Spelling suggestions: "subject:"diabetes mellitus, type 2"" "subject:"diabetes mellitus, mype 2""
221 |
Efeito do diabetes mellitus, tipo 2, na musculatura do sistema estomatognático - avaliação eletromiográfica, espessura muscular e força de mordida / Effect of diabetes mellitus, type 2, in muscles of the stomatognatic system: eletromyographic evaluation, muscular thickness and bite forceOliveira, Richard Honorato de 06 June 2014 (has links)
Considerando-se a relevância da influência da musculatura na funcionalidade do sistema estomatognático, buscou-se com este trabalho realizar avaliação do comportamento e atuação da musculatura mastigatória em indivíduo diabético, tipo 2. Este estudo teve como objetivo comparar a atividade eletromiográfica, a espessura dos músculos masseter e temporal e a força de mordida entre indivíduos portadores de diabetes (GD) e um grupo controle (GC), saudáveis. A atividade eletromiográfica foi avaliada utilizando o eletromiógrafo Myosystem BR-1 nas condições posturais da mandíbula e na mastigação não-habitual de Parafilme M® e habitual de uvas passas e amendoins. Para a análise da espessura muscular foram adquiridas imagens dos músculos masseter e temporal no repouso e na contração voluntária máxima utilizando o aparelho de ultrassom SonoSite Titan. A força de mordida molar máxima direita e esquerda foi obtida por meio do dinamômetro digital Kratos. Os dados coletados foram submetidos ao tratamento estatístico utilizando testes de comparação (teste t de Student), considerando o intervalo de confiança de 95% (SPSS 20.0). Os resultados obtidos nesta pesquisa revelaram que os indivíduos com diabetes apresentaram na atividade eletromiográfica diferença estatisticamente significante apenas na condição de mastigação de Parafilme M®para os músculos temporais esquerdo e direito (p<0,05). Na análise ultrassonográfica verificou-se maior espessura muscular para os masseteres e menor espessura para os temporais no grupo diabético quando comparado ao grupo controle, estatísticamente significante. Com relação à força de mordida, observou-se que nos indivíduos diabéticos, a força de mordida foi menor, sem significância estatística. Concluiu-se que, os músculos masseteres e temporais dos diabéticos, tipo 2, sofreram alterações eletromiográficas e em suas espessuras, o que requer do cirurgião-dentista oferecer tratamentos odontológicos que reabilitem com maior eficiência seus pacientes diabéticos. / Considering the importance of the influence of the muscles in the functionality of the stomatognathic system, we sought to carry out this work evaluation of the behavior and performance of the masticatory muscles in diabetic subjects, type 2. This study aimed to compare the electromyographic activity, the thickness of masseter and temporalis muscles and bite force among individuals with diabetes (GD) and healthy control group (GC). The electromyographic activity was assessed using electromyography Myosystem BR-1 in postural conditions of the jaw and non-habitual chewing Parafilm M®and habitual chewing of raisins and peanuts. For the analysis of muscle thickness were acquired images of the masseter and temporal muscles at rest and at maximum voluntary contraction using the SonoSite Titan ultrasound machine. The maximum bite force, right and left molar, was obtained through digital dynamometer Kratos. The data collected were subjected to statistical analysis using comparison tests (Student\'s t test) , considering a confidence interval of 95 % (SPSS 20.0). The results obtained in this study revealed that individuals with diabetes showed the statistically significant difference electromyographic activity only on condition chewing Parafilm M® for left and right in temporal muscles (p< 0.05). On ultrasound examination, there was greater muscle thickness for the masseter and temporal thickness less for the diabetic group compared to controls, statistically significant difference. With respect to bite force, it was observed that in diabetic patients, the bite force was lower without statistical significance. It was concluded that the masseter and temporal muscles of diabetics, type 2, suffered electromyographic changes and their thicknesses, which requires the dentist to provide dental treatments that more effectively rehabilitate their diabetic patients.
|
222 |
Intervenções educativas para o autocuidado dos pés de pacientes com diabetes mellitus: estudo quase experimental / Educational interventions for self-care of the feet of patients with diabetes mellitus: a quasi-experimental studyFonseca, Natália Máximo 03 July 2018 (has links)
Este é um estudo quase-experimental, cujo objetivo foi avaliar as contribuições de uma intervenção educativa, focada no autocuidado com os pés, para as pessoas com diabetes mellitus tipo 2, desenvolvida em unidade ambulatorial de um hospital de nível terciário do interior paulista em amostra de 27 pessoas com diabetes mellitus tipo 2. A intervenção educativa teve duração de 12 meses, estruturada em quatro encontros, dos quais dois foram individuais e utilizados para realizar a coleta de dados, nos dois tempos do estudo, que ocorreram antes e após o programa educativo, respectivamente, e dois na modalidade grupal, nos quais foram desenvolvidas as intervenções educativas por meio de ferramentas visuais e interativas, denominada Mapa de Conversação em Diabetes, cujas intervenções foram fundamentadas na Teoria Social Cognitiva que tem como conceito chave a Auto Eficácia. A amostra foi caracterizada pelas variáveis sociodemográficas, clínicas, antropométricas, tratamento e hábitos de vida. As variáveis de interesse foram: avaliação física dos pés e calçados, o comportamento planejado em relação ao cuidado com os pés, a autoeficácia e a hemoglobina glicada. Os dados de caracterização da amostra foram apresentados por meio da estatística descritiva e as análises entre os tempos antes e após a intervenção educativa foi realizado através do teste Mann-Whitney para os instrumentos de Comportamento Planejado e Autoeficácia, já para efetuar a correlação entre os domínios da Autoeficácia, foi utilizado o coeficiente de correlação de Spearman e para avaliar as questões relacionadas à avaliação dos pés utilizou-se o teste Exato de McNemar. O nível de significância adotado em todas as análises foi de 5% (? = 0.05). Na caracterização da amostra houve predomínio do sexo feminino 20(62,5%), 61,12 (DP=8,94) anos de idade, tempo médio de diagnóstico 19,25 (DP=10,50) anos. As características físicas dos pés da amostra estudada apresentaram melhora em quase todas as variáveis avaliadas com o valor de p? 0,05, exceto para a questão sobre \"presença de descamações\" e \"lesões interdigitais\" cujo valor de p foi >0,05 para ambos. No item cuidado com os pés do comportamento planejado, o domínio cujo escore aumentou após as intervenções foi o relacionado ao \"planejamento do coping\" (p>0,05). Para este último resultado atribui-se uma relevância clínica ao considerar uma variável cuja natureza se insere na esfera psicológica. Para a autoeficácia, a média total da escala aumentou após o programa educativo, de 2,17 (DP=0,65) para 2,28 (DP=0,46) (p<0,05), com destaque ao domínio que inclui cuidados com os pés. A hemoglobina glicada apresentou diminuição de 0,544% no valor médio entre os dois tempos do estudo, de 8,434% para 7,890% (p>0,05). Os resultados do presente estudo contribuíram com a melhora dos cuidados com os pés das pessoas com diabetes mellitus / This is almost an experimental study with the objective of assessing the contributions of an educative intervention, focused on the self-care of the feet of people with diabetes mellitus type 2. It was developed in the ambulatory of a thirdsector hospital, in the countryside of State of São Paulo, sampling 27 people with diabetes mellitus type 2. The educative intervention had the duration of 12 months. Its was structured with four meetings, in which two were individual and used to perform data collection, on both periods of the study, that occurred before and after the educative program, respectively. Two meetings were in group, in which the educative interventions were performed, using audiovisual, interactive aids named Diabetes Conversation Map [Mapa de Conversação em Diabetes], focusing on the concept of self-efficacy Social Cognitive Theory. The sample was characterized by the sociodemographic, clinic and anthropometric variables, and also treatment and lifestyle. In the interest analysis, were included the variables of physical evaluation of the feet and shoes, the planned behavior regarding the feet care, the self-efficacy and the impact on the glycated hemoglobin. The sample data characterization was presented using the descriptive statistic and the analysis of the situation before and after the educative intervention was performed through the Mann-Whitney test, for the tools of planned behavior and self-efficacy. To perform the correlation between the domains of self-efficacy, the Spearman correlation coefficient was used and to asses the feet evaluation, the McNemar\'s test. The significance level adpted in all analysis was 5% (? = 0.05). Th the sample characterization there was the predominance of the female sex 20 (62,5%), and elder adults with the average of 61,12 (DP = 8,94) years old, average diagnostic time 19,25 (DP = 10,50) years. The physical characteristics of the feet in the studied sample presented improvement in almost every variable assessed with the value of p<0,05, except for the topics \"peeling\" and \"interdigital injuries\", with the value of p>0,05 for both. As for the tool \"planned behavior\", regarding the feet care, the domain that presented increase was \"coping plan\" in T4, however with the value of p>0,05. For the last, the result was due to a clinic relevance when considering a psychologicrelated variable. For the self-efficacy, the total average of the scale increased after the educative program, in T1 the average was 2,17 (DP=0,65) and T4 2,28 (DP=0,46), p<0,05. The educative program contributed positively to the variables of feet care, as observed in the results in domain 2 \"general nutrition and drug treatment\", that included one item of feet care. As for the glycated hemoglobin, the present study presented decrease of the average value between the two periods of study, 8.434% in T1 and 7.890% in T4, which means a decrease of 0.544% with the value of p>0.05. It is possible to state that the results showed positive contributions for people in the performance of feet self-care
|
223 |
Herdabilidade de fenótipos metabólicos em uma população brasileira: diabetes mellitus tipo 2 como modelo de aplicação / Heritability of metabolic phenotypes in a Brazilian population: type 2 diabetes mellitus as application modelPadilha, Kallyandra 06 May 2016 (has links)
O desenvolvimento de formas comuns de diabetes ocorre a partir da interação de fatores ambientais e genéticos. Como consequências da falta de controle glicêmico nesses pacientes várias complicações são geradas. Estudos metabolômicos para diabetes mellitus tipo 2 no soro/plasma relataram mudanças em vários metabólitos, os quais podem ser considerados possíveis alvos para futuras pesquisas mecanicistas. Como o diabetes mellitus tipo 2 é uma doença que altera o perfil metabólico em vários níveis, este trabalho teve como objetivo comparar os indivíduos com diabetes mellitus tipo 2 e com indivíduos não-diabéticos. Além disso, foram explorados o design exclusivo de um estudo de base familiar para trazer uma melhor compreensão da relação causal de metabólitos identificados e o diabetes. No presente estudo, metabolômica de base populacional foi realizada em 939 amostras de soro de indivíduos participantes do Projeto Corações de Baependi. Os participantes foram separados em dois grupos: diabéticos (77 indivíduos) e não-diabéticos (862 indivíduos). Com a técnica de GC/MS, normalização e análise estatística utilizadas, foi possível identificar metabólitos diferencialmente alterados em soro de diabéticos e não-diabéticos. Foram identificados 72 metabólitos com diferentes concentrações médias em indivíduos com diabetes mellitus tipo 2, em comparação com indivíduos saudáveis. Foi possível recapitular as principais vias que são alteradas no indivíduo diabético e a identificação de metabólitos sugestivos de estarem elevados no diabetes. Os dados de hereditariedade puderam ser utilizados para uma melhor compreensão da relação causal das associações observadas e ajudar a priorizar metabólitos associados ao diabetes para trabalhos futuros / The development of common forms of diabetes comes from the interaction between environmental and genetic factors, and the consequences of poor glycemic control in these patients can result in several complications. Metabolomics studies for type 2 diabetes mellitus in serum/plasma have reported changes in numerous metabolites, which might be considered possible targets for future mechanistic research. As type 2 diabetes is a disease that changes the metabolic profile in several levels, this work aimed to compare type 2 diabetes mellitus and non-diabetic participants of a family-based epidemiological study. In addition, we exploited the unique design of a family-based study to bring a better understanding of the causal relationship of identified metabolites and diabetes. In the current study, population based metabolomics was applied in 939 participants of \"the Baependi Heart Study\". Participants were separated into two groups: diabetic (77 individuals) and non-diabetic (862 individuals). By GC/MS technique, normalization and statistical analysis, it was possible to identify differentially concentrated metabolites in serum of diabetics and non-diabetics. 72 metabolites were identified as up regulated in type 2 diabetes mellitus subjects compared to non-diabetic individuals. It was possible to recapitulate the main pathways that are changed in the diabetic subject and the identification of metabolites suggestive of being upstream of diabetes. Heritability data was used to derive a better understanding of the causal relationship of the observed associations and help to prioritize diabetes-associated metabolites for further work
|
224 |
GLP-1 receptor agonist exendin-4 improves glycemic control through beta cell and non-beta cell mechanism. / CUHK electronic theses & dissertations collectionJanuary 2011 (has links)
Fan, Rongrong. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 130-150). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
|
225 |
Feasibility study of a randomized controlled trial protocol to examine the effectiveness of auriculotherapy (AT) in improving sleep condition and glycaemic control in clients with type 2 diabetes. / CUHK electronic theses & dissertations collectionJanuary 2013 (has links)
Kwan, Yee Mei. / Thesis (D.Nurs.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 152-171). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese; appendixes includes Chinese.
|
226 |
The role of calcitriol in regulation of hepatic lipid and glucose metabolism with insulin resistance. / CUHK electronic theses & dissertations collectionJanuary 2013 (has links)
Cheng, Suosuo. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 159-173). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts aslo in English.
|
227 |
Protective mechanism(s) of anti-oxidants in pancreatic-islet β-cells against glucose toxicity and oxidative stress. / Protective mechanism(s) of anti-oxidants in pancreatic-islet beta-cells against glucose toxicity and oxidative stressJanuary 2011 (has links)
Poon, Chui Wa Christina. / "August 2011." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 123-131). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 論文摘要 --- p.vi / ACKNOWLEDGEMENTS --- p.ix / PUBLICATIONS --- p.x / Abstracts --- p.x / ABBREVIATIONS --- p.xii / Chapter 1. --- GENERAL INTRODUCTION --- p.1 / Chapter 1.1. --- Diabetes --- p.1 / Chapter 1.1.1. --- Overview --- p.1 / Chapter 1.1.2. --- Diagnostic Criteria of Type-2 Diabetes --- p.2 / Chapter 1.1.3. --- Type-2 Diabetes (T2DM) --- p.3 / Chapter 1.1.3.1. --- Impaired Insulin Synthesis and Insulin Secretory Defects in Type-2 Diabetes --- p.3 / Chapter 1.1.3.2. --- β-Cell Dysfunction --- p.5 / Chapter 1.1.3.3. --- Insulin Resistance --- p.5 / Chapter 1.1.4. --- Glucose Toxicity --- p.6 / Chapter 1.1.4.1. --- Fasting Hyperglycemia --- p.8 / Chapter 1.1.4.2. --- Postprandial Hyperglycemia --- p.8 / Chapter 1.2. --- Oxidative Stress --- p.8 / Chapter 1.2.1. --- ROS and Mitochondria --- p.8 / Chapter 1.2.2. --- ROS Production by Mitochondria --- p.9 / Chapter 1.2.3. --- The Relationship of Glucose Recognition by β-cells and Oxidative Stress --- p.11 / Chapter 1.2.4. --- Important Roles of Glutathione in Pancreatic β-cells and Glutathione Synthesis --- p.14 / Chapter 1.2.5. --- N-acetyl-L-cysteine - A Potential Drug Treatment for Type-2 Diabetes? --- p.17 / Chapter 1.3. --- Role of F-actin Cytoskeleton on Glucose-induced Insulin Secretion --- p.18 / Chapter 1.4. --- Current Clinical Treatments for Type-2 Diabetes Mellitus --- p.21 / Chapter 1.4.1. --- Metformin --- p.22 / Chapter 1.4.2. --- Sulfonylureas --- p.22 / Chapter 1.4.3. --- Thiazolidinediones --- p.23 / Chapter 1.4.4. --- Glinides (Meglitinide Analogues) --- p.23 / Chapter 1.4.5. --- α-Glucosidase (AG) Inhibitors --- p.24 / Chapter 1.4.6. --- Dipeptidyl Peptidase-4 (DPP-4) Inhibitors --- p.24 / Chapter 1.4.7. --- (Clinical) Antioxidant Treatment --- p.24 / Chapter 1.5. --- Animal Models Used in Type-2 Diabetes Research --- p.25 / Chapter 1.6. --- Aims of Study --- p.27 / Chapter 2. --- RESEARCH DESIGN & METHODS --- p.28 / Chapter 2.1. --- Materials --- p.28 / Table 1. Sources and concentrations of drugs tested in this study: --- p.28 / Culture Medium - --- p.29 / General Reagents --- p.29 / Chapter 2.2. --- Isolation of Islets of Langerhans and Single Pancreatic β-Cells --- p.31 / Chapter 2.3. --- Measurement of Mitochondrial ROS Levels --- p.32 / Chapter 2.4. --- Measurement of Islets Insulin Release and Insulin Content --- p.34 / Chapter 2.4.1. --- Preparation of Samples --- p.34 / Chapter 2.4.2. --- Enzyme-Link Immunosorbent Assay (ELISA) --- p.35 / Chapter 2.5. --- Immunocytochemistry --- p.35 / Chapter 2.6. --- Data and Statistical Analysis --- p.37 / Chapter 3. --- RESULTS --- p.38 / Chapter 3.1. --- "Effects of L-NAC, Various Oxidative Stress Inducers/Reducers and Actin Polymerisation/Depolymerisation Inducers on Releasable Insulin Levels and Insulin Contents in Response to Low Glucose (5 mM) and High Glucose (15 mM) of Isolated Pancreatic Islets of (db+/m+) and (db+/db+) Mice" --- p.38 / Chapter 3.1.1. --- Effect of L-NAC on Insulin Secretion and Insulin Contents --- p.38 / Chapter 3.1.2. --- Effect of Cytochalasin B on Insulin Secretion and Insulin Contents --- p.39 / Chapter 3.1.3. --- Effect of 4-Phenyl Butyric Acid on Insulin Secretion and Insulin Contents --- p.43 / Chapter 3.1.4. --- Effect of Ursodeoxycholic Acid on Insulin Secretion and Insulin Contents --- p.46 / Chapter 3.1.5. --- Effect of Hydrogen Peroxide on Insulin Secretion and Insulin Contents --- p.49 / Chapter 3.1.6. --- Effect of Jasplakinolide on Insulin Secretion and Insulin Contents --- p.53 / Chapter 3.1.7. --- Effect of Thapsigargin on Insulin Secretion and Insulin Contents --- p.57 / Chapter 3.1.8. --- Effect of BSO on Insulin Secretion and Insulin Contents --- p.61 / Chapter 3.2. --- "Effects of L-NAC, Various Oxidative Stress Inducers/Reducers and Actin Polymerisation/Depolymerisation Inducers on Mitochondrial ROS Levels in Response to High Glucose (15 mM) Challenge in Isolated Single Pancreatic β-Cells of (db +/m+) and (db +/db +) Mice" --- p.65 / Chapter 3.2.1. --- "Effects of L-NAC (20 mM), 4-Phenyl Butyric Acid (4-PBA) (1 mM), Ursodeoxycholic Acid (UA) (500 μg/ml), H202 (200 μM), Thapsigargin (0.5 μM) and DL-Buthionine-[S,R]-Sulfoximine (BSO) (0.1 μM) Pre-treatments on Mitochondrial ROS Level in Response to High Glucose (15 mM) Challenge" --- p.65 / Chapter 3.2.2. --- "Effects of L-NAC (20 mM), Cytochalasin B (10 μM) and Jasplakinolide (5 μM) Pre-treatments on Mitochondrial ROS Level in Response to High Glucose (15 mM) Challenge_" --- p.76 / Chapter 3.3. --- "Effects of L-NAC, Various Oxidative Stress Inducers/Reducers and Actin Polymerisation/Depolymerisation Inducers on F-actin Cytoskeleton Levels Incubated in Low Glucose (5 mM) and High Glucose (15 mM) Medium in Single Pancreatic β-Cells of Non-Diabetic (db +/m+) and Diabetic (db +/db +) Mice" --- p.81 / Chapter 4. --- DISCUSSION --- p.100 / Chapter 4.1. --- General Discussion --- p.100 / Chapter 5. --- SUMMARY --- p.120 / Chapter 6. --- FUTURE PERSPECTIVES --- p.121 / Chapter 7. --- REFERENCES --- p.123
|
228 |
The role of cystic fibrosis transmembrane conductance regulator in insulin secretion in pancreatic islet β-cells. / Role of cystic fibrosis transmembrane conductance regulator in insulin secretion in pancreatic islet beta-cells / CUHK electronic theses & dissertations collectionJanuary 2013 (has links)
囊性纖維化(CF)是由囊性纖維化跨膜電導調節器(CFTR)的突變引起的一種隱性遺傳病。CF病人的肺、肝、胰腺、腸道與生殖道受到嚴重影響,其中有50%的成年病人患有糖尿病。由CF引起的糖尿病被稱為CF相關糖尿病(CFRD), 关于它的病因至今仍然存有爭議。2007年,人們發現CFTR在分泌胰島素的胰島β細胞上有表達。儘管如此,β細胞上的CFTR与糖尿病发病的关系却一直被忽略。我們的研究目標是闡述β細胞上的CFTR在胰島素分泌中的作用。 / 在β細胞上,葡萄糖刺激的胰島素分泌伴隨著複雜的電活動,這種電活動被描述為細胞膜電位去极化疊加的動作電位的爆發。葡萄糖引起的ATP敏感的鉀離子通道(K[subscript Asubscript Tsubscript P])的關閉被普遍認為是β細胞去極化的初始事件,初始的去極化啟動了電壓依賴的鈣離子通道,由此產生的鈣離子內流成為構成動作電位的去極化電流,引起了細胞內鈣離子的震盪,從而引起胰島素的釋放。雖然氯離子電流被認為參與了β細胞去極化電流,但是,人們仍然不能確定是哪一種氯離子通道介導了這個去極化電流。在我們研究的第一部分,CFTR被證明功能性的表達在β細胞上,並且可以被葡萄糖激活。CFTR可以被葡萄糖激活这一性质,在CFTR超表達的CHO 细胞上被進一步驗證。在原代培養的β細胞與β細胞株RIN-5F细胞中的葡萄糖引起的全細胞電流、膜電位的去極化、動作電位的幅度與頻率、鈣震盪和胰島素的分泌可以被CFTR的抑制劑或缺陷所降低。與野生型小鼠相比,CFTR基因敲除的小鼠,禁食之後,具有更高的血糖濃度,然而其胰島素的濃度低。 / 我們研究中的第二部分,利用了數學模型去闡明CFTR 在胰島素分泌的電活動中的角色。結果顯示, CFTR電導的減低可以使細胞的細胞膜去極化,從而導致需要更高的電刺激去引發動作電位,这些結果證明了CFTR對於维持細胞膜電位的貢獻。同時增加細胞內氯離子濃度和CFTR的電導可以引起更大頻率的膜電位的震盪,這一點證明了氯離子對於細胞膜電位震盪有著重要的作用。在数学模型中,CFTR電導的降低可以消除通過改變ATP/ADP值所引起的電火花, 這與我們在試驗中發現的CFTR參與了葡萄糖引起的動作電位是一致的。總而言之,我們的数学模型證明了CFTR對於胰島素的分泌是非常重要的,它通過介導氯離子外流對細胞膜電位的產生貢獻並且參與了電火花的產生,所有這些都進一步驗證了我們在實驗部分的發現。 / 综上所述,現有的研究揭示了CFTR,通過對β細胞膜電位作用與参与了動作電位的產生,在葡萄糖刺激胰島素分泌过程中的鮮為人知的重要角色。這個發現為揭示CFRD的病理機制提供了全新的視角,並且可能為開發治療CFRD的方法帶来了曙光。 / Cystic fibrosis (CF) is a recessive autosomal genetic disease resulted from mutations of cystic fibrosis transmembrane conductance regulator (CFTR). CF affects critically the lung, liver, pancreas, intestine and reproductive tract. CF patients also exhibit a high percentage of diabetes, which almost reach 50% in adult. The pathological cause of diabetes in CF patients, also called CF related diabetes (CFRD), is still controversial. It has been reported that CFTR expressed in the islet β cells, which is responsible for insulin secretion. However, the exact role of CFTR in islet β-cell and its relation to diabetes have been ignored. The present study aims to elucidate the role of CFTR in the process of insulin secretion by pancreatic islet β cells. / Glucose-stimulated insulin secretion is associated with a complex electrical activity in the pancreatic islet β-cell, which is characterized by a slow membrane depolarization superimposed with bursts of action potentials. Closing ATP-sensitive K⁺ channels (K[subscript Asubscript Tsubscript P]) in response to glucose increase is generally considered the initial event that depolarizes the β-cell membrane and activates the voltage-dependent Ca²⁺ channels, which constitutes the major depolarizing component of the bursting action potentials giving rise to the cytosolic calcium oscillations that trigger insulin release. While Cl⁻ has been implicated in an unknown depolarization current of the β-cell, the responsible Cl⁻ channel remains unidentified. In the first part of our study, we show functional expression of CFTR and its activation by glucose in the β-cell. Activation of CFTR by glucose was also demonstrated in CHO cell over-expression system. The glucose-elicited whole-cell currents, membrane depolarization, electrical bursts (both magnitude and frequency), Ca²⁺ oscillations and insulin secretion could be abolished or reduced by inhibitors/knockdown of CFTR in primary mouse β-cells or RIN-5F β-cell line, or significantly attenuated in isolated mouse islet β-cells from CFTR mutant mice compared to that of wildtype. Significantly increased blood glucose level accompanied with reduced level of insulin is found in CFTR mutant mice compared to the wildtype. The results strongly indicate a role of CFTR in the process of insulin secretion. / In the second part of our study, mathematical model is built up to clarify the role of CFTR in the electrical activity during insulin secretion. It is shown that reduction of CFTR conductance hyperpolarizes the membrane of the β-cell, for which it requires a larger electrical stimulus to evoke an action potential, indicating the contribution of CFTR to the membrane potential as demonstrated by our experimental results. Increase in intracellular Cl⁻ concentration and the conductance of CFTR result in higher frequency of membrane potential oscillations, demonstrating that Cl⁻ is crucial for the membrane potential oscillations. The electrical spikes induced by increase of ATP/ADP in the model are abolished by decreasing CFTR conductance, which is consistent with our findings that CFTR is involved in the generation of action potentials induced by glucose. In other word, our model demonstrates that CFTR is crucial for insulin secretion by its contribution to membrane potential and participating in the generation of electrical spikes via conducting Cl⁻ efflux, which confirms our findings in the experimental study. / Taken together, the present study reveals a previously unrecognized important role of CFTR in glucose-stimulated insulin secretion via contributing to the membrane potential and the participating in the generation of action potential in islet β cells. This finding sheds new light into the understanding of the pathogenesis of CFRD and may provide grounds for the development of new therapeutic approaches for CFRD. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Guo, Jinghui. / "December 2012." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 156-164). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract --- p.i / 摘要: --- p.iii / Acknowledgement: --- p.v / LIST OF PUBLICATIONS --- p.vi / Declaration --- p.viii / ABBREVIATIONS --- p.xi / LIST OF FIGURES --- p.xiii / Chapter Chapter 1: --- General introduction --- p.1 / Chapter 1.1 --- The function of islet β cells and diabetes --- p.1 / Chapter 1.1.1 --- The introduction of the pancreas --- p.1 / Chapter 1.1.2. --- Glucose metabolism and blood glucose regulation --- p.6 / Chapter 1.1.2.2 --- Blood glucose regulation --- p.7 / Chapter 1.1.3 --- Insulin secretion by the islet β cell --- p.10 / Chapter 1.1.4 --- Diabetes --- p.14 / Chapter 1.2 --- Cystic fibrosis-related diabetes --- p.17 / Chapter 1.2.1 --- Cystic fibrosis --- p.17 / Chapter 1.2.2 --- CFTR --- p.19 / Chapter 1.3 --- Mathematical model for insulin secretion --- p.25 / Chapter 1.4 --- Aim and hypothesis --- p.27 / Chapter 1.4.1 --- CFTR may be activated by glucose --- p.27 / Chapter 1.4.2 --- Activation of CFTR may depolarize the membrane potential --- p.28 / Chapter 1.4.3 --- CFTR-mediating Cl-efflux may be involved in the generation of electrical spikes --- p.28 / Chapter 1.4.4 --- Calcium oscillation depends on CFTR --- p.28 / Chapter 1.4.5 --- Insulin secretion --- p.29 / Chapter 1.5 --- Approaches to test the hypothesis --- p.29 / Chapter Chapter 2: --- Materials and Methods --- p.31 / Chapter 2.1 --- Cell culture --- p.31 / Chapter 2.1.1 --- RIN-5F cell --- p.31 / Chapter 2.1.2 --- CHO cell --- p.31 / Chapter 2.2 --- Islet isolation and culture --- p.32 / Chapter 2.3 --- CFTR knockdown --- p.33 / Chapter 2.4 --- Western blot --- p.35 / Chapter 2.5 --- Immunofluorescence --- p.37 / Chapter 2.6 --- Membrane potential (Vm) measurement --- p.38 / Chapter 2.7 --- Intracellular chloride imaging --- p.39 / Chapter 2.8 --- Intracellular calcium imaging --- p.40 / Chapter 2.9 --- Patch-clamp --- p.40 / Chapter 2.10 --- Blood glucose measurement --- p.42 / Chapter 2.11 --- Insulin ELISA --- p.42 / Chapter 2.12 --- Statistics --- p.42 / Chapter Chapter 3: --- Contribution of CFTR on the eletrophysiological properties in insulin secretion --- p.43 / Chapter 3.1 --- Introduction --- p.43 / Chapter 3.2 --- Results --- p.45 / Chapter 3.2.1 --- Functional expression of CFTR in mouse islet β cells --- p.45 / Chapter 3.2.2 --- CFTR activation by glucose --- p.46 / Chapter 3.2.3 --- Involvement of CFTR in the maintenance of membrane potential of islet β cells --- p.47 / Chapter 3.2.4 --- CFTR is involved in the generation of spikes induced by glucose --- p.50 / Chapter 3.2.5 --- Generation of spikes burst in the β cell depends on intracellular chloride. --- p.52 / Chapter 3.2.6 --- Inhibition/mutation of CFTR attenuates calcium oscillation induced by glucose --- p.53 / Chapter 3.2.7 --- Inhibition/mutation of CFTR impairs insulin secretion --- p.53 / Chapter 3.3 --- Discussion --- p.71 / Chapter Chapter 4: --- Mathematical model for the role of CFTR in the process of insulin secretion in islet β cell --- p.74 / Chapter 4.1 --- Introduction to the mathematical modeling in the process of insulin secretion --- p.74 / Chapter 4.2 --- Methods --- p.77 / Chapter 4.2.1 --- Components in the model --- p.77 / Chapter 4.2.2 --- Assumptions and approaches in modeling --- p.78 / Chapter 4.2.3 --- Modeling ion channels and transporters --- p.79 / Chapter 4.2.3.1 --- KATP channel --- p.79 / Chapter 4.2.3.2 --- Sodium channel --- p.82 / Chapter 4.2.3.3 --- Voltage Dependent calcium channel --- p.83 / Chapter 4.2.3.4 --- NCX --- p.84 / Chapter 4.2.3.5 --- Na-K pump --- p.85 / Chapter 4.2.3.6 --- Kv channel --- p.87 / Chapter 4.2.3.7 --- Ca pump --- p.88 / Chapter 4.2.3.9 --- CFTR --- p.90 / Chapter 4.2.3.10 --- NKCC --- p.91 / Chapter 4.3 --- Results --- p.93 / Chapter 4.3.1 --- Role CFTR in regulation of the basal membrane potential in β cells --- p.93 / Chapter 4.3.2 --- Role of intracellular chloride concentration in the burst spikes induced by glucose --- p.95 / Chapter 4.3.3 --- Role of CFTR in the burst spikes induced by glucose --- p.96 / Chapter 4.4 --- Discussion --- p.105 / Chapter Chapter 5: --- General discussion and conclusion --- p.109 / Chapter 5.1 --- General discussion --- p.109 / Chapter 5.1.1 --- Role of CFTR in endocrine pancreas and diabetes --- p.109 / Chapter 5.1.2 --- Role of CFTR as a cell metabolic sensor --- p.111 / Chapter 5.1.3 --- Role of CFTR in excitable cells --- p.113 / Chapter 5.2 --- Conclusion --- p.114 / Appendix A --- p.115 / Appendix B --- p.118 / Reference: --- p.156
|
229 |
Avaliação de marcadores inflamatórios séricos em indivíduos com diabetes mellitus tipo 2 após tratamento periodontal intensivo não-cirúrgico: estudo clínico randomizado / Evaluation of serum inflammatory markers in individuals with type 2 diabetes mellitus after intensive non-surgical periodontal therapy: a randomized clinical trial effectsHilana Paula Carillo Artese 27 August 2014 (has links)
O objetivo deste trabalho foi comparar os efeitos sorológicos e clínicos de dois protocolos de terapias periodontais em indivíduos com diabetes tipo 2 (DMT2) e periodontite crônica. Foram analisados 36 pacientes, randomizados em dois grupos: um grupo recebeu terapia intensiva de raspagem e alisamento radicular (INT; n=18) e outro recebeu apenas raspagem supragengival (SUP; n=18). Os grupos foram avaliados quanto aos parâmetros clínicos periodontais e marcadores inflamatórios séricos, antes e após 6 meses do tratamento periodontal. O exame clínico periodontal avaliou: placa visível (IP), índice gengival (IG), supuração (SUPUR), profundidade clínica de sondagem (PCS) e nível clínico de inserção (NCI). Amostras sanguíneas foram obtidas para análise de marcadores inflamatórios e hemoglobina glicada (HbA1c). Os marcadores de inflamação avaliados foram: interleucina (IL)-1, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, fator estimulador de colônias granulocitárias (G-CSF), fator estimulador de colônias de granulócitos-macrófagos (GM-CSF), interferon- (IFN-), proteína quimiotática de monócito-1 (MCP-1), proteína inflamatória de macrófago-1 (MIP-1) e fator de necrose tumoral (TNF-), através do imunoensaio multiplex (Bioplex). Ambas as terapias resultaram na melhora de quase todos os parâmetros clínicos periodontais (p<0,05), com exceção do NCI (p=0,09) no grupo SUP. Não houve diferença significativa para os níveis de IL-1, IL-4, IL-5, IL-10, IL-13, MIP-1 e TNF- (p>0,05), após tratamento, em ambas as terapias. Houve redução significativa de IL-6 (p=0,01), IL-12 (p=0,04) e MCP-1 (p=0,02) no grupo INT e de GCS-F nos grupos SUP (p=0,04) e INT (p=0,01). Os níveis de IL-2, IL-7, IL-8, IL-17, GM-CSF e IFN- não foram detectados. A terapia INT tem um efeito benéfico na redução dos níveis séricos de IL-6, IL-12 e MCP-1, na redução de PCS em sítios profundos e no ganho de inserção quando comparado à terapia supragengival em um período de 6 meses. / The objective of this study was to compare the serological and clinical effects of two periodontal therapies in individuals with type 2 diabetes (T2DM) and chronic periodontitis. 36 patients were analyzed, randomized into two groups: one group received intensive t of scaling and root planing (INT, n=18) and another received only supragingival scaling (SUP, n=18). The groups were evaluated for periodontal parameters and serum inflammatory markers before and after 6 months of periodontal treatment. The periodontal parameters assessed were: visible plaque (PI), gingival index (GI), suppuration (SUP), probing pocket depth (PPD) and clinical attachment level (CAL). Blood samples were obtained for analysis of inflammatory markers and glycated hemoglobin (HbA1c). The inflammatory markers evaluated were: interleukin (IL)- 1 , IL- 2, IL -4, IL -5, IL -6, IL -7 , IL-8 , IL-10 , IL-12 , IL-13 , IL -17, granulocyte colony-stimulated factor (G -CSF), colony stimulating factor granulocyte-macrophage (GM -CSF), interferon - (IFN - ), monocyte chemotactic protein-1 (MCP-1) , macrophage inflammatory protein-1 (MIP-1 ) and tumor necrosis factor (TNF- ) through a multiplex immunoassay (Bioplex). Both therapies resulted in improvement of almost all periodontal clinical parameters (p<0.05), with the exception of the NCI in SUP group. There was no significant difference for (IL )- 1 , IL- 4, IL -5, IL-10 , IL-13 , MIP- 1 and TNF- after treatment for both therapies (p>0.05). A significant reduction was observed in IL-6 (p=0.01), IL-12 (p=0.04) and MCP-1 (p=0.02) levels for INT group and in GCS- F levels for SUP (p=0.04) and INT (p=0.01) groups. The levels of IL-2, IL -7, IL-8 , IL-17, GM- CSF and IFN- were not detectable. The INT therapy has a beneficial effect in reducing serum levels of IL-6, IL-12 and MCP-1, in reducing PPD of deep sites and in attachment gain when compared to SUP therapy considering a period of 6 months.
|
230 |
Sobre a elevação persistente de troponina em pacientes diabéticos portadores de doença coronária obstrutiva estável / Troponin in diabetic patients with and without chronic coronary artery diseaseSegre, Carlos Alexandre Wainrober 24 November 2015 (has links)
Introdução: A determinação de troponinas I e T é considerado o padrão ouro para diagnóstico do infarto agudo do miocárdio. Novos métodos foram desenvolvidos possibilitando a determinação de troponinas em concentrações mínimas no plasma atualmente, abaixo de picogramas/mL. A pesquisa com estes novos marcadores mostrou concentrações detectáveis na população geral e também em pacientes com diferentes doenças associadas. Tem-se demonstrado correlação entre a elevação destes marcadores e mortalidade cardíaca e não cardíaca. Diabetes mellitus e doença arterial coronária são preditores conhecidos da elevação de troponinas. Não se sabe se há diferença entre as concentrações de troponinas em pacientes diabéticos com e sem doença arterial coronária. Objetivo: Quantificar as concentrações de troponinas em dois subgrupos de pacientes diabéticos: um grupo com doença arterial coronária e um segundo grupo controle - sem doença arterial coronária e comparar os resultados destes grupos. Métodos: Concentrações de troponinas foram determinadas em pacientes diabéticos: com e sem doença arterial coronária. Os pacientes foram pareados por idade e índice de massa corpórea. Ambos os grupos de pacientes tinham função ventricular avaliada como normal, pela ventriculografia no cateterismo ou por ecocardiografia transtorácica. Pacientes com fibrilação atrial e hipertrofia ventricular foram excluídos. As concentrações de BNP, nitrotirosina, mieloperoxidase e LDL oxidado também foram determinadas em ambos os grupos. Resultados: 95 pacientes participaram do estudo: 50 pacientes com doença arterial coronária (idade média=63,3 a, 58% masc) e 45 pacientes com artérias coronárias angiograficamente normais (idade média=61,4 a, 39,5% masc). As Concentrações de troponina foram significativamente mais elevadas em pacientes diabéticos com doença arterial coronária em relação aos pacientes do grupo controle (mediana=12,0 pg/mL (IQR=8,0-18,0) vs 7,0 pg/ mL (IQR =5,9-10,0)), respectivamente; p=0,0001. Com concentração de troponina maior que 9 pg/mL, a área sob a curva ROC para o diagnóstico de doença arterial coronária foi 0,712 com sensibilidade de 70% e especificidade de 66%. Concentrações plasmáticas de Peptídeo Natriurético Tipo B e variáveis de estresse oxidativo (mieloperoxidase, nitrotirosina e LDL oxidado) não foram diferentes entre os grupos. Análise multivariada para analisar associação com DAC mostrou que gênero (p=0,04), glicose sérica (p=0,03) e troponina I (p=0,01) tiveram significância estatística independente. Conclusão: Neste estudo a elevação de troponina correlacionou-se com a presença de doença arterial coronária em pacientes diabéticos, permitindo concluir que as troponinas podem ser usadas como biomarcadores nesta população de alto risco / Background: Cardiac-specific troponin detected with the new high-sensitivity assays can be chronically elevated in response to cardiovascular comorbidities and confer important prognostic information, in the absence of unstable coronary syndromes. Both diabetes mellitus and coronary artery disease are known predictors of troponin elevation. It is not known whether diabetic patients with coronary artery disease have different levels of troponin compared with diabetic patients with normal coronary arteries. To investigate this question, we determined the concentrations of troponin in two groups of diabetic patients: those with multivessel coronary artery disease and those with angiographically normal coronary arteries. Methods: We studied 95 diabetic patients and compared hsTnI in serum samples from 50 patients with coronary artery disease (mean age=63.7, 58% male) with 45 controls with angiographically normal coronary arteries. Brain natriuretic peptide and the oxidative stress biomarkers myeloperoxidase, nitrotyrosine, and oxidized LDL were also determined. Results: Diabetic patients with coronary artery disease had higher levels of troponin than did controls (median values, 12.0 pg/mL (IQR: 8,0-18,0) vs 7.0 pg/mL (IQR: 5,9-10,0), respectively; p=0.0001).The area under the ROC curve for the diagnosis of CAD was 0.712 with a sensitivity of 70% and a specificity of 66%. Plasma BNP levels and oxidative stress variables (myeloperoxidase, nitrotyrosine, and oxidized LDL) were not different between the two groups. In a multivariate analysis, gender (p=0.04), serum glucose (0.03) and hsTnI (p=0.01) had independent statistical significance. Conclusion: High-sensitivity troponin elevation is related to the presence of obstructive coronary artery disease in diabetic patients with multiple associated cardiovascular risk factors. High-sensitivity troponin may serve as a biomarker in this high-risk population
|
Page generated in 0.2197 seconds