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Estudo da interação entre as vitaminas lipossolúveis com cádmio e chumbo por ASV em meio orgânico / Study of interaction among fat-soluble with cadmium and lead by ASV In organic mediaSauer, Michele Pokulat 15 September 2006 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work two voltammetric methods were investigated to study the interaction between metals, Cd and Pb, and fat-soluble vitamins (retinol palmitate VA; cholecalciferol VD; α-tocopherol acetate VE; filloquinona - VK). Due to hydrophobic characteristic of these vitamins, the voltammetric measurements were conducted in non aqueous media. In the first method (Method I) acetone was used was used as organic media, tetrabutylamonium iodide (ITBA) 0.2 mol L-1 as electrolyte and an electrode modified reference with double liquid junction - Ag/AgCl/LiCl saturated in ethanol/ITBA 0.02 mol L-1 in N,N - dimetylformamide (DMF). In the second method (Method II) ethanol was used as organic media, acetate buffer pH the 4.6 (in ethanol) as electrolyte and an electrode modified reference with double liquid junction - Ag/AgCl/LiCl saturated in ethanol/acetate buffer pH 4,6 (in ethanol). During the method development the behavior of Cd and Pb in studied conditions was evaluated. Each vitamin was studied individually. Method I was not the more adequate to study the interaction metal-vitamin because in most of the case the vitamin additions caused an increase on the voltammetric signals. Method II presented reduction of the Cd and Pb signals and the anodic shift of peak potentials in presence of the vitamins. The reduction of the signals increased in the order: VK < VD < VE < VA. High peak reduction was observed for Pb with the VA, VE and VD and for Cd with the VK. Measurements of alternating current voltammetry were also investigated to study the adsorption of vitamins on the electrode surface. Comparing the results obtained by the anodic stripping voltammetry with the results by alternated current, it was observed that the variations on the voltammetric signals are related predominantly with to adsorptions of VA and VD while to VE and VK the effect of adsorption was not predominant. / No presente trabalho dois métodos voltamétricos foram investigados para o estudo da interação entre os metais, Cd e Pb, e vitaminas lipossolúveis (palmitato de retinol VA; colecalciferol VD; acetato de α-tocoferol VE; filoquinona - VK). Devido à característica hidrofóbica destas vitaminas, a voltametria foi conduzida em meio orgânico. No primeiro método (Método I) utilizou-se acetona como meio, iodeto de tetrabutilamônio (ITBA) 0,2 mol L-1 como eletrólito e um eletrodo de referência modificado de dupla junção líquida Ag/AgCl/LiCl saturado em etanol/ITBA 0,02 mol L-1 em N,N dimetilformamida (DMF). No segundo método (Método II) utilizouse etanol como meio, o tampão acetato pH 4,6 (em etanol) e o eletrodo de referência modificado de dupla junção líquida Ag/AgCl/LiCl saturado em etanol/Tampão acetato pH 4,6 (em etanol). Na etapa de desenvolvimento dos métodos o comportamento dos metais nas condições estudadas foi avaliado e, após a otimização, estudou-se a modificação dos sinais voltamétricos em função das adições das vitaminas sobre os metais. Cada vitamina foi estudada individualmente. O Método I não foi o mais adequado ao estudo da interação metal-vitamina porque em muitos casos as vitaminas causaram um aumento dos sinais, comportamento contrário ao esperado. O Método II apresentou diminuição dos sinais do Cd e do Pb e ainda o deslocamento anódico dos potencias de pico destes metais na presença de todas as vitaminas. A diminuição dos sinais para Cd e Pb aumentou na ordem: VK < VD < VE < VA, sendo que esta diminuição foi maior para o Pb com VA, VE e VD e maior para o Cd com VK. Medidas por voltametria de corrente alternada foram também realizadas para estudar a adsorção das vitaminas no eletrodo de mercúrio. Comparando os resultados obtidos pela voltametria de redissolução com aqueles de corrente alternada, observou-se que as variações nos sinais voltamétricos estão relacionadas predominantemente ao efeito de adsorção para VA e VD enquanto que para VE e VK o efeito da adsorção não é predominante.
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Investigation of Liquid Trapping Following Supercritical Fluid ExtractionMcDaniel, Lori Heldreth 30 September 1999 (has links)
Supercritical fluid extraction (SFE) is an alternative to traditional extractions with organic solvents. SFE consists of removing the analyte(s) from the matrix, solubilizing them, moving the analyte(s) into the bulk fluid, and sweeping the fluid containing the analyte(s) out of the extraction vessel.
As the fluid leaves the extraction vessel, decompression of the fluid occurs, changing its volume and temperature which can lead to analyte loss.
This work focussed on the trapping process with the restrictor immersed in a liquid after SFE. Experiments compared the effects of trapping parameters on the collection efficiencies of fat-soluble vitamins of similar polarities and structures. The most important variable was the selection of collection solvent and its physical properties, such as viscosity, surface tension and density were found to be important.
Additionally, adding a modifier to the collection solvent in an attempt to change its physical properties and influence collection efficiencies for a polarity test mix was studied. Addition of a modifier can improve collection efficiencies and allow higher collection temperature to be used, but the modifier did not increase trapping recoveries to the extent that collection pressurization did.
The occurrence of a methylation reaction of decanoic acid during the SFE and collection processes, using a methanol modified fluid or collection solvent was investigated. The majority of the reaction occurred during the collection process and the degree of methylation was found to be dependent on temperature, but not on static or dynamic extraction time. When no additional acidic catalyst other than carbon dioxide in the presence of water was present, conversion was limited to about 2%, but was quantitative with an added acidic catalyst.
The last portion of this work involved the application of the SFE process to the extraction and analysis of extractable material in eight hardwood and softwood pulp samples. Grinding the samples increased extractable fatty acid methyl esters (FAMEs) by ten-fold, and in-situ derivatizations resulted in higher FAME recoveries than derivatization after SFE. Liquid trapping enhanced recoveries of lower FAMEs when compared to tandem (solid/liquid) trapping. In-situ acetylations sometimes yielded acetylated glucoses. Large differences in FAMEs concentrations were seen for hardwood samples, but lesser differences were seen for the softwood pulp samples. / Ph. D.
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Εκτίμηση των επιπέδων λιποδιαλυτών βιταμινών στον ορό του αίματος υπερ-παχύσαρκων ασθενών που έχουν υποβληθεί σε βαριατρική επέμβαση τύπου Roux-en-Y γαστρικής παράκαμψης με χολοπαγκρεατική εκτροπήΠαναγή, Ζωή 19 February 2009 (has links)
Η βαριατρική χειρουργική είναι η μόνη διαδικασία που μπορεί να εφαρμοσθεί προκειμένου να επιτευχθεί μόνιμη απώλεια βάρους στην πλειονότητα των ασθενών με υπερ-νοσογόνο παχυσαρκία (130). Οι βαριατρικές χειρουργικές επεμβάσεις ορίζονται ως περιοριστικές, δυσαπορροφητικές ή περιοριστικές και δυσαπορροφητικές ταυτόχρονα. Οι περιοριστικού τύπου χειρουργικές επεμβάσεις έχουν συνδεθεί με αυξημένα ποσοστά αποτυχίας όσον αφορά στην απώλεια βάρους στους υπερ-παχύσαρκους ασθενείς, με αποτέλεσμα να παρατηρείται προοδευτική αύξηση της εφαρμογής βαριατρικών εγχειρήσεων δυσαπορροφητικού τύπου σε όλο τον κόσμο για αυτήν την υπο-ομάδα παχυσαρκίας (100, 108, 130, 131).
Παρά την απώλεια βάρους που μπορεί να επιτευχθεί με αυτές τις χειρουργικές επεμβάσεις, οι μετεγχειρητικές ανεπάρκειες σε πρωτεΐνη, σίδηρο, βιταμίνες, άλατα και λιποδιαλυτές βιταμίνες αποτελούν σύνηθες φαινόμενο και απαιτούν χορήγηση συμπληρωμάτων προκειμένου να διατηρηθούν σε φυσιολογικά επίπεδα. Οι ανεπάρκειες αυτές οφείλονται στη δυσαπορρόφηση που προκύπτει από τη χειρουργική παράκαμψη τμημάτων του γαστρεντερικού σωλήνα, όπου τα διάφορα διατροφικά συστατικά απορροφούνται (118).
Αν και αναμενόμενες, οι μεταβολικές ανωμαλίες πολύ συχνά δε διαγιγνώσκονται ή υποεκτιμούνται. Τα βιβλιογραφικά δεδομένα που αναφέρονται στις διατροφικές ανεπάρκειες που παρατηρούνται μετά τις βαριατρικές εγχειρήσεις είναι περιορισμένα, και απαρτίζονται από αναφορές σε μεμονωμένα περιστατικά ασθενών (124-126), από επισκοπήσεις αποτελεσμάτων παλαιότερων ερευνών (118, 132) και από περιστασιακές προοπτικές μελέτες (118, 131). Αν και υπάρχουν αρκετές πληροφορίες για διατροφικά συστατικά, όπως είναι η πρωτεϊνη, ο σίδηρος, η βιταμίνη Β12, το φυλλικό οξύ και το ασβέστιο (118, 131), τα στοιχεία που παρατίθενται για τις λιποδιαλυτές βιταμίνες είναι ελάχιστα και ελλιπή. Αυτό οφείλεται σε σημαντικό βαθμό στη δυσκολία απομόνωσης και προσδιορισμού των λιποδιαλυτών βιταμινών από τον ορό του αίματος, διαδικασία αρκετά επίπονη, δαπανηρή και χρονοβόρα. Οι περισσότεροι χειρούργοι προσπαθούν να ελέγξουν με έμμεσο τρόπο τα επίπεδα των λιποδιαλυτών βιταμινών, όπως για παράδειγμα με παρακολούθηση των τιμών της PTH, άνοδος της οποίας συνηγορεί σε πιθανή ελάττωση των επιπέδων της βιταμίνης D3 (133), ή με παρακολούθηση του χρόνου προθρομβίνης των ασθενών ανά τακτά χρονικά διαστήματα, αύξηση του οποίου μπορεί να υποδεικνύει την ελάττωση των επιπέδων της βιταμίνης Κ (134). Στις περισσότερες περιπτώσεις, η ανεπάρκεια των λιποδιαλυτών βιταμινών γίνεται αντιληπτή μόνο από τις κλινικές της εκδηλώσεις ( 124, 125, 135).
Σκοπός αυτής της εργασίας ήταν η προεγχειρητική εκτίμηση των επιπέδων λιποδιαλυτών βιταμινών στο αίμα υπερ-παχύσαρκων ασθενών που υποβλήθηκαν σε δυσαπορροφητική επέμβαση κατά Roux-en-Y γαστρικής παράκαμψης με χολοπαγκρεατική εκτροπή, καθώς και η μετεγχειρητική παρακολούθησή τους για ένα έτος, ώστε να καταστεί δυνατή η άμεση εκτίμηση της κατάστασης των ασθενών ως προς τα αποθέματα βιταμίνης A, D E και Κ και να διερευνηθεί κατά πόσο η χειρουργικά προκαλούμενη δυσαπορρόφηση λίπους επηρεάζει την απορρόφησή και τα επίπεδα των λιποδιαλυτών βιταμινών στο αίμα. / Background: Bariatric surgery seems to be the only effective approach for the long-term management of morbid obesity. Weight loss after Roux-en-Y Gastric Bypass with Biliopancreatic Diversion (RYGBP/BPD) is mainly due to decreased calorie absorption secondary to fat malabsorption. Fat malabsorption may also cause essential fat-soluble vitamin deficiencies which may become clinically significant if not recognized and properly treated. Prevention of these vitamin deficiencies includes both supplementation and routine measuring of serum values. In this work, an investigation was undertaken to examine preoperative and short-term (1 year) postoperative levels of fat-soluble vitamins in patients undergoing RYGBP/BPD.
Methods: Study population consisted of 15 super-obese (BMI>50kg/m2) patients who had undergone RYGBP/BPD. Routine postoperative daily supplementation consisted of 4000 IU (1200 μg) vitamin A, 2000 IU (50 μg) vitamin D3, 10 mg vitamin E and 2000 mg calcium. Preoperative and postoperative serum levels of fat-soluble vitamins A, D3, 25(OH)D3, E, K2, were measured in these patients by HPLC.
Results: All vitamin levels tended to decrease with time after RYGBP/BPD operation despite that all patients were taking daily multivitamin supplements p.o. postoperatively. One year after the bariatric operation, a significant decrease (P<0.05) in D3, 25(OH)D3, E and K2 levels was observed compared to the preoperative levels. This decrease led to vitamin deficiency one year after the operation, the incidence of which was 7,7% for vitamin A, 41.7% for vitamin 25(OH) D3 and 27.3% for K2. Concerning vitamin E, all patients had lower than normal levels even before operation and the deficiency insisted even after operation, despite the administration of vitamin supplements to the patients. The low preoperative serum vitamin E levels in the patients confirmed that obese individuals are at high risk of vitamin E deficiency.
Conclusions: The serum levels of fat-soluble vitamins A, D, E and K decreased with time following RYGBP/BPD operation in morbidly obese patients, despite that the patients received vitamin supplements postoperatively. The results of our study indicate that patients undergoing the RYGBP/BPD operation need long-term postoperative monitoring of serum fat-soluble vitamin levels. This will facilitate the administration of appropriate doses of multivitamin supplements to these patients, preventing vitamin deficiency to become of clinical significance.
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Perfil de micronutrientes em pacientes com fibrose cística acompanhados no HC da Unicamp / Micronutrient profile in patients with cystic fibrosis accomnpanied on the HC UnicampBarbosa, Claudia Regina, 1974- 21 August 2018 (has links)
Orientador: Antonio Fernando Ribeiro / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T12:18:48Z (GMT). No. of bitstreams: 1
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Previous issue date: 2012 / Resumo: A Fibrose Cística (FC) é a doença de maior prevalência dentre as doenças hereditárias incidentes nos indivíduos caucasóides. A doença é progressiva e apresenta como manifestação clínica à obstrução respiratória crônica, infertilidade masculina e deficiência de ganho de peso pelo dano ao pâncreas exócrino. A maioria dos pacientes tem níveis elevados de eletrólitos no suor. O objetivo do presente trabalho consistiu na importância do diagnóstico precoce das repercussões nutricionais sobre a evolução e prognóstico da doença, pois avaliou o perfil nutricional dos micronutrientes (vitaminas lipossolúveis e oligoelementos) em pacientes com Fibrose Cística atendidos no ambulatório de Fibrose Cística do Hospital das Clínicas da UNICAMP. Foram estudados 86 pacientes, além de 34 voluntários saudáveis para o grupo controle. Amostras de sangue foram coletadas para quantificação dos parâmetros bioquímicos séricos, por métodos enzimáticos colorimétricos. As vitaminas lipossolúveis foram determinadas após seu isolamento por cromatografia líquida rápida de proteínas (High Protein Liquid Chromatograpy-HPLC).Observamos que para a análise dos níveis séricos das vitaminas lipossolúveis e dos oligoelementos na população estudada mostrou valores adequados, exceto para a vitamina A e E, mesmo com uma dieta insuficiente para elementos / Abstract: The Cystic Fibrosis (FC) is the illness of bigger prevalence amongst the incident hereditary illnesses in the caucasian subjects. The illness is gradual and presents as clinical manifestation to the chronic respiratory blockage, masculine infertility and deficiency of profit of weight for the damage to the exocrine pancreas. The majority of the patients has high electrolyte levels in the sweat The present work consisted of the importance of the precocious diagnosis of the nutrition repercussions on the evolution and prognostic of the illness, therefore it evaluated the nutritional profile of the micronutrients (fat-soluble vitamins and oligoelements) in patients with Cystic Fibrosis taken care of in the clinic of Cystic Fibrosis of the Hospital of the Clinics of the UNICAMP. We studied 86 patients and 34 healthy volunteers in the control group. Blood samples were collected for measurement of serum biochemical parameters for enzymatic colorimetric methods. Soluble vitamins were determined after their isolation by fast protein liquid chromatography (High Protein Liquid Chromatograpy-HPLC).We observe that for the analysis of the serum levels of fat-soluble vitamins and the oligoelements in the studied population it showed adjusted values, except for the vitamin A and the E, exactly with a insufficient diet for elements / Doutorado / Saude da Criança e do Adolescente / Doutora em Saúde da Criança e do Adolescente
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Avaliação qualitativa em interface óleo/água do potencial antioxidante de vitaminas lipossolúveis pela técnica da voltametria de onda quadradaSardinha, Eduardo dos Santos January 2015 (has links)
Orientador: Prof. Dr. Hugo Barbosa Suffredini / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência & Tecnologia - Química, 2015. / Este trabalho buscou aplicar a tecnica de voltametria de onda quadrada em uma interface envolvendo dois liquidos imisciveis, sendo uma fase oleosa, contendo vitaminas lipossoluveis e outra aquosa, formada por solucoes-tampao em dois valores de pH (5,5 e 7,0). Foram realizados testes de interacao entre o tocoferol (lipossoluvel) e o acido ascorbico (hidrossoluvel adicionada a fase aquosa), de aplicacao direta da tecnica em um balsamo pos-barba e de microscopia eletroquimica de varredura. Com o uso de eletrodos de carbono
impresso, foram obtidos valores numa escala relativa de potenciais de oxidacao para a vitamina A proximos de 0 V, no caso da vitamina K de -0,1 V e para a vitamina E os potencias foram de 0,1 V aproximadamente (todos em relacao ao potencial de Ag). Em relacao ao teste do balsamo, foi identificado um pico com o perfil e o potencial de oxidacao caracteristico do ¿¿-tocoferol, enquanto que na avaliacao da interacao entre as vitaminas E e C na interface,
dados comprovaram o descrito na literatura. / This work applied the square wave voltammetry technique on an interface between two immiscible liquids, one being the oily one, containing the fat soluble vitamins and another one, aqueous, corresponding to a buffer solution on two pH values 5,5 and 7,0. Besides it, tests of tocopherol (vitamin E, fat soluble) and ascorbic acid (Vitamin C, water soluble interaction, a direct application on an after shaving balm and scanning microscopy electrochemistry tests were carried out. By applying screen printed carbon electrodes, the
relative oxidation potential to Vitamin A was determined as being next to 0 V. In the case of vitamin K the oxidation potential was measured as -0,1 V and to vitamin E, the values were close to 0,1 V (all potential data was measured versus Ag potential). Concerning the balm, a peak was detected exactly with the same profile and potential of the á-tocopherol. Also, the interaction between vitamins C and E was measured directly on the interface with results near from what was expected by the literature.
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