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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Adsorption of Biomacromolecules onto Polysaccharide Surfaces

Zhang, Xiao 02 October 2014 (has links)
Plant cell wall polysaccharides are abundant natural polymers making them potential sources for sustainable and biodegradable materials. Interfacial behavior, including adsorption and enzymatic degradation, of several plant cell wall polysaccharides and their derivatives were studied with a quartz crystal microbalance with dissipation monitoring (QCM-D), surface plasmon resonance (SPR) and atomic force microscopy (AFM). Xyloglucan adsorption isotherms were obtained to probe how cellulose-hemicellulose interactions were affected by the type of cellulose substrate and molar mass of xyloglucan. Xyloglucan as small as a heptasaccharide still adsorbed irreversibly onto cellulose. Carboxymethyl cellulose (CMC) adsorption onto cellulose and viscoelastic properties and water contents of the adsorbed CMC layers were obtained from a combination of QCM-D and SPR data. The CMC samples formed hydrated and viscoelastic layers compared to the relatively rigid xyloglucan layer. Pectin model surfaces were prepared by pectin adsorption from citric phosphate buffer onto gold substrates. These pectin model surfaces were used for subsequent interaction studies with xyloglucan and enzymatic degradation behavior. There is a strong correlation between the degree of esterification (DE) and film resistance to degradation with the high DE being the most susceptible to degradation. The adsorption of two mixed linkage glucans (MLG), barley and lichen MLG, onto regenerated cellulose (RC) surfaces in the absence and presence of other matrix polysaccharides was studied. Viscoelastic properties of the resulting layer were compared as a function of the proprotion of '-(1''3) linkages with lichen MLG forming softer gel-like layers on RC. The lichen MLG layers were further used for enzymatic degradation studies with respect to enzyme concentration, temperature, pH and ionic strength. These studies show that polymer adsorption is a promising strategy to modify material surfaces and provides fundamental understanding of interactions and biodegradation of cell wall polysaccharides at solid/liquid interfaces. / Ph. D.
52

Efeito genoprotetor in vitro de β-glucanas sobre linfócitos de frangos (Gallus gallus domesticus) expostos à aflatoxina B1 / In vitro genoprotective effect of β-glucan on broiler chicken (Gallus gallus domesticus) lymphocytes exposed to aflatoxin B1

Zimmermann, Carine Eloise Prestes 29 August 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aflatoxin B1 (AFB1) is one of the main mycotoxins that can be identified in foods, and has relevance for agricultural economics and public health because of its immunotoxic properties. A functional immune system is a basic requirement for a healthy life in modern animal production. The interaction involving nutrition and immunity is a strategic factor to obtain a high quality performance in the poultry industry. Immunomodulators such as β-glucans have an immunostimulating activity, which enables the host ability to resist opportunistic infections. To contribute to the elucidation of the mechanism of action of β-glucans in broiler chicken lymphocytes, the effects of the concentrations of 0.1, 1 and 10% of β-glucans derived from Saccharomyces cerevisiae were investigated in lymphocytes exposed to increasing concentrations of AFB1 (0, 0.1, 1, 10, 20 μg/ml). Lymphocytes were separated by Ficoll-Histopaque density and cultured in 96 well-plates containing AFB1 and/or β-glucans in a 5% CO2 atmosphere at 39°C. MTT, PicoGreen® and 2'-7'-dichlorofluorescein diacetate cytotoxicity tests were evaluated at 24, 48 and 72 h of incubation. The comet assay to elucidate the DNA damage was also performed. The percentage of viable cells decreased in the presence of 10 μg/ml AFB1 at 48 h (p < 0.05) and 10 and 20 μg/ml AFB1 at 72 h (p < 0.001 and p < 0.01, respectively), when compared to the control group (0 μg/ml). Furthermore, an increase in cell-free DNA in AFB1 concentrations > 1 μg/ml (p < 0.001) and the generation of ROS at 24 h were also observed. DNA damage increased approximately 2.3 fold in lymphocytes exposed to 20 μg/ml of AFB1 when compared to the control group. Conversely, β-glucans showed cytoprotective effects (p < 0.001), and the concentration of 1% reverted the AFB1-induced lymphocyte damage. β-glucans at 10% significantly increased (p < 0.001) the formation of reactive oxygen species (ROS), potentiating the AFB1-induced ROS formation. In conclusion, this study showed that AFB1 and β-glucans exert influence on lymphocyte oxidative metabolism and have dose-dependent potentiating effects. The results also showed genoprotective in vitro effect of β-glucans in poultry lymphocytes exposed to AFB1, being the concentration of 1% β-glucans able to maintain DNA integrity. / A aflatoxina B1 (AFB1) é uma das principais micotoxinas que podem ser identificadas em alimentos, possuindo relevância agroeconômica e para a saúde pública, por ser considerada imunotóxica. Um sistema imune funcional é um requisito básico para uma vida saudável na produção moderna de animais. A interação envolvendo nutrição e imunidade é um fator estratégico para obter um bom desempenho em frangos de corte. Devido as suas atividades imunomodulatórias, substâncias como as β-glucanas proporcionam ao hospedeiro uma maior capacidade de resistir a infecções oportunistas. Para melhor compreender o mecanismo de ação das β-glucanas, sobre os linfócitos de frangos de corte, investigou-se os efeitos das concentrações de 0.1, 1 e 10% de β-glucanas derivadas do fungo Saccharomyces cerevisiae em linfócitos expostos a crescentes concentrações de AFB1 (0, 0.1, 1, 10, 20 μg/ml). Os linfócitos foram separados através do reagente de densidade Ficoll-Histopaque e cultivados em placas de 96 poços, contendo as concentrações de AFB1 e/ou β-glucanas em atmosfera de 5% de CO2 a 39°C durante 24, 48 e 72 h. A citotoxicidade celular foi avaliada através dos testes MTT e PicoGreen®, e a formação de espécies reativas de oxigênio (EROS) através do ensaio 2′-7′- diacetato diclorofluoresceína. Também foi utilizado o teste cometa para elucidar os danos ao DNA. A viabilidade celular reduziu na presença de 10 μg/ml de AFB1 em 48 h (p < 0.05) e em 10 and 20 μg/ml de AFB1 (p < 0.01 e p < 0.001, respectivamente) em 72 h quando comparada ao grupo controle. Além disso, as concentrações de AFB1 > 1 μg/ml aumentaram significativamente (p < 0.001) a liberação de fita dupla de DNA (dsDNA) e a produção de EROS em 24 h. Os danos causados ao DNA foram confirmados através do momento cauda do cometa e aumentaram cerca de 2,3 vezes em linfócitos expostos a 20 μg/ml de AFB1 quando comparados ao grupo controle. Por outro lado, as β-glucanas exerceram efeitos citoprotetores (p < 0.001), sendo que a concentração de 1% foi capaz de reverter os danos genotóxicos causados pela ação da AFB1. Já a concentração de 10% de β-glucanas aumentou significativamente (p < 0.001) a formação de EROS, potencializando a ação da AFB1. Em conclusão, este estudou evidenciou que a AFB1 e as β-glucanas exercem influência sobre o metabolismo oxidativo dos linfócitos e possui efeito potencializador dose-dependente. Os resultados também evidenciaram o efeito genoprotetor in vitro de β-glucanas em linfócitos de frangos expostos a AFB1, sendo a concentração de β-glucanas a 1% capaz de manter a integridade do DNA.
53

Stanovení beta-glukanů a pentosanů v surovinách pro výrobu piva a v pivu / Determination of beta-glucans and pentosans in raw materials for production of beer and in beer

Piškulová, Lenka January 2017 (has links)
The content of beta-glucans and arabinoxylans in barley grain, malt and wort was monitored. The varieties of barley were Pionier, Libuše, Manta, Tango, KWS Amadora, Kampa, KWS Irina, Francin, Odyssey, Overture, Vendela, Petrus, Laudis 550, Sunshine, Kangoo, Xanadu, Sebastian, Bojos and Malz. These varieties were grown on three different habitats (Uherský Ostroh, Věrovany and Vysoká u Příbramě). The content of beta-glucans and arabinoxylans was also analysed in five different types of beer. In brewing and malting industry the content of beta-glucans and arabinoxylans is mainly monitored because of their negative influence on decanting of wort and filtration of beer. These substances can contribute to turbidity and precipitation in beer and thus negatively effect the stability of beer. The content of beta-glucans in barley grain, malt, wort and beer was determined by FIA method and the content of arabinoxylans was determined in barley grain, wort and beer by Douglas method. The highest content of beta-glucans in barley grain was found in 14/19 varieties at Uherský Ostroh, where the amount of beta-glucan content was in the range of 3,65-5,60 %. The highest beta-glucan content in malt was found in 17/19 varieties at Vysoká u Příbramě, where the beta-glucan content was between 0,15-0,79 % and the highest content of beta-glucans in wort was found in 16/19 varieties also at Vysoká u Příbramě. There was the beta-content in the range of 22-184 mg/l. The results of content of arabinoxylans in barley grain and wort were more balanced. The highest content of arabinoxylans in barley grain was found in 10/19 varieties at Věrovany. The content of arabinoxylans at this habitat was in the range of 3,04-4,56 %. The highest content of arabinoxylans in wort was determined in 8/19 varieties at Uherský Ostroh. The content of arabinoxylans at this habitat was in the range of 542-1040 mg/l. The highest content of beta-glucans in samples of beer was determined in a sample of light lager (207 mg/l) and the highest content of arabinoxylans was found in a samle of wheat lager (1465 mg/l).
54

<b>THE IMPACT OF FINE CHEMICAL STRUCTURES OF </b><b>RESISTANT DEXTRINS ON MAINTENANCE OF GUT MICROBIOME DIVERSITY AND FUNCTION </b><b><i>IN VITRO </i></b><b>AND </b><b><i>IN VIVO</i></b>

Phuong Mai Lea Nguyen (17584623) 14 December 2023 (has links)
<p dir="ltr">Dietary fibers have been observed to modulate the gut microbiome in ways that prevent and moderate human diseases and confer health benefits onto their human host. How dietary fibers do this is through their structure; gut microbes are equipped with a variety of differ- ent carbohydrate-active enzymes (CAZymes) that allow some to hydrolyze glycosidic bonds, thereby utilizing the dietary fiber. The more complex the dietary fiber, the more diverse the maintained gut microbiota may be, as specialist species may be required for complete hydrol- ysis. Therefore, increasing structural complexity of dietary fibers may increase gut microbial diversity and help prevent diseases. To understand if structural features impact the gut mi- crobiome, a set of resistant glucans varying in structures, including mixed-linkage -glucans, resistant maltodextrins (similar to type IV resistant starch) and polydextroses, which are comprised entirely of glucose, were used as substrates in an in vitro sequential batch fermen- tation using fecal microbiota form three healthy donors as inocula. I measured metabolic outputs, growth curves, and community structures by 16S rRNA amplicon sequencing, which I analyzed for through alpha and beta diversity differences and taxa that overrepresented and increased in each treatment. My results show that, depending on the donor and the resistant glucan, structure does significantly impact the concentrations of short-chain fatty acids (SCFAs) and other metabolites that are produced. Resistant glucan structure also impacts alpha and beta diversity to a degree and linear discriminant analysis (by LEfSe) results also support that specific species have preference towards substrates as well. Next, resistant glucans were supplemented into a high-fat diet, and compared these diets to a low- fat diet (LFD), high-fat diet with cellulose (HFD), and high-fat without cellulose (HWC) in a mouse study using C57BL/6J mice over 4 weeks. Increasing microbial diversity will not only increase diversity in the gut microbiome, but it will also provide protective effects in behavior such as helping to prevent anxiety. I measured weight, metabolic outputs, 16S community structure, changes in alpha and beta diversity, and differential abundances of OTUs and taxa by discriminant analysis Effect Size (LEfSe) and Metastats, and anxiety behaviors using open field and light/dark box tests. Microbial community structure was significantly different in treatment groups from controls. Anxiety for mice in tapioca dextrin 01 (TD01), tapioca dextrin 03 (TD03), and resistant maltodextrin (RMF) treatment groups were gen- erally increased, suggesting that the chemical structure of these resistant dextrins may alter the gut microbiome in ways that may influence behavior.</p><p dir="ltr">My overall results support the hypothesis that the fine structural features of dietary fibers do significantly impact the gut microbiome by selecting for specific microbiota, and may even impact cognition and behavior.</p>
55

Biopolymer gene discovery and characterization using metagenomic libraries

Ohlhoff, Colin Walter 12 1900 (has links)
Thesis (MSc (Genetics. Institute of Plant Biotechnology))--Stellenbosch University, 2008. / Traditional methods used for the discovery of novel genes have previously relied upon the ability to culture the relevant microbes and then demonstrate the activity of a specific enzyme. Although these methods have proved successful in the past, they severely limit our access to the genomes of organisms which are not able to be cultured under laboratory conditions. It was therefore the aim of this project to use metagenomic strategies for the identification of novel polymer-producing genes with the prospect of commercial exploitation. In this study, soil-derived metagenomic libraries were functionally screened for potential -glucan producing clones using aniline blue staining. Positive reacting clones were selected and sequenced. Initial sequencing revealed a gene with high homology to previously described glucan synthases, the products of these genes all having significant industrial value. The clone was transformed into a suitable bacterial host, cultured and allowed to produce the polymer of interest. The polysaccharide was purified and subjected to various chemical analyses so as to confirm its monosaccharide composition. Data suggests that this polymer is composed mainly of glucose units and that it may be secreted out of the cell. Purification of the active enzyme was attempted using classical protein purification methods with faint activity being detected using Native polyacrylamide gel electrophoresis (PAGE). Further attempts to demonstrate activity were made through the construction of a GST (glutathione S-transferase) tagged fusion protein. The second part of this study focuses on the construction and screening of a metagenomic DNA library from whey, a by-product of the cheese manufacturing process. It was envisaged that this could provide a resource for the identification of high value polymers when lactose is provided as a sole carbon source. The library was screened for function using Congo Red for the detection of extra-cellular polysaccharides.
56

Efeito da dieta à base de Cogumelo do Sol (Agaricus blazei, Murrill) no parênquima pulmonar de ratos submetidos a estímulo carcinogênico pela nitrosamina 4-metilnitrosamina-1-3piridil-1 butanona (NNK) / Effect of diet of sun mushroom (Agaricus blazei Murrill) in the lung parenchyma of rats subjected to stimulation with the carcinogen nitrosamine-4-1-metilnitrosamine 3piridil-1butanone (NNK)

Carolina Croccia 18 August 2010 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Os cogumelos há muitos anos vêm sendo utilizados na alimentação por seus valores nutricionais e/ou como agente terapêutico. Um dos fungos mais estudados atualmente é o Agaricus blazei Murrill, popularmente conhecido como Cogumelo do Sol, em função dos efeitos benéficos que lhe é creditado na prevenção de câncer. O estudo analisou os efeitos da ingestão do A. blazei, no parênquima pulmonar de ratos Wistar submetidos a estímulo carcinógeno induzido pela nitrosamina 4-(metilnitrosamina)-1-(3-piridil)-1 butanona NNK, potente carcinogênico pulmonar sistêmico em roedores. Foi preparado extrato aquoso de A. blazei nas doses de 14,3 mg e 42,9 mg administrado por gavagem durante 22 semanas juntamente com a NNK administrada via subcutânea na dose de 1,5 mg de NNK/Kg de peso corporal do animal durante 20 semanas. Foram formados seis grupos experimentais: Grupo Controle (GC); Grupo Cogumelo do Sol nas doses de 14,3 mg e 42,9 mg por gavagem e injeção de óleo de milho subcutânea (CSOL 14,3 e CSOL 42,9); Grupo Nitrosamina (GN) com injeção de NNK subcutânea e salina por gavagem; Grupo Nitrosamina com Cogumelo do Sol nas doses de 14,3 e 42,9 mg (NSOL 14,3 e NSOL 42,9). Os animais foram submetidos à tomografia computadorizada (TC) para monitoramento do surgimento de possíveis tumores, foi analisado também peso corporal, consumo de ração ao longo de todo o experimento e realizada a composição centesimal do A. blazei Murrill. Ao final do experimento os animais foram mortos e foram analisados: hemograma completo, hepatograma, colesterol, triglicerídeo, análise macroscópica e microscópica do pulmão e a análise de curtose da curva do histograma fornecido pelo software BEBÚI utilizado no estudo através da imagem pulmonar da TC. Como conclusão foi verificado que a substância NNK na dose utilizada neste experimento não foi capaz de desenvolver uma neoplasia pulmonar nos animais estudados no período do experimento; no presente modelo experimental as diferenças encontradas nas análises histopatológicas e na análise da curtose mostram que a dose de cogumelo do sol de 14,3 mg se mostrou mais eficaz contra o surgimento de inflamação e opacidades pulmonares se comparada à dose de 42,9 mg. / The mushrooms have been used for many years as food for its nutritional value and/or as a therapeutic agent. One of the most studied fungus is currently the Agaricus blazei Murrill, popularly Known as Cogumelo do Sol, for its beneficial credited in the prevention of cancer. This study examined the effects of ingestion of A. blazei in the lung parenchyma of wistar rats subjected to stimulus-induced carcinogen 4 - (metilnitrosamina) -1 - (3-pyridyl) -1 butanone NNK, a potent systemic lung carcinogen in rodents. Was prepared aqueous extract of A. blazei in doses of 14,3 mg and 42,9 mg administered by gavage during 22 weeks together with NNK administered subcutaneously at a dose of 1,5 mg NNK/Kg body weight of the animal during 20 weeks. Were formed six groups: Control Group (CG); Mushroom Group at doses of 14,3 mg and 42,9 mg by gavage and injection of corn oil subcutaneously (CSOL 14.3 and 42.9); Group Nitrosamine (GN) with subcutaneous injection of NNK and saline by gavage; Group Nitrosamine + Mushroom at doses of 14,3 mg and 42,9 mg (NSOL 14.3 and NSOL 42.9). The animals were submitted to Computed Tomografy (CT) to monitor the possibility of development of lung tumors. Was also examined body weight and food intake throughout the experiment. At the end of 22 weeks, the experiment lasted for over four months for observation of development or growth of tumors via CT. After this period the animals were killed and analyzed: complete blood count, hepatogram, cholesterol, triglycerides, macroscopic and microscopic analysis of lung and kurtosis of the histogram curve supplied by the software used in the study called BEBÚI through the lung CT image. In conclusion it was found that NNK dose used on this study was not able to development a lung cancer in animals studied during the experiment. On this experimental model the differences found in histological analysis and the analysis of kurtosis shows that the dose of A. blazei of 14,3 mg was more effective against inflammation and the appearance of opacities compared to the dose of 42,9 mg.
57

Efeito de glucanas do fungo Caripia montagnei em modelo de inflama??o intestinal induzida por tnbs em ratos Wistar e em c?lulas de carcinoma de c?lon humano HT-29

Santos, Marilia da Silva Nascimento 08 April 2014 (has links)
Made available in DSpace on 2014-12-17T14:03:37Z (GMT). No. of bitstreams: 1 MariliaSNS_TESE.pdf: 2303324 bytes, checksum: d055f1a32ee94b3ffe5f389dbf9dffe0 (MD5) Previous issue date: 2014-04-08 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Compounds derived from fungi has been the subject of many studies in order to broaden the knowledge of their bioactive potential. Polysaccharides from Caripia montagnei have been described to possess anti-inflammatory and antioxidant properties. In this study, glucans extracted from Caripia montagnei mushroom were chemically characterized and their effects evaluated at different doses and intervals of treatment. It was also described their action on colonic injury in the model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS), and its action on cells of the human colon carcinoma (HT-29). Compounds extracted of C. montagnei contain high level of carbohydrates (96%), low content of phenolic compounds (1.5%) and low contamination with proteins (2.5%). The (FT-IR) and (NMR) analysis showed that polysaccharides from this species of mushroom are composed of &#945;- and &#946;-glucans. The colonic damage was evaluated by macroscopic, histological, biochemical and immunologic analyses. The results showed a reduction of colonic lesions in all groups treated with the glucans of Caripia montagnei (GCM). GCM significantly reduced the levels of IL-6 (50 and 75 mg/kg, p < 0.05), a major inflammatory cytokine. Biochemical analyses showed that such glucans acted on reducing levels of alkaline phosphatase (75 mg/kg, p < 0.01), nitric oxide (p < 0.001), and myeloperoxidase (p < 0.001). These results were confirmed microscopically by the reduction of cellular infiltration. The increase of catalase activity suggest a protective effect of GCM on colonic tissue, confirming their anti-inflammatory potential. GCM displayed cytostatic activity against HT-29 cells, causing accumulation of cells in G1 phase, blocking the cycle cell progression. Those glucans also showed ability to modulate the adhesion of HT-29 cells to Matrigel? and reduced the oxidative stress. The antiproliferative activity against HT-29 cells displayed by GCM (p <0.001) can be attributed to its cytostatic activity and induction of apoptosis by GCM / Compostos derivados de fungos tem sido alvo de muitos estudos a fim de desenvolver o conhecimento acerca de seu potencial bioativo. Polissacar?deos de Caripia montagnei j? foram descritos por possu?rem propriedades anti-inflamat?ria e antioxidante. Neste estudo, os polissacar?deos extra?dos do fungo Caripia montagnei foram caracterizados quimicamente e seus efeitos sobre as les?es intestinais foram avaliados em diferentes intervalos de tratamento no modelo de colite induzida por ?cido 2,4,6 - trinitrobenzenossulf?nico (TNBS), verificou-se ainda sua a??o sobre c?lulas do carcinoma de c?lon humano, HT-29. Na an?lise realizada no extrato obtido de C. montagnei foi verificado que este ? formado principalmente, por carboidratos (96%) apresentando um baixo teor de compostos fen?licos (1,5%) e baixa contamina??o prot?ica (2,5%). As an?lises por espectroscopia de infra vermelho (FT-IR) e resson?ncia magn?tica nuclear (RMN) mostraram que os polissacar?deos desta esp?cie de fungo s?o &#945; e &#946; -glucanas. O dano col?nico foi avaliado por an?lises macrosc?picas, histol?gicas, bioqu?micas e imunol?gicas. Os resultados mostraram a redu??o das les?es no c?lon em todos os grupos tratados com as glucanas (GCM). GCM reduziram significativamente os n?veis de IL-6 (50 e 75 mg/Kg, p < 0,05), uma importante citocina inflamat?ria. As an?lises bioqu?micas mostraram que essas glucanas atuaram na redu??o dos n?veis de fosfatase alcalina (75 mg/Kg, p < 0,01), ?xido n?trico (p < 0,001) e mieloperoxidase (p < 0,001). Estes resultados foram confirmados pela redu??o da infiltra??o celular observado microscopicamente. O aumento da atividade da catalase, sugere um efeito protetor de GCM no tecido do c?lon, o que confirma o seu potencial anti-inflamat?rio. GCM mostraram atividade citost?tica sobre as c?lulas HT-29, causando ac?mulo de c?lulas na fase G1 e impedindo, assim, a progress?o do ciclo celular. As glucanas deste estudo tamb?m mostraram habilidade em modular a ades?o de c?lulas HT-29 ao Matrigel? e reduzir o estresse oxidativo nessas c?lulas. A atividade antiproliferativa contra c?lulas HT-29 exibida por GCM pode ser atribu?da ? sua a??o citost?tica ou indu??o da apoptose por essas glucanas
58

Efeito da dieta à base de Cogumelo do Sol (Agaricus blazei, Murrill) no parênquima pulmonar de ratos submetidos a estímulo carcinogênico pela nitrosamina 4-metilnitrosamina-1-3piridil-1 butanona (NNK) / Effect of diet of sun mushroom (Agaricus blazei Murrill) in the lung parenchyma of rats subjected to stimulation with the carcinogen nitrosamine-4-1-metilnitrosamine 3piridil-1butanone (NNK)

Carolina Croccia 18 August 2010 (has links)
Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Os cogumelos há muitos anos vêm sendo utilizados na alimentação por seus valores nutricionais e/ou como agente terapêutico. Um dos fungos mais estudados atualmente é o Agaricus blazei Murrill, popularmente conhecido como Cogumelo do Sol, em função dos efeitos benéficos que lhe é creditado na prevenção de câncer. O estudo analisou os efeitos da ingestão do A. blazei, no parênquima pulmonar de ratos Wistar submetidos a estímulo carcinógeno induzido pela nitrosamina 4-(metilnitrosamina)-1-(3-piridil)-1 butanona NNK, potente carcinogênico pulmonar sistêmico em roedores. Foi preparado extrato aquoso de A. blazei nas doses de 14,3 mg e 42,9 mg administrado por gavagem durante 22 semanas juntamente com a NNK administrada via subcutânea na dose de 1,5 mg de NNK/Kg de peso corporal do animal durante 20 semanas. Foram formados seis grupos experimentais: Grupo Controle (GC); Grupo Cogumelo do Sol nas doses de 14,3 mg e 42,9 mg por gavagem e injeção de óleo de milho subcutânea (CSOL 14,3 e CSOL 42,9); Grupo Nitrosamina (GN) com injeção de NNK subcutânea e salina por gavagem; Grupo Nitrosamina com Cogumelo do Sol nas doses de 14,3 e 42,9 mg (NSOL 14,3 e NSOL 42,9). Os animais foram submetidos à tomografia computadorizada (TC) para monitoramento do surgimento de possíveis tumores, foi analisado também peso corporal, consumo de ração ao longo de todo o experimento e realizada a composição centesimal do A. blazei Murrill. Ao final do experimento os animais foram mortos e foram analisados: hemograma completo, hepatograma, colesterol, triglicerídeo, análise macroscópica e microscópica do pulmão e a análise de curtose da curva do histograma fornecido pelo software BEBÚI utilizado no estudo através da imagem pulmonar da TC. Como conclusão foi verificado que a substância NNK na dose utilizada neste experimento não foi capaz de desenvolver uma neoplasia pulmonar nos animais estudados no período do experimento; no presente modelo experimental as diferenças encontradas nas análises histopatológicas e na análise da curtose mostram que a dose de cogumelo do sol de 14,3 mg se mostrou mais eficaz contra o surgimento de inflamação e opacidades pulmonares se comparada à dose de 42,9 mg. / The mushrooms have been used for many years as food for its nutritional value and/or as a therapeutic agent. One of the most studied fungus is currently the Agaricus blazei Murrill, popularly Known as Cogumelo do Sol, for its beneficial credited in the prevention of cancer. This study examined the effects of ingestion of A. blazei in the lung parenchyma of wistar rats subjected to stimulus-induced carcinogen 4 - (metilnitrosamina) -1 - (3-pyridyl) -1 butanone NNK, a potent systemic lung carcinogen in rodents. Was prepared aqueous extract of A. blazei in doses of 14,3 mg and 42,9 mg administered by gavage during 22 weeks together with NNK administered subcutaneously at a dose of 1,5 mg NNK/Kg body weight of the animal during 20 weeks. Were formed six groups: Control Group (CG); Mushroom Group at doses of 14,3 mg and 42,9 mg by gavage and injection of corn oil subcutaneously (CSOL 14.3 and 42.9); Group Nitrosamine (GN) with subcutaneous injection of NNK and saline by gavage; Group Nitrosamine + Mushroom at doses of 14,3 mg and 42,9 mg (NSOL 14.3 and NSOL 42.9). The animals were submitted to Computed Tomografy (CT) to monitor the possibility of development of lung tumors. Was also examined body weight and food intake throughout the experiment. At the end of 22 weeks, the experiment lasted for over four months for observation of development or growth of tumors via CT. After this period the animals were killed and analyzed: complete blood count, hepatogram, cholesterol, triglycerides, macroscopic and microscopic analysis of lung and kurtosis of the histogram curve supplied by the software used in the study called BEBÚI through the lung CT image. In conclusion it was found that NNK dose used on this study was not able to development a lung cancer in animals studied during the experiment. On this experimental model the differences found in histological analysis and the analysis of kurtosis shows that the dose of A. blazei of 14,3 mg was more effective against inflammation and the appearance of opacities compared to the dose of 42,9 mg.
59

Estudo químico de carboidratos isolados do micélio do cogumelo medicinal Grifola frondosa (“Maitake”) / Chemical study of carbohydrates isolated from the mycelium of the medicinal mushroom Grifola frondosa ("Maitake")

Silva, Estefânia Viano da 26 June 2014 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-10-20T17:56:33Z No. of bitstreams: 2 Dissertação - Estefânia Viano da Silva - 2014.pdf: 4645592 bytes, checksum: f3321dacb1ccfd2f2b017d08f8e3b578 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-10-20T17:58:09Z (GMT) No. of bitstreams: 2 Dissertação - Estefânia Viano da Silva - 2014.pdf: 4645592 bytes, checksum: f3321dacb1ccfd2f2b017d08f8e3b578 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-10-20T17:58:09Z (GMT). No. of bitstreams: 2 Dissertação - Estefânia Viano da Silva - 2014.pdf: 4645592 bytes, checksum: f3321dacb1ccfd2f2b017d08f8e3b578 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-06-26 / The mushrooms have been used as food and medicine for thousands of years. Among them, Grifola frondosa (“Maitake”) may be on the most versatile and promising medicinal mushrooms for use as a dietary supplement. Besides the high nutritional value, they are a good source of compounds such as carbohydrates that can act as biological response modifiers. In this work, β-D-glucans (PSF2-GfM and MRSF2K-GfM fractions) and heteropolysaccharides unusual in the literature (MEPF3CW-GfM and PF2K-GfM fractions) were isolated from the mycelium, grown in solid culture, of the G. frondosa, by successive aqueous and alkaline extractions, followed by fractionation through freeze-thawing, precipitation of soluble material with a Fehling solution, and dialysis using a membrane with an exclusion limit of 1000 kDa. The chemical structures were established based on monossacharide composition, periodate oxidation, methylation analysis, HPSEC-MALLS and NMR studies. The branched β-D-glucans (GLC-GfM) found were similar to those previously described for the fungus, which contains a (13)- linked β-Glcp main-chain, substituted at O-6 by single-unit -Glcp side-chains, on the average of one to every third residues of the backbone, but with different molar masses and water solubility. In adittion, novel heteropolymers were obtained. One was a fucomannogalactan (FMG-GfM), with a molar mass of 175 x 103 g mol-1, was shown to have a main chain of (1→6)-linked α-D-Galp and 3-O-Me-α-DGalp, both of which are partially substituted at O-2, principally, by 3-O-α-D-Manp-α-LFucp groups. The other was a fucoxylomannan (FXM-GfM) (Mw 202 x 103 g.mol-1), which consisted of backbone of (13)-linked α-D-Manp units, totally substituted at O-4 mainly by 4-O-α-L-Fucp-β-D-Xylp disaccharide. Thus, the polymers obtained from Grifola frondosa may could be good candidates for evaluation of its biological effect, considering the results obtained for others similar mushrooms polysaccharides. / Os cogumelos têm sido usados como alimentos e remédios por milhares de anos. Entre eles, o “Maitake” (Grifola frondosa) pode ser um dos cogumelos medicinais mais versáteis e promissores para o uso como um suplemento dietético. Além do valor nutricional elevado, eles são uma boa fonte de compostos, como os carboidratos, que podem agir como modificadores de resposta biológica. Neste trabalho, foram isolados do micélio (cultivado em meio sólido) de G. frondosa as β-D-glucanas (frações PSF2KGfM e MRSF2K-GfM) e heteropolissacarídeos (frações MePF3CW-GfM e PF2K-GfM) não comumente encontrados na literatura, por sucessivas extrações aquosas e alcalinas, seguido por fracionamento através do processo de congelamento/degelo, precipitação das frações solúveis em água com solução de Fehling e diálise em membranas com limite de exclusão de 1000 kDa. A estrutura química foi determinada através das análises de composição mossacarídica, oxidação com periodato de sódio, metilação, HPSEC-MALLS e RMN. As β-D-glucanas (GLC) isoladas foram similares àquelas previamente descritas para este fungo, as quais contém uma cadeia principal formada por unidades de 3-O-β-D-Glcp, podendo ser substituídas em O-6 por terminais não redutores de β-Glcp (1 ramificação a cada três unidades da cadeia principal), distinguindo-as quanto à solubilidade em água e tamanho (massa molar). Além destas, foram obtidos novos heteropolímeros. Um deles foi uma fucomanogalactana (FMGGfM), com uma massa molar de 175 x 103 g mol-1, a qual possui um core constituído por unidades de 6-O-α-D-Galp e 6-O-(3-O-Me-α-D-Galp), sendo ambas parcialmente substituídas em O-2 por 3-O-α-D-Manp-α-L-Fucp. O outro heteropolissacarídeo isolado consiste em uma fucoxilomanana (FXM-GfM) (Mw 202 x 103 g.mol-1) formada por unidades de α-D-Manp unidas por ligações glicosídicas do tipo (13) as quais se encontram ramificadas em O-4 principalmente pelo dissacarídeo 4-O-α-L-Fucp-β-DXylp. Considerando os efeitos terapêuticos apresentados por moléculas similares descritas para macrofungos, estes podem ser bons candidatos para avaliação do efeito biológico.
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Resposta imune à vacina contra hepatite B com suplementação de beta-glucanas

Oba, Paula Franco January 2020 (has links)
Orientador: Marjorie de Assis Golim / Resumo: A infecção crônica pelo vírus da hepatite B (VHB) é a principal causa de cronificação da hepatite, cirrose hepática e carcinoma hepatocelular em humanos. A vacinação contra hepatite B é essencial a saúde da população, sendo a medida de menor custo e maior eficiência para controlar o vírus. A vacina desencadeia resposta imune com produção de anticorpos contra o antígeno de superfície do VHB (anti-HBs), contudo, alguns indivíduos não desenvolvem imunidade efetiva, havendo necessidade de doses adicionais. Assim, estimular a resposta imune nos indivíduos já vacinados, porém pouco respondedores ou não respondedores previamente, poderia contribuir para o aumento da produção de anticorpos e persistência dos mesmos ao longo do tempo. Considerando o potencial imunomodulador de β-glucanas, inclusive no aumento da ativação de células T e B em resposta a antígenos, propôs-se neste estudo avaliar a influência do uso de β-glucanas como suplemento alimentar em indivíduos com imunidade não efetiva pós-vacina, que necessitassem de dose booster. Foram incluídos 46 doadores de sangue do Hemocentro de Botucatu, com idade entre 18 anos e 25 anos completos, do sexo masculino, vacinados com três doses para hepatite B na primeira infância. Aqueles que apresentaram anti-HBs<10UI/L foram considerados não imunes, sendo mantidos no estudo (n=31) e divididos em dois grupos de forma aleatória. Ambos os grupos receberam booster da vacina, sendo um grupo suplementado via oral com cápsulas de amido (n=11; pl... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Chronic hepatitis B virus (HBV) infection is the main cause of hepatitis chronification, liver cirrhosis and hepatocellular carcinoma in humans. Vaccination against hepatitis B is essential to the health of the population, being the least costly and most efficient measure to control the virus. The vaccine triggers an immune response with the production of antibodies against HBV surface antigen (Anti-HBs), however, some individuals do not develop effective immunity, requiring additional doses. Thus, stimulating the immune response in individuals who have already been vaccinated, but with little or no previous response, could contribute to increased antibody production and persistence over time. Considering the immunomodulatory potential of β-glucans, including the increased activation of T and B cells in response to antigens, it was proposed in this study to evaluate the influence of the use of βglucans as a food supplement in individuals with post-vaccine ineffective immunity , who needed a booster dose. 46 blood donors from the Hemocenter of Botucatu, aged between 18 and 25 years old, male, who received three doses of hepatitis B vaccine in childhood were included. Those who had anti-HBs <10 IU / L were considered non-immune, being maintained in the study (n = 31) and randomly divided into two groups. Both groups received a vaccine booster, one group supplemented orally with starch capsules (n = 11; placebo - 500mg / day), and the other with β-glucans (n = 20; 500mg / day) f... (Complete abstract click electronic access below) / Mestre

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