La tuberculose (TB) est encore aujourd’hui une cause majeure de morbidité et mortalité dans le monde. Sa maitrise a été rendue difficile par l’épidémie de VIH et la résistance au antituberculeux. La méningite tuberculose (MTB), est la forme la plus grave de TB et est un des indicateurs utilisés pour la politique vaccinale par le BCG. La multirésistance aux antituberculeux (MDR) qui pose des problèmes diagnostiques et thérapeutiques est surveillée depuis 1992 en France. En revanche, la mono-résistance à la Rifampicine (mono-RMP-R) qui représente une première étape vers la TB MDR est rarement étudiée et le devenir des malades est inconnu en France. Notre travail a été axé sur l’épidémiologie de la MTB et l’impact des modifications de stratégie vaccinale par le BCG. Nous avons pour cela utilisé deux systèmes de surveillance de la tuberculose en France : un réseau national de laboratoires coordonné par le centre national de référence des mycobactéries (CNR), et le système de la déclaration obligatoire (DO), coordonné par l’Institut de Veille Sanitaire (InVS). Nous avons également utilisé le réseau du CNR pour évaluer la monorésistance à la rifampicine dans la TB en France. Nous avons tout d’abord évalué le taux d’incidence de la tuberculose du système nerveux central à culture positive (TB SNC C+) en France en 2007 (année de modification de la politique vaccinale) et son évolution entre 1990 et 2007. En 2007, la TB SNC C+ représentait moins de 1% de tous les cas tuberculose à culture positive et son incidence était de 0,5/million d’habitants. La sensibilité du réseau du CNR était de 79,4%. Pour évaluer l’évolution de la TB SNC C+ entre 1990 et 2007, nous avons utilisé une sensibilité « moyenne » dérivée de la sensibilité du CNR pour l'année 2000 (75,6%) et celle pour l'année 2007 pour corriger le nombre de cas signalés dans chacune des 4 études (1990, 1995, 2000, 2007). Nous avons observé une diminution de 62% du nombre corrigé de TB SNC C+ en 17 ans (90 à 35 cas) et du taux d'incidence corrigé (de 1,6 à 0,55 cas par million d'habitants) (P < 0.001). Ensuite, nous avons mesuré l’impact des deux changements majeurs de la politique vaccinale par le BCG en 2006 (arrêt de la multipuncture) et 2007 (arrêt du BCG obligatoire), sur l’épidémiologie de la MTB chez les enfants <6 ans en France entre 2000 et 2011. Au total, 10 cas de MTB à culture positive et 17 cas de MTB possibles (culture négative ou inconnue) ont été identifiés, avec un taux d’incidence annuel variant de 0,16 à 0,66 cas/10 million habitants. En Ile de France où tous les enfants sont considérés « à risque » et donc devraient tous être vaccinés, ou dans les autres régions, où seuls les enfants à risque sont vaccinés depuis 2007, il n’existait aucune différence significative des taux d'incidence annuels pour chaque cohorte d’un an. Ces résultats renforcent la décision d'arrêter de la vaccination universelle par le BCG en 2007. Toutefois une surveillance étroite de la TB SNC dans les années à venir sera nécessaire pour évaluer l'impact long-terme de la nouvelle stratégie vaccinale. Finalement, nous avons mis en place par le biais du réseau des laboratoires du CNR une cohorte rétrospective des cas de TB mono-RMP-R diagnostiqués en France entre 2005 et 2010. Au total, 39 cas de TB mono-RMP-R (soit 0.12% des cas de TB) ont été recensés. Parmi tous ces patients, 19 cas (49%) avaient un antécédent de traitement de leur tuberculose, et 9 (23%) étaient infectés par le VIH. Les données sur le traitement et le devenir étaient disponibles pour 30 des 39 patients et seulement 20 (67%) ont été considérés guéris. Les traitements reçus tant en terme de drogues que de durée étaient hétérogènes. Ces résultats suggèrent qu’il faut améliorer la prise en charge des malades atteints de TB mono-RMP-R en France. / Tuberculosis (TB) remains a major cause of morbidity and mortality worldwide, partly because of drug resistance anf the HIV epidemics. Tuberculous meningitis (TBM) is the most severe form of the tuberculosis disease, and is one of the indicators used for the BCG vaccination policy. Multidrug resistant tuberculosis (MDR-TB), which poses diagnostic and therapeutic problems, has been monitored since 1992 in France. On the opposite, rifampicin mono-resistance (RMR) tuberculosis (TB) which represents a first step toward MDR-TB is rarely studied and the impact of rifampicin mono-resistance on patient’s outcome is unknown in France. Our work was focused on the epidemiology of MTB and the impact of changes in the BCG vaccination strategy. We used two systems implemented for the surveillance of TB in France: a nationwide laboratory network coordinated by the National Reference Centre (NRC) for Mycobacteria and Resistance of Mycobacteria to Anti-tuberculosis Drugs and the mandatory notification system of TB (MNS) coordinated by the National Institute for Public Health Surveillance (Institut de Veille Sanitaire, InVS). The NRC network was also used to evaluate Rifampicin mono-resistant tuberculosis in France. First, we assessed the incidence rate of culture-positive (C+) central nervous system tuberculosis (CNS TB) in France in 2007 (the year of the changing policy on BCG vaccination) and its time trend between 1990 and 2007. In 2007, CNS TB represented less than 1% of all culture-positive TB cases and its incidence was around 0.50 per million inhabitants. The 2007 sensitivity of the NRC was 79.4%. To assess the evolution of C+ CNS TB between 1990 and 2007, we used an average sensitivity derived from the 2000 sensitivity of the NRC (75.6%) and the sensitivity for the year 2007. The average sensitivity was used to correct the number of C+ CNS TB reported in four surveys (1990, 1995, 2000, 2007). There was a major decrease of 62% in the extrapolated number of C+ CNS TB in seventeen years (from 90 to 35 cases), and in the extrapolated incidence rate (from 1.6 to 0.55 cases per million inhabitants) (P < 0.001). Then, we measured the impact of two major changes in BCG vaccination policy in 2006 (disappearance of the multipuncture device for BCG) and 2007 (end of compulsory BCG vaccination) on the epidemiology of TBM in children under 6 years in France between 2000 and 2011. Overall, 10 culture-positive and 17 possible (negative-culture or unknown microbiological result) cases of TBM were identified, with an annual incidence rate varying from 0.16 to 0.66 cases / 10 million inhabitants. In Ile-de-France, where all children are considered “at risk” and therefore should all be vaccinated, and in the other regions where only at-risk children are considered for vaccination since 2007, no statistically significant differences in the annual incidences rates for each one-year age-group cohort could be observed. These results reinforce the 2007 decision to stop universal BCG vaccination. However, a close monitoring of CNS TB in the coming years will be needed to assess the long-term impact of the new vaccination policy. Finally, we built, through the NRC national network of laboratories, a retrospective cohort of RMR TB cases diagnosed between 2005 and 2010. A total of 39 cases with RMR TB were identified (0.12% of all TB culture positive cases). Among all patients, 19 (49%) had a previous history of TB treatment, and 9 (23%) were HIV-coinfected. Data about treatment and outcome were available for 30 of 39 patients and only 20 (67%) were considered as cured. Treatments received both in terms of drugs and duration were heterogeneous. These results suggest the need to improve the management of patients with RMR TB in France.

Les épidémies de méningite à méningocoque représentent un problème de santé publique majeur au Niger. L'objectif de la thèse est de contribuer à une meilleure compréhension de la dynamique spatio-temporelle des épidémies et des facteurs de risque, afin d'améliorer les stratégies de contrôle. Des méthodes statistiques d'épidémiologie spatiale sont appliquées aux données de surveillance de 2003 à 2010, à l'échelle des aires de santé.D'importantes caractéristiques de la distribution spatio-temporelle des cas sont d'abord mises en évidence par des méthodes d'autocorrélation spatiale et de scan spatial : faible étendue des agrégats spatio-temporels, hétérogénéité spatiale, variabilité inter-annuelle... L'analyse suggère que l'échelle des aires de santé pourrait être plus efficace pour la réponse aux épidémies.Un modèle explicatif hiérarchique bayésien est ensuite développé à l'échelle des aires de santé. Il suggère que la variabilité spatio-temporelle de l'incidence du méningocoque A résulte de variations dans l'intensité et la durée de facteurs climatiques, et est de plus impactée par des facteurs de contacts spatiaux. Enfin, un modèle prédictif est développé, basé sur les conditions climatiques, les interactions de voisinage et la précocité des cas, pour estimer le risque de survenue d'une épidémie localisée. Le système d'alerte ainsi élaboré pourrait améliorer la détection des épidémies et la vaccination réactive.Nos résultats offrent un nouvel éclairage sur les épidémies de méningite à méningocoque au Niger. Ils permettent de formuler des recommandations opérationnelles qui pourraient contribuer à l'élaboration de stratégies de contrôle et de prévention efficaces. / Epidemics of meningococcal meningitis are a major public health problem in Niger. The objective of the thesis is to contribute to a better understanding of the spatio-temporal dynamics of these epidemics and their risk factors, in order to improve control strategies. Statistical methods of spatial epidemiology are applied to surveillance data from 2003 to 2010, at the scale of health centre catchment areas (HCCAs).First, important features of the spatio-temporal distribution of cases are highlighted by methods of spatial autocorrelation and spatial scan: low extent of the spatio-temporal clusters, spatial heterogeneity, inter-annual variability… The analysis suggests that the HCCA scale could be more efficient for epidemic response. An explanatory Bayesian hierarchical model is then developed at the HCCA level. The model suggests that the spatio-temporal variability of meningococcal A incidence results from variations in the intensity or duration of climatic factors, and is further impacted by factors of spatial contacts.Finally, a predictive model is developed, based on climatic conditions, neighbourhood interactions and early cases, in order to estimate the risk of occurrence of a localized epidemic. The early warning system thus formulated could improve outbreak detection and reactive vaccination. Our results bring new insights into the meningococcal meningitis epidemics in Niger. They allow the formulation of operational recommendations that could contribute to the elaboration of more effective strategies for control and prevention of epidemics.

Publicación a texto completo no autorizada por el autor / El documento digital no refiere asesor / Describe el uso de la punción lumbar en la convulsión febril en pacientes de 6 a 18 meses de edad del Instituto Nacional de Salud del Niño durante el periodo 2008 a 2009. Se realizó un estudio observacional, retrospectivo, transversal, de 65 niños de 6 meses a 18 meses de edad con convulsión febril, en el periodo que correspondió al estudio. Hubo 29 varones (44.6 %), y 36 mujeres (55.4 %). La media de la edad global de los pacientes en estudio fue de 10.6+/- 3.7 meses, siendo la mínima de 6 meses y la máxima de 18 meses. El 63.1 % de los pacientes tuvieron entre 6 a 12 meses. Hubo una mayor frecuencia de convulsión generalizada en el 90.8 % de los casos. En el 84.6 % de los casos duró menos de 15 minutos, y en el 15.4 % duro menos de 15 minutos. Hubo recurrencia de la convulsión en el 58.5%. Hubo una mayor frecuencia de foco respiratorio en el 76.9 %, seguido del foco gastrointestinal (15.4%). El 55.4% de los pacientes tuvieron temperatura menor de 38°C. El 13.8% de los casos tuvieron antecedente familiar de convulsión. Hubo una mayor frecuencia de convulsión febril compleja en el 78.5 % de los casos. El riesgo de meningitis en los pacientes con convulsión febril a los cuales se les realiza punción lumbar es bajo o nulo. Hay mayor frecuencia de convulsión febril en mujeres entre los 6 a 12 meses. No hubo ningún caso de convulsión febril por meningitis aguda. / Trabajo de investigación

Bacterial meningitis in dogs and cats is a rare disease associated with a high lethality rate. The spectrum of causative bacteria includes a diverse set of gram positive, gram negative and anaerobic species. Currently, no veterinary medicinal product is approved for this indication in these species in Europe. The objective of this review was to collect the available pharmacokinetic data for antibiotics approved in dogs and cats to enable a preliminary analysis of their potential effectiveness for the treatment of bacterial meningitis. This analysis yielded data for 13 different antibiotics in dogs and two in cats. Additionally, data about frequently recommended cephalosporines not approved in dogs and cats were included. The collected data was used to assess the potential of the respective antibiotics to attain certain simple pharmacokinetic-pharmacodynamic (PK-PD) indexes in the cerebrospinal fluid (CSF). A more sophisticated investigation using modern methods was not possible due to the limited data available. For this purpose, data about the sensitivity of four bacterial species commonly associated with meningitis in dogs and cats to these antibiotics were included. The analysis provided evidence for the potential effectiveness of ampicillin, doxycycline, enrofloxacin, ceftriaxone and cefoxitin against bacteria frequently detected in bacterial meningitis in dogs. Data were not available or insufficient for the assessment of several antibiotics, including frequently recommended substances like metronidazole and trimethoprimsulphonamide. Little evidence is available for the use of antibiotics in cats afflicted with this disease, highlighting the need for further research to obtain data for evidence based therapeutic recommendations.

Neisseria meningitidis (N. meningitidis) is an obligate human pathogen which causes live-threatening sepsis and meningitis. The fatality rate after meningococcal infection is high and surviving patients often suffer from severe sequelae. To cause meningitis, N. meningitidis must overcome the endothelium of the blood-brain barrier. The bacterium achieves this through the interaction with endothelial surface receptors leading to alternations of the cellular metabolism and signaling, which lastly results in cellular uptake and barrier traversal of N. meningitidis. Sphingosine 1-phosphate (S1P) is a lipid mediator that belongs to the class of sphingolipids and regulates the integrity of the blood-brain barrier through the interaction with its cognate receptors S1P receptors 1-3 (S1PR1-3). In this study, high performance liquid chromatography coupled with mass spectrometry (LC-MS/MS) was used to generate a time-resolved picture of the sphingolipid metabolism in a brain endothelial cell line (hCMEC/D3) upon meningococcal infection. Among various changes, S1P was elevated in the cellular compartment as well as in the supernatant of infected hCMEC/D3s. Analysis of mRNA expression in infected hCMEC/D3s with quantitative real-time polymerase chain reaction (RT-qPCR) revealed that the increase in S1P could be attributed to the enhanced expression of the S1P-generating enzyme sphingosine kinase 1 (SphK1). Antibody-based detection of SphK1 protein or phosphorylation at SphK1 residue Serine 225 in hCMEC/D3 plasma membrane fractions via Western Blot revealed that N. meningitidis also induced SphK1 phospho-activation and recruitment to the plasma membrane. Importantly, recruitment of SphK1 to the plasma membrane increases the probability of substrate encounter, thus elevating SphK activity. Enhanced SphK activity was also reflected on a functional level, as detected by a commercially available ATP depletion assay used for measuring the enzymatic activity of SphK. Infection of hCMEC/D3 cells with pilus-deficient mutants resulted in a lower SphK activation compared to the N. meningitidis wild type strain. hCMEC/D3 treatment with pilus-enriched protein fractions showed SphK activation similar to the infection with living bacteria and could be ascribed to pilus interaction with the membrane-proximal domain of cellular surface receptor CD147. Inhibition of SphK1 or SphK2 through pre-treatment with specific inhibitors or RNA interference reduced uptake of N. meningitidis into hCMEC/D3 cells, as measured with Gentamicin protection assays. Released S1P induced the phospho-activation of epidermal growth factor receptor (EGFR) via S1PR2 activation, whose expression was also increasing during infection. Furthermore, S1PR2 blockage had a preventive effect on bacterial invasion into hCMEC/D3 cells. On the contrary, activation of S1PR1+3 also reduced bacterial uptake, indicating an opposing regulatory role of S1PR1+3 and S1PR2 during N. meningitidis uptake. Moreover, SphK2 inhibition prevented inflammatory cytokine expression as well as release of interleukin-8 after N. meningitidis infection. Taken together, this study demonstrates the central role of S1P and its cognate receptors S1PR1-3 in the pathophysiology of meningococcal meningitis. / Neisseria meningitidis (N. meningitidis) ist ein obligat humanpathogenes Bakterium, welches lebensbedrohliche Sepsis und Meningitis auslöst. Die Todesrate nach einer Meningokokkeninfektion ist hoch und überlebende Patienten leiden oft unter gravierenden Folgeschäden. N. meningitidis muss zuerst das Endothel der Blut-Hirn-Schranke überwinden, um Meningitis auslösen zu können. Das Bakterium erzielt dies durch die Interaktion mit endothelialen Rezeptoren, welche den zellulären Metabolismus und die zellulären Signalwege beeinflusst und letztlich zur zellulären Aufnahme von N. meningitidis und zur Überwindung der Barriere führt. Sphingosine 1-phosphat (S1P) ist ein Lipidmediator, der zur Klasse der Sphingolipide gehört und die Integrität der Blut-Hirn-Schranke durch die Interaktion mit den zugehörigen S1P Rezeptoren 1-3 (S1PR1-3s) beeinflusst. In dieser Arbeit wurde Hochleistungsflüssigkeitschromatographie-gekoppelte Massenspektrometrie (LC-MS/MS) genutzt, um ein zeitlich aufgelöstes Bild des Sphingolipidmetabolismus in einer Hinendothelzelllinie (hCMEC/D3) nach Meningokokkeninfektion zu generieren. Neben zahlreichen Veränderungen zeigte sich ein Anstieg von S1P im zellulären Kompartiment und im Überstand von infizierten hCMEC/D3 Zellen. Die Analyse der mRNA Expression in infizierten hCMEC/D3 Zellen mittels quantitativer Echtzeit-Polymerase-Kettenreaktion (RT-qPCR) offenbarte, dass der Anstieg von S1P auf eine erhöhte Expression der S1P-bildenden Sphingosinkinase 1 (SphK1) zurückzuführen war. Die ntikörperbasierte Detektion des Proteins SphK1 oder dessen Phosphorylierung an Serin 225 in den Membranfraktionen von hCMEC/D3 Zellen mittels Western Blot zeigte, dass N. meningitidis außerdem die Phospho-Aktivierung und Membrantranslokation von SphK1 induzierte. Die Plasmamembrantranslokation von SphK1 erhöht die Wahrscheinlichkeit auf das Substrat Sphingosine zu treffen und verstärkt somit die SphK-Aktivität. Die erhöhte SphK-Aktivität zeigte sich auch auf funktioneller Ebene, wie mittels eines ATP-Verbrauchs-Assays zur Messung der SphK-Aktivität nachgewiesen werden konnte. Die Infektion von hCMEC/D3 Zellen mit Pilus-defizienten Mutanten resultierte in einer geringeren SphK-Aktivierung im Vergleich zum Wildtypstamm. Die Behandlung von hCMEC/D3 Zellen mit Pilus-aufgereinigten Fraktionen zeigte eine SphK-Aktivierung, die mit der Aktivierung durch lebende Bakterien vergleichbar war und der Interaktion des Pilus mit der membranproximalen Domäne des zellulären Oberflächenrezeptors CD147 zugeordnet werden konnte. Die Inhibition von SphK1 und SphK2 durch die Vorbehandlung mit spezifischen Inhibitoren oder RNA-Interferenz reduzierte die Aufnahme von N. meningitidis in hCMEC/D3 Zellen, wie mittels Gentamicin Protection Assay nachgewiesen wurde. Das freigesetzte S1P induzierte die Phospho-Aktivierung des epidermalen Wachstumsfaktorrezeptors (EGFR) durch die Aktivierung von S1PR2, welcher während der Infektion vermehrt exprimiert wurde. Die Blockierung von S1PR2 hatte einen präventiven Effekt auf die bakterielle Invasion in hCMEC/D3 Zellen. Im Gegenzug reduzierte die Aktivierung von S1PR1+3 ebenfalls die bakterielle Aufnahme, was auf eine gegensätzliche regulatorische Rolle von S1PR1+3 und S1PR2 während der Aufnahme von N. meningitidis in hCMEC/D3 Zellen hindeutet. Darüber hinaus verhinderte die Inhibition von SphK2 die Expression von inflammatorischen Cytokinen sowie die Freisetzung von Interleukin-8 nach Infektion mit N. meningitidis. Zusammenfassend zeigt diese Arbeit die zentrale Rolle von S1P und den zugehörigen Rezeptoren S1PR1-3 in der Pathophysiologie der durch Meningokokken ausgelösten Meningitis.

Introdução: O implante auditivo de tronco encefálico (ABI) é indicado para pacientes com perda auditiva neurossensorial severa a profunda quando há impossibilidade de realização do implante coclear. Em pacientes com surdez por meningite e ossificação coclear total bilateral, o ABI é a opção para a reabilitação auditiva. Objetivos: O estudo tem por objetivo avaliar a contribuição do ABI para os limiares audiométricos e para a percepção de fala após no mínimo 12 meses de uso em pacientes com ossificação coclear total por surdez pós-meningite, bem como descrever as complicações do procedimento. Material e métodos: Dez pacientes com surdez pósmeningite foram submetidos ao ABI por via retrolabiríntica ampliada em um centro terciário de assistência e ensino. Todos os pacientes foram operados pela mesma equipe cirúrgica e a avaliação audiológica foi realizada pelo mesmo fonoaudiólogo. Foram realizados audiometria tonal e testes de percepção de fala no pré-operatório e no mínimo 12 meses após a ativação do implante. Foram descritas as complicações associadas ao procedimento. Resultados: Oito de dez pacientes implantados permaneceram usuários. Dois pacientes não apresentaram respostas auditivas e abandonaram o seguimento. Os oito pacientes apresentaram melhora estatisticamente significativa nos limiares audiométricos, bem como nos testes de discriminação de palavras e vogais comparando pré e pós-operatório com média de seguimento de 3,3 anos. Em dois pacientes, a discriminação de sentenças em formato fechado somente no modo auditivo foi de 30% e 40%. Todos os oito usuários referiram benefício com o uso do ABI. Não houve complicações relacionadas ao procedimento. Conclusão: O ABI via retrolabiríntica ampliada é uma opção terapêutica segura para pacientes com surdez pós-meningite e com presença de ossificação coclear total bilateral, contribuindo para melhora nos limiares audiométricos e nos testes de percepção de fala. Embora a melhora nos testes audiológicos seja inferior à do implante coclear, a maioria dos pacientes do estudo usa o ABI diariamente por um período superior a 8 horas e refere benefício em seu cotidiano / Introduction: The Auditory Brainstem Implant (ABI) is an option to auditory restoration in patients with severe to profound sensorineural hearing loss who cannot be fitted with a cochlear implant. This is the only option in patients with post meningitis hearing loss presenting with bilateral total cochlear ossification. Objectives: The main objective of the study is to evaluate the hearing contribution in audiometry and speech perception tests at least 12 months after ABI implantation in patients with post-meningitis profound hearing loss. The complications of the procedure were also described. Materials and Methods: Ten patients with post-meningitis hearing loss went an ABI through extended retrolabyrinthine approach in a tertiary center by the same surgeons. The same audiologist was responsible for audiological follow-up. Tonal audiometry and speech perception tests were made before and at least 12 months after the ABI activation. The procedure complications were described for all patients. Results: Eight of ten patients became ABI users. Two patients had no auditory response and abandoned the treatment. Eight users showed benefit in tonal audiometry, word and vowels perception tests after an average follow up of 3.3 years. Two patients were able to recognize 30 and 40% of closed sentences without lip reading. There were no complications due to the ABI procedure. Conclusion: The extended retrolabyrinthine approach for the ABI is a safe surgical option for patients with post-meningitis hearing loss and totally ossified cochleae. It contributes to hearing performance in audiometry and speech perception tests. Even though the ABI results are poorer than the cochlear implants, in this study the majority of patients use their ABI more than eight hours a day and report benefits in daily activities

Die bakterielle Meningitis ist trotz der Anwendung modernster Antibiotika mit einer hohen Letalität und neurologischen Spätkomplikationen verbunden. Ein entscheidendes Ereignis ist dabei der Zusammenbruch der Blut-Hirn-Schranke (BHS). Die genauen Mechanismen, die zu ihrer Schädigung führen, sind bis heute unklar. In dieser Arbeit wurde untersucht, ob lebende Pneumokokken in einem Zellkulturmodell der BHS zu einer apoptotischen Zellschädigung von zerebralen Endothelzellen, als wichtigstem zellulären Bestandteil der BHS, führen und damit zu ihrer strukturellen Schädigung beitragen. Mittels verschiedener Detektionsmethoden (TUNEL, Fluoreszenzmikroskopie, Elektronenmikroskopie) konnte nachgewiesen werden, daß Streptococcus pneumoniae zu einem apoptotischen endothelialen Zelltod führt. Eine Beteiligung von Caspasen konnte weder mit direkter Aktivitätsmessung noch mittels Inhibitionsexperimenten oder dem Nachweis von Caspase-spezifischen Substraten gezeigt werden. Insgesamt sind die Morphologie der Zellkerne und die spezifische Degradation der endothelialen DNS hinweisend für einen Apoptosis-Inducing-Factor-vermittelten Zelltod ohne Caspasenbeteiligung. Diese Form des Zelltodes ist bereits in anderen Zellmodellen, bisher jedoch nicht bei zerebralen Endothelzellen beschrieben worden. Auf Seiten des Bakteriums konnten Wasserstoffperoxid und Pneumolysin als Auslöser der Apoptose identifiziert werden. Die zytotoxische Potenz des Pneumolysins ist dabei an dessen Poren-formende Aktivität gebunden. Die Ergebnisse sind von potentieller klinischer Relevanz, da es bei einer Bakteriämie und während der Invasion der Pneumokokken in das ZNS zu einem direkten Kontakt zwischen Bakterien und zerebralen Endothelzellen kommt und sich daraus eine Möglichkeit zur Entwicklung adjuvanter Therapien ergeben könnte. / Despite sufficient antibiotic treatment, pneumococcal meningitis has remained a disease associated with high mortality and neurological sequelae. The disruption of the blood brain barrier (BBB) is regarded a key event in the initial phase of pneumococcal meningitis. However, the exact molecular mechanisms involved in this process are still unknown. The aim of this study was to determine if living pneumococci are able to induce apoptosis in cerebral endothelial cells - the main cellular component of BBB - and therefore might contribute to its damage. Using several different detection methods (TUNEL, fluorescence and electron microscopy), induction of apoptotic cell death of endothelial cells by pneumococci could be verified. An accompanying activation of caspases was not detectable, despite the use of specific detection techniques such as inhibition experiments, direct enzyme measurements and detection of caspase-specific protein cleavage. These results as well as the specific nuclear morphology and degradation of endothelial DNA suggest an involvement of the mitochondrial protein Apoptosis inducing factor (AIF). This is the first time this specific form of apoptotic, AIF-driven cell death has been described to be engaged in endothelial cells. On the part of the bacterium, pneumolysin and hydrogen peroxide were identified as the two main inducers of apoptosis. The cytotoxic potency of pneumolysin is related to its pore-forming activity. These results are of clinical relevance since pneumococci are known to reside in close proximity to cerebral endothelial cells during bacteriemia and their entry into the CNS. These findings could contribute to the development of adjuvant treatment of bacterial meningitis.

Toll-like Rezeptoren (TLR) und Nod-like Rezeptoren (NLR) sind Muster-erkennende Rezeptoren des angeborenen Immunsystems, die bakterielle Zellwandbestandteile erkennen können. Interleukin (IL)-1beta ist ein streng reguliertes Zytokin. Durch eine erste Stimulation wird der TLR-Rezeptor ausgelöst und führt zur Expression des Vorläuferproteins proIL-1beta. Durch einen zweiten Stimulus wird ein zytoplasmatischer NLR-Rezeptor zur Caspase1-Aktivierung angeregt. Dies führt zur post-translationalen Reifung von proIL-1beta zu reifem IL-1beta und zur Aktivierung weiterer Mechanismen der Pathogen-Eliminierung während einer bakteriellen Meningitis. Im ersten Teil dieser Arbeit wurde die synergistische Beziehung zwischen TLRs und NOD2 in Bezug auf die IL-1beta-Sekretion in Astrozyten und Mikroglia untersucht. Primäre murine WT-Astrozyten und eine humane Zelllinie, die mit Lipopolysaccharid (LPS) oder Lipopeptid sowie Muramyldipeptid (MDP) stimuliert wurden, zeigten signfikant erhöhte IL-1beta-Werte. IL-1beta war in NOD2-/- Astrozyten nicht erhöht. NOD2 trägt demnach als MDP-ausgelöster Rezeptor in Astrozyten, vermutlich zusammen mit dem Inflammasom-Komplex, zur Caspase-1-Aktivierung bei. In Mikrogliazellen lässt sich der bei Astrozyten gezeigte Effekt nicht reproduzieren. Zum ersten Mal wurde gezeigt, dass die TLR-abhängige IL-1beta-Antwort durch NOD2-Beteiligung in murinen und humanen Astrozyten synergistisch erhöht wird. In einem weiteren Versuchsteil wurde in primären murinen Peritonealmakrophagen von adulten Mäusen der TLR/NLR-Synergismus untersucht. Es stellte sich überraschenderweise heraus, dass weibliche NOD2-/- Mäuse zu einer synergistisch erhöhten IL-1beta-Sekretion fähig waren. SiRNA-Versuche mit in Östrogen vorinkubierten RAW264.7-NOD2-/- Zellen zeigten eine eindeutige Synergie der TLR4- und NOD2-Rezeptoren in der IL-1beta-Ausschüttung. Östrogen scheint weiblichen Individuen einen protektiven Vorteil vor Infektionen bei NOD2-Defizienz zu verschaffen. / Toll-like receptors (TLR) and nod-like receptors (NLR) are pattern-recognition receptors that recognize lipopolysaccharide (LPS), lipopeptides and myramyldipeptide (MDP) derived from bacterial cell wall. We focus our question on the regulation of the pro-inflammatory cytokine interleukin (IL)-1beta during bacterial meningitis in primary murine astrocytes and microglia as well as cell lines and the synergism of TLR4 or TLR2 and NOD2 to amplify IL-1beta-expression. ProIL-1beta is expressed by TLR-stimulation and activation of NF-kB signal transduction. Through the activation of Caspase-1, possibly through NOD2 and the inflammasome, proIL-1beta is cleaved on post-translational level and obtains its activated status, leading to pathogen elimination during bacterial meningitis. Primary murine WT-astrocytes and a human cell line primed with LPS or lipopeptide and stimulated with MDP show significantly increased IL-1beta levels in the supernatant. NOD2-/- astrocytes do not show elevated IL-1beta levels. After screening of cytoplasmic proCaspase-1 and activated Caspase-1 by Western blot it became clear, that stimulation of NOD2 with MDP led to Caspase-1 activation and thus to IL-1beta maturation in primary murine WT-astrocytes. We demonstrate for the first time that the synergism between TLR4 and NOD2 leads to significantly elevated IL-1beta levels and that NOD2 is capable of activating caspase-1 in primary murine astrocytes. Another part of the work was to test the TLR/NLR-synergism on primary peritoneal macrophages from adult mice. Surprisingly, female NOD2-/- mice showed significantly elevated IL-1beta levels. SiRNA- and stimulation-experiments with RAW264.7-NOD2-/- cells pre-incubated in estrogen show a clear synergy in IL-1beta secretion through TLR4 and NOD2 receptors. Estrogen seems to protect females from infection when having a NOD2 deficiency.

Introdução: O implante auditivo de tronco encefálico (ABI) é indicado para pacientes com perda auditiva neurossensorial severa a profunda quando há impossibilidade de realização do implante coclear. Em pacientes com surdez por meningite e ossificação coclear total bilateral, o ABI é a opção para a reabilitação auditiva. Objetivos: O estudo tem por objetivo avaliar a contribuição do ABI para os limiares audiométricos e para a percepção de fala após no mínimo 12 meses de uso em pacientes com ossificação coclear total por surdez pós-meningite, bem como descrever as complicações do procedimento. Material e métodos: Dez pacientes com surdez pósmeningite foram submetidos ao ABI por via retrolabiríntica ampliada em um centro terciário de assistência e ensino. Todos os pacientes foram operados pela mesma equipe cirúrgica e a avaliação audiológica foi realizada pelo mesmo fonoaudiólogo. Foram realizados audiometria tonal e testes de percepção de fala no pré-operatório e no mínimo 12 meses após a ativação do implante. Foram descritas as complicações associadas ao procedimento. Resultados: Oito de dez pacientes implantados permaneceram usuários. Dois pacientes não apresentaram respostas auditivas e abandonaram o seguimento. Os oito pacientes apresentaram melhora estatisticamente significativa nos limiares audiométricos, bem como nos testes de discriminação de palavras e vogais comparando pré e pós-operatório com média de seguimento de 3,3 anos. Em dois pacientes, a discriminação de sentenças em formato fechado somente no modo auditivo foi de 30% e 40%. Todos os oito usuários referiram benefício com o uso do ABI. Não houve complicações relacionadas ao procedimento. Conclusão: O ABI via retrolabiríntica ampliada é uma opção terapêutica segura para pacientes com surdez pós-meningite e com presença de ossificação coclear total bilateral, contribuindo para melhora nos limiares audiométricos e nos testes de percepção de fala. Embora a melhora nos testes audiológicos seja inferior à do implante coclear, a maioria dos pacientes do estudo usa o ABI diariamente por um período superior a 8 horas e refere benefício em seu cotidiano / Introduction: The Auditory Brainstem Implant (ABI) is an option to auditory restoration in patients with severe to profound sensorineural hearing loss who cannot be fitted with a cochlear implant. This is the only option in patients with post meningitis hearing loss presenting with bilateral total cochlear ossification. Objectives: The main objective of the study is to evaluate the hearing contribution in audiometry and speech perception tests at least 12 months after ABI implantation in patients with post-meningitis profound hearing loss. The complications of the procedure were also described. Materials and Methods: Ten patients with post-meningitis hearing loss went an ABI through extended retrolabyrinthine approach in a tertiary center by the same surgeons. The same audiologist was responsible for audiological follow-up. Tonal audiometry and speech perception tests were made before and at least 12 months after the ABI activation. The procedure complications were described for all patients. Results: Eight of ten patients became ABI users. Two patients had no auditory response and abandoned the treatment. Eight users showed benefit in tonal audiometry, word and vowels perception tests after an average follow up of 3.3 years. Two patients were able to recognize 30 and 40% of closed sentences without lip reading. There were no complications due to the ABI procedure. Conclusion: The extended retrolabyrinthine approach for the ABI is a safe surgical option for patients with post-meningitis hearing loss and totally ossified cochleae. It contributes to hearing performance in audiometry and speech perception tests. Even though the ABI results are poorer than the cochlear implants, in this study the majority of patients use their ABI more than eight hours a day and report benefits in daily activities

The invention of the vaccine has been one of the greatest public health triumphs of the modern world. Each new vaccine has saved thousands - even millions - of lives worldwide, but this success has been fraught with controversy over the safety and even the effectiveness of vaccines. Vaccines have not always had a spotless safety record, but today’s vaccines are incredibly safe and continue to protect millions of people against diseases that have significantly declined or nearly disappeared from the developing world. It is this very success that has led many people to forget, or never discover, what those diseases are and how destructive they can be. This report tells the story of several families whose lives were deeply affected by vaccine-preventable diseases, accompanied with images that help tell their story. Following these stories is a broader discussion of the issues related to vaccines, the misunderstandings and misinformation that often circulate about them, a brief mention of their safety and efficacy, and a general discussion of many of the diseases they can prevent. / text