As radiações ionizantes são provenientes tanto de fontes naturais como de fontes antropogênicas. A radioterapia emergiu como uma das terapias mais comuns no combate ao câncer. Irradiadores de Co-60 (aceleradores lineares de cobalto- 60) são usados para tratamento de tumores malignos rotineiramente em hospitais de todo o mundo. Exposições às radiações ionizantes podem induzir alterações nas macromoléculas celulares e afetar suas funções, pois causam radiólise da molécula de água gerando espécies reativas do oxigênio, que podem causar danos a praticamente todas as organelas e constituintes da célula, conhecidos como danos oxidativos, que podem culminar no estresse oxidativo. O estresse oxidativo é a situação na qual foi rompido o equilíbrio entre oxidantes e antioxidantes, com excessiva produção de espécies reativas, não acompanhada do aumento da capacidade antioxidante, inviabilizando assim, a neutralização das mesmas. O selênio é um micronutriente considerado antioxidante e antiinflamatório, que poderia prevenir o câncer. No sistema biológico o selênio existe na forma de selenoproteínas. Até o presente momento, 25 selenoproteinas humanas já foram identificadas, entre elas a enzima Glutationa peroxidase, uma enzima antioxidante. Leveduras têm a capacidade de incorporar diversos metais tais como ferro, cádmio, zinco e selênio, assim como todos os organismos biológicos. A levedura Saccharomyces cerevisiae, ao contrário das células de mamíferos é desprovida de selenoproteínas, sendo considerada como um modelo prático para estudos de toxicidade do selênio, sem qualquer interferência do metabolismo de selenoproteínas. Além disso, células de leveduras proliferam-se por meio de da fermentação, o equivalente microbiano da glicólise aeróbia em mamíferos que é o processo utilizado por tumores. Vários relatos mostram que os efeitos pró-oxidantes e tóxicos induzidos por compostos de selênio ocorrem em doses mais baixas em células malignas quando comparadas às células normais dando ao selênio um grande potencial terapêutico no tratamento do câncer. Nosso objetivo foi verificar se o selênio desempenha função radiossenbilizadora em células de levedura ao serem desafiadas com radiação ionizante (60Co) . Para isso foi avaliado se o selênio causa danos oxidativos para a célula e morte celular. Em seguida foi avaliado se ocorre diferença nos danos oxidativos após as células serem tratadas com selênio e irradiação gama. Nossos resultados demonstraram que o selênio exerce função radiossensibilizadora e tem papel oxidante nas células de levedura. / Ionizing radiations are from both natural sources such as from anthropogenic sources. Recently, radiotherapy has emerged as one of the most common therapies against cancer. Co-60 irradiators (cobalt-60 linear accelerators) are used to treat of malignant tumors routinely in hospitals around the world. Exposure to ionizing radiation can induce changes in cellular macromolecules and affect its functions, because they cause radiolysis of the water molecule generating reactive oxygen species, which can cause damage to virtually all organelles and cell components known as oxidative damage that can culminate in oxidative stress. Oxidative stress is a situation in which the balance between oxidants and antioxidants is broken resulting in excessive production of reactive species, it is not accompanied by the increase in antioxidant capacity, making it impossible to neutralize them. Selenium is a micronutrient considered as antioxidant, antiinflammatory, which could prevent cancer. Selenium in biological system exists as selenoproteins. Nowdays, 25 human selenoproteins have been identified, including glutathione peroxidase, an antioxidant enzyme. Yeasts have the ability to incorporate various metals such as iron, cadmium, zinc and selenium, as well as all biological organisms. The yeast Saccharomyces cerevisiae, unlike mammalian cells is devoid of selenoproteins, being considered as a practical model for studies on the toxicity of selenium, without any interference from the metabolism of selenoproteins. Moreover, yeast cells proliferate through the fermentation, the microbial equivalent of aerobic glycolysis in mammals and the process is also used by tumors. Several reports show that the pro-oxidante effects and induced toxic selenium compounds occur at lower doses and in malignant cells compared with benign cells. Therefore selenium giving a great therapeutic potential in cancer treatment .Our objective was to determine whether selenium is capable to sensitize yeasts cells when they are challenged with ionizing radiation produced by 60Co. For this, we assessed whether selenium causes oxidative damage to cell and cell death. After that, we assessed whether differences in the oxidative damage occurs after the cells be treated with selenium and gama irradiation. Our results showed that selenium has a rdiosensitizing function playing a oxidant role in yeast cell.

No presente trabalho, avaliou-se os efeitos individuais e combinados de nove enzimas comerciais sobre as propriedades reológicas de massa das farinhas de trigo, com o objetivo de identificar seus efeitos sinérgicos ou antagônicos e as suas concentrações ótimas, como alternativa para substituição de oxidantes químicos no tratamento de farinhas. α-Amilases de origem fúngica (AMY-F), bacteriana (AMY-B) e maltogênica (AMY-M), xilanases fúngica (XYL-F) e bacteriana (XYL-B), glucose oxidase (GOX), lacase (LAC), lipase (LIP) e transglutaminase (TG) foram testadas em dois tipos de farinha: uma farinha forte padrão (farinha A) e uma farinha fraca comum (farinha B). Inicialmente, as enzimas foram adicionadas individualmente na farinha onde, seus efeitos sobre Falling Number (FN), farinografia e alveografia, foram avaliados variando-se suas concentrações de 25 - 833 U.kg-1, a fim de se identificar as faixas de concentração ideais de cada uma delas. Identificou-se que as α-amilases afetaram principalmente as propriedades farinográficas, reduzindo a capacidade de absorção de água (WA) e tempo de estabilidade (ST) das massas. Para o ajuste de FN, AMY-B (150 U.kg-1) foi mais eficiente que AMY-F (583 U.kg-1) e AMY-M (583 U.kg-1). As xilanases melhoraram o valor de W (10-4 J) e razão P/L, sendo que em todos os testes XYL-B foi mais eficiente do que XYL-F. Na concentração de 25 U.kg-1, GOX e LAC melhoraram o ST, razão P/L e valor de W; no entanto, aumentaram o tempo de desenvolvimento (DT) das massas. LIP (150 U.kg-1) promoveu a melhora no W e DT, enquanto que TG não apresentou efeitos significativos na maioria dos parâmetros avaliados. A partir disso, os efeitos combinados das enzimas foram avaliados através de dois planejamentos experimentais sequenciais. Para farinha A, a combinação enzimática ótima foi AMY-B (166 U.kg-1), AMY-M (133 U.kg-1), XYL-B (150 U.kg-1), GOX (8 U. kg-1) e LIP (150 U.kg-1). Identificou-se um efeito sinérgico entre XYL-B e GOX na melhoria do W e razão P/L. Para a farinha B, a combinação enzimática ótima foi AMY-B (150 U.kg-1), LIP (150 U.kg-1), GOX (100 U.kg-1) e LAC (200 U.kg-1), sendo que GOX e LAC apresentaram um efeito cooperativo, quando usadas em concentrações opostas. As combinações enzimáticas foram mais eficientes do que a azodicarbonamida, cujo efeito, mesmo na concentração máxima (40 ppm) permitida pela legislação, não melhorou os parâmetros reológicos das massas. Foi demonstrado que é possível a substituição de oxidantes químicos por enzimas para o tratamento de farinhas, a fim de melhorar a reologia das massas, mesmo para uma farinha fraca, tornando-a adequada para panificação. / In the present work, it was evaluated the individual and combined effects of nine commercial enzymes on the rheological properties of dough wheat flour, aiming to identify synergistic and antagonist effects between the enzymes and their optimal concentrations as substitutes of chemical oxidants. Fungal (AMY-F), bacterial (AMY-B) and maltogenic (AMY-M) -amylases, fungal (XYL-F) and bacterial (XYL-B) xylanases, glucose oxidase (GOX), laccase (LAC), lipase (LIP) and transglutaminase (TG) were tested in two types of flour: standard strong flour (flour A) and common weak flour (flour B). Initially, Falling Number, farinography and alveography analysis were carried out varying the enzymes concentrations from 25 to 833 U.kg-1, to identify the ideal ranges of each of them to improve the rheological characteristics of dough wheat flour. It was identified that α-amylases affected mainly the farinographic properties, reducing the water absorption (WA) and stability time (ST). AMY-B was the most effective enzyme for setting the FN, requiring 150 U.kg-1, while for AMY-F and AMY-M it was necessary 583 U.kg-1. In all tests, XYL-B was more efficient than XYL-F, but both improved the W (10-4 J) value and P/L ratio. At 25 U.kg-1, GOX and LAC had important improves on the ST, P/L ratio and W value, however increased undesirably the development time (DT). LIP (150 U.kg 1) promoted the improvement in W value and DT, while TG had not significant effects on most of the evaluated parameters. After that, the combined effects of enzymes were evaluated through two sequential experimental designs. For flour A, the optimal combination of enzymes was AMY-B (166 U.kg-1), AMY-M (133 U.kg-1), XYL-B (150 U.kg-1), GOX (8 U.kg-1) and LIP (150 U.kg-1). It was identified a synergistic effect between XYL-B and GOX to improvement of W value (10-4 J) and the P/L ratio. For the flour B, the optimal combination of enzymes was AMY-B (150 U.kg-1), LIP (150 U.kg-1), GOX (100 U.kg-1) and LAC (200 U.kg-1). GOX and LAC presented a cooperative effect, when they were used at opposite concentrations. The enzymes mixtures were compared with chemical oxidant azodicarbonamide, and, even at the maximum concentration (40 ppm) allowed by Brazilian Health Surveillance Agency, the enzyme mixture was more effective. It was demonstrated that it is possible to perform the complete substitution of chemical oxidants by enzymes in order to adequate and improve the rheological parameters of dough wheat flours, even for a weak flour, making it suitable for bakery.

Fenn, Dickson. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 74-81). / Abstract also in Chinese. / Title Page --- p.i / Thesis Committee --- p.ii / Acknowledgement --- p.iii / Table of Contents --- p.v / List of Tables --- p.ix / List of Figures --- p.x / List of Abbreviations and Symbols --- p.xv / Abstract --- p.xvii / Chapter 1.Chapter One: --- Introduction --- p.1 / Chapter 1.1 --- Oxidation and Hyperoxidation of Guanine --- p.1 / Chapter 1.2. --- DNA Replication --- p.2 / Chapter 1.3 --- Mutagenesis --- p.3 / Chapter 1.4 --- Literature Survey on Spiroiminodihydantoin (Sp) --- p.4 / Chapter 1.5 --- Purpose of This Work --- p.5 / Chapter 1.6 --- DNA Structure --- p.6 / Chapter 1.6.1 --- Nomenclature --- p.6 / Chapter 1.6.2 --- Torsion Angles --- p.6 / Chapter 1.6.3 --- Sugar Pucker Conformation --- p.7 / Chapter 1.6.4 --- Secondary Structures of DNA --- p.8 / Chapter 2.Chapter Two: --- Materials and Methodology --- p.10 / Chapter 2.1 --- Sample Design --- p.10 / Chapter 2.2 --- Sample Preparation --- p.11 / Chapter 2.2.1 --- DNA Synthesis and Purification --- p.11 / Chapter 2.2.2 --- HPLC Separation --- p.11 / Chapter 2.2.3 --- NMR Samples Preparation --- p.12 / Chapter 2.3 --- NMR Analysis --- p.12 / Chapter 2.3.1 --- Resonance Assignment --- p.14 / Chapter 2.3.1.1 --- Proton --- p.14 / Chapter 2.3.1.2 --- Phosphorous --- p.16 / Chapter 2.3.2 --- Sugar Pucker Conformation --- p.17 / Chapter 2.3.3 --- Backbone Conformation --- p.18 / Chapter 2.4 --- UV Melting Analysis --- p.19 / Chapter 3.Chapter Three: --- "HPLC, NMR and UV Results" --- p.21 / Chapter 3.1 --- HPLC Separation of Sp Diastereoisomers --- p.21 / Chapter 3.2 --- NMR Resonance Assignments --- p.24 / Chapter 3.2.1 --- 5'-GG Sample --- p.24 / Chapter 3.2.2 --- 5'-G(oG) Sample --- p.26 / Chapter 3.2.3 --- 5'-G(Sp) Sample --- p.29 / Chapter 3.2.4 --- 5'-T(oG) Sample --- p.31 / Chapter 3.2.5 --- 5'-T(Sp) Sample --- p.34 / Chapter 3.3 --- Sugar Pucker Conformation --- p.38 / Chapter 3.4 --- Backbone Conformation --- p.41 / Chapter 3.5 --- UV Melting --- p.43 / Chapter 4.Chapter Four: --- Effect of Spiroiminodihydantoin and 7-hydro-8-oxoguanine on Primer-Template Structures --- p.44 / Chapter 4.1 --- Overview --- p.42 / Chapter 4.2 --- NMR Investigations of the Primer-Template Models --- p.45 / Chapter 4.2.1 --- Incorporation of a dCTP Opposite a 5'-GG Template --- p.45 / Chapter 4.2.2 --- Incorporation of a dCTP Opposite a 5'-G(oG) Template --- p.46 / Chapter 4.2.3 --- Incorporation of a dCTP Opposite a 5'-G(Sp) Template --- p.48 / Chapter 4.2.4 --- Incorporation of a dATP Opposite a 5'-T(oG) Template --- p.50 / Chapter 4.2.5 --- Incorporation of a dATP Opposite a 5'-T(Sp) Template --- p.51 / Chapter 4.3 --- Effect of Sp and oG on Primer-Template Structures --- p.52 / Chapter 4.3.1 --- Misaligned Structure with a Sp-Bulge --- p.52 / Chapter 4.3.2 --- C·oG Base Pair in 5'-G(oG) --- p.54 / Chapter 4.3.3 --- Biological Implications --- p.54 / Chapter 5. --- Chapter Five: Preliminary Structural Calculations on Primer- Template Structures --- p.56 / Chapter 5.1 --- Experimental Restraints Extraction --- p.56 / Chapter 5.2 --- Experimental Restraints Distribution --- p.58 / Chapter 5.3 --- Structural Calculations --- p.60 / Chapter 5.4 --- Structural Results --- p.62 / Chapter 5.4.1 --- 5'-GG --- p.63 / Chapter 5.4.2 --- 5'-G(oG) --- p.64 / Chapter 5.4.3 --- 5'-T(oG) --- p.65 / Chapter 5.4.4 --- 5'-T(SpR) with 5'-T(Spl) Restraints --- p.66 / Chapter 5.4.5 --- 5'-T(SpR) with 5'-T(Sp2) Restraints --- p.67 / Chapter 5.4.6 --- 5'-T(SpS) with 5'-T(Spl) Restraints --- p.68 / Chapter 5.4.7 --- 5'-T(SpS) with 5'-T(Sp2) Restraints --- p.69 / Chapter 5.6 --- Structural Analysis --- p.70 / Chapter 6. --- Chapter Six: Conclusions and Future Work --- p.72 / Appendix --- p.73 / References --- p.74

The SOD2 gene encodes the mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD), which converts superoxide (O2●-) to hydrogen peroxide (H2O2). Down-regulation of SOD2 has been reported in many cancer cells of diverse tissue origins, and forced over expression of this enzyme in carcinoma cells decreases their tumorigenicity. These findings suggest that SOD2 functions as an intiation or promotion tumor suppressor; however, it remains to be determined whether loss of SOD2 expression is sufficient for tumor formation since homozygous SOD2 knock-out mice die within weeks after birth. Additionally, due to the shortened lifespan of the constitutive SOD2 knock-out mouse limited studies have been performed in assessing the role of SOD2 in tissue-specific development in vivo. Using Cre-loxP genetics, we now have the capability to generate mice in which SOD2 may be knocked out in a cell type-specific manner and these mice can be used to query the effect of loss of SOD2 expression in tissue development, function, and oncogenesis. We primarily focused our studies on the hematopoietic system, but expanded our research to solid organs such as the liver and mammary gland as well. Our findings demonstrate that SOD2 does not act as a tumor suppressing enzyme in any of these unchallenged systems, and in fact the loss of SOD2 may act to delay tumor formation. T-cell specific SOD2 knock-out demonstrated significant immunodeficiency as illustrated by a decreased immune response to influenza challenge secondary to decreased T-cell populations. Furthermore, hematopoietic stem cell specific SOD2 knock-out showed a severe anemia in the red blood cell population due to increased mitochondrial superoxide. Additional analysis revealed the anemia to be a result of a porphyria due to the inactivation of the heme synthesis enzyme ferrochelatase. The observed phenotypes in all conditional hematological SOD2 knock-out models were rescued by the addition of mitochondrially targeted anti-oxidants. In conclusion, the tissue specific loss of SOD2 in various hematological organs appeared to demonstrate significant developmental and functional aberrations, but the role in tumor initiation appears to be limited if any. The data presented here also suggest the potential for novel anti-oxidant therapy in a variety of hematological diseases.

The plastic mulch films, which are mostly made from LDPE, are used in order to increase the yields and to prevent the weed growth by covering the top of the soil by leaves or straw in nature. After a period, the mulch films turn into unmanageable quantities of soiled plastic films, which cause an environmental problem. Using degradable mulch films for agricultural purposes can be a solution for the environmental problems caused by the plastic mulch films. In this study, to introduce biodegradability to mulch films, a natural biopolymer starch was used. Before blending, starch was transformed into thermoplastic starch in order to make the starch processable. The need, to provide adhesion and interaction between thermoplastic starch and LDPE, citric and stearic acid were considered as compatibilizers. To accelerate the degradation of the LDPE matrix, three pro-oxidants cobalt(II) acetylacetonate, iron(III) stearate and manganase(II) stearate were used. The films prepared were characterized by FTIR spectroscopy / their thermal and mechanical properties were analyzed and buried under soil. The films recovered from soil after 76 days were characterized by FTIR spectroscopy, their weight loss were measured and their thermal and mechanical properties were analyzed. Studies showed that the use of cobalt(II) acetylacetonate gave improved results in terms of the mechanical properties and thermal stabilities of the films. Additionally, it is observed that the use of citric acid as a compatibilizer improved the thermal stabilities of starch in the films. Lastly, it is observed that the mechanical properties of the films were affected by the interactions between compatibilizers and pro-oxidants.

Lung tumors secrete multiple factors that contribute to cachexia, a severe wasting syndrome that includes loss of muscle mass, weakness, and fatigue. 80% of advanced lung cancer patients experience cachexia, which cannot be reversed by nutritional interventions, diminishes response to and tolerance of cancer treatments, and increases morbidity and mortality. Despite a multitude of clinical trials, there are currently no approved treatments. This deficiency suggests that not all of the factors that contribute to cachexia have been identified. Cancer is frequently accompanied by an increase in cyclooxygenase-2 (COX-2), a hallmark of inflammation. Clinical trials for COX-2 inhibitors have resulted in restoration of muscle mass and decreased fatigue. Along with loss of myofibrillar proteins, cachexia also induces mitochondrial dysfunction, which contributes to fatigue. The amelioration of fatigue by COX-2 inhibition suggests possible alterations to mitochondrial function. We hypothesized that there were unidentified tumor-derived factors that contribute to cachectic wasting and fatigue. Treatment of C2C12 myotubes with Lewis lung cancer-conditioned media (LCM) resulted in increased COX-2 content, myosin loss, and mitochondrial dysfunction. Mass spectrometry revealed 158 confirmed proteins in LCM. We focused on extracellular 14-3-3 proteins because they bind and regulate over 200 known partners. We found that depletion of extracellular 14-3-3 proteins diminished myosin content. CD13, an aminopeptidase, is the proposed receptor for 14-3-3 proteins. Inhibiting aminopeptidases with Bestatin also reduced myosin content. LCM treatment decreased basal and ATP-related mitochondrial respiration, caused a transient rise in reactive oxygen species (ROS), and increased 4-Hydroxynonenal (4-HNE) in both cytosolic and mitochondrial fractions of cell lysates. COX-2 inhibition did not spare myosin content in LCM-treated myotubes, but did alter mitochondrial respiration and cytosolic oxidant levels. Our novel findings show that extracellular 14-3-3 proteins may act as previously unidentified myokines, signaling via aminopeptidases to help maintain muscle mass. We elucidated how LCM alters mitochondrial electron flow, and increases oxidative damage by ROS and 4-HNE. Although successful in clinical trials, COX-2 inhibitors do not appear to spare muscle mass by directly working on skeletal muscle, but did alter mitochondrial function.

Thesis (Ph.D. in Clinical Science) -- University of Colorado at Denver and Health Sciences Center, 2006. / Typescript. Includes bibliographical references (leaves 107-128). Free to UCDHSC affiliates. Online version available via ProQuest Digital Dissertations;

No presente trabalho, avaliou-se os efeitos individuais e combinados de nove enzimas comerciais sobre as propriedades reológicas de massa das farinhas de trigo, com o objetivo de identificar seus efeitos sinérgicos ou antagônicos e as suas concentrações ótimas, como alternativa para substituição de oxidantes químicos no tratamento de farinhas. α-Amilases de origem fúngica (AMY-F), bacteriana (AMY-B) e maltogênica (AMY-M), xilanases fúngica (XYL-F) e bacteriana (XYL-B), glucose oxidase (GOX), lacase (LAC), lipase (LIP) e transglutaminase (TG) foram testadas em dois tipos de farinha: uma farinha forte padrão (farinha A) e uma farinha fraca comum (farinha B). Inicialmente, as enzimas foram adicionadas individualmente na farinha onde, seus efeitos sobre Falling Number (FN), farinografia e alveografia, foram avaliados variando-se suas concentrações de 25 - 833 U.kg-1, a fim de se identificar as faixas de concentração ideais de cada uma delas. Identificou-se que as α-amilases afetaram principalmente as propriedades farinográficas, reduzindo a capacidade de absorção de água (WA) e tempo de estabilidade (ST) das massas. Para o ajuste de FN, AMY-B (150 U.kg-1) foi mais eficiente que AMY-F (583 U.kg-1) e AMY-M (583 U.kg-1). As xilanases melhoraram o valor de W (10-4 J) e razão P/L, sendo que em todos os testes XYL-B foi mais eficiente do que XYL-F. Na concentração de 25 U.kg-1, GOX e LAC melhoraram o ST, razão P/L e valor de W; no entanto, aumentaram o tempo de desenvolvimento (DT) das massas. LIP (150 U.kg-1) promoveu a melhora no W e DT, enquanto que TG não apresentou efeitos significativos na maioria dos parâmetros avaliados. A partir disso, os efeitos combinados das enzimas foram avaliados através de dois planejamentos experimentais sequenciais. Para farinha A, a combinação enzimática ótima foi AMY-B (166 U.kg-1), AMY-M (133 U.kg-1), XYL-B (150 U.kg-1), GOX (8 U. kg-1) e LIP (150 U.kg-1). Identificou-se um efeito sinérgico entre XYL-B e GOX na melhoria do W e razão P/L. Para a farinha B, a combinação enzimática ótima foi AMY-B (150 U.kg-1), LIP (150 U.kg-1), GOX (100 U.kg-1) e LAC (200 U.kg-1), sendo que GOX e LAC apresentaram um efeito cooperativo, quando usadas em concentrações opostas. As combinações enzimáticas foram mais eficientes do que a azodicarbonamida, cujo efeito, mesmo na concentração máxima (40 ppm) permitida pela legislação, não melhorou os parâmetros reológicos das massas. Foi demonstrado que é possível a substituição de oxidantes químicos por enzimas para o tratamento de farinhas, a fim de melhorar a reologia das massas, mesmo para uma farinha fraca, tornando-a adequada para panificação. / In the present work, it was evaluated the individual and combined effects of nine commercial enzymes on the rheological properties of dough wheat flour, aiming to identify synergistic and antagonist effects between the enzymes and their optimal concentrations as substitutes of chemical oxidants. Fungal (AMY-F), bacterial (AMY-B) and maltogenic (AMY-M) -amylases, fungal (XYL-F) and bacterial (XYL-B) xylanases, glucose oxidase (GOX), laccase (LAC), lipase (LIP) and transglutaminase (TG) were tested in two types of flour: standard strong flour (flour A) and common weak flour (flour B). Initially, Falling Number, farinography and alveography analysis were carried out varying the enzymes concentrations from 25 to 833 U.kg-1, to identify the ideal ranges of each of them to improve the rheological characteristics of dough wheat flour. It was identified that α-amylases affected mainly the farinographic properties, reducing the water absorption (WA) and stability time (ST). AMY-B was the most effective enzyme for setting the FN, requiring 150 U.kg-1, while for AMY-F and AMY-M it was necessary 583 U.kg-1. In all tests, XYL-B was more efficient than XYL-F, but both improved the W (10-4 J) value and P/L ratio. At 25 U.kg-1, GOX and LAC had important improves on the ST, P/L ratio and W value, however increased undesirably the development time (DT). LIP (150 U.kg 1) promoted the improvement in W value and DT, while TG had not significant effects on most of the evaluated parameters. After that, the combined effects of enzymes were evaluated through two sequential experimental designs. For flour A, the optimal combination of enzymes was AMY-B (166 U.kg-1), AMY-M (133 U.kg-1), XYL-B (150 U.kg-1), GOX (8 U.kg-1) and LIP (150 U.kg-1). It was identified a synergistic effect between XYL-B and GOX to improvement of W value (10-4 J) and the P/L ratio. For the flour B, the optimal combination of enzymes was AMY-B (150 U.kg-1), LIP (150 U.kg-1), GOX (100 U.kg-1) and LAC (200 U.kg-1). GOX and LAC presented a cooperative effect, when they were used at opposite concentrations. The enzymes mixtures were compared with chemical oxidant azodicarbonamide, and, even at the maximum concentration (40 ppm) allowed by Brazilian Health Surveillance Agency, the enzyme mixture was more effective. It was demonstrated that it is possible to perform the complete substitution of chemical oxidants by enzymes in order to adequate and improve the rheological parameters of dough wheat flours, even for a weak flour, making it suitable for bakery.

Submitted by DANIEL JOSÉ HOFFMANN null (danielhoffmann@veterinario.med.br) on 2017-08-09T20:35:31Z No. of bitstreams: 1 ASSOCIAÇÃO ENTRE A HIPERLEPTINEMIA E O ESTRESSE OXIDATIVO SISTÊMICO EM CÃES OBESOS (Daniel José Hoffmann).pdf: 1191810 bytes, checksum: f7623146140f3767e6c70e577034698d (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-08-11T19:09:17Z (GMT) No. of bitstreams: 1 hoffmann_dj_me_araca.pdf: 1191810 bytes, checksum: f7623146140f3767e6c70e577034698d (MD5) / Made available in DSpace on 2017-08-11T19:09:17Z (GMT). No. of bitstreams: 1 hoffmann_dj_me_araca.pdf: 1191810 bytes, checksum: f7623146140f3767e6c70e577034698d (MD5) Previous issue date: 2017-08-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A obesidade é um distúrbio nutricional frequente em cães, com prevalência de 30 a 50%, e representa um grande fator de risco para o desenvolvimento de uma série de doenças. A relação entre estresse oxidativo e obesidade em humanos é bem definida, entretanto em cães não está bem estabelecida. Foi realizada uma revisão bibliográfica sobre estresse oxidativo na obesidade canina, utilizando dois bancos de dados (Portal CAPES e PubMed), com fim de investigar a interferência do grau de obesidade no desenvolvimento do estresse oxidativo. Foi realizado um estudo observacional transversal com controle para confirmar a hipótese de que o grau de obesidade está correlacionado ao estresse oxidativo sistêmico. Para tal foram selecionados 121 cães, os quais foram distribuídos em grupos conforme o escore de condição corporal (ECC), controle (n=39), sobrepeso (n=38) e obeso (n=44). De todos os cães foram mensurados marcadores de obesidade (ECC e leptina) e marcadores de estresse oxidativo (Capacidade antioxidante total (TAC), Concentração oxidante total (TOC), Peroxidação lipídica (TBARS), Ácido úrico, Albumina, Gama Glutamil Transferase (GGT) e Índice de estresse oxidativo (IEO)). Os cães obesos apresentaram concentrações de leptina plasmática e indicadores de estresse oxidativo superiores aos demais grupos. Os valores intermediários de leptinemia e dos marcadores plasmáticos de estresse oxidativo sistêmico caracterizaram os cães com sobrepeso. Foi possível comprovar que a hiperleptinemia da obesidade está correlacionada com o estresse oxidativo sistêmico. / Obesity is a common nutritional disorder in dogs, with prevalence of 30 to 50%, and represents a major risk factor for the development of a number of diseases. The relationship between oxidative stress and obesity in humans is well defined, however in dogs is not well established. A literature review was performed on oxidative stress in canine obesity, using two databases (Portal CAPES and PubMed), to Investigate the interference of obesity degree in the development of oxidative stress. A crosssectional study was carried out with control to confirm the hypothesis that the degree of obesity is correlated to the oxidative stress. For such 121 dogs were selected, which were distributed in groups according to body condition score (ECC), control (n = 39), overweight (n = 38) and obese (n = 44). All the dogs were measured obesity markers (ECC and leptin) and markers of oxidative stress (Total Antioxidant Capacity (TAC), Total Oxidant Concentration (TOC), lipid peroxidation (TBARS), uric Acid, albumin, Gamma Glutamyl Transferase (GGT) and Oxidative Stress Index (IEO)). Obese dogs showed plasma leptin concentrations and oxidative stress indicators higher than the other groups. The intermediary values of leptin and the systemic oxidative stress plasmatic markers characterized the overweight dogs It was possible to prove that obesity hyperleptinemia is correlated with systemic oxidative stress. / FAPESP: 2014/20662-0

No presente trabalho, avaliou-se os efeitos individuais e combinados de nove enzimas comerciais sobre as propriedades reológicas de massa das farinhas de trigo, com o objetivo de identificar seus efeitos sinérgicos ou antagônicos e as suas concentrações ótimas, como alternativa para substituição de oxidantes químicos no tratamento de farinhas. α-Amilases de origem fúngica (AMY-F), bacteriana (AMY-B) e maltogênica (AMY-M), xilanases fúngica (XYL-F) e bacteriana (XYL-B), glucose oxidase (GOX), lacase (LAC), lipase (LIP) e transglutaminase (TG) foram testadas em dois tipos de farinha: uma farinha forte padrão (farinha A) e uma farinha fraca comum (farinha B). Inicialmente, as enzimas foram adicionadas individualmente na farinha onde, seus efeitos sobre Falling Number (FN), farinografia e alveografia, foram avaliados variando-se suas concentrações de 25 - 833 U.kg-1, a fim de se identificar as faixas de concentração ideais de cada uma delas. Identificou-se que as α-amilases afetaram principalmente as propriedades farinográficas, reduzindo a capacidade de absorção de água (WA) e tempo de estabilidade (ST) das massas. Para o ajuste de FN, AMY-B (150 U.kg-1) foi mais eficiente que AMY-F (583 U.kg-1) e AMY-M (583 U.kg-1). As xilanases melhoraram o valor de W (10-4 J) e razão P/L, sendo que em todos os testes XYL-B foi mais eficiente do que XYL-F. Na concentração de 25 U.kg-1, GOX e LAC melhoraram o ST, razão P/L e valor de W; no entanto, aumentaram o tempo de desenvolvimento (DT) das massas. LIP (150 U.kg-1) promoveu a melhora no W e DT, enquanto que TG não apresentou efeitos significativos na maioria dos parâmetros avaliados. A partir disso, os efeitos combinados das enzimas foram avaliados através de dois planejamentos experimentais sequenciais. Para farinha A, a combinação enzimática ótima foi AMY-B (166 U.kg-1), AMY-M (133 U.kg-1), XYL-B (150 U.kg-1), GOX (8 U. kg-1) e LIP (150 U.kg-1). Identificou-se um efeito sinérgico entre XYL-B e GOX na melhoria do W e razão P/L. Para a farinha B, a combinação enzimática ótima foi AMY-B (150 U.kg-1), LIP (150 U.kg-1), GOX (100 U.kg-1) e LAC (200 U.kg-1), sendo que GOX e LAC apresentaram um efeito cooperativo, quando usadas em concentrações opostas. As combinações enzimáticas foram mais eficientes do que a azodicarbonamida, cujo efeito, mesmo na concentração máxima (40 ppm) permitida pela legislação, não melhorou os parâmetros reológicos das massas. Foi demonstrado que é possível a substituição de oxidantes químicos por enzimas para o tratamento de farinhas, a fim de melhorar a reologia das massas, mesmo para uma farinha fraca, tornando-a adequada para panificação. / In the present work, it was evaluated the individual and combined effects of nine commercial enzymes on the rheological properties of dough wheat flour, aiming to identify synergistic and antagonist effects between the enzymes and their optimal concentrations as substitutes of chemical oxidants. Fungal (AMY-F), bacterial (AMY-B) and maltogenic (AMY-M) -amylases, fungal (XYL-F) and bacterial (XYL-B) xylanases, glucose oxidase (GOX), laccase (LAC), lipase (LIP) and transglutaminase (TG) were tested in two types of flour: standard strong flour (flour A) and common weak flour (flour B). Initially, Falling Number, farinography and alveography analysis were carried out varying the enzymes concentrations from 25 to 833 U.kg-1, to identify the ideal ranges of each of them to improve the rheological characteristics of dough wheat flour. It was identified that α-amylases affected mainly the farinographic properties, reducing the water absorption (WA) and stability time (ST). AMY-B was the most effective enzyme for setting the FN, requiring 150 U.kg-1, while for AMY-F and AMY-M it was necessary 583 U.kg-1. In all tests, XYL-B was more efficient than XYL-F, but both improved the W (10-4 J) value and P/L ratio. At 25 U.kg-1, GOX and LAC had important improves on the ST, P/L ratio and W value, however increased undesirably the development time (DT). LIP (150 U.kg 1) promoted the improvement in W value and DT, while TG had not significant effects on most of the evaluated parameters. After that, the combined effects of enzymes were evaluated through two sequential experimental designs. For flour A, the optimal combination of enzymes was AMY-B (166 U.kg-1), AMY-M (133 U.kg-1), XYL-B (150 U.kg-1), GOX (8 U.kg-1) and LIP (150 U.kg-1). It was identified a synergistic effect between XYL-B and GOX to improvement of W value (10-4 J) and the P/L ratio. For the flour B, the optimal combination of enzymes was AMY-B (150 U.kg-1), LIP (150 U.kg-1), GOX (100 U.kg-1) and LAC (200 U.kg-1). GOX and LAC presented a cooperative effect, when they were used at opposite concentrations. The enzymes mixtures were compared with chemical oxidant azodicarbonamide, and, even at the maximum concentration (40 ppm) allowed by Brazilian Health Surveillance Agency, the enzyme mixture was more effective. It was demonstrated that it is possible to perform the complete substitution of chemical oxidants by enzymes in order to adequate and improve the rheological parameters of dough wheat flours, even for a weak flour, making it suitable for bakery.