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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.
51

Etude de l'infection par Bordetella pertussis dans un modèle de coqueluche chez le primate non-humain : Apports de l'imagerie in vivo / Bordetella pertussis infection study in a non-human primate model of whooping cough : in vivo imaging contribution

Naninck, Thibaut 28 November 2018 (has links)
La coqueluche est une pathologie due à la bactérie Bordetella pertussis qui touche les voies respiratoires des patients infectés causant toux, leucocytose, fièvre, et dont les symptômes peuvent aller jusqu’au décès chez les individus les plus à risque (nouveau-nés et enfants immunodéprimés en particulier). Ciblée par différents programmes vaccinaux depuis de nombreuses années, cette pathologie sévit à nouveau dans de nombreux pays développés où le nombre de cas augmente fortement depuis la fin des années 2000. Cette résurgence montre la nécessité de développer de nouvelles stratégies afin de comprendre les mécanismes de l’infection par B. pertussis. Dans ce contexte, la recherche préclinique apparaît comme essentielle pour comprendre la physiopathologie de la coqueluche. De nombreux modèles animaux ont été décrits pour l’étude de la coqueluche mais aucun de ces modèles ne permet de reproduire l’ensemble du spectre des symptômes cliniques de la pathologie, notamment la toux. Cependant, au cours des dernières années un modèle d’infection par Bordetella pertussis chez le jeune babouin a été développé aux Etats-Unis et permet de reproduire la pathologie observée chez l’homme, notamment concernant la toux et la transmission. Ce modèle semble ainsi très prometteur pour l’étude de la physiopathologie de la coqueluche.Cependant, de nombreuses inconnues subsistent dans ce modèle, notamment concernant la colonisation bactérienne et les interactions entre la bactérie et l’hôte. Nous avons ainsi cherché dans cette étude à évaluer d’une part l’impact de différents facteurs comme l’âge des animaux, la dose d’infection ainsi que la voie d’exposition sur la pathologie déclarée par les babouins suite à l’infection par la souche B1917 de B. pertussis afin de pouvoir proposer un parallèle avec les données cliniques disponibles. Nous avons également développé l’utilisation de techniques d’imagerie in vivo comme l’endomicroscopie confocale couplée à la bronchoscopie afin d’étudier la localisation et la cinétique de colonisation et certaines interactions du pathogène dans le tractus respiratoire inférieur au cours de la pathologie. Cette étude nous a ainsi permis d’approfondir les connaissances de physiopathologie de la coqueluche dans ce modèle babouin et consolidera cet outil précieux pour l’évaluation des futures stratégies de prévention contre cette pathologie. / Whooping cough, or pertussis, is a respiratory disease caused by Bordetella pertussis bacterial colonization of human airways. Main symptoms are cough, leukocytosis, fever and may even be lethal for some patients (e.g. newborn infants and immuno-deficient patients). Despite a good vaccination coverage worldwide against pertussis, whooping cough cases have been re-increasing in several developed countries in the past twenty years. This resurgence points out the crucial need to develop new control strategies and to better understand pertussis pathophysiology, notably using appropriate animal models. Numerous preclinical models including mice, rats, rabbits and swine have been described for B. pertussis infection studies. However, none of these models reproduce the full spectrum of clinical pertussis symptoms, especially cough. The recent baboon model of whooping cough described in the last few years in the US appears to be a very relevant model for pertussis pathophysiology studies as these animals reproduced all clinical symptoms as observed in humans including cough.However, many aspects of bacterial colonization and interactions with the host have yet to be described in this model.We have then evaluated diverse parameters such as animal age, the inoculum dose and the exposition route on the pathology symptoms and immune responses developed by baboons following B. pertussis B1917 strain inoculation in order to draw a parallel with human clinical data. We also developed in this model in vivo imaging techniques like confocal endomicroscopy coupled with bronchoscopy in order to evaluate bacterial colonization kinetics, localization and some interactions in the lower respiratory tract of infected baboons. Then, this study brought additional data on whooping cough physiopathology in this baboon model, which will be crucial for evaluating future prevention strategies against pertussis disease
52

Characterization of the biophysical and cellular aspects of pertussis toxin binding

Millen, Scott H. 19 April 2011 (has links)
No description available.
53

Adesão de profissionais de saúde do Hospital das Clínicas da FMUSP à imunização com a vacina difteria, tétano e pertussis acelular do adulto (dTpa) / Healthcare workers adherence to tetanus-diphtheria-acellular pertussis (Tdap) vaccine in Hospital das Clínicas da FMUSP

Randi, Bruno Azevedo 04 December 2018 (has links)
Introdução: A vacina tríplice acelular de adultos (dTpa) foi introduzida no Programa Nacional de Imunizações (PNI) em novembro de 2014, sendo recomendada para gestantes e profissionais de saúde (PS) que têm contato com gestantes e recém-nascidos. De abril a dezembro de 2015, foram implementadas várias estratégias para aumentar a cobertura vacinal entre os profissionais do Instituto Central do Hospital das Clínicas da FMUSP. Objetivos: Avaliar a cobertura vacinal entre os PS após implementação de cada estratégia e ao término de um ano; avaliar as variáveis associadas à vacinação; e avaliar os principais motivos de não vacinação entre os PS com indicação para tal. Métodos: Estratégias implementadas: divulgação, no boletim do hospital, de texto relembrando da necessidade de vacinação de coqueluche; reforço da necessidade da vacinação, via correio eletrônico, para as chefias de enfermagem das Divisões de Clínica Obstétrica, Neonatologia e Anestesia; aulas sobre a vacina dTpa nas reuniões científicas das Divisões de Clínica Obstétrica e Neonatologia; e vacinação ativa dos profissionais na Divisão de Clínica Obstétrica, Neonatologia e Anestesia. A cobertura vacinal foi avaliada ao fim de cada mês até abril de 2016, por meio do sistema informatizado de vacinação usado no CRIE-HC. Foi usado o modelo de regressão de Poisson com variância robusta para avaliação das variáveis associadas com a vacinação com dTpa. As razões de prevalência foram calculadas e seus intervalos de confiança de 95% estimados. Para avaliar os motivos de não vacinação, foram realizadas ligações telefônicas para os profissionais que não receberam a vacina e aplicado questionário padronizado. Resultados: Entre os 515 PS elegíveis para vacinação, 59 não possuíam registro no sistema informatizado de vacinação e foram excluídos. Assim, este estudo incluiu 456 PS. Após as intervenções, a cobertura vacinal com dTpa aumentou de 2,9% para 41,2%. As coberturas vacinais após a implementação de cada estratégia foram: 3,7% após publicação no Boletim do hospital; 10,5% após mensagem de correio eletrônico para as chefias de enfermagem; 16,2% após aula sobre a vacina em reuniões científicas das Divisões de Clínica Obstétrica e Neonatologia; 27,9% após vacinação ativa na Divisão de Clínica Obstétrica; 40,6% após vacinação ativa na Divisão de Neonatologia e 41,2% após vacinação ativa na Divisão de Anestesia. Na análise multivariada, ser médico (a), trabalhar nas Divisões de Clínica Obstétrica ou Anestesia e ter recebido a vacina de influenza de 2015 foram associados à vacinação com dTpa. Foi feito contato telefônico com 39 profissionais que não receberam a vacina em nosso serviço; apenas 9 (23%) referiram ter recebido a vacina em outros serviços; e dos 30 não vacinados, 27 (90%) alegaram desconhecimento da recomendação. Conclusões: Conhecimento sobre a doença e a recomendação de vacinação são importantes para aumentar a cobertura vacinal entre PS. Porém, mesmo sabendo do efeito cumulativo na cobertura vacinal a cada estratégia realizada, a vacinação ativa dos PS em seus locais de trabalho parece ter sido a estratégia que mais contribuiu para o aumento da cobertura. A cobertura vacinal final de dTpa permanece baixa e maiores esforços são necessários para aumentá-la / Introduction: The acellular pertussis vaccine for adults (Tdap) was introduced in the Brazilian National Immunization Program (PNI) in November 2014, being recommended for pregnant women and healthcare workers (HCWs) who have contact with pregnant women and newborns. From April to December 2015, interventions to raise Tdap coverage among HCWs of the Instituto Central do Hospital das Clínicas were implemented. Objective: To evaluate the cumulative vaccine coverage after each intervention; identify factors associated to Tdap vaccination among HCWs; and evaluate the main reasons for HCWs not receiving Tdap. Methods: Interventions implemented: a note on the hospital\'s internal newsletter, reminding HCWs of the importance of pertussis vaccination; email to the nurse´s teams leaders strengthening vaccine recommendations; lectures on pertussis and Tdap for physicians at the clinical meetings of the Obstetrics and Neonatology Clinics; on-site vaccination by mobile teams at the Obstetrics, Neonatology, and Anesthesiology Clinics. The vaccine coverage was evaluated at the end of each month until April-2016. A multivariate Poisson regression model with robust error variance was used to evaluate variables associated with Tdap vaccination. Prevalence ratios (PR) and their 95%CI were estimated. To evaluate the reasons for HCWs not to be vaccinated, those who have not received Tdap were called by phone and a standard questionnaire was applied. Results: Among 515 HCWs eligible for immunization, 59 professionals were not registered in the vaccination data system and were excluded because information about Tdap vaccine could not be achieved. The study included 456 HCWs. After the interventions, Tdap coverage raised from 2.9% to 41.2%. The vaccine coverage after each intervention was: 3.7% after a note on the hospital\'s internal newsletter; 10.5% after email to the nurse´s teams leaders strengthening vaccine recommendations; 16.2% after lectures on pertussis and Tdap for physicians at the clinical meetings of the Obstetrics and Neonatology Clinics; 27.9% after on-site vaccination by mobile teams at the Obstetrics Clinic; 40.6% after on-site vaccination at the Neonatology Clinic and 41.2% after on-site vaccination at the Anesthesiology Clinic. In the multiple analysis, occupation, working place and having received influenza vaccination in 2015 were independently associated to Tdap vaccination. Thirty-nine HCWs that have not received Tdap were contacted by phone: 90% of them claimed they did not know the vaccine recommendation. Conclusions: Knowledge about pertussis and the recommendation of vaccination are important to raise vaccine coverage between HCWs. Even knowing the cumulative effect of each strategy on vaccine coverage, HCWs vaccination in their workplaces seems to be the most effective strategy in raising coverage. The final Tdap coverage remains low and greater efforts are needed to increase it
54

Adesão de profissionais de saúde do Hospital das Clínicas da FMUSP à imunização com a vacina difteria, tétano e pertussis acelular do adulto (dTpa) / Healthcare workers adherence to tetanus-diphtheria-acellular pertussis (Tdap) vaccine in Hospital das Clínicas da FMUSP

Bruno Azevedo Randi 04 December 2018 (has links)
Introdução: A vacina tríplice acelular de adultos (dTpa) foi introduzida no Programa Nacional de Imunizações (PNI) em novembro de 2014, sendo recomendada para gestantes e profissionais de saúde (PS) que têm contato com gestantes e recém-nascidos. De abril a dezembro de 2015, foram implementadas várias estratégias para aumentar a cobertura vacinal entre os profissionais do Instituto Central do Hospital das Clínicas da FMUSP. Objetivos: Avaliar a cobertura vacinal entre os PS após implementação de cada estratégia e ao término de um ano; avaliar as variáveis associadas à vacinação; e avaliar os principais motivos de não vacinação entre os PS com indicação para tal. Métodos: Estratégias implementadas: divulgação, no boletim do hospital, de texto relembrando da necessidade de vacinação de coqueluche; reforço da necessidade da vacinação, via correio eletrônico, para as chefias de enfermagem das Divisões de Clínica Obstétrica, Neonatologia e Anestesia; aulas sobre a vacina dTpa nas reuniões científicas das Divisões de Clínica Obstétrica e Neonatologia; e vacinação ativa dos profissionais na Divisão de Clínica Obstétrica, Neonatologia e Anestesia. A cobertura vacinal foi avaliada ao fim de cada mês até abril de 2016, por meio do sistema informatizado de vacinação usado no CRIE-HC. Foi usado o modelo de regressão de Poisson com variância robusta para avaliação das variáveis associadas com a vacinação com dTpa. As razões de prevalência foram calculadas e seus intervalos de confiança de 95% estimados. Para avaliar os motivos de não vacinação, foram realizadas ligações telefônicas para os profissionais que não receberam a vacina e aplicado questionário padronizado. Resultados: Entre os 515 PS elegíveis para vacinação, 59 não possuíam registro no sistema informatizado de vacinação e foram excluídos. Assim, este estudo incluiu 456 PS. Após as intervenções, a cobertura vacinal com dTpa aumentou de 2,9% para 41,2%. As coberturas vacinais após a implementação de cada estratégia foram: 3,7% após publicação no Boletim do hospital; 10,5% após mensagem de correio eletrônico para as chefias de enfermagem; 16,2% após aula sobre a vacina em reuniões científicas das Divisões de Clínica Obstétrica e Neonatologia; 27,9% após vacinação ativa na Divisão de Clínica Obstétrica; 40,6% após vacinação ativa na Divisão de Neonatologia e 41,2% após vacinação ativa na Divisão de Anestesia. Na análise multivariada, ser médico (a), trabalhar nas Divisões de Clínica Obstétrica ou Anestesia e ter recebido a vacina de influenza de 2015 foram associados à vacinação com dTpa. Foi feito contato telefônico com 39 profissionais que não receberam a vacina em nosso serviço; apenas 9 (23%) referiram ter recebido a vacina em outros serviços; e dos 30 não vacinados, 27 (90%) alegaram desconhecimento da recomendação. Conclusões: Conhecimento sobre a doença e a recomendação de vacinação são importantes para aumentar a cobertura vacinal entre PS. Porém, mesmo sabendo do efeito cumulativo na cobertura vacinal a cada estratégia realizada, a vacinação ativa dos PS em seus locais de trabalho parece ter sido a estratégia que mais contribuiu para o aumento da cobertura. A cobertura vacinal final de dTpa permanece baixa e maiores esforços são necessários para aumentá-la / Introduction: The acellular pertussis vaccine for adults (Tdap) was introduced in the Brazilian National Immunization Program (PNI) in November 2014, being recommended for pregnant women and healthcare workers (HCWs) who have contact with pregnant women and newborns. From April to December 2015, interventions to raise Tdap coverage among HCWs of the Instituto Central do Hospital das Clínicas were implemented. Objective: To evaluate the cumulative vaccine coverage after each intervention; identify factors associated to Tdap vaccination among HCWs; and evaluate the main reasons for HCWs not receiving Tdap. Methods: Interventions implemented: a note on the hospital\'s internal newsletter, reminding HCWs of the importance of pertussis vaccination; email to the nurse´s teams leaders strengthening vaccine recommendations; lectures on pertussis and Tdap for physicians at the clinical meetings of the Obstetrics and Neonatology Clinics; on-site vaccination by mobile teams at the Obstetrics, Neonatology, and Anesthesiology Clinics. The vaccine coverage was evaluated at the end of each month until April-2016. A multivariate Poisson regression model with robust error variance was used to evaluate variables associated with Tdap vaccination. Prevalence ratios (PR) and their 95%CI were estimated. To evaluate the reasons for HCWs not to be vaccinated, those who have not received Tdap were called by phone and a standard questionnaire was applied. Results: Among 515 HCWs eligible for immunization, 59 professionals were not registered in the vaccination data system and were excluded because information about Tdap vaccine could not be achieved. The study included 456 HCWs. After the interventions, Tdap coverage raised from 2.9% to 41.2%. The vaccine coverage after each intervention was: 3.7% after a note on the hospital\'s internal newsletter; 10.5% after email to the nurse´s teams leaders strengthening vaccine recommendations; 16.2% after lectures on pertussis and Tdap for physicians at the clinical meetings of the Obstetrics and Neonatology Clinics; 27.9% after on-site vaccination by mobile teams at the Obstetrics Clinic; 40.6% after on-site vaccination at the Neonatology Clinic and 41.2% after on-site vaccination at the Anesthesiology Clinic. In the multiple analysis, occupation, working place and having received influenza vaccination in 2015 were independently associated to Tdap vaccination. Thirty-nine HCWs that have not received Tdap were contacted by phone: 90% of them claimed they did not know the vaccine recommendation. Conclusions: Knowledge about pertussis and the recommendation of vaccination are important to raise vaccine coverage between HCWs. Even knowing the cumulative effect of each strategy on vaccine coverage, HCWs vaccination in their workplaces seems to be the most effective strategy in raising coverage. The final Tdap coverage remains low and greater efforts are needed to increase it
55

The impact of pertussis toxin on T cell functions / Effet de la toxine pertussique sur les fonctions de cellule T

Koo, Yoon 15 February 2019 (has links)
La toxine pertussique (PTX) est une exotoxine produite uniquement par Bordetella pertussis, un pathogène de la coqueluche. Les effets de la toxine au cours d'une infection bactérienne sont bien connus, et sont pour la plupart liés à son activité ADP-ribosyltransférase qui cible les GPCRs. Or, la PTX est un antigène majeur permettant d’établir une réponse immunitaire contre B. pertussis ce qui en fait donc un composant principal de tous les vaccins anti-coqueluche actuels. De nombreux travaux sur la PTX concernent ses mécanismes moléculaires et son rôle durant la phase d'infection. Mais, il y a un manque d'information sur le rôle immunogène de la PTX.En utilisant un modèle d'infection intranasale par B. pertussis, nous avons constaté que la génération de lymphocytes T CD4 mémoires résidant (Trm) dans les poumons dépendait de l'exposition à la PTX. La toxine pertussique est couramment utilisée pour inhiber la réponse aux chimiokines, dans l'étude de la migration des cellules T. Etant donné que la plupart des récepteurs aux chimiokines sont des GPCRs, la mobilité de nombreuses cellules immunitaires, y compris les cellules T, est facilement affectée par la PTX. La migration des cellules T est un phénomène sophistiqué régulé spatio-temporellement. Nos résultats démontrent que la PTX n’affecte pas les étapes de la migration dépendantes des intégrines lorsque les cellules T sont activées.Ce travail s’intéresse à l'impact de la PTX sur la biologie des cellules T en étudiant son rôle dans la réponse immunitaire adaptative in vivo, dans un modèle animal d'infection et son impact sur la migration des lymphocytes T in vitro. / Pertussis toxin (PTX) is an exotoxin uniquely produced from Bordetella pertussis, a human respiratory tract pathogen causing pertussis disease, also known as whooping cough. The toxin is well described its virulence effects during bacterial infection. Most of these effects are due to ADP-ribosyltransferase activity of the molecule that targets G-protein coupled receptors (GPCR). On the other hand, PTX is an important antigen that provides protection against pertussis disease and a major component of all current pertussis vaccines. There are numerous literatures on PTX about its molecular mechanisms and its role during infection phase. Instead, lack of information on how PTX contributes host’s adaptive immunity has incurred confusion in understanding the immunogenic role of PTX. With intranasal infection model of B. pertussis, we detected the generation of CD4 lung-resident memory T cells (Trm) were depending on PTX exposure. For T cell migration study, PTX is being used to inhibit chemokine response. Because most of chemokine receptors are GPCR, the motility of many immune cells including T cells is easily affected by PTX. T cell migration is a sophisticate phenomenon regulated space-temporally. The results demonstrated, once T cells become activated and effector, are less influenced than inactivated T cells.This thesis reports the impact of PTX on T cells in two parts; 1) Role of PTX in adaptive immune response by in vivo infection system and 2) Influence of PTX on T cell motility by in vitro assays.
56

Signalizace adenylátcyklázového toxinu bakterie Bordetella pertussis v makrofázích. / Signalization of adenylate cyclase toxin of Bordetella pertussis in macrophages.

Černý, Ondřej January 2010 (has links)
Adenylate cyclase toxin (CyaA) is a key virulence factor of Bordetella pertussis, the causative agent of whooping cough. The toxin targets primarily myeloid phagocytes expressing CD11b/CD18 (αMβ2, CR3, Mac-1) and by elevation of cytosolic cAMP levels it paralyses their macropinocytic and opsono-phagocytic functions. Here, we dissected the cAMP-regulated pathway responsible for the block of macrophage macropinocytosis and characterized the capacity of CyaA-treated macrophages to shut- down Akt (protein kinase B, PKB) signaling; that controls nitric oxide (NO) production by macrophages. By using specific activators of protein kinase A (PKA) and for the exchange protein activated by cAMP (Epac), we show that activation of the cAMP effector Epac inhibits macropinocytosis in macrophages. Moreover, upon transfection of macrophages by the constitutively active and dominant negative variants of a downstream effector of Epac, the small GTPase Rap1, inhibition or upregulation of macrophage macropinocytosis was observed, respectively. It was reported previously that the Epac/Rap1 pathway regulates activity of tyrosin phosphatase SHP-1 as well as of protein phosphatase 2 A (PP2A). We show that inhibition of both tyrosin phosphatases and PP2A interferes with CyaA-mediated block of macropinocytosis. These...
57

Effet des saisons et de la malnutrition sur l’immunité des enfants sénégalais dans le cadre du programme vaccinal de l’OMS / Seasonal and nutritional modulation of children's immune response to vaccines in the frame of the Expanded Program on Immunization of the WHO

Gaayeb, Lobna 14 December 2012 (has links)
La réponse immunitaire, qu’elle soit générée suite à un contact naturel avec un agent infectieux ou après l’administration d’un vaccin, est sujette à des variations qui peuvent être dues à des facteurs environnementaux tels que les infections ou la malnutrition.Au cours de ce travail, nous avons étudié par une approche épidémiologique, l’influence des variations saisonnières et de la malnutrition sur la réponse immunitaire vis-à-vis de vaccins administrés aux enfants avant l’âge d’un an dans le cadre du Programme Elargi de Vaccination de l’Organisation Mondiale de la Santé (coqueluche, tétanos, diphtérie, tuberculose).Une étude longitudinale multidisciplinaire de terrain a été menée au nord du Sénégal, dans 5 villages de la vallée du Grand Fleuve, sur une cohorte de 410 enfants âgés de 1 à 9 ans. Des visites ont été réalisées dans l’ensemble des villages, à différents moments de l’année, englobant des périodes de saisons sèches et de saisons humides, afin de collecter des données parasitologiques, cliniques et anthropométriques, ainsi que des échantillons sérologiques. Dans le cadre de la santé publique, cette étude a permis d’apporter des données régionales sur la couverture vaccinale, la prévalence du paludisme et de l’état nutritionnel des enfants.La réponse immune à la coqueluche a été mesurée par le dosage d’anticorps dirigés contre la toxine de la coqueluche et l’hémagglutinine filamenteuse, deux antigènes de la bactérie Bordetella pertussis, l’agent principal de la coqueluche. Nos résultats concernant la réponse humorale à ces antigènes indiquent des variations du taux d’anticorps en fonction de l’âge des enfants ainsi que de leur village de résidence. La séroprévalence à B. pertussis a révélé la circulation endémique de la bactérie dans certains villages avec l’apparition d’un pic épidémique dans l’un d’entre eux. De plus, nos analyses suggèrent que la malnutrition est associée à une diminution de la réponse humorale aux antigènes de la coqueluche et que le retard de croissance influe sur la séroconversion vis-à-vis de cette infection bactérienne. Par ailleurs, le retard de croissance semble diminuer la capacité des cellules immunitaires des enfants à produire de l’interféron gamma, une cytokine clé intervenant dans la défense contre les infections, en réponse à des antigènes vaccinaux. Les conséquences à plus long terme de la malnutrition chronique infantile sur le maintien ou le développement des réponses immunes chez ces enfants lorsqu’ils seront plus âgés demeurent un point important à étudier.Mots-clés : anticorps, vaccination, coqueluche, Bordetella, malnutrition, Sénégal / Immune response, whether generated as a result of natural contact with an infectious agent or after the administration of a vaccine, is subject to changes, which may be due to environmental factors such as infections or malnutrition.In this work, we used an epidemiological approach to study the influence of seasonal variations and malnutrition on the immune response to vaccines administered to children before the age of one, in the frame of the Expanded Programme on Immunization set up by the World Health Organization (whooping cough, tetanus, diphtheria, tuberculosis).A longitudinal multidisciplinary study was conducted in northern Senegal in 5 villages of the Great River valley, on a cohort of 410 children aged 1 to 9. Visits were conducted in all villages at different times of the year, including periods of the dry season and wet season, to collect parasitological, clinical and anthropometric data, as well as serological samples. In the context of public health, this study provides regional data on immunization coverage, malaria prevalence, and nutritional status of children.
58

Computational models for the study of responses to infections / Bioinformatische Modelle zur Analyse der Immunantwort auf Infektionen

Thakar, Juilee January 2006 (has links) (PDF)
In diesem Jahrhundert haben neue experimentelle Techniken und Computer-Verfahren enorme Mengen an Information erzeugt, die bereits viele biologische Rätsel enthüllt haben. Doch die Komplexität biologischer Systeme wirft immer weitere neue Fragen auf. Um ein System zu verstehen, bestand der Hauptansatz bis jetzt darin, es in Komponenten zu zerlegen, die untersucht werden können. Ein neues Paradigma verknüpft die einzelnen Informationsteile, um sie auf globaler Ebene verstehen zu können. In der vorgelegten Doktorarbeit habe ich deshalb versucht, infektiöse Krankheiten mit globalen Methoden („Systembiologie“) bioinformatisch zu untersuchen. Im ersten Teil wird der Apoptose-Signalweg analysiert. Apoptose (Programmierter Zelltod) wird bei verschiedenen Infektionen, zum Beispiel bei Viruserkrankungen, als Abwehrmaßnahme eingesetzt. Die Interaktionen zwischen Proteinen, die ‚death’ Domänen beinhalten, wurden untersucht, um folgende Fragen zu klären: i) wie wird die Spezifität der Interaktionen erzielt? –sie wird durch Adapter erreicht, ii) wie werden Proliferation/ Überlebenssignale während der Aktivierung der Apoptose eingeleitet? – wir fanden Hinweise für eine entscheidende Rolle des RIP Proteins (Rezeptor-Interagierende Serine/Threonine-Proteinkinase 1). Das Modell erlaubte uns, die Interaktions-Oberflächen von RIP vorherzusagen. Der Signalweg wurde anschließend auf globaler Ebene mit Simulationen für verschiedene Zeitpunkte analysiert, um die Evolution der Aktivatoren und Inhibitoren des Signalwegs und seine Struktur besser zu verstehen. Weiterhin wird die Signalverarbeitung für Apoptosis-Signalwege in der Maus detailliert modelliert, um den Konzentrationsverlauf der Effektor-Kaspasen vorherzusagen. Weitere experimentelle Messungen von Kaspase-3 und die Überlebenskurven von Zellen bestätigen das Modell. Der zweite Teil der Resultate konzentriert sich auf das Phagosom, eine Organelle, die eine entscheidende Rolle bei der Eliminierung von Krankheitserregern spielt. Dies wird am Beispiel von M. tuberculosis veranschaulicht. Die Fragestellung wird wiederum in zwei Aspekten behandelt: i) Um die Prozesse, die durch M. tuberculosis inhibiert werden zu verstehen, haben wir uns auf das Phospholipid-Netzwerk konzentriert, das bei der Unterdrückung oder Aktivierung der Aktin-Polymerisation eine große Rolle spielt. Wir haben für diese Netzwerkanalyse eine Simulation für verschiedene Zeitpunkte ähnlich wie in Teil eins angewandt. ii) Es wird vermutet, dass Aktin-Polymere bei der Fusion des Phagosoms mit dem Lysosom eine Rolle spielen. Um diese Hypothese zu untersuchen, wurde ein in silico Modell von uns entwickelt. Wir fanden heraus, dass in der Anwesenheit von Aktin-Polymeren die Suchzeit für das Lysosom um das Fünffache reduziert wurde. Weiterhin wurden die Effekte der Länge der Aktin-Polymere, die Größe der Lysosomen sowie der Phagosomen und etliche andere Modellparameter analysiert. Nach der Untersuchung eines Signalwegs und einer Organelle führte der nächste Schritt zur Untersuchung eines komplexen biologischen Systems der Infektabwehr. Dies wurde am Beispiel der Wirt-Pathogen Interaktion bei Bordetella pertussis und Bordetella bronchiseptica dargestellt. Die geringe Menge verfügbarer quantitativer Daten war der ausschlaggebende Faktor bei unserer Modellwahl. Für die dynamische Simulation wurde ein selbst entwickeltes Bool’sches Modell verwendet. Die Ergebnisse sagen wichtige Faktoren bei der Pathologie von Bordetellen hervor, besonders die Bedeutung der Th1 assoziierten Antworten und dagegen nicht der Th2 assoziierten Antworten für die Eliminierung des Pathogens. Einige der quantitativen Vorhersagen wurden durch Experimente wie die Untersuchung des Verlaufs einer Infektion in verschiedenen Mutanten und Wildtyp-Mäusen überprüft. Die begrenzte Verfügbarkeit kinetischer Daten war der kritische Faktor bei der Auswahl der computer-gestützten Modelle. Der Erfolg unserer Modelle konnte durch den Vergleich mit experimentellen Beobachtungen belegt werden. Die vergleichenden Modelle in Kapitel 6 und 9 können zur Untersuchung neuer Wirt-Pathogen Interaktionen verwendet werden. Beispielsweise führt in Kapitel 6 die Analyse von Inhibitoren und inhibitorischer Signalwege aus drei Organismen zur Identifikation wichtiger regulatorischer Zentren in komplexen Organismen und in Kapitel 9 ermöglicht die Identifikation von drei Phasen in B. bronchiseptica und der Inhibition von IFN-γ durch den Faktor TTSS die Untersuchung ähnlicher Phasen und die Inhibition von IFN-γ in B. pertussis. Eine weitere wichtige Bedeutung bekommen diese Modelle durch die mögliche Identifikation neuer, essentieller Komponenten in Wirt-Pathogen Interaktionen. In silico Modelle der Effekte von Deletionen zeigen solche Komponenten auf, die anschließend durch experimentelle Mutationen weiter untersucht werden können. / In this century new experimental and computational techniques are adding an enormous amount of information, revealing many biological mysteries. The complexities of biological systems still broach new questions. Till now the main approach to understand a system has been to divide it in components that can be studied. The upcoming new paradigm is to combine the pieces of information in order to understand it at a global level. In the present thesis we have tried to study infectious diseases with such a global ‘Systems Biology’ approach. In the first part the apoptosis pathway is analyzed. Apoptosis (Programmed cell death) is used as a counter measure in different infections, for example viral infections. The interactions between death domain containing proteins are studied to address the following questions: i) How specificity is maintained - showing that it is induced through adaptors, ii) how proliferation/ survival signals are induced during activation of apoptosis – suggesting the pivotal role of RIP. The model also allowed us to detect new possible interacting surfaces. The pathway is then studied at a global level in a time step simulation to understand the evolution of the topology of activators and inhibitors of the pathway. Signal processing is further modeled in detail for the apoptosis pathway in M. musculus to predict the concentration time course of effector caspases. Further, experimental measurements of caspase-3 and viability of cells validate the model. The second part focuses on the phagosome, an organelle which plays an essential role in removal of pathogens as exemplified by M. tuberculosis. Again the problem is addressed in two main sections: i) To understanding the processes that are inhibited by M. tuberculosis; we focused on the phospholipid network applying a time step simulation in section one, which plays an important role in inhibition or activation of actin polymerization on the phagosome membrane. ii) Furthermore, actin polymers are suggested to play a role in the fusion of the phagosome with lysosome. To check this hypothesis an in silico model was developed; we find that the search time is reduced by 5 fold in the presence of actin polymers. Further the effect of length of actin polymers, dimensions of lysosome, phagosome and other model parameter is analyzed. After studying a pathway and then an organelle, the next step was to move to the system. This was exemplified by the host pathogen interactions between Bordetella pertussis and Bordetella bronchiseptica. The limited availability of quantitative information was the crucial factor behind the choice of the model type. A Boolean model was developed which was used for a dynamic simulation. The results predict important factors playing a role in Bordetella pathology especially the importance of Th1 related responses and not Th2 related responses in the clearance of the pathogen. Some of the quantitative predictions have been counterchecked by experimental results such as the time course of infection in different mutants and wild type mice. All these computational models have been developed in presence of limited kinetic data. The success of these models has been validated by comparison with experimental observations. Comparative models studied in chapters 6 and 9 can be used to explore new host pathogen interactions. For example in chapter 6, the analysis of inhibitors and inhibitory paths in three organism leads to the identification of regulatory hotspots in complex organisms and in chapter 9 the identification of three phases in B. bronchiseptica and inhibition of IFN-γ by TTSS lead us to explore similar phases and inhibition of IFN-γ in B. pertussis. Further an important significance of these models is to identify new components playing an essential role in host-pathogen interactions. In silico deletions can point out such components which can be further analyzed by experimental mutations.
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Inzidenz und Schweregrad von Bordetella pertussis : Erkrankungen bei Kindern und Jugendlichen in Bayern 2007 - 2008: eine ICD-10 basierte Untersuchung aus 27 bayerischen Kinderkliniken / Incidence and severity of Bordetella pertussis : infections among children and adolescents hospitalized in Bavaria 2007 - 2008: an ICD-10 based research of 27 Bavarian children`s hospitals

Donner, Magdalena January 2014 (has links) (PDF)
Trotz deutlich zunehmender Durchimpfungsraten bei Kindern und Jugendlichen tritt Pertussis in Deutschland weiterhin als Ursache signifikanter Morbidität auf, v. a. bei ungeimpften Kindern und Säuglingen. Die Datenlage zur Pertussis-Epidemiologie ist vor allem in den alten Bundesländern aufgrund der bis 2013 fehlenden Meldepflicht sehr begrenzt. Das Ziel dieser Studie war die Ermittlung der Inzidenz und des Schweregrades von ICD-10-dokumentierten Bordetella pertussis-Hospitalisationen bei Kindern in Bayern. 27 (73%) von insgesamt 37 bayerischen Kinderkliniken beteiligten sich an der Surveillance-Studie. Sie führten eine Datenabfrage für im Jahr 2007 und 2008 stationär aufgenommene Kinder unter 17 Jahren mit einem ICD- 10-Code für Pertussis (A37.0 oder A37.9) als Haupt- oder Nebendiagnose bei Entlassung durch. Zu diesen Kindern wurden demographische Basisdaten sowie Jahr und Monat der Hospitalisation, Haupt- und alle Nebendiagnosen, Aufenthaltsdauer und Behandlung (OPS-Codes) erhoben. Im 2-Jahres-Zeitraum 2007/2008 wurden insgesamt 171 Fälle identifiziert (2007:109 Fälle; 2008: 62 Fälle), mit 0-17 gemeldeten Fällen pro Klinik. Mädchen waren mit 51% (n=88) etwas häufiger betroffen als Jungen. Der Altersmedian lag bei vier Monaten (IQR: 1-14 Monate); 121 (70.7%) Kinder waren Säuglinge <1 Jahr, 102 (59.6%) <6 Monate und 41 (24.0%) <2 Monate alt. Die jährliche Inzidenz bei Säuglingen <1 Jahr wurde auf 67/100.000 Hospitalisationen geschätzt, bei Säuglingen <2 Monate auf 22/100.000. Respiratorische Komplikationen einschließlich Pneumonien und Apnoen traten bei 31% (n=53) aller Kinder auf; von diesen waren 82% (n=39) <1 Jahr bzw. 44% (n=21) <2 Monate alt. Fünf Kinder (3%) mussten intensivstationär behandelt werden, davon waren 4 jünger als 4 Monate. Bei einem Säugling (0.6%) war ein Krampfanfall dokumentiert, kardio-respiratorische Komplikationen kamen bei 2% und Dehydratation bei 8% aller Kinder vor. Sowohl die Inzidenz der Hospitalisationen als auch die Komplikationsrate waren am höchsten bei Säuglingen <1 Jahr bzw. <2 Monaten. Die Ergebnisse belegen die Bedeutung der zeitgerechten Umsetzung der Impfempfehlung, d.h. den rechtzeitigen Start der Grundimmunisierung im Alter von 2, 3 und 4 Monaten. Auch die bereits 2004 empfohlene Impfung von Kontaktpersonen ist für die Prävention von Pertussis bei Säuglingen von hoher Wichtigkeit. Die bisher nicht allgemein empfohlene Impfung für Schwangere bzw. für Neugeborene könnte ggf. die Hospitalisationszahlen weiter senken; weitere Studien dazu werden dringend benötigt. / Despite high vaccination coverage among infants and adolescents, pertussis remains a reason for a high rate of morbidity and mortality, especially in unvaccinated infants. The data available on regard to pertussis epidemiology is very limited due to the fact that, until 2013, there was no reporting obligation for pertussis in the states of former West Germany. The aim of this study is to investigate the hospitalization rate and severity of ICD-10 documented Bordetella pertussis infections in Bavarian children. 27 (73%) of a total of 37 Bavarian children`s hospitals participated in the surveillance study. They carried out data retrieval for children under 17 years of age hospitalized in 2007 or 2008 with an ICD-10-pertussis-code (A37.0 or A37.9) as the primary or secondary diagnosis at discharge. The collected database included basic demographic data, year and month of hospital admission, all primary and secondary diagnoses, duration of hospital stay and treatment (OPS- and DRG-codes). From 2007 to 2008 a total of 171 cases were reported (2007: 109 cases; 2008: 62 cases), with 0-17 cases reported per hospital. At 51%, girls were more frequently affected than boys. The median age was 4 months (IQR: 1-14 months). 121 (70,7%) children were infants <1 year, 102 (59,6%) <6 months and 41 (24%) <2 months of age. The annual incidence for infants <1 year was estimated at 67 pertussis hospitalizations/100,000 children < 1 year, and for infants <2 months at 109 pertussis hospitalizations/100,000 children <2 months. Respiratory complications, including pneumonia and apnea, developed in 31% (n=53) of the children: whereby 82% (n=39) of them were <1 year old and 44% (n=21) <2 months of age. Five children (3%) required intensive care treatment, four of them were younger than 4 months of age. Convulsions were observed in one infant (0,6%). Further complications were cardio-respiratory complications (2%) and dehydration (8%). Both the incidence and complication rate were highest among children under 1 year of age and for infants under 2 months of age. The results prove the importance of timely implementation of vaccination recommendations i. e. the punctual beginning of basic immunization at the age of 2, 3 and 4 months. Furthermore, the vaccination of contact persons, which was recommended in 2004, is also extremely important for pertussis prevention in infants. Until now there has been no general recommendation for the vaccination of pregnant women or neonates as yet. However, these vaccinations could possibly reduce hospitalization rates even more; further studies are urgently required in this area.
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An Examination of the Socio-Demographic Characteristics Associated with Adult Vaccination Prevalence for Preventable Diseases in the United States

Mastrodomenico, Jessica 15 May 2010 (has links)
Background: An estimated 50,000 adults in the United States (U.S.) die each year from one of 10 vaccine preventable diseases. For those who survive vaccine preventable infections, health care costs and loss of income become more significant. While children in the U.S. aged 0-2 exhibit vaccine prevalence rates of almost 90%, some adult vaccine prevalence rates in the U.S. population are reported to be nearly 30-40% less than the goals set forth by Healthy People 2010. The purpose of this study was to examine the associations between socio-demographic characteristics of U.S. adults and adult vaccination prevalence for pneumococcal, hepatitis A, hepatitis B, tetanus, and pertussis. Methods: Data from the 2008 National Health Interview Survey were assessed examining various health indicators and characteristics of non-institutionalized adults and children. The sample was restricted to adults ≥18 years of age. Odds ratios were calculated and multivariate logistic regression was also conducted. P-values of Results: There were 21781 total observations; 19.3% received the pneumococcal vaccine, 9.4% received the hepatitis A vaccine, 27.2% received the hepatitis B vaccine, 55.1% received the tetanus vaccine, and 15.2% received the pertussis vaccine. Of the socio-demographic characteristics examined, age, health insurance, marital status, and education were significant for either all five or at least four of the vaccines included in this study. As one might expect those who reported health insurance and those who had a higher level of education usually had a higher likelihood of vaccine receipt as compared to those without health insurance and those with less than a high school education. Age associations varied due to age-related recommendations for certain vaccines such as pneumococcal (recommended for adults ≥65). Compared to the married population (referent), marital status results varied, but for reasons unclear. Whites, the referent group, were the most likely to be vaccinated as compared to Blacks, Hispanics/Latinos, and Asians. Hispanics/Latinos typically had the lowest likelihood of vaccination in this examination. Conclusions: This study further explores the impact of socio-demographic disparities on vaccination status and adds new information to the literature regarding adult vaccination rates for preventable diseases. While research exists related to strengthening interventions such as patient reminder systems, those who do not see the same health care providers on a regular basis remain at risk for lower vaccination prevalence. It is important to better understand the role of social determinants of health, specifically in terms of vaccinations. Future research is needed to further characterize the association of socio-demographic factors with receipt of optional vaccines in adults.

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