teste de labirinto em cruz elevado e natação forçada. Além dos sinais não motores os animais também apresentaram comprometimento motor, evidenciado pelo teste de campo aberto. Como conclusão, demonstramos que a exposição ao Paraquat e associações com Mancozeb e Clorpirifós causou alterações comportamentais nos animais submetidos a exposição com Paraquat e associação com Mancozeb e Clorpirifós. / The progressive increase in population and food production makes the use of agrochemicals essential. Brazil is known worldwide in the quantity of these products marketed, being highlighted since 2008. The classes most used are herbicides, fungicides and insecticides. It is known that these products pose a risk to human health and can affect multiple systems. In addition, some studies are demonstrating neurotoxic and behavioral effects caused by these agents, however, the mechanism of this effect remains uncertain. Thus, the present study aims to evaluate whether exposure to Paraquat, which is a herbicide, widely used because of its low cost and broad spectrum in isolation and as associations with Mancozeb, which is a fungicide and with Chlorpyrifos, which is an insecticide are capable of producing effects. For this, 48 male Wistar rats divided into 4 groups according to the exposure agent: Control/Water (N= 12), Paraquat 1mg/kg (N=12), Paraquat 1mg/kg and Mancozeb 3 mg/kg (N = 12), Paraquat 1 mg/kg and Chlorpyrifos 0.3 mg/kg (N = 12). The exposure occurred daily for 28 days orally (gavage). After the exposure period, sucrose preference tests, social recognition, open field, object recognition, elevated plus maze and forced swimming were performed. As a result, the animals submitted to the treatment had deficits in the social and declarative memory, evidenced by the test of social recognition and objects. In addition, they also presented anxiogenic and depressive signs, demonstrated by the elevated plus maze test and forced swimming. In addition to non-motor signals, the animals also presented motor impairment, evidenced by the open field test. As a conclusion, we demonstrated that exposure to Paraquat and associations with Mancozeb and Chlorpyrifos caused behavioral changes in animals submitted to Paraquat exposure and associated with Mancozeb and Chlorpyrifos.

L’irradiation cérébrale thérapeutique comporte un risque de neurotoxicité tardive irréversible en partie lié à l’effet de l’irradiation sur le compartiment vasculaire cérébrale. Les péricytes et les communications entre les péricytes et les cellules endothéliales jouent un rôle majeur dans la stabilisation des vaisseaux, dans la formation et la régulation de la barrière hématoencéphalique et dans le contrôle du flux sanguin cérébral. Nous montrons, dans un modèle murin d’irradiation cérébrale, que les péricytes sont une cible précoce de l’irradiation cérébrale. Après irradiation, la morphologie des péricytes est modifiée et des marqueurs d’activations du péricytes sont surexprimés. En conséquence, la communication entre péricyte et cellule endothéliale est rompue, ce qui se traduit par une diminution de la capacité du péricyte à induire une constriction vasculaire après stimulation électrique. De façon concomitante, la perméabilité de la barrière hémato-encéphalique est anormalement augmentée après irradiation. Un traitement par thalidomide, administré dans la semaine précédant et suivant l’irradiation, prévient les conséquences de l’irradiation sur les péricytes. Les communications entre péricytes et cellules endothéliales sont maintenues ainsi que les fonctions contractiles des péricytes. L’imperméabilité de la barrière hématoencéphalique est également préservée. La voie de signalisation PDGF-β/PDGFR-β essentielle au recrutement des péricytes par les cellules endothéliales, est, au moins partiellement, impliquée dans l’effet protecteur de la thalidomide. Des études supplémentaires sont nécessaires pour définir les mécanismes sous tendant l’effet de l’irradiation sur les péricytes ainsi que l’effet protecteur de la thalidomide. Nous avons en parallèle mis au point un modèle murin de lymphome cérébral luciférase positif pour vérifier, dans un premier temps, l’innocuité de l’association de la radiothérapie et de la thalidomide et de ses dérivés de la classe des immunomodulateurs (iMids), le lénalidomide et le pomalidomide. Ces trois molécules ne diminuent pas l’effet antitumoral de la radiothérapie, mais l’association de radiothérapie et de pomalidomide est synergique sur la décroissance tumorale mesurée par l’évolution des courbes de bioluminescence. Le concept de normalisation de la vascularisation tumorale fait référence aux molécules capables, non pas de faire régresser les vaisseaux tumoraux anormaux, mais de les « normaliser » pour améliorer, d’une part, la disponibilité des chimiothérapies au sein de la tumeur, et d’autre part, l’oxygénation tumorale pour accroitre l’efficacité de la radiothérapie. Nos résultats sont en faveur d’un tel effet exercé par le pomalidomide dans notre modèle murin de lymphome cérébral, caractérisé par une infiltration tumorale périvasculaire, une fuite capillaire mais sans néo angiogenèse. Nos travaux fournissent un rationnel biologique à de futurs essais cliniques avec les iMids dans le traitement des lymphomes cérébraux primitifs voire des tumeurs malignes cérébrales. / Therapeutic brain irradiation carries a risk of irreversible delayed neurotoxicity partly due to the effect of irradiation on the cerebral vascular compartment. Pericytes and communication between pericytes and endothelial cells play a major role in vessel stabilization in the formation and regulation of the blood-brain barrier and in the control of cerebral blood flow. We show in a murine model of brain irradiation, that pericytes are a target of early brain irradiation. After irradiation, the morphology of pericytes is altered and markers of activation of pericytes are overexpressed. Consequently, communication between the endothelial cell and pericyte is disrupted , which results in a decreased capacity of pericytes for inducing a vascular constriction after electrical stimulation. Concomitantly, the permeability of the blood - brain barrier is abnormally increased after irradiation. Treatment with thalidomide administered in the week before and after irradiation, prevents the effects of irradiation on pericytes . Communication between pericytes and endothelial cells are maintained as well as the contractile properties of pericytes. The impermeability of the blood brain barrier is also preserved. The PDGF-β/PDGFR-β signaling pathway, which is essential for the recruitment of pericytes by endothelial cells, is at least partially involved in the protective effect of thalidomide. Further studies are needed to define the mechanisms underlying the effect of irradiation on the pericytes and the protective effect of thalidomide. We have, in parallel, developed a model of murine luciferase positive CNS lymphoma to verify first, the safety of the combination of radiotherapy and thalidomide and its derivatives of the class of immunomodulators ( IMiDs ), lenalidomide and pomalidomide. These three molecules do not decrease the antitumor effect of radiotherapy, but the antitumoral effect of the association of radiotherapy and pomalidomide is synergistic. The concept of the normalization of the tumor vascularization refers to molecules capable not to induce regression of the abnormal tumor vessels but to "normalize" the tumoral vasculature in order to improve, on one hand , the availability of chemotherapy in the tumor , and on the other hand, the tumor oxygenation to increase the effectiveness of radiotherapy. Our results are in favor of such an effect exerted by pomalidomide in our murine model of cerebral lymphoma, characterized by perivascular tumor infiltration and capillary leak .Our work provide a biological rational for future clinical trials with IMiDs in the treatment of brain lymphomas or malignant brain tumors.

Orientador: Eliana Marisa Ganem / Resumo: Justificativa e objetivo: Cada vez mais o anestesiologista se depara com a necessidade de decidir por realizar ou não bloqueio de neuroeixo através da pele tatuada, já que o número de pessoas com tatuagem tem aumentado. Neste estudo foi avaliado se a punção subaracnoidea sobre área tatuada provoca alterações inflamatórias agudas nas meninges e medula espinal e se pode evoluir para aracnoidite adesiva. Material e Método: 42 coelhos machos foram divididos, aleatoriamente, em 3 grupos de 14 animais: G1, punção subaracnoidea através de pele não tatuada e injeção de solução salina, cativeiro 30 dias; G2, punção subaracnoidea através de pele tatuada e injeção de solução salina, cativeiro 30 dias; G3, punção subaracnoidea através de pele tatuada e injeção de solução salina, cativeiro 360 dias. Os animais foram anestesiados com cloridrato de xilazina e cloridrato de cetamina e realizou se punção subaracnoidea, guiada por ultrassom, no espaço intervertebral entre S1 – S2, com injeção de solução salina 0,2mL. Após período de cativeiro os animais foram sacrificados, sob anestesia, por decapitação e a porção lombossacra da medula espinal foi removida para análise histológica. Resultados: Nenhuma alteração histológica foi encontrada nos animais do grupo 1. Onze animais do grupo 2 apresentaram focos de infiltrado inflamatório linfocitário perivascular na pia-máter e/ou aracnoide. No grupo 3, oito coelhos apesentaram infiltrado inflamatório linfocitário ou linfoplasmocitário perivascular e ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Background and Objectives: As the number of people with tattoos has been increasing, anesthesiologists are more and more faced with the decision to perform a neuraxial blockage through tattooed skin. In this study, we evaluated the possibility of puncture through tattooed skin determines acute inflammatory changes in the meninges and spinal cord and later evolve into adhesive arachnoiditis. Method: Forty-two male rabbits were randomized into 3 equal groups of 14: G1, spinal puncture through non-tattooed skin and saline solution injection; G2, spinal puncture through tattooed skin and saline solution injection, captive for 30 days; G3, spinal puncture through tattooed skin and saline solution injection, captive for 360 days. The animals were anesthetized and ultrasound-guided spinal puncture was performed in the intervertebral spaces between S1–S2. During the period of captivity, the animals were clinically assessed for sensitivity and motor function. After that, they were sacrificed and the lumbosacral portion of the spinal cord was excised for histological analysis. Results: No histological changes were found on group 1. Eleven animals from group 2 presented with foci of perivascular lymphocytic inflammatory infiltrate in the pia mater and/or arachnoid. In Group 3, 8 rabbits presented with inflammatory changes in the meninges, which were associated with thickening and/or adhesion of the pia mater and arachnoid in some cases and 5 rabbits presented only thickening of pia-mate... (Complete abstract click electronic access below) / Doutor

O chá ayahuasca é uma bebida psicotrópica que tem provocado polêmica devido ao uso indiscriminado por alguns grupos de pessoas e pela facilidade de compra pela internet. A bebida é feita por meio da decocção conjunta das plantas Banisteriopsis Caapi e Psychotria Viridis. Contém alcaloides beta-carbolínicos (?-carbolínicos) como harmina (HRM), harmalina (HRL) e harmalol, que possuem efeitos inibidores da monoaminooxidase A (MAO-A), sendo considerados protetores contra o dano oxidativo neuronal, além de ter ações anticonvulsivantes e efeitos ansiolíticos. Por outro lado, esses alcaloides, conjuntamente com a N,N-dimetiltriptamina, principal componente alucinógeno da P. Viridis, também têm sido descritos como neurotoxinas endógenas que podem participar no início de doenças neurodegenerativas. No presente estudo, a neurotoxicidade do chá ayahuasca foi estudada por meio da determinação da ocorrência de apoptose neuronal pelo método de fluorescência da Caspase-3 e pelo ensaio do TUNEL (Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay). Foram administrados, diariamente, durante vinte e um dias, por meio de gavagem gástrica, 2 ml de água a um grupo de ratos Wistar machos, controle (n=12) e 2 ml do chá ayahuasca 50% a outro grupo similar (n=12). Foram realizadas análises de glutationa (GSH), malonaldeído (MDA) e vitamina E séricas e hepáticas para avaliar a peroxidação lipídica (LPO), assim como análises urinárias de creatinina e ureia para avaliar o funcionamento renal dos animais. Os resultados nas análises do TUNEL mostraram significância estatística no grupo ayahuasca em relação ao grupo controle. A análise de Caspase-3 não mostrou diferenças entre os dois grupos. Os valores de MDA e GSH sérica, assim como da vitamina E hepática, apresentaram redução estatisticamente significativa no grupo tratado com o chá ayahuasca. Os resultados desta investigação apontam para a presença de um processo de estresse oxidativo nos ratos tratados com este chá, com achados estatisticamente significativos de apoptose neuronal com o ensaio do TUNEL. É recomendável a realização de outros estudos para elucidar os mecanismos neurotóxicos do chá ayahuasca. / Ayahuasca tea is a psychotropic beverage that has caused controversy due to the fact of being used indiscriminately by some group of people and the ease of purchase in the worldweb. The tea is derived by boiling the bark of the liana Banisteriopsis Caapi (B. Caapi) together with the leaves of Psychotria Viridis (P.Viridis). B. Caapi contains alkaloids as harmine, harmaline and harmalol, highly active reversible inhibitors of monoamine oxidase A and MAO-B. These compounds have been described as protecting neuronal mitochondria against oxidative damage, besides having anticonvulsivant and anxiolytic actions. On the other hand, these alkaloids, together with dimethyltryptamine (DMT), the main hallucinogenic component of P. Viridis, also had been described as endogenous neurotoxins that could participate in neurodegenerative diseases. In this work, the neurotoxicity of ayahuasca was studied by the method of fluorescence of Caspase-3 and the TUNEL assay. By gastric gavage, was administered in a daily regime during twenty-one days, 2 ml of water to a group of rats (control n=12) and 2 ml of 50% ayahuasca tea to another similar group (n=12). Analysis of reduced glutathione (GSH), malonaldehyde (MDA) and vitamin E was made, to assess lipid peroxidation and also analysis of urinary urea and creatinine, to assess kidney function of animals. The results of the TUNEL assay, showed statistical significant values in the ayahuasca group. No differences were found in Caspase-3 analysis. The values of serum MDA and GSH as well as hepatic vitamin E, showed a statistically significant reduction in the group treated with ayahuasca. The results of this investigation indicate the presence of oxidative stress in rats treated with ayahuasca tea, with statistical significant values of neuronal apoptosis measured by TUNEL assay. It is advisable to conduct further studies to elucidate the neurotoxic effects of ayahuasca tea.

O manganês (Mn) é um elemento químico abundante na natureza, principalmente em minérios e presente também em alimentos e na água. É o cofator de enzimas importantes, como a superóxido dismutase mitocondrial. Entretanto, mineradores e outras pessoas expostas a produtos manufaturados de Mn podem apresentar uma concentração excessiva desse metal no cérebro, adquirindo uma desordem neurológica similar ao mal de Parkinson conhecida por manganismo. Basicamente a neurotoxicidade do Mn pode estar associada com os vários estados de oxidação que ele pode alcançar, gerando espécies reativas de oxigênio durante a interconversão dessas espécies. Dessa forma, neste trabalho sintetizamos e avaliamos as propriedades pró-oxidantes e neurotóxicas de complexos de Mn(III) com desferrioxamina, [Mn(dfb)]; acetohidroxamato, [Mn(aha)3]; citrato, [Mn(cit)]; cloro-salen, EUK 8; e aceto-salen, EUK 108. Tais compostos são propostos como miméticos da SOD e/ou catalase, entretanto podem apresentar atividade pró-oxidante. Estes complexos foram caracterizados espectrofotometricamente (UV/Vis e IV) e por voltametria cíclica. Foram determinadas as absortividades molares dos complexos [Mn(aha)3], EUK 8 e EUK 108. Os EUK\'s apresentaram dois processos redutivos, sendo apenas um reversível, enquanto o [Mn(cit)] apresentou apenas um processo redutivo reversível e os hidroxamatos [Mn(dfb)] e [Mn(aha)3] não apresentaram processos redox na faixa de potenciais utilizada. Em teste de lipofilicidade todos os complexos apresentaram maior afinidade pela fase aquosa, sendo muito pouco particionados para a fase orgânica. Através do ensaio de supressão de fluorescência de calceína foi possível estabelecer que os EUK\'s são relativamente mais estáveis do que os outros complexos, sendo o [Mn(aha)3] o menos estável dos compostos estudados. Nas análises de atividade pró-oxidante, o [Mn(dfb)] oxidou fortemente a sonda mesmo na ausência de outros cofatores, mas este processo é dependente da concentração de O2 no meio. Os EUK\'s atuaram como pró-oxidantes em função da concentração de peróxido no meio. A atividade pró-oxidante foi suprimida por ascorbato, glutationa e Trolox®, que agiram como antioxidantes, sugerindo implicações para a terapia do manganismo. O teste de toxicidade aguda em paulistinhas (Danio rerio) adultos resultou na mortalidade de alguns animais quando expostos a [Mn(dfb)] e [Mn(aha)3]. Comparando o telencéfalo de peixes expostos ao [Mn(dfb)] com um controle em microscópio, não se visualizou nenhuma alteração morfológica na região do núcleo dorsal, indicando que o complexo não causou nenhum dano visível nessa região. / Manganese (Mn) is an abundant element which is present also in food and water. It is the cofactor of important enzymes such as mitochondrial superoxide dismutase. However, miners and other occupationally exposed individuals may present an excessive load of Mn in brain and develop manganism, a neurological disorder akin to Parkinson Disease. Basically, Mn neurotoxicity may stem from its wide redox cycle, generating reactive oxygen species in the process of converting from one oxidation state to another. Thus, in this work we synthesized and evaluated the pro-oxidant and neurotoxic characteristics of Mn(III) complexes with desferrioxamine, [Mn(dfb)]; acetohydroxamate, [Mn(aha)3]; citrate, [Mn(cit)]; chlorosalen, EUK 8; and aceto-salen, EUK 108. Such compounds are proposed as mimetics of superoxide dismutase and/or catalase, however they may also be prooxidant. These complexes were characterized spectrophotometrically (UV/Vis and IR) and by cyclic voltammetry. Molar absorptivities were determined for [Mn(aha)3], EUK 8 and EUK 108. EUK\'s displayed two reductive processes, only one of which was reversible, while [Mn(cit)] displayed only one (reversible) reductive process and hydroxamates [Mn(dfb)] and [Mn(aha)3] did not display redox processes in the working range of potentials. Lipophilicity tests showed that all complexes have very low partition to the organic phase. Calcein fluorescence quenching studies showed that both EUK complexes are relatively more stable than the others, while [Mn(aha)3] is the least stable. In the pro-oxidant activity studies, [Mn(dfb)] strongly oxidized the fluorescent probe even in the absence of ancillary substances such as peroxide. However, this effect was dependant on O2 saturation in the solution. Both EUK acted as pro-oxidants with a linear dependence on peroxide concentration. Pro-oxidant activity was eliminated by the treatment with antioxidants such as ascorbate, glutathione and Trolox®, which is of interest for the therapy of manganism. In the acute toxicity tests induced some mortality in adult Danio rerio exposed to [Mn(dfb)] or [Mn(aha)3]. Comparison of the telencephalus of [Mn(dfb)]-exposed individuals with controls failed to indicate morphological alterations in the dorsal nucleus area, indicating that the complex did not affect visibly this brain region.

Ao se estudar as causas da perda auditiva relacionada ao trabalho, geralmente a perda auditiva induzida por ruído é a mais referida, embora a literatura especializada aponta outros agentes presentes no ambiente de trabalho que podem ser nocivos à saúde do trabalhador. Os solventes são considerados alguns desses agentes e seus efeitos sobre o sistema auditivo vêm sendo investigado por alguns pesquisadores. O uso industrial destes solventes é vasto e, normalmente as condições de trabalho presentes num grande número de indústria brasileiras expõem o trabalhador a elevadas concentrações de solventes. A convivência com as substâncias químicas nos dias atuais é, portanto, obrigatória e permanente sendo particularmente importante para os trabalhadores envolvidos em processos produtivos que direta ou indiretamente utilizem estas substâncias em razão dos danos à saúde e ao ambiente que podem resultar de sua utilização. O risco e o perigo que estão relacionados com as substâncias químicas devem ser trabalhados nas suas várias dimensões entre as quais destacamos: o potencial de dano do produto, as condições ambientais e do trabalho em que as atividades se desenvolvem e o histórico conhecido daquela realidade e de outras semelhantes a partir dos dados epidemiológicos produzidos e do conhecimento científico existente. Este estudo avaliou o perfil audiológico e caracterizou o ambiente de trabalho de frentistas de postos de combustíveis. Os procedimentos desta pesquisa foram realizados em uma clínica particular de fonoaudiologia na cidade de Bariri, e a análise laboratorial foi realizada no laboratório São José, também na cidade de Bariri. Foram utilizados audiometria convencional e de altas frequências, logoaudiometria, imitanciometria, pesquisa das emissões otoacústicas, do Potencial Evocado Auditivo de Tronco Encefálico, exames clínicos laboratoriais, assim como avaliação do ruído ambiental. Nos resultados foram encontrados limiares dentro da normalidade em todos os casos, porém, todos eles apresentaram o traçado característico da perda auditiva ocupacional em evolução, ou seja com entalhes nas frequências de 3 a 6 KHz. Houve ainda alteração nos resultados do PEATE, com aumento de latência em 20 das 32 orelhas testadas. A pressão sonora variaram entre os postos, sendo que o Posto 1 não ultrapassou 80dB, enquanto o Posto 2 apresentou picos que superaram 100dB. O Hemograma se mostrou alterado, com redução de leucócitos, em 9 dos 16 participantes. Não houveram alterações nos demais exames. Concluiu-se que esta população apresentou desencadeamento de PAIR, dentro da normalidade. Os Níveis de Pressão Sonora se apresentaram acima do previsto em lei, e a maioria dos frentistas apresentaram leucopenia, o que pode estar relacionado à exposição aos solventes em questão. Tais conclusões mostram a importância de novos estudos voltados a este ambiente e a esta população. / By studying the causes of work-related hearing loss, usually noise-induced hearing loss is the most reported, although the literature points to other agents present in the workplace that can be harmful to workers health. The solvents are considered some of these agents and their effects on the auditory system are being investigated by some researchers. The industrial use of these solvents is vast and usually working conditions present in a large number of Brazilian industry expose workers to high concentrations of solvents. Living with chemicals nowadays is therefore mandatory and permanent is particularly important for workers involved in production processes that directly or indirectly use these substances because of damage to health and the environment that may result from its use. The risk and the danger that are related to chemicals must be worked in its various dimensions among which: the product of damage potential, environmental conditions and the work in which the activities are developed and the known history of that reality and other similar produced from epidemiological data and current scientific knowledge. This study assessed the audiological profile and characterized the attendants of desktop gas stations. Were used Conventional audiometry and high frequency, speech audiometry, tympanometry, otoacoustic emissions, the brainstem auditory evoked potential brainstem, clinical laboratory tests, and assessment of environmental noise. The recognition and analysis of the risks related to chemical agents are priority activities to qualify intervention in defense of workers\' health. The results were found thresholds within normal limits in all cases, however, they all showed the typical route of occupational hearing loss in evolution. The sound pressure levels varied between the posts, and the station 1 has not exceeded 80 dB, while the station 2 showed peaks which exceed 100dB. The blood count was abnormal, with leukocyte reduction in 9 of the 16 participants. There were no changes in other tests. It was concluded that this population presented onset of NIHL, normal. The sound pressure levels presented above provided by law, and most attendants showed leukopenia, which may be related to exposure to solvents in question. These findings show the importance of new studies related to this environment and this population.

Dans le système nerveux central, les monoamines modulent de nombreuses fonctions essentielles comme la locomotion, la motivation, la cognition, l’humeur et le sommeil. Le niveau extracellulaire de ces neurotransmetteurs est régulé par des transporteurs à haute affinité,cependant d’autres transporteurs, à faible affinité, peuvent contribuer à la recapture des monoamines, comme les transporteurs de cations organiques (OCT) et le transporteur plasmique des monoamines (PMAT). Récemment, l’implication des OCT dans différentes fonctions centrales, notamment le contrôle de l’humeur, la réponse au stress et aux antidépresseurs a été mise en évidence. Le rôle de PMAT dans le cerveau reste quant à lui encore peu caractérisé. Il transporte in vitro les monoamines, avec une préférence pour la dopamine et la sérotonine, avec des affinités submillimolaires. Ce transporteur est exprimé dans de nombreuses régions du cerveau humain et murin et dans différents types neuronaux. Par hybridation in situ fluorescente nous avons déterminé sa distribution cellulaire précise, dans des régions à fort niveau d’expression comme le complexe du cerveau antérieur basal (BFC) et des régions appartenant aux ganglions de la base comme le globus pallidus et la substance noire réticulée (SNr). Nous avons montré qu’il est fortement exprimé dans les neurones GABAergiques exprimant la parvalbumine, dans tous les interneurones cholinergiques dustriatum ainsi qu’une petite fraction des neurones cholinergiques du BFC. Il est également retrouvé dans certains noyaux monoaminergiques comme le locus coeruleus et les noyaux duraphé mais est absent des noyaux dopaminergiques, la substance noire compacte et l’aire tegmentale ventrale.Afin d’étudier sa fonction, nous avons exploité le système Cre-lox, approche couramment utilisée en biologie, en injectant un virus adéno-associé exprimant la recombinase Cre (AAVCre)dans la substance noire (SN) de souris comportant des allèles de PMAT floxés. Cette étude ne nous a pas permis de conclure quant à la fonction de PMAT dans la SN, mais nous a conduit à mettre en évidence une toxicité majeure de cet outil. Nous avons montré que l’injection d’AAV-Cre dans la SN entraine une perturbation anatomique et fonctionnelle des systèmes dopaminergiques et de la SNr, noyau de sortie des ganglions de la base, induisant des altérations comportementales importantes, avec une hyperlocomotion basale robuste et une insensibilité à la cocaïne, potentiellement par une action génotoxique.Nous avons également généré des souris invalidées constitutivement pour PMAT (PMAT-/-). Les tests comportementaux que nous avons commencés récemment nous ont révélé des altérations comportementales significatives chez ces souris de l’activité locomotrice dans un nouvel environnement ainsi que du niveau d’anxiété. Ces altérations pourraient résulter d'une perturbation des voies aminergiques en l’absence de PMAT. Nous poursuivrons cette étude par l'exploration d'autres aspects comportementaux ainsi que par l’évaluation des modifications neurochimiques engendrées par l'invalidation. Ces approches devraient fournir des pistes afin d’identifier les conséquences de l'absence de PMAT sur la signalisation aminergique, que l'on pourra explorer plus précisément par la suite sur le plan fonctionnel / High-affinity reuptake transporters exert a crucial role in the control of synaptic transmissionby ensuring the recycling of the released transmitters into the presynaptic terminals. Other typesof transporters such as Organic Cation Transporters (OCTs) and the Plasma MembranemonoAmine Transporter (PMAT), have been shown to transport, with low-affinity but highcapacity, aminergic neurotransmitters. While the role of OCTs in central nervous system hasbeen partially unraveled, the function of PMAT remains poorly characterized. In vitro, PMATtransports preferentially dopamine and serotonin and its expression is widespread in the brain,encompassing monoamine nuclei but also projection regions. In this study, we determined theprecise neuronal specificity of PMAT in several highly-expressing regions. We show that it isfound mostly in PV+ GABAergic neurons of basal forebrain and basal ganglia, in allcholinergic interneurons of the striatum and in some cholinergic neurons of basal forebraincomplex. These systems, highly regulated by monoamines, are important for locomotion,motivation, learning and wakefulness. Our result show that PMAT is located at a strategicposition to control the aminergic modulation of these integrated functions.To investigate the implication of PMAT in these regions, we used the Cre-lox technology, avalued and widely used approach for the study of gene function in vivo, injecting an adenoassociatedvirus expressing Cre recombinase in substantia nigra (SN) of mice in which PMATgene was floxed. In this study, we could not assess PMAT function in this SN but found thatAAV-CRE expression in this region produces major toxic effects. We showed that AAV-Creinjection in this region engenders a massive decrease of neuronal populations in both parscompacta and reticulata, leading to DA depletion in the nigrostriatal pathway. This wasassociated with a drastic behavioral phenotype with increased basal locomotor activity and lossof locomotor response to cocaine. Several hallmarks of Cre toxicity were found in SN of AAVCreinjected mice, including an increase of the DNA break markers. These observationsunderscore the need for careful control of Cre toxicity in the brain and reassessment of previous studies.To study the role of PMAT, we also generated PMAT knock out mice (PMAT-/-). Behavioralstudies that we just started have revealed significant impairments of locomotor activity in a newenvironment and anxiety level, supporting a possible disruption of monoaminergic systems inthese mice. On-going studies aim to explore other behaviors and search for eventualneurochemical changes provoked by PMAT invalidation. These experiments should providesome cues to understand which monoamines and circuits may be affected, that can beinvestigated functionnally and more specifically in a second step

Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that have been associated with a myriad of negative human health effects. These man-made compounds were used throughout most of the 20th century and although their intentional production has since been banned and their use limited to closed systems, their prevalence in the environment remains a factor in disease states for exposed populations. The worldwide levels of PCBs has been declining, however, there is evidence for renewed sources of these compounds. The presence of PCBs with lower numbers of chlorine atoms (LC-PCBs) have been verified as unintentional byproducts in paints and pigments, the decomposition of PCB waste, or the recycling or disposal attempts of PCB-laden materials. While exposure to the higher chlorinated congeners (HC-PCBs) is often attributed to the consumption of contaminated water or fatty animal meat, a significant route of exposure to the airborne LC-PCBs is through inhalation. These semi-volatile compounds have been detected in high quantities in both indoor and outdoor air in urban and rural communities, and their presence is pronounced in older buildings (e.g., homes and schools). When compared to HC-PCBs, LC-PCBs are more highly susceptible to metabolic transformations, and recently their sulfated metabolites have gained much interest. Although the sulfation of xenobiotics often is considered a route for their removal from the body, a previous study of Sprague-Dawley rats treated with 4-chlorobiphenyl (PCB 3) resulted in the substantial formation of sulfated metabolites (i.e., hydroxylation followed by sulfation of the LC-PCB). This metabolic route accounted for more than half of the treatment dose. Furthermore, LC-PCB sulfates have been shown to bind to the human serum protein, transthyretin, in vitro. Of the health effects associated with PCB exposure, neurotoxicity has been well established through various laboratory and epidemiological studies. It is proposed that the dopaminergic system lies at the core of the observed cognitive, motor, and intellectual dysfunction observed in exposed populations, especially in children exposed perinatally. Interestingly, PCB exposure has been linked to Parkinson's disease (PD) etiology, which is marked by a substantial loss of dopaminergic neurons. This thesis describes studies on the binding of selected LC-PCBs and their hydroxylated and sulfated metabolites to human serum albumin (HSA), the most abundant protein in human serum. The displacement of fluorescent probes, selective for the two major drug binding sites of HSA, indicates that LC-PCB sulfates generally bind to HSA with such affinity that is equal to or greater than that for the LC-PCBs or OH-LC-PCBs This work also included a study of the selective toxicity of these compounds to dopaminergic neuronal cells. The selective toxicity of these compounds was studied in a series of immortalized cell lines (i.e., two neuronal cell lines: the rat midbrain-derived N27 cell line, the human neuroblastoma-derived SH-SY5Y cell line, and the human liver-derived HepG2 cell line). The assessment of toxicity by MTT reduction and LDH release in these cellular models indicated that hydroxylated and sulfated metabolites of LC-PCBs exhibited toxicity that was selective to neuronal cells and, in most cases, selective for the dopaminergic neuronal cells. Furthermore, HPLC analysis of the distribution of the compounds from the extracellular medium into the cellular milieu indicated that the observed toxicity may be due in some cases to selective transport and further metabolism. This work contributes to understanding the neurotoxicity of LC-PCB hydroxylated and sulfated metabolites and the role that binding to serum proteins may play in it. Furthermore, it emphasizes the need for future studies on the effects that metabolism, particularly sulfation, may play in the disposition of LC-PCB congeners as it pertains to their metabolism, retention, and toxic effects.

In its latest neurotoxicity guidelines released by the US EPA Office of Prevention, Pesticides and Toxic Substances (OPPTS) in 1998, it is recommended that in a neurobehavioral testing, at a minimum, for acute studies, observations and activity testing should be made before the initiation of exposure, at the estimated TOPE (time of peak effects) within 8 hrs of dosing, and at 7 and 14 days after dosing. It is recommended that estimation of TOPE be made by dosing pairs of rats across a range of doses and making regular observations of gait and arousal. However it is well known that TOPE may vary with end points or exposure conditions. In order to derive quantitative safety measures such as the benchmark doses (BMD), dose-time-response modeling must be done first and a model-based estimate is then implied. In many cases, the overall BMD corresponds to a TOPE estimate. In such cases a substantial variation in the TOPE estimate in turn may result in substantial variation in BMD estimate. Therefore a reliable statistical estimate of TOPE is crucial to the correct determination of BMD. We therefore performed simulation studies to assess the impact of the experiment-based TOPE on the statistical estimation of the true TOPE on the basis of a fitted dose-time-response model. The simulation allows for the determination of the optimal timing range for the 2nd testing. The results indicated that given only four repeated observations, the optimal second testing time was at about midway between time zero and the true TOPE. Choosing the second testing time at the TOPE may not generate statistical estimates closer to the true TOPE.