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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

Variation in the blood chemical constituents of reindeer:significance of season, nutrition and other extrinsic and intrinsic factors

Säkkinen, H. (Hannele) 09 August 2005 (has links)
Abstract Reindeer management in the Fennoscandian area is currently facing challenges such as degradation of winter pastures, which may lead in the most severely affected areas to a concurrent decline in reindeer herd productivity. The use of often expensive supplementary feeding to prevent production losses has increased the demand for studies on the physiological effects of nutritional restriction and supplementary feeding. The knowledge obtained from such studies could be used, for example, to monitor the condition of reindeer in studies assessing herd productivity levels in different pasture conditions and management systems or sustainable use of pasture resources. In this thesis, the effects of season, year, pasture area, body mass, pregnancy and other extrinsic and intrinsic factors on the variation of blood chemical constituents of reindeer were studied in free-ranging animals under natural foraging conditions. The studied blood chemical constituents covered a wide range of parameters related to protein, carbohydrate, lipid and mineral metabolism. The same blood chemical constituents were studied in captive reindeer under defined feeding conditions, allowing an analysis of the effects of dietary protein, energy and mineral intake on the selected blood constituents and their comparison to a conventional measure of the animals' condition, live body mass. According to the results, free-ranging reindeer showed great variation in the concentrations of blood chemical constituents compared to the reference values of domesticated ruminants. Intrinsic factors such as body mass, pregnancy and age had only a minor influence on the variation of the studied parameters, whereas extrinsic factors such as season, year and pasture area, which were characterized by marked changes in environmental and nutritional conditions, explained the majority of the variation. The results obtained from captive animals in defined feeding conditions and from free-ranging animals foraging on natural pastures led to the conclusion that blood total proteins, albumin, urea, creatinine, urea:creatinine ratio, magnesium, inorganic phosphate and, to a lesser extent, globulins and albumin:globulin ratio responded to the changes in feed quality and availability and were the most suitable blood constituents to be used as nutritional biomarkers for reindeer.
52

Molecular studies of the alpha globin genes in Quebec populations

Akerman, Beverly January 1987 (has links)
No description available.
53

Redução das imunoglobulinas induzida pelo abatacepte não se associa com eventos infecciosos / Abatacept related gamma-globulin reduction: no association with infections

Dinis, Valquiria Garcia 21 September 2017 (has links)
Introdução: recentemente, foi descrita a ação do abatacepte (ABA) na redução nos níveis de imunoglobulinas (Ig) plasmáticas em pacientes com artrite reumatoide (AR). No entanto, a possível associação destes resultados com infecções não foi avaliada até o presente momento. Objetivos: comparar os níveis totais de Igs, suas frações (IgG, IgM, IgA) e das cadeias leves (kappa e lambda) em pacientes com AR em uso de ABA vs. agentes anti-TNF semestralmente, durante 24 meses de uso, e correlacioná-los com a presença de infecções. Método: dezoito pacientes consecutivos com AR tratados abatacepte (ABA-AR) foram comparados com 18 pacientes com AR tratados com anti-TNF (aTNF-AR). Dados clínicos, laboratoriais e dosagens de imunoglobulinas total, suas frações (IgG, IgM, IgA) e das cadeias leves (kappa e lambda) foram obtidos a cada seis meses até o tempo total de 24 meses. Foi feito screening sistemático para presença de infecções. Os critérios de exclusão foram: uso prévio de abatacepte/rituximabe e hipogamablobulinemia basal (< 0,7 g/dL). Resultados: no baseline, as medianas da idade (55 vs. 53 anos, P = 0,92), porcentagem de gênero feminino (78 vs. 78%, P = 1,0), comorbidades (28 vs. 28%, P = 1,0), DAS-28 (5,73 vs. 5,67, P = 0,93), HAQ (1,5 vs. 1,13, P = 0,1), VHS (21,5 vs. 22 mm/1ahora, P = 0,49), PCR (15,5 vs. 12 mg/dL, P = 0,43) e contagem de linfócitos (2.200 vs. 1.800/mm3, P = 0,18) foram semelhantes entre os grupos ABA-AR e aTNF-AR, assim como as medianas da gamaglobulina total (1,4 vs. 1,35 g/dL, P = 0,74), IgG (1.168 vs. 1.079 mg/dL, P = 0,46), IgM (107 vs. 113mg/dL, P = 0,38), IgA (333 vs. 322 mg/dL, P = 0,71), kappa (342 vs. 249 mg/dL, P = 0,39) e lambda (170 vs. 150 mg/dL, P = 0,20). No grupo ABA-AR, após seis meses de uso, houve uma queda dos níveis séricos de gamaglobulina total (1,4 vs. 1,05 g/dL, P < 0,001), IgG (1.168 vs. 997 mg/dL, P < 0,001), IgA (333 vs. 278 mg/dL, P < 0,001), kappa (342 vs. 257 mg/dL, P < 0,001) e lambda (170 vs. 144 mg/dL, P < 0,001). Esses níveis permaneceram estáveis dos seis meses até os 24 meses de tratamento (P > 0,05). Em contraste, no grupo aTNF-AR, não houve alteração nos níveis séricos da gamaglobulina total, suas frações e cadeias leves (P > 0,05) em nenhum momento. A variação negativa da gamaglobulina total, IgG, IgM, IgA, kappa e lambda no grupo ABA-AR foi diferente do grupo aTNF-AR (P < 0,05) em todas as avaliações. No entanto, a frequência de infecções foi semelhante entre os grupos (77,8 vs. 88,9%, P = 0,66) e não se associou às variações da gamaglobulina total, de suas frações ou das cadeias leves em nenhum dos dois grupos. Não houve infecções graves durante o período do estudo. Conclusão: o presente estudo demonstra que o abatacepte, mas não os aTNFs, induz uma queda nos níveis de imunoglobulina total, suas frações e cadeias leves nos primeiros seis meses de uso, com estabilidade nos níveis até 24 meses. No entanto, essa queda não está relacionada ao aumento da frequência de infecções nesse grupo de pacientes / Objective: to evaluate the influence of abatacept on gamma-globulin levels in comparison to anti-TNF treatment and correlate these effects with infections frequency in rheumatoid arthritis (RA) patients. Methods: eighteen consecutive RA patients undergoing abatacept (ABA-RA) were compared to 18 patients treated with anti-TNF (aTNF-RA) agents with similar ages. Clinical and laboratory data, total, specific (IgG, IgM, IgA) gamma-globulin and free light chains (FLC) levels were assessed before and every six months during biologic treatment, up to 24 months. Systematic clinical screening protocol for infection was performed. Exclusion criteria were previous abatacept/rituximab treatments and low gamma-globulin level ( < 0.7 g/dL). Results: at baseline, median age (55 vs. 53 years, P = 0.92), female gender (78 vs. 78%, P = 1.0), co morbities (28 vs. 28%, P = 1), DAS-28 (5.73 vs. 5.67, P = 0.93), HAQ (1.5 vs. 1.13, P = 0.1), ESR (21.5 vs. 22mm/1sth, P = 0.49), CRP (15.5 vs. 12mg/dL, P = 0.43) and lymphocyte count (2,200 vs. 1,800/mm3, P = 0.18) were comparable in ABA-RA and aTNF-RA. Medians of gamma-globulin (1.4 vs. 1.35g/dL, P = 0.74), IgG (1,168 vs. 1,079mg/dL, P = 0.46), IgM (107 vs. 113mg/dL, P = 0.38), IgA (333 vs. 322mg/dL, P = 0.71), kappa (342 vs. 249mg/dL, P = 0.39), lambda (170 vs. 150mg/dL, P = 0.20) were also alike. In ABA-RA, total gamma-globulin (1.4 vs. 1.05 g/dL, P < 0.001), IgG (1,168 vs. 997 mg/dL, P < 0.001), IgA (333 vs. 278 mg/dL, P < 0.001), kappa (341.5 vs. 257 mg/dL, P < 0.001), lambda (169.5 vs. 144.3 mg/dL, P < 0.001) levels decreased after six months in comparison to baseline values and persisted stable up to 24 months (P > 0.05). In contrast, in aTNF-RA no decrease in total, specific gamma-globulin levels or FLC was seen (P > 0.05). The negative variation of gamma-globulin, IgG, IgM, IgA, kappa and lambda levels in ABA-RA was different from aTNF-RA (P < 0.05) at all evaluations. However, the infection rates (77.8 vs. 88.9%, P = 0.66) were similar and not associated to variations in total or specific gamma-globulin levels in any group. No severe infection was observed. Conclusion: these comparative data demonstrate that ABA, but not the aTNF, induces a non-progressive and mild, but significant reduction in gamma-globulin levels. We further demonstrated that this alteration is not clinically relevant since it is not associated with increased infection rate
54

Redução das imunoglobulinas induzida pelo abatacepte não se associa com eventos infecciosos / Abatacept related gamma-globulin reduction: no association with infections

Valquiria Garcia Dinis 21 September 2017 (has links)
Introdução: recentemente, foi descrita a ação do abatacepte (ABA) na redução nos níveis de imunoglobulinas (Ig) plasmáticas em pacientes com artrite reumatoide (AR). No entanto, a possível associação destes resultados com infecções não foi avaliada até o presente momento. Objetivos: comparar os níveis totais de Igs, suas frações (IgG, IgM, IgA) e das cadeias leves (kappa e lambda) em pacientes com AR em uso de ABA vs. agentes anti-TNF semestralmente, durante 24 meses de uso, e correlacioná-los com a presença de infecções. Método: dezoito pacientes consecutivos com AR tratados abatacepte (ABA-AR) foram comparados com 18 pacientes com AR tratados com anti-TNF (aTNF-AR). Dados clínicos, laboratoriais e dosagens de imunoglobulinas total, suas frações (IgG, IgM, IgA) e das cadeias leves (kappa e lambda) foram obtidos a cada seis meses até o tempo total de 24 meses. Foi feito screening sistemático para presença de infecções. Os critérios de exclusão foram: uso prévio de abatacepte/rituximabe e hipogamablobulinemia basal (< 0,7 g/dL). Resultados: no baseline, as medianas da idade (55 vs. 53 anos, P = 0,92), porcentagem de gênero feminino (78 vs. 78%, P = 1,0), comorbidades (28 vs. 28%, P = 1,0), DAS-28 (5,73 vs. 5,67, P = 0,93), HAQ (1,5 vs. 1,13, P = 0,1), VHS (21,5 vs. 22 mm/1ahora, P = 0,49), PCR (15,5 vs. 12 mg/dL, P = 0,43) e contagem de linfócitos (2.200 vs. 1.800/mm3, P = 0,18) foram semelhantes entre os grupos ABA-AR e aTNF-AR, assim como as medianas da gamaglobulina total (1,4 vs. 1,35 g/dL, P = 0,74), IgG (1.168 vs. 1.079 mg/dL, P = 0,46), IgM (107 vs. 113mg/dL, P = 0,38), IgA (333 vs. 322 mg/dL, P = 0,71), kappa (342 vs. 249 mg/dL, P = 0,39) e lambda (170 vs. 150 mg/dL, P = 0,20). No grupo ABA-AR, após seis meses de uso, houve uma queda dos níveis séricos de gamaglobulina total (1,4 vs. 1,05 g/dL, P < 0,001), IgG (1.168 vs. 997 mg/dL, P < 0,001), IgA (333 vs. 278 mg/dL, P < 0,001), kappa (342 vs. 257 mg/dL, P < 0,001) e lambda (170 vs. 144 mg/dL, P < 0,001). Esses níveis permaneceram estáveis dos seis meses até os 24 meses de tratamento (P > 0,05). Em contraste, no grupo aTNF-AR, não houve alteração nos níveis séricos da gamaglobulina total, suas frações e cadeias leves (P > 0,05) em nenhum momento. A variação negativa da gamaglobulina total, IgG, IgM, IgA, kappa e lambda no grupo ABA-AR foi diferente do grupo aTNF-AR (P < 0,05) em todas as avaliações. No entanto, a frequência de infecções foi semelhante entre os grupos (77,8 vs. 88,9%, P = 0,66) e não se associou às variações da gamaglobulina total, de suas frações ou das cadeias leves em nenhum dos dois grupos. Não houve infecções graves durante o período do estudo. Conclusão: o presente estudo demonstra que o abatacepte, mas não os aTNFs, induz uma queda nos níveis de imunoglobulina total, suas frações e cadeias leves nos primeiros seis meses de uso, com estabilidade nos níveis até 24 meses. No entanto, essa queda não está relacionada ao aumento da frequência de infecções nesse grupo de pacientes / Objective: to evaluate the influence of abatacept on gamma-globulin levels in comparison to anti-TNF treatment and correlate these effects with infections frequency in rheumatoid arthritis (RA) patients. Methods: eighteen consecutive RA patients undergoing abatacept (ABA-RA) were compared to 18 patients treated with anti-TNF (aTNF-RA) agents with similar ages. Clinical and laboratory data, total, specific (IgG, IgM, IgA) gamma-globulin and free light chains (FLC) levels were assessed before and every six months during biologic treatment, up to 24 months. Systematic clinical screening protocol for infection was performed. Exclusion criteria were previous abatacept/rituximab treatments and low gamma-globulin level ( < 0.7 g/dL). Results: at baseline, median age (55 vs. 53 years, P = 0.92), female gender (78 vs. 78%, P = 1.0), co morbities (28 vs. 28%, P = 1), DAS-28 (5.73 vs. 5.67, P = 0.93), HAQ (1.5 vs. 1.13, P = 0.1), ESR (21.5 vs. 22mm/1sth, P = 0.49), CRP (15.5 vs. 12mg/dL, P = 0.43) and lymphocyte count (2,200 vs. 1,800/mm3, P = 0.18) were comparable in ABA-RA and aTNF-RA. Medians of gamma-globulin (1.4 vs. 1.35g/dL, P = 0.74), IgG (1,168 vs. 1,079mg/dL, P = 0.46), IgM (107 vs. 113mg/dL, P = 0.38), IgA (333 vs. 322mg/dL, P = 0.71), kappa (342 vs. 249mg/dL, P = 0.39), lambda (170 vs. 150mg/dL, P = 0.20) were also alike. In ABA-RA, total gamma-globulin (1.4 vs. 1.05 g/dL, P < 0.001), IgG (1,168 vs. 997 mg/dL, P < 0.001), IgA (333 vs. 278 mg/dL, P < 0.001), kappa (341.5 vs. 257 mg/dL, P < 0.001), lambda (169.5 vs. 144.3 mg/dL, P < 0.001) levels decreased after six months in comparison to baseline values and persisted stable up to 24 months (P > 0.05). In contrast, in aTNF-RA no decrease in total, specific gamma-globulin levels or FLC was seen (P > 0.05). The negative variation of gamma-globulin, IgG, IgM, IgA, kappa and lambda levels in ABA-RA was different from aTNF-RA (P < 0.05) at all evaluations. However, the infection rates (77.8 vs. 88.9%, P = 0.66) were similar and not associated to variations in total or specific gamma-globulin levels in any group. No severe infection was observed. Conclusion: these comparative data demonstrate that ABA, but not the aTNF, induces a non-progressive and mild, but significant reduction in gamma-globulin levels. We further demonstrated that this alteration is not clinically relevant since it is not associated with increased infection rate
55

ProteÃnas de sementes de Amburama Cearensis (Allemao) A. C. Smith: Valor Nutricional e bioatividade contra patÃgenos e vetores de doenÃas / Amburama seed proteins cearensis (AllemÃo) AC Smith: Nutritional Value and bioactivity against pathogens and disease vectors

Davi Felipe Farias 06 March 2009 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Amburana cearensis (Allemao) A. C. Smith, usually known in portuguese language as âImburana-de-Cheiroâ or âCumaruâ, is a leguminous tree, subfamily Papilionoideae with common occurrence in âCaatingaâ Dominium. Despite the numerous ethnobotanical uses, few studies report biological activities of medical interest and / or agribusiness for this species or yet its utilization as food for humans and / or animals. This study aimed to evaluate the proteins of A. cearensis on its nutritional value associated with its biochemical characterization and as to the presence of bioactivity against bacteria, yeasts and filamentous fungi, all pathogens of humans, animals or plants of economic importance, and also against the vectors of disease, Aedes aegypti and Ae. albopictus. For this, seeds were collected in areas of caatinga trees in the municipality of Quixadà - CE and, subsequently, dried and finely ground. The seeds of A. cearensis have high nutritional potential, evidenced by the high content of proteins (22.69 &#61617; 0.81 g 100 g-1), lipid (24.45 2.02 g 100 g-1) and dietary fiber (34.75 1.78 g 100 g-1), keeping smaller quantities of starch (11.43 0.18 g 100 g-1), of total sugars (5.60 0.09 g 100 g-1) and minerals (4.51 0.21 g 100 g-1). Its amino acid composition is comparable to that of soybeans and beans. Moreover, the seeds have moderate levels of antinutritional factors, being detected only trypsin inhibitory activity (27.41  0.03 gTI Kg-1), urease activity (434  34 U kg-1) and some secondary metabolites such as tannins, phenols, flavones, flavonols, and xantone steroids. Chemical components, probably of low molecular mass present in seeds flour incorporated into diets, seem to interfere with their acceptance and use by animals since when the protein fraction (F0/90), obtained from its soluble protein, was incorporated into the balanced diet, the rats accepted well the diets and their performance indicated that F0/90 a good source of protein, comparable to major sources of vegetable protein such as soy and beans. Proteins of A. cearensis seeds are mainly composed of globulins (74.43 g 100 g-1) and albumins (14.23 g 100 g-1), with smaller quantities of glutelin basic proteins (10.07 g 100g-1), prolamins (1.20 g 100 g-1) and glutelin acidic proteins (0.07 g 100 g-1). The seeds crude extract (GE) offers a wide variety of proteins as shown by electrophoretic profiles with a predominance of proteins with apparent molecular mass over 45.0 kDa. The seeds of A. cearensis show also high bioactive potential, especially the activities of their majority proteins (albumins and globulins) against the growth of human pathogenic bacteria and yeast and phytopathogenic filamentous fungi, and against larvae of Aedes aegypti and Ae. albopictus. The inhibitory activity of the growth of phytopathogenic fungi concentrated in the albumins F70/90 fraction, being rich in proteins of low molecular mass (<30 kDa). Thus we can conclude that F0/90 is a good source of protein food when compared to other plant sources already used by the population. In addition, the globulins and albumins of A. cearensis are promising sources of bioactive proteins to be studied further and in greater purity. / Amburana cearensis (Allemao) A. C. Smith, popularmente conhecida como Imburana-de-Cheiro ou Cumaru, à uma leguminosa arbÃrea da subfamÃlia Papilionoideae de ocorrÃncia freqÃente na regiÃo do domÃnio Caatinga. Apesar dos inÃmeros usos etnobotÃnicos, poucos trabalhos relatam atividades biolÃgicas de interesse mÃdico e/ou agroindustrial para esta espÃcie ou, mesmo, sua utilizaÃÃo como fonte de alimento para humanos e/ou animais. Assim, o presente trabalho objetivou avaliar as proteÃnas de A. cearensis quanto a seu valor nutricional aliado à sua caracterizaÃÃo bioquÃmica e quanto à presenÃa de bioatividade contra bactÃrias, leveduras e fungos filamentosos, todos patÃgenos do homem, de animais ou de plantas de importÃncia econÃmica, e, ainda, contra os vetores de doenÃas, Aedes aegypti e Ae. albopictus. Para tanto, sementes foram coletadas em Ãrea de caatinga arbÃrea, no municÃpio de Quixadà â CE, sendo, posteriormente, desidratadas e finamente moÃdas. As sementes de A. cearensis possuem alto potencial nutricional, revelado pelo alto teor de proteÃnas (22,69 &#61617; 0,81 g. 100 g-1), lipÃdios (24,45 2,02 g. 100 g-1) e fibra alimentrar (34,75 1,78 g.100 g-1), retendo quantidades menores de amido (11,43 0,18 g.100g-1), aÃÃcares totais (5,60 0,09 g.100 g-1), e de minerais (4,51 0,21 g.100 g-1). Sua composiÃÃo aminoacÃdica à comparÃvel Ãquela da soja e feijÃo. AlÃm disso, as sementes apresentam moderados nÃveis de fatores antinutricionais, sendo detectados apenas atividade inibitÃria de tripsina (27,41  0,03 gTI.Kg-1), atividade ureÃsica (434,0  34,0 U.Kg-1) e alguns metabÃlitos secundÃrios, como taninos, fenÃis, flavonas, flavonÃis, xantonas e esterÃides. Componentes quÃmicos, provavelmente de baixa massa molecular, presentes nas sementes incorporadas a dietas interferem na sua aceitaÃÃo e aproveitamento por parte dos animais, uma vez que quando a fraÃÃo proteica (F0/90) obtida de suas proteÃnas solÃveis à incorporada à dieta balanceada, apresenta boa aceitaÃÃo pelos animais, mostrando-se uma boa fonte de proteÃnas, comparÃvel a importantes fontes de proteÃnas vegetais como a soja e os feijÃes. As proteÃnas das sementes de A. cearensis sÃo compostas principalmente por globulinas (74,43 g. 100g-1) e albuminas (14,23 g.100 g-1), com quantidades menores de proteÃnas do tipo glutelinas bÃsicas (10,07 g.100 g-1), prolaminas (1,20 g.100 g-1) e proteÃnas do tipo glutelinas Ãcidas (0,07 g.100 g-1). O extrato bruto (EB) das sementes apresenta uma grande diversidade de bandas proteicas com predominÃncia de bandas com massa molecular aparente > 45,0 kDa. As sementes de A. cearensis possuem tambÃm alto potencial bioativo, destacando-se as atividades de suas proteÃnas majoritÃrias (globulinas e albuminas) contra o crescimento de bactÃrias e leveduras patÃgenas do homem e de fungos filamentosos fitopatogÃnicos, e atividade contra larvas de Aedes aegypti e Ae. albopictus. A atividade inibitÃria do crescimento de fungos fitopatogÃnicos concentra-se na fraÃÃo F70/90 das albuminas, sendo rica em proteÃnas de baixa massa molecular (< 30 kDa). Assim, pode-se concluir que a F0/90 à uma boa fonte de proteÃna alimentar quando comparada a outras fontes vegetais jà utilizadas pela populaÃÃo. AlÃm disso, as globulinas e albuminas de A. cearensis sÃo fontes promissoras de proteÃnas bioativas que devem ser estudadas mais detalhadamente e em maior grau de pureza.
56

Incorporation of recombinant fibronectin into genetically engineered elastin-based polymers

Balderrama, Fanor Alberto 17 November 2009 (has links)
Cardiovascular disease is the main cause of death in the United States. Many of these conditions require the grafting or bypassing of compromised blood vessels. To this effect, biological vascular grafts (autografts and allografts) are the first line of action. However, when the patient lacks vasculature suitable for grafting use, several synthetic grafting options are available. The search for an inert biomaterial for vascular grafts has proven to be unsuccessful. This makes the interaction taking place on the blood-biomaterial interface critical for the success of the grafts. This thesis introduces a new bio-inspired approach to tackle the mechanical and biological challenges of vascular material design. The hypothesis of this research is that recombinant fibronectin protein can be stably incorporated onto elastin-mimetic polymers to increase endothelialization. Recombinant elastin, designed to recreate the mechanical properties of natural elastin as a candidate material for vascular graft fabrication, was used as a model surface. Recombinant fibronectin-functionalized elastin-mimetic polymer displayed significant improvement in cell adhesion. Quantification of surface bound recombinant fibronectin verified the concentration dependence of this cell adhesive behavior. Modified elastin-mimetic polymer also demonstrated an enhanced ability to support endothelial cell proliferation. Furthermore, the stability of recombinant fibronectin-modified polymers was assessed. These studies provide the foundation for fabricating elastin-mimetic vascular grafts with improved endothelialization and subsequent biological performance.
57

Efeito do consumo de farinha de linha?a (Linum usitatissimum) no crescimento de ratos Wistar e rela??o com a digestibilidade de globulinas e fatores antinutricionais prot?icos

Lopes, Katya Anaya Jacinto 28 June 2007 (has links)
Made available in DSpace on 2014-12-17T14:03:25Z (GMT). No. of bitstreams: 1 KatyaAJ.pdf: 641948 bytes, checksum: 8145771d141a135b5fa6f7f5586cd02d (MD5) Previous issue date: 2007-06-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Linseed is an important oilseed consumed raw as nutritional supplement, that although represents a rich source of nutrients, its nutritional value could be impaired due to the presence of antinutritional factors. In this study, protein fractions from raw linseed flour were extracted and isolated being obtained 12% of albumins, 82% of globulins, 5% of glutelins and 1% of prolamins. These proteins were visualized by SDS-PAGE and albumins showed low molecular mass protein bands around 21 kDa and minor bands, similar to that of trypsin inhibitor; Globulins presented protein bands with high molecular masses, which possibly are constituents of multimeric proteins, such as legumins. After determination of the centesimal composition of raw linseed, it was used as exclusive protein source for young rats to evaluate its effect on animal growth. The results showed negative effects on rat growth (weight gain 73% less than the control group) and reduction of intestinal villus (35%), that could be related with in vitro and in vivo globulin digestibility and proteinaceous antinutritional factors (mammalian digestive enzymes inhibitors and lectins) in albumin fraction. Native globulins showed, by SDS-PAGE, low susceptibility in vitro to trypsin and chymotrypsin, however presented high degradation by pancreatin. Thermal treatment of globulins for 5 and 15 minutes at 100?C improved considerably its digestibility by trypsin and pancreatin. Globulins presented 93.2% in vivo digestibility, similar to the control protein. Albumin fraction had high trypsin inhibition activity (100%) and chymotrypsin inhibition of 28.3%; haemagglutinating activity was not detected. The results of this study indicate the negative action of trypsin inhibitors on animal growth, but can not be discarded its combined action with other antinutritional factors, which could compromise the raw linseed utilization as an alternative food / A linha?a (Linum usitatissimun) ? uma importante oleaginosa consumida crua como suplemento nutricional, que apesar de representar rica fonte de nutrientes, pode ter valor nutricional reduzido devido ? presen?a de fatores antinutricionais. Neste estudo as principais fra??es prot?icas da farinha de linha?a crua foram extra?das e isoladas, sendo obtidos 12% de albuminas, 82% de globulinas, 5% de glutelinas e 1% de prolaminas; o padr?o eletrofor?tico das prote?nas mostrou que as albuminas apresentaram bandas majorit?rias de baixa massa molecular em torno de 21 kDa e menores, indicativas da presen?a de inibidores de tripsina, e nas globulinas foram observadas algumas bandas intensas que provavelmente comp?em uma prote?na multim?rica de alta massa molecular do tipo legumina. Ap?s a obten??o da composi??o centesimal da farinha crua, esta foi usada como fonte exclusiva de prote?nas para ratos rec?m-desmamados, a fim de avaliar seu efeito no crescimento dos mesmos. Os resultados de depress?o do crescimento (ganho de peso 73% inferior ao grupo padr?o) e redu??o no crescimento dos vilos intestinais (35%) levaram ? verifica??o da digestibilidade in vitro e in vivo da fra??o globulina e detec??o de fatores antinutricionais prot?icos (inibidores de enzimas digest?rias de mam?feros e lectinas) na fra??o albumina, como poss?veis fatores delet?rios ao crescimento dos ratos em estudo. As globulinas nativas apresentaram baixa susceptibilidade a digest?o in vitro por tripsina e quimotripsina, no entanto sofreram maior degrada??o pela pancreatina. O aquecimento das globulinas por 5 e 15 minutos a 100?C aumentou consideravelmente a digestibilidade pela tripsina e pancreatina. No experimento de digestibilidade in vivo, a globulina apresentou alta susceptibilidade ? degrada??o pelas enzimas digestivas (93,2%), semelhante ? prote?na padr?o. Na avalia??o da fra??o albumina, esta apresentou alta atividade inibit?ria de tripsina (100%) e, em menor grau, inibi??o de quimotripsina (28,3%), n?o sendo detectada atividade hemaglutinante. Os resultados obtidos s?o indicativos da a??o negativa dos inibidores de tripsina no crescimento dos animais, no entanto n?o se pode descartar a possibilidade de uma a??o sinerg?stica com outros fatores antinutricionais, que comprometem a utiliza??o da linha?a crua como um alimento alternativo
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Etude des interactions dans la formation d'agrégats thermiques mixtes entre globulines de pois et béta-lactoglobuline : application à l'élaboration de gels acides / Study of moleculars interactions in the formation of thermal aggregats beteween pea globulins and beta-lactoglobulin : application to developement of acids gels

Chihi, Mohamed Lazhar 12 July 2016 (has links)
Dans un contexte de diversification des sources protéiques alimentaires, les protéines de pois représentent un ingrédient de choix et pourraient être associées à des protéines laitières comme celles du lactosérum dans la fabrication de nouveaux aliments. Dans ce travail, le comportement d’agrégation thermique (1h à 85°C), préalable à une gélification acide, des globulines de pois (Glob) seules et en mélange avec la β-lactoglobuline (βlg), a été étudié en fonction de la concentration totale en protéine, du ratio massique βlg/Glob et de la force ionique. La caractérisation des agrégats solubles a été réalisée par une combinaison de techniques analytiques telles que la détermination de l’hydrophobicité de surface, la quantification des ponts disulfures, la diffusion dynamique de la lumière (DLS), la chromatographie d’exclusion de taille (SEC-HPLC) et l’électrophorèse SDS-PAGE. La formation d’agrégats mixtes semble être gouvernée par des interactions intermoléculaires non covalentes, mais aussi des liaisons covalentes entre la βlg et les sous-unités de légumine notamment à faible force ionique (5 mM NaCl). Ces dernières semblent contrôler les caractéristiques méso-structurales des agrégats mixtes formés (haut poids moléculaire et diamètre réduit < 110 nm) comparativement aux agrégats formés de globulines seules (diamètre > 150 nm). Le deuxième volet de l’étude concernait la formation de gels acides obtenus par acidification au glucono-δ-lactone, soit à partir des agrégats mixtes solubles caractérisés précédemment, soit à partir de mélanges d’agrégats thermiques de chaque protéine obtenus séparément. Les différents paramètres liés à la cinétique d’acidification et à la gélification (temps et pH de transition sol/gel, propriétés mécaniques par rhéologie dynamique et analyse de la microstructure par Microscopie Confocale à Balayage Laser, capacité de rétention d’eau) ont été évalués. Les résultats démontrent que les agrégats mixtes issus des mélanges thermisés des deux protéines permettent d’obtenir des gels plus élastiques avec une structure fibrillaire plus ordonnée et moins poreuse, avec des caractéristiques proches de celles des gels formés d’agrégats purs de Blg. / In the context of protein source diversification, pea protein is a promising ingredient and may be associated with milk proteins such as whey proteins in the production of new food products. In the present work, the thermal aggregation (85°C - 1 h) of pea globulins (Glob) alone and in admixture with β-lactoglobulin (βlg), prior to acid gelation, was studied as a function of total protein concentration, βlg/Glob weight ratio and ionic strength. The characterization of soluble aggregates was carried out by combining different analytical methods such as surface hydrophobicity determination, disulfide bridge quantification, dynamic light scattering (DLS), size exclusion chromatography (SEC-HPLC) and SDS-PAGE electrophoresis. The formation of mixed aggregates seems to be governed by non-covalent intermolecular interactions, but also by covalent bonds between βlg and legumin subunits at low ionic strength (5 mM NaCl). The latter seem to control the structural features of mixed aggregates (high molecular weight and reduced diameter <100 nm) compared to pure globulin aggregates (diameter > 150 nm). The second part of this work investigated the formation of acid gels by glucono-δ-lactone, obtained either from soluble mixed aggregates such as characterized previously, either from mixtures of thermal aggregates of the two proteins prepared separately. The parameters associated to acidification kinetics and gelation (time and pH at sol/gel transition, mechanical properties by dynamic rheology and microstructure analysis by Confocal Scanning Laser Microscopy, water holding capacity) were evaluated. The results showed that mixed aggregates from heat-treated initial mixtures of the two proteins provides more elastic acid gels with a more regular and less porous fibrillar structure having close characteristics to those of pure βlg gels.

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