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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.
31

Avaliação das propriedades físico-químicas da matéria-prima talidomida com ênfase no polimorfismo e sua influência frente à dissolução e compactação / Physicochemical properties evaluation of the thalidomide raw material and polymorphic relationship with dissolution and compaction

Carini, Juliana Poglia January 2007 (has links)
O objetivo deste trabalho foi avaliar as propriedades físico-químicas de diferentes matérias-primas de talidomida visando à identificação de parâmetros críticos a serem observados para garantir a aquisição de insumo com qualidade farmacêutica. Sete amostras foram caracterizadas a partir de estudos tecnológicos, espectroscópicos, morfológicos, térmicos e cristalográficos, sendo avaliadas frente a processos de dissolução e compactação. Os resultados obtidos demonstraram a inexistência de homogeneidade entre as matérias-primas analisadas, apresentando diferenças em relação à constituição cristalina e morfológica, comportamento térmico, velocidade de dissolução intrínseca e comportamento frente à compactação. Foi observada e quantificada a presença de fases polimórficas a e b e materiais semicristalinos. A amostra T5 demonstrou desfavoráveis propriedades tecnológicas, gerando indicativos de problemas relativos à processabilidade do fármaco em medicamento, ao contrário de T1. A análise térmica forneceu indícios de transição sólido-sólido entre fases polimórficas de fármaco, provavelmente relacionada a propriedades químico-mecânicas das amostras associadas à inserção de calor. Amostras semicristalinas apresentaram maior velocidade de dissolução intrínseca, principalmente associada ao polimorfo b, representando, possivelmente, um desvio de qualidade em processos sintéticos. Estudos preliminares indicaram que a amostra T1 exibiu melhor compactabilidade que T5. Devido a sua pureza cristalográfica e propriedades tecnológicas, a amostra T1 se mostrou a mais indicada ao desenvolvimento de comprimidos de talidomida. / The objective of this work was to evaluate physicochemical properties of different thalidomide raw material in order to identify critical parameters to assure the acquisition of a product with pharmaceutical quality. Seven samples were characterized by technological, spectroscopic, morphological, thermal and crystallographic approaches. Dissolution tests and degree of compaction were used to evaluate the samples. The results demonstrated raw materials with lack of homogeneity and differences related to crystal and morphological constitution, thermal behavior, intrinsic dissolution rate and compaction behavior. Polymorphic forms a and b and semicrystalline materials were observed and quantified. In contrast to T1, the sample T5 presented unfavorable technological properties generating indicatives of relative problems impairing the tablets manufacturing process. Thermal analysis indicated solid-solid transition between polymorphic phases probably related to chemical-mechanical properties of the samples associated with heating. Semicrystalline materials presented higher intrinsic dissolution rate than other samples, mainly related to the polymorph b, possibly representing quality deviation associated with synthetic process. Early studies indicated better compactability of sample T1 than T5. Due its crystallographic purity and technological properties, it is suggested that T1 is the sample choice to be used during the development of a pharmaceutical solid oral dosage form containing thalidomide.
32

Efeito da talidomida na vasculopatia crônica do transplante no modelo experimental de transplante da aorta / Effects of thalidomide in chronic transplant vasculopathy in an experimental model of aortic transplantation

Alexandre Chagas de Santana 25 February 2014 (has links)
A vasculopatia crônica do transplante constitui um dos principais obstáculos para o sucesso do transplante de órgãos a longo prazo. Caracteriza-se pela formação de uma camada neoíntima, que culmina no estreitamento da luz do vaso com consequente isquemia e falência do órgão transplantado. Embora diversos mecanismos imunológicos tenham sido descritos, a patogênese da vasculopatia crônica do transplante ainda não foi esclarecida e continua sem tratamento específico. Neste contexto, estratégias com alvos imunomodulatórios são de extrema importância. Dentre estas possíveis estratégias destaca-se a talidomida, uma droga que apresentada potentes propriedades anti-inflamatórias e imunomodulatórias e que recentemente voltou a ter indicações clínicas. Assim, os objetivos do presente estudo foram: 1) Padronizar o modelo experimental de vasculopatia crônica do transplante no modelo experimental de transplante de aorta, pois este modelo mimetiza as principais características observadas na parede do vaso durante o processo de rejeição; 2) Analisar o efeito da talidomida sobre as alterações morfológicas vasculares (histologia para Verhoeff), componentes celulares (expressão de a-actina, atividade proliferativa, número de macrófagos e linfócitos T, através de imuno-histoquímica), além da participação da apoptose (técnica de TUNEL); 3) Avaliar o potencial efeito anti-inflamatório e imunomodulador da talidomida neste modelo, através da análise da expressão de mediadores da resposta imune (TNF-a, IL-1b, IL-6, IL-2, INF-g, IL-4 e IL-10), bem como a atividade do NFkB e o envolvimento das subunidades p50 e p65 no enxerto vascular. Foram utilizados ratos machos das linhagens isogênicas específicas, Fisher 344 e Lewis, distribuídos em 3 diferentes grupos (32 por grupo): ISO (transplante isogênico de aorta, Fisher para Fisher); ALO (transplante alogênico de aorta, Fisher para Lewis); ALO+TALID (transplante alogênico de aorta tratado com talidomida (200mg/Kg/dia/gavagem)). Os animais foram acompanhados por um período de 30 dias e, em seguida, sacrificados. Os resultados obtidos demonstraram que a padronização do modelo experimental de transplante de aorta foi viabilizada dentro de uma sequência metodológica extremamente precisa e reprodutível. Como esperado, os animais do grupo ISO não apresentaram sinais de rejeição no enxerto vascular, mantendo íntegra a arquitetura das camadas do vaso. Por outro lado, animais do grupo ALO desenvolveram vasculopatia crônica do transplante caracterizada pelo espessamento das camadas íntima e adventícia. Na camada média evidenciou-se diminuição das VSMC e acentuado rompimento das fibras elásticas. Além disso, os animais do grupo ALO apresentaram aumento da expressão de a-actina acompanhada de intensa atividade proliferativa celular, particularmente nas camadas neoíntima e adventícia, provavelmente pela migração das VSMC para a camada íntima. A análise por IH revelou intenso infiltrado de macrófagos, linfócitos T, além de apoptose presente em todas as camadas do aloenxerto. A expressão gênica e a concentração tecidual dos mediadores da resposta imune TNF-a, IL-1b, IL-6, IL-2, INF-g e IL-10 também foram significativamente aumentadas no grupo ALO. Esses achados associaram-se com a ativação do NFkB, bem como o envolvimento dos dímeros p50 e p65. O tratamento com talidomida promoveu um efeito vasculoprotetor através da redução da camada neoíntima e da inflamação local. Além disso, induziu diminuição da expressão gênica e da concentração tecidual dos mediadores TNF-a, IL-1b, IL-6, IL-2, INF-g, bem como aumento da IL-4 e IL-10. A talidomida também diminuiu a ativação do NFkB. Conclusão: os resultados do presente estudo indicam que o modelo experimental de vasculopatia crônica do transplante constitui um modelo adequado para estudar as alterações nas camadas do vaso durante o processo de rejeição ao aloenxerto. A talidomida exerceu um efeito vasculoprotetor, atenuando a formação da neoíntima e do processo inflamatório local, bem como dos mediadores da resposta imune, provavelmente devido as suas propriedades anti-inflamatórias e imunomodulatórias / Chronic transplant vasculopathy is a major obstacle for the long-term success of organ transplantation. It is characterized by the formation of neointimal layer that culminate in the narrowing of the vessel lumen with consequent ischemia and failure of the transplanted organ. Although several immunological mechanisms have been described, the pathogenesis of chronic transplant vasculopathy remains unclear and continues without specific treatment. In this context, immunomodulatory strategies are extremely important. Among these possible strategies stands out thalidomide, a drug that display a potent antiinflammatory and immunomodulatory properties and recently have returned to clinical indications. The aims of this study were: 1) To standardize the experimental model of chronic transplant vasculopathy, induced in an experimental model of aortic transplantation, because this model mimics the key features observed in the vessel wall during the rejection process; 2) To analyze the effects of thalidomide on vascular morphological (Verhoeff staining), cellular components (a-actin expression, proliferative activity, number of macrophages and T lymphocytes by immunohistochemistry), and the participation of apoptosis (TUNEL assay); 3) To evaluate the antiinflammatory and immunomodulatory potential effects of thalidomide in this model by analyzing the mediator expression of the immune response (TNF-a, IL-1b, IL-6, IL-2, INF-g, IL-4 e IL-10), as well as the NFkB activity and involvement of p50 and p65 subunits in the vascular graft. We used male rats from the specific inbred strains, Fisher 344 and Lewis, divided into 3 different groups (32 per group). ISO (isogeneic aortic transplantation, Fisher to Fisher); ALO (allogeneic aortic transplantation, Fisher to Lewis); ALO+THALID (allogeneic aortic transplantation treated with thalidomide (200mg/Kg/day/gavage)). The animals were followed during a period of 30 days and then sacrificed. The results showed that the standardizing of the experimental model of aortic transplantation was possible within a sequence highly accurate and reproducible methodology. As expected, the animals of the ISO showed no sign of graft rejection keeping the entire layered architecture of the vessel. On the other hand, the ALO group developed chronic transplant vasculopathy characterized by thickness of the intima and adventitia. Furthermore, ALO group animals showed increase of a-actin expression accompanied by an intense cellular proliferative activity, particularly in the neointima and adventitia layers, probably due to VSMC migration to the intima. Analysis by IH revealed intense infiltration of macrophages and T lymphocytes, as well as apoptosis in all layers of the allograft. The gene expression and tissue concentrations of the mediators of immune response TNF-a, IL-1b, IL-6, IL-2, INF-g, and IL-10 were also significantly higher in the ALO group. These findings were associated with the NFkB activation, as well as the involvement of p50 and p65 dimers. Treatment with thalidomide promoted a vascular protective effect by reducing the neointimal formation and local inflammation. Moreover, induced a decrease in the gene expression and tissue concentration of the inflammatory mediators TNF-a, IL-1b, IL-6, IL-2, INF-g, as well as increase of IL-4 and IL-10. Thalidomide also decreased the NFkB activation. Conclusion: the results of this study indicate that experimental model of chronic transplant vasculopathy is an appropriate model to study changes in the vessel layers during the process of allograft rejection. Thalidomide promoted a vascular protective effect, attenuating neointimal formation and local inflammation, as well as mediators of immune response, probably due to its anti-inflammatory and immunomodulatory properties
33

Novos híbridos derivados de hidroxiureia e talidomida induzem a produção de hemoglobina fetal e apresentam atividade anti-inflamatória / New hybrid derivates of hydroxyurea and thalidomide induce the production of fetal hemoglobin and have anti-inflammatory activity

Gambero, Sheley 19 August 2018 (has links)
Orientador: Fernando Ferreira Costa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T03:49:55Z (GMT). No. of bitstreams: 1 Gambero_Sheley_D.pdf: 3649073 bytes, checksum: a76d9a7da22f0e08a3f4556b9b24330f (MD5) Previous issue date: 2011 / Resumo: A anemia falciforme (AF) é um distúrbio genético da hemoglobina causado por uma mutação de ponto no gene da beta-globina com consequente produção de hemoglobina S (HbS). A polimerização de HbS causa a deformação, enrijecimento e diminuição da flexibilidade das hemácias, resultando em uma série de eventos que levam a redução da sua vida média. Os principais fatores que influenciam a polimerização são: concentração de oxigênio e concentração de hemoglobina fetal (HbF). Pacientes com AF apresentam aumento dos níveis circulantes de citocinas, incluindo fator de necrose tumoral-'alfa' (TNF-'alfa') que possui efeitos pró-inflamatórios resultando no aumento das propriedades quimiotáxicas e a aderência de neutrófilos ao endotélio vascular. Muitos estudos têm sido realizados com o intuito de buscar novas estratégias terapêuticas que contribuam para o aumento dos níveis de HbF e diminuam os níveis de citocinas inflamatórias. Com este objetivo, novos compostos que agregam funções anti-inflamatórias e são moléculas doadoras de óxido nítrico, foram desenvolvidas. Deste modo, o objetivo deste trabalho foi avaliar os efeitos dos compostos derivados da hidroxiureia e da talidomida na produção de HbF, na atividade quimiotática e na produção de espécies reativas de oxigênio em células de pacientes com anemia falciforme e indivíduos controles, tratadas com o composto denominado Lapdesf 1, assim como a concentração de citocinas inflamatórias, em culturas de células mononucleares de camundongos falciforme. Os resultados obtidos demonstram que o composto Lapdesf 1 foi capaz de aumentar os níveis de HbF em cultura de células CD34+ e em linhagem celular K562. Os neutrófilos de indivíduos controles e pacientes com AF, tratados com este composto apresentaram a capacidade quimiotática induzida por Il-8 significativamente reduzida em relação ao controle, e o tratamento com Lapdesf 1 não alterou a geração de espécies reativas de oxigênio em plaquetas, neutrófilos, eritrócitos e células mononucleares. O tratamento de camundongos transgênicos para a AF demonstrou a capacidade desse composto em aumentar os níveis de HbF, além de diminuir a quantidade de citocinas inflamatórias no sobrenadante de culturas de células mononucleares de camundongos. Em resumo nossos resultados sugerem que o composto Lapdesf 1, apresenta-se como uma nova alternativa terapêutica, pela capacidade de aumentar a síntese de HbF e diminuir os níveis de citocinas inflamatórias e seus efeitos, que merece ser testada como possível tratamento da anemia falciforme / Abstract: Sickle cell anemia is a genetic hemoglobin disorder caused by a point mutation that produces hemoglobin S (HbS). Polymerization of HbS causes deformation, stiffness and decreased flexibility of red blood cells, resulting in different events. The main factors influencing polymerization are: oxygen concentration and intracellular concentration of fetal hemoglobin (HbF). It has been reported that patients with sickle cell disease have increased circulating levels of cytokines, including tumor necrosis factor-'alfa' (TNF-'alfa') which has pro-inflammatory effects, resulting in increased chemotactic properties and adhesion of neutrophils to vascular endothelium. Many studies have been conducted in order to pursue new therapeutic strategies that increase fetal hemoglobin levels and lower levels of inflammatory cytokines. New compounds have been developed for the treatment of some sickle cell anemia symptoms. These compounds have several functions: they act as antiinflammatory agents, and donate nitric oxide. Thus the objectives of this study were to evaluate effects of compounds derived from hydroxyurea and thalidomide in the production of HbF, chemotactic activity and production of reactive oxygen species in cells from patients with sickle cell anemia and controls treated with the compound called Lapdesf1, and also the concentration of inflammatory cytokines in cultures of mononuclear cells from sickle cell mice. Our results demonstrate that the compound, Lapdesf 1, was able to increase levels of fetal hemoglobin in CD34+ cultured cells and K562 lineage cells. Neutrophils from control subjects and patients with sickle cell anemia had their chemotactic capacity significantly reduced following treatment with this compound; furthermore, the compound did not alter the generation of reactive oxygen species in platelets, neutrophils, red cells and mononuclear cells. Treatment of transgenic sickle cell anemia mice demonstrated the ability of the compound to increase fetal hemoglobin in vivo and reduce the amount of inflammatory cytokines such as TNF-'alfa', IL-8, IL-6 and IL- 1ß in the supernatant of cultures of mononuclear cells from sickle mice. In summary, our results suggest that the compound Lapdesf 1 has the ability to increase HbF synthesis and decrease the levels of inflammatory cytokines and their effects. So this compound may present promise as a new drug for the treatment of sickle cell disease, minimizing the clinical complications associated with this disease / Doutorado / Biologia Estrutural, Celular, Molecular e do Desenvolvimento / Doutor em Fisiopatologia Medica
34

Análise da efetividade do Centro de Referência Estadual do Hospital de Clínicas de Porto Alegre para tratamento do mieloma múltiplo

Saccilotto, Indara Carmanim January 2014 (has links)
Introdução: Os Centros de Referência (CR) são serviços especializados, parte de um projeto inovador de parceria entre a academia e os gestores do Sistema Único de Saúde (SUS). O principal objetivo de um CR é promover a assistência através de acompanhamento multidisciplinar, facilitando o acesso ao medicamento fornecido pelas Secretarias Estaduais de Saúde (SES). Objetivos: avaliar a efetividade da assistência de pacientes com Mieloma Múltiplo (MM) em um CR no âmbito do SUS (Centro de Referência para Mieloma Múltiplo do Hospital de Clínicas de Porto Alegre [CRMM-HCPA]); comparar a qualidade de vida entre portadores de MM atendidos no CRMM-HCPA e em outros serviços de saúde que não são CR. Metodologia: Foi realizado um estudo prospectivo de 6 meses, com participantes que recebiam a Talidomida pela SES-RS, e eram tratados pelo CRMM-HCPA, em comparação com os que recebiam tratamento em outras instituições, fora de um CR. Foram incluídos 32 participantes da pesquisa, sendo 19 do CRMM-HCPA e 13 participantes de outras instituições. Para análise da efetividade do CRMM-HCPA foi considerado como desfecho principal o tempo, a partir do diagnóstico, em que os participantes da pesquisa levaram para realização do Transplante Autólogo de Células Tronco Hematopoiéticas (TACTH), por ser considerado este a terapia “padrão ouro” para o MM. Para análise deste tempo, foram aplicados questionários específicos do estudo e para análise da qualidade de vida foi aplicado o questionário SF-36. Resultados: Na análise de qualidade de vida encontramos diferença significativa em relação ao item aspecto social (do SF-36), relacionado à realização de atividades sociais (P = 0,02). O tempo (em meses) a partir do diagnóstico até o transplante de medula óssea, em cada grupo, foi medido apenas em participantes da pesquisa com idade \65 anos (n=25), dos quais, nesta análise, 15 eram do HCPA e 10 das outras instituições. Encontramos diferença significativa (P=0,036) em relação ao tempo em que os participantes da pesquisa foram encaminhados para realizarem o transplante autólogo, demonstrando que os do CRMM (HCPA) são encaminhados para o transplante em tempo significativamente inferior (mediana: 9 meses; IIQ: 8,5 a 14,5) do que são atendidos nas demais instituições (mediana: 24 meses; IIQ: 16 a 24). Conclusões: Os participantes do CRMM demonstraram mais facilidade em executar atividades sociais, com menos interferências relacionadas a problemas físicos ou emocionais. O CRMM demonstrou ser uma estratégia de tratamento mais efetiva do que outros serviços de saúde do SUS, que não são CR, uma vez que permitiu uma redução do tempo para a realização do transplante. / Introduction:Within the Brazilian Unified Health System (SUS), Referral Centers (RCs) are care facilities that provide specialized services as part of an innovative partnership project between universities and SUS managers. The main goal of RCs is to promote care through a multidisciplinary approach, facilitating access to medicines supplied by state health departments (SHDs).Objectives:To evaluate the effectiveness of care provided to patients with multiple myeloma (MM) in a RC within SUS (Hospital de Clínicas de Porto Alegre Referral Center for Multiple Myeloma, CRMM-HCPA) and to compare quality of life between patients with MM treated at CRMM-HCPA and other non-RC health care facilities. Methods: A 6-month prospective cohort study was conducted in patients receiving thalidomide from the Rio Grande do Sul SHD (SHD-RS) and treated at CRMM-HCPA, as compared to patients receiving treatment at other non-RC health care facilities. Thirty-two patients were included in the study, 19 from CRMM-HCPA and 13 from other institutions. To analyze the effectiveness of CRMM-HCPA, the main outcome measure was the time from diagnosis to referral for autologous hematopoietic stem cell transplantation (HSCT), as this is considered the gold-standard treatment for MM. Time from diagnosis to referral for autologous HSCT was assessed using questionnaires specifically designed for this study, and quality of life was assessed using the SF-36 questionnaire. Results: On quality of life analysis, there was a significant difference in the “social functioning” domain of the SF-36 questionnaire, which relates to performance of social activities (P=0.02). The time (in months) from diagnosis to referral for autologous HSCT, in each group, was measured only in patients aged \65 years (n=25); of these, 15 were from CRMM-HCPA and 10 from other institutions. In this analysis, there was a significant difference (P=0.036) in time between diagnosis and referral for autologous HSCT, which was significantly shorter for patients treated at CRMM-HCPA (median, 9 months; IQR, 8.5–14.5) than for those treated elsewhere (median, 24 months; IQR, 16–24).Conclusions:Patients treated at CRMM-HCPA demonstrated greater ease in performing social activities, with less interference from physical or emotional problems. CRMM-HCPA offers a more effective treatment strategy as compared with other non-RC health care facilities, as it enabled a reduction in time to transplantation.
35

Percutaneous delivery of thalidomide and its N-alkyl analogues for treatment of rheumatoid arthritis / Colleen Goosen

Goosen, Colleen January 1998 (has links)
Rheumatoid arthritis (RA) is a chronic inflammatory joint disease associated with high levels of tumour necrosis factor-alpha (TNF-a) in synovial fluid and synovial tissue (Saxne et al., 1989). Thalidomide is a proven inhibitor of the biological synthesis of TNF-a (Sampaio et al., 1991) and is believed to rely on this action for its suppression of the wasting of tissue which accompanies RA. Oral administration of thalidomide has proven to be effective in RA, but unacceptable side effects are easily provoked (Gutierrez-Rodriguez, 1984). Administration of thalidomide via the dermal route can down-regulate TNF-a production in and around the affected joint, and this without raising the systemic blood level to a problematical level. Based on thalidomide's physicochemical properties, it is unlikely that it can be delivered percutaneously at a dose required for RA. Therefore, we have embraced the idea of using N-alkyl analogues of thalidomide. The most important feature that an analogue of this compound might contribute is decreased crystallinity and increased lipophilicity. Ordinarily both these parameters should favour percutaneous delivery. The current study was primarily aimed at exploring the feasibility of percutaneous delivery of thalidomide and subsequently, three of its odd chain IV-alkyl analogues (methyl, propyl and pentyl) via physicochemical characterization and assessment of their innate abilities to diffuse through skin as an initial step towards developing a topical dosage form for the best compound. The biological activities, more specifically their potential to inhibit the production of TNF-a was determined for thalidomide and its N-alkyl analogues. In order to achieve the objectives, the study was undertaken by synthesizing and determining the physicochemical parameters of thalidomide and its N-alkyl analogues. A high level of crystallinity is expressed in the form of a high melting point and heat of fusion. This limits solubility itself, and thus also sets a limit on mass transfer across the skin. Generally, the greater a drug's innate tendency to dissolve, the more likely it is that the drug can be delivered at an appropriate rate across the skin (Ostrenga et al., 1971). Therefore, the melting points and heats of fusion were determined by differential scanning calorimetry. Aqueous solubility and the partition coefficient (relative solubility) are major determinants of a drug's dissolution, distribution and availability. N-octanollwater partition coefficients were determined at pH 6.4. Solubilities in water, a series of n-alcohols and mixed solvents were obtained, as well as the solubility parameters of the compounds in study. Secondly, in vitro permeation studies were performed from these solvents and vehicles using vertical Franz diffusion cells with human epidermal membranes. Thirdly, tumour necrosis factor-alpha (TNF-a) inhibition activities were assessed for thalidomide and its N-alkyl analogues. By adding a methyl group to the thalidomide structure, the melting point drops by over 100°C and, in this particular instance upon increasing the alkyl chain length to five -CH2- units the melting points decrease linearly. Heats of fusion decreased dramatically upon thalidomide's alkylation as well. Methylation of the thalidomide molecule enhanced the aqueous solubility 6-fold, but as the alkyl chain length is further extended from methyl to pentyl, the aqueous solubility decreased exponentially. The destabilization of the crystalline structure with increasing alkyl chain length led to an increase in lipophilicity and consequently an increase in solubility in nonpolar media. Log partition coefficients increased linearly with increasing alkyl chain length. Solubilities in a series of n-alcohols, methanol through dodecanol, were found to be in the order of pentyl > propyl > methyl > thalidomide. The N-alkyl analogues have more favourable physicochemical properties than thalidomide to be delivered percutaneously. The in vitro skin permeation data proved that the analogues can be delivered far easier than thalidomide itself. N-methyl thalidomide showed the highest steady-state flux through human skin from water, n-alcohols and combination vehicles. Thalidomide and its N-alkyl analogues were all active as TNF-a inhibitors. Finally, active as a TNF-a inhibitor, N-methyl thalidomide is the most promising candidate to be delivered percutaneously for treatment of rheumatoid arthritis, of those studied. / Thesis (PhD (Pharmaceutics))--PU for CHE, 1999.
36

Paclitaxel potencia a hipernocicepÃÃo inflamatÃria: evidÃncias da participaÃÃo de citocinas e do receptor toll tipo 4 (TLR-4) / Paclitaxel enhances the inflammatory hypernociception: evidence of involvement of cytokines and Toll-like receptor 4 (TLR-4)

Mirlane GuimarÃes de Melo Cardoso 07 January 2009 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / nÃo hà / Paclitaxel (PCX) foi o 1 antineoplÃsico efetivo no tratamento de cÃnceres refratÃrios a quimioterapia convencional. Clinicamente, induz artralgias e mialgias de carÃter incapacitante que comprometem a qualidade de vida e limitam o tempo de tratamento antitumoral, acometendo atà 57% dos doentes. Apesar destas repercussÃes clÃnicas nada foi descrito atà o momento, visando elucidar o envolvimento de citocinas prÃ-inflamatÃrias, na gÃnese da atividade hipernociceptiva do PCX, jà que a droga compartilha com o LPS uma via de sinalizaÃÃo desencadeada por receptores Toll (TLR-4 e TLR-2) para geraÃÃo de genes que codificam TNF-&#945;. Dados da literatura sugerem que ocorra um âcross-talkâ entre esses dois membros da famÃlia Toll e, que agonistas diferentes de TLR-2 e TLR-4 sÃo capazes de induzir a ativaÃÃo de NF-&#945;B, AP1 e MAP kinase e a geraÃÃo de TNF-&#945;, citocina chave na cascata de liberaÃÃo de mediadores inflamatÃrios finais que atuam diretamente no nociceptor. Dados do laboratÃrio registraram que o zymosan (ZY) intrarticular em joelhos de ratos produz uma periartrite caracterÃstica da hipernocicepÃÃo no teste de incapacitaÃÃo articular (IA), e que PCX (8mg/kg) amplificou essa resposta quando se injetou  da dose do ZY. Tal amplificaÃÃo foi inibida com o prÃ-tratamento com inibidores de citocina e de prostanÃides. Objetivo. Investigar a participaÃÃo do TLR-4 e TNF-&#945; na gÃnese do efeito potencializador do PCX na artralgia experimental induzida por ZY. Material e MÃtodos. Ratos foram prÃ-tratados Sc com talidomida (TLD), pentoxifilina, dexametasona, indometacina ou celecoxib e estimulados com subdose de ZY (250&#956;g/animal; i-art). ApÃs a 1 medida do tempo de suspensÃo de pata (TSP) no teste de IA, os animais receberam PCX (8mg/kg; ip). Numa segunda etapa os ratos receberam durante trÃs dias consecutivos o prÃ-tratamento com atorvastatina (3, 10, 30mg/kg/dia; VO). Os seguintes parÃmetros foram avaliados: modulaÃÃo da hipernocicepÃÃo no teste de incapacitaÃÃo articular, dosagem de citocinas em lavado de joelho de ratos (TNF-&#945;, IL-1&#945;, Il-6, KC e CINC) e imunohistoquÃmica para TNF-&#945;, IL-1&#945; e TLR-4 no tecido sinovial. Resultados. Ficou demonstrado que PCX (8mg/kg) potencializa a artralgia experimental induzida por ZY em ratos avaliada pelo aumento significativo do TSP (p<0,001) na 4Âh de artrite em relaÃÃo ao controle no teste de IA. Tal efeito foi inibido de maneira significativa pelo prÃ-tratamento com TLD (45mg/kg) e essa inibiÃÃo foi associada à reduÃÃo dos nÃveis de TNF-&#945; produzido pelas cÃlulas do tecido sinovial no lavado articular e da marcaÃÃo imunohistoquÃmica para TNF-&#61537;. Da mesma forma a inibiÃÃo dessa resposta amplificadora do PCX foi ratificado pelo prÃ-tratamento com atorvastatina nas trÃs doses utilizadas no modelo, tambÃm sendo associado à diminuiÃÃo significativa dos nÃveis de TNF-&#61537; no lavado articular e visÃvel reduÃÃo na marcaÃÃo imunohistoquÃmica para TNF-&#61537;, IL-1&#61538; e TLR-4, nas trÃs doses utilizadas. ConclusÃes. PCX potencializa a hipernocicepÃÃo induzida por ZY por um mecanismo indireto sobre cÃlulas residentes da membrana sinovial que liberam TNF-&#61537; provavelmente pela ativaÃÃo da NF-&#61547;B via TLR-4/MD2, pois esse efeito potencializador foi inibido pela atorvastatina, um provÃvel antagonista de TLR-4. O TNF-&#61537; liberado age iniciando a cascata de mediadores envolvidos com a dor inflamatÃria, o que justifica em parte as artralgias dos pacientes em tratamento com PCX. / Paclitaxel (PCX) was the first effective antineoplastic medicine in the treatment of tumors that do not respond to conventional chemotherapy. Clinically, it induces incapacitating arthralgias and myalgias that interfere with the patient quality of life and limit the duration of the treatment. This is observed in up to 57% of the patients using the drug. Despite these clinical manifestations, nothing has been published that could explain the involvement of pro-inflammatory cytokines in the triggering of the hypernociceptive effect of PCX, even though it is known that the drug shares with LPS a signaling pathway started by Toll-like receptors (TLR-2 and TLR-4) that activates genes coding for TNF-&#945;. The literature suggests that there is a crosstalk between these two members of the Toll family and that different agonists of TLR-2 and TLR-4 are able to induce the activation of NF-kB, AP1 and MAP kinase in the generation of TNF-&#945;, a key cytokines in the cascade liberating the final inflammatory mediators that act directly on the nociceptor. Data obtained in laboratory show that the injection of zymozan into rat knee-joints produces a periarthritis characteristic of the hypernociception seen in the knee joint incapacitation test and that PCX (8mg/kg) amplified the response when  of the zymozan (ZY) doses was injected. The amplification was inhibited when animals were pre-treated with inhibitors of cytokines and prostanoids. Objective: To study the role of TNF-&#945; and TLR-4 on the initiation of the potentiating effect of PCX on the experimental arthralgia induced by ZY. Material and Methods: Rats were pre-treated Sc with thalidomide, pentoxifiline, dexametazone, indometacin and celecoxib and then stimulated with an intra-articular subdoses of ZY (250&#956;g/animal). After the first measurement of the paw elevation time in the knee joint incapacitation test, the animals were treated with PCX (8mg/kg ip). On a second trial, rats were treated for three consecutive days with atorvastatin (3, 10, 30mg/kg/day; VO). The following parameters were evaluated: modulation of the effect on the knee joint incapacitation test (JIT), amount of cytokines in the ratâs knee lavage (TNF-&#945;, IL-1 &#946;, IL-6, KC and CINC) and immunohistochemistry for TNF-&#945;, IL-1&#946; and TLR-4 on synovial tissue. Results: It was shown that PCX (8mg/kg) potentiates the experimental arthralgia induced by ZY in the rats as evaluated by the significant increase in paw elevation time (p<0.001) at the 4th h of arthritis in relations to controls. Such effect was significantly inhibited by pre-treatment with thalidomide (45mg/kg) and the inhibition was associated with a decrease in the amount of TNF-&#945; produced by synovial tissue cells and detected in the joint lavage and in the immunohistochemistry for TNF-&#945;. Likewise the inhibition of the amplifying response to PCX was seen with pre-treatment with atorvastatin at the three doses used in the experiment, which was also associated with a lower TNF-&#945; in the joint lavage and perceptible decrease in the immunohistochemistry for TNF-&#945;, IL-1&#946; and TLR-4. Conclusions: PCX potentiates the hypernociception induced by ZY through an indirect effect on synovial membrane resident cells that release TNF-&#945; probably through activation of the NF-kB pathway by TLR-4/MD2, since the potentiating effect was inhibited by atorvastatin, a TLR-4 antagonist. Released TNF-&#945; act starting the cascade of mediators involved in the inflammatory pain and this partially explains the arthralgia in patients treated with PCX.
37

Percutaneous delivery of thalidomide and its N-alkyl analogues for treatment of rheumatoid arthritis / Colleen Goosen

Goosen, Colleen January 1998 (has links)
Thesis (PhD (Pharmaceutics))--PU for CHE, 1999.
38

Percutaneous delivery of thalidomide and its N-alkyl analogues for treatment of rheumatoid arthritis / Colleen Goosen

Goosen, Colleen January 1998 (has links)
Rheumatoid arthritis (RA) is a chronic inflammatory joint disease associated with high levels of tumour necrosis factor-alpha (TNF-a) in synovial fluid and synovial tissue (Saxne et al., 1989). Thalidomide is a proven inhibitor of the biological synthesis of TNF-a (Sampaio et al., 1991) and is believed to rely on this action for its suppression of the wasting of tissue which accompanies RA. Oral administration of thalidomide has proven to be effective in RA, but unacceptable side effects are easily provoked (Gutierrez-Rodriguez, 1984). Administration of thalidomide via the dermal route can down-regulate TNF-a production in and around the affected joint, and this without raising the systemic blood level to a problematical level. Based on thalidomide's physicochemical properties, it is unlikely that it can be delivered percutaneously at a dose required for RA. Therefore, we have embraced the idea of using N-alkyl analogues of thalidomide. The most important feature that an analogue of this compound might contribute is decreased crystallinity and increased lipophilicity. Ordinarily both these parameters should favour percutaneous delivery. The current study was primarily aimed at exploring the feasibility of percutaneous delivery of thalidomide and subsequently, three of its odd chain IV-alkyl analogues (methyl, propyl and pentyl) via physicochemical characterization and assessment of their innate abilities to diffuse through skin as an initial step towards developing a topical dosage form for the best compound. The biological activities, more specifically their potential to inhibit the production of TNF-a was determined for thalidomide and its N-alkyl analogues. In order to achieve the objectives, the study was undertaken by synthesizing and determining the physicochemical parameters of thalidomide and its N-alkyl analogues. A high level of crystallinity is expressed in the form of a high melting point and heat of fusion. This limits solubility itself, and thus also sets a limit on mass transfer across the skin. Generally, the greater a drug's innate tendency to dissolve, the more likely it is that the drug can be delivered at an appropriate rate across the skin (Ostrenga et al., 1971). Therefore, the melting points and heats of fusion were determined by differential scanning calorimetry. Aqueous solubility and the partition coefficient (relative solubility) are major determinants of a drug's dissolution, distribution and availability. N-octanollwater partition coefficients were determined at pH 6.4. Solubilities in water, a series of n-alcohols and mixed solvents were obtained, as well as the solubility parameters of the compounds in study. Secondly, in vitro permeation studies were performed from these solvents and vehicles using vertical Franz diffusion cells with human epidermal membranes. Thirdly, tumour necrosis factor-alpha (TNF-a) inhibition activities were assessed for thalidomide and its N-alkyl analogues. By adding a methyl group to the thalidomide structure, the melting point drops by over 100°C and, in this particular instance upon increasing the alkyl chain length to five -CH2- units the melting points decrease linearly. Heats of fusion decreased dramatically upon thalidomide's alkylation as well. Methylation of the thalidomide molecule enhanced the aqueous solubility 6-fold, but as the alkyl chain length is further extended from methyl to pentyl, the aqueous solubility decreased exponentially. The destabilization of the crystalline structure with increasing alkyl chain length led to an increase in lipophilicity and consequently an increase in solubility in nonpolar media. Log partition coefficients increased linearly with increasing alkyl chain length. Solubilities in a series of n-alcohols, methanol through dodecanol, were found to be in the order of pentyl > propyl > methyl > thalidomide. The N-alkyl analogues have more favourable physicochemical properties than thalidomide to be delivered percutaneously. The in vitro skin permeation data proved that the analogues can be delivered far easier than thalidomide itself. N-methyl thalidomide showed the highest steady-state flux through human skin from water, n-alcohols and combination vehicles. Thalidomide and its N-alkyl analogues were all active as TNF-a inhibitors. Finally, active as a TNF-a inhibitor, N-methyl thalidomide is the most promising candidate to be delivered percutaneously for treatment of rheumatoid arthritis, of those studied. / Thesis (PhD (Pharmaceutics))--PU for CHE, 1999.
39

Controle de qualidade e avaliação das propriedades tecnológicas das formas polimórficas de talidomida / Quality control and evaluation of technological properties of polymorphic forms of thalidomide

Silva, Ana Paula Cappra January 2011 (has links)
A talidomida foi amplamente prescrita entre 1950 e 1960, em quase 50 países, como hipnosedativo não-barbitúrico e antiemético para indisposição matinal durante a gravidez, sendo em seguida fortemente controlada em função da ocorrência de sérios problemas de teratogenicidade. Nos últimos anos, vários esforços foram realizados no sentido de buscar identificar e elucidar as propriedades antiinflamatórias, imunomodulatórias e antiangiogênicas da talidomida. Na mesma direção, investigações clínicas foram conduzidas em pacientes com diversas doenças, como mieloma múltiplo, carcinoma renal, câncer de próstata, Síndrome da rejeição paciente-enxerto, entre outras. A talidomida possui um centro quiral e dois anéis amida em sua estrutura e é sintetizada como racemato, constituída por dois enantiômeros ativos: (+)-(R)- e (+)-(S)-talidomida. A talidomida racêmica apresenta duas formas polimórficas, alfa ( ) e beta ( ). Assim, a variabilidade observada em relação ao polimorfismo representa um ponto crítico se considerarmos o potencial de alteração de propriedades biofarmacêuticas em decorrência da predominância de um ou outro polimorfo. No Brasil o medicamento talidomida é fabricado exclusivamente pela FUNED – Fundação Ezequiel Dias, laboratório público do Estado de Minas Gerais que integra o Sistema Oficial de produção de Medicamentos do País. Neste contexto, este trabalho tem como principal objetivo a avaliação de características físicas, físico-químicas e tecnológicas dos polimorfos da talidomida, com ênfase nos ensaios de cristalização, dissolução, degradação e compressão. Os resultados deste trabalho contribuíram para um melhor entendimento da relação entre características cristalográficas e propriedades farmacêuticas, agregando uma base científica capaz de avaliar as diferenças existentes destes polimorfos e garantir o controle de qualidade adequado do produto final produzido em um Laboratório Oficial. Estes estudos contribuíram para o cumprimento de exigências regulatórias. / Thalidomide was widely prescribed between 1950 and 1960, in nearly 50 countries, as sedative and antiemetic for morning sickness during pregnancy. After the occurrence of serious problems of teratogenicity it was heavily controlled. Growing interest has been observed in recent years to identify and elucidate the anti-inflammatory, immunomodulatory and anti-angiogenic properties of thalidomide. In the same direction, clinical investigations have been conducted in patients with various diseases such as myeloma, renal carcinoma, and prostate cancer, among others. Thalidomide possesses a chiral center and two amide rings in its structure and is synthesized as racemate, consisting of two active enantiomers: (+)-(R)- and (+)-(S)-thalidomide. It is known that the racemic thalidomide has two polymorphic forms, alpha ( ) and beta ( ). Thus, the observed variability in relation to the polymorphism represents a critical point considering the potential of changes in biopharmaceutical properties due to the predominance of one of them. In Brazil thalidomide tablets are manufactured exclusively by FUNED – Fundação Ezequiel Dias, the public laboratory of the State of Minas Gerais, which integrates the Country's Official System of drug production. In this context, the objectives of this work are the assessment of physical characteristics, physicalchemical and technological properties of polymorphic forms of thalidomide, with emphasis on crystallization, dissolution, degradation and compression. The results of this work contributed to a better understanding of the relationship between characteristic crystallographic properties and pharmaceutical properties, aggregating a scientific basis to assess the differences of these polymorphs and ensure the appropriate quality control of the final product produced in an official laboratory. These studies contributed to compliance with regulatory requirements.
40

Controle de qualidade e avaliação das propriedades tecnológicas das formas polimórficas de talidomida / Quality control and evaluation of technological properties of polymorphic forms of thalidomide

Silva, Ana Paula Cappra January 2011 (has links)
A talidomida foi amplamente prescrita entre 1950 e 1960, em quase 50 países, como hipnosedativo não-barbitúrico e antiemético para indisposição matinal durante a gravidez, sendo em seguida fortemente controlada em função da ocorrência de sérios problemas de teratogenicidade. Nos últimos anos, vários esforços foram realizados no sentido de buscar identificar e elucidar as propriedades antiinflamatórias, imunomodulatórias e antiangiogênicas da talidomida. Na mesma direção, investigações clínicas foram conduzidas em pacientes com diversas doenças, como mieloma múltiplo, carcinoma renal, câncer de próstata, Síndrome da rejeição paciente-enxerto, entre outras. A talidomida possui um centro quiral e dois anéis amida em sua estrutura e é sintetizada como racemato, constituída por dois enantiômeros ativos: (+)-(R)- e (+)-(S)-talidomida. A talidomida racêmica apresenta duas formas polimórficas, alfa ( ) e beta ( ). Assim, a variabilidade observada em relação ao polimorfismo representa um ponto crítico se considerarmos o potencial de alteração de propriedades biofarmacêuticas em decorrência da predominância de um ou outro polimorfo. No Brasil o medicamento talidomida é fabricado exclusivamente pela FUNED – Fundação Ezequiel Dias, laboratório público do Estado de Minas Gerais que integra o Sistema Oficial de produção de Medicamentos do País. Neste contexto, este trabalho tem como principal objetivo a avaliação de características físicas, físico-químicas e tecnológicas dos polimorfos da talidomida, com ênfase nos ensaios de cristalização, dissolução, degradação e compressão. Os resultados deste trabalho contribuíram para um melhor entendimento da relação entre características cristalográficas e propriedades farmacêuticas, agregando uma base científica capaz de avaliar as diferenças existentes destes polimorfos e garantir o controle de qualidade adequado do produto final produzido em um Laboratório Oficial. Estes estudos contribuíram para o cumprimento de exigências regulatórias. / Thalidomide was widely prescribed between 1950 and 1960, in nearly 50 countries, as sedative and antiemetic for morning sickness during pregnancy. After the occurrence of serious problems of teratogenicity it was heavily controlled. Growing interest has been observed in recent years to identify and elucidate the anti-inflammatory, immunomodulatory and anti-angiogenic properties of thalidomide. In the same direction, clinical investigations have been conducted in patients with various diseases such as myeloma, renal carcinoma, and prostate cancer, among others. Thalidomide possesses a chiral center and two amide rings in its structure and is synthesized as racemate, consisting of two active enantiomers: (+)-(R)- and (+)-(S)-thalidomide. It is known that the racemic thalidomide has two polymorphic forms, alpha ( ) and beta ( ). Thus, the observed variability in relation to the polymorphism represents a critical point considering the potential of changes in biopharmaceutical properties due to the predominance of one of them. In Brazil thalidomide tablets are manufactured exclusively by FUNED – Fundação Ezequiel Dias, the public laboratory of the State of Minas Gerais, which integrates the Country's Official System of drug production. In this context, the objectives of this work are the assessment of physical characteristics, physicalchemical and technological properties of polymorphic forms of thalidomide, with emphasis on crystallization, dissolution, degradation and compression. The results of this work contributed to a better understanding of the relationship between characteristic crystallographic properties and pharmaceutical properties, aggregating a scientific basis to assess the differences of these polymorphs and ensure the appropriate quality control of the final product produced in an official laboratory. These studies contributed to compliance with regulatory requirements.

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