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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.
81

HILIC-MS analysis of protein glycosylation using nonporous silica

Rachel E. Jacobson (5929808) 16 January 2019 (has links)
The objective of this research is to develop and apply a HILIC UHPLC stationary phase that allows for separation of intact glycoproteins. In Chapter 1 I give an overview of the problems of current glycosylation profiling with regards to biotherapeutics, and my strategy to separate the intact glycoprotein with HILIC. Chapter 2 describes the methods used to produce the nonporous packing material and stationary phase. In Chapter 3 I describe previous work in developing a HILIC polyacrylamide stationary phase, and further improvements I have made. Chapter 4 describes development of an assay in collaboration with Genentech of therapeutic mAb glycosylation. In Chapter 5, I show HILIC-MS of digested ribonuclease B as a beginning step to analyze glycosylated biomarkers.
82

Methodologies to assess the fate of polar organic compounds in aquatic environments

Magnér, Jörgen January 2010 (has links)
Polar organic compounds (POCs) are chemicals with polar functional groups in their structure. The functional groups make the compounds hydrophilic and less prone to partition with biota. However, the knowledge of their fate is limited due to difficulties associated with their measurements. Although, the persistence of POCs in the environment is generally low, they are considered to be semi-persistent compounds due to their continuous introduction to the environment via wastewater. Studies have shown that complex mixtures of POCs of different classes may have synergistic toxic effects on biota at environmental concentration levels. Therefore, it is important to develop analytical methods in order to establish the occurrence and fate of POCs in aquatic environments. In Study I, a positive correlation between the sorption of a novel poly(ethylene-co-vinyl acetate-co-carbon monoxide) (PEVAC) material and the theoretical logarithmic dissociation partition coefficient (Log D) for seven POCs was observed. The PEVAC material showed an enhanced sorption of the POCs compared to the silicone material. Study II, demonstrated that the PEVAC sampler assess the freely dissolved concentration of POCs in aquatic environments. The results showed that the PEVAC polymer is an attractive alternative to silicone for mimicing the biological uptake of POCs in aquatic environments. Additionally, Study II showed that total extraction is appropriate for determination of the freely dissolved concentration of uncharged POCs with Log KOW < 2.67 in natural water. In study III, a novel bag-solid phase extraction (bag-SPE) technique was compared to a conventional SPE-technique. Despite that the extraction efficiencies for POCs in wastewater were lower using the bag-SPE method, the two methods showed similar detection limits due to the lower ion-suppression experienced with the bag-SPE. In study IV the bag-SPE method was further developed with the aim of lowering the detection limits for POCs. Detection limits (LOD) below 13 ng/L showed that the bag-SPE method was suitable for determination of POCs in surface sea water. / This research was financially supported by European Union (European Commission, FP6 Contract No. 003956) “Novel Methods for Integrated Risk Assessment of Cumulative Stressors in the Environment” (NoMiracle) and by the Swedish research council Formas.
83

The development of mass spectrometry-based methodologies for the high throughput quantitation of peptides in biological matrices

Howard, James W. January 2018 (has links)
The aim of this research was the development of mass spectrometry-based methodologies for the high-throughput quantitation of peptides in biological matrices. Glucagon and GLP-1, which are of interest as biomarkers and in the development of therapeutics, were chosen as model peptides. Immunoassays that are traditionally used to quantify these often perform poorly; therefore, necessitating the development of alternative methodologies. Application of mass spectrometry-based methodologies to these analytes has, however, been limited, primarily due to sensitivity challenges, but also due to analytical challenges associated with their endogenous nature and instability in biological matrices. Chapter 2 describes the development and qualification of the first liquid-chromatography coupled tandem mass spectrometry (LC-MS/MS) method for the quantitation of endogenous glucagon from human plasma. A novel 2D extraction procedure was developed to ensure robustness and sensitivity, whilst a novel surrogate matrix quantitation strategy took into account the endogenous nature of the analyte. A lower limit of quantitation (LLOQ) of 25 pg/mL was qualified, which was a considerable improvement over that previously reported in the literature (250 pg/mL) for a LC-MS/MS method. Clinical samples were cross-validated against a conventional radioimmunoassay (RIA), and similar pharmacokinetic (PK) profiles resulted, demonstrating that the methods were complementary. In Chapter 2 glucagon instability in biological matrix was noted. To characterise this further, in Chapter 3 in vitro glucagon metabolites were identified using high-resolution mass spectrometry (HRMS). Metabolites observed by others (glucagon19-29, glucagon3 29 and [pGlu]3glucagon3 29) in alternative matrices were identified, alongside novel metabolites (glucagon20-29 and glucagon21-29). Cross-interference of these metabolites in immunoassays may help to explain their poor performance, whilst knowledge of metabolism may also aid the development of future stabilisation strategies. The method developed in Chapter 2 was refined in Chapter 4 to improve sensitivity, robustness and throughput, and to add GLP-1 as a secondary analyte. The sensitivity achieved (glucagon: 15 pg/mL LLOQ, GLP-1: 25 pg/mL LLOQ) is the highest reported for both peptides for an extraction avoiding immunoenrichment. Specificity of endogenous glucagon quantitation was assured using a novel approach with a supercharging mobile phase additive to access a sensitive qualifier transition. A cross-validation against established immunoassays using physiological study samples demonstrated some similarities between the methods. Differences between the immunoassay results exemplified the need to develop alternative methodologies. The resulting LC-MS/MS method is considered a viable alternative to immunoassays, for the quantitation of endogenous glucagon, dosed glucagon and/or dosed GLP-1 in human plasma.
84

Vlastnosti komplexů aminojílu a biologicky aktivních látek / Properties of aminoclay complexes and biologically active substances

Dušek, Jakub January 2020 (has links)
This paper builds on previous research of aminoclay complexes in undergraduate studies. Theoretical part deals with study of current problems of aminoclay complexes with bioactive substances and the choice of substances for complexing with aminoclay. The experimental part consists of preparation of aminoclay complexes with selected bioactive agents at various concentrations. Verification of binding of bioactive agents to the aminoclay matrix was performed by Elemental Analysis (EA) and Fourier-transform infrared spectroscopy (FT-IR). For finding of the bound amount of bioactive substance were used the Ultra Performance Liquid Chromatography (UPLC®) and analysis of the cytotoxic properties of the formed complexes by used by the MTT assay. The main motivation of this study is to create new complexes with improved characteristics that would replace existing forms of substances used in pharmaceutical and biomedical applications.
85

Différenciation du sirop d'érable à défaut de saveur de type bourgeon (√R5) du sirop d'érable à saveur sans défaut (REG) à l'aide de SPME-GC/MS et UPLC-QTOF-MS/MS

Beniani, Issraa 01 1900 (has links)
L’industrie des produits de l’érable est particulièrement importante en Amérique du Nord. Elle est touchée par un phénomène naturel qui se produit en fin de saison de récolte. Il s’agit de l’altération du goût du sirop ; un goût fort désagréable se développe et se nomme goût de bourgeon vu qu’il coïncide au bourgeonnement des feuilles d’érable. Des coûts et du temps sont impliqués à sa récolte et sa production. Cependant, un sirop d’érable avec un goût de bourgeon est vendu à moindre prix. Il constitue donc une perte potentielle d'argent pour les producteurs. Au fil du temps, ils ont appris à se fier à des signes distincts de la nature pour déterminer le début du bourgeonnement. Néanmoins, il est important de le détecter hâtivement pour les producteurs et de mieux comprendre les changements moléculaires associés au défaut de saveur de type bourgeon. Plusieurs travaux sur les produits de l’érable ont été effectués durant le dernier siècle, mais ce n’est que récemment que des projets de recherche sont centrés sur le goût de bourgeon. La détection de celui-ci est certes importante, mais il y est aussi question de mieux connaître la variation de la composition du sirop ou de la sève d’érable, afin de mieux comprendre le phénomène. Tel que décrit dans l’introduction de ce mémoire, on connaît maintenant mieux la composition du sirop d’érable, même que quelques solutions ont été proposées à notre problème, mais beaucoup de questions restent sans réponse que ce mémoire tentera de résoudre. C'est dans ce contexte que cette étude se pose. En visant à identifier les molécules responsables du défaut de goût de type bourgeon que l’on peut retrouver dans le sirop d’érable, nous espérons aider à mieux cibler le problème et à mieux comprendre le métabolisme et, éventuellement, comprendre comment ce goût se développe. Dans un second temps, la découverte de molécules pas encore rapportées, au meilleur de notre connaissance, comme étant présentes dans le sirop d’érable est aussi visée, sans égard à la classification du sirop. Les travaux de ce mémoire contribueront, ultimement, à trouver une façon d’empêcher la formation de ce goût et surtout un moyen de l’éliminer. Pour ce, une première partie correspondant à l’analyse des composés volatils a été effectuée par SPME et GC-MS sur 78 échantillons de sirop d’érable. L’analyse statistique des résultats par PCA cible 42 composés et associe chacun d’entre eux au sirop d’érable avec le défaut de saveur ou alors au sirop sans défaut de saveur. Parmi elles, seules 36 ont pu être identifiées par leurs spectres de masse. La seconde partie correspond à l’analyse des composés non volatils par UPLC-QTOF et UPLCMS/MS. La méthode a été optimisée pour cibler les molécules relativement apolaires par rapport aux sucres et aux acides aminés présents dans le sirop d’érable. Au total, 20 échantillons de sirop ont été analysés, dont 10 à défaut de saveurs de type bourgeon et 10 sans défaut. Pour cette partie, l’analyse de composantes principales a encore une fois été utilisée pour classer les types de sirop à l’étude selon les composés détectés. Ainsi, le mémoire avance les connaissances moléculaires liées à l’émergence du défaut de bourgeon dans le sirop d’érable. / The maple products industry is particularly important in North America. It is affected by a natural phenomenon that occurs at the end of the harvest season. It’s the alteration of the taste of the syrup; a very unpleasant taste develops and is called buddy flavour since it coincides with the budding of maple leaves. Costs and time are involved in its harvest and production. When maple syrup is associated with the buddy taste, its commercial value is lower. Therefore, it contributes to a loss of money for producers. Over time, they have learned to rely on distinct signs from nature to determine the onset of budding. However, methods are needed to detect it and research is needed to better understand the molecular changes in maple syrups. Several research projects on maple products have been carried out during the last century, but it is only recently that research projects have focused on the buddy flavour. They focus on determining the variation in the composition of maple syrup or sap, but also on better understanding of the phenomenon. We now know more than ever about the composition of maple syrup, on top of that some solutions have been proposed to our problem, but many questions remain unanswered and it is obvious that there is still so much to discover. It is in this context that this study arises. By aiming to identify the molecules responsible for the buddy flavour defects that can be found in maple syrup, we hope to help on targeting the problem and better understanding the metabolism of maple trees and, eventually, how the buddy taste develops. Secondly, it is aimed at discovering molecules not yet reported, to the best of our knowledge, as being present in maple syrup regardless of the classification of the syrup. This will contribute, ultimately, in finding a way to prevent the formation of this taste and a way to eliminate it. Thus, the first part of this master’s thesis corresponds to the analysis of volatile compounds by SPME and GC-MS on 78 maple syrup samples. Statistical analysis of the results targets 42 compounds and associates them with either maple syrup with flavour defects or with maple syrup with regular flavour maple syrup. Among these, 36 molecules could be identified by mass spectrometry. To extract correlations from our data, the principal component analysis (PCA) ensued. The second part corresponds to the analysis of non-volatile compounds by UPLC QTOF and UPLC-MS/MS. The method has been optimized to target molecules that are relatively apolar compared to sugars and most of the amino acids present in maple syrup. A total of 20 syrup samples were analyzed, including 10 with bud-like flavour defects and 10 with no defects. For both parts, PCA was once again used to determine which types of syrup under study are the compounds associated with. Taken together, the results presented in this master’s thesis advances knowledge on the molecular origins of the buddy flavour defect in maple syrups.
86

A scientific investigation of the immunomodulatory properties of an indigenous plant, Sutherlandia frutescens

Gonyela, Odwa 01 1900 (has links)
Traditional medicines prepared from Sutherlandia frutescens are used to manage diseases including HIV and cancer. This study aimed at isolating and identifying biologically active compounds isolated from S. frutescens. Sutherlandia frutescens plants were collected in Petrusburg and Paarl. Powdered plant material was extracted using ethanol or water and their metabolite composition was compared using UPLC-MS. A novel cycloartane, an acetylated variant of this compound as well as a Sutherlandioside B triterpenoid was isolated and characterised using chromatographic and analytical techniques such as NMR and UPLC-MS. Preliminary biological studies were conducted to assess the activity of plant extracts on cell toxicity, herpes virus replication and cytokine expression. The results of this study suggest that aqueous extracts from S. frutescens do not appear to be cytotoxic or show anti-herpetic activity, but may activate the immune system by increasing expression of IL-6, IL-10 and TNFα. Further research should be conducted to confirm and optimise these results. / Life and Consumer Sciences / M. Sc. (Life Science)
87

Caractérisation des propriétés anti-inflammatoires et anticancéreuses de la plante Agelanthus dodoneifolius (DC) Polh. & Wiens (Loranthaceae) utilisée en médecine traditionnelle au Burkina Faso / Characterization of anti-inflammatory and anticancer properties of Agelanthus dodoneifolius (DC) Polh. & Wiens (Loranthaceae) used in traditional medicine plant in Burkina Faso

Boly, Raïnatou 07 January 2012 (has links)
Le présent travail a porté sur l’évaluation des propriétés anti-inflammatoires et anticancéreuses de Agelanthus dodoneifolius (Loranthaceae), communément appelée «gui africain». Cette plante hémiparasite est utilisée en médecine traditionnelle africaine pour le traitement de pathologies chroniques telles que l’asthme, l’hypertension, des gastroentérites et le cancer. Actuellement, les maladies chroniques représentent un problème mondial de santé publique. En effet, elles constituent la première cause de mortalité dans le monde surtout dans les pays à revenu faible ou intermédiaire. <p><p>Cette étude a été réalisée dans le but d’apporter une validation scientifique quant à certaines utilisations traditionnelles de Agelanthus dodoneifolius. <p>Pour évaluer l’effet anti-inflammatoire de Agelanthus dodoneifolius, nous avons testé les différentes fractions de la plante sur la production des espèces réactives de l’oxygène, la libération et l’activité spécifique de la myéloperoxydase (MPO), enzyme libérée par le neutrophile au cours de la phagocytose pour détruire les microorganismes. L’identification et la quantification des composés a été faite grâce à une combinaison des méthodes chromatographiques, spectrophotométriques et spectrométriques. L’activité anticancéreuse de Agelanthus dodoneifolius a consisté, d’abord, à déterminer l’effet d’inhibition de croissance de diverses fractions de la plante, de la quercétine ainsi que de ses dérivés sur des lignées cellulaires cancéreuses. Nous avons ensuite déterminé les effets de la quercétine sur l’activité de plus de 300 kinases. <p><p>Les résultats obtenus montrent qu’Agelanthus dodoneifolius est capable de moduler les activités biologiques des neutrophiles. En effet, le décocté aqueux et les fractions organiques de la plante inhibent de manière dose-dépendante la production des espèces réactives de l’oxygène, la dégranulation du neutrophile et l’activité spécifique de la myéloperoxydase. Nous avons pu identifier et quantifier dix composés polyphénoliques dont quatre acides phénoliques :l’acide gallique, l’acide coumarique, l’acide chlorogénique et l’acide ellagique et six flavonoïdes :la quercétine, le kaempférol, la catéchine, l’isoquercitrine ou quercétine 3-O-glucoside, la rutine et la miquelianine ou quercétine-3-O-glucuronide. <p>Concernant l’activité anticancéreuse, les résultats montrent que seules les fractions à l’éther diéthylique et à l’acétate d’éthyle ont une activité antiproliférative. La quercétine a des effets inhibiteurs de croissance, cytostatiques et présente un large spectre d’activité sur plusieurs kinases surexprimées dans certains cancers. <p><p>En conclusion, l’ensemble de ces résultats constitue des bases scientifiques qui pourraient justifier certaines utilisations traditionnelles de Agelanthus dodoneifolius. <p>À notre connaissance, cette étude est la première à évaluer d’une part l’effet, in vitro, des différentes fractions de Agelanthus dodoneifolius sur des neutrophiles stimulés et sur la MPO et d’autre part l’effet inhibiteur de croissance de lignées cellulaires cancéreuses par certaines fractions de la plante. En outre, cette étude a permis pour la première fois d’identifier et de quantifier des composés polyphénoliques dans Agelanthus dodoneifolius. Les nombreuses propriétés de ces composés, notamment celles anti-inflammatoires et anticancéreuses, peuvent expliquer en partie les résultats reportés dans ce travail.<p><p>This work focused on evaluating anti-inflammatory and anticancer activities of Agelanthus dodoneifolius (Loranthaceae), commonly called "African mistletoe". This plant is used in African traditional medicine for the treatment of chronic conditions such as asthma, hypertension, gastroenteritis and cancer. Currently, chronic diseases are a global public health problem. Indeed, they are the leading cause of death worldwide, especially in countries with low and middle income.<p>The study was conducted to provide scientific validation for some traditional uses of Agelanthus dodoneifolius.<p><p>To characterize the anti-inflammatory activity of Agelanthus dodoneifolius, we tested the different fractions of the plant on reactive oxygen species production, release and the specific activity of myeloperoxidase, an enzyme released by neutrophils during phagocytosis to destroy microorganisms. The identification and quantification of compounds were made through a combination of chromatographic, spectrophotometric and spectrometric techniques. The anticancer activity of Agelanthus dodoneifolius consisted, first, to determine, the antiproliferative effect of fractions of the plant, quercetin and its derivatives on cancer cell lines. Then, we determined the effects of quercetin on the activity of more than 300 kinases.<p><p>The results show that Agelanthus dodoneifolius is capable of modulating the biological activities of neutrophils. In fact, the decoction aqueous and organic fractions of the plant inhibited in a dose-dependent manner the production of reactive oxygen species, degranulation of neutrophils and specific activity of myeloperoxidase. <p>We were able to identify and quantify ten polyphenolic compounds including four phenolic acids: gallic acid, coumaric acid, chlorogenic acid and ellagic acid and six flavonoids: quercetin, kaempferol, catechin, isoquercitrin or quercetin 3-O-glucoside, rutin and miquelianin or quercetin-3-O-glucuronide.<p>Regarding the anticancer activity, the results show that only fractions with diethyl ether and ethyl acetate have antiproliferative activity. Quercetin has antiproliferative and cytostatic effects and presents a broad spectrum of activity on several kinases overexpressed in certain cancers.<p><p>In conclusion, all these findings are scientific basis that could justify some traditional uses of Agelanthus dodoneifolius. To our knowledge, this is the first study to evaluate the effect firstly, by in vitro tests, of the different fractions of Agelanthus dodoneifolius on stimulated neutrophils and the MPO and secondly the growth inhibitory effect of cancer cell lines by certain fractions. Also, this study is the first to identify and quantify the phenolic compounds in Agelanthus dodoneifolius. The many properties of these compounds, including anti-inflammatory and anticancer, may partly explain the results reported in the present work. / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished
88

Phytochemical investigation of Acronychia species using NMR and LC-MS based dereplication and metabolomics approaches / Etude phytochimique d’espèces du genre Acronychia en utilisant des approches de déréplication et métabolomique basées sur des techniques RMN et SM

Kouloura, Eirini 28 November 2014 (has links)
Les plantes médicinales constituent une source inexhaustible de composés (des produits naturels - PN) utilisé en médecine pour la prévention et le traitement de diverses maladies. L'introduction de nouvelles technologies et méthodes dans le domaine de la chimie des produits naturels a permis le développement de méthodes ‘high throughput’ pour la détermination de la composition chimique des extraits de plantes, l'évaluation de leurs propriétés et l'exploration de leur potentiel en tant que candidats médicaments. Dernièrement, la métabolomique, une approche intégrée incorporant les avantages des technologies d'analyse moderne et la puissance de la bioinformatique s’est révélé un outil efficace dans la biologie des systèmes. En particulier, l'application de la métabolomique pour la découverte de nouveaux composés bioactifs constitue un domaine émergent dans la chimie des produits naturels. Dans ce contexte, le genre Acronychia de la famille des Rutaceae a été choisi sur la base de son usage en médecine traditionnelle pour ses propriétés antimicrobienne, antipyrétique, antispasmodique et anti-inflammatoire. Nombre de méthodes chromatographiques modernes, spectrométriques et spectroscopiques sont utilisées pour l'exploration de leur contenu en métabolites suivant trois axes principaux constituant les trois chapitres de cette thèse. En bref, le premier chapitre décrit l’étude phytochimique d’Acronychia pedunculata, l’identification des métabolites secondaires contenus dans cette espèce et l'évaluation de leurs propriétés biologiques. Le deuxième chapitre vise au développement de méthodes analytiques pour l'identification des dimères d’acétophénones (marqueurs chimiotaxonomiques du genre) et aux stratégies utilisées pour la déréplication de ces différents extraits et la caractérisation chimique des composés par UHPLC-HRMSn. Le troisième chapitre se concentre sur l'application de méthodologies métabolomique (RMN et LC-MS) pour l'analyse comparative (entre les différentes espèces, origines, organes), pour des études chimiotaxonomiques (entre les espèces) et pour la corrélation des composés contenus avec une activité pharmacologique. / Medicinal plants constitute an unfailing source of compounds (natural products – NPs) utilised in medicine for the prevention and treatment of various deceases. The introduction of new technologies and methods in the field of natural products chemistry enabled the development of high throughput methodologies for the chemical composition determination of plant extracts, evaluation of their properties and the exploration of their potentials as drug candidates. Lately, metabolomics, an integrated approach incorporating the advantages of modern analytical technologies and the power of bioinformatics has been proven an efficient tool in systems biology. In particular, the application of metabolomics for the discovery of new bioactive compounds constitutes an emerging field in natural products chemistry. In this context, Acronychia genus of Rutaceae family was selected based on its well-known traditional use as antimicrobial, antipyretic, antispasmodic and anti-inflammatory therapeutic agent. Modern chromatographic, spectrometric and spectroscopic methods were utilised for the exploration of their metabolite content following three basic axes constituting the three chapters of this thesis. Briefly, the first chapter describes the phytochemical investigation of Acronychia pedunculata, the identification of secondary metabolites contained in this species and evaluation of their biological properties. The second chapter refers to the development of analytical methods for the identification of acetophenones (chemotaxonomic markers of the genus) and to the dereplication strategies for the chemical characterisation of extracts by UHPLC-HRMSn. The third chapter focuses on the application of metabolomic methodologies (LC-MS & NMR) for comparative analysis (between different species, origins, organs), chemotaxonomic studies (between species) and compound-activity correlations.
89

Detecció dels metabòlits del plastificant di(2-etilhexi)l ftalat com a marcadors de l'ús de transfusions en l'esport

Monfort Mercader, Núria, 1983- 19 December 2012 (has links)
El di(2-etilhexil) ftalat (DEHP) és un plastificant que s’afegeix als productes de clorur de polivinil (PVC) per a dotar-los de més flexibilitat. El material mèdic fet de PVC, i en particular els dispositius i bosses que s’utilitzen en les transfusions de sang, conté el DEHP com additiu. Així, el receptor d’una transfusió està altament exposat a aquest compost. L’objectiu de la tesi va ser estudiar els metabòlits del DEHP en orina com a possibles marcadors de la pràctica d’una transfusió de sang en l’esport. Es va desenvolupar i validar un mètode d’anàlisi per cromatografia líquida acoblada a espectrometria de masses en tàndem per a la quantificació dels principals metabòlits del DEHP en orina humana: mono-(2-etilhexil) ftalat (MEHP), mono-(2-etil-5-hidroxihexil) ftalat (MEHHP), mono-(2-etil-5-oxohexil) ftalat (MEOHP), mono-(2-carboximetilhexil) ftalat (2cx-MMHP) i mono-(2-etil-5-carboxipentil) ftalat (5cx-MEPP). El mètode es va aplicar a mostres procedents de voluntaris sans (grup control), de pacients hospitalitzats que havien rebut una transfusió de sang i de pacients hospitalitzats sotmesos a tractaments mèdics amb materials de PVC i no a transfusions. Es van obtenir diferències significatives en les concentracions dels tres metabòlits estudiats (MEHP, MEHHP, MEOHP) entre les mostres dels pacients transfosos respecte els altres dos grups de població. El mètode també es va aplicar a mostres d’orina de vint-i-cinc voluntaris sans que s’havien sotmès a un procediment d’autotransfusió. Els resultats van indicar concentracions elevades dels cinc metabòlits del DEHP en orina fins a les 48 hores després d’haver rebut la sang. Finalment, es van determinar les concentracions dels cinc metabòlits de DEHP en una població d’esportistes i es van calcular límits de referència que permetessin sospitar d’una transfusió. Així doncs, els resultats indiquen que la mesura dels metabòlits de DEHP en orina pot ser usada com una eina pel cribatge de l’ús de transfusions en l’esport. / The plasticizer di(2-ethylhexyl)phthalate (DEHP) is used in polyvinyl chloride products (PVC) to increase its flexibility. Medical devices made of PVC, especially blood bags used in blood transfusions, contain DEHP as additive. Therefore, subjects submitted to blood transfusion are widely exposed to this compound. The aim of the project was to evaluate DEHP metabolites in urine as possible markers of the use of a blood transfusion in sports. An analytical method was developed and validated to quantify the main DEHP metabolites mono-(2-ethylhexyl)phthalate (MEHP), mono-(2-ethyl-5-hydroxyhexyl)phthalate (MEHHP), mono-(2-ethyl-5-oxohexyl)phthalate (MEOHP), mono-(2-carboxymethylhexyl)phthalate (2cx-MMHP) and mono-(2-ethyl-5-carboxypentyl)phthalate (5cx-MEPP), in human urine by liquid chromatography tandem mass spectrometry. The methodology was applied to samples belonging to healthy volunteers (control group), hospitalized patients subjected to blood transfusions and hospitalized patients subjected to medical treatments involving plastic material different to blood transfusions. Significant differences were obtained in the concentrations of the three metabolites studied (MEHP, MEHHP, MEOHP) between transfused patients samples’ and the other two population groups. The method was also applied to urine samples from twenty-five healthy volunteers who were subjected to an autologous blood transfusion. The results indicated high concentrations of the five DEHP metabolites in urine up to 48 hours after the blood transfusion. Finally, the concentration of the five DEHP metabolites were evaluated in a sportsmen population and reference limits to allow suspicion of blood transfusion were calculated. Thus, the results indicate that the DEHP metabolites could be used as markers of blood transfusions in sports.
90

Ethnobotany, Pharmacology, and Metabolomics of Antidiabetic Plants used by the Eeyou Istchee Cree, Lukomir Highlanders, and Q’eqchi’ Maya

Ferrier, Jonathan 15 January 2014 (has links)
A study was undertaken of plants used for treatment of diabetic symptoms by traditional healers of the Eeyou Istchee Cree (Canada), Lukomir Highlanders (Bosnia & Herzegovina), and Q’eqchi’ Maya (Belize). All antidiabetic plants were ranked by syndromic importance value (SIV) based on 15 symptoms, all of which were recognized by the Cree and Maya and 8 by the Highlanders. The Cree used only 18 species, the Highlanders 41, and the Maya 150, numbers which reflect the diversity of flora in their region. Vaccinium (Ericaceae) was one of the few genera in all three regions and the only consensus genus between the Cree and Highlander study sites. The Q’eqchi’ Maya ethnobotany did not present any cross-cultural consensus genera with Cree or Highlander medicinal plants, perhaps due to major biogeographic differences. In ethnopharmacological studies, Vaccinium species and Q’eqchi’ antidiabetic plants were tested in an assay relevant to diabetes, the advanced glycation endproduct (AGE) inhibition assay. Boreal and tropical Vaccinium species were potent inhibitors of AGEs and demonstrated concentration dependent inhibition, with a half maximal inhibitory concentration (IC50) range of 5.93–100 µg/mL. Phenolic content ranged from 80.3 to 201 µg/mL in boreal samples and from 1470 to 2170 µg/mL in tropical samples. Tropical species have a greater phenolic content and AGE inhibition. Seven Q’eqchi’ antidiabetic plant species were tested and all plant extracts showed AGE-inhibition. The IC50s ranged from 40.8 to 733 µg/mL, and the most active was Tynanthus guatemalensis Donn.. Tynanthus guatemalensis IC50 was about fives times greater (less active) than the mean ± SE IC50 reported for six tropical Vaccinium species of Vaccinium (8.77 ± 0.79 μg/mL). The highest consensus and most active Maya antidiabetic plant, Tynanthus guatemalensis Donn. Sm. was discovered to be an important plant recorded in archeological artifacts from the Late Classic Maya period (~750 CE). Ancient Maya used a cross shaped sign (k’an glyph) as a decorative element on Late Classic polychrome vessels and murals. The sign was believed to be the xylem template for a plant used as a flavouring in cacao drinks. However, the plant was incorrectly identified in the literature as Pimenta dioica (L.) Merr. (common name: Allspice) based on a common name and aromatic plant quality – not from a botanical voucher specimen. Pimenta dioica wood does not have a cross shape visible in the xylem but a unique character visible after a cross section of T. guatemalensis, is the xylem's cross shape organization. Wood of T. guatemalensis' also has an "allspice" aroma. Tynanthus guatemalensis is most likely the true botanical template behind the ancient Maya k’an glyph and this finding would show the continuity of use of this medicinal plant from ancient to modern times. Vaccinium was selected for an in depth phytochemical analysis using modern metabolomic methods. Nuclear magnetic resonance (1H NMR) was used to evaluate leaf extract spectra to provide information on (1) the taxonomic identity and (2) quantities of bioactive metabolites across multiple sites. Spectra clearly differentiated leaf samples of V. angustifolium, V. boreale, V. corymbosum, V. macrocarpon, V. myrtilloides, V. myrtillus, V. ovalifolium, and V. uliginosum according to generic, subgeneric, specific, phenotypic circumscriptions. Quantification of chlorogenic acid and hyperoside were replicated with a method that is highly reproducible across multiple sites with different NMR equipment. This methodology provides an important new approach to taxonomy and quality control for plants and natural health products.

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