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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Modelo experimental de tumor no pulmÃo com implante de cÃlulas tumorais por via intrabrÃnquica: avaliaÃÃo dos efeitos da Talidomida, Gefitinib e Paclitaxel / Experimental model of tumor in the lung with implantation of tumorais cells for saw intrabrÃnquica: evaluation of the effect of the Talidomida, Gefitinib and Paclitaxel

Antero Gomes Neto 04 October 2006 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O cÃncer de pulmÃo tem sido, na Ãltima dÃcada, a principal causa de morte por cÃncer no mundo, apesar do surgimento de novos quimioterÃpicos e das terapias alvo-direcionadas. Por isso, faz-se necessÃrio o entendimento das alteraÃÃes moleculares e biolÃgicas envolvidas nos processos de carcinogÃnese e crescimento tumoral, bem como o desenvolvimento de modelos experimentais adequados que permitam estudar o comportamento biolÃgico dos tumores de pulmÃo e o efeito de drogas antineoplÃsicas. O objetivo desse estudo foi desenvolver um modelo de tumor no pulmÃo em ratos imunocompetentes de execuÃÃo simples e fÃcil reprodutibilidade, e avaliar a atividade de drogas antitumorais. Cento e noventa e um ratos Wistar fÃmeas, peso mÃdio de 199Â23g, foram distribuÃdos ao acaso em trÃs etapas experimentais. Todos os animais foram anestesiados com tribromoetanol 2,5% (1 ml/100g de rato) intraperitonial (ip), traqueostomizados e intubados com cateter de polietileno 16G, seguindo-o por via intrabrÃnquica (ib) atà as porÃÃes inferiores do pulmÃo para inocular cÃlulas do tumor 256 de Walker. A 1a etapa (n=32) foi feita para estabelecer a tÃcnica do implante de cÃlulas por via ib e o Ãndice de pega tumoral, inoculando-se de 105 a 5Ã105 cÃlulas. A 2a etapa (n=16) para avaliar o volume tumoral no 5o dia do implante de 4Ã105 cÃlulas e correlacionar os achados da tomografia computadorizada de alta resoluÃÃo (TCAR) de tÃrax com os da necropsia. A 3a etapa (n=143) para a avaliar o efeito de drogas e validar o modelo, sendo dividida em duas fases. A 1a fase (n=72) para avaliar o volume tumoral no 5o ou 6o dia do implante de 4Ã105 cÃlulas do tumor, composta de cinco grupos: Grupo controle (Gc), NaCl 0,9% (1ml/gavagem); Grupo celecoxib (Gclx), 15, 30 e 60 mg/kg/dia/gavagem; Grupo talidomida (Gtld), 45 mg/kg/d/sc; Grupo gefitinib (Ggfb), 25 mg/kg/dia; Grupo talidominda + gefititinib (Gtld +gfb). A 2a fase (n=71) para avaliar a sobrevida dos animais, com seis grupos: Gc, Gclx (15, 30, 60), Gtld, Ggfb, Gtld + gfb, Grupo paclitaxel (Gpcl), 8 mg/kg ip. O Ãndice geral de pega do tumor com o implante 4Ã105 cÃlulas foi de 96% (149/155), sendo 90% na 1a etapa, 100% na 2a etapa e 96% na 3a etapa. A mortalidade cirÃrgica foi de 4,2% (8/191) e 21 animais foram excluÃdos do estudo por ausÃncia de tumor no pulmÃo, morte por infecÃÃo (abscesso pulmonar) e outras causas nÃo relacionadas com o tumor. Na 2a etapa, as medidas do tumor feitas na TCAR e comparadas com a necropsia foram semelhantes (r=0, 953, p<0,0001). Na 1a fase da 3a etapa, nÃo se observou diferenÃa no volume tumoral dos animais dos grupos tratados em relaÃÃo ao controle; e na 2a fase verificou-se aumento significante da sobrevida mediana dos animais tratados com TLD, GFB e PCL (13, 13 e 29 dias, respectivamente), em relaÃÃo ao controle (11dias), teste de Log Rank: p<0,001. Conclui-se que o modelo de tumor de pulmÃo por implantaÃÃo de cÃlulas tumorais por via intrabrÃnquica mostrou-se viÃvel, com alto Ãndice de pega e mortalidade cirÃrgica desprezÃvel, de execuÃÃo simples e fÃcil reprodutibilidade. A TCAR revelou-se um mÃtodo de imagem de alta acurÃcia no diagnÃstico, localizaÃÃo e mensuraÃÃo das lesÃes tumorais. O modelo mostrou-se eficaz na avaliaÃÃo de atividade antitumoral de drogas antineoplÃsicas como o paclitaxel, antiangiogÃnicas como a talidomida, e inibidores de tirosina quinase do EGFR como o gefitinib. / Lung cancer has been the main cause of death from cancer worldwide over the past decade in spite of the appearance of new chemotherapy drugs and targeted therapies. It is therefore necessary to clarify the molecular and biological changes involved in carcinogenesis and tumor growth and to develop experimental models for the study of the biology of lung tumors and the effects of antineoplastic drugs. The objective of the study was to develop a practical and easily reproducible lung tumor model using immunocompetent rats and to evaluate the activity of antineoplastic drugs. One hundred ninety-one female Wistar rats, with an average weight of 199Â23g, were randomly assigned to one of three experimental groups. All animals were anesthetized intraperitonially (ip) with 2.5% tribromoetanol (1ml/100g live weight), tracheostomized and intubated with a polyethylene catheter (16G) guided intrabronchially (ib) to the bottom of the lung for inoculation with Walker 256 tumor cells. Group 1 (n=32) established the ib cell implant technique and the tumor take rate with inoculation of 105 to 5Ã105 cells. Group 2 (n=16) evaluated tumor volume on the fifth day of implant with 4Ã105 cells and correlated chest findings from high-resolution computerized tomography (HRCT) and necropsy. Group 3 (n=143) evaluated the effect of antineoplastic drugs and validated the model in two stages. Stage 1 (n=72) evaluated tumor volume on the fifth day of implant with 4Ã105 cells, divided into 5 groups: control (CG), 0.9% NaCl (1ml/gavage); celecoxib (Gclx), 15, 30 and 60mg/kg/day/gavage; thalidomide (Gtld), 45mg/kg/d/sc; gefitinib (Ggfb), 25mg/kg/day/gavage; and thalidomide + gefitinib (Gtld + gfb). Stage 2 (n=71) evaluted the survival of the animals divided into six groups: Gc, Gclx, Gtld, Ggfb, Gtld + gfb, and Gpcl (paclitaxel) 8mg/kg ip. The overal take rate for implants of 4Ã105 cells was 96% (149/155), specifically 90% in the first experimental group, 100% in the second and 96% in the third. Surgical mortality was 4.2% (8/191); 21 animals were excluded due to absence of tumor in the lung, death from infection (pulmonary abscess) and other causes not related to the tumor. In Group 2, measures obtained with HRCT and necropsy were similar (r=0, 953, p<0.0001). In the first stage of Group 3 no difference in tumor volume was observed between treated animals and controls; in the second stage median survival time was significantly extended in animals treated with TLD, GFB and PCL (13, 13 and 29 days, respectively) compared to controls (11 days) (Log Rank test: p<0.001). In conclusion, the present lung tumor model with intrabronchial tumor cell implantation was shown to be feasible and was associated with high tumor take rates, minor surgical mortality, simple execution and easy reproducibility. HRCT was found to be a highly accurate method of diagnosis, localization and tumor measurement. The model was efficient in the evaluation of the antitumoral activity of the antineoplastic drug paclitaxel, the antiangiogenic drug thalidomide, and the EGFR tyrosine kinase inhibitor gefitinib, making it a valid model for testing new drugs in lung cancer.
52

Avaliação de novos análogos da talidomida quanto à inibição da produção de óxido nítrico, citocinas pró-inflamatórias e expressão de CD80 e CD 86 em macrófagos

Mazzoccoli, Luciano 29 April 2009 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-04-26T14:09:15Z No. of bitstreams: 1 lucianomazzoccoli.pdf: 1325202 bytes, checksum: 7054f92647dc1e9d86442d0be8eec899 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-12T15:47:04Z (GMT) No. of bitstreams: 1 lucianomazzoccoli.pdf: 1325202 bytes, checksum: 7054f92647dc1e9d86442d0be8eec899 (MD5) / Made available in DSpace on 2017-05-12T15:47:04Z (GMT). No. of bitstreams: 1 lucianomazzoccoli.pdf: 1325202 bytes, checksum: 7054f92647dc1e9d86442d0be8eec899 (MD5) Previous issue date: 2009-04-29 / A talidomida é utilizada no tratamento de diversas doenças incluindo o eritema nodoso leproso (ENL), uma complicação inflamatória da Hanseníase. Contudo, apresenta atividade teratogênica severa e novos análogos podem ser usados no tratamento da doença sem apresentar este efeito colateral. Uma série de compostos diamínicos contendo duas subunidades ftalimídicas abertas foram escolhidos como análogos da talidomida. Nossos resultados mostram que compostos contendo dois grupos ftalimídicos podem ser facilmente obtidos em elevada quantidade através da condensação de anidrido ftálico ou anidrido 3-nitroftálico com diferentes diaminas comercialmente disponíveis. O efeito destes compostos na produção de TNF-α, IL-12, IL-10 e NO, e na expressão de CD80 e CD86 em células J774A.1 estimuladas com LPS/IFN-γ foi investigado. O nível de mRNA para TNF-α, IL-12, IL-10 e iNOS em J774A.1 foi analisado por RT-PCR em tempo real. Células do sangue periférico humano (PBMC) foram usadas para avaliar a produção de TNF-α, IL-6, IFN-γ , CXCL9 e CXCL10. A produção de citocinas foi avaliada por ELISA, a produção de NO pelo método de Griess, e a expressão de CD80, CD86, CXCL9 e CXCL10 por citometria de fluxo. As células J774A.1 foram incubadas com diferentes concentrações dos compostos (entre 1 a 880 μM) e após 1h foram estimuladas com LPS (1 μg/ml) e IFN-γ (0,4 ng/ml) por 18h. PBMC humano foi incubado de forma similar e estimulado com LPS (2 μg/ml). Três compostos inibiram de forma elevada a produção de TNF-α , IL-12 e NO, conquanto que aumentaram a produção de IL-10. Além disto, inibiram a expressão de CD80, mas não de CD86. Os resultados analisados por RT-PCR em tempo real indicaram que esses compostos atuaram em eventos pós-transcricionais. Os compostos N, N'-Di-(2-carboxi-benzoil)-1,3-propanodiamina, N, N'-Di-(2-carboxi-3-nitro-benzoil)-1,2-etilenodiamina e N, N'-Di-(2-carboxi-3-nitro-benzoil)-1,6-hexanodiamina inibiram mais a produção de TNF-α do que a talidomida (IC50 de 55 μM, 5 μM, 6,1 μM e 220 μM, respectivamente) e também tiveram efeito inibitório na produção de IFN-γ, IL-6, CXCL9 e CXCL10. Os compostos não tiveram efeito na viabilidade celular avaliada por azul de Trypan e por MTT. Este trabalho mostra a síntese e caracterização de novos análogos da talidomida, obtidos em bom rendimento utilizando metodologia simples. Nossos resultados sugerem que a potencial atividade anti-inflamatória e imunorregulatória destes compostos diamínicos apresentam potencial aplicação no tratamento de ENL e outras doenças. / Thalidomide is used to treat various diseases including erythema nodosum leprosum (ENL), an inflammatory complication of leprosy. However, it has severe teratogenic activity and novel thalidomide analogues might be used to treat the disease without this severe side effect. A series of diamine compounds containing two hydrolyzed phthalimido structures were chosen as analogues of thalidomide. Our results show that compounds bearing two phthalimido units could easily be obtained in high yield by condensation of phthalic or 3-nitrophthalic anhydride with the different diamines comercially available. The effects of these compounds on production of TNF-γ, IL-12, IL-10 and NO, and on expression of CD80 and CD86 in LPS/IFN-γ stimulated J774A.1 cells were investigated. The level of TNF-, IL-12, IL-10 and iNOS mRNA in J774A.1 was analyzed by real time RT-PCR. Human peripheral blood (PBMC) was used to evaluate TNF-γ, IFN-α, CXCL9 and CXCL10 production. Cytokine production was evaluated by ELISA, NO production by the Griess assay, and CD80, CD86, CXCL9 and CXCL10 expression by cytometry. J774A.1 cells were incubated with different concentrations of the compounds (between 1 and 880 μM) and after 1h stimulated with LPS (1 μg/ml) and IFN-γ (0,4 ng/ml) for 18h. Human PBMC were similarly incubated with the compounds and stimulated by LPS (2 μg/ml). Three compounds greatly inhibited TNF-α, IL-12 and NO production while enhancing IL-10. In addition, CD80 expression was inhibited, but not CD86. The result analyzed by real time RT-PCR indicates that these compounds act in the blocking of post-transcriptional events. The compounds N, N'-Di-(2-carboxy-benzoyl)-1,3-propanediamine, N, N'-Di-(2-carboxy-3-nitro-benzoyl)-1,2-ethylenediamine e N, N'-Di-(2-carboxy-3-nitro-benzoyl)-1,6-hexanediamine inhibited TNF-α production by PBMC greater then thalidomide (IC50 de 55 μM, 5 μM, 6.1 μM and 220 μM, respectively) and also had a inhibitory effect on IFN-γ , IL-6, CXCL9 and CXCL10 production. The compounds had no effect on cell viability, evaluated by Trypan blue exclusion and MTT assay. This work describes the synthesis and characterization novel thalidomide analogues, prepared in good yields using simple methodology. Our results suggest that the potential anti-inflammatory and immunomodulatory activity of these diamine compounds is potentially applicable in treating ENL and other diseases.
53

Molecular Mechanisms and Determinants of Species Sensitivity in Thalidomide Teratogenesis

Lee, Crystal J. J. 14 August 2013 (has links)
The expanding therapeutic use of thalidomide (TD) remains limited by its species-specific teratogenicity in humans and rabbits, but not rodents. The R and S isomers of TD may be selectively responsible for its respective therapeutic and teratogenic effects, but rapid in vivo racemization makes this impossible to confirm. Fluorothalidomide (FTD), a fluorinated TD analogue with stable, non-racemizing isomers, may serve as a model compound for determining stereoselective effects. In vivo, FTD was undetectable in plasma, suggesting rapid breakdown, as confirmed in vitro, where FTD hydrolyzed up to 22-fold faster than TD. Unlike TD, FTD in pregnant rabbits and mice was highly toxic and lethal to both dams and fetuses. In rabbit embryo culture, FTD initiated optic (eye) vesicle and hindbrain but not classic limb bud embryopathies. Chemical instability, potent general toxicity and absence of limb bud embryopathies make FTD an unsuitable stereoselective model for TD teratogenesis. TD teratogenesis may involve its bioactivation by embryonic prostaglandin H synthases (PHSs) to a free radical intermediate that increases embryopathic reactive oxygen species (ROS) formation. However, the teratogenic potential of rapidly formed TD hydrolysis products and the determinants of species-specific teratogenesis are unclear. For some teratogens, mouse strains that are resistant in vivo are susceptible in embryo culture, suggesting maternal and/or placental determinants of risk. However, TD and two hydrolysis products, 2-phthalimidoglutaramic acid (PGMA) and 2-phthalimidoglutaraic acid (PGA), were non-embryopathic in CD-1 mouse embryo culture. Also, mice deficient in oxoguanine glycosylase 1 (OGG1), which repairs oxidatively damaged DNA, were resistant to TD embryopathies in culture and in vivo. Therefore, murine resistance to TD teratogenesis is dependent on embryonic factors, rather than maternal/placental determinants or increased DNA repair. In contrast, rabbit embryos exposed in culture to TD, PGMA and PGA exhibited head/brain, otic (ear) vesicle and classic limb bud embryopathies, validating the first mammalian embryo culture model for TD teratogenesis and providing the first evidence of a teratogenic role for TD hydrolysis products. Pretreatment with eicosatetraynoic acid (ETYA), a dual PHS/lipoxygenase inhibitor, or phenylbutylnitrone (PBN), a free radical spin trapping agent, completely blocked TD, PGMA and PGA-initiated embryopathies, implicating a PHS-dependent, ROS-mediated embryopathic mechanism.
54

Molecular Mechanisms and Determinants of Species Sensitivity in Thalidomide Teratogenesis

Lee, Crystal J. J. 14 August 2013 (has links)
The expanding therapeutic use of thalidomide (TD) remains limited by its species-specific teratogenicity in humans and rabbits, but not rodents. The R and S isomers of TD may be selectively responsible for its respective therapeutic and teratogenic effects, but rapid in vivo racemization makes this impossible to confirm. Fluorothalidomide (FTD), a fluorinated TD analogue with stable, non-racemizing isomers, may serve as a model compound for determining stereoselective effects. In vivo, FTD was undetectable in plasma, suggesting rapid breakdown, as confirmed in vitro, where FTD hydrolyzed up to 22-fold faster than TD. Unlike TD, FTD in pregnant rabbits and mice was highly toxic and lethal to both dams and fetuses. In rabbit embryo culture, FTD initiated optic (eye) vesicle and hindbrain but not classic limb bud embryopathies. Chemical instability, potent general toxicity and absence of limb bud embryopathies make FTD an unsuitable stereoselective model for TD teratogenesis. TD teratogenesis may involve its bioactivation by embryonic prostaglandin H synthases (PHSs) to a free radical intermediate that increases embryopathic reactive oxygen species (ROS) formation. However, the teratogenic potential of rapidly formed TD hydrolysis products and the determinants of species-specific teratogenesis are unclear. For some teratogens, mouse strains that are resistant in vivo are susceptible in embryo culture, suggesting maternal and/or placental determinants of risk. However, TD and two hydrolysis products, 2-phthalimidoglutaramic acid (PGMA) and 2-phthalimidoglutaraic acid (PGA), were non-embryopathic in CD-1 mouse embryo culture. Also, mice deficient in oxoguanine glycosylase 1 (OGG1), which repairs oxidatively damaged DNA, were resistant to TD embryopathies in culture and in vivo. Therefore, murine resistance to TD teratogenesis is dependent on embryonic factors, rather than maternal/placental determinants or increased DNA repair. In contrast, rabbit embryos exposed in culture to TD, PGMA and PGA exhibited head/brain, otic (ear) vesicle and classic limb bud embryopathies, validating the first mammalian embryo culture model for TD teratogenesis and providing the first evidence of a teratogenic role for TD hydrolysis products. Pretreatment with eicosatetraynoic acid (ETYA), a dual PHS/lipoxygenase inhibitor, or phenylbutylnitrone (PBN), a free radical spin trapping agent, completely blocked TD, PGMA and PGA-initiated embryopathies, implicating a PHS-dependent, ROS-mediated embryopathic mechanism.
55

[en] DEVELOPMENT AND COMPARATIVE STUDY OF SPECTROFLUORIMETRIC AND VOLTAMMETRIC METHODOLOGIES FOR THE DETERMINATION OF THALIDOMIDE IN ONE COMMERCIAL FORMULATION, URINE AND BLOOD SERUM / [pt] DESENVOLVIMENTO E ESTUDO COMPARATIVO DE METODOLOGIAS ESPECTROFLUORIMÉTRICA E VOLTAMÉTRICA PARA A DETERMINAÇÃO DE TALIDOMIDA EM UM FÁRMACO, URINA E SORO SANGÜÍNEO

CARLOS EDUARDO CARDOSO 21 July 2003 (has links)
[pt] No presente trabalho foram desenvolvidas duas metodologias analíticas para a determinação de talidomida, um composto de reconhecida importância farmacológica. As metodologias espectrofluorimétrica e voltamétrica desenvolvidas foram comparadas em termos de desempenho analítico.As características fluorescentes e eletroquímicas da talidomida foram estudadas para que se encontrassem condições experimentais que fornecessem máximo sinal fluorescente do analito em solução na temperatura ambiente e possibilidade de pré-concentração do analito no eletrodo de mercúrio.Nas condições experimentais otimizadas para a talidomida, limites de detecção compreendidos entre 10-6 e 10-9 g L-1 foram obtidos para o método espectrofluorimétrico e voltamétrico, respectivamente. Faixas lineares dinâmicas entre 2 e 4 ordens de grandeza foram alcançadas dependendo do método e do interferente presente na amostra. Esses parâmetros de mérito se mostraram adequados para o problema proposto. O possível efeito interferente de substâncias geralmente usadas em associação com o analito foi estudado, e estratégias para minimização das interferências foram desenvolvidas. Enquanto a tetraciclina não interferiu no método espectrofluorimétrico, o uso combinado de meio ácido e irradiação UV da amostra foi necessária para permitir a quantificação do analito em presença de sulfanilamida. Na voltametria, as interferências da tetraciclina e da sulfanilamida puderam ser compensadas pelo uso da quantificação pelo método de adição do analito. Nas determinações dos fluídos biológicos, o uso da extração em coluna de sílica C18 mostrou-se bastante eficiente na separação do analito dos interferentes da matriz para o método espectrofluorimétrico e para o voltamétrico, no caso do soro sangüíneo. Para a urina, apenas a clarificação da amostra com sulfato de amônio foi suficiente no caso da determinação voltamétrica.Os métodos desenvolvidos foram testados na dosagem de talidomida presente em uma formulação comercial e em amostras de urina e soro sangüíneo enriquecidas com o analito. Para tal, utilizaram-se os procedimentos de curva de calibração (espectrofluorimetria) e método da adição do analito (voltametria). Em todos os casos, as recuperações obtidas estiveram compreendidas na faixa de 96,5 a 107,6 %, dentro da faixa de recuperação estabelecida pela Farmacopéia dos Estados Unidos da América. / [en] In the present work two analytical methodologies were developed aiming the determination of thalidomide, an important pharmacological compound. The developed spectrofluorimetric and the voltammetric based analytical methodologies were compared in terms of analytical performance. The thalidomide fluorescent and the electrochemical characteristics were studied in order to find experimental conditions for maximum fluorescence in solution and at room temperature and to allow analyte pre- concentration on the mercury electrode. Using the optimized experimental conditions, limits of detection between 10-6 to 10-9 g L-1 were achieved respectively for the spectrofluorimetric method and for the voltammetric method. Dynamic linear ranges between 2 and 4 orders of magnitude were obtained depending on the method utilized and the interferent substances present in the sample. Those parameters of merit were suitable for this proposed analytical problem. The potential interference effect from substances usually used in association with thalidomide, were studied and strategies for the minimization of such interferences were developed. While no interference in the spectrofluorimetric method was observed for tetracycline, the combined use of acidic medium and UV irradiation of the samples was necessary to allow the analyte determination in the presence of sulfanilamide. For the voltammetric method, interferences from tetracycline and sulfanilamide could be compensated by quantifying thalidomide using the analyte addition method. For the determination in biological fluids, the use a solid-liquid extraction on a C18 column was found to be very effective for the analyte separation and elimination of matrix interferences for the spectrofluorimetric method and for the voltammetric method developed for blood serum. For urine samples, a clean-up step using ammonium sulfate was found to be sufficient for the voltammetric determination of thalidomide. The developed methodologies were tested by determining the thalidomide content in a commercial pharmaceutical formulation and in analyte spiked biological fluids using calibration curves (spectrofluorimetric) and analyte addition method (voltammetric). In all cases, the recoveries were between the 96,5 and 107,6 %, within the recovery range considered adequate according to the United States Pharmacopoeia.

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