abstract: Type 1 Diabetes Mellitus (T1DM) is a chronic disease that requires maintaining tight metabolic control through complex behavioral and pharmaceutical regimens. Subtle cognitive impairments and stress response dysregulation may partially account for problems negotiating life changes and maintaining treatment adherence among emerging adults. The current study examined whether young adults with T1DM physiologically respond to psychological stress in a dysregulated manner compared to non-diabetic peers, and if such individuals also demonstrated greater cognitive declines following psychological stress. Participants included 23 young adults with T1DM and 52 non-diabetic controls yoked to T1DM participants based on age, gender, ethnicity, participant education, and maternal education. Participants completed a laboratory-based social stressor, pre- and post-stressor neurocognitive testing, provided fingerstick blood spots (for glucose levels) and salivary samples (for cortisol levels) at five points across the protocol, and completed psychosocial questionnaires. Related measures ANOVAs were conducted to assess differences between T1DM participants and the average of yoked controls on cortisol and cognitive outcomes. Results demonstrated that differences in cortisol reactivity were dependent on T1DM participants' use of insulin pump therapy (IPT). T1DM participants not using IPT demonstrated elevated cortisol reactivity compared to matched controls. There was no difference in cortisol reactivity between the T1DM participants on IPT and matched controls. On the Stroop task, performance patterns did not differ between participants with T1DM not on IPT and matched controls. The performance of participants with T1DM on IPT slightly improved following the stressor and matched controls slightly worsened. On the Trail Making Test, the performance of participants with T1DM was not different following the stressor whereas participants without T1DM demonstrated a decline following the stressor. Participants with and without T1DM did not differ in patterns of performance on the Rey Verbal Learning Task, Sustained Attention Allocation Task, Controlled Oral Word Association Task, or overall cortisol output across participation. The results of this study are suggestive of an exaggerated cortisol response to psychological stress in T1DM and indicate potential direct and indirect protective influences of IPT. / Dissertation/Thesis / Ph.D. Psychology 2013

O Diabetes Mellitus tipo 1 (DM1) está associado a uma incidência aumentada de doença micro e macrovascular. Estudos sugerem que a doença vascular no DM1 tenha como evento precursor a disfunção endotelial (DE). A hiperglicemia parece causar DE no DM1 através da geração do estresse oxidativo. O momento exato do surgimento da DE na história natural do DM1, assim como a influência do controle glicêmico de curto e longo prazo ainda não estão estabelecidos. Objetivo: O objetivo principal do presente estudo foi avaliar a função endotelial através da Dilatação Arterial Mediada por Fluxo (DMF) em indivíduos com Diabetes Mellitus tipo1. Os objetivos secundários foram analisar os fatores que possam estar envolvidos com a disfunção endotelial no DM1, como o tempo de diabetes, o controle glicêmico e a presença de complicações microvasculares, como a microalbuminúria. Métodos: Estudo prospectivo transversal com 57 pacientes com DM1 e 10 indivíduos não diabéticos, consecutivamente alocados e comparados quanto à presença de DE, através da DMF, aferida pela dilatação da artéria braquial após hiperemia reativa (dilatação endotélio-dependente) e após dilatação mediada por uso de nitrato sublingual (dilatação endotélio-independente). Considerou-se como DE quando valores de DMF foram menores ou iguais a 8% em relação ao valor basal. Os pacientes foram orientados a fazer monitorização glicêmica capilar intensiva nos 30 dias que antecederam a avaliação vascular. No 30º dia, houve coleta de exames laboratoriais e a avaliação vascular foi realizada. Dados prospectivos e históricos de hemoglobina glicosilada (HbA1c), através da técnica de imunoturbidimetria (Cobas Integra 400; Roche), foram obtidos aos 3, 6, 9,12,15,18 e 24 meses anteriores ao teste para DMF. Os critérios de exclusão foram: tabagismo, hipertensão, obesidade, hipotireoidismo, uso de estatina, gestação, história de neoplasia ou doença vascular. Resultados: Em 57 pacientes com DM1 estudados, 28 (49%) apresentaram DE. A média da dilatação endotélio-dependente foi significativamente menor nos pacientes com DM1, comparados aos indivíduos não-diabéticos (9,48±6,48% vs.14,56±5,60%, p=0,02). A dilatação endotélio-independente foi significativamente menor nos pacientes com DM1 em relação aos controles (22,26±9,2% vs. 29,31±4,2%, p=0,02, VR: acima de 8%), mas não houve diferença entre os DM1 com ou sem DE (p= 0,72). O tempo de DM1 (meses) foi maior nos pacientes com DE do que nos sem DE (105,4±74,7 vs. 66,3±48,0, p=0.02) e houve correlação linear negativa entre duração do DM e presença de DE (r-0,28, p=0,02). A média da HbA1c (%) coletada no momento da avaliação vascular foi semelhante entre pacientes com DM1 com DE e sem DE (8,97%±1.85 vs 8,23%±1.45, p=0.10) e não houve correlação significativa com a DMF (r=-0,128 p=0,34). Todavia, quando as HbA1c históricas foram avaliadas, houve correlação significativa com a HbA1c aos 15 meses (r=-0,303, p=0,02) e no período de 12-24 meses anteriores ao exame vascular (r=-0,289, p=0,03), mas não com a HbA1c média de 0-12m (r=-0,181 p=0,18). A DMF foi menor nos pacientes com microalbuminúria em relação aos normoalbuminúrcos (4,83±3,81% vs 10,35±6,50%, p=0,015). A microalbuminúria também foi mais prevalente nos DM1 com DE do que sem DE (22,2% vs 3,5%, p=0,04). Considerando apenas os pacientes com DM1 com tempo de DM menor que 5 anos, 10/28 (35,7%) apresentaram DE. Com relação a dilatação não-dependente de endotélio (%), não houve diferença em relação aos controles (p=0,16) e nem entre os DM1 com e sem DE (p=0,27). A média da HbA1c na época do exame vascular também não foi diferente nos pacientes com e sem DE (8,20±0,94% vs. 7,99±1,37%, p=0,66). As correlações de Pearson entre a DMF e as HbA1c históricas foram negativas aos 12 meses (r=-0,419, p=0,03), aos 15 meses (r=-0,437, p=0,03) e com a HbA1c média de12-24 meses (r=-0,426, p=0,027). Conclusões: Pacientes com DM1 apresentam prejuízo na função endotelial, quando comparados a controles não diabéticos. A DE é um evento precoce na história natural do DM1, e está presente nos pacientes antes dos 5 anos de doença, estando associada, ao tempo de DM1, à presença de microalbuminúria e ao controle metabólico de longo-prazo. A ausência de disfunção de músculo liso endotelial no grupo com menos de 5 anos de DM, com valores de dilatação não-endotéliodependente semelhantes aos controles, sugere ser a DE um fenômeno ainda reversível nos primeiros anos de doença. / Patients with Type 1 diabetes (T1DM) are at high-risk for developing micro and macrovascular complications. Endothelial dysfunction (ED) has been suggested to be a precursor of both complications in Type 1 diabetes. Hyperglycemia may be associated to ED through generation of oxidative stress. The exactly moment when ED occurs in T1DM is until not well established. Also we do not known if long-term rather than short term metabolic control have a greater impact in ED. Objective: The aim of this study was to assess endothelial function by Flow Mediated Dilation (FMD) in (T1DM) patients and compare with non- diabetic controls. Secondary objectives were to analyze factors that could be associated to ED: duration of T1DM, glycemic control and microvascular complications like microalbuminuria. Research design and methods: In a cross-sectional study 57 adolescents with T1DM and 10 non-diabetic controls, were recruited and compared for the presence of ED by FMD with evaluation of reactive hyperemia (endothelium-dependent dilatation) and after using sublingual nitrate spray for assessed non-endothelialdependent dilatation. ED was considered when FMD ≤ 8% in relation to basal value. Patients performed intensive self monitoring blood glucose for 30 days before vascular studies. At day 30, blood was drawn for biochemical determinations and endothelial function was carried out. Historical data from Glycated hemoglobin (HbA1c), determined by immunoturbidimetry (Cobas Integra 400; Roche) were collected at 3, 6, 9,12,15,18 and 24 months before the test for FMD. Excluding criteria were any time tobacco use, clinical hypertension, obesity, hypothyroidism, statin use, current pregnancy and any history of previous neoplasia or vascular disease. Results: Of 57 T1DM patients studied, 28 (49%) presented ED. FMD was significantly decreased in T1DM compared to controls (9.48±6.48% vs. 14.56±5.60%, p=0.02). Nitrate-mediated dilation (%) was decreased in T1DM compared to controls (22.26±9.2% vs. 29.31±4.2%, p=0.02, RV= >8%), but it was not different between T1DM with or without ED (p=0.72). The duration of T1DM was longer in ED vs. Non- ED patients: 105.4±74.7 vs. 66.3±48.0 months, p= 0.02 and presented negative linear correlation between duration of T1DM and FMD (r=-0.284, p=0.03). HbA1c at the moment of the vascular analysis did not differ between ED and Non-ED patients (8.97±1.85% vs. 8.23±1.44%, p= 0.10) and it was not associated with FMD (r=-0.128, p=0.34). However, we found significant negative correlation between HbA1c and FMD at 15 months (r=-0.303, p=0.02) and at 12-24 months before vascular study, but not with median HbA1c of 0-12m (r=-0.181 p=0.8). Microalbuminuria was more prevalent in T1DM patients with ED than Non-ED (22.2% vs. 3.5%, p=0.04). FMD was decreased in microalbuminuric compared to normoalbuminuric patients (4.83±3.81% vs 10.35±6.50%, p=0.015). In T1DM patients with less than 5 years of disease, 10 of 28 (35.7%) presented ED. Nitrate-mediated dilation, in this group, was not decreased compared to controls (p=0.16) and it was not different in T1DM patients with or without ED (p=0.27). HbA1c at the moment of vascular analysis did not significantly differ in ED compared to Non-ED patients (8.20±0.94% vs.7.99±1.37%, p=0.66). Pearson’s correlation between FMD and historical HbA1c was negative with HbA1c at 12 (r=-0.419, p=0.03), at 15 (r=-0.437, p=0.03) and 12-24 months before vascular analysis (r=- 0.426, p=0.02). Conclusions: Endothelial function is impaired in T1DM patients compared to nondiabetic controls. ED is a phenomenon that can occur quite early in the natural history of T1DM, presented before 5 years of disease and is related to duration of disease, long- term metabolic control and microalbuminúria. Vascular smooth muscle was not impaired in T1DM patients with less than 5 years of disease, with values of non-endothelial-dependent dilation similar to controls, suggesting that ED can be a reversible event in this first years of disease.

O adequado manejo do DM Tipo 1 tem se tornado um desafio, principalmente para as próprias crianças, em virtude da presença de comportamentos, habilidades e conhecimentos inadequados que colaboram para a não adesão ao tratamento e para aumento de complicações em longo prazo. Estudos têm demonstrado que compreender as experiências de vida das crianças nos seus diversos espaços, valorizando-as e buscando maior aproximação com as mesmas, pode contribuir para a partilha do conhecimento sobre o manejo do diabetes e para o maior envolvimento da criança no cuidado. O objetivo deste trabalho foi compreender, na perspectiva de crianças com DM Tipo 1, os fatores que interferem no manejo da doença. Trata-se de uma pesquisa qualitativa, de natureza exploratória. Participaram do estudo 19 crianças. Utilizamos a entrevista semiestruturada e, como recurso facilitador da comunicação com a criança, os fantoches. Esses brinquedos foram confeccionados pelas próprias crianças e criou-se, também, um cenário que ilustrou e complementou a utilização dos fantoches no dia da entrevista. A análise dos dados empíricos foi feita por meio da análise de conteúdo. Os resultados evidenciaram a compreensão do que é ser criança com diabetes e dos fatores relacionados à sua existência, como seus sentimentos e percepções. A compreensão da interação da criança com os conhecimentos que possui sobre a sua doença, sua inserção no processo do autocuidado, as habilidades desenvolvidas e os recursos disponíveis para lidar com as demandas da doença constituem fatores que interferem de forma positiva ou negativa no manejo da doença e merecem ser foco de atenção dos profissionais de saúde. Todos esses elementos atuam dinamicamente nos espaços do cotidiano da criança, tais como o familiar, o escolar, o de amizades, o de lazer e o dos serviços de saúde, atuando como fatores que fragilizam ou potencializam o manejo da doença. O apoio de familiares, amigos, professores e profissionais de saúde que compartilham as experiências de ser uma criança com diabetes mostrou-se essencial para o alcance do adequado manejo. Além disso, o conhecimento adquirido por estes atores e pela própria criança interfere diretamente no manejo do DM Tipo 1. Os resultados deste estudo evidenciam ações que visam a fortalecer o trabalho da equipe multidisciplinar no cuidado da criança com diabetes e apontam cenários de atuação que podem ser incrementados pelos profissionais de saúde. O enfermeiro ocupa posição privilegiada para identificar e operacionalizar ações apropriadas ao estágio de desenvolvimento da criança e às suas necessidades, em todos os espaços em que vive, atuando, assim, em consonância com todos os envolvidos em prol do sucesso do manejo da doença. / The adequate handling of Type 1 DM has become a challenge, mainly for the children themselves, due to the presence of inadequate behaviors, skills and knowledge that contribute to non-adherence to treatment and increased complications in the long term. Research has demonstrated that understanding children\'s life experiences in their different spaces, valuing them and seeking greater approximation, can contribute to knowledge sharing on diabetes management and to the children\'s greater involvement in care. This research aimed to understand, from the perspective of children with Type 1 DM, the factors that interfere in the management of this disease. This is a qualitative and exploratory research. Study participants were 19 children. Semi-structured interviews were used and, to facilitate communication with the child, puppets, which the children made themselves. A scenario was also created to illustrate and complement the use of puppets on the day of the interview. Content analysis was used for empirical data analysis. Results evidenced the understanding of what it means to be a child with diabetes and the factors related to his/her existence, such as feelings and perceptions. Understanding of these children\'s interaction with their knowledge about their disease, their insertion in the self-care process, developed skills and resources available to deal with the demands of the disease constitute factors that interfere positively or negatively in disease management and deserve further attention from health professionals. All of these elements act dynamically in the child\'s daily spaces, such as the family, school, friendships, leisure and health services, as factors that weaken or strengthen disease management. Support from relatives, friends, teachers and health professionals who share the experiences of being a child with diabetes showed to be essential to achieve adequate management. Moreover, the knowledge these actors and the children themselves acquire interferes directly in Type 1 DM management. These study results evidence actions aimed at strengthening the work of the multidisciplinary team in care delivery to children with diabetes and indicate activity scenarios which health professionals can build upon. Nurses play a privileged role to identify and put in practice actions that are appropriate for the children\'s development stage and needs, in all spaces they live in. Thus, they act in line with all parties involved with a view to successful disease management.

Introdução: Diabetes tipo 1A(DM1A) é uma doença causada pela destruição autoimune das células beta. Em adição aos linfócitos T helper 1(Th1) e Th2, um subtipo específico de células T helper recentemente descrito, Th17, caracterizado pela produção da interleucina 17(IL-17A), IL-17F e IL-22, está também envolvido na imunidade adaptativa e autoimunidade, incluindo DM1A. A IL-23 tem função fundamental na expansão e sobrevivência das células Th17. A mesma é composta por 2 subunidades: a p19-específica (IL-23A) e a p40. Variantes dos genes IL-23A e de seu receptor (IL-23R) ou o aumento das concentrações séricas da IL-23 estão associados a várias doenças autoimunes, mas seus efeitos no DM1A não estão definidos. Com o intuito de avaliar a importância da IL-23 na patogênese do DM1A, as variantes dos genes IL23A e IL23R foram analisadas. Metodologia: A região codificadora e os regiões intrônicas proximais do gene IL23A, incluindo a região 5 proximal foram sequenciadas. Duas variantes do gene IL23A (rs2066808 e rs11171806) e duas do gene IL-23R (rs11209026 e rs10889677) foram também genotipadas. A amostra contou com 370 pacientes com DM1A e 314 indivíduos controles saudáveis. As medidas das concentrações séricas da IL-23 e os autoanticorpos pancreáticos e extra-pancreáticos foram determinados. Resultados: Nós observamos somente uma das seis variantes da IL-23 descritas nos bancos de dados (rs11171806 G>A localizada no exon 3) e descrevemos uma nova variante no gene IL-23A, que consistiu na substituição da citosina por timina na posição c.-403 (C>T) na região 5 proximal deste gene (encontrada em heterozigose em apenas uma paciente com DM1A, do sexo feminino, com 28 anos ao diagnóstico).Os alelos G dessas duas variantes estiveram em forte desequilíbrio de ligação (D\' = -0,825 para controles, p<2,0X10-6 e D\' = -0,902, p<2,0X10-17 para pacientes). Em consequência, a análise dos haplótipos destas variantes foi realizada. O haplótipo GG foi mais frequente nos controles (16.7%) do que nos pacientes com DM1A (9.5%), conferindo proteção à doença (pc = 0,0009, OR = 0,53) . A presença do haplótipo GG diferiu de acordo com a etnia no conjunto de pacientes e controles, sendo menor naqueles de etnia caucasóide (18%) em relação aos outros grupos (39%); p<0.0001. Entretanto, o efeito protetor da haplótipo GG foi independente da etnia. As duas variantes do gene IL23R (rs10889677 e rs11209026) tinham frequência alélica e genotípica semelhante entre pacientes com DM1A e controles. Não foi observada diferença significante nas concentrações da IL-23 entre 135 pacientes com DM1A (5,65 ± 14,0 pg/mL) e 112 indivíduos controles (9,06 ± 23,7pg/mL) (p =0,18). , mesmo quando analisamos apenas o pacientes com duração do diabetes inferior a dois anos, nos quais a resposta imune contra as células beta ainda está presente, (4.65 ± 6.94 pg/mL e 9.07 ± 23.62 pg/mL, p = 0.076). Não foi encontrada associação entre as variantes do gene IL23A com a idade diagnóstica, presença do peptídeo C residual e auto-anticorpo anti-descarboxilase do ácido glutâmico em pacientes com diagnóstico recente de DM1A. Estas variantes também não influenciaram na freqüência dos auto anticorpos extrapancreáticos: anti-tireoglobulina, anti-peroxidase, anti-21 hidroxilase, fator anti-núcleo, fator reumatóide e anti-citoplasma de neutrófilos. Conclusões: O haplótipo GG das variantes do gene lL23A (rs11171806 e rs2066808) foi associado a proteção ao DM1A. As variantes do gene IL23R (rs11209026 e rs10889677) não foram associadas ao DM1A. As concentrações séricas da IL-23 foram semelhantes entre os grupos. / Introduction: Type 1 diabetes mellitus (T1D) is a disorder caused by the immune-mediated destruction of insulin-secreting pancreatic beta cells. In addition to T helper 1 (Th1) and Th2 cells, a recently discovered subset of T helper cells, Th17, characterized by the production of interleukin 17 A (IL-17A), IL-17F, and IL-22 is also involved in adaptive immunity and autoimmunity, including T1D. The Interleukin IL-23 has a central role in the expansion and survival of Th 17 cells. It is composed of two subunits: p19-specific (IL-23A) and p40. Single nucleotide polymorphisms (SNPs) of IL-23A and IL-23 receptor (IL-23R) genes or increased IL-23 serum concentrations were associated with several autoimmune diseases, but their role in T1D has not been defined. We therefore searched for variants of IL-23A and IL-23R genes that could predispose to T1D. Methods:The coding regions and boundary intron sequences of IL-23A gene, including the 5 proximal region were sequenced. Two variants (rs2066808 and rs 11171806) of IL-23A and two of IL-23R (rs11209026 and rs10889677) genes were also genotyped. IL-23 serum levels and pancreatic and extra-pancreatic auto-antibodies were also determined. The cohort involved 370 patients with T1D and 314 healthy control subjects.Results: We observed only 1 out of 6 IL-23A coding variants (rs11171806 G>A localized in exon 3) described in a database repository . A new allelic variant of the IL-23A gene, consisting of the substitution of a cytosine by a thymine at position c.-403 (C>T) in the 5 proximal region of the IL-23A gene (found in heterozygosis in only 1 female patient with T1D) was described. The G alleles of rs11171806 and rs2066808 variants of IL-23A gene were in strong linkage disequilibrium (D\' = -0,825 for controls, p<2,0X10-6 and D\' = -0,902, p<2,0X10-17 for patients). So, further analyses were performed with the haplotypes instead of separated SNPs. The GG haplotype was more frequent in controls (16,7%) than in T1D patients (9,5%), conferring a protection to the disease (pc= 0,0009, OR = 0.53). The presence of haplotype GG was also different according to the ethnic group in the overall sample (patients+controls), when we pooled the Caucasians (18%) against the other groups (39%); p<0.0001. However, the lower susceptibility to T1D conferred by GG haplotype was independent of the ethnic group. Two IL-23R gene variants (rs10889677 and rs11209026) were also analyzed. The allelic and genotypic frequency of the variants did not differ between patients with T1D and control subjects. No significant differences were observed between the plasma IL-23 concentrations of 135 T1D patients (5.65 ± 14.0) and 112 control subjects (9.06 ± 23.7) (p = 0.18), even when we only the patients with less than 2 years disease duration (n = 43), when the immune attack to beta cells is still present, were included (4.65 ± 6.94 pg/mL and 9.07 ± 23.62 pg/mL, p = 0.076). No association was found between IL-23A variants with age at diagnosis of diabetes, presence of residual C-peptide levels or frequency of glutamic acid anti-decarboxilase antibody in patients with recent-onset T1D. Furthermore, these variants were not related to the presence of the extrapancreatic autoantibodies such as thyroid peroxidase (TPO) Ab, thyroglobulin (TG) Ab, 21-Hydroxilase (21OH) Ab, Anti nuclear factor (ANA) Ab, rheumatoid factor (FR) Ab and Neutrophil cytoplasmic (ANCA) Ab. Conclusions : The GG haplotype of lL23A gene variants( rs11171806 and rs2066808) was protective against T1D. The IL23R variants (rs11209026 and rs10889677) were not associated with susceptibility toT1D . IL-23 serum concentrations did not differ between T1D patients and controls.

Submitted by Neusa Fagundes (neusa.fagundes@unioeste.br) on 2018-07-12T13:40:55Z No. of bitstreams: 2 Gabriela_Bronczek2018.pdf: 2363715 bytes, checksum: 1e18d95b6ab4cde85b4747bc5aac855a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-07-12T13:40:55Z (GMT). No. of bitstreams: 2 Gabriela_Bronczek2018.pdf: 2363715 bytes, checksum: 1e18d95b6ab4cde85b4747bc5aac855a (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Appropriate control of glycaemia in type 1 diabetic patients (T1D) needs daily insulin administration, which can lead to hypoglycemic events and others side effects. Therefore, it is important to find endogenous molecules, without side effects, for T1D treatment. In this sense, the biliary acid conjugated with taurine, tauroursodeoxycholic acid (TUDCA) presents positive effects in type 2 diabetes treatment. However, its beneficial effects on T1D have been less explored. Thus, we have assessed the effects of TUDCA on glycemic control in streptozotocin-induced diabetic mice. For this, C57BL/6 mice received intraperitoneal (i.p.) administration of streptozotocin (40mg/kg, streptozotocin was dissolved in 0,5 M citrate buffer, pH 4,5) for 5 days, STZ group (n=22). Whereas control (CON) group (n=6) received the same volume of citrate buffer. Once confirmed diabetes in the STZ group, diabetic mice were randomly selected and allocated in the 2 following groups: 1) STZ group (n=10) that received i.p. PBS, and 2) STZ+TUDCA group (n=12) that received i.p. 300 mg/kg TUDCA (dissolved in PBS). These treatments were maintained for 24 days. After 15 days of treatment, STZ+TUDCA mice showed a 43% reduction in blood glucose, compared with STZ. This reduction was probably due to an increase in insulinemia. This increase in insulinemia may be explained, at least in part, by a reduction in hepatic activity of IDE (insulin degrading enzyme) the enzyme responsible for insulin degradation, as well as by an increase in beta cell mass and higher beta cell number per islet. All together, these effects contributed to the improvement of metabolic flexibility. In conclusion, TUDCA shows therapeutic potential for the control of glycemia in T1D. / Pacientes com Diabetes Mellitus do tipo 1 (DM1) necessitam de administração diária de insulina exógena, o que pode causar eventos de hipoglicemia e outros efeitos colaterais. Diante disso, é de extrema importância encontrar moléculas endógenas que possam ser utilizadas no controle glicêmico no DM1 e que não apresentem efeitos colaterais. Nesse sentido, o ácido biliar conjugado com taurina, ácido tauroursodesoxicólico (TUDCA), tem se mostrado eficaz no tratamento do Diabetes Mellitus do tipo 2; contudo, sua eficiência no tratamento do DM1 tem sido menos explorada. Assim, o objetivo deste estudo foi avaliar os efeitos do TUDCA no controle glicêmico de camundongos com DM1. Para tanto, foram utilizados camundongos C57BL/6 divididos inicialmente em dois grupos: 1) Grupo controle (CTL n=6), que recebeu injeção intraperitoneal (i.p.) de tampão citrato de sódio (0,5 M, pH 4,5) e 2) Grupo estreptozotocina (STZ n=22), o qual recebeu uma dose i.p. de 40mg/kg de STZ (dissolvida em tampão citrato de sódio 0,5 M, pH 4,5) durante cinco dias para indução do DM1. Uma vez instalado o DM1 no grupo STZ, esse foi subdividido em dois grupos: 1) STZ (n=10), que recebeu injeção i.p. de PBS e 2) STZ+TUDCA (n=12), que recebeu uma dose i.p. de 300 mg/kg de TUDCA (dissolvido em PBS). Essas administrações foram executadas diariamente durante 24 dias. Após 15 dias de tratamento, os animais do grupo STZ+TUDCA apresentaram redução de 43% na glicemia, comparado ao grupo STZ. Essa redução da glicemia, provavelmente, deveu-se a um aumento da insulinemia, observada ao final do tratamento. Esse aumento da insulinemia pode ser explicado, pelo menos em parte, pela redução da atividade hepática da IDE (insulin degrading enzyme), responsável pela degradação da insulina, bem como pelo aumento da massa de células beta e da quantidade dessas células por ilhota. Juntos, esses efeitos contribuíram para a melhora na flexibilidade metabólica nos camundongos STZ+TUDCA. Concluímos, então, que o TUDCA apresenta potencial terapêutico para o controle da glicemia no DM1.

O presente trabalho refere-se ao estudo do papel dos microRNAs no controle pós-transcricional das células T de camundongos Non Obese Diabetic (NOD) modelo que reproduz o diabetes mellitus do tipo 1 (DM-1). Durante o desenvolvimento do trabalho, procurou-se esclarecer a hipótese de que os microRNAs controlam os níveis de determinados RNAs mensageiros (mRNAs) das células T durante a indução ou perda de tolerância imunológica. Portanto, a expressão alterada dos microRNAs estaria contribuindo com o processo da autoimunidade. Sendo assim, o objetivo do estudo foi identificar os perfis de expressão e as redes de interação entre um conjunto de microRNAs e seus respectivos mRNAs alvos nos timócitos e nos linfócitos T CD3+ periféricos durante o desenvolvimento do diabetes mellitus do tipo 1 (DM-1) em camundongos NOD. Para avaliar a expressão de genes codificadores de mRNAs, sendo estes possíveis alvos de microRNAs, utilizou-se a tecnologia de microarrays. O uso de programas de análise e para a construção das redes foi imprescindível. Acreditase que fenômenos complexos como a regulação pós-transcricional de células T e seu envolvimento no processo de tolerância imunológica, bem como o surgimento de doenças autoimunes, podem ser melhor compreendidos por meio da genômica funcional. Os resultados encontrados evidenciam uma expressão diferenciada de mRNAs e microRNAs em timócitos e linfócitos T CD3+ periféricos durante o desenvolvimento do diabetes mellitus do tipo 1 (DM-1). As diferenças nos perfis transcricionais encontradas envolvem expressão de genes (mRNAs) relacionados diretamente ao sistema imune, a diferenciação e ativação de linfócitos T e a apoptose, bem como a outros processos relacionados a resposta imune. Além disso, as redes de interação microRNA-mRNA encontradas no presente trabalho evidenciam interações já conhecidas e apresentam novas interações, mostrando a participação de um grupo de microRNAs que estão atuando no controle pós-transcricional do diabetes do tipo 1 em camundongos NOD, contribuindo com a melhor compreensão do controle genético-molecular das doenças autoimunes, principalmente do diabetes do tipo 1. / This study refers to the role played by microRNAs in the post-transcriptional control of T cells from non obese diabetic (NOD) mice model which reproduces the type 1 diabetes (T1D). During the study, it was tried to clarify the hypothesis that microRNAs control certain messenger RNAs (mRNAs) levels of the T cells during the induction or loss of immunological tolerance. Therefore, the altered expression of microRNAs might be contributing to the process of autoimmunity. Thus, the study aim was to identify the expression profiles and interaction networks between a set of microRNAs and their mRNA targets in thymocytes and peripheral CD3+ T lymphocytes during the development of type 1diabetes (T1D) in NOD mice. The microarray technology was used to evaluate the expression of mRNAs as possible targets of microRNAs involved in this process. The use of bioinformatics software to reconstruct the networks was essential. It was realized that complex phenomena as post-transcriptional regulation in T cells and their involvement in the immune tolerance process, as well as the emergence of autoimmune diseases can be better understood only by means of functional genomics. The results show differential expression of mRNAs and microRNAs in thymocytes and peripheral CD3+ T lymphocytes during the development of type 1 diabetes (T1D). The differences found in the transcriptional profiles involve mRNAs related to the immune system, differentiation and activation of T lymphocytes and apoptosis as well as other processes related to immune response. In addition, the microRNA-mRNA interaction networks obtained in this study evidence the predicted interactions as well as new ones, showing the participation of a group of microRNAs that may be acting in post-transcriptional control of type 1 diabetes in NOD mice contributing to a better understanding of the molecular genetic control of autoimmune diseases in specially type 1 diabetes.

Abstract Hypoglycaemia may contribute to the nocturnal occurrence of sudden death in type 1 diabetes. The impact of hypoglycaemia on cardiac autonomic regulation and electrical properties is a potential factor predisposing patients to fatal arrhythmic events.This study was designed to assess the effects of hypoglycaemia on cardiovascular autonomic regulation and cardiac repolarisation in type 1 diabetic patients and their non-diabetic counterparts during experimental and spontaneous hypoglycaemia. Sixteen subjects with type 1 diabetes and eight healthy controls participated in experimental hypoglycaemia induced by using glucose clamp technique. Altogether 37 patients with type 1 diabetes were evaluated in real-life situation by using continuous glucose monitoring system. Ten of those individuals participated in additional experiment to determine the effect of sympathetic activation on the cardiac autonomic regulation. Continous electrogram recordings were used to analyze heart rate variability (HRV) and cardiac repolarisation. During experimental hypoglycaemia, cardiac vagal activity, assessed by the high frequency (HF) component and beat-to-beat R-R interval variability (SD1), decreased progressively with no differences among diabetic or non-diabetic subjects. Controlled hypoglycaemia evoked profound changes in cardiac repolarisation. These changes tended to be even more evident in the diabetic subjects compared to those encountered in their healthy counterparts. During spontaneous hypoglycaemia, the low frequency (LF) component of HRV decreased significantly and correlated positively with the change in the glucose concentration. The muscle sympathetic nerve activity study confirmed that the reduction in the LF spectral component resulted mainly from pure sympathetic activation without any concomitant vagal withdrawal. Spontaneous hypoglycaemia induced significant changes in T-wave loop morphology. The QT interval corrected for heart rate by Bazett´s formula and by the nomogram method shortened during hypoglycaemia. The present observations indicate that hypoglycaemia has major impacts on cardiac autonomic regulation and repolarisation which may partly explain the vulnerability of these individuals to life-threatening cardiac arrhythmias and may have some clinical importance in contributing to the occurrence of ´dead-in-bed` syndrome. / Tiivistelmä Hypoglykemia saattaa vaikuttaa yöllisten äkkikuolemien ilmaantuvuuteen tyypin 1 diabetesta sairastavilla. Hypoglykemian vaikutus sydämen autonomiseen toimintaan ja sähköisiin ominaisuuksiin voi altistaa potilaat kuolemaan johtaville rytmihäiriölle. Tämän tutkimuksen tarkoitus oli selvittää hypoglykemian vaikutuksia kardiovaskulaarisen autonomisen toiminnan säätelyyn ja sydämen repolarisaatioon tyypin 1 diabetesta sairastavilla ja heidän terveillä verrokeillaan kokeellisen ja spontaanin hypoglykemian aikana. Kuusitoista diabetesta sairastavaa ja 8 verrokkipotilasta osallistuivat kokeellisen hypoglykemian tutkimukseen. Yhteensä 37 tyypin 1 diabetesta sairastavaa seurattiin jatkuvan sokeriseurannan laitteella kotioloissa. Kymmenen heistä osallistui jatkotutkimukseen, jossa selvitettiin sympaattisen aktivaation vaikutusta sydämen autonomisen toiminnan säätelyyn. Jatkuvaa sydänfilmin rekisteröintiä käytettiin sydämen sykevaihtelun ja repolarisaation analysoinnissa. Kokeellisen hypoglykemian aikana sydämen vagaalinen aktiivisuus määriteltynä korkean taajuuden (HF) komponentin osuutena ja R-R-välin vaihteluna (SD1) väheni progressiivisesti sekä diabetesta sairastavilla että verrokeilla. Kontrolloitu hypoglykemia aiheutti huomattavia muutoksia sydämen repolarisaatioon. Nämä muutokset olivat jopa suurempia diabetesta sairastavilla kuin heidän terveillä verrokeillaan. Spontaanin hypoglykemian aikana sykevaihtelun matalan taajuuden (LF) komponentin osuus pieneni huomattavasti ja korreloi positiivisesti sokeripitoisuuden muutokseen. Lihaksen sympaattisen hermoston aktiivisuutta koskeva tutkimus vahvisti, että matalan taajuuden osuuden pieneneminen johtui pääasiassa sympaattisesta aktivaatiosta eikä niinkään vagaalisen osuuden pienenemisestä. Spontaani hypoglykemia aiheutti merkittäviä muutoksia T-aallon sähköisen silmukan morfologiaan. Bazett’n kaavalla ja nomogrammimenetelmällä korjattu QT-väli lyheni hypoglykemian aikana. Tehdyt havainnot osoittavat, että hypoglykemialla on sellaisia merkittäviä vaikutuksia sydämen autonomisen toiminnan säätelyyn ja repolarisaatioon, jotka voivat osittain selittää näiden yksilöiden alttiuden henkeä uhkaaville rytmihäiriöille. Näillä muutoksilla voi olla kliinistä merkitystä ns. ”dead in bed”-oireyhtymän esiintymisessä.

The inference of gene regulatory networks (GRN) is of great importance to medical research, as causal mechanisms responsible for phenotypes are unravelled and potential therapeutical targets identified. In type 1 diabetes, insulin producing pancreatic beta-cells are the target of an auto-immune attack leading to apoptosis (cell suicide). Although key genes and regulations have been identified, a precise characterization of the process leading to beta-cell apoptosis has not been achieved yet. The inference of relevant molecular pathways in type 1 diabetes is then a crucial research topic. GRN inference from gene expression data (obtained from microarrays and RNA-seq technology) is a causal inference problem which may be tackled with well-established statistical and machine learning concepts. In particular, the use of time series facilitates the identification of the causal direction in cause-effect gene pairs. However, inference from gene expression data is a very challenging problem due to the large number of existing genes (in human, over twenty thousand) and the typical low number of samples in gene expression datasets. In this context, it is important to correctly assess the accuracy of network inference methods. The contributions of this thesis are on three distinct aspects. The first is on inference assessment using precision-recall curves, in particular using the area under the curve (AUPRC). The typical approach to assess AUPRC significance is using Monte Carlo, and a parametric alternative is proposed. It consists on deriving the mean and variance of the null AUPRC and then using these parameters to fit a beta distribution approximating the true distribution. The second contribution is an investigation on network inference from time series. Several state of the art strategies are experimentally assessed and novel heuristics are proposed. One is a fast approximation of first order Granger causality scores, suited for GRN inference in the large variable case. Another identifies co-regulated genes (ie. regulated by the same genes). Both are experimentally validated using microarray and simulated time series. The third contribution of this thesis is on the context of type 1 diabetes and is a study on beta cell gene expression after exposure to cytokines, emulating the mechanisms leading to apoptosis. 8 datasets of beta cell gene expression were used to identify differentially expressed genes before and after 24h, which were functionally characterized using bioinformatics tools. The two most differentially expressed genes, previously unknown in the type 1 Diabetes literature (RIPK2 and ELF3) were found to modulate cytokine induced apoptosis. A regulatory network was then inferred using a dynamic adaptation of a state of the art network inference method. Three out of four predicted regulations (involving RIPK2 and ELF3) were experimentally confirmed, providing a proof of concept for the adopted approach. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Abstract Type 1 diabetes mellitus (T1DM) among children is of a particular importance in Finland, where its incidence is the highest in the world and still increasing. However, the aetiology of T1DM is not fully known. According to current knowledge, both genetic and environmental factors operate together, leading to an attack by the immune system on the insulin-producing beta cells. The purpose of this study was to investigate the geographical variation in the incidence of T1DM among children aged up to 14 years in Finland. Geographical Information Systems (GIS) and Bayesian spatial statistics were applied in a search for unusual spatial patterns and risk factor associations. The incidence of T1DM among children aged up to 14 years showed clear geographical variations in Finland. Living in a rural environment increased the risk for T1DM, and the risk was particularly high among children living in rural heartland areas. There was no association between the variation in T1DM incidence and the zinc and nitrate concentrations of drinking water. A male excess in the incidence of T1DM was seen in the low-incidence areas. The geographical variation in the risk of T1DM was marked only among children aged up to 9 years. Because genetics is a necessary but not a sufficient cause of T1DM, it could be hypothesized that there are some thus far unknown environmental risk factors affecting particularly younger children in Finland. Some of those factors may be related to a rural environment. The geographical variation in the M/F ratio of T1DM was a challenging observation and warrants more analytical study.

ABSTRAKT Bakgrund: Typ 1-diabetes är en kronisk autoimmun sjukdom som kräver daglig administrering av insulin. Det är vanligt att föräldrar är oroade över de allvarliga komplikationerna av sjukdomen som kan drabba deras ungdom. Med ungdomens stigande ålder infaller ofta en kamp för självständighet från sina föräldrar. Sjuksköterskan har en viktig roll i att stödja föräldrarna genom denna process. Syfte: Syftet med denna studie var att belysa föräldrars upplevelser av att leva med en ungdom (10–19 år) diagnostiserad med typ 1-diabetes. Metod: En litteraturstudie baserad på elva kvalitativa artiklar analyserade med hjälp av innehållsanalys.    Resultat: Studiens huvudsakliga resultat belyser vikten av att som förälder kunna adaptera till en ny livssituation i och med ungdomens diabetesdiagnos. Föräldrar upplevde svårigheter med att hitta rätt grad av involvering och uppgav ett ökat behov av stöd, både personligen och i samband med ungdomens övergång mot självständighet. Slutsats: Att vara förälder till en ungdom med typ 1-diabetes är komplicerat. Som sjuksköterska är det av stor betydelse att förstå denna komplexitet. Sjuksköterskan bör ha en grundläggande förståelse för hur diabetes kan ha en stor inverkan på hela familjelivet och att diagnosen innebär en ny livssituation som både tonåringar och föräldrar måste anpassa sig till. / ABSTRACT Background: Type 1 diabetes is a chronic autoimmune disease that requires daily administration of insulin. It is common for parents to feel concerned about the serious complications of the disease that may affect their adolescents. As the adolescent grows older, a struggle for independence from their parents often occurs and the nurse plays an important role in supporting parents through this process. Purpose: The purpose of this study was to highlight experiences of parents living with an adolescent (10–19 years) diagnosed with type 1 diabetes. Method: A literature study based on eleven qualitative articles analyzed using content analysis. Results: The main findings of the study highlighted the importance for parents to adapt to a new life situation with the adolescent's diabetes diagnosis. Parents also experienced difficulties finding the right level of involvement, and stated an increased need for support both personally and when the adolescent is transitioning into being independent. Conclusion: Being a parent of an adolescent with type 1 diabetes is complicated. As a nurse it is therefore of great importance to understand this complexity. The nurse should have a fundamental understanding of how diabetes can have a major impact on the whole family life and that the diagnosis implies a new life situation that both adolescents and parents must adapt to.