No description available.

O sulindaco é um antiinflamatório não esteroidal (AINE) classificado quimicamente como ácido carboxílico, da classe dos acetatos, que inibe de forma não seletiva a cicloxigenase 1 e 2. Terapeuticamente, é utilizado como agente analgésico e antiinflamatório para o tratamento de sintomas da artrite reumatóide aguda e crônica, osteoartrite e espondilite anquilosante, no entanto, seu uso não está restringido somente a estas patologias, pois apresenta atividade quimiopreventiva, sendo atualmente também utilizado para este fim, apesar de inúmeros relatos de toxicidade gastrointestinal e hepática terem sido relatados na literatura. Ele é ingerido como um pró-fármaco, e por reações de biotransformação hepática origina um metabólito reduzido (sulindaco sulfeto, ativo farmacologicamente) e outro oxidado (sulindaco sulfona, inativo). Para avaliar os efeitos do sulindaco e seus metabólitos, foram realizados estudos in vitro em mitocôndrias isoladas de fígado de rato, para explorar aspectos mecanísticos de toxicidade mitocondrial, e ensaios com linhagem celular de hepatoma humano HepG2, para avaliar seus efeitos após metabolização, uma vez que estas células mantém enzimas responsáveis pelas reações de biotransformação de fase I e II. Nossos resultados demonstram que o sulindaco sulfeto estimula a respiração de estado 4 e promove a liberação de cálcio pré-acumulado pela organela de maneira concentração-dependente, sendo evidente o efeito desacoplador sobre a fosforilação oxidativa, refletidos na diminuição da viabilidade celular em associação com a diminuição do conteúdo de ATP, provocado pela dissipação do potencial de membrana mitocondrial, sugerindo um mecanismo protonoforético de desacoplamento, responsável pela toxicidade deste antiinflamatório. Além disso, foi observado o inchamento das mitocôndrias em meio energizado, condição que ocorre independente de cálcio presente no meio reacional. Este evento foi parcialmente sensível a ciclosporina A e Mg2+, teve prevenção total com a adição de BHT e insensibilidade a outros moduladores, como ADP, ATP, DTT e NEM. Os resultados não condizem com a transição de permeabilidade mitocondrial clássica, uma vez que é dependente de cálcio, e o mecanismo de prevenção deste efeito obtida com a adição de BHT é desconhecido, pois não foi observada a indução de formação de radicais livres nos dois modelos experimentais utilizados. No entanto, a indução de intumescimento mitocondrial pode contribuir para seus efeitos tóxicos. O sulindaco e o sulindaco sulfona não apresentaram quaisquer efeitos descritos para o sulindaco sulfeto, indicando que somente o metabólito farmacologicamente ativo é responsável pelos efeitos tóxicos observados. A biotransformação por reações de Fase I e II podem contribuir para a toxicidade in vivo, por originarem o metabólito reduzido, e como o sulindaco é utilizado em terapias que envolvem uso por tempo prolongado, é prudente realizar um monitoramento da função hepática antes e durante o período de tratamento, no sentido de prevenir complicações do uso na terapia convencional / Sulindac is a nonsteroidal anti-inflammatory drug (NSAID) known to inhibit non-selectively ciclooxygenases (COX) 1 and 2. Sulindac is therapeutically used as anti-inflammatory and analgesic in the symptomatic treatment of acute and chronic rheumatoid arthritis, osteoarthritis, and ankylosing spondylits. In addition to this property, a role in the prevention/regression of colonic carcinogenesis, has been described for both sulindac and metabolites. Nevertheless, its therapeutic use has been limited because of its toxicity to the gastrointestinal tract and liver, reported in the literature. Sulindac is a prodrug that is ?in vivo? metabolized to its pharmacological active metabolite, sulindac sulfide and its pharmacological inactive one, sulindac sulfone. In order to assess the effects of sulindac and its metabolites, we used ?in vitro? studies with isolated rat liver mitochondria, to evaluate the aspects of its toxicity in mitochondria; and studies with human hepatoma cell line (HepG2), to evaluate its affects after biotransformation. The present study shows that sulindac sulfide, but not sulindac sulfone or sulindac itself, cause mitochondrial uncoupling, releasing pre-accumulated Ca2+ from the organelle, and decrease Hep-G2 cell viability in an apparent association with cellular ATP depletion resulted from mitochondrial uncoupling-associated membrane potential dissipation. We therefore propose mitochondrial uncoupling by sulindac sulfide as a potential mechanism for the well established toxicity of sulindac, at least to the liver in humans. It was also observed a mitochondrial swelling in energized media that can occur without dependence on the calcium present in the media. This event was partial inhibited by CsA and Mg2+, and completely inhibited with the addition of BHT. It did not show any inhibition with the addition of ADP, ATP, DTT or NEM. These results can not be associated to the classical mitochondrial permeability transition that is dependent to calcium, and the mechanism of inhibition observed with BHT is not known, since it was not observed any production of free radicals in our models, but the swelling observed can also contribute to the toxic effects observed. The sulindac itself and the sulfone metabolite did not show any toxic effect observed for the sulfide form, indicating that just the pharmacological active metabolite is responsible for the toxic effects. The biotransformation (phase I and II reactions) can contribute to sulindac toxicity, because they generate the reduced form. Sulindac is also used in long term treatment, so it is necessary the monitoring of the hepatic function is necessary before and during the treatment, in order to prevent any further complication.

Made available in DSpace on 2015-04-14T13:35:51Z (GMT). No. of bitstreams: 1 453321.pdf: 2208938 bytes, checksum: 36179d9e8ff3571a84f104fd9b7bd8ef (MD5) Previous issue date: 2013-12-18 / Fibrosis is a chronic liver disease that is a major cause of human mortality and is characterized by the accumulation of extracellular matrix in response to chronic liver injury. Important causes of chronic liver injury are: viral hepatitis, metabolic diseases, autoimmune diseases and exposure to chemicals, such as alcohol or drugs. The GRX cells are a representative line of hepatic stellate cells (HSC), which is associated with development of fibrosis, in the last stage is the cirrhosis. In healthy liver, these cells exhibit a phenotype or quiescent lipocyte characterized by its hability to store lipid droplets. Gallic acid is involved in several biological processes such as cell growth inhibition and apoptosis also has a variety of pharmacological actions, including antioxidant activity, anti-inflammatory, antimicrobial and antitumor. The aim of this study was to investigate the in vitro effects of gallic acid on the phenotype of HSC. The results showed that gallic acid is able to reduce cell proliferation, induce quiescent phenotype in HSCs by increasing lipid droplets, probably by activating peroxisome proliferator-activated receptor gama, decrease of transforming growth factor 1 signaling and decreased expression of collagen type I. These results demonstrate that the gallic acid may be a novel therapeutic agent for treating hepatic fibrosis. / A fibrose ? uma doen?a cr?nica do f?gado que representa uma das maiores causas de mortalidade humana e ? caracterizada pelo ac?mulo de matriz extracelular em resposta ? les?o hep?tica cr?nica. Importantes causas de les?es hep?ticas cr?nicas s?o: hepatites virais, doen?as metab?licas, doen?as autoimunes e exposi??o a subst?ncias qu?micas, como ?lcool ou drogas. As c?lulas GRX s?o uma linhagem representativa das c?lulas estreladas hep?ticas (HSC), que est? associada ao desenvolvimento da fibrose que, em ?ltimo est?gio, ? a cirrose. No f?gado saud?vel, estas c?lulas apresentam um fen?tipo quiescente ou lipoc?tico, caracterizado pela sua capacidade de armazenar got?culas lip?dicas. O ?cido g?lico est? envolvido em v?rios processos biol?gicos, tais como a inibi??o do crescimento celular e apoptose, al?m de possuir uma variedade de a??es farmacol?gicas, incluindo as atividades antioxidantes, anti-inflamat?rias, antimicrobiana e antitumoral. O objetivo deste estudo foi investigar os efeitos in vitro do ?cido g?lico sobre o fen?tipo das HSC. Os resultados obtidos mostraram que o ?cido g?lico ? capaz reduzir a prolifera??o celular, induzir o fen?tipo quiescente nas HSCs pelo aumento de got?culas lip?dicas, provavelmente pela ativa??o do receptor ativado por proliferador de peroxissomo gama, bloqueio da sinaliza??o de fator de transforma??o do crescimento beta 1 e diminui??o da express?o do col?geno tipo I. Estes resultados demonstram que o ?cido g?lico pode ser um novo agente terap?utico para o tratamento de fibrose hep?tica.

Materials based on novel Off-Stoichiometry Thiol-Ene polymers, abbreviated OSTE, show promising properties as materials forlow cost and scalable manufacturing of micro- and nanosystems such as lab-on-chip devices. The OSTE materials have tunablemechanical properties, offer possibility for low temperature bonding to many surfaces via tunable surface chemistry, and can beused in soft lithography. Unlike the commonly used elastomer poly(dimethylsiloxane), PDMS, the OSTE materials have lowpermeability for gasses, are resistant to common solvents and can be more permanently surface modified.In this master’s thesis project, the OSTE materials have been evaluated with focus on compatibility with cells, possibility fornanostructuring using soft lithography and the use of OSTE as a flexible support for conducting polymers.Results from cell seeding studies with HEP G2 cells suggest that cells can proliferate on a low thiol off-stoichiometry OSTEmaterial for at least five days. The biocompatibility for this type of OSTE material may be similar to poly(styrene). However, highlevels of free thiol monomers in the material decrease cell viability considerably.By using soft lithography techniques it is possible to fabricate OSTE nanochannels with at least the dimensions of 400 nm x 15nm. Combined with the advantages of using the OSTE materials, such as low temperature bonding and possibility for stablesurface modifications, a candidate construction material for future development of systems for DNA analysis is at hand.OSTE can serve as a flexible support for an adsorbed film of a conducting polymer with the possibility for future applicationssuch as electronic interfaces in microsystems. In this project, a film of PEDOT:PSS with the electrical resistance of ~5 kΩ wascreated by adsorption to an flexible OSTE material. Furthermore, results suggest that it is possible to further optimize theconductivity and water resistance of PEDOT:PSS films on OSTE.

No description available.

The ATLAS experiment pushes the leading edge of experimental particle physics. Increasingly complex hardware, however, brings increasingly complex problems which manifest themselves not only in the detector, but also within the software which drives the detector. The magnitude of the expected interaction rate, too, adds enormous stress to the detector system and the software trigger. In order to prepare the software for these challenges, various detector quantities are considered which may provide debugging handles and robustness against detector problems arising in the ATLAS calorimeter trigger. The effect of electronics noise suppression on these quantities is studied and a brief study of the software trigger performance is followed by recommendations for the implementation of robustness checks.

An intra-pulse Interaction Point fast feedback system (IPFB) has been designed for the Next Linear Collider (NLC), to correct relative beam-beam misalignments at the Interaction Point (IP). This system will utilise the large beam-beam kick that results from the beam-beam interaction and apply a rapid correction to the beam misalignment at the IP within a single bunch train. A detailed examination of the IPFB system is given, including a discussion of the necessary electronics, and the results of extensive simulations based on the IPFB concept for fast beam correction are presented. A recovery of the nominal luminosity of the NLC is predicted well within the NLC bunch train of 266 ns. The FONT experiment - Feedback On Nanosecond Timescales - was proposed as a direct test of the IPFB concept and was realised at the NLC Test Accelerator at SLAC. As part of FONT, a novel X-band BPM was designed and tested at the NLCTA. The results of these tests with the NLCTA short and long-pulse beam are presented, demonstrating a linear response to the position of the 180 ns long-pulse beam: measurements show a time constant of ~1.5 ns and a precision of better than 20 microns. A novel BPM processor for use at X-band, making use of the difference-over-sum processing technique, is also presented in detail, with results given for both short and long-pulse beams. The FONT design concepts and modification of the IPFB system for use at the NLCTA are described. The design of a fast charge normalisation circuit, to process the difference and sum signals produced by the BPM processor, forming part of the FONT feedback circuit, is detailed extensively. Bench tests of the feedback electronics demonstrate the effectiveness of the normalisation and feedback stages, for which a signal latency of 11 ns was measured. These bench tests also show the correct operation of the normalisation and feedback principles. Finally, the results of a full beam test of the FONT system are presented, during which a system latency of 70 ns was measured. These rigorous tests establish the soundness of the IPFB scheme and show correction of a mis-steered bunch train within the full NLCTA pulse length of 180 ns.

This thesis presents the results of a comparison between collision data and simulations based on Monte Carlo methods. The experimental dataset consists of $20.3\,\mathrm{fb}^{-1}$ of proton-proton collision data at $\sqrt s = 8\tev$ collected during 2012 by the ATLAS experiment located at the Large Hadron Collider. The final state used is $e\mu + \mathrm{jets}$. Four regions are defined, pretag ($\geq0$ jets, $\geq0$ $b$-jets), $\geq1$-tag ($\geq1$ jets, $\geq1$ $b$-jets), $\geq2$-jet ($\geq2$ jets, $\geq0$ $b$-jets), and 2-tag ($\geq2$ jets, 2 $b$-jets). Data and simulations are consistent in all regions considered.

Made available in DSpace on 2015-03-03T14:02:14Z (GMT). No. of bitstreams: 1 JussaraMCM_Tese.pdf: 1097860 bytes, checksum: 122136921e4dddbf8d0e434cbbbd3653 (MD5) Previous issue date: 2009-12-03 / The activation of hepatic stellate cells (HSC) is considered the most important event in hepatic fibrogenesis. The precise mechanism of this process is unknown in autoimmune hepatitis (AIH), and more evidence is needed on the evolution of fibrosis. The aim of this study was to assess these aspects in children with type 1 AIH. We analyzed 16 liver biopsy samples from eight patients, paired before treatment and after clinical remission, performed an immunohistochemical study with anti-actin smooth muscle antibody and graded fibrosisand inflammation on a scale of 0:4 (Batts and Ludwig scoring system). We observedthere was no significant reduction in fibrosis scores after 24? 18 months (2.5 ? 0.93 vs. 2.0? 0.53, P = 0.2012). There was an important decrease in inflammation: portal (2.6 ?0.74 vs. 1.3? 0.89, P = 0.0277), periportal/periseptal (3.0 ?0.76 vs. 1.4 ? 1.06, P = 0.0277), and lobular (2.8 ? 1.04 vs. 0.9? 0.99, P =0.0179). Anti-actin smooth muscle antibodies were expressed in the HSC of the initial biopsies (3491.93 ?2051.48 lm2), showing a significant reduction after remission (377.91 ?439.47 lm2) (P = 0.0117). HSC activation was demonstrated in the AIH of children. The reduction of this activation after clinical remission, which may precede a decrease in fibrosis, opens important perspectives in the follow-up of AIH. / A ativa??o das c?lulas hep?ticas estreladas (CHE) ? considerada o evento mais importante na fibrog?nese hep?tica. Na hepatite autoimune (HAI) este mecanismo ? desconhecido e maiores evid?ncias s?o necess?rias quanto ? evolu??o da fibrose. O objetivo desse estudo foi avaliar a ativa??o das CHE e a evolu??o da fibrose hep?tica em crian?as portadoras de HAI tipo 1. Foram analisadas 16 bi?psias hep?ticas pareadas de oito pacientes, antes do tratamento e ap?s a remiss?o cl?nica atrav?s de estudo imuno-histoqu?mico com anticorpo anti-??-actina de m?sculo liso e realizada a grada??o da fibrose e da inflama??o empregando-se o sistema de escores de Batts e Ludwig (0-4). N?o houve significante redu??o nos escores de fibrose ap?s intervalo de tempo de 24? 18 meses entre as bi?psias (2,5 ? 0,93 vs. 2,0? 0,53, P = 0,2012). Observou-se redu??o significante na inflama??o: portal (2,6?0,74 vs. 1,3? 0,89, P = 0,0277), periportal/perisseptal (3,0 ?0,76 vs. 1,4 ? 1,06, P =0,0277) e lobular (2,8 ? 1,04 vs. 0,9? 0,99, P =0,0179). A -actina de m?sculo liso nas CHE foi expressa em bi?psias hep?ticas iniciais (3491,93 ?2051,48 ?m2) e mostrou significante redu??o ap?s a remiss?o cl?nica (377,91 ?439,47 ?m2) (P = 0,0117). A ativa??o de CHE foi demonstrada em crian?as portadoras de HAI tipo 1. A redu??o de sua ativa??o ap?s remiss?o cl?nica, a qual pode preceder a redu??o da fibrose, abre importantes perspectivas no follow-up da HAI

O sulindaco é um antiinflamatório não esteroidal (AINE) classificado quimicamente como ácido carboxílico, da classe dos acetatos, que inibe de forma não seletiva a cicloxigenase 1 e 2. Terapeuticamente, é utilizado como agente analgésico e antiinflamatório para o tratamento de sintomas da artrite reumatóide aguda e crônica, osteoartrite e espondilite anquilosante, no entanto, seu uso não está restringido somente a estas patologias, pois apresenta atividade quimiopreventiva, sendo atualmente também utilizado para este fim, apesar de inúmeros relatos de toxicidade gastrointestinal e hepática terem sido relatados na literatura. Ele é ingerido como um pró-fármaco, e por reações de biotransformação hepática origina um metabólito reduzido (sulindaco sulfeto, ativo farmacologicamente) e outro oxidado (sulindaco sulfona, inativo). Para avaliar os efeitos do sulindaco e seus metabólitos, foram realizados estudos in vitro em mitocôndrias isoladas de fígado de rato, para explorar aspectos mecanísticos de toxicidade mitocondrial, e ensaios com linhagem celular de hepatoma humano HepG2, para avaliar seus efeitos após metabolização, uma vez que estas células mantém enzimas responsáveis pelas reações de biotransformação de fase I e II. Nossos resultados demonstram que o sulindaco sulfeto estimula a respiração de estado 4 e promove a liberação de cálcio pré-acumulado pela organela de maneira concentração-dependente, sendo evidente o efeito desacoplador sobre a fosforilação oxidativa, refletidos na diminuição da viabilidade celular em associação com a diminuição do conteúdo de ATP, provocado pela dissipação do potencial de membrana mitocondrial, sugerindo um mecanismo protonoforético de desacoplamento, responsável pela toxicidade deste antiinflamatório. Além disso, foi observado o inchamento das mitocôndrias em meio energizado, condição que ocorre independente de cálcio presente no meio reacional. Este evento foi parcialmente sensível a ciclosporina A e Mg2+, teve prevenção total com a adição de BHT e insensibilidade a outros moduladores, como ADP, ATP, DTT e NEM. Os resultados não condizem com a transição de permeabilidade mitocondrial clássica, uma vez que é dependente de cálcio, e o mecanismo de prevenção deste efeito obtida com a adição de BHT é desconhecido, pois não foi observada a indução de formação de radicais livres nos dois modelos experimentais utilizados. No entanto, a indução de intumescimento mitocondrial pode contribuir para seus efeitos tóxicos. O sulindaco e o sulindaco sulfona não apresentaram quaisquer efeitos descritos para o sulindaco sulfeto, indicando que somente o metabólito farmacologicamente ativo é responsável pelos efeitos tóxicos observados. A biotransformação por reações de Fase I e II podem contribuir para a toxicidade in vivo, por originarem o metabólito reduzido, e como o sulindaco é utilizado em terapias que envolvem uso por tempo prolongado, é prudente realizar um monitoramento da função hepática antes e durante o período de tratamento, no sentido de prevenir complicações do uso na terapia convencional / Sulindac is a nonsteroidal anti-inflammatory drug (NSAID) known to inhibit non-selectively ciclooxygenases (COX) 1 and 2. Sulindac is therapeutically used as anti-inflammatory and analgesic in the symptomatic treatment of acute and chronic rheumatoid arthritis, osteoarthritis, and ankylosing spondylits. In addition to this property, a role in the prevention/regression of colonic carcinogenesis, has been described for both sulindac and metabolites. Nevertheless, its therapeutic use has been limited because of its toxicity to the gastrointestinal tract and liver, reported in the literature. Sulindac is a prodrug that is ?in vivo? metabolized to its pharmacological active metabolite, sulindac sulfide and its pharmacological inactive one, sulindac sulfone. In order to assess the effects of sulindac and its metabolites, we used ?in vitro? studies with isolated rat liver mitochondria, to evaluate the aspects of its toxicity in mitochondria; and studies with human hepatoma cell line (HepG2), to evaluate its affects after biotransformation. The present study shows that sulindac sulfide, but not sulindac sulfone or sulindac itself, cause mitochondrial uncoupling, releasing pre-accumulated Ca2+ from the organelle, and decrease Hep-G2 cell viability in an apparent association with cellular ATP depletion resulted from mitochondrial uncoupling-associated membrane potential dissipation. We therefore propose mitochondrial uncoupling by sulindac sulfide as a potential mechanism for the well established toxicity of sulindac, at least to the liver in humans. It was also observed a mitochondrial swelling in energized media that can occur without dependence on the calcium present in the media. This event was partial inhibited by CsA and Mg2+, and completely inhibited with the addition of BHT. It did not show any inhibition with the addition of ADP, ATP, DTT or NEM. These results can not be associated to the classical mitochondrial permeability transition that is dependent to calcium, and the mechanism of inhibition observed with BHT is not known, since it was not observed any production of free radicals in our models, but the swelling observed can also contribute to the toxic effects observed. The sulindac itself and the sulfone metabolite did not show any toxic effect observed for the sulfide form, indicating that just the pharmacological active metabolite is responsible for the toxic effects. The biotransformation (phase I and II reactions) can contribute to sulindac toxicity, because they generate the reduced form. Sulindac is also used in long term treatment, so it is necessary the monitoring of the hepatic function is necessary before and during the treatment, in order to prevent any further complication.