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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Site-specific glycoconjugate synthesis / Synthèse site-spécifique de glycoconjugués

Bayart, Caroline 08 December 2017 (has links)
Les vaccins conjugués furent développés suite à l’inefficacité des vaccins polysaccharidiques chez les nourrissons et les personnes âgées. Les vaccins conjugués sont composés d’un polysaccharide extrait de la capsule bactérienne et d’une protéine porteuse. Celle-ci permet de décupler la réponse immunitaire, permettant aux vaccins d’être efficaces. L’évolution des connaissances en chimie et en analytique permettent aujourd’hui de mieux caractériser ces vaccins et de mieux maîtriser leur production. Cependant, les chimies de conjugaison utilisées pour lier le polysaccharide et la protéine porteuse, ne sont pas toujours définies et cela mène souvent à l’obtention de produits hétérogènes. Les objectifs de cette thèse ont été d’étudier le polysaccharide, les protéines porteuses et de nouvelles voies de conjugaisons pour lier spécifiquement ces deux biomolécules.Différents outils analytiques ont été utilisés afin d’acquérir une meilleure connaissance des deux partenaires de conjugaison. Cela a également permis d’établir une stratégie d’analyse efficace pour caractériser les produits de réaction. La spécificité des réactions de conjugaison a été induite par l’utilisation d’espaceurs bi-fonctionnels, réagissant spécifiquement sur certains acides aminés. Leur réactivité a d’abord été testée sur un modèle peptidique. Cela a permis de faciliter la caractérisation et d’étudier l’efficacité et la spécificité des réactions. Les réactions efficaces ont ensuite été testées différents modèles : de la protéine au vaccin. Sur les quatre réactions testées, une a été efficace sur tous les modèles. Cette chimie de conjugaison est prometteuse pour le développement de nouveaux vaccins / Conjugate vaccines were developed because polysaccharide vaccines were not efficient in infant and old people. These vaccines were composed of the polysaccharide extracted from the bacterial capsule linked to a carrier protein. This protein created an immunological boost which allowed the vaccine to induce a proper protection for everyone. As chemistry knowledge and analytical techniques evolved, vaccines can now be better characterized and the production can be better controlled. Nevertheless, the chemistries used to bind the polysaccharide and the carrier protein are not always well-defined, which leads to the production of heterogeneous products. The objectives of this PhD were to study the polysaccharide, carrier proteins and new conjugation chemistries to specifically bind the two biomolecules. The other challenge was to be able to check the reaction specificity and characterize reaction products.To do so different analytical tools were used to allow a better knowledge of both conjugation partners but also to establish an efficient analytical strategy for glycoconjugate characterization. Conjugation reactions specificity was induced by using different bi-functional linkers, reacting specifically for one type of amino acid. Linkers’ reactivity was first tested on a model peptide. This allowed to facilitate the characterization and to check for both reaction specificity and reaction success. Efficient reactions were then tested on different models from carrier proteins to glycoconjugate vaccines. One of the four tested reactions was efficient from the peptide to the vaccine model. This conjugation is thus promising for the development of new conjugate vaccines
22

Impacto de la vacuna conjugada antineumocócica sobre la incidencia, hospitalización y mortalidad por casos de neumonía en menores de 05 años en el Perú, 2001-2019 / Impact of the pneumococcal conjugate vaccine on the incidence, hospitalization, and mortality due to pneumonia cases in children under 5 years of age in Peru, 2001-2019

von Koeller Jones, Beatrix Marie, Velásquez Sack, Romina Valeria 04 March 2022 (has links)
ortalidad en niños menores de 5 años, a pesar de contar con medidas preventivas como la vacunación.  Objetivo: Evaluar el impacto de la vacuna antineumocócica conjugada sobre la incidencia de neumonía en niños menores de 5 años, a nivel nacional y departamental, así como las hospitalizaciones y mortalidad a nivel nacional, desde 2001-2019 en el Perú. Además, realizar un análisis entre departamentos con coberturas altas de vacunación y aquellos que alcanzan coberturas bajas.  Metodología: Diseño: Series de tiempo definidas por la introducción de la vacuna antineumocócica heptavalente (PCV7) en el periodo de tiempo entre 2009 y 2011 a nivel nacional y departamental. Posteriormente, se realizó un análisis multivariado contrastando la incidencia de casos entre los departamentos con alta y baja cobertura de vacunación. Procedimiento de obtención de datos: Los datos agrupados sobre la incidencia, hospitalización y mortalidad por neumonía fue obtenida de la CDC (Centro de Enfermedades Contagiosas); la cobertura de vacunación fue obtenida como base de datos del Ministerio de Salud (MINSA) Análisis específicos: se realizó un análisis multivariado contrastando la incidencia de casos de neumonía entre los departamentos con alta y baja cobertura de vacunación.  Resultados: Para las hospitalizaciones a nivel nacional, la tendencia de cambio post vacunación fue negativa y significativa (p <0.001). La incidencia y mortalidad tuvieron cambios no significativos. A nivel regional, Callao, Lima, Moquegua, Cusco, Huancavelica, Pasco, Loreto, San Martín y Ucayali tuvieron tendencia de cambio post vacunación negativa y significativa (p <0.001). Conclusiones: La vacunación ha demostrado ser efectiva para disminuir hospitalizaciones por neumonía en algunos departamentos y a nivel nacional. Sin embargo, existen factores individuales que pueden alterar la efectividad de la intervención, propias de la estrategia aplicada y del tipo de estudio utilizado. / Introduction: Pneumonia is an acute respiratory infection, the most common bacterial cause is Streptococcus pneumoniae and represents one of the major causes of mortality in children under 5 years of age, despite preventive measures. Objective: Assess the impact of the pneumococcal vaccine on the incidence of pneumonia in children under 5 years of age, at the national and departmental level, as well as hospitalizations and mortality at the national range, over 2001-2019 in Peru. In addition, perform an analysis between departments that achieve high vaccination coverage and those with low coverage.  Methodology: Study design: Time series interrupted by the inclusion of the heptavalent pneumococcal vaccine (PCV7) in the period between 2009 and 2011 at the national and departmental level. Multivariate analysis, contrasting the incidence of cases between departments with high and low vaccination coverage. Data collection procedure: Pooled data on pneumonia incidence, hospitalization, and mortality obtained from the CDC (Center for Communicable Diseases); vaccination coverage obtained as a database from the Ministry of Health (MINSA) Specific analyzes: multivariate contrasting the incidence of pneumonia cases between departments with high and low vaccination coverage. Results: Hospitalizations at the national level had a negative trend of change after vaccination (p <0.001). At regional level, Callao, Lima, Moquegua, Cusco, Huancavelica, Pasco, Loreto, San Martín and Ucayali had a negative and significant change trend post vaccination (p <0.001). Conclusions: Vaccination has proven to be effective in some departments and at the national level. However, there are individual factors and limitations of the study that may affect the outcome. / Tesis
23

Variations temporelles et géographiques des méningites à pneumocoque et effet du vaccin conjugué en France / Temporal and geographic variation of pneumococcal meningitis and effect of conjugate vaccine in France

Alari, Anna 30 November 2018 (has links)
Streptococcus pneumoniae est une bactérie cocci gram positif commensale de la flore oropharyngée qui colonise le rhinopharynx de l’Homme et dont près de 100 sérotypes sont connus. Les nourrissons et les jeunes enfants représentent son réservoir principal. Le pneumocoque peut être à l’origine d’infections graves, telles que la méningite, les bactériémies et la pneumonie, et moins graves mais plus courantes comme la sinusite et l’otite moyenne aiguë. Deux vaccins anti-pneumococciques conjugués ont été introduits en France : le PCV7 (couvrant contre 7 sérotypes) en 2003 et le PCV13 (couvrant contre 6 sérotypes supplémentaires) en 2010. L’objectif général de ce travail de thèse est d’évaluer l’impact des politiques vaccinales sur les infections invasives à pneumocoque en France, en s’intéressant principalement aux évolutions temporelles et géographiques des plus graves : les méningites à pneumocoque (MP). Un premier travail a étudié les dynamiques temporelles des MP sur la période 2001–2014 afin d’identifier l’impact de l’introduction des vaccins conjugués. Des techniques statistiques de modélisations adaptées aux séries temporelles ont été utilisées. Les résultats de ce travail retrouvent des effets rapportés dans la littérature : une réduction des MP à sérotypes vaccinaux mais aussi une augmentation des MP dues aux sérotypes non inclus dans le vaccin (phénomène de « remplacement sérotypique »).Par conséquent, le premier bénéfice, à l’échelle de la population générale, de l’introduction de cette vaccination a été observé seulement onze ans après l’introduction du PCV7, et principalement suite à l’introduction du PCV13 en 2010, avec une diminution de 25% du nombre de MP en 2014. La composante géographique a ensuite été prise en compte afin d’étudier le rôle de la de couverture vaccinale dans la variabilité des MP annuelles entre les départements sur la période 2001-2016. Les résultats confirment l’efficacité des deux formulations du vaccin sur les MP dues aux sérotypes vaccinaux et suggèrent une certaine homogénéité de cet effet entre les différents départements. Inversement, le remplacement sérotypique a été confirmé mais uniquement suite à l’introduction de la première formulation du vaccin et ces effets présentent une répartition géographique hétérogène et variable. La variabilité de la couverture vaccinale entre les départements n’explique pas celle observée dans le nombre de MP, ce qui suggère l’intervention d’autres facteurs tel que la densité géographique. Enfin, une modélisation dynamique, permettant de prendre en compte des aspects fondamentaux des dynamiques de transmission et d’infection du pneumocoque non intégrés dans les méthodes de modélisation statique, a été proposée afin de prédire l’impact de différentes stratégies de vaccination pour les adultes de 65 ans et plus et ainsi évaluer leur rapport coût-utilité. / Streptococcus pneumoniae is a Gram-positive commensal bacterium of the oropharyngeal flora usually colonizing human’s rhino pharynx, of which almost 100 serotypes are known. Infants and young children constitute its main reservoir. Pneumococcus may cause serious infections, such as meningitis, bacteremia and pneumonia, or less serious but more common such as sinusitis and acute otitis media (AOM). Two conjugate pneumococcal vaccines have been introduced in France: PCV7 (covering 7 serotypes) in 2003 and PCV13 (covering 6 additional serotypes) in 2010. The overall objective of this thesis is to assess the impact of vaccination policy on invasive pneumococcal diseases in France, by focusing on temporal and geographical trends of the most serious of them: pneumococcal meningitis (PM). An initial study of PMs temporal dynamics over the 2011-2014 period assessed the impact of conjugate vaccines’ introduction. Statistical modeling techniques were used for time series analysis. The results confirm the effects found in literature: a reduction of vaccine serotypes PMs but at the same time an increase of PMs, due to non-vaccine serotypes (effect of “serotype replacement”). Therefore, the first benefit of vaccine introduction at population scale has been observed no less than 11 years after PCV7 introduction, and then principally after PCV13 was introduced in 2010, with a 25% decrease in PMs in 2014. The geographic component was then implemented to analyze the role of vaccine coverage in annual PM variability between geographic units over the 2001-2016 period. Results confirm the effectiveness of both vaccine compositions on vaccine serotypes PMs and suggest homogeneity of this effect among geographic units. Conversely the serotype replacement has been confirmed only after the first vaccine composition was introduced and presents a variable and heterogeneous geographical repartition. Variability in vaccine coverage among geographic units doesn’t explain the differences in PMs, which could suggest the role of others factors such as demographic density. Finally, a dynamic modeling capable of taking into consideration fundamental aspects of pneumococcus transmission and infection mechanisms not integrated in static modeling has been proposed in order to predict the impacts of different vaccination strategies for 65+ adults and therefore assess their cost-utility ratios.
24

Impacto da vacina pneumocócica conjugada 10-valente (PCV10) na hospitalização de crianças por pneumonia em Goiânia: uso de dados primários e secundários / Assessing PCV10 impact in children hospitalized with pneumonia in Goiânia: using primary and secondary data

Andrade, Sabrina Sgambatti de 17 July 2015 (has links)
Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2015-11-12T12:16:48Z No. of bitstreams: 2 Tese - Sabrina Sgambatti - 2015.pdf: 2847998 bytes, checksum: 069ae0ef61790cc3dd2564c3e7fa9120 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-11-12T12:21:22Z (GMT) No. of bitstreams: 2 Tese - Sabrina Sgambatti - 2015.pdf: 2847998 bytes, checksum: 069ae0ef61790cc3dd2564c3e7fa9120 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-11-12T12:21:22Z (GMT). No. of bitstreams: 2 Tese - Sabrina Sgambatti - 2015.pdf: 2847998 bytes, checksum: 069ae0ef61790cc3dd2564c3e7fa9120 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-07-17 / Background. Anticipating the introduction of the 10-valent pneumococcal conjugate vaccine (PCV10) on childhood National Immunization Program (NIP), an active population-based surveillance on pneumonia hospitalizations was conducted as a baseline, enabling a vaccination impact study. The objectives of the present research were: (i) to assess the reliability of the Hospital Information System of the Unified Health System (SIH-SUS) as a data source for assessing PCV10 impact on pneumonia; (ii) to measure the impact of vaccination with PCV10 in reducing the incidence of clinical and X-Ray confirmed pneumonia, in children residing in Goiânia municipality. Methods. In this study, we conducted an active prospective population-based surveillance on pneumonia in the post PCV10 vaccination period (2011-2013), in all 17 pediatric hospitals of Goiânia, with similar methodology used in the previous pneumonia surveillance during the pre vaccination period (2007-2009). Children aged 2-35 months of age, admitted to hospitalization with suspected diagnosis of pneumonia, were elegible for the survey. Clinical pneumonia and X-Ray confirmed pneumonia were the outcomes. The intervention was the PCV10, introduced in June 2010 in Goiania. Probabilistic linkage was performed between the SIH-SUS database (secondary data) and the active population surveillance (primary data) for the year 2012, to measure the agreement of case identification on pneumonia hospitalization rates between both data sources. To assess the impact of PCV10, annual incidence of clinical pneumonia and X-Ray confirmed pneumonia (per 100,000 population) and respective 95% confidence interval (95%CI) was estimated for the post vaccinations period and compared to the rates obtained for the pre vaccination period. The relative risk for pneumonia and respective 95%CI were calculated based on Poisson distribution. The percentage change in rates (1-relative risk) between pre and post vaccination periods was calculated. Results. Pneumonia incidence rates obtained by the SIH-SUS were statistically similar to those obtained by active population surveillance for children 2-23meses (p = 0.184). On the PCV10 impact evaluation study, the rates of hospitalization for clinical and RXT confirmed pneumonia in children under 24 months decreased 13.1% (from 5,728/100,000 to 4,976/100,000) and 25.4% (from 2,497/100,000 to 1,862/100,000), respectively, after routine immunization. / Introdução. Antecipando a introdução da vacina pneumocócica conjugada 10-valente (PCV10) no calendário de vacinação infantil do Programa Nacional de Imunizações (PNI), um estudo de vigilância de base populacional ativa foi conduzido como linha de base, possibilitando, assim, avaliar o impacto da vacinação nas hospitalizações por pneumonia. Assim, os objetivos desta investigação foram: (i) avaliar a confiabilidade do Sistema de Informações Hospitalares do Sistema Único de Saúde (SIH-SUS) como fonte de dados para estudos de avaliação de impacto da PCV10 nas pneumonias; (ii) avaliar o impacto da vacinação com a PCV10 na redução da incidência de hospitalizações de crianças com pneumonia clínica e confirmada por Raio-X de tórax (RXT), residentes no município de Goiânia. Métodos. Neste estudo, conduzimos uma vigilância populacional prospectiva, ativa, de pneumonias no período pós vacinal (2011-2013) em 17 hospitais pediátricos de Goiânia, com metodologia similar à conduzida em estudo anterior, no período pré vacinal (2007-2009). Foram elegíveis para o estudo crianças de 2 a 35 meses de idade, admitidas com com diagnóstico inicial de pneumonia. Os desfechos foram pneumonia clínica e pneumonia confirmada por RXT. A intervenção foi a PCV10, introduzida em junho de 2010 em Goiânia. A técnica de linkage probabilístico foi utilizada para vincular o banco de dados do SIH-SUS (dados secundários) e o da vigilância populacional ativa (dados primários) referentes ao ano de 2012, e desta forma, avaliar a concordância no diagnóstico e nas taxas de hospitalização por pneumonia entre as duas fontes de dados. Para avaliar o impacto da PCV10, calculou-se a incidência anual de pneumonia clínica e confirmada por RXT (por 100.000 habitantes) e respectivos intervalos de 95% de confiança (IC95%) para o período pós vacinal, e comparou-se com as taxas do período pré vacinal. O risco relativo para pneumonia e respectivos IC95% foram calculados com base na distribuição de Poisson. O percentual de mudança entre as taxas pré e pós vacinal foi calculado como 1-risco relativo. Resultados. As taxas de pneumonia obtidas pelo SIH-SUS foram estatisticamente similares às obtidas por vigilância populacional ativa para as crianças de 2-23meses (p=0,184). No estudo de avaliação do impacto da PCV10, as taxas de hospitalização por pneumonia clínica e confirmada por RXT em crianças menores de 24 meses reduziram 13.1% (de 5,728/100,000 para 4,976/100,000) e 25.4% (de 2,497/100,000 para 1,862/100,000), respectivamente, após a vacinação de rotina. Conclusões. Dados do SIH-SUS podem ser utilizados para avaliar o impacto da PCV10 nas hospilazações por pneumonia na infância. Após 3 anos de vacinação com a PCV10 em Goiânia, observou-se significante queda das taxas de hospitalização por pneumonia clinica e confirmada por RXT em crianças alvo do PNI.
25

Infectious and bleeding complications in patients with hematological malignancies : Studies on diagnosis and prevention

Svensson, Tobias January 2017 (has links)
The overall aim of this thesis is to improve knowledge about the prevention of infectious and bleeding complications in patients with hematological malignancies, primarily in those with chronic lymphocytic leukemia (CLL) and myelodysplatic syndrome (MDS). Hypogammaglobulinemia, impaired production of immunoglobulins (Ig), is an established risk factor for infection, but the impact of IgG pure subclass deficiency (IgG subclass deficiency with adequate production of IgG, IgA, and IgM) has been debated. In a retrospective single institution study, we concluded that pure IgG subclass deficiency in CLL patients is rare and is not associated with an increased risk of infection. Hence, routine analysis of IgG subclasses in patients with CLL is not warranted. There is no consensus on recommending vaccination against Streptococcus pneumoniae to CLL patients mainly because comparative studies are lacking. In our randomized trial, the efficacy of a conjugated pneumococcal vaccine on immune response was superior or equal to a polysaccharide vaccine for all pneumococcal serotypes common for the two vaccines. A conjugate pneumococcal vaccine should therefore be included in vaccination programs for patients with CLL. Bronchoalveolar lavage (BAL) is a well-established invasive method to identify the cause of pulmonary infiltrates in immunocompromised patients. In a retrospective trial, we have studied the diagnostic yield of BAL in patients with hematological malignancies. We concluded that BAL is highly useful in either verifying or excluding some of the important respiratory tract infections affecting these patients, particularly invasive pulmonary aspergillosis (IPA) and Pneumocystis jirovecii pneumonia (PJP). However, standardized procedures for BAL sampling should be continually revised to avoid unnecessary microbiological tests. Thrombocytopenia, an adverse prognostic factor in patients with MDS, can be aggravated by azacitidine, first-line treatment for high-risk MDS. Eltrombopag, a thrombopoietin-receptor agonist (TPO-R), alleviates thrombocytopenia in patients with immune thrombocytopenic purpura (ITP). In a phase I clinical trial, we concluded that the combination of eltrombopag and azacitidine in high-risk MDS patients with thrombocytopenia is feasible and well tolerated in doses up to 200 mg eltrombopag daily.

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