Thèse d'exercice : Médecine. Médecine générale : Paris 12 : 2004. / Titre provenant de l'écran-titre. Bibliogr.

Die „Hygiene Hypothese“ postuliert, dass der Kontakt mit Infektionserregern in der frühen Kindheit die Entwicklung von Th2-abhängigen allergischen Immunreaktionen verhindern kann, indem dadurch entweder eine vorrangig Th1-gerichtete Immunität etabliert wird oder alternativ die Bildung von regulatorischen T Zellen induziert wird. Basierend auf dieser Theorie zielte die vorliegende Arbeit darauf ab, Produkte von Mikroorganismen oder Würmern als mögliche Komponenten von Impfstoffen gegen Allergien zu testen. Im ersten Teil dieser Arbeit wurden lebende BCG, Hitze abgetötete BCG (hk-BCG), CpG und PPD, die alle als Th1 Adjuvantien bekannt sind, auf ihre Effektivität getestet, allergisches Asthma in der Maus zu unterdrücken. Alle Adjuvantien konnten die durch Allergie induzierte Lungeneosinophilie, die Schleimproduktion in der Lunge und mit Ausnahme von PPD, die Lungenüberempfindlichkeit (AHR) unterdrücken, wenn sie zusammen mit OVA/alum verabreicht wurden. Die Lungeneosinophilie konnte jedoch nicht in IL-12 oder IFN-gamma defizienten Mäusen durch die Applikation von hk-BCG, CpG oder PPD verhindert werden. Interessanterweise waren jedoch lebende BCG in der Lage, die allergische Th2 Immunreaktion zu unterdrücken. Ebenso war die Wirkung von lebendem BCG unabhängig vom IL-10, TLR-2, TLR-4 oder MyD88 vermittelten Signalweg. Wurden Mäuse, die mit den verschiedenen Adjuvantien zusammen mit OVA/alum geimpft wurden, einer zweiten Runde OVA/alum Sensibilisierung unterzogen, so konnten nur lebende und hk-BCG die Entwicklung der Entzündung in der Lunge effektiv unterdrücken. Diese Wirkung konnte durch den adoptiven Transfer von CD4+ T Zellen auf naive Mäuse übertragen werden. Zusammenfassend zeigen diese Daten, daß lebende BCG am effektivsten, gefolgt von hk-BCG, CpG und schließlich PPD allergische Th2 Immunreaktionen unterdrücken konnten. Als nächstes wurde untersucht, ob eine Impfung mit dendritischen Zellen (DC) die Entwicklung von Th2 Zellen durch die Induktion von allergenspezifischen Th1 Zellen verhindern kann. Die Applikation von OVA-gepulsten aus dem Knochenmark stammenden-dendritischen Zellen (BM-DC), die mit CpG in vitro stimuliert wurden, konnten die Lungeneosinophilie und Entzündung in den Atemwegen in OVA-immunisierten Mäusen nicht reduzieren. OVA-spezifische IgG1 und IgE Antikörpermengen im Serum waren ebenfalls nicht vermindert. Versuche mit OVA-gepulsten Langerhans-zellen (LC) führten zu ähnlichen Ergebnissen wie mit BM-DC. Jedoch waren in Mäusen, die mit CpG/OVA gepulsten BM-DC behandelt wurden, deutlich erhöhte Werte an OVA-spezifischen IgG2a Antikörper im Serum nachzuweisen, was auf die Induktion einer allergenspezifischen Th1 Immunreaktion in vivo schließen läßt. Insgesamt zeigen die Ergebnisse aber, dass weder die Impfung mit OVA-gepulsten und CpG-stimulierten BM-DC noch mit OVA-gepulsten LC eine Verringerung der allergischen Th2 Immunreaktion in einem Mausmodell mit schwerem atopischem Asthma bewirkt. Im dritten Teil der Arbeit wurde NES, ein exkretorisches/sekretorisches Produkt des Helminthen Nippostrongylus brasiliensis, als ein neues mögliches Adjuvant zur Unterdrückung allergischer Reaktionen untersucht. Die Applikation von NES zusammen mit OVA/alum inhibierte deutlich die Entwicklung der Lungeneosinophilie, Becherzellmetaplasie und Schleimproduktion in der Lunge sowie die Entwicklung der AHR. Das verwendete NES enthielt geringe Mengen an LPS, die diese Wirkung erklären könnte. Allerdings war die Unterdrückung der Th2 Immunreaktion durch NES unabhängig von TLR-4 und konnte immer noch nachgewiesen werden, wenn LPS-depletiertes NES verwendet wurde. Schließlich konnte NES die OVA-induzierte Th2 Immunreaktion unabhängig von IL-10 und IFN-gamma reduzieren. Außerdem konnte der Verdau von NES mit Proteinase K oder eine Hitzebehandlung (kochen) den Th2-unterdrückenden Effekt nicht aufheben. Interessanterweise inhibierte NES in vivo eine OVA-spezifische Th2 Immunreaktion in Anwesenheit einer starken NES-spezifischen Th2 Reaktion. Zusammenfassend führen diese Ergebnisse zu dem Schluß, daß der Helminth N. brasiliensis Substanzen produziert, die die Entwicklung von allergischen Th2 Immunreaktionen beeinflussen. Diese Produkte und ihre Wirkmechanismen genauer zu charakterisieren, könnte zu sehr effektiven Adjuvantien führen, welche allergische Reaktionen unterdrücken könnten. Die Ergebnisse dieser Arbeit könnten zukünftig dazu beitragen, effiziente Impfungen zu entwickeln, die Menschen vor der Entwicklung von allergischen Immunreaktionen schützen. / According to the hygiene hypothesis, the exposure to infectious agents in early childhood prevents the development of allergen-specific Th2 immune responses because it establishes Th1-based immunity or alternatively, induces the generation of T regulatory cells. Based on this theory, the present study pretended to identify promising microorganism-derived vaccine candidates against allergic asthma in the murine model. In the first part of this work, the efficacy of four different known Th1-inducing adjuvants, i.e. live BCG, heat-killed BCG, CpG and PPD, as components of vaccines aimed at inhibiting allergic asthma was compared. All the adjuvants were effective in inhibiting the development of allergen-induced airway eosinophilia, mucus production, and with the exception of PPD also airway hyperreactivity (AHR), when they were applied together with OVA/alum. Suppression of airway eosinophilia was not observed in IFN-gamma- or IL-12-deficient mice (hk-BCG, CpG-ODN and PPD). Interestingly, live BCG was still able to suppress allergen-induced Th2 responses in the absence of either IFN-gamma or IL-12. The effect of live BCG was also independent on IL-10-, TLR-2-, TLR-4- or MyD88-mediated signaling. When mice vaccinated with the different adjuvants together with OVA/alum were subjected to a second period of OVA/alum immunization, only live and hk-BCG were able to efficiently suppress the development of airway inflammation. This effect could be adoptively transferred by CD4+ T cells. Taken together our data suggest that live BCG>>hk-BCG>CpG>PPD are effective in suppressing allergen-induced Th2 responses. Secondly, the evaluation of a dendritic cell-based vaccination strategy leading to the induction of allergen-specific Th1 cells to protect against the development of allergen-specific Th2 responses was performed. The application of OVA-pulsed BM-DC maturated with CpG was unable to reduce airway eosinophilia and inflammation in OVA-immunized mice. OVA-specific IgG1 or IgE serum levels were also not reduced. The experiments using LC pulsed with OVA yielded similar results. However, the mice vaccinated with CpG/OVA pulsed BM-DC had greatly enhanced levels of OVA-specific IgG2a in the serum, suggesting the induction of allergen-specific Th1 responses in vivo. Thus, these data suggest that the vaccination of mice with OVA-pulsed BM-DC matured with CpG or OVA-pulsed LC did not result in a reduction of allergen-specific Th2 responses in a murine model of severe atopic asthma. Lastly, NES, an excretory/secretory product derived from the helminth Nippostrongylus brasiliensis was evaluated as a new potential adjuvant to prevent the development of allergic responses. The application of NES together with OVA/alum greatly inhibited the development of airway eosinophilia, airway goblet cell metaplasia and mucus production and the development of airway hyperreactivity after metacholine challenge. Furthermore, OVA-specific IgG1 and IgE levels in the serum were also strongly reduced. NES preparations contained small amounts of endotoxin, which may explain these results. However, the suppressive effects of NES on the development of allergen-specific Th2 responses was independent upon IFN-gamma or TLR-4 and still observed in mice treated with LPS-depleted NES. NES reduced OVA-induced Th2 responses also in a IL-10-independent manner. In addition, the digestion with proteinase K or the heat-treatment of NES did not abolish its ability to inhibit allergen-induced Th2 responses. Interestingly, NES suppress OVA-specific Th2 responses in vivo in the presence of a strong NES-specific Th2 environment. Taken together our results suggest that the helminth N. brasiliensis secretes substances which interfere with the development of allergic Th2 responses. In summary, distinct substances derived from microorganisms or helminths which may be used as potential adjuvants to prevent the development of allergic Th2 responses were identified. These findings contribute to the design of efficient vaccines protecting humans from developing allergic asthma.

Thesis advisor: Devin Pendas / Thesis advisor: James Cronin / Political structures, ideology, and science interact to shape public health policy in a way that is complex and still poorly understood. The German experience in the 20th century creates a unique historical opportunity for studying this interplay. This study examines the development and variation of tuberculosis control measures under the Kaiser Reich, during the Weimar Republic, in the era of Nazism, and in the post-1945 occupation zones and subsequent German states. This dissertation examines major milestones in scientific understanding, medical practice, public health policy, legislation, and regulation related to tuberculosis control under successive German states and governments will help to clarify their interaction. In the course of this turbulent German century, profound changes occurred in the scientific understanding of tuberculosis. Tuberculosis had reached epidemic proportions in Germany in the wake of the industrial revolution, spurring considerable research into its origins, treatment, and the conditions of its spread. Robert Koch's 1882 discovery of the tuberculosis bacillus launched a period of progress in diagnosis and treatment that coincided with increased political interest in public health more generally. Only with the discovery of streptomycin in 1945 did medical science begin to develop the first effective drug therapies and struggled with questions of how to integrate these into existing treatment and prevention paradigms. Here, a comparison between the East and West German experience proves particularly helpful in exploring the importance of ideology, politics, medical knowledge, as well as institutional and professional interests. Ultimately, through the case study of tuberculosis treatment and control, this dissertation examines how the interaction between various German states' ideologies, their medical traditions, and their scientific knowledge shaped Germany's public health policies and practices. / Thesis (PhD) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: History.

O presente estudo se propôs a determinar o efeito protetor da vacinação intradérmica com BCG (bacilo e Calmette-Guérin) em contatos de pacientes de hanseníase através do desenho de estudo caso-controle. Selecionou-se 65 casos e 904 controles, de zero a 29 anos de idade, provenientes de uma população base de contatos de pacientes de hanseníase residentes no Município e Área Metropolitana do Rio de Janeiro (área endêmica de hanseníase). De ambos os grupos obteve-se informações quanto a exposição ao BCC (presença ou ausência de cicatriz vacinal), idade, sexo, tipo de contato, parentesco e forma clínica do caso primário. Informações adicionais do caso são acessíveis tais como: forma clínica, bacterioscopia, Mitsuda e grau de incapacidade. Realizou-se análise não pareada dos dados onde a presença de cicatriz de BCG mostrou-se negativamente associada com hanseníase indicando uma eficácia protetora de 59% (95% I.C. = 29 k -77%). A análise estratificada não revelou que as variáveis idade, sexo, tipo de contato, parentesco e forma clínica do caso primário introduziram confusão na avaliação da eficácia vacinal. Discute-se a adequação do desenho de estudo tipo caso-controle para a avaliação de eficácia vacinal em doença crônica, as implicações dos resultados e sua importância para a atividade de vigilância de contatos no Programa de Controle da Hanseníase.

Práce se věnuje zmapování hlavní konkurence působící na leasingovém trhu ve vztahu ke společnosti ČSOB Leasing, a.s. Analyzuje aktuální stav na trhu, příležitosti a ohrožení, které trh představuje a také silné a slabé stránky jednotlivých konkurentů. V posledních částech se pak práce zaměřuje na formulaci doporučení, která mohou pomoci ČSOB Leasing, a.s. ještě posílit konkurenční postavení, a na které oblasti by se společnost mohla zaměřit při dalších analýzách.

Tuberculosis is a re-emerging global health problem. Bacille Calmette-Guerin (BCG), the available vaccine against the disease, is only effective short term and is associated with adverse reactions clinically. The development of new effective vaccines will require an understanding of virulence, immunogenic factors and the beneficial immune responses induced in the human host. My thesis investigates phoP and whiB3, two genes associated with virulence and immunogenicity in Mycobacterium tuberculosis. Study of PhoP in a natural phoP mutant, BCG-Prague, and in the clinically safe BCG-Japan, shows that over-expression of PhoP increases the immunogenicity of these vaccine strains. In addition, I found that WhiB3 impacts carbon metabolism in BCG-Birkhaug and BCG-Sweden, although the effect of this on virulence in vivo is still unclear. The characterization of genes involved in virulence and immunogenicity allows us to develop novel approaches for improving the efficacy of BCG, which has important implications for future TB vaccine development.

Tuberculosis is a re-emerging global health problem. Bacille Calmette-Guerin (BCG), the available vaccine against the disease, is only effective short term and is associated with adverse reactions clinically. The development of new effective vaccines will require an understanding of virulence, immunogenic factors and the beneficial immune responses induced in the human host. My thesis investigates phoP and whiB3, two genes associated with virulence and immunogenicity in Mycobacterium tuberculosis. Study of PhoP in a natural phoP mutant, BCG-Prague, and in the clinically safe BCG-Japan, shows that over-expression of PhoP increases the immunogenicity of these vaccine strains. In addition, I found that WhiB3 impacts carbon metabolism in BCG-Birkhaug and BCG-Sweden, although the effect of this on virulence in vivo is still unclear. The characterization of genes involved in virulence and immunogenicity allows us to develop novel approaches for improving the efficacy of BCG, which has important implications for future TB vaccine development.

The outcome of an infection is often determined by the qualitative nature of the immune response generated against the infectious agent. Various intracellular pathogens, including those that cause leprosy, tuberculosis, leishmaniasis, and most probably malaria and AIDS appear to require a predominant cell-mediated, Th1, response for effective containment, whereas the generation of a mixed Th1/Th2 or predominantly Th2 response is associated with progressive disease. Therefore, any attempt to develop universally efficacious vaccination against these pathogens must generate an immunological imprint that ensures a strong and stable cell-mediated response upon natural infection with the relevant pathogen. We report here critical tests of a strategy designed to achieve such an imprint using Bacille-Calmette-Guérin (BCG) vaccine. BCG vaccine is an attenuated form of M. bovis, the causative agent of tuberculosis in cattle, and is the most widely used vaccine in humans. However, considerable uncertainty still surrounds its efficacy against tuberculosis both in man and animals. As the protective dose is not known, BCG has been given at the maximum tolerable dose. However, recent studies in mice and other animals have shown that the dose of an antigen can be a critical factor in determining the type of immune response generated. I tested the general hypothesis that low dose vaccination would preferentially induce cell-mediated immune response and generate a Th1 imprint that can protect the host against intracellular pathogens in the particular case of mycobacteria. To this end, both adult and newborn mice were vaccinated with different doses of BCG or saline and cell-mediated and humoral immune responses were assessed at different times post-vaccination. Several weeks after vaccination, mice from each group were challenged with a dose of BCG that induces a mixed Th1/Th2 response in naïve mice, and the T-cell and antibody responses were assessed using ELISPOT and ELISA assays, respectively. The splenic bacterial burden was also determined using colony formation on agar plates. <p>Our results show that the class of immunity induced by BCG depends on the dose employed for vaccination, independent of the route of administration and the age and strain of mice used. In all cases, lower doses induce an exclusive cell-mediated, Th1, response with no antibody production, while higher doses induce either a mixed Th1/Th2 response or a predominantly Th2, humoral response, with higher titers of both IgG1 and IgG2a antibodies. Following intravenous high dose BCG challenge, all mice in the vaccinated groups developed a Th1 response associated with a more efficient clearance of BCG from the spleen. The greatest clearance of mycobacteria was generated following vaccination with lower doses, as low as 33 cfu of BCG. In addition, our findings demonstrate that newborn mice are not inherently biased towards generating Th2 responses, but they can generate Th1 responses and Th1 imprints if appropriate vaccination protocols (dose, route and time) are employed. Furthermore, subcutaneous exposure of young mice to environmental mycobacteria can induce a mixed Th1/Th2 response that can abrogate the potential to generate Th1 responses and Th1 imprints upon vaccination with low doses of BCG vaccine. Low dose neonatal BCG vaccination can circumvent the interference caused by impingement of environmental mycobacteria on the immune system. Therefore, our observations strongly support a neonatal low dose BCG vaccination strategy to provide universally efficacious protection against infections by pathogenic mycobacteria.

The outcome of an infection is often determined by the qualitative nature of the immune response generated against the infectious agent. Various intracellular pathogens, including those that cause leprosy, tuberculosis, leishmaniasis, and most probably malaria and AIDS appear to require a predominant cell-mediated, Th1, response for effective containment, whereas the generation of a mixed Th1/Th2 or predominantly Th2 response is associated with progressive disease. Therefore, any attempt to develop universally efficacious vaccination against these pathogens must generate an immunological imprint that ensures a strong and stable cell-mediated response upon natural infection with the relevant pathogen. We report here critical tests of a strategy designed to achieve such an imprint using Bacille-Calmette-Guérin (BCG) vaccine. BCG vaccine is an attenuated form of M. bovis, the causative agent of tuberculosis in cattle, and is the most widely used vaccine in humans. However, considerable uncertainty still surrounds its efficacy against tuberculosis both in man and animals. As the protective dose is not known, BCG has been given at the maximum tolerable dose. However, recent studies in mice and other animals have shown that the dose of an antigen can be a critical factor in determining the type of immune response generated. I tested the general hypothesis that low dose vaccination would preferentially induce cell-mediated immune response and generate a Th1 imprint that can protect the host against intracellular pathogens in the particular case of mycobacteria. To this end, both adult and newborn mice were vaccinated with different doses of BCG or saline and cell-mediated and humoral immune responses were assessed at different times post-vaccination. Several weeks after vaccination, mice from each group were challenged with a dose of BCG that induces a mixed Th1/Th2 response in naïve mice, and the T-cell and antibody responses were assessed using ELISPOT and ELISA assays, respectively. The splenic bacterial burden was also determined using colony formation on agar plates. <p>Our results show that the class of immunity induced by BCG depends on the dose employed for vaccination, independent of the route of administration and the age and strain of mice used. In all cases, lower doses induce an exclusive cell-mediated, Th1, response with no antibody production, while higher doses induce either a mixed Th1/Th2 response or a predominantly Th2, humoral response, with higher titers of both IgG1 and IgG2a antibodies. Following intravenous high dose BCG challenge, all mice in the vaccinated groups developed a Th1 response associated with a more efficient clearance of BCG from the spleen. The greatest clearance of mycobacteria was generated following vaccination with lower doses, as low as 33 cfu of BCG. In addition, our findings demonstrate that newborn mice are not inherently biased towards generating Th2 responses, but they can generate Th1 responses and Th1 imprints if appropriate vaccination protocols (dose, route and time) are employed. Furthermore, subcutaneous exposure of young mice to environmental mycobacteria can induce a mixed Th1/Th2 response that can abrogate the potential to generate Th1 responses and Th1 imprints upon vaccination with low doses of BCG vaccine. Low dose neonatal BCG vaccination can circumvent the interference caused by impingement of environmental mycobacteria on the immune system. Therefore, our observations strongly support a neonatal low dose BCG vaccination strategy to provide universally efficacious protection against infections by pathogenic mycobacteria.

National Health Insurance (NHI) is more than 13 years in Taiwan. The NHI paid medical fees to service providers on the basis of "fee-for-service" in the beginning. However, the cases numbers were increased by health providers for erned more money. Besides, it was very difficult to review the cases. The health capital expenditure was increased gradually. The Bureau of National Health Insurance took a serial measures to finance control, such as ¡§case-payment¡¨, ¡§self-management¡¨, ¡§hospital excellence program¡¨ and ¡§global budget reimubursement system¡¨. But the medical needs elevate due to the life quality and life expectancy increased, unbalance of payments is very serious¡COur government began to investigate the excellent ¡§diagnosis related group payment system¡¨ which carried out in America and other OECD countries for many years. The prospective payment system made medical costs more easily control. Though Taiwan diagnosis related groups was finished and was revised to the third edition on the basis of experts consensus during many times of discussion, the exacted time of execution is delayed again and again. Mainly in Taiwan medical league doubted and blocked the new measure. Moreover, people worried about would become medical garbage because health institute refused critical patient owing to DRG fixed payment or few percentage additional charges, especially in medical centers. It might decrease the examination items and compromised the patient rights and quality of medical care. Eeverytimes when NHI implemented new measure to control medical capital expenditure, it resulted in some degree damage to medical institute in fact. This study analysed the regional hospital income and the difference of implementation DRG by major diagnosis categories and sections in 2006 and 2007 with BCG model. The hospital begame to promote DRG payment system in 2007, compared to 2006, may simulate the difference after implementation of DRG. We also compared the medical performance and medical care quality of 2007 to 2006 to simulate the difference after implementation of DRG. The thesis reviewed the results of execution DRG in others countries and summarized some experts and scholars advisement abut the impaction of DRG carried out in Taiwan. At last, we interviewed to the department directors about the opinions and suggestions of DRG in-depth and addressed the responsive strategies and balanced scorcard implementation¡C DRG payment system was proved as an excellent measure by others countries. It could control the medical cost effectively and did not compromise medical care quality. There are several measures, including ¡§global budget reimubursement system¡¨, ¡§case- payment¡¨ and ¡§fee-for-outcome¡¨in Taiwan. Is the result of DRG implementation in Taiwan diffierent to other DRG countaries¡HOur conclusions are implementation DRG may not damage to hospital finance and medical care quality may decrease a little in the first time. For checking on medical care quality critically, it is necessary for hospitals and Bureau of NHI to set up peer review organization