Objective: Brugada Syndrome is an autosomal dominant congenital heart disease that is responsible for 20% of sudden deaths of patients with structurally normal hearts. The majority of mutations involve the cardiac sodium channel gene SCN5A and give rise to classical symptoms, which include an abnormal electrocardiogram with ST segment elevation and a predisposition to ventricular fibrillation. To date, the implantation of a cardioverter defibrillator is the only proven effective treatment of the disease. The ability to reprogram dermal fibroblasts to induced pluripotent stem (iPS) cells and to differentiate these into cardiomyocytes with the same genetic background provides a novel approach to studying inherited cardiac channelopathies with advantages over existing model systems. Whilst this technique has enormous potential to model inherited channelopathies, such as Brugada Syndrome, the derived cells have not been fully characterised and compared to foetal and adult cardiomyocytes. Methods: Dermal fibroblasts from a patient with Brugada syndrome (SCN5A; c.1100G > A - pARG367HIS) and an age- and sex-matched control were reprogrammed using episomal vectors. All newly derived iPS cell lines were fully characterised using immunocytochemistry, flow cytometry, real-time quantitative reverse transcription PCR and single nucleotide polymorphism analysis and were compared to established human embryonic stem (hES) cell and in-house derived healthy control iPS cell lines. The same control cell lines were used to compare the efficiencies of several cardiac differentiation media. Spontaneously contracting areas, derived from control as well as patient iPS cell lines, were disaggregated and single cardiomyocytes were compared to foetal and adult cardiomyocytes isolated from primary human tissue using immunocytochemistry, transmission electron microscopy, membrane visualisation, calcium imaging and electrophysiology. Results: Comparison of cardiac differentiation protocols using healthy control hES and iPS cell lines found that despite significant inter-line variability with regard to efficiency of cardiac formation guided differentiation protocols could be used to reliably and efficiently generate beating bodies. Spontaneous contraction was observed in stem cell-derived cardiomyocytes and human foetal cardiomyocytes. Pluripotent stem cell-derived cardiomyocytes stained for markers of the cardiac contractile apparatus such as α-actinin, cardiac troponin I and cardiac troponin T. They also expressed functional voltage-activated sodium channels and exhibited action potential triggered calcium-induced calcium release. Stem cell-derived cardiomyocytes showed organisation of myofibrils, ultrastructure and calcium handling more similar to foetal than adult cardiomyocytes. Brugada Syndrome patient-specific cardiomyocytes were structurally indistinguishable from healthy control iPS cell line-derived cardiomyocytes. Electrophysiological analysis of sodium current density confirmed a ~50% reduction in patient-derived compared to healthy control-derived cardiomyocytes. Conclusion: Although iPS cells give rise to a mixture of immature and more mature cardiomyocytes, they all express typical cardiac proteins and have functional cardiac sodium channels. Results illustrate the ability of patient-specific iPS cell technology to model the abnormal functional phenotype of an inherited channelopathy that is independent of structural abnormalities and that the relative immaturity of iPS cell-derived cardiomyocytes does not prevent their use as an accurate model system for channelopathies affecting the cardiac sodium channel Nav1.5. This iPS cell based model system for classical Brugada Syndrome allows for the first time to study the mutation in its native environment and holds promise for further studies to investigate disease mechanisms of known and unknown mutations and to develop new therapies.

The use of polymeric biomaterials in regenerative medicine and drug delivery is a continually growing practice. Alginic acid (alginate) is widely used in these fields because of its beneficial properties from an engineering and mechanical perspective. Still, alginate has not yet been fully investigated from a biological perspective. For disciplines that anticipate in vivo use of their devices, it is crucial to understand the biological interactions between the device and the host. In this project, the in vitro and in vivo immunological effects of alginate are examined in two model systems: one with a protein antigen and one with a xenogeneic cell antigen. The former system is used as a proof of principle study for alginate's immunological effect on simple protein-based systems, similar to those found in protein/drug deli very applications and certain types of vaccines. This model uses bovine serum albumin (BSA) as the protein antigen. The latter system is used to demonstrate alginate's effect on more complex antigens, such as whole cells. Thus, Chinese hamster ovary (CHO) cells are used as the as the cell antigen. This model represents a system that may be found in tissue engineering applications, where whole cells are delivered with a biomaterial scaffold. Antibody production from blood serum indicated that alginate solution has adjuvant abilities while alginate microspheres do not. Thus, alginate solution possesses great potential in the field of vaccines. In addition, in vivo alginate challenges were found to have effects on second-set responses of splenocytes to in vitro alginate and antigen challenges. Splenocytes from alginate-injected mice were overall equally or less responsive to in vitro challenges than splenocytes without previous alginate immunization. Therefore, alginate solution may also have immunosuppressive effects, although the results from this project merely speculate on this possibility. Still, this ability would be helpful in overcoming current transplantation problems as well as certain tissue engineering hurdles. / Thesis / Master of Science (MS)

Master of Science / Food Science Institute / J. Scott Smith / Heterocyclic amines (HCAs) are potentially carcinogenic and highly mutagenic byproducts of the Maillard browning reaction that form specifically in high temperature cooked meat products. Consumption of HCAs has been associated with various cancers including prostate, breast, colon, and pancreatic cancers and efforts have been made to understand formation and inhibition of these compounds. Chemical model systems are a preferred method to study the in vitro formation and inhibition of HCAs as the complex matrix effects found in meat are eliminated. Two black pepper extracts were evaluated for their efficacy on PhIP formation in model systems, but no significant results were observed. Secondly, four Maillard reaction variables were evaluated for their effect on formation of five HCAs (IQ, IQx, MeIQ, MeIQx, and 4,8-DiMeIQx) in chemical model systems with an effort to define an ideal model system. Precursor molar concentration (0.2/0.2, 0.4/0.4, 0.6/0.6, and 0.8/0.8 mmol), water percentage (0, 5, 10, and 15%), sugar type (fructose, galactose, glucose, and lactose), and sugar molar amount (quarter, half, equi, and double molar) were the four Maillard variables examined in the study. Additionally, four antioxidants (butylated hydroxyanisole (BHA), epigallocatechin gallate (EGCG), rosmarinic acid, and naringenin) were evaluated for their effect on HCA formation in chemical model systems. All four Maillard variables had a significant effect (p < 0.05) on the formation of HCAs in the model system, with an interaction effect occurring between water percentage and precursor concentration. The four antioxidants had no effect on the formation of HCAs in the model system. A model system containing 0.6/0.6/1.2 mmol of threonine, creatinine, and glucose, with 15% water was determined to be the best representative chemical model system for the formation of HCAs commonly formed in meats.

INTRODUÇÃO: A reação de Maillard ocorre em alimentos termicamente processados e também em sistemas biológicos, em que é chamada de glicação. Esta reação ocorre entre grupos carbonilas e grupamentos aminas e tem especial importância em alimentos, pois promovem alterações sensoriais importantes ao sabor, aroma, aparência e textura. Em sistemas biológicos, entretanto, podem acarretar mudanças em estruturas moleculares que favorecem o estresse oxidativo e participam da patogenia de complicações micro e macro vasculares características da diabetes, aterosclerose e doenças neurodegenativas. Os compostos carbonílicos ou produtos da reação de Maillard (PRMs) formados em alimentos contribuem para o aumento do pool endógeno de compostos carbonílicos. A utilização de substâncias ou alimentos que possam minimizar a formação destes compostos pode constituir-se em uma estratégia para minimizar a sua ingestão. OBJETIVO: Avaliar o efeito da adição de extrato etanólico de erva-mate verde na inibição da reação de Maillard em sistemas modelo alimento. METODOLOGIA: Foram elaborados modelos de biscoito e lácteos com e sem lipídios. Os teores de produtos da reação de Maillard [furosina (FUR), hidroximetilfurfural (HMF), carboximetilisina (CML) e produtos fluorescentes (IF)] foram avaliados. O extrato etanólico foi obtido por extração contínua a quente da erva-mate verde seca e caracterizado quanto aos teores de compostos fenólicos, cafeína e saponinas por cromatografia líquida. A intensidade de fluorescência dos sistemas foi avaliada por espectrofotometria, os teores de FUR e HMF foram analisados por cromatografia líquida de alta eficiência e de CML por ELISA. RESULTADOS: O extrato etanólico de erva-mate apresentou 155µg mg -1 de fenólicos totais, 76µg mg -1 de cafeína, 5µg mg de ácido ursólico e 3µg mg -1 de ácido oleanóico. A formação de HMF, FUR e IF nos sistemas modelo de biscoito não foi influenciada pela adição do extrato de erva-mate. O teor de CML do modelo com extrato do sistema de biscoito foi significativamente menor (p<0,05) em que os outros tratamentos com aquecimento, a porcentagem de inibição foi de 8%. A formação dos IF nos sistemas modelos lácteos adicionados de extrato foram significativamente menores (p<0,05) comparado aos modelos lácteos com aquecimento sem adição de extrato, a porcentagem de inibição foi de 30% para o modelo sem lipídeos e de 27% para o modelo com lipídeos. CONCLUSÃO: A adição do extrato etanólico da erva-mate verde foi efetiva em diminuir a reação de Maillard nos modelos de biscoito e lácteos. / INTRODUCTION: the Maillard reaction (MR) occurs in processed foods during heating, processing and storage and in biological systems, where it is called glycation. The MR is initiated by the condensation of amino groups of proteins with the carbonyl group of reducing sugars and has special importance in foods, because they promote sensory changes important to the flavor, aroma, color and texture. In biological systems, this reaction are involved in the progression of several diseases, such as diabetes, cardiovascular complications and neurodegenerative diseases. The Maillard reaction products contribute to increase the endogenous pool of carbonyl compounds. The use of substances or foods that can minimize the formation of these compounds may constitute a strategy to minimize your intake. OBJECTIVES: evaluate the effect of addition of the ethanolic extract of yerba mate in inhibition of the Maillard reaction in model food systems. METHODS: were developed cookies and milk models food systems. The content of Maillard reaction products [Furosine (FUR), hydroxymethylfurfural (HMF), carboxymethyllysine (CML) and fluorescent compounds (IF)] were evaluated. The yerba mate extract was obtained by hot continuous extraction and characterized for the levels of phenolic compounds and saponins by liquid chromatography. The contents of the fluorescent compounds (IF) was measured by spectrophotometric method, HMF and FUR were analyzed by high performance liquid chromatography and the levels of CML by ELISA. RESULTS: The yerba mate extract contained 155g mg -1 of total phenolics, 76g mg -1 of caffeine, 5g mg of ursolic acid and 3g mg -1 of oleanolic acid. The formation of HMF, FUR and IF in cookie systems was not influenced by the addition of the yerba mate extract. The CML content of the cookie model with yerba mate extract was significantly lower (p<0.05) than the other treatments with heating. The IF milk models added extract were significantly lower (p <0.05) than the IF milk models with heating without extract. CONCLUSION: The yerba mate extract reduced the formation of CML in the cookie system and inhibit the Maillard reaction in the intermediate stage in milk systems.

INTRODUÇÃO: A reação de Maillard ocorre em alimentos termicamente processados e também em sistemas biológicos, em que é chamada de glicação. Esta reação ocorre entre grupos carbonilas e grupamentos aminas e tem especial importância em alimentos, pois promovem alterações sensoriais importantes ao sabor, aroma, aparência e textura. Em sistemas biológicos, entretanto, podem acarretar mudanças em estruturas moleculares que favorecem o estresse oxidativo e participam da patogenia de complicações micro e macro vasculares características da diabetes, aterosclerose e doenças neurodegenativas. Os compostos carbonílicos ou produtos da reação de Maillard (PRMs) formados em alimentos contribuem para o aumento do pool endógeno de compostos carbonílicos. A utilização de substâncias ou alimentos que possam minimizar a formação destes compostos pode constituir-se em uma estratégia para minimizar a sua ingestão. OBJETIVO: Avaliar o efeito da adição de extrato etanólico de erva-mate verde na inibição da reação de Maillard em sistemas modelo alimento. METODOLOGIA: Foram elaborados modelos de biscoito e lácteos com e sem lipídios. Os teores de produtos da reação de Maillard [furosina (FUR), hidroximetilfurfural (HMF), carboximetilisina (CML) e produtos fluorescentes (IF)] foram avaliados. O extrato etanólico foi obtido por extração contínua a quente da erva-mate verde seca e caracterizado quanto aos teores de compostos fenólicos, cafeína e saponinas por cromatografia líquida. A intensidade de fluorescência dos sistemas foi avaliada por espectrofotometria, os teores de FUR e HMF foram analisados por cromatografia líquida de alta eficiência e de CML por ELISA. RESULTADOS: O extrato etanólico de erva-mate apresentou 155µg mg -1 de fenólicos totais, 76µg mg -1 de cafeína, 5µg mg de ácido ursólico e 3µg mg -1 de ácido oleanóico. A formação de HMF, FUR e IF nos sistemas modelo de biscoito não foi influenciada pela adição do extrato de erva-mate. O teor de CML do modelo com extrato do sistema de biscoito foi significativamente menor (p<0,05) em que os outros tratamentos com aquecimento, a porcentagem de inibição foi de 8%. A formação dos IF nos sistemas modelos lácteos adicionados de extrato foram significativamente menores (p<0,05) comparado aos modelos lácteos com aquecimento sem adição de extrato, a porcentagem de inibição foi de 30% para o modelo sem lipídeos e de 27% para o modelo com lipídeos. CONCLUSÃO: A adição do extrato etanólico da erva-mate verde foi efetiva em diminuir a reação de Maillard nos modelos de biscoito e lácteos. / INTRODUCTION: the Maillard reaction (MR) occurs in processed foods during heating, processing and storage and in biological systems, where it is called glycation. The MR is initiated by the condensation of amino groups of proteins with the carbonyl group of reducing sugars and has special importance in foods, because they promote sensory changes important to the flavor, aroma, color and texture. In biological systems, this reaction are involved in the progression of several diseases, such as diabetes, cardiovascular complications and neurodegenerative diseases. The Maillard reaction products contribute to increase the endogenous pool of carbonyl compounds. The use of substances or foods that can minimize the formation of these compounds may constitute a strategy to minimize your intake. OBJECTIVES: evaluate the effect of addition of the ethanolic extract of yerba mate in inhibition of the Maillard reaction in model food systems. METHODS: were developed cookies and milk models food systems. The content of Maillard reaction products [Furosine (FUR), hydroxymethylfurfural (HMF), carboxymethyllysine (CML) and fluorescent compounds (IF)] were evaluated. The yerba mate extract was obtained by hot continuous extraction and characterized for the levels of phenolic compounds and saponins by liquid chromatography. The contents of the fluorescent compounds (IF) was measured by spectrophotometric method, HMF and FUR were analyzed by high performance liquid chromatography and the levels of CML by ELISA. RESULTS: The yerba mate extract contained 155g mg -1 of total phenolics, 76g mg -1 of caffeine, 5g mg of ursolic acid and 3g mg -1 of oleanolic acid. The formation of HMF, FUR and IF in cookie systems was not influenced by the addition of the yerba mate extract. The CML content of the cookie model with yerba mate extract was significantly lower (p<0.05) than the other treatments with heating. The IF milk models added extract were significantly lower (p <0.05) than the IF milk models with heating without extract. CONCLUSION: The yerba mate extract reduced the formation of CML in the cookie system and inhibit the Maillard reaction in the intermediate stage in milk systems.

The effects of iron, temperature, and presence of botulinal spores or sodium ascorbate on depletion of nitrite level were determined in meat and model systems. Higher temperature and presence of botulinal spores definitely increased nitrite depletion in a meat system. Added hemoglobin also significantly increased nitrite depletion, while ferrous iron and ferric iron did not significantly decrease nitrite level in a meat system. High temperature and presence of sodium ascorbate increased nitrite depletion in a model system. Only ferrous iron significantly decreased nitrite level in the absence of ascorbate, while ferric iron, heme iron, and ferritin iron did not decrease nitrite level in the absence of ascorbate. Ferrous iron, ferric iron, and heme iron decreased nitrite level in the presence of ascorbate, while ferritin iron did not decrease nitrite level in a model system.

This paper provides an evolutionary perspective on financial systems based on complex systems theory. This perspective is used to organize the discussion about the convergence and non-convergence of financial systems. In recent years the discussion about the relative merits and the efficiency of market- and bank-based financial systems is subject to considerable academic and policy debate throughout the world. Bank- and market-based systems are found to give rise to different economic and corporate dynamics. Based on a notion of financial systems as configuration of complementary elements, it is suggested that the convergence of financial systems is best conceptualized as path dependent process of institutional change. This is illustrated with special reference to the recent developments of convergence of financial systems in Europe. The implication of the evolutionary perspective on financial systems is that neither theories using a simple evolutionary argument of survival of the fittest nor theories related to a institutional ossification perspective can provide much guidance for analyzing the transformations of financial systems. A multilevel institutional analysis which takes the interdependencies between national and firm-level institutions explicitly into account is required. (author's abstract) / Series: Working Papers Series "Growth and Employment in Europe: Sustainability and Competitiveness"

<p>Neurological disorders are a major public health concern due to prevalence, severity of symptoms, and impact on caregivers and economic losses. While genetic susceptibility likely has a role in most cases, exposure to toxicants can lead to neurotoxicity, including potentially developmental origins of adult disease or increased risk of disease onset. These exposures are not necessarily large, acute exposures, but could accumulate, with a chronic low-dose exposure, causing toxicity. This research focuses on the potential neurotoxicity of two classes of dietary toxins/toxicants, heterocyclic aromatic amines (HAAs) and per- and polyfluoroalkyl substances (PFAS). HAAs, such as PhIP, harmane, and harmine, are formed in charred or overcooked meat, coffee, tobacco, and other foods. PFAS are largely used in making household materials, but are found in small amounts in eggs and dairy products and largely in contaminated water. While these two classes are diverse in terms of structure, common neurotoxic targets and mechanisms often exist. Therefore, we tested the effects of these chemicals on cell viability and neurotoxicity. In the first aim, we aimed to elucidate the mechanism of toxicity of harmane and harmine, focusing on their ability to cause mitochondrial dysfunction. The second aim was to determine the effects of either harmane or PhIP on the nigrostriatal motor systems and motor function of rats and mice, respectively. The third aim determined the effects of PFAS on neurodevelopment of Northern leopard frogs, focusing on changes in neurotransmitter levels and accumulation in the brain. Harmane did not cause motor dysfunction, but potentially affected the nigro-striatal motor system in an age- or sex-dependent manner. PhIP had differential effects on dopamine levels over time and caused motor dysfunction after subchronic exposure in mice. Perfluorooctane sulfonate (PFOS) accumulated in the brains of frogs and PFAS caused changes in neurotransmitter levels that were dose- and time-dependent. Overall, this research shows that toxins/toxicants humans are exposed to over their whole lives through their diet and contaminated water can cause neurotoxicity, potentially leading to or increasing risk of disease states. </p>

Le cancer épithélial de l’ovaire (EOC) est le plus mortel des cancers gynécologiques. Cette maladie complexe progresse rapidement de façon difficilement décelable aux stades précoces. De plus, malgré une chirurgie cytoréductive et des traitements de chimiothérapie le taux de survie des patientes diagnostiquées aux stades avancées demeurt faible. Dans le but d’étudier l’EOC dans un contexte ex vivo, l’utilisation de modèles cellulaires est indispensable. Les lignées cellulaires d’EOC sont un outil pratique pour la recherche cependant, la façon dont l'expression des gènes est affectée en culture par comparaison à la tumeur d'origine n'est pas encore bien élucidée. Notre objectif était donc de développer et de caractériser de nouveaux modèles de culture in vitro qui réflèteront plus fidèlement la maladie in vivo. Nous avons tout d’abord utiliser des lignées cellulaires disponibles au laboratoire afin de mettre au point un modèle 3D de culture in vitro d’EOC. Des sphéroïdes ont été générés à l’aide de la méthode des gouttelettes inversées, une méthode pionnière pour la culture des cellules tumorales. Nous avons ensuite procédé à une analyse des profils d’expression afin de comparer le modèle sphéroïde au modèle de culture en monocouche et le modèle xénogreffe in vivo. Ainsi, nous avons identifié des gènes stratifiant les modèles tridimensionnels, tant in vivo qu’in vitro, du modèle 2D monocouche. Parmi les meilleurs candidats, nous avons sélectionné S100A6 pour une caractérisation ultérieure. L’expression de ce gène fût modulée afin d’étudier l’impact de son inhibition sur les paramètres de croissance des sphéroïdes. L’inhibition de ce gène a comme effet de réduire la motilité cellulaire mais seulement au niveau du modèle sphéroïde. Finalement, toujours dans l’optique de développer des modèles d’EOC les plus représentatifs de la maladie in vivo, nous avons réussi à développer des lignées cellulaires uniques dérivées de patientes atteintes d’EOC du type séreux, soit le plus commun des EOC. Jusque là, très peu de lignées cellulaires provenant de ce type de cancer et de patientes n’ayant pas reçu de chimiothérapie ont été produites. De plus, nous avons pour la première fois caractérise des lignées d’EOC de type séreux provenant à la fois de l’ascite et de la tumeur solide de la même patiente. / The epithelial ovarian cancer (EOC) is the most lethal of gynecological cancers. This complexe and heterogenous disease progresses rapidly and is almost asymptomatic in early stages. The survival rate of patients with late stage diagnosis remains low albeit cytoreductive surgery and chemotherapy. In order to study the EOC disease in an ex vivo context, the use of different cellular models is necessary. EOC cell lines derived from long-term passages of malignant ovarian cancers are useful tools for molecular and cellular research but it is not clear how culture conditions affect overall gene expression and oncogenic potential as compared to the original tumor. The main goal of this research was to develo and characterize new in vitro model systems that will recapitulate more closely some of the growth conditions encountered by tumor cells in vivo. In order to develop an in vitro tridimensional EOC spheroid model, we have used cell lines previously established in our laboratory. Spheroids were generated using the hanging droplet method, which was innovative for the culture of cancer cells. Comparative gene expression profile analysis of monolayer cultures, 3D spheroids and in vivo xenografts were performed and we have shown that the spheroid transcriptome more closely reflects expression patterns of the in vivo model compared to that of monolayer cultures. Among the best candidates, S100A6 gene over-expressed in the 3D models versus monolayer cultures was chosen for further analysis. To begin to address how S100A6 might affect EOC growth parameters, we have inhibited its expression in our in vitro models. The loss of S100A6 in the spheroid model results in an reduction of cellular migration, which seems to be in line with previous in vivo results published by other researchers. Always with the objective of developing the most relevant to the in vivo disease model systems, we have also succeeded in developing a unique EOC cell lines derived from patients with the most frequently diagnosed serous type of cancer. Very few cell lines derived from this type of cancers and from chemotherapy naïve patients are available. Moreover, we characterize for the first time EOC serous type cell lines derived from the ascites and the solid tumor of the same patient.

No description available.