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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.
11

Análise da presença de citocinas no periodonto de ratos diabéticos tratados com chá verde / Cytokines expression analyses in periodontium of diabetic rats treated with green tea

Gabriela Gennaro 30 March 2012 (has links)
As doenças periodontais (DPs) são alterações inflamatórias crônicas que acometem os tecidos de sustentação do órgão dental. A presença do diabetes é refletida em maior severidade e prevalência das DPs tanto em humanos quanto em modelos experimentais. Contudo, os mecanismos biológicos envolvidos no aumento da prevalência e da severidade permanecem pouco conhecidos. Desta forma, o objetivo deste estudo foi avaliar o número de células marcadas por imunohistoquímica para TNF-&#x3B1;, RANKL, OPG, IL-10 e para o fator de transcrição RUNX-2, na doença periodontal experimental decorrente da indução do diabetes em ratos. Além disso, avaliamos os possíveis efeitos do tratamento com chá verde sobre o periodonto dos animais. Inicialmente, os ratos (n=80) foram submetidos à indução do diabetes por administração intraperitoneal de estreptozotocina (50mg/kg) e, juntamente com o grupo controle (n=40), foram subdivididos em animais tratados com chá verde ou com água, acompanhados durante o período de 15, 30, 60 ou 90 dias. Após o sacrifício dentro do tempo determinado para cada grupo, as hemimaxilas coletadas passaram pelos procedimentos de imunohistoquímica. Os resultados revelaram que a presença do diabetes causou perda óssea alveolar, compatível com o desenvolvimento da doença periodontal e resultou em alterações significativas no número de células imunomarcadas para diferentes mediadores do processo inflamatório. Entretanto, o chá verde apresentou efeitos benéficos para o periodonto, alterando a marcação das citocinas envolvidas. Nos animais diabéticos, independente do tratamento, foi observado aumento estatisticamente significativo (p<0,05 ANOVA) no número de células imunomarcadas para TNF-&#x3B1; e RANKL. Inversamente, houve menor marcação para OPG (60 e 90 dias), RUNX-2 (30, 60 e 90 dias) e para IL-10 (30, 60 e 90 dias) nos animais que ingeriram água. Porém, os diabéticos tratados com chá não demonstraram diferenças significativas em relação ao seu respectivo controle. Assim, quando comparados os grupos diabéticos tratados com água e chá, os animais que receberam o chá demonstraram significativamente (p<0,05 ANOVA) menor quantidade de células munomarcadas para TNF-&#x3B1; e RANKL em relação aqueles diabéticos tratados com água, enquanto que a marcação para OPG, RUNX-2 e IL-10 foi maior. Portanto, a desregulação na expressão de citocinas e do fator de transcrição osteoblástico parece ser um dos mecanismos biológicos envolvidos no aumento da prevalência e da severidade das doenças periodontais decorrentes do diabetes. Entretanto, o chá verde modulou a inflamação no periodonto dos animais diabéticos, apresentando-se, possivelmente, como uma alternativa terapêutica e coadjuvante ao tratamento das doenças periodontais correlacionadas ao diabetes. / Periodontal diseases (PD) are chronic inflammatory diseases leading the destruction of connective tissue and alveolar bone supporting the teeth. The establishment of diabetes increases PD prevalence and severity in humans and experimental model. However, biological mechanisms regarding to increase of prevalence and severity remains poorly known. The aim of this study was to evaluate the number of immuno-staining cells to TNF-&#x3B1;, RANKL, OPG, IL-10 and transcription factor RUNX-2 in experimental periodontal disease in diabetic rats. Furthermore, the possible green tea efects were evaluated in periodontiumof the rats. Diabetes was induced in Wistar rats (n=120) by intraperitoneal administration of 50 mg/kg ofstreptozotocin and together with control animals (n=80), the rats were subdivided in water or green tea treated group, that were analyzed at 15, 30, 60 and 90 days after diabetes induction. The animals were sacrificed and the hemimaxillae were removed and submitted to immunohistochemistry procedures. Our data demonstrated that diabetes induction and progression resulted in significant bone loss and alterations in number of immuno-staining cells to different mediators of inflammatory process. However, the green tea showed positive effects in periodontium through inflammation modulation. In diabetic rats, regardless of treatment, we observed an increased number of immuno-staining cells to TNF-&#x3B1;, IL-1b and RANKL (p<0,05 ANOVA). On the other hand, in water treated diabetic rats, there were a decreased number of immuno-staining cells to OPG (60 e 90 days), RUNX-2 (30, 60 e 90 days) and IL-10 (30, 60 e 90 days). However, the green tea treated rats did not showed statistical differences between control and experimental groups in those staining. When we compared both diabetic groups, green tea and water treated, the animals that drank the green tea showed decreased number of immuno-staining cells to TNF-&#x3B1; and RANKL(p<0,05 ANOVA) whereas the number of immuno-staining cells to OPG, RUNX-2 e IL-10 were increased. Taken together, desregulation of inflammatory cytokines and osteoblastic transcripition factor seem to be one of biological mechanisms involved in the increase of periodontal disease prevalence and severity associated with diabetes. However the green tea was able to modulate inflammation in diabetic rats periodontium and it seems to be a possible terapeutic agent to periodontal disease treatment associated with diabetes.
12

Participação do receptor de potencial transiente vanilóide do tipo 4 (TRPV4) e do melastatina do tipo 8 (TRPM8) nas disfunções miccionais do diabetes em camundongos / Participation of transient receptor potential vanilloid type 4 (TRPV4) and melastatin type 8 (TRPM8) in micturition dysfunction of diabetic mice

Ramos-Filho, Antonio Celso Saragossa, 1985- 25 August 2018 (has links)
Orientador: Edson Antunes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-25T08:00:03Z (GMT). No. of bitstreams: 1 Ramos-Filho_AntonioCelsoSaragossa_D.pdf: 3024613 bytes, checksum: a03a80c65d863acd441249f461461216 (MD5) Previous issue date: 2014 / Resumo: Os receptores TRPV4 e TRPM8 são expressos no urotélio e em fibras aferentes sensitivas da bexiga. Fisiologicamente, a ativação mecânica do receptor TRPV4 na parede da bexiga participa do controle miccional. Em doenças de origem inflamatória, esses receptores adquirem funcionalidade importante. As disfunções da bexiga no diabetes podem estar associadas a alterações ao nível de detrusor, inervação e urotélio. A disfunção urotelial parece ser a responsável por desencadear as alterações neurais e musculares da bexiga. Assim, o objetivo do presente estudo foi investigar os mecanismos fisiopatológicos da ativação dos receptores TRPV4 e TRPM8 no estado diabético em camundongos. Para tanto, dividimos o estudo em duas etapas, sendo que na primeira avaliamos a participação dos receptores TRPV4 e TRPM8 nos mecanismos contráteis e relaxantes do detrusor isolado de animais controles e knockout para esses canais. Em uma segunda etapa estudamos a ativação desses canais em camundongos diabéticos pela injeção intraperitoneal de estreptozotocina (180 mg/Kg) por 4 semanas. Em fragmentos do detrusor isolados de camundongos mostramos que o agonista do receptor TRPV4, GSK1016790A, causou resposta contrátil dependente da concentração. Por outro lado, quando os tecidos foram contraídos com solução despolarizante de KCl, o GSK1016790A causou relaxamento da preparação. No detrusor isolado de animais TRPV4-/- verificamos hipercontratilidade ao carbacol (agonista muscarínico) e à estimulação elétrica, assim como redução no relaxamento ao agonista ?-adrenérgico não-seletivo, isoprenalina. Estes efeitos não foram obtidos com os antagonistas dos receptores TRPV4, RN1734 e HC067047. A indução do diabetes causou nocicepção mecânica e aumento da proporção entre bexiga e peso corpóreo após 4 semanas da injeção. A avaliação miccional dos animais diabéticos mostrou aumento da capacidade, frequência urinária e das contrações involuntárias da bexiga. Observamos ainda hipercontratilidade do detrusor ao carbacol, à estimulação elétrica e ao KCl. A indução do diabetes em animais TRPV4-/- não modificou as disfunções "in vivo" e "in vitro" observadas nos animais wyld type diabéticos, mostrando que a ausência crônica dos receptores TRPV4 desencadeia alterações miccionais que são anteriores as causadas pelo diabetes. Também verificamos que os animais TRPM8-/- não apresentam alteração na resposta contrátil ao carbacol e à estimulação elétrica. Por outro lado, o mentol, mas não a icilina, reduziu significativamente as respostas contráteis nestes animais. O mentol inibiu o influxo de cálcio extracelular em cultura de células da musculatura lisa da bexiga por mecanismo inibitório direto nos canais Cav1.2. O tratamento agudo com mentol, intraperitoneal e intravesical, atenuou as disfunções miccionais observadas nos camundongos diabéticos. "In vitro" o pré-tratamento com mentol reduziu a hipercontratilidade ao carbacol no grupo diabético, sem alterar a resposta no grupo controle. Concluímos que o mentol impede a resposta contrátil da bexiga por mecanismo independente do receptor TRPM8 bloqueando o influxo de cálcio extracelular nos canais Cav1,2, podendo ser utilizado como tratamento na hiperatividade de bexiga de origem miogênica / Abstract: The TRPV4 and TRPM8 receptors are expressed in bladder urothelium and sensitive afferent fibers. Physiologically, the mechanical activation of TRPV4 receptor in the bladder wall is involved in micturition control. In inflammatory diseases, these receptors may have important roles. The bladder dysfunction in diabetes may be associated with changes at the level of detrusor, innervation and urothelium. The urothelial dysfunction triggers neural changes, modifying consequently the smooth muscle contractility. Thus, the goal of the present study was to investigate the pathophysiological mechanisms of TRPV4 and TRPM8 receptor activation in physiological and diabetic conditions in mice. For this purpose we divided the study in two phases, the first of which we evaluated the participation of TRPV4 and TRPM8 receptors in detrusor contractile and relaxing mechanisms in control and knockout animals for these channels. In the second phase we studied the activation of these channels in diabetic mice induced by intraperitoneal injection of streptozotocin (STZ; 180 mg / kg, 4 weeks). The TRPV4 agonist GSK1016790A produced concentration-dependent detrusor contractions. On the other hand, in detrusor pré-contracted with KCl (80 mM), GSK1016790A caused relaxation responses. In TRPV4-/- animals, we verified hypercontractility to carbachol (muscarinic agonist) and electrical-field stimulation, as well as a decreased relaxation to isoprenaline (non-selective ?-adrenergic agonist). These effects were not obtained with the TRPV4 antagonists, RN1734 and HC067047. Induction of diabetes with STZ caused hyperglycemia, mechanical nocicepton, and increased ratio between bladder and body weight after 4 weeks. The miccturition evaluationin diabetic animals showed increased capacity, urinary frequency, and non-voiding contractions. Hypercontractility to carbachol, electrical-field stimulation and KCl in isolated detrusor were lso observed. The induction of diabetes in TRPV4-/- animals did not change the urinary dysfunctions. Our data are consistent with the proposal that TRPV4 receptor has a physiological function in micturition control by decreasing muscarinic-induced contractions and increasing ?-adrenergic-mediated relaxations. Moreover, the bladder contractions to carbachol and EFS in TRPM8-/- did not significantly change compared to TRPM8+/+. However, menthol (300 ?M), but not icilin (1 ?M), significantly inhibited these contractile responses. The menthol (300 ?M) inhibited extracellular calcium influx in bladder smooth muscle cell culture by direct mechanism though Cav1.2 channels. In addition the acute treatment with menthol, intraperitoneal and intravesical, atenuated the micturition dysfunctions observed in diabetic mice. Also, detrusor preparations pre-treated with menthol decreased carbachol hypercontractility, without changing the responses in normoglycemic group. Menthol reduces bladder contractions by mechanisms independent of TRPM8 receptor activation, inhibiting extracellular calcium influx through Cav1.2 channel, thus been considered as treatment for bladder overactivity of myogenic origin / Doutorado / Farmacologia / Doutor em Farmacologia
13

Examining the protective effects of sesamol on oxidative stress associated blood-brain barrier dysfunction in streptozotocin-induced diabetic rats

VanGilder, Reyna. January 2009 (has links)
Thesis (Ph. D.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xi, 165 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 131-163).
14

A ativação do sistema NF-kappa B promove inflamação e lesão glomerular na doença renal diabética experimental. / NF-kappa B activation promotes glomerular injury and inflammation in experimental diabetic kidney

Foresto Neto, Orestes 21 January 2019 (has links)
Altas concentrações de glicose podem ativar a sinalização celular TLR4/NF-kB, desencadeando a produção de mediadores proinflamatórios. Nós investigamos se o sistema NF-kB está envolvido na patogênese e na progressão da doença renal diabética (DRD) experimental, em um modelo de diabetes mellitus (DM) tipo 1 de longa duração. Ratos Munich-Wistar foram tornados diabéticos por uma única injeção de estreptozotocina e foram mantidos moderadamente hiperglicêmicos por meio de injeções diárias de insulina. Após 12 meses, dois subgrupos - progressores e não-progressores - puderam ser formados com base no grau de glomeruloesclerose dos animais diabéticos. Apenas os ratos progressores exibiram ativação renal da via TLR4/NF-kB/IL-6. A ativação dessa via mostrou-se já presente em ratos com DM de curta duração (dois meses), quando a albuminúria e a glomeruloesclerose ainda não são detectáveis. O tratamento crônico com um inibidor do NF-kB, o ditiocarbamato de pirrolidina (PDTC), inibiu a ativação renal da via TLR4/NF-kB/IL-6 nos animais diabéticos, sem interferir em seus níveis glicêmicos. O PDTC preveniu o aumento progressivo da albuminúria, o desenvolvimento de lesões glomerulares/inflamação e o estresse oxidativo renal. A proteína p65, um componente do sistema NF-kB, foi detectada em glomérulos escleróticos e em áreas intersticiais inflamadas de biópsias de pacientes com nefropatia por diabetes tipo 1. Essas observações sugerem que o sistema NF-kB renal desempenha um papel chave no desenvolvimento e na progressão da DRD experimental e pode se tornar um importante alvo terapêutico no esforço para prevenir a progressão da DRD humana / High glucose concentration can activate the TLR4/NF-kB axis, triggering the production of proinflammatory mediators. We investigated whether the NF-kB pathway is involved in the pathogenesis and progression of experimental diabetic kidney disease (DKD) in a model of long-term type 1 diabetes mellitus (DM). Munich-Wistar rats underwent DM by a single streptozotocin injection, and were kept moderately hyperglycemic by daily insulin injections. After 12 months, two subgroups - progressors and nonprogressors - could be formed based on the degree of glomerulosclerosis. Only the progressors exhibited renal TLR4/NF-kB/IL-6 activation. This scenario was already present in rats with short-term DM (two months), at a time when no albuminuria or overt glomerulosclerosis can be detected. Chronic treatment with the NF-kB inhibitor, pyrrolidine dithiocarbamate (PDTC), prevented the renal TLR4/NF-kB/IL-6 activation, while exerting no interference on blood glucose. PDTC abrogated the increase in albuminuria, prevented the development of glomerular injury/inflammation and oxidative stress in DM rats. In addition, the NF-kB p65 component was detected in sclerotic glomeruli and inflamed interstitial areas in biopsy material from patients with type 1 DM. These observations indicate that the renal NF-kB pathway plays a key role in the development and progression of experimental DKD, and can become an important therapeutic target in the quest to prevent the progression of human DKD
15

Efeito da farinha da batata yacon (Smallanthus Sonchifolius) sobre o perfil glicêmico de ratos / Effect of yacon potato flour (Smallanthus sonchifolius) on blood glucose levels of rats

ROSA, Lorena Pereira de Souza 08 April 2011 (has links)
Made available in DSpace on 2014-07-29T15:23:44Z (GMT). No. of bitstreams: 1 Dissertacao Lorena Pereira de Souza Rosa.pdf: 1123488 bytes, checksum: 000fc4bd56ef5274dcff8c52cd78ed45 (MD5) Previous issue date: 2011-04-08 / The morbidity and mortality profile of the Brazilian population has changed recently in light of the increasing prevalence of chronic noncommunicable diseases. Of particular importance among these diseases is diabetes, a multiple-etiology disease characterized by insulin deficiency or decreased insulin production, or both. A major treatment goal is glycemic control, which requires medications that are expensive and have side effects. As a result, the demand for functional foods to complement this treatment is increasing. Among these foods is the yacon potato. To confirm its antidiabetic activity, glycemic profile studies in animals and humans have been carried out. The aim of this study was to evaluate the effect of yacon potato (Smallanthus sonchifolius) flour on glycemic control in nondiabetic rats and rats with streptozotocin-induced diabetes. Flour was prepared from vacon potato pulp and later a biological assay was carried out. Yacon potato flour was able to lower mean glycemia in diabetic rats, which can be explained by the FOS reserve. Animals treated with a FOS diet also had reduced blood glucose levels, confirming the ability of these fructans to control glycemia. The diabetes mellitus induction methodology proved effective, which validated the induction protocol developed. These results suggest that long-term studies with the diabetes model can best be assessed in relation to glycemic control, since there was better control starting in the third week of experiment. / Nos últimos tempos observaram-se mudanças no perfil de morbimortalidade da população brasileira, em função do aumento de prevalência das doenças crônicas não transmissíveis. Pode-se destacar entre elas o diabetes que é uma doença de etiologia múltipla que se caracteriza pela deficiência de produção de insulina, diminuição dessa produção ou ambas as condições. Um dos principais objetivos do tratamento é o controle glicemico, e para esse controle utiliza-se medicamentos que são caros e apresentam efeitos colaterais e por isso aumenta cada vez mais a busca de alimentos funcionais capazes de complementar esse tratamento. Entre esses alimentos destaca-se a batata yacon. Na busca da confirmação da atividade antidiabetica desse tubérculo, estudos são desenvolvidos com animais e humanos com avaliação do perfil glicemico. O objetivo deste trabalho foi avaliar o efeito da farinha da batata yacon (Smallanthus sonchifolius) no perfil glicêmico de ratos não diabéticos e diabéticos induzidos por streptozotocina. Elaborou-se uma farinha com a polpa da batata yacon e posteriormente foi realizado um ensaio biológico. A farinha da batata yacon foi capaz de diminuir a média da glicemia dos ratos diabéticos, o que pode ser justificado pela reserva de FOS. Os animais tratados com dieta FOS também reduziram a glicemia confirmando a capacidade de controle glicêmico desses frutanos. Foi possível observar a eficácia da metodologia de indução do diabetes melitus, validando o protocolo de indução elaborado. Tais resultados sugerem que estudos crônicos com o modelo de diabetes podem ser melhor avaliados em relação ao controle glicêmico, já que observou-se um melhor controle a partir da terceira semana de experimento.
16

New Diagnostic and Therapeutic Approaches in Adrenocortical Cancer / Ny Diagnostik och Behandling av Patienter med Binjurebarkscancer

Khan, Tanweera S January 2004 (has links)
<p>Adrenocortical cancer (ACC) is a rare disease that is often difficult to diagnose, and therefore often presents at an advanced stage. Various cytotoxic treatments have been tried with little success. Evaluation of new diagnostic methods and improvement of medical therapies are therefore crucial.</p><p>The diagnostic potential of 11C-metomidate positron emission tomography (PET) was evaluated in eleven ACC patients. PET visualized all viable tumors with high tracer uptake, including two lesions that CT failed to detect. Necrotic or fibrotic tumors were PET negative. Medication with adrenal steroid inhibitors and chemotherapy may decrease the tracer uptake.</p><p>We performed a phase-II study with streptozocin and o,p’-DDD (SO) combination therapy in 40 ACC patients. The SO therapy was found to have impact on the disease-free interval (P = 0.02) as well as on survival (P = 0.01) in patients who received adjuvant therapy after curative resection. Complete or partial response was obtained in 36.4% of patients with measurable disease.</p><p>The efficacy and tolerability of combination therapy with vincristine, cisplatin, teniposide, and cyclophosphamide (OPEC) were evaluated in eleven patients with advanced ACC after failure of SO therapy. The median survival was 21 months from the start of treatment. A partial response was achieved in two patients. Adverse events were mainly restricted to grade 1-2 toxicities, and grade 3 toxicities were observed in only two cycles.</p><p>We tested 21 ACC tumors to analyze the expression of receptor tyrosine kinases and 15 ACC for mutation analysis of c-Kit exon 11, which can be targeted by antagonists such as imatinib. All ACCs expressed one or more kinases: c-Kit in 19 ACC and phospho-c-Kit in three while 14 ACCs expressed PDGFR-beta, suggesting the potential usefulness of tyrosine kinase inhibitors. No c-Kit mutations were detected in exon 11. Further evaluation of other mutations targeted by this drug may be needed.</p>
17

New Diagnostic and Therapeutic Approaches in Adrenocortical Cancer / Ny Diagnostik och Behandling av Patienter med Binjurebarkscancer

Khan, Tanweera S January 2004 (has links)
Adrenocortical cancer (ACC) is a rare disease that is often difficult to diagnose, and therefore often presents at an advanced stage. Various cytotoxic treatments have been tried with little success. Evaluation of new diagnostic methods and improvement of medical therapies are therefore crucial. The diagnostic potential of 11C-metomidate positron emission tomography (PET) was evaluated in eleven ACC patients. PET visualized all viable tumors with high tracer uptake, including two lesions that CT failed to detect. Necrotic or fibrotic tumors were PET negative. Medication with adrenal steroid inhibitors and chemotherapy may decrease the tracer uptake. We performed a phase-II study with streptozocin and o,p’-DDD (SO) combination therapy in 40 ACC patients. The SO therapy was found to have impact on the disease-free interval (P = 0.02) as well as on survival (P = 0.01) in patients who received adjuvant therapy after curative resection. Complete or partial response was obtained in 36.4% of patients with measurable disease. The efficacy and tolerability of combination therapy with vincristine, cisplatin, teniposide, and cyclophosphamide (OPEC) were evaluated in eleven patients with advanced ACC after failure of SO therapy. The median survival was 21 months from the start of treatment. A partial response was achieved in two patients. Adverse events were mainly restricted to grade 1-2 toxicities, and grade 3 toxicities were observed in only two cycles. We tested 21 ACC tumors to analyze the expression of receptor tyrosine kinases and 15 ACC for mutation analysis of c-Kit exon 11, which can be targeted by antagonists such as imatinib. All ACCs expressed one or more kinases: c-Kit in 19 ACC and phospho-c-Kit in three while 14 ACCs expressed PDGFR-beta, suggesting the potential usefulness of tyrosine kinase inhibitors. No c-Kit mutations were detected in exon 11. Further evaluation of other mutations targeted by this drug may be needed.

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