Teses / dissertações sobre o tema "ET-MALDI"
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Stauber, Jonathan. "Imagerie MALDI : nouveaux développements et applications cliniques". Lille 1, 2007. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2007/50376-2007-379.pdf.
Texto completo da fonteThe recent innovations in molecular biology were realized with the evolution of the imaging techniques in the field of Genomics, Transcriptomics, and recently in Proteomics with an essential tool, the mass spectrometry. This imaging technique create characteristic protein profiles of the cellular states, and appears today as an undissociable tool for research in biology and medicine. The last developments look to emerge the mass spectrometry to a molecular imaging to identify pathologies, to observe the drugs distributions in tissues, or the diseases diagnosis or prognosis. This unique and recent technology should be developed, improved, and standardized. It's in this point of view the my PhD training named MALDI imaging new developments and clinical applications was defined. The different results obtained during my PhD were permits to create a concept of Specific Imaging Mass Spectrometry, to develop Molecular MALDI imaging of frozen and FFPE tissues with many applications in the research of specific biomarkers in Parkinson disease and ovarian cancer. The evolution of this unique molecular imaging technique should be in the next years a complementary method of others in vivo imaging technique
El, Hamzaoui Basma. "Identification des arthropodes et pathogènes associés par MALDI-TOF MS et étude des relations entre arthropodes et bactéries". Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0696.
Texto completo da fonteThis work focuses on three main parts, a first part presents an epidemiological study of bacteria associated with soft ticks in Algeria, or we identified morphologically and confirmed by molecular biology six species of Argasidae. In addition, looking further we could detect Borrelia hispanica in Ornithodoros occidentalis and Borrelia cf turicatae in Carios Carpensis. On the other hand, in Argas persicus a new genotype of Bartonella spp has been identified as well as a new species of Anaplasmatacea bacteria.A second part evaluates the vectorial capacity of bed bugs to transmit Borrelia recurrentis, the agent of the relapsing fever. For this reason an experimental model of artificial infection of Cimex lectularius by Borrelia recurrentis has been developed, to study the presence of bacteria in feces. In this model, four approaches were used: qPCR, fece’s culture, FDA (Fluorescein Diacetate) and fece’s inoculation to mice. Immunofluorescence was also used to detect the location of the bacteria in the body of the bed bug. We confirmed that bed bugs acquire the bacteria and excrete live microorganisms in the feces. They can be considered as potential vector of Borrelia recurrentis.The third part is an assessment of the capacity of MALDI-TOF MS to identified fleas, bed bugs and associated pathogens. This innovative tool, which has revolutionized medical entomology and has shown its efficiency to identify several species of arthropods, has also been able to distinguish between infected and uninfected fleas and bugs, and even distinguish between fleas and bugs infected by the same species of bacteria
Jaber, Ali. "Matrices MALDI bithiophéniques spécifiques aux alcaloïdes : étude des mécanismes fondamentaux et applications". Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0042/document.
Texto completo da fonteMy thesis work consisted of pursuing the development and application of bithiophenic maldi matrices specific for alkaloids. After optimization of an efficient analysis protocol adapted to the objective of the study, a method for the determination of alkaloids in vegetable extracts by MALDI was developed. This method was validated by studying many alkaloids existing in extracts of different toxic plants. Subsequently, synthesis and evaluation of novel bithiophenic compounds were presented in order to evaluate the factors favoring the interaction with alkaloids. Then, five matrices among the molecules tested and having produced interesting results are chosen and were the subject of a more detailed study. On the basis of the results obtained, the fluorinated derivative PFPT3P proves to be the most effective molecules. It has a better selectivity with respect to alkaloids than the current matrix HCCA and performs better to analyze these metabolites in different complex mixtures such as crude extracts of plants,insects and commercial bioactive solutions (drug and repellent). At the end, the results of the study of the thermodynamic parameters of MT3P matrix are grouped. This will make possible to propose hypotheses explaining the selectivity of the functionalized bithiophene matrices for alkaloids
Fournier, I. "Développements en Imagerie par Spectrométrie de Masse MALDI et Applications aux Problématiques Biologiques". Habilitation à diriger des recherches, Université des Sciences et Technologie de Lille - Lille I, 2005. http://tel.archives-ouvertes.fr/tel-00167305.
Texto completo da fonteCependant, afin d'augmenter encore la potentialité de cette technologie, des développements restent encore à effectuer. Les recherches menées ont donc plus particulièrement portées sur ces développements.
En particulier, la recherche et l'étude de nouvelles matrices plus adaptées à l'analyse directe de tissu en MALDI sont particulièrement importantes. Dans ce contexte, certaines matrices ioniques se sont révélées particulièrement adaptées aux tissus en permettant d'obtenir une plus grande intensité du signal, un plus grand nombre de composés détectés, de bonnes performances en mode négatif, une grande homogénéité de cristallisation, une grande stabilité sous vide et une faible ablation de matériel consécutivement à l'irradiation laser. Dans un autre aspect, le traitement préalable des tissus permet également une amélioration de la qualité spectrale et des performances d'études structurales en mode MS/MS. Se sont révélés particulièrement intéressants les traitements des tissus aux solvants organiques et les digestions enzymatiques et en particulier pour les tissus conservés en blocs de paraffine après fixation.
D'autre part l'étude de la répartition des ARNm au sein des tissus est un développement crucial afin d'obtenir des images de colocalisation transcriptome/protéome. Est proposé dans ce travail un nouveau concept permettant de réaliser ces images, basé sur une analyse indirecte des ARNm, au travers de l'utilisation d'un groupement photoclivable relié à un peptide marqueur de séquence connue qui sera détecté.
Enfin, l'ensemble de ces développements trouve de nombreuses applications dans le domaine de la biologie et notamment dans le cadre de pathologies tel que le cancer de l'ovaire.
Yssouf, Amina. "Identification des arthropodes vecteurs et des micro-organismes associés par MALDI-TOF-MS". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM5031/document.
Texto completo da fonteArthropods are vectors bloodsucking and can ensure the active biological transmission of a pathogen responsible of human or veterinary diseases. The vector control and vectors epidemiological surveillance are essential in the strategy against the vectors-borne diseases. Accurate, reliable and rapid identification of vectors and associated pathogens are essential. Thus, in this project we evaluated the use of MALDI-TOF MS for the arthropods vectors identification as well as for the detection of associated pathogens. This proteomics technology emerged since few years ago and is currently used in routine for bacteria identification in many microbiology laboratories. In the first part of our work, we used the MALDI TOF to identify the tick, mosquito and flea species. For each arthropod, we determined which part allowed obtaining reproducible spectra by MALDI TOF and correct identification by blind test, after reference database creation. The second part consisted to use the MALDI-TOF MS to detect the associated Rickettsia in ticks including Rickettsia conorii and R. slovaca, two human pathogens transmitted by Rhipicephalus sanguineus and respectively Dermacentors marginatus. The spectral variations were obtained between infected and non infected specimens with specific masses related to the tick infection by Rickettsia. The identification technique of not or infected ticks was validated by blind tests. The obtained results allowed concluding that the MALDI-TOF MS could be used in the future to identify the ticks removed from patient, the arthropods vectors and during entomological survey and determine the prevalence of infection of these arthropods
Kernalléguen, Angéline. "Caractérisation et localisation des xénobiotiques dans les cheveux par spectrométrie de masse Maldi". Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0754.
Texto completo da fonteHair analysis is now recognized as a relevant tool in the field of toxicology. It provides a precise history of an individual’s exposure to drugs, whether it is a punctual or repeated consumption.Matrix-Assisted Laser Desorption/Ionization (MALDI) has many advantages over conventional techniques: the amount of hair needed is reduced, the sample preparation is simplified and the images are acquired with high spatial resolution (~ 100 μm).MALDI (MALDI-MSn) imaging allowed us to characterize and map the evolution of drugs amounts along the hair with very spatial resolution avoiding long and complex pre-sample preparation.MALDI coupled to Microaarays for Mass Spectrometry (MAMS) allowed us to develop a method for semi-quantitation of cocaine, benzoylecgonine, ecgonine methyl ester and cocaethylene using 1 mg of hair and 2 hours of extraction; the results are well correlated with a validated quantification method. This method is relevant when urgent results are required.In total, the development of these two applications demonstrates the relevance of MALDI mass spectrometry in the toxicological analysis of hair. The prospects are to improve these protocols in order to transpose them routinely and to develop large screening methods by MALDI mass spectrometry
Le, Gac Séverine. "Développement de systèmes microfluidiques pour l'analyse protéomique par ESI-SM et MALDI-SM". Lille 1, 2004. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2004/50376-2004-185.pdf.
Texto completo da fonteAu cours de ce travail, différents types de phases monolithiques ont été mis au point et étudiés, tout d'abord dans un support capillaire, puis dans des microcanaux, pour des applications séparatives principalement mais aussi de digestion de protéines. Les premières présentent une fonctionnalité hydrophobe de phase inverse et les deuxièmes, plus poreuses, servent de support pour l'ancrage covalent de l'enzyme de digestion, la trypsine. Les résultats obtenus pour les différentes phases sont à la hauteur de ceux observés sur les supports conventionnels et la possibilité de réaliser des colonnes très longues conduit à des résultats excellents. L'interface avec la spectrométrie de masse est intégrée sur le microsystème afin d'en optimiser le couplage. Ce module s'inspire, par sa géométrie et son fonctionnement, d'une plume de calligraphie. Le liquide, en sortie de microsystème, s'écoule dans la fente capillaire de la plume et est éjecté sous forme de nébulisat dans le spectromètre de masse. Trois générations de plumes, en résine photolithographiable, la SU-8 ou en silicium polycristallin, ont été développées et testés. Leurs performances sont excellentes et surpassent même, pour les prototypes les plus aboutis, celles de sources standard. L'intégration de ces différents modules a été abordée avec la fabrication et le début des tests de microsystèmes intégrés, en résine SU-8, comportant des microcanaux où, sont préparées les phases monolithiques et une interface de sortie de type plume
GILLET, SYLVIE. "Application de la maldi-ms a l'enzymologie moleculaire et a la chimie des proteines". Paris 6, 1996. http://www.theses.fr/1996PA066571.
Texto completo da fonteMatheron, Lucrèce. "Peptides vecteurs et protéomique intracellulaire : détection de phosphorylations par spectrométrie de masse MALDI-TOF". Paris 6, 2011. http://www.theses.fr/2011PA066526.
Texto completo da fontePetkovski, Elizabet. "Polymorphismes ponctuels de séquence et identification génétique : Etude par spectrométrie de masse MALDI-TOF". Université Louis Pasteur (Strasbourg) (1971-2008), 2006. https://publication-theses.unistra.fr/public/theses_doctorat/2006/PETKOVSKI_Elizabet_2006.pdf.
Texto completo da fonteHuman genome polymorphism investigation allows accurate individual identification and genetic relationship establishment. The study of single nucleotide polymorphisms (SNPs) requires short DNA fragments and therefore has a particular advantage over classical markers in the analysis of degraded samples. This and the capacity of yielding high discriminatory powers confer a great value to autosomal SNP markers in the fields of forensics or molecular anthropology. In the present study 50 autosomal SNPs and a sex determining sequence difference between the amelogenin gene gonosomal copies were selected. The characterization of this set of markers represents an innovative work as it allows generating strong discriminatory information and is restricted to non-coding DNA regions, in harmony with the in force French legislation. Our approach to SNP typing is a multiplex PCR based amplification followed by simultaneous detection of primer extension products by MALDI-TOF mass spectrometry. The study of these markers in a French representative population allowed their allelic distribution investigation, their validation as tools for genetic identification and filiation and the development of a direct, sensitive, rapid and multiplexed analysis method yielding reproducible results. The analysis of the selected binary markers represents a complementary means of great help in cases where microsatellite investigation fails due to extensive DNA degradation rather then lack of DNA template. Their specific advantage relies in the identification of discrete samples, such as highly degraded tissues commonly encountered on crime scenes or in mass-disasters. The establishment of a routine protocol will lead to the implementation of the method based on SNP typing in genetic identification laboratories
Petkovski, Elizabet Ludes Bertrand. "Polymorphismes ponctuels de séquence et identification génétique étude par spectrométrie de masse MALDI-TOF /". Strasbourg : Université Louis Pasteur, 2006. http://eprints-scd-ulp.u-strasbg.fr:8080/496/01/Petkovski-2006-These-SNP_et_identification_genetique.pdf.
Texto completo da fonteRaujol, Julie. "Complémentarité du TOF-SIMS et du MALDI-TOF pour l'étude de l'hypoxie dans un modèle in vitro et in vivo". Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM5506.
Texto completo da fonteTissue or cells oxygenation results from a balance between oxygen availability and consumption. This availability is determined by the amount of oxygen carried by the blood irrigating the tissue and its diffusion capacity through the cell membranes. The interruption of blood flow or variations in the oxygen partial pressure are responsible for a reduction of oxygen intake that induces an adaptive response.The aim of my work is to characterize the hypoxia from cellular to tissue-level via the complementarity of two mass spectrometry imaging (MSI) methods: the Secondary Ion Mass Spectrometry (SIMS) and Matrix-Assisted Laser Desorption and Ionization (MALDI). MSI has the potential to provide detection, identification and distribution of a variety of different endogenous and exogenous molecular species directly from the tissue without labelling. Here we combine them to characterize hypoxia in vitro on a 3D cell culture system (spheroid) and in vivo using ischemic rat model.We have shown via TOF-SIMS imaging that reduced availability of oxygen to the center of spheroids induces profound metabolic changes. MALDI-TOF imaging helped to visualize the pharmacokinetics of different treatments in treated spheroids.Concerning the ischemic stroke, MSI provides a molecular signature of hypoxia in tissue, which could bring new insights into the pathological changes induced by the tissue injury.The complementarity of these two imaging techniques allows real synergy for the study of hypoxia in different models
Ait-Belkacem, Rima. "Caractérisation du glioblastome multiforme et suivi de ses chimiothérapies par imagerie MALDI couplée à l'approche top-down". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM5503.
Texto completo da fonteGlioblastoma is the most aggressive of the gliomas, a collection of tumors arising from glia or their precursors within the central nervous system. The current standard of care, comprised of surgical resection followed by radiation and the chemotherapeutic agent temozolomide, only provides patients with a 12-14 months survival period post-diagnosis. The glioblastoma is characterized by a heterogeneous population of cells that are highly infiltrative, angiogenic and resistant to chemotherapy. In order to optimize the therapy effect, a pharmacokinetic monitoring and a better understanding and characterization of tumor biology are needed. For this purpose, matrix assisted laser desorption/ionization imaging mass spectrometry imaging mass spectrometry (MALDI IMS) technology was applied to identify diagnostic, prognostic and predictive markers of therapy response; and to understand/follow the pharmacokinetic of chemotherapies. The top-down in-source decay strategy was used for protein identification directly on tissue. This strategy allowed tubulin protein isoforms distinction and identification, which is one of the main targets in cancer therapy. MALDI imaging coupled to ISD identified tumorigenesis proteins within tumor structures. Bevacizumab and temozolmide distribution was followed within brain tissue sections. For the first time a monoclonal antibody was deciphered on tissue. Finally, markers that predict therapy response were demonstrated by a comparison between protein expression profiles from tumors with and without chemotherapy treatment. These results highlight the interest of MALDI imaging for chemotherapy improvement and open the way for its use in the clinics
Belghazi, Maya. "Etude de modifications covalentes de protéines par spectrométrie de masse Maldi-Tof et Esi-Tof". Palaiseau, Ecole polytechnique, 2001. http://www.theses.fr/2001EPXX0030.
Texto completo da fonteGut, Yoann. "Imagerie par spectrométrie de masse MALDI et outils chimiométriques pour la cartographie de formes pharmaceutiques solides". Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2012.
Texto completo da fonteEuropean Medicines Agency (EMA) recommendations stipulate that pharmaceutical companies have to continually improve manufacturing efficiency to ensure drug product quality. The commonly used analytical tools provide information about drug substance quality and dosage or the drug release profile by dissolving the whole tablet. However these analytical tools are not able to highlight the distribution of chemical compounds contained in the tablet. This is why chemical imaging such as MALDI MSI are used to extract the spatial and spectral information from pharmaceutical solid dosage forms. This hyperspectral imaging technique needs complex sample preparation and generates huge dataset. These two features, as well as the lack of optimized mass spectrometers to study tablets, make difficult the implementation of the MALDI MSI in industrial laboratories. During this thesis, the sample preparation protocol has been improved, the mass spectrometer has been optimized to analyze tablets and chemometrics tools has been developed in order to implement MALDI MSI within Technologie Servier company
Diologent, Laurent. "Développement et caractérisation de techniques pour l’amélioration de la sensibilité et de la résolution spatiale des sources MALDI : désolvatation laser et masques". Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10041/document.
Texto completo da fonteMALDI Mass Spectrometry is an essential tool for biomolecules analysis and is largely employed in various applications. Albeit performances of this ion source are well known, there are still clear limitations in terms of sensitivity and spatial resolution for applications such as MALDI MS Imaging. Indeed, ion production yields are very low in MALDI and, moreover drop when spatial resolution is increased (decrease of irradiated area). Thus, objectives of this work were to develop and study two systems for improving sensitivity. First part of this work was dedicated to setup a system allowing desolvation of material clusters formed in the MALDI process by using a second laser to intercept the expanding plume. By using a pulsed laser emitting at 1064 nm, it was possible to demonstrate an increase of signal intensity by 2 to 3 folds. In a second part, Silicon mask systems allowing reduction of irradiated area (without involving any focusing of the laser beam) was developed. Studies of various geometries of the mask showed their efficiency to reduce irradiated area by cutting part of the laser beam while maintaining signal intensity. Moreover, for certain geometries it was demonstrated that masks could lead to an increase in sensitivity and spectral resolution
Diologent, Laurent. "Développement et caractérisation de techniques pour l’amélioration de la sensibilité et de la résolution spatiale des sources MALDI : désolvatation laser et masques". Electronic Thesis or Diss., Lille 1, 2013. http://www.theses.fr/2013LIL10041.
Texto completo da fonteMALDI Mass Spectrometry is an essential tool for biomolecules analysis and is largely employed in various applications. Albeit performances of this ion source are well known, there are still clear limitations in terms of sensitivity and spatial resolution for applications such as MALDI MS Imaging. Indeed, ion production yields are very low in MALDI and, moreover drop when spatial resolution is increased (decrease of irradiated area). Thus, objectives of this work were to develop and study two systems for improving sensitivity. First part of this work was dedicated to setup a system allowing desolvation of material clusters formed in the MALDI process by using a second laser to intercept the expanding plume. By using a pulsed laser emitting at 1064 nm, it was possible to demonstrate an increase of signal intensity by 2 to 3 folds. In a second part, Silicon mask systems allowing reduction of irradiated area (without involving any focusing of the laser beam) was developed. Studies of various geometries of the mask showed their efficiency to reduce irradiated area by cutting part of the laser beam while maintaining signal intensity. Moreover, for certain geometries it was demonstrated that masks could lead to an increase in sensitivity and spectral resolution
Sachon, Emmanuelle. "Etude de l'interaction entre le récepteur NK-1 et la substance P, par photomarquage et spectrométrie de masse maldi-tof". Paris 6, 2003. http://www.theses.fr/2003PA066298.
Texto completo da fonteNaban-Maillet, Jessie. "Energie interne et dissociations d' espèces moléculaires monochargées et de leurs adduits produits sous AP-MALDI : application à la détection d'agents chimiques". Paris 6, 2006. http://www.theses.fr/2006PA066302.
Texto completo da fonteLo, Cheikh Ibrahima. "Répertoire des bactéries identifiées par Maldi-Tof en Afrique de l'Ouest". Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM5051/document.
Texto completo da fonteThe Africa bacteria repertory is unfamiliar because the available tools in this region are not allowed its best knowledge. In fact, bacteria are most often identified using culture techniques on simple media and biochemical tests which enable the identification of some common characters. These methods do not facilitate an exhaustive knowledge of the bacterial repertory; consequently they have recently been revolutionized by the systematic use of MALDI-TOF mass spectrometry (MS).In our thesis we used two mass spectrometers, respectively, MALDI-TOF Vitek MS currently installed at Dakar (Senegal) and MALDI-TOF Microflex LT installed in Marseille (France). In addition we have also confirmed that MALDI-TOF is a powerful tool for identifying bacterial species rarely involved in human infectious diseases. Thus in adopting the MALDI-TOF as a first-line tool in bacterial identification before Gram staining or other techniques of phenotypic identifications based on chemical characteristics, we discovered seven new species of bacteria isolated for first time in humans. Microbial identification using MALDI-TOF MS is currently feasible in Africa. Its performance and effectiveness in routine diagnosis of clinical microbiology laboratories have been proven. It is necessary either to increase the installation of MALDI-TOF, or establishing a network around a shared MALDI-TOF platform between several structures located in the same area, especially in the underdeveloped countries of Africa amortization of investment costs of the device, because it allowed reducing the time of reporting results and indirectly facilitating better care for patients
Dione, Niokhor. "Exploration du microbiote digestif : stratégies de culture des bactéries anaérobies et de culture difficile". Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0614.
Texto completo da fonteThe human gut microbiota is known to contain around 1012 to 1014 bacteria per gram of feces, with the majority being anaerobic. The latters were first discovered in 1865 by Louis Pasteur while working on fermentation. Anaerobic bacteria are known to play an important role in health and diseases and thus have taken a lot of attention in the medical field, especially in infectiousdiseases and metabolism. These bacteria are known for its sophisticated culture system because its growth requires little to no oxygen. Nevertheless, few is known about these type of microorganisms but with the advancement of molecular biology and sequencing techniques, its study became wider. Culturomics, is a recently developed culture-based approach that relies on optimizing culture conditions for bacterial growth and its identification by MALDI-TOF MS and 16S rRNA sequencing. The present work aims to create and optimized culture condition for anaerobic bacteria along with testing its anaerobic activities. Also, we aim to demonstrate the efficiency of Culturomics and MALDI-TOF in culturing, identifying and describing anaerobic bacteria in clinical microbiology and in the human gut. This approach allowed us to isolate 19 new anaerobic species out of which 9 has been described in this work.Keywords: Human gut microbiota, culture of anaerobic bacteria, culturomics, MALDI-TOF
Piednoël, Hélène. "Recherche de marqueurs biologiques de la dystrophie musculaire de Duchenne par spectrométrie de masse et imagerie MALDI-TOF". Evry-Val d'Essonne, 2005. http://www.theses.fr/2005EVRY0005.
Texto completo da fonteThe aim of this work is the study of Duchenne muscular dystrophy (DMD) markers by MALDI-TOF mass spectrometry (MS and MS/MS). After a description of experimental and of the study issue of this work, results relative to this study, linked to a muscle weakness and associated to a defect of the lipid metabolism. In the same way as over-expression of two proteins implicated, either in muscular degradation mechanisms, or in calcic homeostasis. The study of the fatty acids composition of glycerophosphatidylcholines by MALDI-TOF Mass Spectrometry MS and MS/MS enabled us to characterize a change of the lipid composition of dystrophic cells at the time of the differentiation. This modification has been used as a marker to identify with profiling and imaging MALDI-TOF-MS regenerating areas in sections of a mdx mouse leg muscle. It is the first time that such a slight change in fatty acids composition is observed directly on tissue slices by Mass Spectrometry. This approach can be usefull in monitoring the treatment of the DMD
Niare, Sirama. "Identification du repas sanguin des moustiques par MALDI-TOF MS". Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0575/document.
Texto completo da fonteMALDI-TOF MS (Matrix Assisted, Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry) is a proteomic technique that routinely used for microorganisms identification in clinical microbiology laboratory. Recently, the MALDI-TOF MS was successfully used as a innovative tool for arthropod identification. Thus, in this work we evaluated the MALDI-TOF MS to identify the blood meal sources from engorged mosquitoes. In the first part of our work, a bibliographical review was carried out on the different methods (serological, molecular biology) known in the trophic preference determination of hematophagous arthropods. The second part was optimization of the MALDI-TOF MS for identifying the origin of the blood meal of mosquitoes. For optimization, the Anopheles gambiae Giles and Aedes albopictus were artificially fed on several vertebrate hosts blood using the Hemotek device for two hours under standard conditions. Our results showed intra-species reproducibility and inter-species specificity of MS spectra from mosquitoes engorged on the same or different vertebrate hosts. The MS spectra querying against the database reveal a correct identification of the the blood meal origin from the specimens collected less than 24 hours post-feeding. For field samples, MALDI-TOF MS allowed to detect the mosquitoes blood meal fed on wide variety of domestic hosts. Consequently the MALDI-TOF MS technique would be an effective tool for epidemiological surveys of vector-borne diseases and the identification of the trophic preference of mosquito freshly engorged
Miralles, Guillaume. "Conception et synthèse de nouveaux outils chimiques pour l'étude des phosphoprotéines et la caractérisation de la liaison d'un ligand à son récepteur par spectrométrie de masse MALDI-TOF". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20196/document.
Texto completo da fonteSince the advent of soft ionization techniques such as MALDI or ESI, mass spectrometry has become an indispensable tool for the study of biomolecules, and particularly proteins. The specific ionization mechanism of MALDI leads to a spectral discrimination phenomenon generally regarded as a restriction. The α-cyano 4-hydroxy cinnamic acid (HCCA) pattern grafting on a peptide can take advantage by introducing a spectral discrimination in favor of the labeled compound. Two applications have been developed during this thesis, based on HCCA tagging.A limitation of phosphoproteomic studies is the low ionization of phosphorylated peptides. Many purification methods have been reported to circumvent this problem. We studied an alternative approach which consists in specifically grafting a HCCA moiety on a phosphorylated position in order to amplify the signal of interest peptide.At the same time, we have developed a methodology for the study of ligand peptidic binding to its receptor which does not require radioactivity. The covalent HCCA tagged ligand has allowed us to detect and quantify it, in a binding displacement assay. More particularly, this methodology allowed us to determine the affinity of a reference ligand for the V1A vasopressin receptor
Mauger, Florence. "Développement de méthodes d'analyse de l'ADN par clivage d'une chimère ARN/ADN et par spectrométrie de masse MALDI-TOF". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00833267.
Texto completo da fonteMoussaoui, Louardi. "Applications de la spectrométrie de masse type MALDI-TOF à la bactériologie et à la distinction de variants génétiques". Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00872251.
Texto completo da fonteArafah, Karim. "Étude lipidomique et développements en imagerie MALDI des lipides : application à la régénération du système nerveux central d'Hirudo medicinalis". Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10152/document.
Texto completo da fonteLipids are metabolites which can be declined in many classes. Most of them are known to figure as structural molecules in the cell membrane but a significant key role is also played as cellular messenger when interacting with specific membrane receptors. The leech Hirudo medicinalis which is a model for the neurosciences is able to regenerate its central nervous system (CNS) after a lesion in opposition with the CNS of vertebrate. In this way, we showed by Tof-SIMS imaging changes in the lipidome of harmed leech brain directly on tissue. In particular lipids such as fatty acids and triglycerides have been characterized during injuries of the leech CNS. These lipids were expressed in specific areas of damaged neurons. We also characterized endocannabinoids in crude lipid extracts of harmed leech brain by MALDI-Tof Tof mass spectrometry. The identified endocannabinoids anandamide (AEA) and 2-arachidonyl glycerol (2AG) are lipids which act as cellular messenger. During the injury of the leech brain, an increase in the 2AG concentration in the brain were demonstrated while AEA was decreasing. As a consequence, a modulation in the chemotactic effect on microglial cells was observed in the harmed connective. 2AG and AEA have also been demonstrated to regulate the NO release in activated microglia under neurotoxic rate. A new approach in developpemental research in lipidomic using MALDI imaging mass spectrometry allowed us to validate for the first time the use of specific histochemical dies for lipids as a way to detect and characterize lipids directly on rat brain tissue. This new approach of studiying lipids using dies named DALDI Tof-Tof (Dye-Assisted Laser Desorption Ionisation Time-of-fligh)has been successfully applied to the ovarian cancer where different patterns in the lipid content were detected on tissue slices between benign and malignant areas. This work highlighted in one hand the roles played by cannabinoids on the microglia chemotaxis and the regulation of NO secretion at the lesion site and in the second hand, the expression of specific lipids on neurons close to the lesion site during the regeneration process of the damaged leech CNS. Moreover, by using histological dies specific the the lipid staining as matrices, we showed that MALDI imaging of lipids allowed to detect lipids which could be potentially biomarkers for ovarian cancer. A cross-talk with scientist and medical fields can emerged since using both the same way to detect lipids on tissue for diagnosis purposes
Ohara, Keiichiro. "Interactions non covalentes de dérivés guanidylés avec l'ADN : synthèse, évaluation biologique et analyse par spectrométrie de masse MALDI-TOF". Montpellier 2, 2008. http://www.theses.fr/2008MON20154.
Texto completo da fonteHugon, Perrine. "Etablissement du répertoire humain des procaryotes et diversité du microbiote digestif par approches variées". Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM5040.
Texto completo da fonteBacterial taxonomy has undergone tremendous changes over time, with little historical consensus regarding specific descriptions of prokaryotes. The prokaryotes have been estimated about 107 species, and the current classification contained more than 12,900 species. This highlights the absence of an exhaustive and specific database listing all prokaryotes associated with humans. We found than the human prokaryotic repertoire contained 2,156 species, divided among 12 different phyla.The second aim of our work was to characterize the human gut microbiota using 5 different techniques, including morphologic and molecular approaches (flow cytometry, gram staining, electron microscopy, qPCR and pyrosequencing). We analyzed 16 stools samples of patient and we copared the rate of gram-positive and gram-negative prokaryotes obtained with each technique. We found than by pyrosequencing only a half of gram-negative prokaryotes was detected.Our third goal was to demonstrate that bacterial culture was not inferior to pyrosequencing to describe the gut diversity. Culturomics concept created during the pioneer study has revolutionized the approach of the microbiota exploration. Since 4 years, we have performed the analyze of 685 different samples and identified more than 500,000 colonies using the MALDI-TOF mass spectrometry. We have increased by 77.5% the number of species isolated in the gut. Each new species will be described following our new concept named "taxonogenomics", including phenotypic data and genome sequencing
Cassagne, Carole. "Identifications de champignons d'intérêt médical en mycologie et parasitologie par spectrométrie de masse de type MALDI-TOF : applications au diagnostic des infections fongiques". Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM5064.
Texto completo da fonteDuring the last decade, MALDI-TOF MS has revolutionized microbiology by enabling the accurate identification of bacteria and yeast in only few minutes1. At the beginning of this work in 2010, MALDI-TOF MS was not yet optimized for mold identification. To meet this need, we established an identification protocol to generate interpretable mold spectra. The structure of the reference database was developed taking intoaccount the heterogeneity of molds in culture. Finally, a comprehensive reference database,including references for the majority of molds encountered in human pathology, was created in collaboration with the BCCM/IHEM. Identification performance of this database was tested and validated at both a local scale and an international scale . We also determined the best-adapted pre-treatment protocol to identify yeasts in a routine setting. The protocol was tested on a panel of 6192 yeast isolates recovered from clinical samples submitted to our laboratory over the course of one year. Using our fungal identification system, we were able to identify morphologically similar species and highlight the underestimation of fungal pathogen diversity. The development of our MALDI-TOF MS-based fungal identification system presents numerous opportunities in the field of mycological, from both an epidemiological and clinical point of view. In subsequent studies, defining the clinical meaning of emerging species identified via MALDI-TOF MS will profoundly modify our perspective of fungal diseases
LATOURTE, LAURENCE. "Processus de desorption/ionisation en maldi et esi : application de la spectrometrie de masse a l'etude de polymeres synthetiques industriels". Paris 6, 1998. http://www.theses.fr/1998PA066200.
Texto completo da fonteTahir, Djamel. "Moustiques et dirofilariose : mise au point et utilisation d'outils innovants pour la détection et la surveillance". Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0406/document.
Texto completo da fonteIn this work, we are interested in studying dirofilarial infections in dogs and vectors “Mosquitoes” especially detection, monitoring and prophylaxis. The first objective is to develop a real-time duplex PCR targeting the COI gene capable of simultaneously detecting and differentiating D. immitis and D. repens. Subsequently, we applied this tool to a canine dirofilariosis surveillance process in different endemic areas of Mediterranean basin (Corsica and Algeria). We have thus detected by this molecular tool for the first time in France, D. immitis and D. repens in Aedes albopictus mosquitoes. We reported, also, the presence of D. immitis in dogs from northern Algeria.The second aim was to assess whether the MALDI-TOF MS can detect changes in the protein profiles of Aedes aegypti infected experimentaly with filarial nematodes (D. immitis, Brugia malayi and B. pahangi). Obtained results showed the potential of MALDI-TOF MS as a reliable tool for differentiating non-infected and filariae-infected Ae. aegypti mosquitoes with a best correct classification rate obtained from the thorax-head part with 94.1 and 86.6, 71.4 and 68.7% for non-infected and D. immitis, B. malayi and B. pahangi infected mosquitoes respectively.The third aim of this work has focused on the evaluation of the anti-feeding and insecticidal efficacy of an ectoparasiticide (Vectra® 3D) containing three active ingredients: dinotefurane, pyriproxyfen and permethrin (DPP) against Ae. albopictus. Results demonstrated that the DPP combination has significant anti-feeding and insecticidal efficacy against Ae. albopictus for at least 4 weeks
Rossato, Maxime. "La dilution isotopique en spectrométrie de masse MALDI-ToF pour la mesure d’interactions entre récepteurs couplés aux protéines G et ligands peptidiques". Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTS007/document.
Texto completo da fonteThe SID methodology, for Stable Isotope Dilution, is a widely applied methodology for peptides and proteins analysis in mass spectrometry, usually associated with atmospheric pressure ionisation techniques. This thesis is consequently devoted to the application of SID methodology in matrix assisted laser desorption/ionisation (MALDI) mass spectrometry to quantify receptor/ligand interaction in pharmacology. Indeed, a great number of pathologies involve membrane receptors like G protein coupled receptors (GPCR) in interaction with several ligands, frequently peptides. Particularly, the V1A receptor, is related to vasoconstriction activity of the peptide hormone AVP (arginine vasopressine) and contraction of muscular cells as well as many social behaviors. This receptor was chosen as model, requiring the chemical labelling of the ligand Homo-HO-LVA (Hydroxy Linear Vasopressin Antagonist), selected for its high affinity towards the V1A receptor in order to introduce the entity on which relies the quantification in SID/MALDI. This methodology is applied through the covalent binding of HCCA (4-hydroxy-α-cyanocinnamic acid) matrix, usually encountered in peptide analysis, to obtain the modified peptide (JMV4854) through N-terminal acylation. The objective is to take advantage of the use of both HCCA tagging and HCCE (4-hydroxy-α-cinnamic methyl ester) matrix for the specific and sensitive detection of compounds down to picomolar concentrations. Importantly, quantification with SID requires a calibration protocol and a statistical validation before pharmacological assays. This consists in the measurement of JMV4854 affinity towards V1A-R through thermodynamic experiments in order to quantify the dissociation constant (Kd) and determine afterwards constants for untagged molecules by competitive binding assays. Furthermore, a second receptor model, CCKB-R (cholecystokinine B receptor), was then studied to validate the quantification methodology. Facing the renewed interest in pharmaceutic industry of kinetic experiments for dissociation constant measurement, it would be interesting to apply this new methodology to drug discovery, representing a relevant alternative to current “gold-standard” methodologies such as radioactivity and fluorescence. A second field of research has been initiated with a covalent labelling designed to enhance peptide fragmentation for electrospray-based (ESI-MS/MS) tandem mass spectrometry measurements. Preliminary studies with the synthesis of pre-formed ions like N-terminal substitution with pyridinium entities gave very promising results opening the way of other quantification strategies
Dieme, Constentin. "Etude des relations entre arthropodes et rickettsia felis". Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM5042/document.
Texto completo da fonteVector control is one of the most important aspects of medical entomology and requires accurate identification of vectors. Within the past decade, the MALDI-TOF MS technique has proven its potential as a fast and effective tool for identification of adult blood-sucking arthropods. From then on we were interested in the development of an identification protocol of aquatic stages of mosquitoes by MALDI-TOF MS. On the other hand, the detection of a pathogen in an arthropod does not necessarily mean its ability to transmit. Incrimination of an arthropod as vector follows certain rules ranging from suspicion to demonstrate its vector competence in the laboratory. To better understand the epidemiology of R. felis we first participated in an investigation conducted in Reunion, testing fleas, the only biological vectors known to date. We demonstrated the potential role of the mosquito particularly Anopheles gambiae, in the transmission of R. felis. Finally, we used the MALDI-TOF MS for the determination of the Anopheles gambiae infection status to R. felis. We also offer a probable transmission cycle of R. felis to man including psocids and mosquitoes
Million, Matthieu. "Caractérisation des altérations du microbiote digestif associées à l'obésité et rôle de la manipulation du microbiote digestif dans l'obésité". Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM5024.
Texto completo da fonteThe revolution of large scale molecular sequencing methods allowed the identification of specific alterations in the gut microbiota associated with obesity such as a decreased Bacteroidetes / Firmicutes ratio in obese individuals. Since then, many studies have described different alterations associated with obesity, including an increase in members of the Lactobacillus genus, but results are often controversial. To clarify whether the genus Lactobacillus was associated with obesity, we conducted two case-control studies (the second being the follow-up of the first study with a total of 263 individuals) allowing us to understand that gut microbiota alterations are more reproducible at the species level. We found a greater concentration of Lactobacillus reuteri in the gut microbiota of obese while concentrations of Bifidobacterium animalis, Methanobrevibacter smithii and Escherichia coli were reduced. We were able to establish a dose-dependent relationship between the concentration of Lactobacillus reuteri and body mass index. In addition, we performed a meta-analysis on the results of published studies and we found an association between the Bifidobacterium (6 studies, 348 individuals) and Methanobrevibacter (3 studies, 195 individuals) with absence of obesity. (…)
Quero, Laura. "Développement de la spectrométrie de masse MALDI -TOF pour l'identification des champignons filamenteux d'intérêt alimentaire et étude de leur résistance aux molécules biocides". Thesis, Brest, 2018. http://www.theses.fr/2018BRES0109/document.
Texto completo da fonteSpoilage fungi represent a major cause of food and economic losses and certain species, which may produce mycotoxins, may also pose a threat to human and animal health. Thus, food safety and quality management relies notably on a good knowledge of the involved species. This knowledge is notably based on their fast and reliable identification and on the study of abiotic factors affecting their growth such as food preservatives, which are commonly used in the food industry. In this context, the objectives of this PhD. thesis were to develop MALDI-TOF mass spectrometry for mold identification and to evaluate its potential for species complex differentiation and strain typing, and finally, to evaluate the use of laser nephelometry to monitor fungal growth in the presence of food preservatives.First, a robust database was developed with 6500 spectra corresponding to 136 spoilage fungi. Then, MALDI-TOF MS was successfully applied to differentiate 23 species of Aspergillus section Flavi and Penicillium roqueforti isolates belonging to 3 genetically distinct populations.Finally, in 14 fungal species, laser nephelometry allowed a high-throughput monitoring of their growth after exposition to 3 different food preservatives and the determination of their associated minimal inhibitory concentrations.Overall, the obtained results demonstrate the usefulness of alternative techniques for identification and characterization of food spoilage fungi
Jemmali, Zaïneb. "Développements méthodologiques en TLC/MALDITOF MS et GC/MS pour l’analyse des composés terpénoïdes présents dans les résines végétales". Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2061/document.
Texto completo da fonteResins are hydrocarbon secretions of many plants and well known for their protective benefits. They have been used as raw materials for a wide range of applications (pharmaceutic, cosmetic and artistic). Plant resins are complex mixtures of organic substances mainly terpenoid compounds which constitute the most abundant and structurally diverse group of plant secondary metabolites. The chemical characterization of this material results in long and difficult separation due to the wide range of polarity and volatility of its constituents. The aim of this work was to develop new analytical approaches to improve the identification of resins certifying their origin and ensuring the quality control. For that purpose two analytical methods were selected: TLC and GC approaches hyphenated to mass spectrometry. TLC-1D and TLC-2D allow a rapid screening and first visual differences of resins. The innovating TLC coupling to MALDI-TOF-MS gives a clear identification of major markers (triterpenic acids). In order to have complementary information about the composition of resins, a gas chromatography-mass spectrometry (GC-MS) method was developed to analyze volatile to non-volatile compounds. The various stages of optimization were based on experimental design and statistical (PCA and HAC) approaches. For closely related resins, a quantitative approach was investigated based on a complete validation for major markers. This work allows the development of two complementary techniques that give a powerful approach for fast and reliable differentiation of various resins even the closest ones
Lemaire, Rémi. "Nouveaux développements pour l'imagerie par spectrométrie de masse MALDI : applications aux problèmes biologiques et à la recherche de biomarqueurs dans le cancer de l'ovaire". Paris 6, 2006. http://www.theses.fr/2006PA066288.
Texto completo da fonteGranzotto, Clara. "Methodological developments based on mass spectrometry for the analysis of glycoproteins and polysaccharides of plant gums : an application to cultural heritage samples". Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10221/document.
Texto completo da fonteThe analysis of Cultural Heritage samples is critical for the understanding of the arstists' technique, the conservation and restoration of artworks. These objects under investigation are rare and precious and the amount of sample available for the analysis is usually very low, thus implying the development and the optimization of adapted analytical methodologies. The objective of this PhD was to develop new analytical methods to study glycoproteins and polysaccharides from plant gums in Cultural Heritage samples.These macromolecules have been separated by size exclusion chromatography and modified polyacrylamide gels, which allowed to reveal the presence of proteins with molecular weights up to 1-2 million Dalton. A novel analytical strategy based on mass spectrometry allowed to obtain the caracteristic fingerprint of each plant gum. This developed method was successfully applied on a watercolor sample dated from 1870 supplied by the Metropolitan Museum of Art (New York, USA)
Bres, Jean-Charles. "Synthèse de prodrogues d'oligonucléotides et étude de leur métabolisation en milieux biologiques suivie par spectrométrie de masse MALDI-TOF. Synthèse de pro-oligonucléotides N-acétylés". Montpellier 2, 2002. http://www.theses.fr/2002MON20122.
Texto completo da fonteSeng, Piseth. "Application de la spectrométrie de masse MALDI-TOF en microbiologie clinique". Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM5033/document.
Texto completo da fonteThe objective of this thesis is to apply the method of bacterial identification by MALDI-TOF MS in daily practice in a routine clinical microbiological laboratory. Firstly, we prospectively evaluated the performance and the cost-effective of bacterial identification by MALDI-TOF in comparison with conventional phenotypic identification methods. During a 16-week study, we compared the performance of MALDI-TOF with conventional techniques of identification including Gram staining, API ANA identification strip and automated identification using the Vitek 2. The unmatched identifications between MALDI-TOF and conventional methods were resolved by molecular identification. In this study, we showed that MALDI-TOF was an effective tool and less expensive for the rapid identification of bacterial species in clinical microbiology laboratory. MALDI-TOF can be used in first intention for identification before Gram staining or other phenotypic identification techniques based on physicochemical properties of bacteria. Secondly, we retrospectively evaluated the performance and the cost-effectiveness of the exclusive use of MALDI-TOF in bacteriological diagnosis in comparison with conventional phenotypic identification. 11-year retrospective analysis of data showed that MALDI-TOF was efficient and completely adapted for the routine identification of bacterial species. We also showed that MALDI-TOF had capacity to identify bacterial species that were rarely involved in human diseases. This technique could be an alternative to molecular methods in the clinical laboratory
Vanvlassenbroeck, Aurélien. "Etude expérimentale et in silico du potentiel de synthèse NRPS chez les Pseudomonas fluorescents". Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10044/document.
Texto completo da fonteThe non-ribosomal peptide synthesis is performed by large multienzymatic complexes, called synthetases, which allow the synthesis of a peptide by a way independent of the intervention of the ribosomes. The peptides produced by this synthetic way (NRPS) are widely studied and various bioinformatics analysis tools that allow the prediction of the structure of the synthetase and the composition of his product, are available. This kind of peptide synthesis has been described in several microorganisms. Our choice focus on the fluorescent pseudomonads producing two types of NRPS, the cyclic lipopeptides (CLPS) and siderophores, the most represented is the pyoverdin. The study of these NRPS was performed by experimental and bioinformatics analysis. This work has demonstrated the potential of non-ribosomal synthesis by a bioinformatics study of the 20 avalaible genomes of Pseudomonas. Study of pyoverdine synthetases and extracting signatures of adenylation domains (A) have allowed to improving the prediction of the avalaible tools. Feeding experiments followed by MALDI-TOF helped to highlight permissive A domains in pyoverdins synthetases
Mériaux, Céline. "Imagerie du système nerveux central par spectrométrie de masse MALDI". Thesis, Lille 1, 2011. http://www.theses.fr/2011LIL10059/document.
Texto completo da fonteIn recent years, MALDI mass spectrometric imaging has proved to be a powerful tool for biomarker research. This technology allows the analysis of a wide range of endogenous and exogenous compounds in tissue sections. Many developments need to be undertaken to improve the detection of molecules. The sample preparation, including chemical treatment and deposition of the matrix, is dependent on the tissue and molecules of interest and influences the quality of spectra and images. In addition, the bioinformatics tools such as multivariate analysis provide informations on the markers according to phenotypes. These steps are crucial for imaging applications in the field of biology. First of all, we focused on the development of new matrices suitable for MALDI imaging such as ionic matrices. Secondly, these developments have been applied to the invertebrate model, the medicinal leech, at embryonic and adult stages, to compare the biological mechanisms involved in the establishment of the central nervous system and nerve regeneration after injury of this system. Finally, studies of neurological damage have been undertaken to understand the key factors involved in the balance regeneration/degeneration. Thus, studies of human hippocampi samples have revealed the existence of proteins associated with a particular distribution corresponding to layers of neurons abnormally present in the hippocampus of epileptic patients
Hillion, Mélanie. "Interactions peau/microbiote cutané : étude du microbiote cutané cultivable et influence de produits cosmétiques sur la virulence bactérienne. Apports de la technique de spectrométrie de masse MALDI-TOF". Rouen, 2013. http://www.theses.fr/2013ROUES024.
Texto completo da fonteFotso, Fotso Aurélien. "Investigation des fièvres récurrentes en Afrique". Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM5032/document.
Texto completo da fonteIn Africa, relapsing fever borreliae are neglected arthropod-borne pathogens causing mild to deadly septicemia and other clinical manifestations, particularly abortion in pregnant women. Four different species of Borrelia, initially distinguished one from another on the basis of geography and vector, are currently cultured causative agents in Africa: Borrelia crocidurae, Borrelia duttonii, Borrelia recurrentis et Borrelia hispanica. These different species are circulating in parallel to at least six not-yet cultured species in vectors. Our work consisted in the investigation of recurrent fevers borreliosis in Africa. We have developed rapid detection in MALDI-TOF mass spectrometry of Borrelia in ticks by creating a prior a Borrelia MALDI-TOF-MS database. The Borrelia database and a custom software program that subtracts the uninfected O. sonrai profile were used to detect B. crocidurae in 20 O. sonrai ticks, including eight ticks that tested positive for B. crocidurae by PCR-sequencing; which paves the way for the use of MALDI-TOF-MS for the dual identification of vectors and vectorized pathogens. We have also illustrates a non-specialized circulation of B. crocidurae borreliae within a collection of 35 O. sonrai ticks in West Africa. These ticks were genotyped by 16S rRNA mitochondrial gene sequencing while B. crocidurae was genotyped by Multispacer Sequence Typing (MST). The 35 ticks were grouped into 12 genotypes strong geographic structuring and 35 B. crocidurae into 29 genotypes without strict geographic structure. One O. sonrai genotype carried several B. crocidurae genotypes and one B. crocidurae genotype was found in different O. sonrai genotypes
Briet, Arnaud. "Étude de la flore bactérienne et de sa résistance aux antibiotiques des produits de la pêche et de l'aquaculture". Thesis, Littoral, 2018. http://www.theses.fr/2018DUNK0494/document.
Texto completo da fonteAntimicrobial resistance is a threat to global public health. Human can be contaminated by antibiotic resistant bacteria through food. However, data on antimicrobial resistant bacteria in seafood are scarce. The aim of this thesis was to study seafood bacterial flora and its antimicrobial resistance. First, mesophilic flora was obtained from 9 matrixes and MALDI-TOF and housekeeping genes sequencing technics were used to identify isolates. Antimicrobial resistance of most frequently bacteria were tested. In total, 1882 isolates were obtained and 150 bacterial species and 57 genera were identified. Enterococcus, Staphylococcus, Exiguobacterium, Pseudomonas, Vibrio and Proteus were most frequently isolated and their antimicrobial resistance was studied. Antibiotic resistant bacteria accounted for 46% of isolates and multidrug resistant bacteria accounted for 3% of isolates. Antimicrobial resistant bacteria were mostly isolated from shrimps. On a side study, antimicrobial resistance of a V.parahaemolyticus strain collection isolated from seafood was characterized. Antimicrobial resistant strains accounted for 15% and multi-drug resistant bacteria accounted for 3%. A NDM-1-producing multidrug resistant strain, 16-B3PA-006 was identified from shrimps imported from South-East Asia
Longuespée, Rémi. "Histologie moléculaire : développements et applications pour la recherche de biomarqueurs du cancer de l’ovaire". Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10045/document.
Texto completo da fonteEpithelial ovarian Cancers (EOC) are amongst the most deadly gynecological neoplastic afflictions in western countries. As this time, there is no method for the efficient screening of the disease in its early steps of development. The topics of this PhD are based on two objectives related to biomarkers research of EOC. The first one was the development of analytical methods for MALDI Mass Spectrometry for global biomarkers screenings in different types EOC. An extraction procedure for high molecular mass proteins on tissue sections has been designed in order to push back the limits of sensitivity of the method. Then, multivariate analyses allowed us to compare spectral informations contained in histological regions of different natures. All these developments conducted to the histopathological validation of a biomarker of immunosupression associated to ovarian cancer, namely the C-terminal fragment of PA28 (Reg-Alpha). Another issue, the determination of EOC origin, has also been studied. The second goal of this PhD has been the exploration of the relative implication of the different members of proproteine convertases (PCs) in EOC, which are keys enzymes involved in the maturation of many molecular actors of tumoral progression. To do so, SKOV-3 cell lines have been knocked-down for different PCs to study the functional redundancy of these enzymes. It has then been possible to determine, in cellulo and in vivo, that PACE4 is particularly influent on ovarian cancer progression
Mallah, Khalil. "In depth systemic biology analysis of central nervous system injuries". Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1S108/document.
Texto completo da fonteIn the context of studying biological alterations occurring post impact to the central nervous system, my thesis was focused on studying the proteomic and lipid changes occurring post injury to the brain and spinal cord. A fundamental spatio-temporal study was conducted on an open-head rat TBI model to identify potential injury-specific markers. Using MALDI MSI, we performed 3D reconstruction of the injured brain at 3 days after injury and depicted lesion-specific m/z lipid molecules. After, MALDI MSI was applied on the acute/sub-acute time frame post impact: 1 day, 3 days, 7 days, and 10 days. In parallel, a microproteomic analysis was carried out on tissue segments directly consecutive to the imaged ones in an approach to correlate both lipid and protein changes. Our results yielded the identification of a family of lipids, acylcarnitines, which are expressed within the injured cortex with maximum intensity 3 days post impact. These lipid molecules also were found to be expressed in the substantia nigra and microproteomics data showed an upregulation in expression of Parkinson’s related proteins. Taken altogether, our results depict a role of link between mild-TBI and Parkinson’s disease as early as 3 days post impact, with a possible role of acylcarnitine. This same family of molecules was also present in SCI. In a therapeutic approach previous results showed RhoA protein as a major candidate post impact in SCI. After using RhoA inhibitor treatment, a proteomic study was carried out to investigate its impact on SCI. The results showed that both in-vivo and in-vitro treatment with RhoA inhibitor stimulated neurite outgrowth and helped in axonal regeneration
Seyer, Alexandre. "Imagerie par spectrométrie de masse : développements méthodologiques et applications biologiques". Thesis, Evry-Val d'Essonne, 2010. http://www.theses.fr/2010EVRY0028/document.
Texto completo da fonteMy PhD’s work consisted in continuing the development of Mass Spectrometry Imaging (MSI) methods, in terms of methodology improvements but also through biological applications.The first part concerned the development of a novel sample preparation method dedicated to very small objects for chemical imaging, particularly for TOF-SIMS imaging. This method has been validated by studying different types of flavonoids in from seeds of Arabidopsis thaliana, with a size of 400 nm only. The second part, dedicated to biological applications, is divided into two sections. The first section includes two projects where the goals was to detect and locate, using TOF-SIMS imaging, the active molecule of an anti-acne cream in human skin sections, and a brominated flame retardant, the decabromodiphenyl ether, in target tissues in rats. In the second section, we have studied by MALDI-TOF and TOF-SIMS imaging the lipid absorption during the digestion, and finally, with the help of statistical analysis tools, we compared lipid profiles of healthy samples versus those from cystic fibrosis samples in a model animal of the disease.Through these projects, we have concluded that MALDI-TOF and TOF-SIMS imaging are two complementary techniques, and, when they are combined with statistical analysis, they can be powerful tools
Sueur, Maxime. "Characterization of organic aerosols from ship emissions by high resolution mass spectrometry : Development of new analytical methods and data visualization software". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMR006.
Texto completo da fonteOrganic aerosols (OA), whether of anthropogenic or natural origin, have a major impact on the environment, both in terms of climate changes and health effects. Among the many sources of OA, the maritime transport sector occupies a far from negligible place, on the one hand, because of the annual volume of exhaust emitted and their nature, and on the other because of the proximity of emissions to inhabited areas such as ports or coastlines. Although the composition of these exhausts is monitored by means of routine analyses, it is important to study them in depth in order to fine-tune regulations on marine traffic. However, the analysis of the molecular-scale composition of a mixture as complex as ship emissions requires the use of techniques such as mass spectrometry (MS), and in particular Fourier transform mass spectrometry (FTMS). However, FTMS generates a large amount of data and generally requires the use of processing and visualization software to extract and highlight relevant information. Also, although FTMS provides information on the molecular composition of a sample, this technique does not allow the evaluation of the isomeric diversity, unlike ion mobility spectrometry (IMS). So, with the aim to characterize ship emissions, we adopted three lines of work: the development of open-access software under Python to facilitate the processing and visualization of FTMS data for the characterization of complex mixtures, the targeted characterization of petroporphyrins in naval fuels and their combustion products by Fourier transform ion cyclotron resonance (FTICR) mass spectrometry using electron transfer matrix-assisted laser desorption/ionization (ET-MALDI), and the study of structural modifications caused by photochemical aging on ship emissions using IMS-MS