El dolor es la primera causa de consulta al odontólogo. Por esto que es de suma importancia saber tratarlo correctamente para poder brindar a nuestros pacientes una solución eficaz a su problema. En las últimas décadas se ha centrado el estudio del dolor en animales mediante el uso de métodos algesiométricos que permitan evaluar el efecto antinociceptivo de distintos fármacos analgésicos y sus combinaciones. Un grupo de éstos son los analgésicos antiinflamatorios no esteroidales (AINEs) los cuales son ampliamente utilizados en el dolor, sin embargo, su uso conlleva una serie de efectos adversos que limitan su uso. Para contrarrestarlos, se han desarrollado combinaciones de fármacos que permitan aumentar los efectos analgésicos y disminuir las reacciones adversas. En este trabajo se estudian dos AINEs, paracetamol y meloxicam, para evaluar su interacción en el ensayo de dolor agudo térmico denominado tail-flick o test de la cola. Se utilizaron ratones de la cepa CF/1 a los que se le administró vía intraperitoneal, al tiempo del máximo efecto, las drogas en proporciones fijas de 1/2, 1/4, 1/8 y 1/16 de las DE25 de paracetamol y meloxicam, y mediante un análisis isobolográfico se determinó que la interacción, es de tipo supraaditiva o sinérgica. Se evaluó el efecto del sistema opioide por el pretramiento de los animales con el antagonista opioide, naltrexona, y se comprobó que no existe modificación de la naturaleza de la interacción. Los resultados obtenidos en este trabajo demuestran que existe un efecto sinérgico en la actividad antinociceptiva que desarrollan el paracetamol y meloxicam al administrarlos conjuntamente, y que el sistema opioide no modifica esta interacción. Estos hallazgos, son de relevancia para el desarrollo de nuevas asociaciones de fármacos que produzcan mayor analgesia con los menores efectos tóxicos, lo que sin duda es un área prometedora en el estudio del tratamiento farmacológico del dolor.

Chronic arthritis adversely affects glomerular function and nonsteroidal anti-inflammatory drugs (NSAIDs) reduce electrolyte urinary excretion. In addition, both acute and chronic inflammations may alter clearance of drugs. We studied (a) the effects of inflammation on the renal function and pharmacokinetics of rofecoxib and meloxicam; (b) whether inflammation could exacerbate reduced electrolytes excretion changes observed with NSAIDs; and (c) the influence of inflammation on distribution of these drugs into the kidney. Single oral doses of rofecoxib (10 mg kg-1), meloxicam (3 mg kg -1) or placebo were administered to normal or pre-adjuvant arthritic rats. Blood and urine samples were collected for the measurement of plasma nitrite, BUN and creatinine. The urinary excretion of sodium and potassium was also determined. Nitrite, BUN and plasma creatinine were increased starting on day 9 in the groups with inflammation. Sodium and potassium excretion rates were not affected by inflammation. Meloxicam did not alter the electrolyte excretion in any of the groups. Rofecoxib significantly decreased sodium and potassium excretion in normal rats and potassium excretion in inflamed rats. Inflammation significantly increased plasma concentrations of rofecoxib, but not meloxicam. The ratios of the kidney:plasma concentrations were not significantly altered by inflammation following either drug. Inflammation altered kidney function, demonstrated by increases in BUN and plasma creatinine. However, it did not influence the urinary electrolytes excretion. Since we have observed similar patterns of the effect of NSAIDs on kidney under healthy and inflammatory conditions, one may conclude that inflammation does not exacerbate the adverse effect.

La vía de administración oral de fármacos es la más utilizada para lograr efectos sistémicos. Aproximadamente el 90% de todos los fármacos utilizados para este fin son administrados por esa vía. La respuesta terapéutica de un fármaco depende normalmente de una concentración adecuada del mismo, la cual se debe alcanzar y mantener en el sitio de acción. Numerosos principios activos de interés fármacoterapéutico presentan baja biodisponibilidad oral, debido principalmente a su baja solubilidad acuosa, entre los cuales se encuentra el Meloxicam, un antiinflamatorio no esteroideo usado en el tratamiento de la osteoartritis y otras enfermedades articulares. Posee mejor tolerancia gástrica disminuyendo las reacciones adversas frente a otros antinflamatorios motivo por el cual se utiliza con mayor frecuencia en patologías crónicas. Para poder mejorar su biodisponibilidad oral, en esta tesis se planteó la utilización de Dispersiones Sólidas como una estrategia farmacotécnica para mejorar la velocidad de disolución del fármaco. En el capítulo I se realiza una introducción sobre la importancia de las propiedades de los fármacos frente a su biodisponibilidad oral. Se describen las características de las Dispersiones Sólidas, del Meloxicam y del Poloxamer 188 utilizado para su obtención. Se incluye una extensa revisión bibliográfica que respalda el trabajo. En el Capítulo II se presentan todos los materiales utilizados en las distintas etapas de desarrollo. Asimismo, se exponen las técnicas empleadas para caracterizar las muestras obtenidas y los métodos utilizados en su obtención. En el Capítulo III se detalla la obtención de las Dispersiones Sólidas por el método de fusión. Se presentan las caracterizaciones fisicoquímicas, farmacéuticas y fisicomecánicas de las mismas y su comparación con las Mezclas Físicas obtenidas de ambos componentes en iguales proporciones. A partir de los datos obtenidos se sacan las conclusiones. En el capítulo IV se detalla la obtención de las Dispersiones Sólidas por el método de Atomización que incluye una introducción bibliografía. Se explican los pasos seguidos para seleccionar las condiciones operativas óptimas para el método teniendo en cuenta las características de los compuestos utilizados. Se detallan las caracterizaciones fisicoquímicas y farmacéuticas comparando estos resultados con muestras obtenidas por el método de fusión. Además se describe la incorporación de las muestras obtenidas en la Forma Farmacéutica Cápsulas comparando los perfiles de disolución con otra del Mercado Farmacéutico. Por último se discuten los resultados obtenidos y se presentan las conclusiones correspondientes. En el Capítulo V a partir de las conclusiones parciales se presentan las conclusiones generales de esta tesis, junto a los principales aspectos a considerar en trabajos futuros. / Oral drug administration is the most frequently used method to attain systemic effects. Approximately 90% of all drugs are orally administered. The therapeutic response to a drug usually depends on its correct concentration, which must be achieved and maintained in the action site. Numerous active pharmaceutical ingredients (API) show low oral bioavailability mainly due to their low solubility in water, such as Meloxicam. Meloxicam is a non-steroid anti-inflammatory used in the treatments for osteoarthritis and other joint disorders. Meloxicam has a better gastric tolerance decreasing adverse reactions compared to other anti-inflammatory drugs, which is why it is more widely used for treating chronic pathologies. In order to improve its oral bioavailability, this thesis poses solid dispersions as a technological strategy to improve the drug’s dissolution rate. On chapter I there is an introduction about the importance of drug properties against its oral bioavailability. The features/characteristics of the various types of solid dispersions and the methods used to obtain them are described on this chapter as well. In addition, properties of Meloxicam and Poloxamer 188 (a polymer used in formulations) are presented. An extensive bibliographic review is included. On chapter II all the materials used during the various stages of development are presented. Additionally, the techniques applied to characterize the obtained samples as well as the obtention methods are described. Chapter III details the development of Meloxicam-Poloxamer solid dispersions through the fusion/solidification method. Their physicochemical, pharmaceutical and physicomechanical characterizations are presented and analyzed. In addition, a comparison with the corresponding physical mixtures is given. From the collected data it can be concluded that the increase of the drug’s rate dissolution from solid dispersions is due to the humectant effect of Poloxamer. Chapter IV describes the development of solid dispersions through spray drying and also includes a bibliographical review. The steps that were followed to select optimum operating conditions are explained, considering the specific features of the system Meloxicam-Poloxamer and the challenge of working at low temperatures without organic solvents. The physico-chemical and pharmaceutical characterizations are detailed, comparing these results to those of the samples obtained through the fusion method. In addition, the incorporation of the obtained solid dispersions under the pharmaceutical form “capsules” is described, contrasting the dissolution profiles against other capsule formulations available in the pharmaceutical market. Finally, the results are discussed. It is concluded that the solid dispersions obtained through spray drying enhance even more Meloxicam’s dissolution rate due to the carrier’s humectant effect and the decrease in particle size. The same behavior is observed for the formulations added in the prepared capsules. On chapter V and from the partial conclusions, general conclusions of this thesis are presented along with the main aspects to be considered in future works.

Animal behavior can be used to detect disease and well-being in dairy cattle. In this dissertation, we evaluated the accuracy of an accelerometer to measure step activity, lying time, and lying bouts in pre-weaned dairy calves. The output from the accelerometer was correlated with behavioral measurements taken from video footage. The accelerometer proved to be accurate in identifying step activity (r = 0.99), lying time (r = 0.99), and lying bouts (r = 0.99). The accelerometer was then used to detect behavioral changes occurring around respiratory disease events in pre-weaned calves. Activity declined 1 d prior to clinical disease onset, and this decline persisted for 3 d post-diagnosis. Furthermore, lying bouts declined beginning 2 d prior to diagnosis, and this effect persisted after diagnosis as well. However, aside from a slight reduction in milk intake, feeding behavior was not different between diseased and healthy calves. These data suggest that activity and lying behaviors may be a better measure than feeding behaviors for detection of respiratory disease in pre-weaned dairy calves. Dystocia has detrimental effects on both periparturient dairy cows and newborn calves. We administered a non-steroidal anti-inflammatory drug, meloxicam to periparturient dairy cattle. Treatments included administration prior to calving (MEL-PRE, n = 60), post-calving (MEL-POST, n = 69), or a negative control (CTL, n = 65). We measured the length of labor to determine which cows had easy or difficult calvings. Eutocic MEL-PRE animals produced 6.8 kg/d more milk than eutocic CTL. Regardless of calving difficulty, MEL-PRE animals produced more milk fat, protein, and lactose (kg/d) than the CTL. Additional research is needed to determine appropriate treatments for dystocic calvings. Calves born during the above trial were monitored to determine if meloxicam administration prior to calving impacted newborn calf health and behavior. Calves born difficultly displayed fewer lying bouts for the first few days after birth when compared to calves born easily. No effect of treatment or calving difficulty was noted on calf health. Additional research examining intervention strategies aimed at improving well-being of calves born difficultly is needed. / Ph. D. / Public interest in animal welfare continues to grow, making it increasingly important that the dairy industry evaluates management practices to further advance animal well-being. Animal behavior can be used to detect disease and well-being in dairy cattle. We monitored activity and lying behaviors around respiratory disease events in calves. This was done to determine which behaviors were altered by respiratory disease, and if these behaviors could be used to detect respiratory disease events earlier. Activity and lying behaviors were measured using an accelerometer that works similarly to a pedometer. We were able to identify that calves that would manifest with respiratory disease would display a decline in activity prior to clinical disease diagnosis. These data suggest that activity measures could be a promising indicator for respiratory disease detection in calves, and allow for earlier detection. Parturition, the act of a dairy cow giving birth, is a stressful, risky time period as disease incidences and death are high. Furthermore, an immense amount of inflammation occurs after calving due to parturition as well as metabolic stress associated with milk production. Therefore, in this study, we administered a non-steroidal anti-inflammatory drug (meloxicam) to alleviate inflammation. Treatments included administration prior to calving (MEL-PRE), post-calving (MEL-POST), or a negative control (CTL). We measured the length of labor to determine which cows had easy or difficult calving events. Animals that received meloxicam prior to calving and calved easily produced 6.8 kg/d more milk than CTL animals that calved easily. Additional research is needed to determine appropriate treatments for animals that calve difficultly. Calves born during the above trial were monitored to determine if meloxicam administration prior to calving impacted newborn calf health and behavior. No effect of treatment or calving difficulty was noted on calf health. Additional research examining intervention strategies aimed at improving well-being of calves born difficultly is needed.

O sistema imune do hospedeiro acometido pela doença de Chagas tem sido alvo de importantes pesquisas que podem favorecer avanços no entendimento dos mecanismos patogênicos relacionados à doença. No presente estudo, investigamos possíveis ações benéficas provenientes de efeitos anti-inflamatórios e antioxidantes da associação terapêutica (melatonina/meloxicam) sobre a cardiomiopatia chagásica crônica. Foram analisadas citocinas e outros mediadores envolvidos no processo inflamatório característico da infecção. Além disso, níveis plasmáticos de Creatina Fosfoquinase MB (CK-MB), número de focos inflamatórios no tecido cardíaco e análise do peso relativo do coração foram avaliados como fatores preditivos da redução dos danos no miocárdio após os diferentes tratamentos. Como modelo experimental, foram utilizados ratos wistar infectados pela cepa Y de T. cruzi e tratados ou não com melatonina, meloxicam, ou associação de ambos. As células inflamatórias e o parasitismo tecidual cardíaco foram avaliados por meio de técnica histológica. A técnica ELISA foi utilizada para detecção e quantificação de citocinas pró-inflamatórias e modulatórias no miocárdio e nos soros dos animais experimentais. Também foram investigados os níveis de nitrito produzidos por macrófagos e por células cardíacas dos grupos experimentais pela reação de Griess. Os parâmetros foram investigados durante a fase: crônica (90, 120 e 180) dias após a infecção. O estudo poderá contribuir para um melhor entendimento das respostas imunológicas anti-T. cruzi, bem como da patogenia da disfunção cardíaca chagásica crônica. / The host immune system affected by Chagas disease has been the subject of important research that can promote advances in the understanding the pathogenic mechanisms related to the disease. In the present study, it was investigated the possible beneficial actions of the anti-inflammatory and antioxidant combination therapy (melatonin / meloxicam) on chronic Chagas cardiomyopathy. Some cytokines and other mediators involved in the inflammatory process characteristic of infection were analyzed. In addition, plasma levels of creatine phosphokinase MB (CK-MB), number of inflammatory foci in the cardiac tissue and analysis of the relative weight of the heart were evaluated as predictors of damage reduction in the myocardium after different treatments. As experimental model, we used Wistar rats infected with the Y strain of T. cruzi. Some groups were untreated and others treated with melatonin, meloxicam, or combination of both. Inflammatory cells and heart tissue parasitism were evaluated by histological technique. Some pro-inflammatory and modulatory cytokines were quantified by ELISA technique in the myocardium and serum from experimental animals. The production of nitrite by macrophages and cardiac cells of the experimental groups was also investigated through Griess reaction. The parameters were observed during the chronic stage: (90, 120, and 180) days after infection. The study may contribute to a better understanding of the anti-T. cruzi immunological responses, as well as the pathogenesis of chronic Chagas heart dysfunction.

Os AINE\'s são frequentemente empregados para o tratamento da dor aguda em gatos, porém, podem ser contraindicados pela propensão em causar efeitos adversos. A dipirona é um antigo analgésico não-opioide extensamente utilizado cujo mecanismo de ação ainda não foi completamente elucidado. O presente estudo prospectivo, randomizado e cego teve como objetivo avaliar o efeito analgésico e o mecanismo de ação via cicloxigenases (COX-1 e 2) da administração por via intravenosa (IV) de dipirona (12,5 mg/kg a cada 12 horas D12,5 ou 25 mg/kg a cada 24 horas D25) ou de meloxicam (0,1 mg/kg a cada 24 horas M) em gatas submetidas à ovariosalpingohisterectomia (OSH) eletiva. Trinta gatas (13 ± 5 meses e 2,7 ± 0,5 kg) foram avaliadas durante 24 horas após o início do tratamento a partir de ferramentas objetivas e subjetivas da dor. Medicação resgate com cloridrato de tramadol (2 mg/kg, IV) foi instituída quando escores ≥ 5 pela Escala Glasgow. A atividade das COX-1 e 2 foi avaliada a partir da mensuração das concentrações de tromboxano B2 (TXB2) e prostaglandina E2 (PGE2). Efeitos adversos foram registrados e exames laboratoriais, incluindo concentrações séricas de dimetilarginina simétrica (SDMA), foram realizados. As análises estatísticas foram efetuadas com o software GraphPad Prism versão 7.03. O grau de significância estabelecido para os testes foi de 5% (P < 0,05). Mudanças nos parâmetros fisiológicos cardiovasculares não foram clinicamente relevantes, porém as gatas do grupo M apresentaram aumento de frequência cardíaca em relação ao basal (P = 0,0331). A temperatura retal reduziu no momento T1h em todos os grupos (P = 0,0001). Houve um aumento da glicemia no momento T4h no grupo D25 (P = 0,0178) e em T1h no grupo M (P = 0,0205). Apesar de os escores de dor e sedação 9 não diferirem entre grupos, a escala analógica visual revelou aumento em T4h em relação ao basal no D12,5 (P = 0,0415) e os escores de sedação em T1h foram superiores ao basal em todos os tratamentos (P < 0,0001). Não houve diferença quanto ao resgate analgésico, porém duas gatas dos grupos D12,5 (20%) e M (20%) e quatro do D25 necessitaram de medicação resgate. As concentrações de TXB2 foram superiores no grupo M em relação ao D12,5 e D25 em T4h (P = 0,0032 e P < 0,0001, respectivamente) e T24h (P = 0,0070 e 0,0111, respectivamente). Houve redução muito significativa em T1/2h, T4h e T24h quando comparados ao T0h em todos os grupos (P < 0.0001) e ocorreu aumento entre T1/2h e T4h no grupo M (P = 0,0004). As concentrações de PGE2 estimulada por lipopolisacarídeos (LPS) foram superiores em D25 em relação ao M em T4h (P = 0,0479). No grupo D12,5, em T1/2h, esta foram inferiores as de T0h (P = 0,0001) e T4h (P = 0,0112). O mesmo ocorreu no grupo D25 em T0h, T4h e T24h (P < 0,0001, P = 0,001 e 0,0004, respectivamente) enquanto que no M, os momentos T1/2h e T4h apresentaram valores inferiores ao T0h (P = 0,0016 e 0,0075). As concentrações séricas de SDMA do grupo D25 reduziram em T24h quando comparadas as de T0h (P = 0,0322), porém apenas uma gata do grupo M apresentou concentração acima do limite para a espécie. A partir dos resultados observados conclui-se que os protocolos analgésicos instituídos foram efetivos para o controle da dor pós-operatória neste contexto, apresentando inibição não seletiva COX-2 sem causar efeitos adversos e alterações hematológicas, na atividade das enzimas hepáticas e na taxa de filtração glomerular. / NSAIDs are often used for treatment of acute pain in cats, but it may be contraindicated for propensity to cause adverse effects. Dipyrone ia a widely used non-opioid analgesic whose mechanism of action has not yet been fully elucidated. The present prospective, randomized, blind study aimed to evaluate the analgesic effect and mechanism of action of inhibition of cycloxigenases (COX-1 and 2) of intravenous (IV) administration of dipyrone (25 mg/kg q 24 hours or 12.5 mg/kg q 12 hours) or meloxicam (0.1 mg/kg q 24 hours) in cats underwent elective ovariohysterectomy. Thirty cats (13 ± 5 months and 2,7 ± 0,5 kg) were evaluated for 24 hours after surgical procedure using objective and subjective pain tools. Rescue medication with tramadol hydrochloride (2 mg/kg IV) was administrated when scores ≥ 5 by the Glasgow scale. The activity of COX-1 and 2 was assessed by measuring the concentrations of thromboxane B2 (TXB2) and prostaglandin E2 (PGE2). Adverse effects were recorded and laboratory tests, including serum concentrations of symmetrical dimethylarginine (SDMA), were performed. Data was analyzed with GraphPad Prism version 7.03. Values of P < 0.05 were considered significant. Changes in cardiovascular parameters were not clinically relevant, but the M group presented higher heart rate than basal (P = 0.0331). The rectal temperature reduced at time T1h in all groups (P = 0.0001). There was an increase in blood glucose at time T4h in group D25 (P = 0.0178) and in T1h in group M (P = 0.0205). Although pain and sedation scores did not differ between groups, the visual analogue scale 11 showed an increase in T4h over baseline in D12.5 (P = 0.0415) and sedation scores in T1h were higher than baseline in all treatments (P < 0.0001). There was no difference in the analgesic rescue, but two cats of D12.5 (20%) and M (20%) groups and four from the D25 required rescue medication. The concentrations of TXB2 were higher in M group compared to D12.5 and D25 at T4h (P = 0.0032 and P < 0.0001, respectively) and T24h (P = 0.0070 and 0.0111, respectively) and there was a very significant reduction in T1/2h, T4h and T24h when compared to T0h in all groups (P < 0.0001) and there was an increase between T1/2h and T4h in group M (P = 0.0004). Concentrations of lipopolysaccharide-stimulated PGE2 (LPS) were higher in D25 compared to M in T4h (P = 0.0479). Those in the D12.5 group, in T1/2h, were lower than in T0h (P = 0.0001) and T4h (P = 0.0112). The same occurred in group D25 at T0h, T4h and T24h (P <0.0001, P = 0.001 and 0.0004, respectively) whereas in M, T1/2h and T4h moments presented values lower than T0h (P = 0.0016 and 0.0075). Serum concentrations of SDMA of D25 group decreased in T24h when compared to T0h (P = 0.0322) and only one cat (group M) showed serum concentration above the feline cut-off. In conclusion, the analgesic protocols were effective for the control of postoperative pain in this context, presenting COX-2 non-selective inhibition without causing adverse effects and hematological, liver enzyme activity and glomerular filtration rate alterations.

A modulação das respostas imunológicas em modelos experimentais infectados por Trypanosoma cruzi tem contribuído de maneira importante nas investigações de novas terapias contra a doença de Chagas. Neste estudo, avaliamos a produção de citocinas Th1 e Th2 relevantes na fase aguda da doença, assim como, níveis de prostaglandina E2, nitrito, parasitemia sanguínea e parasitemia tecidual cardíaca em ratos Wistar machos infectados pela cepa Y de T. cruzi. Foram investigados nos 7°, 14° e 21° dias de infecção, as citocinas padrão Th1: IL-2, IFN-, TNF- e padrão Th2: IL-4, IL-10. Os parâmetros foram dosados e interpretados após a administração, ou não, de meloxicam, melatonina ou ambos. A administração de melatonina contribuiu na proteção do hospedeiro submetido à infecção experimental por T. cruzi devido às ações imunomodulatórias previamente atribuídas a esta substância. O bloqueio da síntese de PGE2 atribuído à administração de meloxicam e/ou melatonina durante a fase aguda da infecção foi seguido por uma modulação de citocinas pertencentes aos padrões Th-1 e Th-2. Houve um aumento da síntese de citocinas importantes na proteção do hospedeiro durante a fase aguda da infecção, tais como IFN-, IL-2 e NO. Estes efeitos demonstrados no estudo foram benéficos, sendo evidenciados pela diminuição da carga parasitária dos animais experimentais. Os resultados poderão auxiliar a estabelecer mecanismos alternativos de tratamento na infecção chagásica aguda através de um melhor entendimento das respostas imunológicas anti-T cruzi. / The modulation of the immune responses in experimental models infected with Trypanosoma cruzi has effectively contributed for the investigations of new therapies used to treat Chagas disease. In this study, it was evaluated the production of Th1 and Th2 cytokines, which play a role during the acute phase of the disease, as well as prostaglandin E2 and nitrite, number of blood parasites and cardiac tissue parasitism in male Wistar rats infected with the Y strain of T. cruzi. Experiments were performed on 7, 14 and 21 days after infection in which Th1 cytokines such IL-2, IFN-, TNF- were done and Th2 cytokines as IL-4 and IL-10. The parameters were evaluated with/without the administration of meloxicam, melatonin or both. Melatonin contributed for the hosts protection in animals experimentally infected with T. cruzi through its immunomodulator actions. The blockage of PGE2 synthesis was attributed to the administration of meloxicam and/or melatonin during the acute phase of infection, followed by a modulation of the Th1 and Th2 cytokines. In this work enhanced levels of IFN-, IL-2 and NO were observed. The analysis of these data was beneficial for the hosts protection through a reduced number of amastigote nests in heart tissue. These results permit to establish alternative mechanisms to treat the acute chagasic infection through a better understanding of the immune responses against T cruzi.

O sistema imune do hospedeiro acometido pela doença de Chagas tem sido alvo de importantes pesquisas que podem favorecer avanços no entendimento dos mecanismos patogênicos relacionados à doença. No presente estudo, investigamos possíveis ações benéficas provenientes de efeitos anti-inflamatórios e antioxidantes da associação terapêutica (melatonina/meloxicam) sobre a cardiomiopatia chagásica crônica. Foram analisadas citocinas e outros mediadores envolvidos no processo inflamatório característico da infecção. Além disso, níveis plasmáticos de Creatina Fosfoquinase MB (CK-MB), número de focos inflamatórios no tecido cardíaco e análise do peso relativo do coração foram avaliados como fatores preditivos da redução dos danos no miocárdio após os diferentes tratamentos. Como modelo experimental, foram utilizados ratos wistar infectados pela cepa Y de T. cruzi e tratados ou não com melatonina, meloxicam, ou associação de ambos. As células inflamatórias e o parasitismo tecidual cardíaco foram avaliados por meio de técnica histológica. A técnica ELISA foi utilizada para detecção e quantificação de citocinas pró-inflamatórias e modulatórias no miocárdio e nos soros dos animais experimentais. Também foram investigados os níveis de nitrito produzidos por macrófagos e por células cardíacas dos grupos experimentais pela reação de Griess. Os parâmetros foram investigados durante a fase: crônica (90, 120 e 180) dias após a infecção. O estudo poderá contribuir para um melhor entendimento das respostas imunológicas anti-T. cruzi, bem como da patogenia da disfunção cardíaca chagásica crônica. / The host immune system affected by Chagas disease has been the subject of important research that can promote advances in the understanding the pathogenic mechanisms related to the disease. In the present study, it was investigated the possible beneficial actions of the anti-inflammatory and antioxidant combination therapy (melatonin / meloxicam) on chronic Chagas cardiomyopathy. Some cytokines and other mediators involved in the inflammatory process characteristic of infection were analyzed. In addition, plasma levels of creatine phosphokinase MB (CK-MB), number of inflammatory foci in the cardiac tissue and analysis of the relative weight of the heart were evaluated as predictors of damage reduction in the myocardium after different treatments. As experimental model, we used Wistar rats infected with the Y strain of T. cruzi. Some groups were untreated and others treated with melatonin, meloxicam, or combination of both. Inflammatory cells and heart tissue parasitism were evaluated by histological technique. Some pro-inflammatory and modulatory cytokines were quantified by ELISA technique in the myocardium and serum from experimental animals. The production of nitrite by macrophages and cardiac cells of the experimental groups was also investigated through Griess reaction. The parameters were observed during the chronic stage: (90, 120, and 180) days after infection. The study may contribute to a better understanding of the anti-T. cruzi immunological responses, as well as the pathogenesis of chronic Chagas heart dysfunction.

Made available in DSpace on 2018-06-27T18:56:28Z (GMT). No. of bitstreams: 2 Katia Nascimento.pdf: 1068792 bytes, checksum: 21eda0227fa806a032831389e9702cbc (MD5) Katia Nascimento.pdf.jpg: 3573 bytes, checksum: 0598575e3e40c135c5f6a495204e1f7e (MD5) Previous issue date: 2013-08-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The toxicological sciences cover several areas including the toxicology, which studies the toxicity of nanoparticles (NPs) for use in the biological contact. NPs depending on how they interact with the cells can generate a series of imbalances, may be both cell membrane or in genetic material. This study evaluated the cytotoxicity and oxidative stress of nanocapsules (NCs) of meloxicam in cultured splenocytes of mice in vitro. We used mice of Balb/ c spleens were removed for the experiments. Cytotoxicity assays were performed as the 3 - (4,5) dimetiltialzolil -2,5 diphenyltetrazolium (MTT) and PicoGreen®, and also oxidative stress through the levels of thiobarbituric acid reactive species (TBARS), catalase activity and the levels of non-protein thiols (NPSH). The results showed that both NCs meloxicam (MN) NCs white (NB) and free meloxicam (ML) were cytotoxic to splenocytes. MF increased lipid peroxidation, but did not change antioxidant defenses, while MN did not alter the oxidative stress parameters. The NC constituents were isolated and it was performed cytotoxicity assays in splenocytes of mice. We demonstrated that all components (PCL, Tween 80, Span 60 and oil - medium chain triglyceride) caused cytotoxicity and only the PCL and Tween 80 caused damage to the nuclear membrane. Therefore, we can conclude that NC, NB and MF caused cytotoxicity, but only NB and MF produced oxidative stress. Moreover, cytotoxic effects of NCs constituents isolated did not intense. In this context, this study revealed that the NC components act synergistically to cause toxicity. / As ciências toxicológicas abrangem várias áreas entre elas, a nanotoxicologia, a qual estuda a toxicidade de nanopartículas (NPs) destinadas ao contato biológico. As NPs dependendo da maneira como interagem com as células, podem gerar uma série de desequilíbrios, podendo ser tanto a nível de membrana celular ou ainda, no material genético. Neste estudo foram avaliados a citotoxicidade e o estresse oxidativo de nanocápsulas (NCs) de meloxicam em cultura de esplenócitos de camundongos in vitro. Foram utilizados camundongos da linhagem Balb/c e os baços foram removidos para a realização dos experimentos. Foram realizados ensaios de citotoxicidade como do 3-(4,5) dimetiltialzolil (4,5) dimetiltialzolil (4,5) dimetiltialzolil (4,5) dimetiltialzolil (4,5) dimetiltialzolil (4,5) dimetiltialzolil (4,5) dimetiltialzolil (4,5) dimetiltialzolil (4,5) dimetiltialzolil (4,5) dimetiltialzolil -2,5 difeniltetrazólio 2,5 difeniltetrazólio 2,5 difeniltetrazólio 2,5 difeniltetrazólio2,5 difeniltetrazólio2,5 difeniltetrazólio 2,5 difeniltetrazólio2,5 difeniltetrazólio 2,5 difeniltetrazólio (MTT) e PicoGreen®, e ainda, de estresse oxidativo através dos níveis de espécies reativas ao ácido tiobarbitúrico (TBARS), atividade da catalase e os níveis de tióis não-proteicos (NPSH). Os resultados demonstraram que as tanto as NCs de meloxicam (MN), NCs brancas (NB) e meloxicam livre (ML) foram citotóxicas aos esplenócitos. A NB causou um aumento nos níveis de TBARS, indicando uma peroxidação lipídica na membrana celular, e um aumento na atividade da catalase. ML causou somente um aumento na peroxidação lipídica sem alterar as defesas antioxidantes, enquanto MN não causou alteração nos parâmetros de estresse oxidativo avaliados. Os constituintes da NC foram isolados e realizados ensaios de citotoxicidade. Como resultados, foi observado que todos os componentes (PCL, Tween 80, Span 60 e óleo triglicerídeo de cadeia média) causaram citotoxicidade e apenas o PCL e Tween 80 lesaram a membrana nuclear. Portanto, pode-se concluir que tanto MN, NB e ML causaram uma citotoxicidade, porém somente as NB e o ML causaram estresse oxidativo. Além disso, o efeito citotóxico dos componentes das NCs isoladamente não foi tão intenso, portanto este estudo revelou que os componentes das NCs atuam sinergicamente para desencadear a toxicidade.

Submitted by MARCIA ROVADOSCHI (marciar@unifra.br) on 2018-08-16T14:21:31Z No. of bitstreams: 2 Dissertacao_BenonioTerraVillalba.pdf: 1084592 bytes, checksum: 26793415e5a9f5705ffceb4c83839d5d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-08-16T14:21:31Z (GMT). No. of bitstreams: 2 Dissertacao_BenonioTerraVillalba.pdf: 1084592 bytes, checksum: 26793415e5a9f5705ffceb4c83839d5d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2011-12-02 / The present study investigated the time-course of antinociceptive effect of meloxicam-loaded nanocapsules (M-NC) (5 mg/kg, intragastrically (i.g.) in chemical and thermal models of pain in mice. The antinociceptive activity of M-NC was compared to free meloxicam (M-F) (5 mg/kg, i.g.). Experiments were carried out in male Swiss mice previously treated with M-NC or M-F or suspension without drug (B-MC), at different times (0.5 – 120 h). M-NC elicited a significant increase in the tail-immersion and hot-plate response latency and this effect remained significant up to 24 h. Antinociceptive action of M-NC in the thermal test was similar to M-F. M-NC reduced the acetic acid-induced abdominal writhing up to 48 h, while M-F produced an inhibition to 24 h. Pre-treatment up to 96 h with M-NC produced a marked reduction of the licking time in the first and second phases in the formalin test, while M-F had significant effect against the duration of licking up to 24 h in the first phase and at 0.5 h in the second phase. Paw oedema formation induced by formalin was reduced up to 96 h of pre-treatment with M-NC, while M-F had no significant effect against the formation of the paw oedema. Pre-treatment of up to 72 h with M-NC produced a marked reduction of the licking time and paw oedema formation induced by glutamate, while M-F had significant effect in both parameters up to 24 h. The antiedematogenic effect of M-NC remained significant up to 96 h after the administration, while M-F produced an inhibition of ear oedema up to 24 h. In conclusion, time-curse of antinociceptive effect indicated that M-NC exhibited more prolonged action than M-F. Thus, M-NC may be of potential interest in developing new prolongated delivery systems for the treatment of pain. / O presente estudo investigou o tempo de duração do efeito antinociceptivo de nanocápsulas com meloxicam (M-NC) (5 mg / kg, por via intragástrica (ig)) em modelos químicos e térmicos de dor em camundongos. Além disso, a atividade antinociceptiva das M-NC foi comparada com a do meloxicam na forma livre (MF) (5 mg / kg,ig). Foram utilizados camundongos machos da linhagem Swiss previamente tratados com M-NC ou MF ou com uma suspensão sem o fármaco (B-MC), em diferentes tempos (0,5 - 120 h). As M-NC provocaram um aumento significativo na latência de resposta nos testes de imersão da cauda e placa quente e este efeito permaneceu até 24 h. A ação antinociceptiva das M-NC nos testes térmicos foi semelhante ao MF. As M-NC reduziram as contorções abdominais induzidas pelo ácido acético em até 48 h, enquanto o MF produziu uma inibição apenas até 24 h. O pré-tratamento de até 96 h com as M-NC produziu uma redução acentuada do tempo de lambida na primeira e segunda fases do teste da formalina, enquanto o MF teve efeito significativo contra a duração do tempo de lambida em até 24h na primeira fase e em 0,5 h, na segunda fase. A formação do edema de pata induzido pela formalina foi reduzido até 96 h de pré-tratamento com as M-NC, enquanto o MF não teve efeito significativo contra a formação do edema de pata. O pré-tratamento de até 72 h com as M-NC produziu uma redução acentuada do tempo de lambida e na formação de edema de pata induzido pelo glutamato, enquanto o MF teve efeito significativo em ambos os parâmetros em até 24h. O efeito antiedematogênico das M-NC permaneceu significativo até 96 h após a administração, enquanto o MF produziu uma inibição no edema de orelha até 24 h. Em conclusão, o tempo de duração do efeito antinociceptivo indicou que as M-NC exibiram uma ação mais prolongada do que o MF. Assim, as M-NC podem ser de interesse potencial no desenvolvimento de novos sistemas de liberação para o tratamento da dor.