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Prediction of the human oral bioavailability by using in vitro and in silico drug related parameters in a physiologically based absorption model

Paixão, P; Gouveia, LF; Morais, JA
Fonte: International journal of pharmaceutics Publicador: International journal of pharmaceutics
Tipo: Artigo de Revista Científica
ENG
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Estimates of the human oral absolute bioavailability were made by using a physiological-based pharmacokinetic model of absorption and the drug solubility at the gastrointestinal pH range 1.5-7.5, the apparent permeability (P(app)) in Caco-2 cells and the intrinsic clearance (Cl(int)) in human hepatocytes suspensions as major drug related parameters. The predictive ability of this approach was tested in 164 drugs divided in four levels of input data: (i) in vitro data for both P(app) and Cl(int); (ii) in vitro data for Cl(int) only; (iii) in vitro data for P(app) only and (iv) in silico data for both P(app) and Cl(int). In all scenarios, solubility was estimated in silico. Excellent predictive abilities were observed when in vitro data for both P(app) and Cl(int) were used, with 84% of drugs with oral bioavailability predictions within a±20% interval of the correct value. This predictive ability is reduced with the introduction of the in silico estimated parameters, particularly when Cl(int) is used. Performance of the model using only in silico data provided 53% of drugs with bioavailability predictions within a±20% acceptance interval. However, 74% of drugs in the same scenario resulted in bioavailability predictions within a±35% interval...

Implantação, evolução, aspectos técnicos e perspectivas da regulamentação técnica de biodisponibilidade relativa e bioquivalência de medicamentos genéricos e similares no Brasil; The implementation, evolution, technical aspects and perspectives regarding technical regulation of relative bioavailability and bioequivalence of generic and similar medicines in brazil

Bueno, Marcia Martini
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/03/2005 PT
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A Política de Saúde no Brasil, que inclui a Política Nacional de Medicamentos, a criação da Agência Nacional de Vigilância Sanitária (ANVISA), a promulgação da Lei de Medicamentos Genéricos, bem como a publicação das Resoluções que estabelecem os critérios técnicos para seu registro, revolucionou o mercado farmacêutico brasileiro na última década, introduzindo vários conceitos como Equivalência Farmacêutica e Terapêutica, Biodisponibilidade e Bioequivalência. Tais conceitos constituem as bases científicas para a implantação dos medicamentos genéricos, aliados à certificação de Boas Práticas de Fabricação e Controle de Qualidade (BPFs). Após cinco anos, os medicamentos genéricos representam cerca de 10% do mercado farmacêutico brasileiro em unidades com redução mínima de 35% no preço do genérico em relação ao medicamento de referência, em função de que o fabricante não necessita investir em estudos clínicos para comprovação da eficácia e segurança, garantidas pela comprovação da equivalência terapêutica com o medicamento de referência. O mercado brasileiro de genéricos é muito atrativo, pois 86% dos fármacos registrados no país não são patenteados e mais de 50% da população brasileira não tem acesso a medicamentos por problemas econômicos. Por outro lado...

Avaliação da biodisponibilidade de hidrocarbonetos policíclicos aromáticos (PAHs) na Baía de Santos através de metabólitos biliares; Evaluation of the Polycyclic Aromatic Hydrocarbons (PAHs) bioavailability in Santos Bay through the biliary metabolites

Barbosa, Ana Cecilia Rizzatti de Albergaria
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 03/07/2009 PT
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Ambientes marinhos adjacentes a centros urbanos, como a Baía de Santos, estão sujeitos à introdução de contaminantes que apresentam caráter tóxico, como os hidrocarbonetos policíclicos aromáticos (PAHs). A biodisponibilidade dos PAHs pode ser avaliada através de biomarcadores de exposição, como metabólitos biliares e atividade da 7-etoxiresorufina-desetilase (EROD). Este trabalho investigou a biodisponibilidade dos PAHs na Baía de Santos através dos metabólitos biliares, usando a atividade EROD como análise auxiliar. Coletas mensais foram realizadas em três regiões da Baía de Santos entre junho e dezembro de 2005. As espécies escolhidas foram: Stellifer rastrifer, Micropogonia furnieri, Nebris microps e Sphoeroides testudineus. Os metabólitos foram analisados através de cromatógrafo a líquido com detector de fluorescência (HPLC/F). A concentração de metabólitos biliares e de atividade EROD variou, respectivamente de 65,5 a 589 g.g-1 de bile e 6,88 a 262 pmol.min-1.mg-1 de proteína. Os níveis de metabólitos de fenantreno e benzo(a)pireno foram menores na espécie N. microps e maiores na S. testudineus, não havendo diferenças significativas entre as espécies para os metabólitos de naftaleno. Não houve diferenças significativas dos metabólitos estudados entre os locais e períodos de coleta. A biodisponibilidade de PAHs na Baía de Santos foi evidenciada pelos metabólitos e confirmada pela atividade EROD.; Marine environments near urban areas...

Avaliação da biodisponibilidade dos HPAs em Mugil curema do Estuário de Santos e de Cananéia através da análise de metabólitos de HPAs em bile de peixes; PAHs bioavailability evaluation in Mugil curema from Santos and Cananeia Estuaries through the analysis of PAHs metabolites in fish bile

Patire, Vinicius Faria
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/11/2010 PT
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Os estuários são o receptáculo final de muitos contaminantes antrópicos, como os hidrocarbonetos policíclicos aromáticos (HPAs), que podem ser tóxicos aos organismos. A biodisponibilidade dos HPAs pode ser avaliada através de biomarcadores de exposição, como os metabólitos biliares. Este trabalho teve como objetivo avaliar a biodisponibilidade do HPAs em peixes da espécie Mugil curema do Estuário de Santos e de Cananéia, através da análise de metabólitos de HPAs em bile de peixes. As coletas no Estuário de Cananéia foram realizadas nos meses de junho e novembro de 2008 e as coletas no Estuário de Santos foram realizadas entre os meses de março e maio de 2009. Os metabólitos foram analisados através de cromatografia líquida com detector de fluorescência (HPLC/F). A concentração de metabólitos biliares totais para o Estuário de Cananéia variou entre 0,91 a 89,97 ?g g-1 de bile, e para o Estuário de Santos variou de 4,68 a 528,43 ?g g-1 de bile. Houve diferença significativa entre os locais estudados. Observou-se também que não houve diferença significativa entre as amostras de machos e de fêmeas. A biodisponibilidade de HPAs foi considerada como baixa para o Estuário de Cananéia e alta para o Estuário de Santos. Valores de referência foram propostos para analise ambiental de metabólitos biliares de HPAs...

Biodisponibilidade de minerais em ratos alimentados com frutanos do tipo inulina; Mineral bioavailability in rats fed inulin-type fructans

Lobo, Alexandre Rodrigues
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/12/2008 PT
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Neste estudo foi avaliado o efeito de frutanos do tipo inulina (FTI) na biodisponibilidade de minerais em ratos, com particular enfoque para o Ca e o Fe. Foram realizados dois ensaios: no primeiro utilizou-se um modelo fatorial 2×2×2, com dois níveis de Fe (0 e 35 mg/kg), Ca (0 e 5 g/kg) e FTI (0 e 100 g/kg) nas rações; no segundo, utilizou-se um modelo de repleção de Hb em ratos anêmicos. As fontes de FTI foram a Raftilose P95 (ensaios 1 e 2), fonte purificada, e a farinha de yacón (FY; ensaio 2); os sais de Fe utilizados foram o Fe4(P2O7)3 (ensaios 1 e 2) e o FeSO4 microencapsulado com alginato (ensaio 2). No primeiro ensaio foram avaliados parâmetros bioquímicos de Fe, concentração de minerais nos ossos, fígado e baço, e parâmetros de resistência e histomorfometria óssea. Após 33 d, não foram observados efeitos na retenção óssea de Ca, porém observou-se maior volume trabecular ósseo e parâmetros histomorfométricos de formação óssea nos animais deficientes em Fe alimentados com os FTI. No segundo ensaio foram determinados parâmetros hematológicos, de biodisponibilidade de Fe, e parâmetros intestinais (balanço mineral; pH, ácidos graxos de cadeia curta e espécies de Fe no conteúdo intestinal). A FY recuperou os animais da deficiência de Fe mais rapidamente do que a Raftilose. Esse efeito ocorreu em função de alterações intestinais provocadas pelo aumento da fermentação desses carboidratos...

Phosphorus bioavailability in diets for growing horses

Oliveira, A. A. M. A.; Furtado, C. E.; Vitti, D. M. S. S.; Resende, F. D.; Cabral Filho, S. L. S.; Tosi, H.; Winkler, B.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 90-95
ENG
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A study of phosphorus (P) metabolism was carried out using 12 month old Brasileiro de Hipismo breed of horses to determine the P bioavailability available from feeds commonly fed to horses in Brazil. Five different diets were formulated to contain approximately equivalent levels of crude protein and digestible energy, as well as to supply at least 22 g P/horse/day (NRC, 1989). All 5 diets contained 40% Bermuda coastal hay plus 60% concentrate. The 5 different concentrates contained: C1 (corn+ cottonseed meal) C2 (corn grain+soybean meal) C3 (corn+sugarcane yeast), C4 (oat+cottonseed meal), and C5 (oat+soybean meal). The radioisotope (32)p was injected with 30 NIB. Blood, feces and urine were collected for 7 days to evaluate endogenous fecal P and true absorption. Analysis of variance of P intake showed differences due to dietary effects (P < 0.05). Concentrate C3 had the lowest intake (79.68 mg/ kg BW). All of the diets produced positive P retention. Absolute values for P concentrations in plasma, urine, feces and endogenous feces did not vary between diets. Values for endogenous fecal P were independent of the level of P intake, so the correlation between P intake and P endogenous was not significant. P bioavailability values were 50.75; 40.98; 43.50; 51.03 and 57.68% for diets C1 through C5...

Biodisponibilidade de fluoreto no plasma sanguíneo e na saliva após a ingestão de água ou alimentos preparados com água fluoretada; Fluoride bioavailability in blood plasma and saliva after ingestion of water or foods prepared with fluoridated water

Amanda Falcão da Silva
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/01/2014 PT
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Há clara evidência da importância da água fluoretada como um meio coletivo de uso de fluoreto (F), responsável pelo decréscimo na incidência de cárie dental. Entretanto, ainda se discute a respeito de seu mecanismo de ação, quer seja relacionado ao aumento da concentração de F na saliva pelo contato com a água fluoretada, quer seja pelo retorno do íon à cavidade bucal, após sua absorção, pela secreção salivar. Além disso, não apenas a ingestão de água fluoretada, mas também de alimentos com ela preparados, tem potencial anticárie, porém desconhece-se se há diferença entre ambas as formas de utilização na capacidade de elevar a concentração salivar de F. Assim, o objetivo deste trabalho foi avaliar a biodisponibilidade de F proveniente da ingestão de água ou de alimentos preparados com água fluoretada. O estudo foi in vivo (n=20), cruzado, duplo cego, e realizado em 4 fases experimentais, nas quais os voluntários ingeriram: água não fluoretada (< 0,01 µg F/mL), água fluoretada (1 µg F/mL), refeição preparada com água não fluoretada ou refeição preparada com água fluoretada. A refeição foi composta por arroz, feijão, carne, vagem, cenoura, suco e gelatina, e o tempo para ingestão foi padronizado em 15 minutos. A dose de F ingerida foi baseada no peso corporal para atingir 0...

Evaluation of iron bioavailability in a mixture of cereals, seeds, and grains ("Human Ration")

Enes,Bárbara Nery; Alves,Natália Elizabeth Galdino; Valdés,Samanta Thomas; Silveira,Carlos Mário Martins; Costa,Neuza Maria Brunoro; Ribeiro,Sônia Machado Rocha; Pires,Shaila Turbay; Martino,Hércia Stampini Duarte
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2014 EN
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Iron bioavailability was evaluated in three mixtures of cereals, seeds, and grains ("Human Ration"): light, regular, and homemade provided to rats. The animals received an iron depletion diet for 21 days, followed by a repletion diet containing 12 mg·kg-1 of iron for 14 days. The hemoglobin regeneration efficiency and the relative biological value did not differ between the light mixture and control group. The iron bioavailability of the light mixture of cereals, seeds, and grains and the control group were 99.99±27.62 and 80.02±36.63, respectively, while the regular and homemade mixtures of cereals, seeds, and grains showed lower iron bioavailability, 50.12±35.53 and 66.66±15.44, respectively; the iron content of the diet with light cereal mixture light was statistically similar to that of the control (ferrous sulfate 99.99±27.62). The high content of tannin (202.81±19.53 mg·100-1) in the diet with the regular cereal mixture may have contributed to its low iron bioavailability. The higher intake of soluble fiber by the animals fed the light mixture (21.15±0.92 g) was moderately correlated (r=0.5712, p=0.0018) with the concentration of propionate in the caecal bulk (65.49±11.08 µmol/g). The short chain fatty acids produced by soluble fiber fermentation...

Bioavailability of the sodium pertechnetate and morphometry of organs isolated from rats: study of possible pharmacokinetic interactions of a ginkgo biloba extract

Moreno,Silvana Ramos Farias; Carvalho,Jorge José; Nascimento,Ana Lúcia; Pereira,Mário; Rocha,Emely Kazan; Diré,Gláucio; Arnobio,Adriano; Caldas,Luiz Querino de Araújo; Bernardo-Filho,Mario
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2005 EN
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Many compounds affect the bioavailability of radiobiocomplexes as radiopharmaceuticals. Ginkgo Biloba extract (EGb) has several effects. The influence of an EGb on the bioavailability of the radiobiocomplex sodium pertechnetate (Na99mTcO4) and on the morphometry of the organs was evaluated. Rats were treated with EGb and Na99mTcO4 was injected. The animals were sacrificed; the radioactivity in the organs was counted. The results showed that EGb altered the Na99mTcO4 bioavailability in the kidneys, liver and duodenum. Morphometric analysis of the organs showed significant alterations (P<0.05), probably caused by metabolites generated by EGb and capable of altering the bioavailability of the Na99mTcO4.

Micronutrient bioavailability: Dietary Reference Intakes and a future perspective1234

Hambidge, K Michael
Fonte: American Society for Nutrition Publicador: American Society for Nutrition
Tipo: Artigo de Revista Científica
EN
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This article provides a review of how the challenge of bioavailability was approached in establishing the Dietary Reference Intakes, with a special focus on folic acid, vitamin B-12, β-carotene, iron, selenium, and zinc, the targeted micronutrients for this workshop. In a future perspective, the necessity of having a clear working definition of bioavailability is emphasized. The bioavailability of micronutrients should be considered, with advantage, under subheadings determined by the broad factors that affect bioavailability. Special emphasis is given to giving greater and specific attention to factors involved in the maintenance of homeostasis. These factors, it is argued, are best considered separately from even a broad definition of bioavailability and have the potential to provide new insights into some micronutrient requirements.

Folate bioavailability: implications for establishing dietary recommendations and optimizing status1234

Caudill, Marie A
Fonte: American Society for Nutrition Publicador: American Society for Nutrition
Tipo: Artigo de Revista Científica
EN
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The addition of folic acid to the US food supply, along with the critical role of folate in certain health outcomes, has intensified worldwide interest in the bioavailability of folate. Bioavailability is a function of absorptive and postabsorptive processes, which in turn are influenced by diet, individuality, and complex diet-host interactions. As such, it is unlikely that a single bioavailability figure will accurately reflect food folate bioavailability from every diet for every person. Although there is broad agreement that naturally occurring food folate is not as bioavailable as folic acid, questions remain as to the extent of these differences, particularly within the context of a whole diet. This article 1) summarizes and integrates bioavailability estimates derived from studies that use whole-diet approaches; 2) highlights the influences of genetics, ethnicity-race, and sex as postabsorptive bioavailability modifiers; and 3) discusses the adequacy of the US folate Recommended Dietary Allowance in achieving folate sufficiency in select subpopulations.

Assessing risk in soils with elevated heavy metal contents: is bioavailability enough?

Hamon, R.; McLaughlin, M.; Bai, L.
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Conference paper
Publicado em //2002 EN
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Total concentrations of metals in soils are a poor indicator of metal toxicity because metals exist in different solid phase forms which can vary greatly in terms of their bioavailability. In an attempt to acknowledge this, risk assessment procedures are moving away from totals-based approaches and towards a measure of bioavailability as an indicator of the risk. For example in aquatic systems, environmental risks are increasingly being predicted using the Biotic Ligand Model, and in soils, the use of neutral salt extractants such as 1.0 M NH4NO3 have been adopted as part of the regulatory tool-kit in several European countries. However, reliance on this approach to assess risk requires an assumption that the bioavailable pool of metals is relatively static, i.e. that metals cannot migrate between different solid-phase pools. Our results demonstrate that in fact small environmental perturbations can result in the ready conversion of apparently non-labile pools of metals into labile forms, suggesting that risk assessment procedures which depend solely on bioavailability are likely to significantly underestimate the potential risk. We have developed a new strategy ("Risk Potential Index" (RPI)) for assessing the latent risk of metals in these non-labile solid-phase pools. We discuss how the RPI in combination with a bioavailability assessment can be used to provide a more appropriate measure of risk.; http://abstracts.co.allenpress.com/pweb/setaceu2002/document/1473; Hamon...

Comparison of in vivo and in vitro methodologies for the assessment of arsenic bioavailability in contaminated soils

Juhasz, A.; Smith, E.; Weber, J.; Rees, M.; Rofe, A.; Kuchel, T.; Sansom, L.; Naidu, R.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
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An in vivo swine assay was utilised for the determination of arsenic (As) bioavailability in contaminated soils. Arsenic bioavailability was assessed using pharmacokinetic analysis encompassing area under the blood plasma–As concentration time curve following zero correction and dose normalisation. In contaminated soil studies, As uptake into systemic circulation was compared to an arsenate oral dose and expressed as relative As bioavailability. Arsenic bioavailability ranged from 6.9 ± 5.0% to 74.7 ± 11.2% in 12 contaminated soils collected from former railway corridors, dip sites, mine sites and naturally elevated gossan soils. Arsenic bioavailability was generally low in the gossan soils and highest in the railway soils, ranging from 12.1 ± 8.5% to 16.4 ± 9.1% and 11.2 ± 4.7% to 74.7 ± 11.2%, respectively. Comparison of in vivo and in vitro (Simplified Bioaccessibility Extraction Test [SBET]) data from the 12 contaminated soils and bioavailability data collected from an As spiked soil study demonstrated that As bioavailability and As bioaccessibility were linearly correlated (in vivo As bioavailability (mg kg−1) = 14.19 + 0.93 · SBET As bioaccessibility (mg kg−1); r2 = 0.92). The correlation between the two methods indicates that As bioavailability (in vivo) may be estimated using the less expensive...

Bioavailability of zinc and copper in biosolids compared to their soluble salts

Heemsbergen, D.; McLaughlin, M.; Whatmuff, M.; Warne, M.; Broos, K.; Bell, M.; Nash, D.; Barry, G.; Pritchard, D.; Penney, N.
Fonte: Elsevier Sci Ltd Publicador: Elsevier Sci Ltd
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
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For essential elements, such as copper (Cu) and zinc (Zn), the bioavailability in biosolids is important from a nutrient release and a potential contamination perspective. Most ecotoxicity studies are done using metal salts and it has been argued that the bioavailability of metals in biosolids can be different to that of metal salts. We compared the bioavailability of Cu and Zn in biosolids with those of metal salts in the same soils using twelve Australian field trials. Three different measures of bioavailability were assessed: soil solution extraction, CaCl2 extractable fractions and plant uptake. The results showed that bioavailability for Zn was similar in biosolid and salt treatments. For Cu, the results were inconclusive due to strong Cu homeostasis in plants and dissolved organic matter interference in extractable measures. We therefore recommend using isotope dilution methods to assess differences in Cu availability between biosolid and salt treatments. Metals in biosolids are not necessarily less bioavailable than their soluble salt.; Diane A. Heemsbergen, Mike J. McLaughlin, Mark Whatmuff, Michael St.J. Warne, Kris Broos, Mike Bell, David Nash, Glenn Barry, Deb Pritchard, and Nancy Penney

Principles and application of an in vivo swine assay for the determination of arsenic bioavailability in contaminated matrices

Rees, M.; Sansom, L.; Rofe, A.; Juhasz, A.; Smith, E.; Weber, J.; Naidu, R.; Kuchel, T.
Fonte: Kluwer Academic Publ Publicador: Kluwer Academic Publ
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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The assessment of arsenic (As) bioavailability from contaminated matrices is a crucial parameter for reducing the uncertainty when estimating exposure for human health risk assessment. In vivo assessment of As utilising swine is considered an appropriate model for human health risk assessment applications as swine are remarkably similar to humans in terms of physiology and As metabolism. While limited in vivo As bioavailability data is available in the literature, few details have been provided regarding technical considerations for performing in vivo assays. This paper describes, with examples, surgical, experimental design and analytical issues associated with performing chronic and acute in vivo swine assays to determine As bioavailability in contaminated soil and food.; Matthew Rees, Lloyd Sansom, Allan Rofe, Albert L. Juhasz, Euan Smith, John Weber, Ravi Naidu and Tim Kuchel

Miniaturisierte direktgekoppelte Analysensysteme zur Strukturaufklärung von Carotinoiden und Bestimmung der Bioverfügbarkeit von markiertem Lutein; Miniaturized hyphenated systems for the structure elucidation of carotenoids and the determination of the bioavailability of labeled lutein

Putzbach, Karsten
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
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In der vorliegenden Arbeit konnte gezeigt werden, dass die gezielte Verwendung von direktgekoppelten Analysensystemen die Beantwortung von sehr komplexen biomedizinischen Fragestellungen ermöglicht. Dabei stellt vor allem die Miniaturisierung der HPLC-NMR-Kopplung zur chromatographischen Trennung und Detektion von sehr kleinen Probenmengen oder geringen Analytmengen in der Probe einen bedeutenden Fortschritt in der instrumentellen Analytik dar. Das für die Bioverfügbarkeitsstudie eingesetzte partiell deuterierte Lutein hingegen zeigt neue Wege und Möglichkeiten auf dem Gebiet klinischer Studien. Die reproduzierbare Herstellung von effizienten Kapillartrennsäulen (250 µm I.D.) stand vor allem am Beginn der Arbeit im Vordergrund. Neben der Optimierung des Slurry-Packprozesses auf die verwendete C30-Trennphase wurde auch eine stabile und universell einsetzbare Endfitting-Technik entwickelt. Durch diese Optimierungen war es nun möglich Kapillartrennsäulen mit einer gleichbleibenden Qualität selber herzustellen, was maßgeblich zum Gelingen dieser Arbeit beitrug. Die gepackten Kapillartrennsäulen zeigten im Vergleich zu klassischen HPLC-Trennsäulen gleichwertige und sogar bessere Trenneigenschaften (Trennstärke, Effizienz). Die Bestimmung von Kenngrößen wie z.B. der Nachweisgrenze...

Bioavailability of Stabilised Ferrous Gluconate with Glycine in Fresh Cheese Matrix: a Novel Iron Compound for Food Fortification

Salgueiro, María; Weill, Ricardo; Boccio, José; Olivares Grohnert, Manuel Alonso; Carmuega, Esteban; Noirt, Florence; Frereux, Marine; Marque, Sebastien; Pizarro Aguirre, Fernando Dagoberto
Fonte: Springer Publicador: Springer
Tipo: Artículo de revista
EN
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Artículo de publicación ISI; Iron fortification of foods continues to be one of the preferred ways of improving the iron status of the population. Dairy product is a common product in the diet; therefore, it is a plausible vehicle for iron fortification. This study aims to investigate the bioavailability of ferrous gluconate stabilised with glycine (FGSG) in a fresh cheese fortified with zinc. The iron bioavailability of fresh cheese fortified with either FGSG and with or without zinc and FGSG in aqueous solution and a water solution of ferrous ascorbate (reference dose) was studied using double radio iron (55Fe and 59Fe) erythrocyte incorporation in 15 male subjects. All subjects presented with normal values for iron status parameters. The geometric mean of iron bioavailability for the water solution of FGSG was 38.2 %, adjusted to 40 % from reference doses (N.S.). Iron bioavailability in fresh cheese fortified with Ca and Zn was 15.4 % and was 23.1 % without Zn, adjusted to 40 % from reference doses (N.S.). The results of the present study show that the novel iron compound ferrous gluconate stabilised with glycine in a fresh cheese matrix is a good source of iron and can be used in iron fortification programmes.

The effects of soil amendments on heavy metal bioavailability in two contaminated Mediterranean soils

Walker, David J.; Clemente Carrillo, Rafael; Roig, Asunción; Bernal Calderón, M. Pilar
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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10 pages, 4 tables, 6 figures.; Two heavy metal contaminated calcareous soils from the Mediterranean region of Spain were studied. One soil, from the province of Murcia, was characterised by very high total levels of Pb (1572 mg kg−1) and Zn (2602 mg kg−1), whilst the second, from Valencia, had elevated concentrations of Cu (72 mg kg−1) and Pb (190 mg kg−1). The effects of two contrasting organic amendments (fresh manure and mature compost) and the chelate ethylenediaminetetraacetic acid (EDTA) on soil fractionation of Cu, Fe, Mn, Pb and Zn, their uptake by plants and plant growth were determined. For Murcia soil, Brassica juncea (L.) Czern. was grown first, followed by radish (Raphanus sativus L.). For Valencia soil, Beta maritima L. was followed by radish. Bioavailability of metals was expressed in terms of concentrations extractable with 0.1 M CaCl2 or diethylenetriaminepentaacetic acid (DTPA). In the Murcia soil, heavy metal bioavailability was decreased more greatly by manure than by the highly-humified compost. EDTA (2 mmol kg−1 soil) had only a limited effect on metal uptake by plants. The metal-solubilising effect of EDTA was shorter-lived in the less contaminated, more highly calcareous Valencia soil. When correlation coefficients were calculated for plant tissue and bioavailable metals...

Bioavailability of phenolic acids

Lafay, Sophie; Gil-Izquierdo, Ángel
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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11 pages, 2 tables, 1 figure.; Two large classes of phenolic acids were comprised in this review: benzoic acid derivatives and cinnamic acid derivatives. They have been found to be very extended in fruits and vegetables at different concentrations. For example, hydroxycinnamic acids concentration was higher than that found for hydroxybenzoic acids. Concerning their consumption, hydroxycinnamic acids provide larger contributions to the total polyphenol intake than benzoic acid derivatives or flavonoids. This phenolic acid intake is led by the coffee intake since it has very rich concentrations in hydroxycinnamic acids. Moreover, several experimental and epidemiological studies report the protection of phenolic acids against various degenerative diseases. However, despite all these interesting attributions and even if phenolic acids are the main polyphenols consumed, their bioavailability has not received as attention as that flavonoids. This concept is an essential step to understand the health-promoting properties of phenolic acids and to serve as tool to design in vivo and in vitro experiments to know their biological properties. Therefore, a compilation of bioavailability data of phenolic acids have been presented here paying attention to the two types of phenolic acid bioavailability...

The bioavailability of zinc and copper in Holstein steers

Nemec, Laura
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
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36.956604%
Gressley, Tanya F.; This study consisted of three experiments to evaluate the bioavailability of mineral supplements. The aim of Experiment 1 was to determine the bioavailability of the organic forms of copper (2-hydroxy-4-methyl-thiobutyrate; HMTBa Cu) and zinc (HMTBa Zn) when administered abomasally. Experiment 2 was performed to determine the bioavailability of two organic forms and one inorganic form of Zn administered abomasally, and measure neutrophil phagocytic ability and L-selectin mRNA. Experiment 3 determined the bioavailability of the same forms of organic zinc and ZnSO4 administered via ruminal infusion. In all experiments, 4 ruminally cannulated Holstein steers, were assigned to a 4 × 4 Latin square design where each period consisted of 6 d rest and 1 d of treatment. Diets consisted of only alfalfa silage and corn silage to minimize dietary Cu and Zn. Jugular catheters were inserted 24 h prior to treatment and blood samples were taken from 0 to 12 h post treatment (Exp. 1) and 0 to 24 hours post treatment (Exp. 2 and 3). Additional blood samples were taken at 0 and 9 h in Experiment 2 for neutrophil measurements. In Experiment 1, a pulse dose of 4 g HMTBa Cu, raised plasma Cu from 0.5-1.5 h following infusion but decreased dry matter intake (DMI). A pulse dose of 8 g HMTBa Zn increased plasma Zn from 1-12 h but also decreased DMI whereas 4 g caused an increase in plasma Zn with no side effects. In Experiment 2...