Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-05-09T15:55:05Z No. of bitstreams: 1 eduardowalneidecastilhoalmeida.pdf: 11515838 bytes, checksum: 6a46c7d91fbd61ee3fd7a5b06c99915e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T14:27:31Z (GMT) No. of bitstreams: 1 eduardowalneidecastilhoalmeida.pdf: 11515838 bytes, checksum: 6a46c7d91fbd61ee3fd7a5b06c99915e (MD5) / Made available in DSpace on 2017-05-17T14:27:31Z (GMT). No. of bitstreams: 1 eduardowalneidecastilhoalmeida.pdf: 11515838 bytes, checksum: 6a46c7d91fbd61ee3fd7a5b06c99915e (MD5) Previous issue date: 2010-02-26 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / O presente trabalho se destina ao estudo de propriedades estruturais e termodinâmicas inerentes a triglicerídeos, ésteres de ácido graxo (EAG) e biodiesel por meio de metodologias teóricas e quimiométricas. Aliado a isso, o estudo do processo de transesterificação de triglicerídeos (TG) utilizando ciclodextrinas (CD) como potencias catalisadores também foi contemplado. Inicialmente, por meio de um planejamento fatorial Box-Behnken 34, foram avaliados os efeitos das variáveis envolvidas na simulação de dinâmica molecular (DM) de complexos de inclusão formados entre trilaurilglicerídeo (TLG – 12:0) e α-CD. Os resultados apontaram um protocolo de aquecimento de DM adequado para o tratamento de sistemas TG@n.α-CD com valores bem definidos para as variáveis envolvidas no processo: tempo de aquecimento (W), tempo de equilíbrio (E), passo da DM (S) e constante dielétrica (C). De posse deste protocolo, foram desenvolvidos estudos de DM contemplando complexos de inclusão formados entre modelos de TG utilizados para a síntese de biodiesel – trilaurilglicerídeo (TLG – 12:0), tripentadecanoilglicerídeo (TPDG – 15:0), trihexadecanoilglicerídeo (THDG – 16:0), triestearilglicerídeo (TESG – 18:0), trioleilglicerídeo (TOG – 18:1), trilinoleilglicerídeo (TLLG – 18:2) e trilinolenilglicerídeo (TLNG – 18:3) – e α-CD nativa e modificada (α-CD-NH2). Os resultados apontaram uma correlação entre a estabilidade dos complexos de inclusão TG@1.α-CD e o tamanho e o grau de saturação das cadeias triglicerídicas inclusas. Complexos de inclusão formados com TG de cadeias longas e insaturadas apresentaram menores valores de energia de complexação frente àqueles formados com outros tipos de cadeia triglicerídica. Em outra parte deste estudo, o potencial catalítico de CD na reação de transesterificação de TG também foi investigado por meio de cálculos de otimização de geometria e de frequências harmônicas vibracionais via DFT. Os resultados apontaram evidências termodinâmicas para tal proposta utilizando α-CD como catalisador. Além disso, espectros infravermelho e Raman teóricos foram determinados para algumas espécies de TG e EAG, visando a elucidação de possíveis métodos capazes de contribuir para as análises experimentais de biodiesel. Algumas distinções interessantes foram notadas entre o perfil do espectro de espécies saturadas e insaturadas e de misturas contendo impurezas inerentes ao processo de produção de biodiesel. / The present work aims the study of structural and thermodynamic properties for process involving triglycerides (TG), fatty acid esters (EAG) and biodiesel through theoretical and chemometrical methodologies. The study of the transesterification reaction of triglycerides (TG) using cyclodextrin (CD) as a potential catalyst were also carried out. Initially, through a Box-Behnken 34 factorial design, the effects of the variables involved in the molecular dynamics simulation (MD) of inclusion compounds formed between trilaurylglyceride (TLG – 12:0) and α-CD were evaluated. The results lead to an appropriated MD heating protocol for the treatment of TG@n.CD systems with specific values for the variables involved in the process: time of heating (W), equilibrium time (E), time step of the dynamics (S) and dielectric constant of the medium (C). Starting from the best protocol, MD studies were developed contemplating inclusion complexes formed between TG models used to the biodiesel synthesis – trilaurylglyceride (TLG – 12:0), tripentadecanoylglyceride (TPDG – 15:0), trihexadecanoylglyceride (THDG – 16:0), triestearylglyceride (TESG – 18:0), trioleylglyceride (TOG – 18:1), trilinoleylglyceride (TLLG – 18:2) e trilinolenylgliceride (TLNG – 18:3) – and native α-CD and modified cyclodextrin (α-CD-NH2). The results pointed out a correlation between the stability of the TG@1.α-CD inclusion compounds and the size and saturation degree of the triglyceridic included chain. The catalytic potential of CD in the transesterification reaction of TG was also investigated through geometry optimization and vibrational harmonic frequencies calculations via DFT. The results show thermodynamic evidences for such proposal using α-CD as catalyst. Besides, theoretical infrared and Raman spectra were determined for some TG and EAG species, looking for the elucidation of possible methods capable to contribute for the experimental analysis of biodiesel. Some interesting fingerprints were noticed in the spectrum of saturated and unsaturated species, allowing the characterization of complex mixtures obtained in the biodiesel production.

Orientador: Dora Maria Grassi Kassisse / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T14:23:50Z (GMT). No. of bitstreams: 1 Bellenzani_MarcelaPalomoPieroni_M.pdf: 6472856 bytes, checksum: e473a96a17b23ee1d9a456d9ac7a4602 (MD5) Previous issue date: 2012 / Resumo: A pandemia da obesidade é evidente no início do século XXI. O fator desencadeante mais relevante é a alimentação hipercalórica associada ao sedentarismo. Modelos de estudo em ratos para investigar as etapas que precedem o desenvolvimento desta doença são fundamentais para propor terapias de prevenção. No modelo de indução da dislipidemia pela dieta por quatro semanas, os ratos apresentam hipercolesterolemia, hipertrigliceridemia e hiperinsulinemia e com seis semanas de administração da dieta observa-se um aumento no peso dos panículos adiposos da região epididimal e peri-renal e sem alteração no depósito da região mesentérica. Assim sendo, objetivamos, nesta tese, analisar as vias metabólicas envolvidas no processo de metabolização da glicose e triacilgliceróis nos tecidos adiposo branco e hepático em ratos hiperlipidêmicos e para tal estudamos as vias lipogênica, lipolítica e neoglicogênica, pela quantificação da expressão gênica das enzimas chaves envolvidas nestes processos. A dislipidemia foi induzida pelo oferecimento de dieta hiperlipídica (grupo dieta, D) ao longo de quatro semanas a ratos jovens e a instalação do quadro foi verificada pelas análises plasmáticas ao final do tratamento e após jejum de 16h. Amostras de tecidos hepático e adiposo foram coletadas para análise histológica e quantificação da expressão gênica sendo estas analisadas por qRT-PCR. Observou-se que ratos que ingerem dieta hiperlipídica (+129+10,13 g) ganham peso de forma semelhante aos ratos controle (C: +148+8,8 g) mesmo ingerindo quantidade significativamente menor de dieta (C: 20,8+0,62 g vs D: 14,87+0,66 g). As análises histológicas ilustram aumento no teor de depósitos de lipídeos no tecido hepático. A expressão gênica no tecido hepático de ratos dieta foi aumentada significativamente para as enzimas lipoproteína lipase, piruvato desidrogenase quinase 4 e fosfofrutoquinase 1 e diminuição significativa na expressão de glicose 6-fosfatase sem alteração na quantificação da expressão de acetil-CoA carboxilase alpha, gliceroquinase, piruvato desidrogenase fosfatase 2. Em relação ao tecido adiposo observamos que a expressão das enzimas acetil-CoA carboxilase e piruvato desidrogenase fosfatase 2 não foi significativamente alterada em nenhum dos depósitos adiposos. A lipase hormônio-sensível não apresentou alterações no tecido adiposo epididimal, porém teve sua expressão significativamente aumentada nos tecidos mesentérico e peri-renal. A expressão da lipoproteína lipase por sua vez, não se alterou no panículo adiposo epididimal nem no panículo adiposo mesentérico estando diminuída no panículo adiposo peri-renal. E por fim, a piruvato desidrogenase quinase 4 também não apresentou alterações nos depósitos epididimal e mesentérico porém no peri-renal sua expressão encontrou-se aumentada. Estes resultados, em conjunto, indicam que a dieta administrada por 4 semanas, mesmo não apresentando todas as alterações observadas com 6 semanas, pode ser útil para os estudos iniciais do quadro de dislipidemia que antecedem as disfunções metabólicas / Abstract: The pandemic of obesity is evident in the twenty-first century. The most important and triggering factor is the high-calorie diet associated with physical inactivity. Study models in rats to investigate the steps that precede the development of this disease are essential to propose preventive therapies. In the model of induction of dyslipidemia by diet for four weeks, the mice exhibit hypercholesterolemia, hypertriglyceridemia, and hyperinsulinemia and there is an increase in weight of the panniculus region of epididymal and peri-renal depot and no change in the mesenteric region. Therefore, we aimed to analyze the metabolic pathways involved in the metabolism of glucose and triglycerides in white adipose tissue, and liver in hyperlipidemic rats and to study the ways that lipogenic, lipolytic and glyconeogenic for the quantification of gene expression of key enzymes involved in these processes. Dyslipidemia was induced by offering high-fat diet (diet group, D) over four weeks to young rats and onset of condition was verified by analysis at the end of the plasma treatment and after fasting for 16 hours. Samples of liver and adipose tissue were collected for histological analysis and quantification of gene expression and these were analyzed by qRT-PCR. It was observed that mice eat high-fat diet (+129 +10.13 g) gain weight similarly to control rats (C: +8.8 +148 g) even eating significantly less diet (C: 20.8 +0.62 g vs D: 14.87 +0.66 g). Histological analysis illustrate the content of lipid deposits in liver tissue. Gene expression in liver tissue of rats diet was significantly increased for the enzymes lipoprotein lipase, pyruvate dehydrogenase kinase 4 and 1 and Phosphofructokinase significant decrease in the expression of glucose 6-phosphatase no change in the quantification of the expression of acetyl-CoA carboxylase alpha, Gliceroquinase, pyruvate dehydrogenase phosphatase 2. In relation to the adipose tissue we observed that the expression of the enzyme acetyl-CoA carboxylase and pyruvate dehydrogenase phosphatase 2 was not significantly altered in any of the fatty deposits. The hormone-sensitive lipase showed no changes in epididymal adipose tissue but its expression was significantly increased in mesenteric tissue and peri-renal. Lipoprotein lipase, in turn, did not change in the mesenteric or epididymal being reduced in the peri-renal. And finally, the pyruvate dehydrogenase kinase 4 also showed no changes in epididymal and mesenteric but the peri-renal expression is increased. These results, together, indicate that the diet for 4 weeks, even not showing all changes observed within 6 weeks, can be useful for the initial studies of hyperlipidemia that precede the metabolic dysfunctions / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

Philosophiae Doctor - PhD / The production of biodiesel (methyl esters) from vegetable oils represents analternative means of producing liquid fuels from biomass, and one which is growing rapidly in commercial importance and relevance due to increase in petroleum prices and the environmental advantages the process offers. Commercially, biodiesel is produced from vegetable oils, as well as from waste cooking oils and animal fats. These oils are typically composed of C14-C20 fatty acid triglycerides. In order to produce a fuel that is suitable for use in diesel engines, these triglycerides are usually converted into the respective mono alkyl esters by base-catalyzed transesterification with short chain alcohol, usually methanol. In the first part of this study, the transesterification reactions of three different vegetable oils; sunflower (SFO), soybean (SBO) and waste cooking oil (WCO) with methanol was studied using potassium hydroxide as catalyst in a conventional batch process. The production of biodiesel from waste cooking oil was also studied via continuous operation systems (employing the use of low frequency ultrasonic technology and the jet loop reactor). The characterisation of the feedstock used and the methyl ester products were determined by different analytical techniques such as gas chromatography (GC), high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). The effects of different reaction parameters (catalyst amount, methanol to oil ratio, reaction temperature, reaction time) on methyl ester/FAME yield were studied and the optimum reaction conditions of the different process systems were determined. The optimum reaction conditions for production of methyl esters via the batch process with the fresh oil samples (SFO and SBO) were established as follows: a reaction time of 60 min at 60 ºC with a methanol: oil ratio of 6:1 and 1.0 KOH % wt/wt of oil; while the optimum reaction conditions for the used oil (WCO) was observed at a reaction time of 90 min at 60 ºC, methanol: oil ratio of 6:1 and 1.5% KOH wt/wt of oil. The optimum reaction conditions for the transesterification of the WCO via ultrasound technology applied in a continuous system in this study were: a reaction time of 30 min, 30 ºC, 6:1 methanol/oil ratio and a 0.75 wt% (KOH) catalyst concentration. The ultrasound assisted transesterification reactions performed at optimum conditions on the different oil samples led to higher yields of methyl esters (96.8, 98.32 and 97.65 % for WCO, SFO and SBO respectively) compared to methyl esters yields (90, 95 and 96 % for WCO, SFO and SBO respectively) obtained when using conventional batch procedures. A considerable increase in yields of the methyl esters in the ultrasound assisted reaction process were obtained at room temperature, in a remarkably short time span (completed in 30 min) and with a lower amount of catalyst (0.75 wt % KOH) while the results from the continuous jet loop process system showed even better results, at an optimum reaction condition of 25 min of reaction, a methanol: oil ratio of 4:1 and a catalyst amount of 0.5 wt%. This new jet loop process allowed an added advantage of intense agitation for an efficient separation and adequate purification of the methyl esters phase at a reduced time of 30 min. The use of homogeneous catalysts in conventional processes poses many disadvantages; heterogeneous catalysts on the other hand are attractive on the basis that their use could enable the biodiesel production to be more readily performed as a continuous process resulting in low production costs. Consequently, a solid base catalyst (KNO3/FA) prepared from fly ash (obtained from Arnot coal power station, South Africa) and a new zeolite, FA/Na-X synthesized from the same fly ash were used as solid base catalysts in the transesterification reactions in the conversion of a variety of oil feedstock with methanol to methyl esters. Since fly ash is a waste product generated from the combustion of coal for power generation, its utilization in this manner would allow for its beneficiation (as a catalytic support material and raw material for zeolite synthesis) in an environmentally friendly way aimed at making the transesterification process reasonably viable. Arnot fly ash (AFA) was loaded with potassium (using potassium nitrate as precursor) via a wet impregnation method while the synthesized zeolite FA/Na-X was ion exchanged with potassium (using potassium acetate as precursor) to obtain the KNO3/FA and FA/K-X catalysts respectively. Several analytical techniques were applied for characterization purposes. The results of the XRD and XRF showed that the AFA predominantly contained some mineral phases such as quartz, mullite, calcite and lime. The high concentration of CaO in AFA was apparent to be beneficial for the use of fresh fly ash as a support material in the heterogeneous catalysed transesterification reactions. XRD characterisation of KNO3/FA results indicated that the structure of KNO3/FA gradually changed with the increase in KNO3 loading. The catalyst function was retained until the loading of KNO3 was over 10 %. IR spectra showed that the KNO3 was decomposed to K2O on the fly ash support during preparation at a calcination temperature of 500 ºC. The CO2-TPD of the KNO3/FA catalysts showed that two basic catalytic sites were generated which were responsible for high catalytic abilities observed in the transesterification reactions of sunflower oil to methyl esters. On the other hand, XRD results for the as- received zeolite synthesized from AFA showed typical diffraction peaks of zeolite NaX. SEM images of the FA /NaX showed nano platelets unique morphology different from well known pyramidal octahedral shaped crystal formation of faujasite zeolites and the morphology of the FA /KX zeolite did not show any significant difference after ion exchange. The fly ash derived zeolite NaX (FA /NaX) exhibited a high surface area of 320 m2/g. The application of the KNO3/FA catalysts in the conversion reactions to produce methyl esters (biodiesel) via transesterification reactions revealed methyl ester yield of 87.5 % with 10 wt% KNO3 at optimum reaction conditions of methanol: oil ratio of 15:1, 5 h reaction time, catalyst amount of 15 g and reaction temperature 160 °C, while with the use of the zeolite FA/K-X catalyst, a FAME yield of 83.53 % was obtained for 8 h using the ion exchanged Arnot fly ash zeolite NaX catalyst (FA/KX) at reaction conditions of methanol: oil ratio of 6:1, catalyst amount of 3 % wt/wt of oil and reaction temperature of 65 ºC. Several studies have been carried out on the production of biodiesel using different heterogeneous catalysts but this study has been able to uniquely demonstrate the utilization of South African Class F AFA both as a catalyst support and as a raw material for zeolite synthesis; these catalyst materials subsequently applied sucessfully as solid base catalysts in the production of biodiesel. / South Africa

The heparan sulfate 6-O-sulfotransferase 3 (HS6ST3) gene is involved in heparan sulphate and heparin metabolism, and has been reported to be associated with diabetic retinopathy in type 2 diabetes. We hypothesized that HS6ST3 gene polymorphisms might play an important role in obesity and related phenotypes (such as triglycerides). We examined genetic associations of 117 single-nucleotide polymorphisms (SNPs) within the HS6ST3 gene with obesity and triglycerides using two Caucasian samples: the Marshfield sample (1442 obesity cases and 2122 controls), and the Health aging and body composition (Health ABC) sample (305 cases and 1336 controls). Logistic regression analysis of obesity as a binary trait and linear regression analysis of triglycerides as a continuous trait, adjusted for age and sex, were performed using PLINK. Single marker analysis showed that six SNPs in the Marshfield sample and one SNP in the Health ABC sample were associated with obesity (P < 0.05). SNP rs535812 revealed a stronger association with obesity in meta-analysis of these two samples (P = 0.0105). The T-A haplotype from rs878950 and rs9525149 revealed significant association with obesity in the Marshfield sample (P = 0.012). Moreover, nine SNPs showed associations with triglycerides in the Marshfield sample (P < 0.05) and the best signal was rs1927796 (P = 0.00858). In addition, rs7331762 showed a strong gene × gender interaction (P = 0.00956) for obesity while rs1927796 showed a strong gene × gender interaction (P = 0.000625) for triglycerides in the Marshfield sample. These findings contribute new insights into the pathogenesis of obesity and triglycerides and demonstrate the importance of gender differences in the aetiology.

The heparan sulfate 6-O-sulfotransferase 3 (HS6ST3) gene is involved in heparan sulphate and heparin metabolism, and has been reported to be associated with diabetic retinopathy in type 2 diabetes. We hypothesized that HS6ST3 gene polymorphisms might play an important role in obesity and related phenotypes (such as triglycerides). We examined genetic associations of 117 single-nucleotide polymorphisms (SNPs) within the HS6ST3 gene with obesity and triglycerides using two Caucasian samples: the Marshfield sample (1442 obesity cases and 2122 controls), and the Health aging and body composition (Health ABC) sample (305 cases and 1336 controls). Logistic regression analysis of obesity as a binary trait and linear regression analysis of triglycerides as a continuous trait, adjusted for age and sex, were performed using PLINK. Single marker analysis showed that six SNPs in the Marshfield sample and one SNP in the Health ABC sample were associated with obesity (P < 0.05). SNP rs535812 revealed a stronger association with obesity in meta-analysis of these two samples (P = 0.0105). The T-A haplotype from rs878950 and rs9525149 revealed significant association with obesity in the Marshfield sample (P = 0.012). Moreover, nine SNPs showed associations with triglycerides in the Marshfield sample (P < 0.05) and the best signal was rs1927796 (P = 0.00858). In addition, rs7331762 showed a strong gene × gender interaction (P = 0.00956) for obesity while rs1927796 showed a strong gene × gender interaction (P = 0.000625) for triglycerides in the Marshfield sample. These findings contribute new insights into the pathogenesis of obesity and triglycerides and demonstrate the importance of gender differences in the aetiology.

No description available.

No description available.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24880号 / 医博第5014号 / 新制||医||1068(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 長船 健二, 教授 江木 盛時, 教授 妹尾 浩 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Objective. Similar to obesity, lipodystrophy (LD) causes adipose tissue dysfunction and severe metabolic complications. Growth differentiation factor 15 (GDF15) belongs to the transforming growth factor β superfamily and is dysregulated in metabolic disease including obesity and diabetes mellitus. Circulating levels in LD and the impact of leptin treatment have not been investigated so far. Material and Methods. GDF15 serum levels were quantified in 60 LD patients without human immunodeficiency virus infection and 60 controls matched for age, gender, and body mass index. The impact of metreleptin treatment on circulating GDF15 was assessed in a subgroup of patients. GDF15 mRNA expression was determined in metabolic tissues of leptin-deficient lipodystrophic aP2-nSREBP1c-Tg mice, obese ob/ob mice, and control C57Bl6 mice. Results. Median GDF15 serum concentrations were significantly higher in LD patients (819 ng/L) as compared to the control group (415 ng/L) (p < 0.001). In multiple linear regression analysis, an independent and positive association remained between GDF15 on one hand and age, patient group, hemoglobin A1c, triglycerides, and C-reactive protein on the other hand. Moreover, there was an independent negative association between GFD15 and estimated glomerular filtration rate. Circulating GDF15 was not significantly affected by metreleptin treatment in LD patients. Gdf15 was upregulated in leptin-deficient lipodystrophic mice as compared to controls. Moreover, Gdf15 mRNA expression was downregulated by leptin treatment in lipodystrophic and obese animals. Conclusions. Serum concentrations of GDF15 are elevated in LD patients and independently associated with markers of metabolic dysfunction. Gdf15 expression is higher in lipodystrophic mice and downregulated by leptin treatment.

Objective. Similar to obesity, lipodystrophy (LD) causes adipose tissue dysfunction and severe metabolic complications. Growth differentiation factor 15 (GDF15) belongs to the transforming growth factor superfamily and is dysregulated in metabolic disease including obesity and diabetes mellitus. Circulating levels in LDand the impact of leptin treatment have not been investigated so far.Material and Methods. GDF15 serum levels were quantified in 60 LD patients without human immunodeficiency virus infection and 60 controlsmatched for age, gender, and bodymass index. The impact ofmetreleptin treatment on circulating GDF15 was assessed in a subgroup of patients. GDF15 mRNA expression was determined in metabolic tissues of leptin-deficient lipodystrophic aP2-nSREBP1c-Tg mice, obese ob/ob mice, and control C57Bl6 mice. Results. Median GDF15 serum concentrations were significantly higher in LD patients (819 ng/L) as compared to the control group (415 ng/L) (p < 0.001). In multiple linear regression analysis, an independent and positive association remained between GDF15 on one hand and age, patient group, hemoglobin A1c, triglycerides, and C-reactive protein on the other hand. Moreover, there was an independent negative association between GFD15 and estimated glomerular filtration rate. Circulating GDF15 was not significantly affected by metreleptin treatment in LD patients. Gdf15 was upregulated in leptin-deficient lipodystrophic mice as compared to controls. Moreover, Gdf15 mRNA expression was downregulated by leptin treatment in lipodystrophic and obese animals. Conclusions. Serum concentrations of GDF15 are elevated in LD patients and independently associated withmarkers of metabolic dysfunction. Gdf15 expression is higher in lipodystrophic mice and downregulated by leptin treatment.