872 resultados para diabetes typ 1
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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O diabetes mellitus do tipo 1 (T1D) é uma doença autoimune cujo tratamento é parcialmente eficaz. A terapia existente visa apenas controlar a progressão da patologia através da injeção diária de insulina exógena, portanto, uma alternativa terapêutica ou profilática para a doença é necessária. A indução do T1D por administração de estreptozotocina (STZ) em camundongos C57BL/6 é considerada um modelo bastante adequado para a investigação dessas estratégias. Além disto, vários trabalhos demonstram que o contato com antígenos ambientais pode diminuir ou impedir as manifestações clínicas do T1D e de outras doenças autoimunes. Assim, o objetivo geral desta investigação foi avaliar o efeito da infecção prévia com Strongyloides venezuelensis no desenvolvimento do T1D. Inicialmente, acompanhamos a dinâmica da infecção em camundongos C57BL/6 para a determinação da resposta imune estabelecida na fase de recuperação da infecção, e posteriormente, avaliamos o efeito da infecção no T1D. Durante a fase de recuperação, caracterizada pelo desaparecimento de ovos nas fezes, ocorreu uma resposta imune de padrão misto (Th1/Th2) com predomínio de Th2, caracterizado pela presença de IgG1 e produção significativa de IL-4, IL-5 e IL-10. Este padrão de resposta determinou um efeito protetor discreto no desenvolvimento do T1D, caracterizado por diminuição do percentual de ilhotas com inflamação mais acentuada. Estes resultados mostram, portanto, que a infecção prévia com S. venezuelensis não impediu, de forma significativa, o desenvolvimento de insulite em modelo experimental de diabetes induzido por STZ
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Alveolar bone resorption results from the inflammatory response to periodontal pathogens. Systemic diseases that affect the host response, such as type 1 diabetes mellitus (DM1), can potentiate the severity of periodontal disease (PD) and accelerate bone resorption. However, the biological mechanisms by which DM1 modulates PD are not fully understood. The aim of this study was to determine the influence of DM1 on alveolar bone resorption and to evaluate the role of receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin (OPG) in osteoclastogenesis in rats. PD was induced by means of ligature in nondiabetic and in streptozotocyn-induced DM1 rats. Morphological and morphometric analyses, stereology and osteoclast counting were performed. RANKL and OPG mRNA levels, protein content, and location were determined. PD caused alveolar bone resorption, increased the number of osteoclasts in the alveolar bone crest and also promoted changes in RANKL/OPG mRNA expression. DM1 alone showed alveolar bone destruction and an increased number of osteoclasts at the periapical and furcal regions. DM1 exacerbated these characteristics, with a greater impact on bone structure, resulting in a low OPG content and a higher RANKL/OPG ratio, which correlated with prominent osteoclastogenesis. This work demonstrates that the effects of PD and DM1 enhance bone destruction, confirms the importance of the RANKL signaling pathway in bone destruction in DM1 in animal models and suggests the existence of alternative mechanisms potentiating bone degradation in PD.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Fisiopatologia em Clínica Médica - FMB
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Objective: To determine the prevalence of patients with type 1 diabetes mellitus who meet the glycemic and cardiovascular (CV) risk factors goals and the frequency of screening for diabetic complications in Brazil according to the American Diabetes Association guidelines. Research design and methods: This was a cross-sectional, multicenter study conducted between December 2008 and December 2010 in 28 public clinics in 20 Brazilian cities. Data were obtained from 1774 adult patients (56.8% females, 57.2% Caucasians) aged 30.3 +/- 9.8 years with diabetes duration of 14.3 +/- 8.8 years. Results: Systolic blood pressure was at goal in 40.3% and diastolic blood pressure was at goal in 26.6% of hypertensive patients. LDL cholesterol and HbA1c were at the goal in 45.2% and 13.2% of the patients, respectively. Overweight was presented in 25.6% and obesity in 6.9%. Among those with more than 5 years of disease, screening for retinopathy was performed in the preceding year in 70.1%. Nephropathy and feet complications were screened in 63.1% and 65.1%, respectively. Conclusions: The majority of patients did not meet metabolic control goals and a substantial proportion was not screened for diabetic complications. These issues may increase the risk of chronic complications and negatively impact public health. (C) 2012 Elsevier Ireland Ltd. All rights reserved.
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Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by T cell-mediated destruction of pancreatic beta cells, resulting in insulin deficiency and hyperglycaemia. Recent studies have described that apoptosis impairment during central and peripheral tolerance is involved in T1D pathogenesis. In this study, the apoptosis-related gene expression in T1D patients was evaluated before and after treatment with high-dose immunosuppression followed by autologous haematopoietic stem cell transplantation (HDI-AHSCT). We also correlated gene expression results with clinical response to HDI-AHSCT. We observed a decreased expression of bad, bax and fasL pro-apoptotic genes and an increased expression of a1, bcl-xL and cIAP-2 anti-apoptotic genes in patients' peripheral blood mononuclear cells (PBMCs) compared to controls. After HDI-AHSCT, we found an up-regulation of fas and fasL and a down-regulation of anti-apoptotic bcl-xL genes expression in post-HDI-AHSCT periods compared to pre-transplantation. Additionally, the levels of bad, bax, bok, fasL, bcl-xL and cIAP-1 genes expression were found similar to controls 2 years after HDI-AHSCT. Furthermore, over-expression of pro-apoptotic noxa at 540 days post-HDI-AHSCT correlated positively with insulin-free patients and conversely with glutamic acid decarboxylase autoantibodies (GAD65) autoantibody levels. Taken together, the results suggest that apoptosis-related genes deregulation in patients' PBMCs might be involved in breakdown of immune tolerance and consequently contribute to T1D pathogenesis. Furthermore, HDI-AHSCT modulated the expression of some apoptotic genes towards the levels similar to controls. Possibly, the expression of these apoptotic molecules could be applied as biomarkers of clinical remission of T1D patients treated with HDI-AHSCT therapy.
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Objective: To study the activation of an inflammatory cascade through leukocyte mRNA expression of TLR2, TLR4, MyD88, and pro-inflammatory cytokines in individuals with childhood onset type 1 diabetes. Design and methods: Seventy-six type 1 diabetic patients and 100 normoglycemic subjects (NG) 6 to 20 years old were recruited. Type 1 diabetic patients (DM1) were considered to have good (DM1G) or poor (DM1P) glycemic control according to the values of glycated hemoglobin. TLR2, TLR4, MyD88, interleukin-1 beta (IL-1 beta), IL-6, and tumor necrosis factor alpha (TNF-alpha) mRNA expressions were measured in peripheral blood leukocytes (PBL) by real-time polymerase chain reaction (PCR). Urea, creatinine, albumin, and total protein serum levels were determined. Urinary albumin-to-creatinine ratio (ACR) was calculated. Results: DM1 and DM1P patients showed higher glycated hemoglobin (10 and 11%, respectively) and serum glucose concentrations (208 and 226 mg/ dL, respectively) compared to NG (Glycated hemoglobin: 7% and glucose: 76 mg/ dL) (p < 0.05). PBL mRNA expressions of TLR2, MyD88, IL-1 beta, IL-6, and TNF-alpha were higher in DM1 and TLR2, IL-1 beta, and IL-6 expressions were higher in DMP1 compared to NG (p < 0.05). In DM1, serum albumin and total protein were lower, while serum urea and ACR were higher in comparison to NG (p < 0.05). However, these differences compared to NG were more pronounced in DM1P, which included nine individuals with microalbuminuria. Conclusions: Increased mRNA expression of TLR2, MyD88, and pro-inflammatory cytokines in leukocytes of patients with childhood onset type 1 diabetes indicates the development of a TLR2-mediated pro-inflammatory process, which may also be associated with an early inflammatory process in the kidney and the occurrence of microalbuminuria.
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The objective of this study was to determine the frequencies of autoantibodies to heterogeneous islet-cell cytoplasmic antigens (ICA), glutamic acid decarboxylase(65) (GAD(65)A), insulinoma-associated antigen-2 (IA-2A) and insulin (IAA)-and human leukocyte antigen (HLA) class II markers (HLA-DR and -DQ) in first degree relatives of heterogeneous Brazilian patients with type I diabetes(T1DM). A major focus of this study was to determine the influence of age, gender, proband characteristics and ancestry on the prevalence of autoantibodies and HLA-DR and -DQ alleles on disease progression and genetic predisposition to T1DM among the first-degree relatives. IAA, ICA, GAD(65)A, IA-2A and HLA- class II alleles were determined in 546 first-degree-relatives, 244 siblings, 55 offspring and 233 parents of 178 Brazilian patients with T1DM. Overall, 8.9% of the relatives were positive for one or more autoantibodies. IAA was the only antibody detected in parents. GAD(65) was the most prevalent antibody in offspring and siblings as compared to parents and it was the sole antibody detected in offspring. Five siblings were positive for the IA-2 antibody. A significant number (62.1%) of siblings had 1 or 2 high risk HLA haplotypes. During a 4-year follow-up study, 5 siblings (expressing HLA-DR3 or -DR4 alleles) and 1 offspring positive for GAD(65)A progressed to diabetes. The data indicated that the GAD(65) and IA-2 antibodies were the strongest predictors of T1DM in our study population. The high risk HLA haplotypes alone were not predictive of progression to overt diabetes.
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Background: The purpose of this study was to evaluate the effect of the duodenal-jejunal bypass liner (DJBL), a 60-cm, impermeable fluoropolymer liner anchored in the duodenum to create a duodenal-jejunal bypass, on metabolic parameters in obese subjects with type 2 diabetes. Methods: Twenty-two subjects (mean age, 46.2 +/- 10.5 years) with type 2 diabetes and a body mass index between 40 and 60 kg/m(2) (mean body mass index, 44.8 +/- 7.4 kg/m(2)) were enrolled in this 52-week, prospective, open-label clinical trial. Endoscopic device implantation was performed with the patient under general anesthesia, and the subjects were examined periodically during the next 52 weeks. Primary end points included changes in fasting blood glucose and insulin levels and changes in hemoglobin A1c (HbA1c). The DJBL was removed endoscopically at the end of the study. Results: Thirteen subjects completed the 52-week study, and the mean duration of the implant period for all subjects was 41.9 +/- 3.2 weeks. Reasons for early removal of the device included device migration (n = 3), gastrointestinal bleeding (n = 1), abdominal pain (n = 2), principal investigator request (n = 2), and discovery of an unrelated malignancy (n = 1). Using last observation carried forward, statistically significant reductions in fasting blood glucose (-30.3 +/- 10.2 mg/dL), fasting insulin (-7.3 +/- 2.6 mu U/mL), and HbA1c (-2.1 +/- 0.3%) were observed. At the end of the study, 16 of the 22 subjects had an HbA1c < 7% compared with only one of 22 at baseline. Upper abdominal pain (n = 11), back pain (n = 5), nausea (n = 7), and vomiting (n = 7) were the most common device-related adverse events. Conclusions: The DJBL improves glycemic status in obese subjects with diabetes and therefore represents a nonsurgical, reversible alternative to bariatric surgery.
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Objective: To evaluate the effect of vitamin D-3 on cytokine levels, regulatory T cells, and residual beta-cell function decline when cholecalciferol (vitamin D-3 administered therapeutically) is given as adjunctive therapy with insulin in new-onset type 1 diabetes mellitus (T1DM). Design and Setting: An 18-month (March 10, 2006, to October 28, 2010) randomized, double-blind, placebo-controlled trial was conducted at the Diabetes Center of Sao Paulo Federal University, Sao Paulo, Brazil. Participants: Thirty-eight patients with new-onset T1DM with fasting serum C-peptide levels greater than or equal to 0.6 ng/mL were randomly assigned to receive daily oral therapy of cholecalciferol, 2000 IU, or placebo. Main Outcome Measure: Levels of proinflammatory and anti-inflammatory cytokines, chemokines, regulatory T cells, hemoglobin A(1c), and C-peptide; body mass index; and insulin daily dose. Results: Mean (SD) chemokine ligand 2 (monocyte chemoattractant protein 1) levels were significantly higher (184.6 [101.1] vs 121.4 [55.8] pg/mL) at 12 months, as well as the increase in regulatory T-cell percentage (4.55%[1.5%] vs 3.34%[1.8%]) with cholecalciferol vs placebo. The cumulative incidence of progression to undetectable (<= 0.1 ng/mL) fasting C-peptide reached 18.7% in the cholecalciferol group and 62.5% in the placebo group; stimulated C-peptide reached 6.2% in the cholecalciferol group and 37.5% in the placebo group at 18 months. Body mass index, hemoglobin A(1c) level, and insulin requirements were similar between the 2 groups. Conclusions: Cholecalciferol used as adjunctive therapy with insulin is safe and associated with a protective immunologic effect and slow decline of residual beta-cell function in patients with new-onset T1DM. Cholecalciferol may be an interesting adjuvant in T1DM prevention trials.
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Stem cell therapy is one of the most promising treatments for the near future. It is expected that this kind of therapy can ameliorate or even reverse some diseases. With regard to type 1 diabetes, studies analyzing the therapeutic effects of stem cells in humans began in 2003 in the Hospital das Clínicas of the Faculty of Medicine of Ribeirão Preto - SP USP, Brazil, and since then other centers in different countries started to randomize patients in their clinical trials. Herein we summarize recent data about beta cell regeneration, different ways of immune intervention and what is being employed in type 1 diabetic patients with regard to stem cell repertoire to promote regeneration and/or preservation of beta cell mass.
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Abstract Background The use of stem cells to treat type 1 diabetes mellitus has been proposed for many years, both to downregulate the immune system and to provide β cell regeneration. Conclusion High dose immunosuppression followed by autologous hematopoietic stem cell transplantation is able to induce complete remission (insulin independence) in most patients with early onset type 1 diabetes mellitus.