Tesis sobre el tema "Metabolomics, Nuclear Magnetic Resonance"

Hypoxia has emerged as a crucial part of the aetiology of tumours. It is a negative prognostic factor which is associated to chemoresistance, invasiveness and metastasis. There is a strong association between hypoxia and metabolic transformation in breast cancer due to the alterations of multiple metabolic pathways. However, the current understanding of the nature of metabolic alterations in hypoxia is insufficient. This thesis uses NMR as a tool to investigate both the static metabolome by measuring metabolite concentrations, as well as to determine \(^1\)\(^3\)C metabolic fluxes using stable isotope tracers to reveal metabolic pathway alterations by hypoxia in vitro and by tumour growth in vivo. Firstly, we developed the \(^1\)\(^3\)C isotopomer distribution (CID) analysis to quantify metabolic fluxes by following the evolution of specific isotopomers of specific pathways of interests. MCF7 breast cancer cells were analysed in hypoxia using an integrated approach using gene expression, steady-state metabolite levels and \(^1\)\(^3\)C metabolic flux analysis to pinpoint hypoxia induced metabolic alterations. These most significant alterations were an up-regulation of the pentose phosphate pathway and a down-regulation of mitochondrial oxidative metabolism by lowering the PDH flux. The latter was partially compensated by carbon entry into the mitochondria by increasing flux through pyruvate carboxylase (PC). Further attention was focused towards identifying the shifts in metabolic activity in PC altered cells using [1,2-\(^1\)\(^3\)C]glucose and [3-\(^1\)\(^3\)C]glutamine as precursor nutrients correlated to cellular transformation potential accessed by cell viability. Finally, the \(^1\)\(^3\)C labelled glucose strategy was applied to a cancer model in mice model by infusing mice with [1,2-\(^1\)\(^3\)C]glucose. \(^1\)\(^3\)C glucose administration protocol was optimised in order to enable an investigation of \(^1\)\(^3\)C metabolic fluxes in tumour tissue to identify metabolic pathway differences between earlier stage and advanced stage of mammary gland tumours. In conclusion, an NMR based metabolomics analysis is suitable for discovering metabolic pathway alterations using both in vitro and in vivo models.

La résonance magnétique nucléaire (RMN) est devenue une des techniques spectroscopiques les plus puissantes et polyvalentes de la chimie analytique avec des applications multiples dans des différents domaines de la recherche. Cependant, un des inconvénients majeurs de la RMN est le processus fastidieux d'analyse de donnée qui nécessite fréquemment des interventions humaines. Ces dernières font diminuer non seulement l'efficacité et l'objectivité des études mais également renferment les champs d'applications potentielles de la RMN pour les non-initiés. Par conséquent, le développement des méthodes computationnelles non supervisées se trouve nécessaire. Les travaux réalisés ici représentent des nouvelles approches dans le domaine de la métabolomique et de la biologie structurelle. Le défi ultime de la RMN métabolomique est l'identification complète de l'ensemble des molécules constituant les échantillons biologiques complexes. Cette étape est vitale pour toute interprétation biologique. Dans la première partie de cette thèse, une nouvelle méthode numérique a été développée pour analyser des spectres à deux dimensions HSQC et TOCSY afin d'identifier les métabolites. La performance de cette nouvelle méthode a été démontrée avec succès sur les données synthétiques et expérimentales. La RMN est une des principales techniques analytiques de la biologie structurale. Le processus conventionnel de détermination structurelle est bien établie avec souvent une attribution explicite des signaux. Dans la seconde partie de cette thèse, une nouvelle approche computationnelle est présentée. Cette nouvelle méthode permet de déterminer les structures RMN sans attributions explicites des signaux. Ces derniers proviennent de données spectrales tridimensionnelles TOCSY et NOESY. Les structures ont été résolues en appliquant cette nouvelle méthode aux données spectrales d'une protéine de 12kDa
Nuclear Magnetic Resonance (NMR) has become one of the most powerful and versatile spectroscopic techniques in analytical chemistry with applications in many disciplines of scientific research. A downside of NMR is however the laborious data analysis workflow that involves many manual interventions. Interactive data analysis impedes not only on efficiency and objectivity, but also keeps many NMR application fields closed for non-experts. Thus, there is a high demand for the development of unsupervised computational methods. This thesis introduces such unattended approaches in the fields of metabonomics and structural biology. A foremost challenge to NMR metabolomics is the identification of all molecules present in complex metabolite mixtures that is vital for the subsequent biological interpretation. In this first part of the thesis, a novel numerical method is proposed for the analysis of two-dimensional HSQC and TOCSY spectra that yields automated metabolite identification. Proof-of principle was successfully obtained by evaluating performance characteristics on synthetic data, and on real-world applications of human urine samples, exhibiting high data complexity. NMR is one of the leading experimental techniques in structural biology. However the conventional process of structure elucidation is quite elaborated. In this second part of the thesis, a novel computational approach is presented to solve the problem of NMR structure determination without explicit resonance assignment based on three-dimensional TOCSY and NOESY spectra. Proof-of principle was successfully obtained by applying the method to an experimental data set of a 12-kilodalton medium- sized protein

Objectives: Three objectives of this thesis have been: (i) Mastering of the main analytical platforms used in metabolomics, (ii) Developing an untargeted metabolomic workflow, involving novel aspects of sample preparation, and data processing for metabolite identification, (iii) Implementing our untargeted metabolomic workflow to the study of human patients with Polycystic Ovary Syndrome (PCOS) and their response to drug treatment Results: In Work 1: Optimization metabolite extraction conditions for NMR analysis, followed by LC/ESI-MS by using the same sample extract with no need for solvent exchange or further pretreatment. In Work 2: Investigate the impact of different aspects of univariate statistical analysis on untargeted LC-MS based metabolomic experiments. In Work 3: Implementation of GC-MS untargeted metabolomic approach to provide new insights on the impact that obesity exerts on the metabolic derangements associated with PCOS. In Work 4: Implementation of multiplatform metabolomics approach based on NMR and LC-MS to provide new insights in PCOS disease in a cohort of young lean PCOS patients. In Work 5: Implementation of multiplatform metabolomics approach based on NMR, GC-MS and LC-MS to provide new insights on the action of drug polytherapy to PCOS disorder. Conclusion: Metabolomics can be consider as a powerful tool for the study of metabolic disorders. Furthermore, metabolite profiling has demonstrated feasibility and flexibility for revealing new mechanistic insights in metabolic disorders that are not been consider when classical analysis is used. Therefore, our metabolomic analysis have demonstrated a great potential as a useful diagnostic technique and can facilitate monitoring of both disease progression and effects of therapeutic treatment.
Objetivos: El presente trabajo tiene dos objetivos generalizables que han sido estudiados con más detalle en la presente tesis doctoral. El primero de ellos es mejorar aspectos metodológicos en el ámbito de la metabolómica y el segundo ha sido la aplicación de la metabolómica en el estudio del síndrome del ovario poliquístico (PCOS). Resultados: Del primer objetivo se han realizado dos trabajos: en el primero, la optimización de un método de extracción común para analizar muestras biológicas en dos plataformas analíticas complementarias utilizadas en metabolómica como son la resonancia magnética nuclear y la espectrometría de masas. Del segundo trabajo realizado se han obtenido unas pautas para abordar los retos que surgen del análisis de datos de metabolómica en espectrometría de masas. Del segundo objetivo también han sido realizados dos trabajos: en ambos se ha utilizado la metabolómica no dirigida para abordar el estudio del PCOS. En el primer trabajo, se ha utilizado la metabolómica para conocer el impacto que ejerce la obesidad en los trastornos metabólicos asociados al PCOS. En el segundo trabajo, se ha utilizado la metabolómica no dirigida para evaluar como afecta la aplicación de una politerapia con medicamentos al metabolismo de pacientes con PCOS. Conclusión: La metabolómica puede ser utilizada como una nueva herramienta para estudiar los trastornos metabólicos.

The researcher studied the role of amino acid metabolism in osteoarthritis progression. The study suggests that this abnormal amino acid metabolism aids in the development of the disease. This data further suggests that amino acids could be potential circulatory markers for diagnosing OA and therapeutic strategies of amino acids supplementation could be considered as a potential treatment.

A pesquisa bioquímica no campo da Metabolômica/Metabonômica tem se intensificado consideravelmente nos últimos anos, por sua capacidade de adquirir uma grande quantidade de informação a respeito do comportamento de um organismo através de seu metabolismo. Para isso, frequentemente faz uso da aplicação das mais diversas técnicas analíticas, como a Ressonância Magnética Nuclear. A Ivermectina é um fármaco de amplo uso no Brasil, dada a sua eficiência no controle de verminoses e pragas em gado (e humanos) e está aqui inserida no contexto metabolômico/metabonômico dadas as inúmeras violações ocorridas na carne brasileira exportada. A não observância dos períodos adequados de carência para abate dos animais tratados pode refletir seriamente na qualidade destes produtos. Assim, utilizou-se a Ivermectina como forma de provocar mudanças no metabolismo de bovinos e camundongos, procurando-se correlacionar as variações encontradas à dose aplicada. Através de ferramentas auxiliares, como RMN-2D e ferramentas quimiométricas exploratórias, fez-se a avaliação de amostras de plasma sanguíneo e urina bovinos, e plasma sanguíneo de camundongos Balb-C, após administração de Ivermectina. Os resultados obtidos mostram que a Ivermectina tem influência no balanço energético do organismo, interferindo nos níveis de lactato e β-hidróxibutirato, podendo estar ligada ao aparecimento de uma condição metabólica crítica em mamíferos, relacionada à alta concentração de corpos cetônicos na corrente sanguínea dos mesmos.
The biochemical research in the field of Metabolomics/ Metabonomics has grown considerably in recent years because its capability of acquiring a large amount of information about the behavior of an organism through its metabolism. For this, it often applies several analytical techniques such as Nuclear Magnetic Resonance. Ivermectin is a drug widely used in Brazil, for its effectiveness in controlling verminosis and pests in livestock (and humans) and is here inserted in the metabolomic/metabonomic context because of the numerous breaches occurred in brazilian beef exports. Failures to comply with the appropriate withdrawal periods for slaughtering treated animals may reflect seriously on the quality of these products. Thus, we used Ivermectin as a metabolism change inducer in cattle and mice, trying to correlate these variations to the applied dose. Through auxiliary tools such as 2D-NMR and chemometric exploratory tools, we evaluated samples of bovine blood plasma and urine, and blood plasma of Balb-C mice, after Ivermectin administration. The results show that Ivermectin has influence on the organism\'s energy balance, interfering with lactate and β-hydroxybutyrate which can be connected to the onset of a critical metabolic condition in mammals, related to the high concentration of ketone bodies in their blood stream.

Pseudomonas aeruginosa is a metabolically versatile environmental bacterium that grows in extremely diverse habitats—from sea water to jet fuel—and is able to infect a large variety of organisms. It is a significant cause of human disease and is one of the most frequent healthcare-associated infections. P. aeruginosa uses a sophisticated gene regulatory network to adapt its growth strategy to these diverse environmental niches and the fluctuating conditions it encounters therein. The las and rhl “quorum sensing” (QS) intercellular communication systems play integral roles in this regulatory network and control the expression of factors important to the bacterium’s ecological fitness, including many secreted factors involved in nutrient acquisition, microbial competition, and virulence. These QS systems use diffusible acyl-homoserine lactone (AHL) signalling molecules to infer environmental parameters, including bacterial population density, and to coordinate behaviour across bacterial communities. This dissertation describes an investigation into the relationship between QS and small molecule primary metabolism, using metabolomic methods based on nuclear magnetic resonance spectroscopy and mass spectrometry. Analysis of extracellular metabolic profiles (the bacteria’s “metabolic footprint”) established that QS can modulate the uptake and excretion of primary metabolites and that this effect was strongest during the transition from exponential to stationary phase cell growth. Analysis of the cellular metabolome and proteome demonstrated that QS affected most major branches of primary metabolism, notably central carbon metabolism, amino acid metabolism and fatty acid metabolism. These data indicate that QS repressed acetogenesis and the oxidative C02-evolving portion of the TCA cycle, while inducing the glyoxylate bypass and arginine fermentation. QS also induced changes to fatty acid pools associated with lower membrane fluidity and higher chemical stability. Elevated levels of stress-associated polyamines were detected in QS mutants, which may be a consequence of a lack of QS-dependent adaptations. These findings suggest that wild-type QS directs metabolic adaptations to stationary phase stressors, including oxidative stress. Previous work, including several transcriptomic studies, has suggested that QS can play a role in primary metabolism. However, there has been no previous study of the global impact of AHL QS on the metabolome of P. aeruginosa. Research presented here demonstrates that QS induces a global readjustment in the primary metabolism and provides insight into QS- dependent metabolic changes during stationary-phase adaptation.

Mestrado em Bioquímica - Bioquímica Clínica
The use of metabolomics to reveal response markers of efficacy or toxicity, as well as to provide biochemical insight into mechanisms of action has gained increasing interest in the research community. In this work, the effects of silk nanoparticles on the metabolism of macrophages, which are an important cell type in regard to NP uptake, was addressed through Nuclear Magnetic Resonance (NMR) spectroscopy metabolomics. Firstly, 1D and 2D NMR spectroscopy was applied to determine the metabolic composition of murine macrophages (RAW 264.7 cell line), through the analysis of both aqueous and lipid extracts. Almost forty metabolites were identified, establishing a database of metabolites of murine macrophages. Afterwards, murine macrophages were exposed to two concentrations of silk nanoparticles (10 and 500 μg/mL), selected based on cytotoxicity data collected previously to this work, and the impact on their metabolic composition was assessed. Multivariate analysis was applied to the 1D 1H NMR spectra in order to search the compositional changes in macrophages during silk nanoparticles’ (SNPs) exposure. It was found that the low concentration SNPs induced few changes in the cells metabolome compared to the high concentration SNPs, which resulted in biochemical changes related to energy metabolism and TCA cycle, disturbance of amino acids metabolism and cell membrane modification. Some variations were common to all exposure periods, such as the increase in branched chain amino acids, lactate and tyrosine and the decrease in glutamine, taurine, myo-inositol and ATP/ADP, whereas other variations seemed to be more time-specific. The time-dependent fluctuations were also visible in lipids, where cholesterol, cholesterol esters and sphingomyelin were found to be relatively higher in SNP-exposed samples, while unsaturated fatty acids, plasmalogen and phosphatidylcholine were higher in controls. These results have shown that the use of NMR metabolomics to evaluate a nanomedicine performance may be a powerful tool to improve our understanding of cell-nanomaterial interactions and of the mechanisms underlying observed toxicities.
A aplicação da metabolómica com o intuito de revelar biomarcadores de eficácia ou toxicidade, assim como de fornecer uma compreensão bioquímica de mecanismos de ação, tem ganho maior interesse na comunidade científica. Neste trabalho os efeitos das nanopartículas de seda no metabolismo de macrófagos, que são um tipo celular importante no que diz respeito à incorporação de nanopartículas, foram investigados por metabolómica de espectroscopia de Ressonância Magnética Nuclear (RMN). Inicialmente, espectroscopia de RMN 1D e 2D foi aplicada para determinar a composição metabólica de macrófagos de rato (linha celular RAW 264.7), através da análise de extratos aquosos e lipídicos. Cerca de quarenta metabolitos foram identificados, estabelecendo uma base de dados dos metabolitos de macrófagos de rato. De seguida, esses macrófagos foram expostos a duas concentrações de nanopartículas de seda (10 e 500 μg/mL), selecionadas com base nos dados citotoxicológicos recolhidos previamente a este trabalho, e o seu impacto no metabolismo foi averiguado usando a mesma metodologia. Análise multivariada foi aplicada aos espectros de 1H RMN 1D de forma a investigar as alterações na composição dos macrófagos durante a exposição às nanopartículas de seda (SNPs). A concentração baixa de SNPs induziu poucas alterações no metaboloma celular comparativamente à concentração alta de SNPs, que resultou em alterações bioquímicas no metabolismo energético e ciclo do ácido cítrico, distúrbios no metabolismo de aminoácidos e modificações na membrana celular. Algumas variações foram comuns a todos os períodos de exposição, tais como o aumento dos aminoácidos de cadeia ramificada, lactato e tirosina, e a diminuição de glutamina, taurina, myo-inositol e ATP/ADP, enquanto que outras se revelaram ser mais específicas em relação ao tempo de exposição. As flutuações dependentes do tempo foram também visíveis nos lípidos, onde o colesterol, ésteres de colesterol e esfingomielina se encontraram mais elevados nas amostras expostas à concentração elevada de SNPs, enquanto que os ácidos gordos insaturados, plasmalogénio e fosfatidilcolina estavam mais elevados nos controlos. Estes resultados demonstraram que a aplicação de metabolómica de RMN para avaliar o desempenho de nanofármacos pode ser uma ferramenta importante para melhorar a nossa compreensão das interações célula-nanomaterial e os mecanismos subjacentes à toxicidade observada.

La métabolomique a acquis au cours des dernières années une place privilégiée en oncologie et en recherche sur la biologie du cancer. La métabolomique cellulaire offre un grand potentiel pour élargir notre champs de connaissance sur les mécanismes du développement tumoral et sur les aspects fondamentaux de la biologie du cancer. Nous avons utilisé l’approche métabolomique par résonance magnétique nucléaire (RMN) pour caractériser les profils métaboliques de lignées cellulaires de cancer suite à leur exposition à des facteurs influençant leur réponse aux traitements. Premièrement, nous avons développé une méthodologie rigoureuse, rapide et ergonomique d’extraction des métabolites pour l’analyse métabolomique à partir de cultures cellulaires adhérentes mammifères. Par la suite, l’approche métabolomique a été utilisée pour étudier l’effet des adipocytes, constituants du microenvironnement tumoral, sur les exo- et endo-métabolomes des cellules cancéreuses HER2-positif. Il a été auparavant démontré que les adipocytes agissent sur les cellules cancéreuses HER2-positif en co-culture par l’intermédiaire de leurs facteurs sécrétés en induisant une résistance aux thérapies ciblées. L’ajout d’un stimulateur de lipolyse (isoprénaline, agoniste des récepteurs adrénergiques) au système de co-culture induit une résistance aux thérapies ciblées au moins aussi importante qu’en présence d’adipocytes seuls. Au contraire, l’ajout du propranolol (β-bloquant non sélectif) permet de retrouver la sensibilité de cellules cancéreuses aux thérapies ciblées. L’analyse métabolomique permet d’élucider les aspects mécanistiques mises en jeu lors de cette interaction en étudiant ses conséquences sur les profils métaboliques des cellules cancéreuses. L’analyse quantitative des métabolites présents dans les surnageants de culture montre une forte altération du métabolisme des cellules cancéreuses HER2-positif incubées en milieu conditionné d’adipocytes. Les cellules cancéreuses ne dépendent plus de la glycolyse aérobie mais privilégient l’utilisation d’autres carburants tels que le lactate et le glycérol. L’étude pharmaco-métabolomique des adipocytes et des cellules cancéreuses HER2-positif en présence de modulateurs de lipolyse confirme ces résultats et permet d’observer les changements métaboliques au niveau intracellulaire. Un dernier axe de ce travail porte sur l’étude des profils métaboliques des cellules du cancer de côlon suite à la déplétion de la machinerie AIF/CHCHD4. Les déficits du métabolisme mitochondrial oxydatif sont associées à de nombreuses maladies. Bien qu’une discrimination robuste n’ait pu être observée entre les groupes contrôle et déplété CHCHD4, nous avons identifié un nombre de variables confondantes dont le contrôle est nécessaire pour des études avancées sur le métabolisme oxydatif des cellules cancéreuses avec déplétion de CHCHD4
Metabolomics has become an established tool for oncology and cancer biology research studies. Cell metabolomics is a rapidly growing field that addresses fundamental aspects of cancer biology and provides mechanistic insights into disease development, progression and response to therapies. We developed and applied cell metabolomics approaches by liquid nuclear magnetic resonance (NMR) at very high fields to study the effect of different factors on cancer cells metabolic profiles and ultimately their response to therapy. First we developed a fast, rigorous and ergonomic extraction protocol of adherent mammalian cells for NMR-based metabolomics studies. Then we investigated the effect of adipocytes on HER2-positive cancer cells exo- and endometabolomes. Adipocytes were previously shown to act on HER2-positive cells to decrease their sensitivity to targeted therapy in co-culture. Addition of a lipolysis stimulator (isoprenaline, a β-adrenoreceptor agonist) to the system led to resistance of HER2-positive cells to targeted therapy at least as strong as in the case of adipocytes alone. Conversely, addition of a lipolysis inhibitor (non-selective β-blocker propranolol) rescued the response to therapy. Investigation of supernatants of HER2-positive cells cultures exposed to conditioned media from adipocytes showed strong metabolic alterations in cancer cells exometabolomes. Quantitative analysis of HER2-positive cell footprints shows that tumor cells switched their metabolism from aerobic glycolysis to scavenging various metabolites such as lactate and glycerol. A pharmaco-metabolomic investigation of adipocytes and HER2-positive cancer cells co-cultures and associated controls, conducted with or without addition of propranolol and isoprenaline, confirmed the observed metabolic shift. It revealed changes occurring in adipocytes and HER2-positive cancer cells following exposition to lipolysis modulators. Overall, this metabolomics investigation provides new insights into the mechanisms by which pharmacological modulation of lipolysis via β-adrenoreceptors impact on HER2-positive cancer cell metabolism. Finally, we studied the effect of the knockdown of AIF/CHCHD4 import machinery on colon cancer cells. Defects in oxidative energy metabolism is linked to several mitochondrial diseases that remain poorly understood. While no robust discrimination between control and CHCHD4 knockdown groups was observed, we identified a number of confounding factors that may be controlled for further investigation of oxidative energy metabolism in CHCHD4 knocked down cells

Doutoramento em Bioquímica
The work presented in this thesis aimed to investigate the impact of healthy pregnancy and selected prenatal disorders on the metabolome and lipidome of maternal blood plasma, in order to define new potential biomarkers for non-invasive prediction and diagnosis. Chapter 1 describes the present status and challenges of the clinically relevant prenatal disorders, along with a presentation of the metabolomics strategy applied and the state of the art of metabolomics in prenatal research. All experimental details are described in Chapter 2, comprising sample metadata, sample collection and preparation, data acquisition protocols and data analysis procedures. The plasma metabolome and lipidome viewed by 1D and 2D NMR experiments are presented in Chapter 3. In this chapter, the use of Multiple Quantum NMR spectroscopy was explored, for the first time, for assignment of complex lipid mixtures. Chapter 4 contributes to filling in some existing gaps regarding human plasma degradability during handling and storage, as well as the importance of fasting conditions at collection. The use of heparin collection tubes resulted in no interference of the polysaccharide and full conservation of spectral information, while EDTA tubes produced a number of interfering signals from free and Ca2+/Mg2+ complexed EDTA, the impact of which on metabolomic analysis is discussed. Regarding temperature stability, large changes in lipoproteins and choline compounds were observed in plasma kept at room temperature for  2.5 hours, whereas short-term storage at -20ºC was found suitable up to 7 days, with storage at -80ºC being recommended, particularly for long-term periods (at least up to 2.5 years). Regarding freeze-thaw cycles, no more than 3 consecutive cycles were found advisable, while the use of non-fasting conditions (instead of fasting) was found acceptable. Chapter 5 presents the first NMR metabolomics study of maternal plasma throughout pregnancy, including correlation between plasma and urine metabolites. Some of the metabolic alterations observed confirmed known metabolic effects, while novel changes were observed, suggesting adjustments in energy and gut microflora metabolisms (citrate, lactate and dimethyl sulfone) and alterations in glomerular filtration rate (creatine and creatinine). Correlations studies unveiled specific lipoprotein/protein metabolic aspects of healthy pregnancy with impact on the excreted metabolome, providing further understanding of pregnancy metabolism. In Chapter 6, the impact of prenatal disorders on maternal plasma metabolome and lipidome is described for fetal chromosomal disorders (CD), including Trisomy 21 (T21). High classification rates were obtained for CD (88-89%) and T21 (85-92%) in 1st and 2nd trimesters, based on variable selection of NMR data. In addition, novel metabolic deviations were found through plasma/urine correlations, namely in low density and very low density lipoproteins (LDL+VLDL), sugar and gut microflora metabolisms. Changes in plasma phospholipid profile, namely in phosphatidylcholines, were further confirmed and characterised by hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-LC/MS). In Chapter 7, metabolic biomarkers of pre- and post-diagnosis GDM were sought by NMR metabolomics of whole maternal plasma and plasma lipid profile in the 2nd trimester. Metabolic alterations found to be predictive of GDM comprised increases in cholesterol, fatty acids, triglycerides and small metabolites changes in glucose, amino acids, betaine, urea, creatine and metabolites related with gut microflora. Post-diagnosis GDM was successfully classified using a 26-resonance plasma biomarker corresponding to 10 metabolites and lipids, advancing the possibility of using a multi-metabolite biomarker as a complementary tool in the clinical management of GDM. Chapter 8 describes the results obtained for prenatal disorders shown to have lower impact on maternal plasma metabolome, namely diagnosed fetal malformations and pre-diagnosis premature rupture of membranes, preterm delivery and preeclampsia. Finally, Chapter 9 describes the general conclusions and future perspectives in the context of this thesis, highlighting how this work contributes with new knowledge on prenatal disease mechanisms and possible biomarkers for prenatal diagnosis and prediction methods.
O trabalho apresentado nesta tese teve como principal objetivo investigar o impacto da gravidez saudável e algumas doenças pré-natais no metaboloma e lipidoma de plasma sanguíneo materno, com vista à definição de novos biomarcadores para a previsão e diagnóstico não invasivos daquelas doenças. O Capítulo 1 descreve a perspectiva atual e os desafios das doenças pré-natais mais relevantes, assim como a estratégia metabolómica e estado da arte na investigação pré-natal. Todos os detalhes experimentais do trabalho realizado estão descritos no Capítulo 2, incluindo as condições de amostragem, recolha e preparação das amostras, bem como os protocolos de aquisição e análise dos dados. No Capítulo 3 descreve-se o metaboloma e lipidoma de plasma detectados por RMN 1D e 2D. Neste capítulo, a utilização de espectroscopia de RMN de quantum-múltiplo foi explorada, pela primeira vez, para caracterização de misturas lipídicas complexas. O Capítulo 4 contribui para colmatar algumas falhas no conhecimento sobre a degradibilidade do plasma humano durante o manuseamento da amostra e armazenamento, e a importância de condições de colheita como o jejum. A utilização de tubos de colheita com heparina não mostrou interferência do polissacarídeo nos espectros conservando-se toda a informação espectral, enquanto que os tubos com EDTA deram origem a sinais interferentes provenientes do EDTA livre e complexado com Ca2+/Mg2+, cujo impacto na análise metabolómica é discutido. Relativamente à estabilidade do plasma à temperatura ambiente, foram observadas alterações nas lipoproteínas e compostos de colina a partir de 2.5 horas, enquanto que o armazenamento a -20ºC mostrou ser adequado até 7 dias, sendo o armazenamento a -80ºC aconselhado, particularmente para períodos de tempo longos (pelo menos até 2.5 anos). Relativamente aos ciclos de congelação-descongelação, não se aconselham mais de 3 ciclos consecutivos, enquanto que o efeito da colheita das amostras em não-jejum (em vez de jejum) foi considerado aceitável. O Capítulo 5 apresenta o primeiro estudo de metabolómica por RMN do plasma materno ao longo da gravidez, incluindo correlação entre plasma e urina. Algumas das alterações metabólicas observadas confirmaram efeitos metabólicos conhecidos, tendo outras sido observadas pela primeira vez sugerindo alterações no metabolismo energético, na microflora bacteriana (citrato, lactato e dimetil sulfona) e na taxa de filtração glomerular (creatina e creatinina). Os estudos de correlação revelaram aspetos metabólicos específicos das lipoproteínas/proteínas com impacto no metaboloma excretado. No Capítulo 6 descreve-se o impacto das doenças cromossómicas (CD), incluindo Trissomia 21 (T21) no metaboloma e lipidoma de plasma materno. Obtiveram-se elevadas taxas de classificação para CD (88-89%) e T21 (85-92%) no 1º e 2º trimestres baseadas na seleção de variáveis dos dados de RMN. A correlação de plasma e urina revelou novos desvios metabólicos, nomeadamente no metabolismo das lipoproteínas de baixa densidade e de muito baixa densidade (LDL+VLDL), dos açúcares e da microflora bacteriana. As alterações observadas no perfil de fosfolípidos do plasma, nomeadamente das fosfatidilcolinas, foram confirmadas e caracterizadas por cromatografia liquida hidrofílica acoplada a espetrometria de massa (HILIC-LC/MS). No Capítulo 7 apresentam-se os resultados obtidos na prospecção de biomarcadores metabólicos de diabetes mellitus gestacional (GDM) pré- e pós-diagnóstico por metabolómica de RMN de plasma materno do 2º trimestre. Observaram-se alterações metabólicas com poder de previsão de GDM, nomeadamente um aumento no colesterol, ácidos gordos, triglicerídeos e pequenas variações metabólicas na glucose, aminoácidos, betaína, ureia, creatina e metabolitos relacionados com a microflora bacteriana. O grupo de GDM pós-diagnóstico foi bem classificado utilizando como biomarcador um conjunto de 26 ressonâncias do espectro de plasma correspondendo a lípidos e 10 metabolitos de baixo peso molecular, sugerindo-se a possibilidade de usar este marcador conjunto na gestão clínica da GDM. O Capítulo 8 descreve os resultados obtidos para as doenças pré-natais que mostraram ter um menor impacto no metaboloma de plasma materno, nomeadamente as malformações fetais (FM), e os estados de pré-diagnóstico da rutura prematura das membranas (PROM), parto pré-termo (PTD) e pré-eclampsia. Finalmente, no Capítulo 9 são descritas as conclusões gerais e perspetivas futuras no contexto desta tese, realçando-se como este trabalho contribui para o novo conhecimento dos mecanismos das doenças pré-natais e possíveis biomarcadores para a sua previsão e diagnóstico.

A RMN é uma das principais técnicas usadas no estudo de perfis metabólicos pois é uma técnica quantitativa, altamente reprodutível e não-seletiva. Desta forma, o objetivo desta tese foi a aplicação da RMN no estudo metabólico em diferentes processos biológicos. A primeira aplicação foi na análise do perfil metabolômico e metabonômico dos agentes causadores da leishmaniose. Para tal, foram analisados extratos celulares das espécies Leishmania major e Leishmania donovani e extratos destas espécies crescidas com os fármacos miltefosina e paromomicina. Os espectros de RMN de 1H foram analisados pelo programa ChenoMX e os espectros de RMN 2D pelo software TopSpin e as bases de dados HMDB e BMRB. Cerca de 50 metabólitos foram identificados, como a adenina, arginina, glutamina, glutamato, manose, isoleucina, leucina e tirosina. Técnicas quimiométricas como PCA, PLS-DA e heatmaps foram utilizadas para investigar os metabólitos responsáveis pela diferenciação das duas espécies bem como entre as culturas com e sem fármacos. O segundo estudo foi com o composto metilglioxal. A presença de metilglioxal em queijos contribui com o escurecimento e deterioração do sabor, mesmo em baixas temperaturas. Por esta razão, foram estudados os produtos da adição de metilglioxal em extrato de queijo parmesão e o comportamento de diferentes espécies de lactobacilos na presença e na ausência de metilglioxal em extrato de queijo parmesão. Os resultados permitiram um entendimento maior das reações envolvidas entre esta molécula e os componentes do queijo, o que ajudará encontrar alternativas para a resolução do problema e aumentar o tempo de prateleira do queijo. O terceiro estudo realizado foi sobre a produção de etanol a partir de biomassa lignocelulósica. O objetivo deste estudo foi modificar geneticamente uma espécie de lactobacilo para a produção de etanol e analisar a vinhaça de planta de etanol pós-fermentação com levedura. Os espectros de RMN de 1H e 1H-13C mostraram que as bactérias modificadas são eficientes na produção de etanol e que dois açucares foram erroneamente identificados por cromatografia como maltose e maltotriose quando na verdade eram trealose e arabinose.  Por meio destes destes estudos mostrou-se parte das inúmeras aplicações que a RMN tem na metabolômica e que existem diversas ferramentas estatísticas disponíveis para auxiliar no estudo metabolômico.
NMR is one of the main techniques used in metabolic profile studies because it is a quantitative, highly reproducible and non-selective technique. Thus, the aim of this thesis was the application of NMR in metabolic studies of different biological processes. The first application was the analysis of the metabolomic and metabonomic profile of the causative agents of leishmaniasis. Cell extracts of the species Leishmania major and Leishmania donovani and extracts of these species grown with miltefosine and paromomycin drugs were analyzed. 1H spectra were analyzed by ChenoMX software and 2D spectra by TopSpin software and HMDB and BMRB databases. About 50 metabolites were identified, such as adenine, arginine, glutamine, glutamate, mannose, isoleucine, leucine and tyrosine. Chemometric techniques were used to investigate the metabolites responsible for the differentiation of the two species and between cultures with and without drugs. The second study was with methylglyoxal molecule. The presence of methylglyoxal in cheese contributes to browning and deterioration of flavor, even at low temperatures. For this reason, products of the addition of methylglyoxal in Parmesan cheese extract and the behavior of different species of lactobacilli in the presence and absence of methylglyoxal in Parmesan cheese extract were studied. The results allowed a better understanding of the reactions involved between this molecule and the components of the cheese, which will help find alternatives to solve the problem and increase the shelf life of the cheese. The third study was about the production of ethanol from lignocellulosic biomass. The objective of this study was to genetically modify a lactobacillus species to produce ethanol and analyze the post-fermentation thin stillage. NMR spectra showed that the modified bacteria are efficient in production of ethanol and that two sugars were erroneously being identified by chromatography as maltose and maltotriose when they actually were trehalose and arabinose. These studies showed part of the numerous applications that NMR has in metabolomics and that there are several statistical tools available to assist in metabolomic studies.

Doutoramento em Nanociências e Nanotecnologia
Face ao uso disseminado e enorme potencial terapêutico das nanopartículas de prata (AgNPs), o estudo dos seus efeitos biológicos é um assunto relevante e atual. O trabalho apresentado nesta tese teve como objetivo aprofundar o conhecimento existente sobre o impacto das AgNPs no metabolismo celular, usando a metabolómica por espectroscopia de ressonância magnética nuclear (RMN). Os tipos celulares escolhidos para este estudo foram queratinócitos da epiderme humana, células de hepatoma humano e macrófagos sanguíneos, por serem relevantes, respetivamente, ao nível da entrada, acumulação e captação de nanopartículas no organismo. O Capítulo 1 introduz as principais propriedades das AgNPs, a sua atividade biológica e potencial toxicidade, e descreve a abordagem metabolómica, incluindo uma breve revisão bibliográfica das suas aplicações em nanotoxicologia. O âmbito e os objetivos desta tese são, também, apresentados. O Capítulo 2 descreve os métodos experimentais utilizados ao longo deste trabalho, incluindo a caracterização das AgNPs, os procedimentos usados na cultura celular e nos ensaios biológicos, a colheita e preparação de amostras, a análise por RMN e o tratamento estatístico dos dados. No Capítulo 3, a atividade metabólica e a composição dos três tipos de células usados neste trabalho (queratinócitos HaCaT, células de hepatoma HepG2 e macrófagos RAW 264.7) são descritas com base na análise por RMN dos sobrenadantes dos meios de cultura (exometaboloma) e dos extratos celulares polares e lipofílicos (endometaboloma). O Capítulo 4 apresenta a análise metabolómica das células HaCaT expostas a AgNPs de diferentes tamanhos (10, 30 ou 60 nm de diâmetro) e revestimentos (citrato, polietilenoglicol ou albumina de soro bovino). Verificou-se que o metaboloma celular foi afetado mesmo a concentrações subtóxicas de AgNPs, sugerindo: aumento da glicólise e glutaminólise, alteração na atividade do ciclo dos ácidos tricarboxílicos (TCA) e nos processos de produção e transferência de energia, degradação de proteínas, síntese de glutationa (GSH), modificações a nível das membranas e do equilíbrio osmótico. Apesar de muitas variações serem comuns a todas as nanopartículas testadas, as AgNPs de 10 nm causaram os efeitos mais distintos, nomeadamente no que diz respeito à glicólise e à síntese/utilização de GSH. Além disso, a exposição celular a prata iónica (Ag+) confirmou o importante papel dos iões prata no mecanismo de ação das AgNPs, enquanto a comparação com o peróxido de hidrogénio (H2O2) permitiu destacar os efeitos relacionados com o stress oxidativo. No Capítulo 5 são apresentadas as respostas metabólicas das células de fígado HepG2 a dois tipos de AgNPs, umas obtidas por redução química e estabilizadas em citrato e as outras obtidas por síntese verde na presença de um extrato vegetal (Cit30 e GS30, respetivamente), ambas com centros metálicos de 30 nm. Os resultados sugeriram adaptações metabólicas em processos de produção de energia (metabolismo da glucose e sistema da fosfocreatina), autofagia e metabolismo lipídico, refletindo possivelmente a ativação de mecanismos de proteção. Ainda que os dois tipos de AgNPs tenham induzido muitos efeitos semelhantes, as Cit30 pareceram causar um maior impacto no ciclo TCA e na degradação de proteínas, enquanto as GS30 aparentaram induzir uma diminuição mais forte na síntese de fosfolípidos. A assinatura metabólica da prata iónica foi bastante semelhante à das AgNPs, sugerindo, no entanto, uma menor capacidade das células expostas a Ag+ extracelular para lidar com o stress oxidativo. O Capítulo 6 descreve a avaliação do impacto das AgNPs Cit30 no metaboloma de macrófagos de murganho RAW 264.7, a concentrações subtóxicas (decréscimos de ~5 e 20% na viabilidade celular). As alterações encontradas apontaram para: estimulação da glicólise (a baixa concentração de exposição), reprogramação do ciclo TCA (resultando numa intensa produção de itaconato e succinato e numa marcada depleção de ATP, consistentes com uma resposta pro-inflamatória), ativação da gluconeogénese, promoção da síntese de GSH e acumulação de creatina/fosfocreatina. Foram, ainda, observadas variações possivelmente relacionadas com a osmorregulação e a modificação membranar. De notar que os macrófagos expostos a Ag+ mostraram características semelhantes aos expostos a AgNPs (por ex., aumento da glucose intracelular – gluconeogénese), mas também revelaram efeitos distintos, nomeadamente em metabolitos envolvidos no ciclo TCA, em processos de transferência de energia e no metabolismo lipídico. Adicionalmente, viu-se que o metaboloma dos macrófagos respondeu de maneira diferente à exposição a H2O2 (por ex., tendência para diminuição da glicólise e sem efeitos observados na ativação da gluconeogénese ou da síntese de GSH), indicando que muitos dos efeitos induzidos pelas AgNPs não foram necessariamente mediados por stress oxidativo. Finalmente, com base na integração dos resultados apresentados ao longo dos capítulos anteriores, as principais conclusões deste trabalho são apresentadas e discutidas no Capítulo 7.
The wide dissemination and promising therapeutic potential of silver nanoparticles (AgNPs) make the study of their biological effects a relevant upto- date subject. The work presented in this thesis aimed at deepening current understanding of the impact of AgNPs on cell metabolism, using NMR metabolomics of cultured mammalian cells. Epidermis keratinocytes, hepatoma cells and blood macrophages, relevant, respectively, to nanoparticle entry, accumulation and uptake, have been selected for the study. Chapter 1 introduces the main properties of AgNPs, including their biological activity and toxicological potential, and describes the metabolomics approach, briefly reviewing its applications in the field of nanotoxicology. Also, the scope and aims of this thesis are presented. Chapter 2 covers the experimental methods adopted during the course of this work, including the sources and characterisation of AgNPs, the procedures used in cell culture and biological assays, sample collection and preparation methods, NMR analyses and statistical data treatment. In Chapter 3, the metabolic activity and composition of the three cell types used in this work (HaCaT keratinocytes, HepG2 hepatoma cells and RAW 264.7 macrophages) are described based on the NMR analysis of culture medium supernatants (exometabolome) and polar/lipophilic cell extracts (endometabolome). Chapter 4 presents the metabolomic analysis of HaCaT skin cells exposed to AgNPs of different sizes (10, 30 or 60 nm in diameter) and coatings (citrate, polyethylene glycol or bovine serum albumin). The cellular metabolome was found to be affected even at sub-toxic concentrations of AgNPs, suggesting: upregulation of glycolysis and glutaminolysis, altered tricarboxylic acid (TCA) cycle activity, protein degradation, disruption of energy-producing pathways, glutathione (GSH) synthesis, membrane modification and changes in osmotic balance. Although several metabolic variations were common to all tested nanoparticles, the 10 nm AgNPs showed the most distinct effects, namely in regard to glycolysis and GSH synthesis/utilisation. Furthermore, cell exposure to ionic silver (Ag+) confirmed the major role of silver ions in AgNPs mode of action, while comparison with hydrogen peroxide (H2O2) allowed the effects related to oxidative stress to be highlighted. In Chapter 5, the metabolic responses of liver HepG2 cells to two types of 30 nm AgNPs, obtained by chemical reduction and stabilised with citrate or produced by green synthesis in the presence of a plant extract (Cit30 and GS30, respectively) are presented. Sub-toxic concentrations of AgNPs were proposed to induce metabolic adaptations in energy production processes (glucose metabolism and the phosphocreatine system), autophagy and lipid metabolism, possibly reflecting the activation of metabolism-mediated protective mechanisms. Although the two types of AgNPs induced many common effects, Cit30 appeared to have a greater impact on the TCA cycle and protein degradation, whereas GS30 seemed to induce stronger downregulation of phospholipid synthesis. The metabolic signature of Ag+ was largely similar to that of AgNPs, although suggesting a lower ability of cells exposed to extracellular Ag+ to cope with oxidative stress. Chapter 6 addresses the impact of Cit30 AgNPs on the metabolome of murine RAW 264.7 macrophages, at concentrations causing minimal (~5 and 20%) decreases in cell viability. Exposed cells were suggested to upregulate glycolysis (at the low exposure concentration), to reprogram the TCA cycle (resulting in marked production of itaconate and succinate and in ATP depletion, consistent with a pro-inflammatory response), to activate gluconeogenesis, to promote GSH synthesis, and to increase the creatine/phosphocreatine pool. Changes putatively related to osmoregulation and membrane modification were also observed. Notably, macrophages exposed to Ag+ showed common features to AgNPs-exposed cells (e.g. increased intracellular glucose suggesting gluconeogenesis), but also several distinct effects, for instance in metabolites involved in the TCA cycle, energy transfer processes or lipid metabolism. Furthermore, the cellular metabolome responded differently to H2O2 exposure (e.g. trend for downregulated glycolysis, no evidence of gluconeogenesis activation or of GSH upregulation), indicating that many of the AgNPs-induced effects were not necessarily mediated by oxidative stress. Finally, based on the integration of the results presented along the previous chapters, the main conclusions of this work are presented and discussed in Chapter 7.

Orientador: Mario Sergio Palma
Banca: Emanuel Carrilho
Banca: Dulce Helena Siqueira Silva
Banca: Roberta Cornello Ferreira Nocelli
Banca: Maria Elena de Lima Perez Garcia
Resumo: Consideráveis esforços estão sendo feitos no sentido de isolar e identificar compostos neuroativos presentes em secreções de Artrópodes, resultando na descoberta de muitos peptídeos e moléculas pequenas com ação bloqueadora de receptores de glutamato e/ou canais de cálcio. Tendo isso em vista, a secreção de muitos desses animais tornaram-se ferramentas úteis para os estudos fisiológicos de diversas funções neurais, e muitos dos compostos neurotóxicos produzidos por suas secreções agressivas/defensivas podem se tornar modelos estruturais e funcionais para o desenvolvimento racional de agentes neuroprotetores para diversas desordens neurológicas. Assim, os venenos das vespas Agelaia pallipes pallipes, Agelaia vicina e Polybia paulista foram fracionados em HPLC, e as frações puras, mais abundantes, foram investigadas por espectrometria de massas e ressonância magnética nuclear para elucidação estrutural das mesmas; e posteriormente, estas frações foram submetidas a diversos ensaios para a determinação de suas atividades biológicas, principalmente daquelas atividades relacionadas à neurotoxicidade/ neuroproteção, tanto em artrópodes como em mamíferos. Através desta abordagem foi possível identificar alguns dos compostos de baixas massas moleculares mais abundantes nos venenos das vespas sociais citadas acima, como a Histamina, a Serotonina, que são comuns a todos estes venenos e possuem como principal função, a potencialização da dor e inflamação, além de outros efeitos no SNC de vertebrados. Também foi isolado um novo tripeptídeo de sequência Gly-Leu-Leu-OH a partir do veneno da vespa A. vicina, cuja função ainda não é conhecida e a síntese e ensaios biológicos do mesmo serão realizados em algumas ramificações dessa tese. A partir do veneno da vespa P. paulista foi isolada 2-feniletilamina, um composto... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Considerable research efforts have been mounted to isolate and identify neuroactive compounds in Arthropods secretions, resulting in the discovery of many peptides and small molecules which block glutamate receptors and/or calcium channels. Thus, the secretion of many of these animals proved to be useful tools for physiological studies of neuronal function, and several of the neurotoxic compounds produced by their defensive/aggressive secretions may become structural and functional models for the rational development of neuroprotective agents for different neurological disorders. Thus, the venoms of Agelaia pallipes pallipes, Agelaia vicina e Polybia paulista were fractionated in a HPLC system, and the most abundant and pure fractions were investigated by Mass Spectrometry and Nuclear Magnetic Resonance for structural elucidation, and then, these compounds were assayed for biological activity determination, focusing the neuronal activities for these compounds, both in Arthropods and mammals. Considering this approach, it was possible to identify some of the most low molecular mass compounds in the venoms of the social wasps cited above, such as: Histamine and Serotonin, which were common to all of these species, presenting as main function to increase the pain and inflammation, in addition to other effects in the CNS of vertebrates. It was also isolated from the venom of the wasp A. vicina a new tripetide which had its sequence determined as Gly-Leu-Leu- OH, and whose function has not been determined. From the venom of the wasp P. paulista it was isolated 2-phenylethylamine, an amphetamine-like compound, whose occurrence is uncommon in animal venoms, and which has stimulatory effects on the CNS primarily related to dopaminergic neurotransmission. It caused effects of paralysis on Africanized bees, probably by hyper-excitability in the CNS of this organism. We have also observed locomotor... (Complete abstract click electronic access below)
Doutor

O metaboloma é definido como a coleção qualitativa e quantitativa de todos os metabólitos de baixa massa molecular presentes nas células, os quais participam de reações bioquímicas necessárias para a manutenção, crescimento e fisiologia celular. A avaliação metabolômica permite o delineamento do processo bioquímico de sistemas a fim de ampliar o entendimento de como as patologias se manifestam. A Espectroscopia de Ressonância Magnética Nuclear (RMN) é usada para investigar uma variedade de processos biológicos em diversos sistemas. A magnética aplicada a células e biópsias de tecido intacto de melanoma murino B16F10 contribuiu para a caracterização bioquímica de biomarcadores das diferentes fases de progressão tumoral do melanoma murino B16F10. Os resultados obtidos neste estudo permitiram a identificação de 33 metabólitos possíveis, envolvidos na carga lipídica e no metabolismo secundário da via glicolítica, que favorecem o crescimento e a progressão tumoral. A presença da taurina, prolina, serina, fenilalanina, que aumentaram quantitativamente, são possíveis marcadores da invasão, progressão e metastatização. A análise quantitativa desses metabólitos mostrou diferença significativa em 11 compostos, dos quais 9 estão diretamente envolvidos na expressão das respostas proliferativas, de morte celular e angiogênese, nos diferentes períodos de crescimento do melanoma B16F10, avaliados neste estudo. Desta forma, os achados obtidos neste estudo, quando associados no futuro a outros fatores, poderão ser úteis no diagnóstico e auxiliar na escolha terapêutica alvo com maior especificidade e menores efeitos colaterais. RMN pode ter um importante impacto na monitorização de metabólitos em células e tecidos tumorais, possibilitando a detecção mais precoce de tumores malignos, em suma, através da combinação de métodos de ressonância magnética.
The metabolome is defined as the qualitative and quantitative collection of all low weight molecular metabolites in cells that participate in biochemical reactions necessary for the maintenance, growth and physiology of cell. The metabolomic evaluation allows the design of systems of biochemical process in order to broaden the understanding of how diseases manifest. The Nuclear Magnetic Resonance Spectroscopy (NMR) is used for investigating a variety of biological processes in several systems. The magnetics applied to cell and tissue biopsies intact murine melanoma B16F10 contributed to the biochemical characterization of biomarkers of different stages of tumor progression of murine melanoma B16F10. The results obtained in this study allowed the identification of 33 potential metabolites involved in lipid content in the secondary metabolism of the glycolytic pathway, which promote growth and tumor progression. The presence of taurine, proline, serine, phenylalanine, which quantitatively increased, is possibly markers of invasion and metastasis progression. Quantitative analysis of these metabolites showed a significant difference in 11 compounds, of which 9 are directly involved in the expression of proliferative responses, cell death and angiogenesis in different periods of growth of B16F10 melanoma, evaluated in this study. Thus, the findings from this study, when associated in the future with other factors, may be useful in the diagnosis and may assist in choosing therapeutic target with greater specificity and fewer side effects. NMR may have a significant impact on monitoring metabolites in tumor cells and tissues, allowing for earlier detection of malignant tumors; in short, by combining MRI methods.

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Consideráveis esforços estão sendo feitos no sentido de isolar e identificar compostos neuroativos presentes em secreções de Artrópodes, resultando na descoberta de muitos peptídeos e moléculas pequenas com ação bloqueadora de receptores de glutamato e/ou canais de cálcio. Tendo isso em vista, a secreção de muitos desses animais tornaram-se ferramentas úteis para os estudos fisiológicos de diversas funções neurais, e muitos dos compostos neurotóxicos produzidos por suas secreções agressivas/defensivas podem se tornar modelos estruturais e funcionais para o desenvolvimento racional de agentes neuroprotetores para diversas desordens neurológicas. Assim, os venenos das vespas Agelaia pallipes pallipes, Agelaia vicina e Polybia paulista foram fracionados em HPLC, e as frações puras, mais abundantes, foram investigadas por espectrometria de massas e ressonância magnética nuclear para elucidação estrutural das mesmas; e posteriormente, estas frações foram submetidas a diversos ensaios para a determinação de suas atividades biológicas, principalmente daquelas atividades relacionadas à neurotoxicidade/ neuroproteção, tanto em artrópodes como em mamíferos. Através desta abordagem foi possível identificar alguns dos compostos de baixas massas moleculares mais abundantes nos venenos das vespas sociais citadas acima, como a Histamina, a Serotonina, que são comuns a todos estes venenos e possuem como principal função, a potencialização da dor e inflamação, além de outros efeitos no SNC de vertebrados. Também foi isolado um novo tripeptídeo de sequência Gly-Leu-Leu-OH a partir do veneno da vespa A. vicina, cuja função ainda não é conhecida e a síntese e ensaios biológicos do mesmo serão realizados em algumas ramificações dessa tese. A partir do veneno da vespa P. paulista foi isolada 2-feniletilamina, um composto...
Considerable research efforts have been mounted to isolate and identify neuroactive compounds in Arthropods secretions, resulting in the discovery of many peptides and small molecules which block glutamate receptors and/or calcium channels. Thus, the secretion of many of these animals proved to be useful tools for physiological studies of neuronal function, and several of the neurotoxic compounds produced by their defensive/aggressive secretions may become structural and functional models for the rational development of neuroprotective agents for different neurological disorders. Thus, the venoms of Agelaia pallipes pallipes, Agelaia vicina e Polybia paulista were fractionated in a HPLC system, and the most abundant and pure fractions were investigated by Mass Spectrometry and Nuclear Magnetic Resonance for structural elucidation, and then, these compounds were assayed for biological activity determination, focusing the neuronal activities for these compounds, both in Arthropods and mammals. Considering this approach, it was possible to identify some of the most low molecular mass compounds in the venoms of the social wasps cited above, such as: Histamine and Serotonin, which were common to all of these species, presenting as main function to increase the pain and inflammation, in addition to other effects in the CNS of vertebrates. It was also isolated from the venom of the wasp A. vicina a new tripetide which had its sequence determined as Gly-Leu-Leu- OH, and whose function has not been determined. From the venom of the wasp P. paulista it was isolated 2-phenylethylamine, an amphetamine-like compound, whose occurrence is uncommon in animal venoms, and which has stimulatory effects on the CNS primarily related to dopaminergic neurotransmission. It caused effects of paralysis on Africanized bees, probably by hyper-excitability in the CNS of this organism. We have also observed locomotor... (Complete abstract click electronic access below)

Doutoramento em Química
Chapter 1 introduces the scope of the work by identifying the clinically relevant prenatal disorders and presently available diagnostic methods. The methodology followed in this work is presented, along with a brief account of the principles of the analytical and statistical tools employed. A thorough description of the state of the art of metabolomics in prenatal research concludes the chapter, highlighting the merit of this novel strategy to identify robust disease biomarkers. The scarce use of maternal and newborn urine in previous reports enlightens the relevance of this work. Chapter 2 presents a description of all the experimental details involved in the work performed, comprising sampling, sample collection and preparation issues, data acquisition protocols and data analysis procedures. The proton Nuclear Magnetic Resonance (NMR) characterization of maternal urine composition in healthy pregnancies is presented in Chapter 3. The urinary metabolic profile characteristic of each pregnancy trimester was defined and a 21-metabolite signature found descriptive of the metabolic adaptations occurring throughout pregnancy. 8 metabolites were found, for the first time to our knowledge, to vary in connection to pregnancy, while known metabolic effects were confirmed. This chapter includes a study of the effects of non-fasting (used in this work) as a possible confounder. Chapter 4 describes the metabolomic study of 2nd trimester maternal urine for the diagnosis of fetal disorders and prediction of later-developing complications. This was achieved by applying a novel variable selection method developed in the context of this work. It was found that fetal malformations (FM) (and, specifically those of the central nervous system, CNS) and chromosomal disorders (CD) (and, specifically, trisomy 21, T21) are accompanied by changes in energy, amino acids, lipids and nucleotides metabolic pathways, with CD causing a further deregulation in sugars metabolism, urea cycle and/or creatinine biosynthesis. Multivariate analysis models´ validation revealed classification rates (CR) of 84% for FM (87%, CNS) and 85% for CD (94%, T21). For later-diagnosed preterm delivery (PTD), preeclampsia (PE) and intrauterine growth restriction (IUGR), it is found that urinary NMR profiles have early predictive value, with CRs ranging from 84% for PTD (11-20 gestational weeks, g.w., prior to diagnosis), 94% for PE (18-24 g.w. pre-diagnosis) and 94% for IUGR (2-22 g.w. pre-diagnosis). This chapter includes results obtained for an ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) study of pre-PTD samples and correlation with NMR data. One possible marker was detected, although its identification was not possible. Chapter 5 relates to the NMR metabolomic study of gestational diabetes mellitus (GDM), establishing a potentially predictive urinary metabolic profile for GDM, 2-21 g.w. prior to diagnosis (CR 83%). Furthermore, the NMR spectrum was shown to carry information on individual phenotypes, able to predict future insulin treatment requirement (CR 94%). Chapter 6 describes results that demonstrate the impact of delivery mode (CR 88%) and gender (CR 76%) on newborn urinary profile. It was also found that newborn prematurity, respiratory depression, large for gestational age growth and malformations induce relevant metabolic perturbations (CR 82-92%), as well as maternal conditions, namely GDM (CR 82%) and maternal psychiatric disorders (CR 91%). Finally, the main conclusions of this thesis are presented in Chapter 7, highlighting the value of maternal or newborn urine metabolomics for pregnancy monitoring and disease prediction, towards the development of new early and non-invasive diagnostic methods.
O Capítulo 1 descreve o enquadramento deste trabalho identificando as doenças pré-natais relevantes e os métodos de diagnóstico actualmente disponíveis. É depois apresentada a metodologia seguida, assim como uma breve introdução dos princípios dos métodos analíticos e estatísticos aplicados. O capítulo é concluído com uma descrição do estado da arte na área de metabolómica em investigação pré-natal, identificando o mérito desta inovadora estratégia para a identificação de marcadores robustos de doenças pré-natais. A relevância deste trabalho torna-se clara através do escasso uso de urina materna e do recém-nascido em trabalhos anteriores. O Capítulo 2 descreve os procedimentos experimentais utilizados neste trabalho, incluindo condições de amostragem, recolha e preparação das amostras, protocolos de aquisição e de tratamento dos dados. A caracterização da composição da urina materna, através de espectroscopia de Ressonância Magnética Nuclear (RMN) de protão é apresentada no Capítulo 3. Define-se o perfil metabólico urinário característico para cada trimestre de gravidez, tendo sido encontrado um conjunto de 21 metabolitos descritivo das alterações metabólicas ocorridas ao longo da gravidez. 8 metabolitos foram encontrados a variar com a gravidez, pela primeira vez, tendo sido confirmadas variações metabólicas conhecidas. É ainda estudado o efeito do não-jejum (usado neste trabalho) como possível factor de confusão. O Capítulo 4 apresenta o estudo metabolómico de urina materna do 2º trimestre para o diagnóstico de doenças fetais e previsão de complicações mais tarde desenvolvidas. Este estudo compreende a aplicação de um método de selecção de variáveis desenvolvido no âmbito desta tese. Observou-se que as malformações fetais (e, especificamente, do sistema nervoso central, SNC) e as cromossomopatias (e, especificamente, a trissomia 21, T21) são acompanhadas por alterações nos metabolismos energético, dos aminoácidos, lípidos e nucleótidos, enquanto que as cromossomopatias mostraram ser acompanhadas por uma desregulação adicional dos metabolismos dos açúcares, ciclo da ureia e/ou biossíntese da creatinina. A validação dos modelos multivariados revelou taxas de classificação (CR) de 84% para malformações (87%, SNC) e 85% para CD (94%, T21). Para o parto pré-termo, pré-eclampsia (PE) e restrição de crescimento intrauterino (RCIU) observaram-se perfis que podem ajudar à previsão precoce, com CR 84% para pretermo (11-20 semanas de gestação, g.w. pré-diagnóstico), 94% para PE (18-24 g.w. pré-diagnóstico) e 94% para RCIU (2-22 g.w. pré-diagnóstico). Este capítulo inclui resultados obtidos por cromatografia líquida de ultra eficiência acoplada a espectrometria de massa (UPLC-MS) para pré-pretermo e correlação com os dados de RMN. Um possível composto marcador foi detectado mas a sua identificação não foi possível. O Capítulo 5 descreve o estudo metabolómico por RMN da diabetes mellitus gestacional (DMG), estabelecendo-se um perfil metabólico potencialmente preditivo da doença (CR 83%, 2-21 g.w. pré-diagnóstico). Verificou-se ainda que o espectro de RMN contém informação sobre o fenótipo individual, capaz de prever a necessidade futura de tratamento com insulina (CR 94%). No Capítulo 6 demonstra-se o impacto do tipo de parto (CR 88%) e género do bebé (CR 76%) no perfil da urina do recém-nascido. Verificou-se ainda que a prematuridade, depressão respiratória, crescimento grande para a idade gestacional e malformações induzem perturbações metabólicas relevantes (CR 82-92%), assim como algumas doenças maternas como a DMG (CR 82%) e doenças psiquiátricas (91% CR). Finalmente, no Capítulo 7 apresentam-se as principais conclusões deste trabalho, enfatizando o potencial da metabolómica de urina materna e do bebé para o acompanhamento da gravidez e previsão de doenças, visando o desenvolvimento de novos métodos de diagnóstico precoce e não-invasivo.

From the Helichrysum genus 600 species occur in Africa of which 244 species are found in South Africa. The most commonly used Helichrysum species for medicinal purposes are H. cymosum, H. odoratissimum, H. petiolare and H. nudifolium. The medicinal uses include the treatment of coughs, colds, fever, infection, headaches, menstrual pain and are very popular for wound dressing. Previous published research has shown that H. aureonitens has antiviral properties against Herpes simplex virus type 1 (HSV-1). In this study, further investigation into the Helichrysum species was undertaken, to establish the active constituents responsible for anti-HSV activity using a metabolomics approach. The cytotoxicity of 12 Helichrysum species was investigated and ranged from <3.125 μg/ml to 277.8 μg/ml on the vero cell line. The 12 Helichrysum species also showed various levels of antiviral activity against HSV, with both the water-methanol and chloroform extracts of H. adenocarpum subsp. adenocarpum being the most active extract at 25 μg/ml. In this study the activity of Helichrysum species against HIV-1 RT was also investigated. Helichrysum populifolium was the most active extract, inhibiting the HIV-1 RT enzyme by 63.78 % at 200 μg/ml. The bioactivity data and the spectral nuclear magnetic resonance (NMR) data of al the Helichrysum species from this study was analysed using the SIMCA-P software to discriminate between the different species on the basis of their bioactivity and chemical composition. The samples did not group well on Principal Component Analysis (PCA) but did separate well using the Orthogonal Projection to Latent Structure – Discriminate Analysis (OPLS-DA) on the basis of their activity and NMR spectra data. From the OPLS scoring plots analysis, contribution plots were created which indicated regions responsible for the difference between the species, with these regions being investigated to identify the bioactive constituents. It was thus possible to use metabolomics to discriminate between samples on the basis of their activity and show that it could probably be used in future as a tool to identify active ingredients in medicinal plants and accelerate drug discovery. Copyright
Dissertation (MSc)--University of Pretoria, 2009.
Plant Science
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A l’heure actuelle aucun consensus n’existe sur l’utilisation des substrats énergétiques lors d’un exercice en altitude. Certaines études ont montré une utilisation accrue des glucides en altitude comparée à la plaine mais les intensités d’exercices utilisées sont discutables et l’utilisation de méthodes biochimiques traditionnelles ont permis de doser qu’un nombre restreint de molécules. Aujourd’hui grâce à la métabolomique, il est possible d’analyser les variations d’un grand nombre de métabolites simultanément. Le but de cette thèse est d’étudier l’incidence de l’altitude modérée sur l’utilisation des substrats énergétiques à l’effort à l’aide de la métabolomique par résonnance magnétique nucléaire du proton. Des échantillons de plasmas et d’urines ont été collectés lors d’exercices d’endurance en plaine et en altitude modérée chez des sujets non acclimatés. Nos premiers résultats, dans les plasmas, ont montré une baisse de la glycémie et une utilisation accrue des acides aminés ramifiés entre avant et après un exercice d’endurance en altitude, ce qui n’a pas été observé en plaine. Ces résultats ont ensuite été confirmé lors d’un exercice d’endurance jusqu’à épuisement. De plus, nous avons montré que l’utilisation des urines permet de mettre en avant les résultats obtenus dans les plasmas, ce qui est très encourageant pour la compréhension des adaptations métaboliques en altitude par des méthodes non invasives. Pour finir, nous avons utilisé une méthode statistique innovante appelée « analyse en composantes communes et poids spécifiques ». Les résultats ont permis d’observer les variabilités communes entre les paramètres physiologiques mesurés et les variations des métabolites plasmatiques
Although it is known that altitude impairs performance in endurance sports, there is no consensus on the involvement of energy substrates in this process. Some studies have shown an increased use of carbohydrates at altitude compared at plain but the intensities of exercises used are debatable and the use of traditional biochemical methods allowed to dose only a limited number of molecules. Today, thanks to metabolomics, it is possible to analyze the variations of a large number of metabolites simultaneously. The aim of this thesis is to investigate the incidence of moderate altitude on the use of energy substrates on stress using proton nuclear magnetic resonance metabolomics. Plasma and urine samples were collected during endurance exercises at plain and at moderate altitude in non-acclimatized subjects. Our first results in plasma showed decreased blood glucose and increased use of branched amino acids between before and after endurance exercise at altitude, which was not observed at plain. These results were then confirmed during an endurance exercise until exhaustion. Moreover, we have shown that the use of urine allows to highlight the results obtained in the plasmas, which is very encouraging for the understanding of the metabolic adaptations at altitude by noninvasive methods. Finally, we used an innovative statistical method called “ common components and specific weights analysis”. The results allowed us to observe the common variability between the measured physiological parameters and the variations of the plasma metabolites

La métabonomique est une approche de choix pour l’identification de biomarqueurs d’intérêts pour le diagnostic de pathologies mais aussi pour l’amélioration de notre compréhension des processus physiopathologiques. La métabonomique offre de nouvelles perspectives en épidémiologie moléculaire, objet principale de cette thèse. Nous avons appliqué l’approche métabonomique par RMN à haut champ à l’analyse de sérums sanguins issus de la cohorte prospective EPIC (European Prospective Investigation into Cancer and nutrition) dans le but d’identifier des biomarqueurs de la survenue du cancer du foie et du cancer du pancréas. L’analyse statistique des profiles métaboliques des sérums obtenus par RMN à 800MHz a permis de mettre en évidence une signature métabolique associée à l’occurrence des hépatocarcinomes (HCC) à cinq ans avant diagnostic en moyenne. L’analyse stratifiée des données a révélé des biomarqueurs précoces mais aussi des biomarqueurs de l’étiologie des HCC. L’analyse métabonomique portée sur le cancer du pancréas n’a à l’inverse pas été concluante. Des méthodes pertinentes pour l’analyse des cohortes épidémiologiques par métabonomique ont été développées, telle qu’une méthode de correction d’effet batch rendant possible la comparaison de données RMN acquises au cours d’une longue période de temps. La méthode statistique PCPR2 développée permet de quantifier l’impact de différents facteurs sur les données métabonomique afin d’en révéler les sources de variations systématiques. D’autre part, l’approche métabonomique permet également l’investigation de questions biologiques plus fondamentales. Cette thèse offre une approche de génomique fonctionnelle à l’étude des cibles métaboliques du récepteur aux hormones thyroïdiennes TRβ dans le foie. L’analyse des données HR-MAS de tissus de foie intacts complémentée par l’analyse d’extraits hépatiques sur un modèle de souris a permis d’éclaircir le rôle de ce récepteur nucléaire
Metabonomics is a recent approach that enables not only to identify relevant biomarkers for disease diagnosis but also to improve our understanding of biological processes by gaining insight into metabolism. This thesis is mainly dedicated to the application of metabonomics to molecular epidemiology. High-field NMR metabonomic approach was applied to the analysis of serum samples from the large prospective cohort EPIC (European Prospective Investigation into Cancer and nutrition) to identify biomarkers of liver cancer and pancreatic cancer occurrence. The statistical analysis of NMR serum metabolic profiles obtained at 800 MHz enabled to highlight a metabolic signature associated with the occurrence of hepatocellular carcinoma (HCC), in average five years before diagnosis. The stratified analysis revealed both early and etiologic biomarkers of HCC. The NMR metabonomic analysis of the pancreatic cancer did not reveal any metabolic signature of this cancer. Moreover, relevant methods to allow the NMR metabonomic analysis of epidemiological cohort were developed. This thesis proposes a method to correct data for batch effect, making possible the comparison of NMR data recorded in a long period of time. The statistical method PC-PR2 developed enables the quantification of the contribution of different factors onto metabonomic data to reveal systematic variation sources. In addition, the metabonomic approach is also suitable to address specific biological questions by providing a new read-out of the metabolism. Functional genomics by NMR metabonomics was used in this thesis to study the metabolic targets of the thyroid hormone nuclear receptor TRβ in the liver. The analysis of HR-MAS data obtained on intact liver tissue in addition to the analysis of NMR data of liver extracts from a mice model enabled to better understand the role of this nuclear receptor

Burn injury is a highly traumatic event for any infant or child. The degree of burn severity often determine the treatment operations and the extent of later scar formation, which may require long-term surgical remediation or skin grafting. This investigation quantitatively characterises the biochemical composition of burn blister fluid from paediatric patients using advanced analytical techniques. The correlation of the abundance of proteins and metabolic molecules were explored by statistical and bioinformatics methods. Thus, this study is able to provide a timely and objective measurement that may reflect the burn wound microenvironment and assist clinical diagnosis.

Doutoramento em Química
The main scope of this work was to evaluate the metabolic effects of anticancer agents (three conventional and one new) in osteosarcoma (OS) cells and osteoblasts, by measuring alterations in the metabolic profile of cells by nuclear magnetic resonance (NMR) spectroscopy metabolomics. Chapter 1 gives a theoretical framework of this work, beginning with the main metabolic characteristics that globally describe cancer as well as the families and mechanisms of action of drugs used in chemotherapy. The drugs used nowadays to treat OS are also presented, together with the Palladium(II) complex with spermine, Pd2Spm, potentially active against cancer. Then, the global strategy for cell metabolomics is explained and the state of the art of metabolomic studies that analyze the effect of anticancer agents in cells is presented. In Chapter 2, the fundamentals of the analytical techniques used in this work, namely for biological assays, NMR spectroscopy and multivariate and statistical analysis of the results are described. A detailed description of the experimental procedures adopted throughout this work is given in Chapter 3. The biological and analytical reproducibility of the metabolic profile of MG-63 cells by high resolution magic angle spinning (HRMAS) NMR is evaluated in Chapter 4. The metabolic impact of several factors (cellular integrity, spinning rate, temperature, time and acquisition parameters) on the 1H HRMAS NMR spectral profile and quality is analysed, enabling the definition of the best acquisition parameters for further experiments. The metabolic consequences of increasing number of passages in MG-63 cells as well as the duration of storage are also investigated. Chapter 5 describes the metabolic impact of drugs conventionally used in OS chemotherapy, through NMR metabolomics studies of lysed cells and aqueous extracts analysis. The results show that MG-63 cells treated with cisplatin (cDDP) undergo a strong up-regulation of lipid contents, alterations in phospholipid constituents (choline compounds) and biomarkers of DNA degradation, all associated with cell death by apoptosis. Cells exposed to doxorubicin (DOX) or methotrexate (MTX) showed much slighter metabolic changes, without any relevant alteration in lipid contents. However, metabolic changes associated with altered Krebs cycle, oxidative stress and nucleotides metabolism were detected and were tentatively interpreted at the light of the known mechanisms of action of these drugs. The metabolic impact of the exposure of MG-63 cells and osteoblasts to cDDP and the Pd2Spm complex is described in Chapter 6. Results show that, despite the ability of the two agents to bind DNA, the metabolic consequences that arise from exposure to them are distinct, namely in what concerns to variation in lipid contents (absent for Pd2Spm). Apoptosis detection assays showed that, differently from what was seen for MG-63 cells treated with cDDP, the decreased number of living cells upon exposure to Pd2Spm was not due to cell death by apoptosis or necrosis. Moreover, the latter agent induces more marked alterations in osteoblasts than in cancer cells, while the opposite seemed to occur upon cDDP exposure. Nevertheless, the results from MG-63 cells exposure to combination regimens with cDDP- or Pd2Spm-based cocktails, described in Chapter 7, revealed that, in combination, the two agents induce similar metabolic responses, arising from synergy mechanisms between the tested drugs. Finally, the main conclusions of this thesis are summarized in Chapter 8, and future perspectives in the light of this work are presented.
Este trabalho teve como principal objetivo estudar os efeitos metabólicos de alguns fármacos (três fármacos convencionais e um em desenvolvimento) em células de osteossarcoma (OS) e osteoblastos, através da medição de alterações dos perfis metabólicos celulares por metabolómica usando espectroscopia de Ressonância Magnética Nuclear (RMN). O Capítulo 1 apresenta um enquadramento teórico deste trabalho, começando por identificar as principais características metabólicas que descrevem o cancro em geral, assim como as famílias e mecanismos de ação dos fármacos usados no seu tratamento. São ainda apresentados os fármacos usados atualmente na quimioterapia do OS, bem como o complexo de Paládio (II) com espermina, Pd2Spm, com potencial atividade anticancerígena. Seguidamente, é explicada a estratégia da metabolómica celular e apresentado o estado da arte de estudos metabolómicos do efeito de agentes anticancerígenos em células. No Capítulo 2, apresentam-se os princípios das técnicas analíticas usadas neste trabalho, nomeadamente ensaios biológicos, espectroscopia de RMN e análise multivariada e estatística dos resultados. Os detalhes e procedimentos experimentais relativos aos métodos usados são descritos no Capítulo 3. O estudo da reprodutibilidade analítica e biológica do perfil metabólico de células MG-63 medido por RMN de alta resolução e rotação segundo o ângulo mágico (HRMAS) é apresentado no Capítulo 4. Avalia-se o impacto de vários fatores (integridade celular, velocidade de rotação da amostra, temperatura, duração e parâmetros de aquisição) nas características e qualidade do espectro de RMN HRMAS de 1H, definindo-se então os parâmetros de aquisição dos espectros a adquirir subsequentemente. Avaliam-se também os efeitos do nº de passagens celulares e do tempo de armazenamento no perfil metabólico de células MG-63. O Capítulo 5 descreve o impacto metabólico de fármacos convencionais usados atualmente na quimioterapia do OS, estudado por metabolómica por RMN de células lisadas e análise de extratos celulares aquosos. Os resultados mostram que as células MG-63 tratadas com cisplatina (cDDP) sofrem um aumento dramático do teor de lípidos, alterações dos níveis de constituintes dos fosfolípidos (compostos de colina) e de indicadores de degradação do DNA, associados a fenómenos de apoptose. Nas células expostas a doxorrubicina (DOX) ou a metotrexato (MTX) foram identificadas alterações metabólicas mais ténues, com a quase total ausência de alterações no teor de lípidos. Foram também detetadas alterações em metabolitos relacionados com o ciclo de Krebs, stress oxidativo e metabolismo de nucleótidos, interpretadas tentativamente à luz dos mecanismos de ação de cada um dos fármacos. O impacto metabólico da exposição de células MG-63 e osteoblastos a cDDP e ao complexo de Pd2Spm é apresentado no Capítulo 6. Os resultados mostram que, apesar de ambos os fármacos poderem ligar ao DNA, as alterações metabólicas que decorrem da sua ação são muito distintas, nomeadamente no que respeita às variações nos teores de lípidos (ausentes para Pd2Spm). Ensaios de medição de apoptose mostraram que, contrariamente ao verificado para células MG-63 expostas a cDDP, a redução do número de células por exposição a Pd2Spm não se deve a fenómenos de morte celular por apoptose ou necrose. Além disso, este último complexo exerce um efeito mais marcado em osteoblastos do que nas células cancerígenas, o inverso parecendo acontecer com a exposição a cDDP. Contudo, os resultados da exposição de células MG-63 a regimes de tratamento combinado com base em cocktails de cDDP ou Pd2Spm, descritos no Capítulo 7, mostram que, em combinação, os dois agentes induzem respostas metabólicas semelhantes entre si, decorrentes de mecanismos de sinergia entre fármacos. Finalmente, sumariam-se no Capítulo 8 as conclusões deste trabalho e apontam-se perspetivas de trabalho futuro.

Base teórica: Artrite reumatoide (AR) é uma doença autoimune que afeta as articulações e progride de maneira simétrica e erosiva. Além dos achados articulares, pode ocorrer de perda muscular e síndrome da caquexia. Atualmente, não existe um marcador que sirva de preditor da síndrome de caquexia reumatoide. Estudos metabolômicos em pacientes com AR demonstram uma complexidade em encontrar um biomarcador para caquexia. Ademais, não há modelo experimental de caquexia descrito na literatura, mas o modelo de artrite induzida por colágeno (CIA) possui potencial de ser modelo de caquexia reumatoide. A partir deste modelo, pode-se fazer a busca por biomarcadores de caquexia reumatoide via metabolômica. Objetivo: Avaliar o modelo de CIA como modelo experimental de caquexia reumatoide. Avaliar o perfil metabólico da urina no modelo de CIA e correlacionar com parâmetros clínicos de caquexia reumatoide em busca de possíveis biomarcadores. Métodos: Camundongos machos DBA/1J foram induzidos (CIA; n=13) no dia zero e receberam reforço 18 dias após, e grupo mantidos saudáveis sem indução (CO; n=11). Nos dias 0, 18, 25, 35, 45, 55 e 65 após a indução, foram realizados: coleta de urinas; teste de desempenho físico; teste de locomoção espontânea; teste de força; medida do volume do edema da pata traseira; avaliação do escore clínico; pesagem; e avaliação da ingestão alimentar. Após os 65 dias, os animais foram eutanasiados e tecidos musculares (gastrocnêmio – GA; e tibial anterior – TA) foram dissecados para pesagem e realização da razão sarcoplasmática. Os dados foram analisados por ANOVA de duas vias, seguido de Bonferroni, ou teste t de Pearson, com significância a partir de um p<0,05. A urina coletada foi submetida à ressonância nuclear magnética (1D e 2D J-res). Os metabolitos foram identificados via Chenomx (1D) e pelo Birmingham Metabolite Library (BML; 2D J-res). Utilizou-se a o modelo estatístico de PCA, PLSDA e PLSR para criar ranqueamento de metabolitos (significância a partir de um p<0,05). Analizou-se as rotas metabólicas via Metaboanalyst a partir do ranqueamento de metabólitos obtidos. Os metabólitos obtidos foram filtrados para rotas metabólicas que ocorrem no músculo para identificação de potenciais biomarcadores de perda muscular. Resultados: O grupo CIA apresentou redução de até 24% na locomoção espontânea, de até 66% na força e de até 24% no teste de desempenho físico após 35 dias da indução, bem como redução no peso do GA (24%) e TA (25%), e relação sarcoplasmática (22 e 23%, respectivamente) em relação ao grupo CO. Os modelos estatísticos de PCA, PLSDA e PLSR, e o filtro pelas rotas metabólicas relacionadas com o músculo geraram uma lista de 28 metabólitos e relacionados com o desenvolvimento da doença, sendo eles: 3-metilhistidina, 4-aminobutirato, acetilcolina, arginina, aspartato, carnosina, creatina, creatinina, glutamina, histamina, histidina, isoleucina, leucina, metionina, lisina, mio-inositol, dimetilglicina, acetilalanina, acetilmetionina, pantotenato, fenilalanina, fosfocolina, fosfocreatina, piridoxina, sarcosina, succinilacetona, tiamina, e urocanato. Conclusão: Em concordância com os resultados de redução nos parâmetros de: massa muscular, locomoção espontânea, força e desempenho físico, somando-se a ausência de anorexia bem como mudança no peso, o modelo animal de CIA representa um modelo experimental próprio para caquexia reumatoide. A análise do perfil metabólico deste modelo permite sugerir 28 metabólitos relacionados ao processo de perda muscular, que podem vir a ser biomarcadores de caquexia reumatoide, objetivando prognóstico, diagnóstico e acompanhamento da síndrome. Destes metabólitos, os principais são pertencentes ao metabolismo de: histidina; arginina e prolina; glicina, serina e treonina; fosfocreatina, bem como outros aminoácidos e vitaminas do complexo B.
Background: Rheumatoid Arthritis (RA) is an autoimmune disease that affects the joints and has a symmetric development and it is erosive. Besides joint damage, it can develop muscle loss progress into cachexia syndrome. Currently, there is no marker that can predict it development in rheumatoid patients. Metabolomics in RA have shown to be complex to find out a biomarker for this syndrome. Also, there is no experimental model of cachexia described in literature yet; however the collageninduced arthritis (CIA) animal model seems to be a feasible model for rheumatoid cachexia. With this model, the research for a biomarker of rheumatoid cachexia can be done by metabolomics. Objectives: It will be evaluated if the CIA animal model can be also an animal model of rheumatoid cachexia. Afterwards, it will be evaluated a metabolic profile from urine of this animal model and correlate with clinical signs of rheumatoid cachexia to find out plausible biomarkers of it. Methods: Male DBA/1J mice were submitted to CIA (n=13), immunization occurred at day zero and a booster was performed 18 days after, and a healthy group with no induction (CO; n=11). At the 0,18, 25, 35, 45, 55 and 65 days after the first injection, it was done: urine collection; physical performance test; free exploratory locomotion test; strength test; hindpaw edema volume measurement; follow up disease development; weighted; and food intake. After the 65 days, animals were euthanized and muscle (gastrocnemious – GA; and tibial anterior – TA) were dissected, and weighted for sarcoplasmic ratio. Data were analyzed by two-way ANOVA followed by Bonferroni post hoc, and t-test of Pearson, and statistical critical limit was set for p<0.05. The collected urine was used for nuclear magnetic resonance (1D and 2D J-res). Metabolites were identified by Chenomx (1D) and by the Birmingham Metabolite Library (BML; 2D J-res). Statistical model were performed using PCA, PLSDA and PLSR to create a ranking list of the metabolites (statistical critical limit was set for p<0.05). It was analyzed the metabolic pathway by Metaboanalyst from the data of metabolite ranking list. Then, the metabolite list was filtered by the metabolic pathways that take place in muscle tissue, in order to identify plausible biomarkers of muscle loss. Results: CIA group has shown reduction in up to 24% of free locomotion fatigue, up to 66% of strength and up to 24% of endurance physical performance after 35 days of the induction, as well as a decrease in GA (24%) and TA (25%) weight, and sarcoplasmic ratio also reduced (22 and 23%, respectivamente) related to CO group. The PCA, PLSDA and PLSR statistical models, and the filter by metabolic pathways related to muscle provided a list of 28 metabolites related to disease development, as can be listed: 3-methylhistidine, 4-aminobutyrate, acetylcholine, arginine, aspartate, carnosine, creatine, creatinine, glutamine, histamine, histidine, isoleucine, leucine, methionine, lysine, myo-inositol, dimethylglycine, acetylalanine, acetylmethionine, pantothenate, phenylalanine, phosphocholine, phosphocreatine, pyridoxine, sarcosine, succinylacetone, thiamine, and urocanate. Conclusions: Accordingly with the data with reduction of: muscle mass, spontaneous locomotion, strength and physical performance, added with absence of anorexia as well as weight change, CIA animal model is a feasible experimental model for rheumatoid cachexia. Concerning the metabolic profile from this model, it can be suggested 28 metabolites related to muscle loss in which can be tested for biomarker of rheumatoid cachexia, targeting prognosis, diagnosis, and syndrome follow up. From those metabolites, the main ones are engaged to metabolism of: histidine; arginine and proline; glycine, serine and threionine; phosphorcreatine, as well as other amino acids and vitamins from B complex.

The growing world demand for renewable energy production in substitution of fossil fuels has given great prominence in the culture of sugarcane (Saccharum sp.). This has been considered the most efficient crop for energy production, as Brazil being the world's largest producer, with a production of 655.6 million tons in 2015/2016 harvest in an area of 8.5 million hectares. One of the major obstacles to the production of sugarcane is still the attack by pest and estimates that about 10% of the crop losses are caused by insects, being a sugarcane borer (Diatraea Saccharalis) the most importante pest. The plants, during its evolution, to reduce the damages caused by the attack of pests, they have developed a series of defense mechanisms, among them, physical barriers, proteins and toxic metabolites and volatile metabolic flags. Many works have been developed to decipher the mechanisms of defense of sugarcane to the attack of herbivorous insects, an attempt of genetic breeding programs and information biotechnology for the development of more resistant plants, however, many of the mechanisms still remain to be clarified. These works are mostly restricted to the study of genes and proteins and global studies of transcript and proteome analyzes of the plant. The current work proposes to perform an analysis of the metabolism of two varieties of sugarcane (RB92579 and SP791011) through direct and indirect extraction methods in response to herbivory by Diatraea saccharalis using NMR spectroscopy and multivariate statistical analysis from data by principal component analysis (PCA) and least squares analysis of discrimination (OPLS-DA). In the metabolomic analysis of sugarcane of the variety RB92579 was studied using the direct extraction method (leaves) in the 4 herbivory times (24, 48, 72 and 96 hours), only after 48, 72 and 96 hours of stress by herbivory, it was possible to get differences between the control groups and herbivore groups, which the greater timing of response was obtained in 72 hours, that indicated the increase of the primary metabolites asparagine, aspartic acid, dimethylamine, glutamic acid , isoleucine, leucine, malic acid, tyrosine and phenylalanine. The variety of sugarcane SP791011, the method of indirect extraction of the leaves of the plant was applied in times 24, 48 and 72 hours by stress induced by caterpillars of Diatraea saccharalis and, coincidentally, showed in the time 72 hours a greater number of herbivory response metabolites, which caused a depletion of aconitic acid, formic acid, asparagine, alanine and elevation of acetic acid and chlorogenic acid. Despite their different metabolic profiles in response to herbivory, the elucidated metabolites suggest the metabolic pathway of shikimic acid to produce phenylpropanoids due to the increase of tyrosine, phenylalanine in the leaves of the sugarcane variety RB92579, and increase of chlorogenic acid in the leaves of the cane. In addition to the herbivory test, it was carried out a biological assay with chlorogenic acid inserted in the artificial diet of Diatraea saccharalis caterpillars, which demonstrated a decrease in the development time of the pupae comparing with pupae of Caterpillars Control, which caused an outbreak of moths with deformations at all concentrations of chlorogenic acid used in the bioassay. These results may help in the development of sugarcane varieties more resistant to the attack by Diatraea Saccharalis.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
A crescente demanda mundial para a produção de energias renováveis em substituição aos combustíveis fósseis tem dado grande destaque à cultura da cana-de-açúcar (Saccharum sp.). Esta tem sido considerada a cultura mais eficiente para a produção de energia, tendo o Brasil como o maior produtor mundial, com uma produção de 655,6 milhões de toneladas na safra 2015/2016 em uma área de 8,5 milhões de hectares. Um dos grandes entraves à produção de cana-de-açúcar ainda é o ataque de pragas e doenças e estima-se que cerca de 10% das perdas para esta cultura sejam ocasionadas por insetos, sendo a broca da cana-de-açúcar (Diatraea saccharalis) a praga mais importante. As plantas, durante a evolução, para reduzir os danos causados pelo ataque de pragas, têm desenvolvido uma série de mecanismos de defesa, dentre eles, barreiras físicas, proteínas, metabólitos tóxicos e metabólitos voláteis sinalizadores. Muitos trabalhos têm sido desenvolvidos para decifrar os mecanismos de defesa da cana-de-açúcar ao ataque de insetos herbívoros, na tentativa de subsidiar programas de melhoramento genético e a biotecnologia de informação para o desenvolvimento de plantas mais resistentes, porém, muitos destes mecanismos ainda permanecem a ser esclarecidos. Estes trabalhos, em sua maioria, estão restritos ao estudo de genes e proteínas e a estudos globais de análises dos transcritos e do proteoma da planta. O presente trabalho propõe realizar a análise do metaboloma de duas variedades de cana-de-açúcar (RB92579 e SP791011) através dos métodos de extração direto e indireto na resposta a herbivoria por Diatraea saccharalis, utilizando espectroscopia de RMN, e processamento e estatística dos dados pelos métodos de análise de componentes principais (PCA) e análise dos mínimos quadrados parciais-análise discriminante (OPLS-DA). A análise metabolômica da cana-de-açúcar da variedade RB92579 foi realizada pelo método de extração direta (folhas) nos 4 tempos de herbivoria (24, 48, 72 e 96 horas), sendo que, apenas após 48, 72 e 96 horas sob herbivoria, foi possível haver diferenças entre os grupos controle e grupo herbivoria, no qual o tempo em que se obteve maior resposta da planta foi no tempo 72 horas, que indicou o aumento dos metabólitos primários asparagina, ácido aspártico, dimetilamina, ácido glutâmico, isoleucina, leucina, ácido málico, tirosina e fenilalanina. Já com relação a variedade de cana-de-açúcar SP 1011, aplicou-se o método de extração indireto das folhas da planta nos tempos 24, 48 e 72 horas sob estresse induzido pelas lagartas de Diatraea saccharalis e, coincidentemente, apresentou no tempo 72 horas o maior número de metabólitos de resposta a herbivoria, o que causou numa redução dos níveis de ácido cis e trans aconítico, ácido fórmico, asparagina, alanina e no aumento dos níveis de ácido acético e ácido clorogênico. Apesar de fornecerem perfis metabólicos diferentes em resposta a herbivoria, os metabólitos elucidados sugerem a via metabólica do ácido chiquímico devido ao aumento de tirosina, fenilalanina nas folhas da cana-de-açúcar da variedade RB92579, e aumento do ácido clorogênico nas folhas da cana-de-açúcar da variedade SP791011. Além do ensaio de herbivoria, foi realizado um ensaio biológico com o ácido clorogênico inserido na dieta artificial das lagartas de Diatraea saccharalis, que demonstrou uma diminuição do tempo de desenvolvimento das pupas em comparação com as pupas de lagartas controle, que provocou a eclosão das mariposas com deformações em todas as concentrações de ácido clorogênico usadas no bioensaio. Esses resultados podem ajudar no desenvolvimento de variedades de cana-de-açúcar mais resistentes ao ataque da Diatraea Saccharalis.

Mestrado em Biologia Marinha
Unlike the concern that has been growing in relation to the impacts of contamination in marine benthic populations, the responses of aquatic organisms to natural alterations, namely changes in salinity, have received little attention. In fact, salinity is one of the dominant environmental factors that most affect marine bivalves, limiting their spatial distribution in the environment. Tide combined with fresh water inputs, from rivers or heavy rainy periods, and extreme dry seasons can dramatically alter the salinity of water, causing alterations in the benthic populations, namely intertidal bivalves. Furthermore, salinity of a given environment will restrict the spatial distribution of the species, which is especially important when assessing the spread of an invasive species into a new environment. In order to understand how native (Venerupis decussata and Venerupis corrugata) and invasive (Venerupis philippinarum) clam species cope with salinity changes, physiological, biochemical and metabolomic patterns were investigated. The results obtained showed that V. decussata and V. philippinarum presented high mortality at low (0 and 7) but tolerate high (35 and 42) salinities. On the other hand, V. corrugata presented high mortality rates both at low (0 and 7) and high salinities (35 and 42). The quantification of Na and K content revealed that, along the salinity gradient, V. decussata was the species with higher ability to maintain the ionic homeostasis. The biochemical parameters also showed that V. decussata was the clam that best cope with salinity changes and V. corrugata was the most sensitive. Furthermore, the results obtained showed that clams under salinity stressful conditions can alter their biochemical mechanisms, such as increasing their antioxidant defences, to cope with the higher oxidative stress resulting from hypo and hypersaline conditions. Among the physiological and biochemical parameters analysed (glycogen, glucose and protein content; lipid peroxidation (LPO) levels, antioxidant enzymes activity; total, reduced and oxidized glutathione), superoxide dismutase (SOD), LPO and glutathione S-transferase (GST) showed to be useful biomarkers to assess salinity impacts in clams. The effects of salinity changes in the metabolic profile of the three species were also studied using 1H Nuclear Magnetic Resonance (NMR) spectroscopy of clam extracts. Multivariate analysis of the NMR spectra enabled metabolite changes to be observed in relation to clams exposure to different salinity concentrations. When exposed to low salinities, energy reserves of clams may be exhausted, increasing the osmotic imbalance, affecting the metabolic performance and increasing the oxidative stress. V. corrugata showed to be the most sensitive clam to salinity changes. The optimal salinity for V. decussata and V. philippinarum was between 21 and 28 and for V. corrugata was salinity 21. This study showed that changes in salinity have different impacts in native and invasive species
As respostas dos organismos aquáticos a alterações naturais, nomeadamente, alterações de salinidade, têm recebido pouca atenção, inversamente à preocupação que tem vindo a crescer em relação aos impactos da contaminação em populações marinhas bentónicas. De facto, a salinidade é um dos factores ambientais dominantes que mais afetam os bivalves marinhos, o que limita a sua distribuição espacial no ecossistema. As marés combinadas com entradas de água doce, de rios ou períodos de chuva longos e estações secas extremas, podem alterar drasticamente a salinidade da água, provocando alterações nas populações de bivalves bentónicos, nomeadamente intertidais. Além disso, a salinidade de um determinado ambiente irá restringir a distribuição espacial das espécies, o que é especialmente importante quando se avalia a propagação de uma espécie invasora num ambiente novo. A fim de entender como espécies nativas (Venerupis decussata e Venerupis corrugata) e invasoras (Venerupis phiippinarum) de molluscos lidam com as mudanças de salinidade, foram investigados parâmetros fisiológicos, bioquímicos e metablómicos. Os resultados obtidos mostraram que V. decussata e V. philippinarum apresentaram elevada mortalidade em salinidades baixas (0 e 7), mas toleram as salinidades mais altas (35 e 42). Por outro lado, V. corrugata apresentou elevadas taxas de mortalidade tanto em salinidades baixas (0 e 7) como em salinidades altas (35 e 42). A quantificação do teor de Na e K, revelou que ao longo do gradiente de salinidade, a V. decussata foi a espécie com maior capacidade de manter a homeostasia iónica. Os parâmetros bioquímicos também mostraram que V. decussata foi a espécie que melhor lidou com as mudanças de salinidade enquanto a V. corrugata foi a mais sensível. Além disso, os resultados obtidos mostraram que as ameijoas, sob condições adversas de salinidade, podem alterar os seus mecanismos bioquímicos, nomeadamente aumentando as suas defesas antioxidantes, para lidar com um maior stress oxidativo resultante das condições de hipo e hipersalinidade. Entre os parâmetros fisiológicos e bioquímicos analisados (glicogénio, glucose, proteinas, níveis de peroxidação lípidica (LPO), atividade de enzimas antioxidantes; glutationa total, reduzida e oxidada), LPO, superoxide dismutase (SOD) e glutathiona S-transferase (GST) mostraram ser biomarcadores úteis para avaliar os impactos de salinidade em bivalves. Os efeitos das alterações de salinidade no perfil metabólico das três espécies foram também estudados através de Ressonância Magnética Nuclear de 1H (RMN). A análise multivariada dos espectros de RMN permitiu a observação de alterações em relação à exposição de ameijoas a diferentes concentrações de salinidade. Quando expostos a baixas salinidades, as reservas energéticas destes organismos podem ser esgotadas, aumentando o desequilíbrio osmótico, afetando o desempenho metabólico e aumentando o stress oxidativo. V. corrugata mostrou ser a amêijoa mais sensível a mudanças de salinidade. O intervalo de salinidades entre 21 e 28 foi o ideal para V. decussata e V. philippinarum e a salinidade 21 foi a ideal para V. corrugata. Este estudo mostrou que as mudanças de salinidade têm impactos diferentes em espécies nativas e invasoras.

Doutoramento em Química
This thesis reports the application of metabolomics to human tissues and biofluids (blood plasma and urine) to unveil the metabolic signature of primary lung cancer. In Chapter 1, a brief introduction on lung cancer epidemiology and pathogenesis, together with a review of the main metabolic dysregulations known to be associated with cancer, is presented. The metabolomics approach is also described, addressing the analytical and statistical methods employed, as well as the current state of the art on its application to clinical lung cancer studies. Chapter 2 provides the experimental details of this work, in regard to the subjects enrolled, sample collection and analysis, and data processing. In Chapter 3, the metabolic characterization of intact lung tissues (from 56 patients) by proton High Resolution Magic Angle Spinning (HRMAS) Nuclear Magnetic Resonance (NMR) spectroscopy is described. After careful assessment of acquisition conditions and thorough spectral assignment (over 50 metabolites identified), the metabolic profiles of tumour and adjacent control tissues were compared through multivariate analysis. The two tissue classes could be discriminated with 97% accuracy, with 13 metabolites significantly accounting for this discrimination: glucose and acetate (depleted in tumours), together with lactate, alanine, glutamate, GSH, taurine, creatine, phosphocholine, glycerophosphocholine, phosphoethanolamine, uracil nucleotides and peptides (increased in tumours). Some of these variations corroborated typical features of cancer metabolism (e.g., upregulated glycolysis and glutaminolysis), while others suggested less known pathways (e.g., antioxidant protection, protein degradation) to play important roles. Another major and novel finding described in this chapter was the dependence of this metabolic signature on tumour histological subtype. While main alterations in adenocarcinomas (AdC) related to phospholipid and protein metabolisms, squamous cell carcinomas (SqCC) were found to have stronger glycolytic and glutaminolytic profiles, making it possible to build a valid classification model to discriminate these two subtypes. Chapter 4 reports the NMR metabolomic study of blood plasma from over 100 patients and near 100 healthy controls, the multivariate model built having afforded a classification rate of 87%. The two groups were found to differ significantly in the levels of lactate, pyruvate, acetoacetate, LDL+VLDL lipoproteins and glycoproteins (increased in patients), together with glutamine, histidine, valine, methanol, HDL lipoproteins and two unassigned compounds (decreased in patients). Interestingly, these variations were detected from initial disease stages and the magnitude of some of them depended on the histological type, although not allowing AdC vs. SqCC discrimination. Moreover, it is shown in this chapter that age mismatch between control and cancer groups could not be ruled out as a possible confounding factor, and exploratory external validation afforded a classification rate of 85%. The NMR profiling of urine from lung cancer patients and healthy controls is presented in Chapter 5. Compared to plasma, the classification model built with urinary profiles resulted in a superior classification rate (97%). After careful assessment of possible bias from gender, age and smoking habits, a set of 19 metabolites was proposed to be cancer-related (out of which 3 were unknowns and 6 were partially identified as N-acetylated metabolites). As for plasma, these variations were detected regardless of disease stage and showed some dependency on histological subtype, the AdC vs. SqCC model built showing modest predictive power. In addition, preliminary external validation of the urine-based classification model afforded 100% sensitivity and 90% specificity, which are exciting results in terms of potential for future clinical application. Chapter 6 describes the analysis of urine from a subset of patients by a different profiling technique, namely, Ultra-Performance Liquid Chromatography coupled to Mass Spectrometry (UPLC-MS). Although the identification of discriminant metabolites was very limited, multivariate models showed high classification rate and predictive power, thus reinforcing the value of urine in the context of lung cancer diagnosis. Finally, the main conclusions of this thesis are presented in Chapter 7, highlighting the potential of integrated metabolomics of tissues and biofluids to improve current understanding of lung cancer altered metabolism and to reveal new marker profiles with diagnostic value.
A presente tese reporta a aplicação da metabolómica ao estudo de tecidos e biofluidos humanos (plasma sanguíneo e urina), com o intuito de caracterizar a assinatura metabólica do cancro pulmonar primário. No Capítulo 1, apresenta-se uma breve introdução sobre a epidemiologia e a patogénese deste tipo de cancro, bem como um sumário das principais alterações metabólicas tipicamente associadas ao cancro em geral. Descreve-se ainda a abordagem metabolómica, nomeadamente os métodos analíticos e estatísticos utilizados, assim como o estado da arte da sua aplicação em estudos clínicos do cancro do pulmão. No Capítulo 2, apresentam-se os detalhes experimentais deste trabalho, no que diz respeito ao grupo de indivíduos envolvidos, à colheita e análise das amostras e ao posterior tratamento dos dados. O Capítulo 3 descreve a caracterização metabólica de tecidos do pulmão (de 56 doentes) por espetroscopia de Ressonância Magnética Nuclear (RMN) de alta resolução com rotação no ângulo mágico. Após a otimização cuidada das condições de aquisição e a identificação detalhada dos sinais espetrais (mais de 50 metabolitos identificados), os perfis metabólicos dos tumores e dos tecidos adjacentes não envolvidos (controlos) foram comparados por análise multivariada, tendo sido discriminados com uma exatidão de 97%. Os metabolitos que mais significativamente contribuíram para esta diferenciação foram: glucose e acetato (diminuídos nos tumores), lactato, alanina, glutamato, GSH, taurina, creatina, fosfocolina, glicerofosfocolina, fosfoetanolamina, nucleótidos de uracilo e péptidos (aumentados nos tumores). Algumas destas variações corroboraram alterações típicas do metabolismo do cancro (e.g., glicólise e glutaminólise aumentadas), enquanto outras sugeriram novas pistas sobre a possível relevância de processos como a proteção antioxidante e a degradação proteica. Um outro resultado novo e importante descrito neste capítulo foi a dependência da assinatura metabólica em relação ao tipo histológico do tumor. Enquanto as principais alterações observadas nos adenocarcinomas (AdC) se relacionaram com o metabolismo fosfolipídico e proteico, os carcinomas de células escamosas (SqCC) apresentaram perfis glicolíticos e glutaminolíticos mais pronunciados, sendo possível construir um modelo válido para a discriminação destes subtipos. No Capítulo 4, apresenta-se o estudo metabolómico por RMN de plasma sanguíneo de mais de 100 doentes e quase 100 controlos saudáveis, do qual resultou um modelo multivariado com uma taxa de classificação de 87%. A distinção entre os grupos foi feita essencialmente com base nos níveis de lactato, piruvato, acetoacetato, lipoproteínas LDL+VLDL e glicoproteínas (aumentados nos doentes), juntamente com os níveis de glutamina, histidina, valina, metanol, lipoproteínas HDL e dois compostos não identificados (diminuídos nos doentes). Estas variações foram detetadas desde os estádios iniciais da doença e a magnitude de algumas delas dependeu do tipo histológico, embora não permitindo discriminar AdC de SqCC. Para além disso, mostra-se neste capítulo que o desequilíbrio dos grupos controlo e cancro em termos da idade dos indivíduos poderá ter alguma influência nos resultados, e apresenta-se uma tentativa exploratória de validação externa, que resultou numa taxa de classificação de 85%. O estudo por RMN do perfil metabólico da urina dos doentes com cancro do pulmão e dos controlos é apresentado no Capítulo 5. Comparativamente ao plasma, o modelo construído com os perfis urinários apresentou uma taxa de classificação superior (97%). Após uma avaliação cuidada da possível influência do género, idade e hábitos tabágicos, um conjunto de 19 metabolitos foi proposto como estando relacionado com a doença (incluindo 3 compostos desconhecidos e 6 parcialmente identificados como metabolitos N-acetilados). Tal como no caso do plasma, estas variações foram detetadas em doentes no estádio inicial e mostraram alguma dependência em relação ao tipo histológico, obtendo-se um modelo válido para a discriminação AdC vs. SqCC, ainda que com um poder preditivo modesto. Para além disso, o teste preliminar de validação externa revelou 100% de sensibilidade e 90% de especificidade, o que é um resultado bastante promissor em termos da potencial utilização dos perfis urinários em aplicações clínicas futuras. No Capitulo 6, descreve-se a caracterização dos perfis metabólicos da urina (de um subgrupo de indivíduos) por cromatografia líquida de ultra-eficiência acoplada a espetrometria de massa (UPLC-MS). Embora não avançando muito na identificação estrutural de possíveis marcadores, este estudo reforçou o valor diagnóstico da urina, já que os modelos multivariados resultantes apresentaram taxa de classificação e poder preditivo elevados. Finalmente, no Capítulo 7, apresentam-se as principais conclusões deste trabalho, realçando o contributo da metabolómica integrada de tecidos e biofluidos para a compreensão do metabolismo alterado do cancro do pulmão e para a deteção de novos perfis marcadores com valor diagnóstico.

Vanilla planifolia, orchidée épiphite florifère, est la principale source naturelle de l'arôme de vanille. Largement utilisé dans les produits laitiers, les boissons, les pâtisseries et les parfums, cet arôme est le résultat d'un processus complexe : de huit à neuf mois après la fécondation des fleurs, les gousses matures sont récoltées et traitées pendant environ un an afin de libérer leur bouquet aromatique. Aujourd'hui, plus de la moitié de la production mondiale de vanille provient de Madagascar. Pour faire face à cette concurrence, les producteurs de la Réunion se tournent vers la production de vanille "haut de gamme". L'exploitation des vanilliers les plus intéressants du point de vue aromatique est donc favorisée. Toutefois, les programmes d'amélioration se heurtent au manque de connaissances sur la physiologie de la plante. Il devient alors essentiel de mieux comprendre les mécanismes physiologiques et biochimiques impliqués dans la production aromatique des gousses de V. planifolia. Dans ce travail de thèse, une analyse des métabolites présents dans les gousses vertes et les feuilles de vanille a été effectuée par Résonance Magnétique Nucléaire. Cette technique permet l'évaluation qualitative et quantitative des métabolites primaires (sucres, acides animés et organiques...) et secondaires (composés phénoliques...) présents dans la plante dans diverses conditions physiologiques : au cours du développement de la gousse, lors d'une infection virale, selon les saisons ou encore sur différentes accessions
Vanilla planifolia, a flowering epiphitic orchid, is the major natural source of vanilla flavour. Largely used in dairy products, beverages, bakeries and perfume, vanilla flavour is obtained after a long process: from eight to nine months after flower pollinisation, mature pods are harvested and then prepered during about one year in order to release the characteristic vanilla aroma. Nowadays, more than half vanilla pods world production comes from Madagascar. To face the concurrence, a solution could be develop higher quality pods. Selection of the most aromatic vanilla plant is then preferred. Nevertheless, amelioration program are facing up to a lack of knowledge in vanilla plant physiology. It is now essential to understand more the physiological and biochemical mechanisms implied in the aromatic production of V. planifolia pods. In this thesis, a metabolomic analysis of vanilla green pods and leaves has been performed by nuclear magnetic resonance. This technique has allowed the qualitative and quantitative analysis of primary (sugar, amino and organic acids...) and secondary metabolites (phenolic compounds...) present in vanilla plant according to various physiological conditions: developing pods, viral infection, inter-accession or seasonal variation

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.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1997.
Includes bibliographical references (leaves 119-121).
by Howard Fred Sklar.
M.S.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1999.
Includes bibliographical references (leaves 96-100).
This thesis describes the design and applications of an improved Nuclear Magnetic Resonance (NMR) microscope, which permits MRI to study small sample sizes ( < 2mm) at high resolution (up to 2[mu]m). The effects of molecular diffusion and local variations in the magnetic susceptibility in NMR microscopy are described, which, along with the intrinsic low sensitivity of NMR, are the fundamental limitations to resolution. Molecular diffusion in the presence of a magnetization grating not only broadens the point spread function but also reduces the signal intensity. The significance of these effects depends strongly on the magnetic field gradient strengths and imaging protocols. A NMR microscope for a standard bore 14.lT magnet was developed, it is equipped with a highly efficient. solenoidal RF coil and three orthogonal gradients with strengths of 1260G / cm for Gz , 760G/cm for Gy , and 410G/cm for Gx at 15A. A modified CTI sequence is presented which incorporates strong pulsed gradients, Ernst angle excitation, CP coherent detection and reduced k-space sampling. It is the optimal pulse sequence for acquiring high-resolution ( < 5[mu]m) NMR images (best signal-to-noise ratio per unit time) when the effect of molecular diffusion is significant. It is demonstrated that this new sequence makes it possible to acquire images with a high resolution of 2[mu]m x 2[mu]m x 8[mu]m within a few hours. A wide variety of images have been acquired using the new microscope, and representative images are presented to demonstrate the potential of NMR microscopy as a new tool in developmental biology research. In particular, used in combination with other biological techniques, NMR microscopy can provide a robust, non-invasive, 3D imaging approach to quantifying changes in structure due for instance to radiative exposure, therapy, and natural growth or genetic modifications.
by Xiao-wu Tang.
Ph.D.

The work described in this thesis was initiated in an attempt to overcome the limitations imposed upon NMR spectroscopy by magnetic field inhomogeneity in two specific areas: high resolution spectroscopy in isotropic liquids, and chemical shift resolved NMR imaging in isotropic liquids. In both cases magnetic field inhomogeneity may degrade the resolution of spectra to such an extent that no useful information can be obtained from them. In high resolution NMR spectroscopy it is necessary to be able to extract accurately the parameters present within the spectrum such as chemical shifts, coupling constants and peak areas. In chemical shift resolved imaging experiments the requirements are less stringent; and it is only necessary that the resonances of different chemical species be resolved. However, even the less stringent requirements of NMR imaging are often difficult to meet as the sample volumes required are often several orders of magnitude larger than those required in conventional high resolution NMR spectroscopy. The use of zero-quantum coherence has been investigated as a potential solution to the magnetic field inhomogeneity problem in both of these areas. Zero-quantum coherences are independent of magnetic field inhomogeneity and contain the parameters desired in both cases, though they are displayed in a way which differs from conventional NMR spectra. In this thesis, existing zero-quantum coherence experiments have been evaluated for use with inhomogeneous magnetic fields, and, where necessary, adapted for this purpose. Several completely new experiments have been developed for producing broad-band decoupled zero-quantum coherence spectra and also for presenting coupling constants and chemical shifts in a manner which is as close to conventional NMR spectra as possible, hence facilitating ease of use. Zero-quantum coherence has been evaluated as a tool for identifying unknown compounds and also for identifying the components of complex mixtures by "signature" recognition. Both decoupled and non-decoupled zero-quantum coherence experiments are adapted to provide imaging experiments which allow the separation of the images of different chemical species in inhomogeneous magnetic fields. The two-dimensional J-resolved experiment is also adapted for this purpose.
Science, Faculty of
Chemistry, Department of
Graduate

The work presented in this thesis has involved the development and experimental implementation of a new method incorporating Nuclear Magnetic Resonance (NMR) methodology, and which enables a volume to be accurately defined and non-invasively interrogated within a larger object, by a sequence of radiofrequency (RF) and linear magnetic field gradient pulses. The most important feature of the VOISINER (volume of interest by selective inversion, excitation and refocusing) sequence is its flexibility with respect to the location and size of the region of interest. The spatial coordinates and the size of the volume of interest can be directly selected from conventional NMR images and then converted into the VOISINER sequence by an appropriate setting of the radiofrequency carrier frequencies of the frequency-selective RF pulses and an appropriate scaling of the field gradient strengths used during those RF pulses. As part of the experimental protocol, the VOISINER sequence was actually combined with conventional spin echo imaging in order to facilitate the selection of the region of interest and the optimization of the spatial sensitivity profile of the localization process. The applicability of the VOISINER sequence was then examined under various experimental conditions in order to evaluate the factors that can deteriorate or improve the efficiency of its spatial selectivity and detection sensitivity. Potential extensions of the VOISINER technique for extracting a variety of high-resolution NMR information have been explored and experimentally demonstrated by combining it with conventional NMR methodology. In particular, it was combined with the inversion recovery method to measure on a model system, spatially localized spin-lattice (T₁) relaxation times. With regard to imaging, studies of a model system have been used to evaluate the technical prospects for using the VOISINER sequence as the basis for high-resolution imaging of small regions within a large object. Finally, to demonstrate that the technique is applicable for studies of living systems, it was tested on a human forearm and spatially localized ¹H high-resolution spectra were successfully obtained from muscle tissue and bone marrow.
Science, Faculty of
Chemistry, Department of
Graduate

Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2010.
Page 104 blank. Cataloged from PDF version of thesis.
Includes bibliographical references.
The monitoring of physiological biomarkers is fundamental to the diagnosis and treatment of disease. We describe here the development of molecular sensors which can be read by magnetic resonance (MR) relaxometry. MR is an advantageous bio-sensor readout because it can be determined from opaque samples and through intervening layers of matter. Wash steps can therefore be avoided in in vitro MR assays and non-invasive interrogation achieved for in vivo MR sensing. Functionalized magnetic nanoparticles originally developed as in vivo contrast agents have recently been adapted for use in magnetic relaxometry assays. The first half of this thesis describes a simple particle functionalization strategy and its application to the detection of myocardial infarction ("heart attack") associated biomarkers. The particles were subcutaneously implanted in the form of small discrete sensors and shown to be efficacious in measuring the physiological release of three protein biomarkers. Alternative contrast mechanisms may also be employed by MR readable sensors. The second half of this thesis introduces the novel use of 'smart' polymers which produce analyte-responsive changes in MR relaxivity. We show that MR responsive calcium-crosslinked and pH-swelling hydrogels can be incorporated within discrete sensors.
by Yibo Ling.
Ph.D.

Höchste Magnetfelder haben sich zu einem unverzichtbaren Werkzeug der Festkörperphysik entwickelt. Sie werden insbesondere verwendet, um die elektronischen Eigenschaften von modernen Materialien zu erforschen. Da Magnetfelder oberhalb von 45 Tesla nicht mehr mit statischen (z.B. supraleitenden) Feldern zu erreichen sind, haben sich weltweit verschiedene Labore auf die Erzeugung gepulster Magnetfelder mit angestrebten Maximalwerten von 100 Tesla spezialisiert. In der vorliegenden Arbeit werden Anwendungsmöglichkeiten der kernmagnetischen Resonanz (NMR) in gepulsten Magnetfeldern aufgezeigt. Es ist gelungen, die starke Zeitabhängigkeit der gepulsten Magnetfelder mittels NMR präzise zu vermessen. Die genaue Kenntnis des Magnetfelds nach dem Puls ermöglicht, die Zeitabhängigkeit aus den Daten zu entfernen, sodass auch eine kohärente Signal-Mittelung möglich ist. Davon ausgehend werden erstmalig Messungen der chemischen Verschiebung, der Knight Shift, der Spin-Gitter-Relaxationsrate 1/T1 und der Spin-Spin-Relaxationsrate 1/T2 diskutiert. Schließlich werden die im Zusammenhang mit gepulsten Magnetfeldern erarbeiteten Gleichungen in vereinfachter Form zur genauen Messung und Analyse des freien Induktions-Zerfalls von 19F Kernspins in Calciumfluorid verwendet. Durch Messung des Zerfalls über sechs Größenordnungen wird eine genaue Analyse bezüglich einer neuartigen Theorie ermöglicht, welche den Zerfall basierend auf der Annahme mikroskopischen Chaos\' erklärt. Diese Theorie hat das Potenzial, zu einem tieferen Verständnis von Quantenchaos in makroskopischen Vielteilchensystemen zu führen.

This work aimed to detect cerebral abnormalities in schizophrenia affecting the volume or T₁ relaxation time of specific anatomical structures. Sixty-seven schizophrenics under fifty years of age, recruited from admissions to two teaching hospitals, underwent nuclear magnetic resonance scanning at 0.5 Tesla along with thirty-six matched healthy controls. Twenty coronal and twenty-four transverse contiguous slices were obtained and subsequently viewed blind to group status. Methods of adequate reliability were developed to estimate volumes of the cerebrum, cortex, sulcal fluid, temporal lobes and lateral ventricles and to measure T₁ times in the centrum semiovale and basal ganglia. Volumetric data from forty-eight patients, analysed using multiple regression to control for the influenced of intra-cranialvolume, revealed a significant increase in sulcal fluid and diffuse reduction in cerebral volume compared to thirty-four controls. This was primarily due to reduction in cortical rather than subcortical tissue. Patients also had a decreased right temporal lobe volume. These changes bore no close relationship to clinical variables. Factors that influence T₁ times in normal subjects were identified, through the additional serial scanning of two healthy males, before comparing the patient and control groups. No group differences in either the white matter or basal ganglia T₁ times were found. An animal model was used to assess the effect of neuroleptic drugs on T₁ values over four weeks, and no sustained alteration was seen.

This thesis describes the application of a wide variety of data processing methods, in particular the Maximum Entropy Method (MEM), to data from Nuclear Magnetic Resonance (NMR) experiments. Chapter 1 provides a brief introduction to NMR and to data processing, which is developed in chapter 2. NMR is described in terms of the classical model due to Bloch, and the principles of conventional (Fourier transform) data processing developed. This is followed by a description of less conventional techniques. The MEM is derived on several grounds, and related to both Bayesian reasoning and Shannon information theory. Chapter 3 describes several methods of evaluating the quality of NMR spectra obtained by a variety of data processing techniques; the simple criterion of spectral appearance is shown to be completely unsatisfactory. A Monte Carlo method is described which allows several different techniques to be compared, and the relative advantages of Fourier transformation and the MEM are assessed. Chapter 4 describes in vivo NMR, particularly the application of the MEM to data from Phase Modulated Rotating Frame Imaging (PMRFI) experiments. In this case the conventional data processing is highly unsatisfactory, and MEM processing results in much clearer spectra. Chapter 5 describes the application of a range of techniques to the estimation and removal of splittings from NMR spectra. The various techniques are discussed using simple examples, and then applied to data from the amino acid iso-leucine. The thesis ends with five appendices which contain historical and philosophical notes, detailed calculations pertaining to PMRFI spectra, and a listing of the MEM computer program.

Nuclear magnetic resonance spectroscopy (NMR) studies of the paramagnetic haemoprotein equine cyanometmyoglobin are presented. Many significant NMR assignments in both the proton and carbon-13 spectra of equine cyanometmyoglobin have been obtained. Notably the full proton and carbon-13 assignments for all four haem methyl groups have been obtained, resolving some previous ambiguity surrounding the assignment of the haem 3-methyl group, and full proton assignments for the haem 4-vinyl group, which is unresolved from the diamagnetic envelope in the one dimensional proton spectrum, have been obtained by use of two dimensional proton-proton shift correlation spectroscopy (COSY). Assignments are also presented for the ubiquitous proximal histidine residue, which plays a role in modulating the activity of the iron centre, as well as for certain other physiologically relevant haem pocket nuclei, providing a valuable basis for future studies of the strueture-function relationships not only of equine cyanometmyoglobin, but also of those other related haemoproteins for which it can be used as a model. It has been demonstrated that the COSY technique, which prior to the commencement of this work was believed to be inapplicable to paramagnetic species, since the line broadening and rapid loss of coherence caused by paramagnetic induced relaxation was thought to interfere with COSY peak detection, may indeed be profitably applied to the study of paramagnetic haemoproteins. The usefulness of other spectroscopic techniques, previously rarely used in the study of biological macromolecules, such as two dimensional heteronuclear shift correlation spectroscopy, and both one and two dimensional techniques involving the editing of the natural abundance carbon-13 spectrum according to the number of attached protons, to the study of paramagnetic haemoproteins has also been demonstrated.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 2003.
Includes bibliographical references.
The goal of the work described in this thesis is to develop the methodology and instrumentation for studying neuron physiology and activation in vivo at near cellular resolution. Using biocompatible crosslinked Hemoglobin (xHb) as a contrast agent, we demonstrated partial local oxygen pressure (pO₂) monitoring in vivo with a home-built high resolution microscopy imaging probe. It is one of the most stable microimaging system designed and fully equipped for microscopic fMRI study. This work is an advancement of using MRI to study fundamental neuron science and cell signal pathways in vivo. NMR Microscopy of pancreatic islet of NOD-SCID mice in vitro has shown the feasibility of tracking T-lymphocytes infiltration into islets before the onset of any diabetes symptoms using contrast agents CLIO-Tat. Application of this to in vivo study will not only advance our understanding of the progression IDDM but also help monitor the treatment and prognosis of IDDM patients. Throughout the high resolution imaging studies at high field (14.1 T), a new gradient sequence was developed to suppress the distortion due to the internal fields. This sequence can faithfully measure the displacement propagator in q-space imaging, and provide the proper displacement contrast in k-space imaging. The constant time imaging technique has been used to image a phantom model of a vascular system. It is made up of two glass tubes, filled with solutions of D[sub]y - DTPA and C[sub]uSO₄ respectively and the field mapping showed significant internal field introduced by their susceptibility difference. The new sequence may find applications in clinical Diffusion Tensor Imaging (DTI) and Diffusion Weighted Imaging (DWI).
by Philip Zhe Sun.
Ph.D.

The work described in this thesis is directed to the examination of the hypothesis that ultrasound may be used to perturb molecular motion in the liquid phase. These changes can then be detected by nuclear magnetic resonance (NMR) in spin-lattice and spin-spin relaxation times. The objective being to develop a method capable of reducing the pulsed NMR acquisition times of slowly relaxing nuclei. The thesis describes the theoretical principles underlying both NMR spectroscopy and ultrasonics with particular attention being paid to factors that impinge on testing the above hypothesis. Apparatus has been constructed to enable ultrasound at frequencies between 1 and 10 mega-hertz with a variable power up to 100W/cm-2 to be introduced in the NMR sample. A broadband high frequency generator is used to drive PZT piezo-electric transducer via various transducer to liquid coupling arrangements. A commercial instrument of 20 kilo-hertz has also been employed to test the above hypothesis and also to demonstrate the usefulness of ultrasound in sonochemistry. The latter objective being, detection of radical formation in monomer and polymer ultrasonic degradation. The principle features of the results obtained are: Ultrasonic perturbation of T1 is far smaller for pure liquids than is for mixtures. The effects appear to be greater on protons (1H) than on carbon-13 nuclei (13C) relaxation times. The observed effect of ultrasonics is not due to temperature changes in the sample. As the power applied to the transducer is progressively increased T1 decreases to a minimum and then increases. The T1's of the same nuclei in different functional groups are influenced to different extents by ultrasound. Studies of the 14N resonances from an equimolar mixture of N, N-dimethylformamide and deuterated chloroform with ultrasonic frequencies at 1.115, 6, 6.42 and 10 MHz show that as the frequency is increased the NMR signal to noise ratio decreases to zero at the Larmor frequency of 6.42 MHz and then again rises. This reveals the surprising indication that an effect corresponding to nuclear acoustic saturation in the liquid may be observable. Ultrasonic irradiation of acidified ammonium chloride solution at and around 6.42 MHz appears to cause distinctive changes in the proton-nitrogen J coupling resonance at 89.56 MHz. Ultrasonic irradiation of N, N-dimethylacetamide at 2 KHz using the lowest stable power revealed the onset of coalescence in the proton spectrum. The corresponding effect achieved by direct heating required a temperature rise of approximately 30oC. The effects of low frequency (20 KHz) on relaxation times appear to be nil. Detection of radical formation proved difficult but is still regarded as the principle route for monomer and polymer degradation. The initial hypothesis is considered proven with the results showing significant changes in the mega-hertz region and none at 20 KHz.