Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-02-21T21:07:29Z No. of bitstreams: 1 MariliaDanielaFerreiraDeCarvalhoMoreira_TESE.pdf: 929428 bytes, checksum: 122ddbe6f0f95a006b02637a7a41c56e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-02-22T20:36:24Z (GMT) No. of bitstreams: 1 MariliaDanielaFerreiraDeCarvalhoMoreira_TESE.pdf: 929428 bytes, checksum: 122ddbe6f0f95a006b02637a7a41c56e (MD5) / Made available in DSpace on 2018-02-22T20:36:24Z (GMT). No. of bitstreams: 1 MariliaDanielaFerreiraDeCarvalhoMoreira_TESE.pdf: 929428 bytes, checksum: 122ddbe6f0f95a006b02637a7a41c56e (MD5) Previous issue date: 2017-12-12 / Estudos sobre a influ?ncia do c?lon na regenera??o hep?tica s?o escassos. Alguns t?m demonstrado que ap?s a colectomia ocorre aumento da regenera??o e sua redu??o em outros. Diante da controv?rsia, este trabalho visou examinar se a colectomia associada ? hepatectomia 70% influencia par?metros de regenera??o do f?gado em ratos. Foram utilizados 18 ratos Wistar distribu?dos em 3 grupos (6 animais cada). No grupo I (sham) foi realizada uma laparotomia com leve manipula??o de al?as; no grupo II uma colectomia + hepatectomia 70%; e no grupo III apenas hepatectomia 70%. No 6? dia p?s-operat?rio foi colhido sangue por pun??o card?aca sob anestesia, seguido de eutan?sia. Realizadas dosagens s?ricas de alanina aminotransferase (ALT), aspartato amino transferase (AST), fosfatase alcalina (FA), albumina, fator de crescimento de hepat?citos (HGF) e fator de crescimento transformador-? (TGF-?). A regenera??o do f?gado foi calculada pela f?rmula: (raz?o do peso do f?gado por 100g do peso corporal no momento da eutan?sia/peso do f?gado no pr?-operat?rio projetado por 100g de peso corporal) ? 100. Os testes de an?lise de vari?ncia (ANOVA) e Tukey foram usados, com signific?ncia p<0,05. Resultados: Houve uma menor e significante magnitude dos n?veis de ALT e AST no grupo II comparados com o grupo III (p<0,001). A albuminemia mostrou n?veis significativamente mais elevados no grupo II que no III. Os n?veis de HGF (408?18,2 pg/mL) e TGF-? (3,8?0,3 ng/mL) no grupo II foram significativamente mais elevados que o HGF (360?58,6 pg/mL) e TGF-? (2,3?0,4 ng/mL) no grupo III, respectivamente (p<0,001). O percentual de regenera??o hep?tica foi significativamente mais elevado no grupo II, do que no grupo III (p=0,003). Em conclus?o, este estudo concluiu que a colectomia realizada simultaneamente ? hepatectomia 70% influenciou positivamente na regenera??o do f?gado em ratos. Pesquisas adicionais s?o necess?rias para revelar os mecanismos moleculares deste efeito e para caracterizar a influ?ncia do c?lon na fisiologia do f?gado. / Studies on the influence of the colon on liver regeneration are scarce. Some have shown that after colectomy there is an increase in regeneration and its reduction in others. Faced with the controversy, this work aimed to investigate whether colectomy simultaneously performed with 70% hepatectomy influences liver regeneration in rats. Eighteen Wistar rats were distributed in 3 groups, 6 animals each. In group I (sham) only laparotomy was performed with mild manipulation of boweld loops; in group II 70% hepatectomy and simultaneous colectomy; in group III only 70% hepatectomy. On the 6th postoperative day, blood was collected by cardiac puncture under anesthesia, and remaining liver was removed. Serum measures of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (FA), albumin, hepatocyte growth factor (HGF) and transforming growth factor-? (TGF-?) were performed. Liver regeneration was calculated by (liver weight per 100g of the body weight at sacrifice/preoperative projected liver weight per 100g of the body weight) ? 100. The Analyses of variance (ANOVA) and Tukey tests were used, with significance p<0.05. There was significant lower levels of ALT and AST in group II rats when compared to group III (p<0.001). Albuminemia showed significantly higher levels in group II rats than in III (p<0.01). Serum levels of HGF (408?18.2pg/mL) and TGF-? (3.8?0.3ng/mL) were significantly higher in group II rats than HGF (360?58.6pg/mL), TGF-? (2.3?0.4ng/mL) in group III, respectively. The percentage of liver regeneration was significantly higher in group II than in group III (p = 0.003). In conclusion, this study demonstrated that colectomy, performed simultaneously with 70% hepatectomy, positively influenced liver regeneration in rats. Further research is needed to reveal the molecular mechanisms of this effect and to characterize the effects of the colon on liver physiology.

Made available in DSpace on 2014-12-17T14:13:28Z (GMT). No. of bitstreams: 1 ToshiyukiNJ.pdf: 11006628 bytes, checksum: da763274130c0b79f55fd708108d98c7 (MD5) Previous issue date: 2009-02-05 / Micro and nanoparticulate systems as drug delivery carriers have achieved successful therapeutic use by enhancing efficacy and reducing toxicity of potent drugs. The improvement of pharmaceutical grade polymers has allowed the development of such therapeutic systems. Microencapsulation is a process in which very thin coatings of inert natural or synthetic polymeric materials are deposited around microsized particles of solids or around droplets. Products thus formed are known as microparticles. Xylan is a natural polymer abundantly found in nature. It is the most common hemicellulose, representing more than 60% of the polysaccharides existing in the cell walls of corn cobs, and is normally degraded by the bacterial enzymes present in the colon of the human body. Therefore, this polymer is an eligible material to produce colon-specific drug carriers. The aim of this study was to evaluate the technological potential of xylan for the development of colon delivery systems for the treatment of inflammatory bowel diseases. First, coacervation was evaluated as a feasible method to produce xylan microcapsules. Afterwards, interfacial cross-linking polymerization was studied as a method to produce microcapsules with hydrophilic core. Additionally, magnetic xylan-coated microcapsules were prepared in order to investigate the ability of producing gastroresistant systems. Besides, the influence of the external phase composition on the production and mean diameter of microcapsules produced by interfacial cross-linking polymerization was investigated. Also, technological properties of xylan were determined in order to predict its possible application in other pharmaceutical dosage forms / Os sistemas micro e nanoparticulados t?m sido cada vez mais utilizados por promoverem um aumento da efic?cia de um determinado medicamento bem como redu??o da toxicidade de f?rmacos potentes. A descoberta e pesquisa de materiais polim?ricos, naturais e sint?ticos, permitiram o desenvolvimento de in?meros sistemas terap?uticos. A microencapsula??o ? um processo com o qual finas camadas de um revestimento constitu?das de uma mat?ria prima polim?rica inerte, de origem natural ou sint?tica, s?o depositadas ao redor de part?culas s?lidas micronizadas ou got?culas. A xilana ? um pol?mero natural abundantemente encontrado na natureza, representando mais de 60% dos polissacar?deos presentes na parede celular dos vegetais de grande porte, entre eles o sabugo de milho. Ela ? normalmente digerida em n?vel de c?lon durante a degrada??o residual de carboidratos, realizada por um conjunto de enzimas bacterianas existentes no trato gastro intestinal. Desta maneira, este pol?mero tornou-se uma mat?ria prima eleg?vel para o desenvolvimento de carreadores c?lon espec?ficos. O objetivo deste estudo foi avaliar o potencial tecnol?gico da xilana para o desenvolvimento de uma formula??o visando a libera??o de f?rmacos no c?lon para o tratamento de dist?rbios inflamat?rios intestinais. Inicialmente, foi avaliado a capacidade de xilana formar micropart?culas pela t?cnica da coacerva??o. Posteriormente, foi estudada uma nova t?cnica de obten??o de microc?psulas com n?cleo hidrof?lico pela t?cnica da reticula??o polim?rica interfacial. Depois, sua habilidade de formar sistemas gastrorresistentes foi avaliada com as micropart?culas magn?ticas, em seguida, foi avaliada a influ?ncia da composi??o da fase externa na produ??o e di?metro m?dio das microc?psulas de xilana produzidas por reticula??o interfacial, bem como as propriedades tecnol?gicas da xilana, visando a sua aplica??o em outras formas farmac?uticas

Made available in DSpace on 2014-12-17T14:13:33Z (GMT). No. of bitstreams: 1 ElquioEO_TESE.pdf: 1649953 bytes, checksum: 1098cd34b1d3e6c9a180949d25fa8185 (MD5) Previous issue date: 2010-06-07 / Universidade Federal do Rio Grande do Norte / The aim of this work was to perform the extraction and characterization of xylan from corn cobs and prepare xylan-based microcapsules. For that purpose, an alkaline extraction of xylan was carried out followed by the polymer characterization regarding its technological properties, such as angle of repose, Hausner factor, density, compressibility and compactability. Also, a low-cost and rapid analytical procedure to identify xylan by means of infrared spectroscopy was studied. Xylan was characterized as a yellowish fine powder with low density and poor flow properties. After the extraction and characterization of the polymer, xylan-based microcapsules were prepared by means of interfacial crosslinking polymerization and their characterization was performed in order to obtain gastroresistant multiparticulate systems. This work involved the most suitable parameters of the preparation of microcapsules as well as the study of the process, scale-up methodology and biological analysis. Magnetic nanoparticles were used as a model system to be encapsulated by the xylan microcapsules. According to the results, xylan-based microcapsules were shown to be resistant to several conditions found along the gastrointestinal tract and they were able to avoid the early degradation of the magnetic nanoparticles / O presente trabalho teve como objetivo a extra??o e caracteriza??o do pol?mero de xilana a partir de res?duos de sabugo de milho e a produ??o de microc?psulas a partir deste pol?mero. O primeiro passo foi a extra??o da xilana em meio alcalino e caracteriza??o deste pol?mero quanto as suas propriedades tecnol?gicas (?ngulo de repouso, fator de Hausner, densidade, compressibilidade e compactabilidade), bem como a elabora??o de uma procedimento r?pido e barato para a identifica??o deste pol?mero atrav?s de espectroscopia de absor??o na regi?o do infravermelho. O pol?mero de xilana foi caracterizado como sendo um p? de cor amarelada de baixa densidade e com propriedades de escoamento pouco favor?veis. Ap?s a obten??o e caracteriza??o do pol?mero, microc?psulas de xilana foram preparadas atrav?s da reticula??o polim?rica interfacial e caracterizadas a fim de se obter sistemas multiparticulados gastroresistentes. O trabalho foi delineado buscando-se os melhores fatores na t?cnica de prepara??o das microc?psulas, assim como o estudo do processo, aumento de escala e avalia??o biol?gica. Nanopart?culas magn?ticas foram utilizadas como sistema modelo a ser encapsulado pelas microc?psulas ? base de xilana. Os resultados obtidos demonstraram que as microc?psulas de xilana s?o resistentes ?s diversas condi??es encontradas ao longo do trato gastrintestinal e foram capazes de evitar a degrada??o pr?via das nanopart?culas magn?ticas in vitro