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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.
81

Avaliação das doenças chiadoras recorrentes da infância como fator de risco para pneumonia / Evaluation of recurrent wheezing diseases of childhood as a risk factor for pneumonia

Pereira, Julio Cesar Rodrigues 05 October 1995 (has links)
Comentando-se algumas evidências da literatura e da análise de dados secundários de morbidade e mortalidade, estabelece-se a hipótese de que as doenças chiadoras recorrentes da infância possam constituir-se em fator de risco para o desenvolvimento de infecções pulmonares. Um estudo caso-controle é desenvolvido para testar esta hipótese reunindo 51 casos de pneumonia pareados por sexo e idade a 51 controles sadios e 51 controles doentes não respiratórios. A amostra é colhida entre pacientes do Hospital Universitário da USP sendo condição de entrada para os casos um diagnóstico de pneumonia adquirida na comunidade e livre de tratamento anterior. Os controles são selecionados dentro da mesma clientela entre pacientes com outro diagnóstico e crianças sadias usuárias dos mesmos serviços, identificadas entre acompanhantes de pacientes. Casos e controles são submetidos a idêntica investigação quanto a presença de doença (pneumonia) e de exposição ao fator de risco investigado (doença chiadora recorrente) através de anamnese e exame físico padronizados, realizados independentemente por dois observadores distintos. Ambos os observadores são pediatras designados pelo Departamento de Pediatria do Hospital para esta tarefa e recebem orientação e supervisão para uma observação padronizada. Os dados assim recolhidos são processados em análises estatísticas uni e multivariadas para explorar diferenças entre casos e controles. A amostra estudada resulta constituída por crianças de idade média de 2 anos (com variação entre um mês e sete anos), entre as quais 47 por cento são meninos. O diagnóstico de pneumonia é validado através da aplicação de análise discriminante multivariada das informações relativas a sinais clínicos, encontrando-se uma compatibilidade entre a conclusão clínica e estes sinais da ordem de pelo menos 75 por cento . O diagnóstico de exposição a doença chiadora é validado pela presença de história compatível segundo premissas pré-estabelecidas nos métodos do estudo (diagnóstico de asma e pelo menos um episódio de dispnéia nos últimos 12 meses ou história de chiado recorrente que melhora com medicação e pelo menos dois episódios nos últimos 12 meses) em 40 dos 41 expostos identificados. O questionário de identificação da exposição tem a repitibilidade medida através de sua reaplicação pelo mesmo observador a uma amostra de 20 por cento do total de crianças examinadas. Encontra-se um nível geral de concordância entre a primeira e segunda aplicação do questionário de 76,7 por cento e um índice Kappa de 0,65. A associação entre pneumonia e doença chiadora recorrente é analisada através de regressão logística com controle para todas as variáveis que em análise univariada mostram frequência estatisticamente significante entre casos e controles. Encontra-se que o risco de pneumonia entre crianças expostas a doença chiadora é 7 vezes maior do que entre crianças não expostas, controladas a renda familiar e a situação de aglomeração no quarto de dormir, também identificadas como fatores de risco para pneumonia (\"odds ratio\" de 5,6 e 2,4 para rendas baixa e média comparadas com renda alta e \"odds ratio\" de 1,5 para cada pessoa a mais no quarto de dormir). Calcula-se que para a comunidade hospitalar estudada a doença chiadora recorrente represente um risco atribuível para pneumonia entre 33 por cento e 51 por cento , conforme a aplicação de diferentes técnicas de cálculo. Conclui-se que as doenças chiadoras recorrentes da infância constituem-se em importante fator de risco para pneumonia e que seu controle, através da inclusão de assistência sistemática a pacientes com este diagnóstico nos programas de Saúde Pública para o controle de doenças respiratórias da infância, pode ter importante impacto sobre a incidência de pneumonias. / Taking into account some evidences from the literature and from analysis of available data, a hyphothesis that childhood wheezing diseases are related to pneunomia is established. A case-control study is designed to test this hypothesis taking 51 cases of pneumonia matched by sex and age to 51 healthy and 51 non-respiratory controls. The sample is drawn from patients of the \"Hospital Universitário da USP\". Entry condition for cases is to bear a community acquired pneumonia free of previous treatment and for controls is to be custommer of the same health services. Cases and controls are equally investigated with regards to the presence of pneumonia and history of wheezing diseases, investigation being conducted by two independent observers. Both are paediatricians selected by the Hospital Paediatric Department and are dully trained and supervised as to assure a standardized observation. Data are processed in oneway and multivariate statistical analyses to explore diferences between cases and controls. The sample studied comprises children aged 2 years in average (range between one month and seven years) and male subjects account for 47 per cent of the total. The diagnosis of pneumonia is validated through multivariate discriminant analysis which shows that clinical opinion is compatible to clinical signs in at least 75 per cent of the cases. The clinical conclusion of presence of wheezing disease is found compatible to previously defined criteria in 40 out of 41 patients. Repeatability of such information is assessed by re-aplication of the questionnaire for wheezing disease investigation to a sample of 20 per cent of the total number of children, which is carried out by the same observer of the first interview. An overall agreement of 76.7 per cent and a Kappa of 0.65 is found. Association between pneumonia and wheezing disease is analysed through logistic regression controlling the effects of all variables which have shown statistically significant differences between cases and controls. It is found that children who bear a wheezing disease have a risk to pneumonia which is 7 times greater than those who do not, allowing for socioeconomic status and bedroom crowding, both also risk fators: odds ratio of 5.6 and 2.4 for low and medium family income as opposed to high income and odds ratio of 1.5 for each increase of one person in bedroom.Derived from different techniques, an attributable risk for wheezing disease ranging from 33 per cent to 51 per cent is calculated. It is concluded that wheezing diseases of childhood are an important risk factor to pneumonia and that its control, by means of regular medical assistance of patients being included among the items of current public health programmes, should result in an important effect over the frequency of pneumonia.
82

Tolerância cruzada no modelo de inflamação pulmonar alérgica experimental. / Cross-tolerance in a model of experimental allergic lung inflammation.

Balbino, Bianca 02 December 2014 (has links)
A tolerância pode ser considerada um dos pilares da imunologia. Sabe-se que a tolerância a um antígeno pode gerar tolerância a outro antígeno não relacionado, fenômeno conhecido como tolerância cruzada. Neste trabalho caracterizamos a tolerância cruzada utilizando a OVA como tolerógeno e extrato de Blomia tropicalis (Bt) ou Hemocianina de Keyhole limpet (KLH) como alérgenos. Verificamos que é possível reproduzir o fenômeno da tolerância cruzada neste modelo de inflamação alérgica induzida tanto pelo KLH quanto pela Bt, com diminuição do infiltrado inflamatório no pulmão, eosinófilos, IgE total e produção de muco. Ainda, a estratégia de utilizar a tolerância cruzada terapeuticamente, i.é., após a sensibilização com KLH, a indução de tolerância cruzada não foi capaz de prevenir a resposta alérgica. Em conjunto, nossos dados mostram que a tolerância à OVA modifica as respostas alérgicas tanto à Bt quanto ao KLH no modelo de inflamação pulmonar experimental de forma profilática, mas que a tolerância cruzada não é eficiente em animais já sensibilizados. / Tolerance is among the Immunology pillars. Experimental data indicate that tolerance towards an antigen can promote tolerance to an unrelated antigen, a phenomenon known as cross-tolerance. Here we sought to characterize cross tolerance using OVA as a tolerogen and Blomia tropicalis (Bt) extract or Keyhole limpet Hemocianina (KLH) as allergens. We found that cross tolerance can be reproduced in the model of allergic lung disease induced by KLH or Bt, with less inflammatory infiltrate in the lung, eosinophils, total IgE and mucus production. Using cross tolerance therapeutically, i.e., after KLH sensitization, was not effective, since the allergic lung response was not modulated. Altogether, our data shows that OVA tolerance modulate allergic lung disease induced either by Bt or KLH when used as prophylactic model, however cross tolerance is ineffective in sensitized animals.
83

Estudo funcional do acometimento das pequenas vias aéreas nas pneumopatias intersticiais fibrosantes / Physiological study of small airwayfunction in fibrosing interstitial lung disease

Salge, João Marcos 23 February 2007 (has links)
Apesar de bem estabelecido em termos morfológicos, a repercussão funcional do envolvimento das pequenas vias aéreas nas pneumopatias intersticiais fibrosantes (PIF) permanece controversa. O presente estudo avaliou de maneira invasiva e não-invasiva (espirometria, volume de fechamento, variação da complacência dinâmica com a freqüência respiratória) a função das pequenas vias aéreas em portadores de PIF, comparando com grupo controle e correlacionando com índices morfométricos de biópsias. Os testes funcionais não diferenciaram portadores da doença dos controles quanto ao acomentimento das pequenas via aéreas e não se correlacionaram com os dados morfométricos / Although well known involvement of small airway in fibrosing interstitial lung disease based on morfologic issues, its functional consequences remains controversial. We present an invasive and non-invasive physiologic study for small airway function (pulmonary function tests, closing volume and frequency dependence of dynamic compliance) in patients with lung fibrosis. The physiological data were compared with normal controls and correlated with morfometric measurements from biopsies. Specific small airway function data could not show obstructive pattern when compared with normals, and did not correlate with morofmetric data
84

Der Nachweis von Plasmazytoiden Monozyten in der Bronchoalveolären Lavage - Methodik und klinische Bedeutung

Mahlig, Kirsten 12 July 1999 (has links)
Die Rationale für immuntherapeutische Ansätze zur Behandlung maligner Neoplasien geht davon aus, daß Tumore über spezifische Tumorantigene verfügen. Dendritische Zellen als die wichtigsten antigenpräsentierenden Zellen sind in der Lage, Tumorantigene naiven T-Zellen zu präsentieren und spezifische zytotoxische T-Zellen zu stimulieren. In der vorliegenden Arbeit wurden dendritische Zellen durch Stimulation mit Interleukin-4 (IL-4) und Granulozyten/ Makrophagen Koloniestimulierender Faktor (GM-CSF) aus peripheren mononukleären Blutzellen gesunder Spender und an Tumoren des gastroenteropankreatischen Systems erkrankter Patienten generiert. Mit den dendritischen Zellen cokultivierte immunologische Effektorzellen (Zytokin- induzierte Killerzellen, CIK-Zellen) wurden im Zytotoxizitätstest gegen kolorektale und pankreatische Karzinomzellen eingesetzt. CIK-Zellen sind zytototoxische Zellen, die durch Stimulation mit Zytokinen aus peripheren Blutlymphozyten erzeugt werden. Durch die Cokultivierung der Effektorzellen mit dendritischen Zellen konnte eine signifikante Steigerung der unspezifischen zytotoxischen Wirkung der CIK-Zellen bewirkt werden. Zur Steigerung der spezifischen Zytotoxizität wurden dendritische Zellen mit dem Gesamtprotein der tumor- assoziierten Antigene cancer associated antigen (CA 19-9) und carcinoembryonic antigen (CEA) gepulst. Effektorzellen zeigten nach der Cokultur mit gepulsten dendritischen Zellen zytotoxische Wirkung gegen Targetzellen, die das zum Pulsen verwendete Tumorantigen auf der Zelloberfläche exprimieren. Die Antigenspezifität der zytotoxischen Wirkung konnte durch eine signifikant verminderte Zellyse nach Blockade des Tumorantigens auf den Targetzellen belegt werden. Erstmals beschrieben ist hier das Pulsen dendritischer Zellen mit sowohl autologen als auch allogenen Seren von Patienten mit erhöhten Tumormarkerspiegeln. Eine Kultivierung dendritischer Zellen in tumormarkerhaltigem Serum bewirkte dosisabhängig eine verstärkte zytotoxische Wirkung cokultivierter Effektorzellen gegen Tumorzellen. Die verstärkte Zellyse zeigte sich unabhängig vom allogenem oder autologem Charakter des Serums. Der immunstimulierende Effekt des Patientenserums konnte durch eine vorhergehende Hitzeinaktivierung des Serums neutralisiert werden. Die höchsten Zellysen wurden durch eine Kultivierung dendritischer Zellen in tumormarkerhaltigem Serum und zusätzlichem Pulsen mit exogenem Tumorantigen erreicht. Untersuchungen an komplett autologen Systemen reproduzierten die an Zellkulturen erhobenen Befunde. Hierfür wurden erfolgreich Primärkulturen kolorektaler Tumore etabliert.Aus dem Blut von Tumorpatienten wurden dendritische Zellen generiert, die mit autologem Serum kultiviert wurden. Die cokultivierten autologen Effektorzellen erwiesen sich im Zytotoxizitätstest gegen autologe Tumorzellen als zytotoxisch. Die Cokultivierung der Effektorzellen mit den dendritischen Zellen bewirkte bei beiden Zellpopulationen Veränderungen. Dendritische Zellen zeigten nach der Cokultur eine verstärkte Expression antigenpräsentierender und costimulatorischer Moleküle. Bei den CIK-Zellen kam es zu einem Anstieg der Proliferationsrate. Bei Untersuchungen zur Antigenspezifität von T-Zellrezeptoren konnte vermehrt antigenspezifischer T-Zellrezeptor nachgewiesen werden. Des weiteren stieg das Verhältnis zwischen zytotoxischen T-Zellen und T-Helferzellen zugunsten der zytotoxischen T-Zellen. In ELISpot-Untersuchungen wurde eine Zunahme Interferon-gamma sezernierender CIK-Zellen nachgewiesen. Dendritische Zellen ließen sich erfolgreich mit inaktiviertem Adenovirus, an das kovalent Poly-L-Lysin gekoppelt ist, transfizieren. Die für den adenoviralen Gentransfer benötigten Oberflächenstrukturen konnten auf dendritischen Zellen nachgewiesen werden. Zur Verbesserung der Zytotoxizität wurden dendritische Zellen erfolgreich mit dem Gen für den Transaktivator CIITA transfiziert. CIITA- transfizierte dendritische Zellen exprimierten vermehrt MHC Klasse II-Moleküle. Die transduzierten dendritischen Zellen induzierten bei cokultivierten Effektorzellen eine erhöhte unspezifische Zytotoxizität. Mit Tumorantigen gepulste dendritische Zellen können bei der Entwicklung immuntherapeutischer Protokolle bei malignen Neoplasien von Bedeutung sein. / The immunotherapeutic approach against malignant neoplasias appreciates that tumours encode tumour rejection antigens, that enable them to induce protective immunity. Dendritic cells are major antigen-presenting cells and are able to present tumour antigens to naive T-cells and stimulate cytotoxic T-cells in a specific manner. In the present graduation-manuscript dendritic cells were generated in the presence of Interleukin-4 and granulocyte/macrophage colony-stimulating factor (GM-CSF) from peripheral mononuclear blood cells of healthy donors and tumour-patients. Immunological effector cells termed cytokine-induced killer cells (CIK cells) were co-cultured with dendritic cells and tested for their cytotoxic capacity against colorectal and pancreatic cancer cell-lines in a LDH-release assay. CIK cells are cytotoxic lymphocytes generated by incubation of peripheral blood lymphocytes with different cytokines. Co-culture of effector cells with dendritic cells led to a significant increase of the cytotoxic effect of CIK cells. For a further increase of specific cytotoxicity dendritic cells were pulsed with total protein of the tumour-associated antigens cancer associated antigen CA 19-9 and carcinoembryonic antigen (CEA). Co-cultured effector cells showed an increase in cytotoxicity against tumour-antigen expressing target cells, after co-culture with pulsed dendritic cells. The specificity of the cytotoxic effect could be shown by blocking the tumour-antigens with a monoclonal antibody. Autologous and allogenec untreated serums from patients with elevated tumour-marker levels were also used for pulsing of dendritic cells. Similar to the results when using total protein for pulsing, a cultivation in serum of patients with elevated tumour marker levels caused an intensified cytotoxic effect of effector cells against tumour cells in a dose-dependent manner. The intensified cytotoxicity was seen independent of the allogenec or autologous character of the serum. The immuno-stimulating effect of the patient serum could be neutralized by preceding heat inactivating. The highest cytotoxicity was achieved by a cultivation of dendritic cells in serum from patients with elevated tumour marker levels and additional pulsing with exogenous tumour antigen. Experiments with completely autologous systems reproduced the results made with cell-lines. Primary cultures of colorectal tumours were established. Dendritic cells were generated from the blood of tumour patients and were cultivated in autologous serum. Co-cultured autologous effector cells showed cytotoxicity when used against autologous tumour cells. Co-culturing of effector cells with dendritic cells caused modifications at both cell populations. Dendritic cells showed an increase expression of antigen-presenting and co-stimulatory molecules. CIK cells showed a higher proliferation-rate when co-cultured. They express more antigen-specific T-cell receptor, and the cytotoxic T-cells to T-helper cells ratio increased. ELISpot-assays showed an increase of interferon gamma producing cells. Dendritic cells were successfully transduced by using an inactivated adenovirus, which covalently binds poly-L-lysine. Dendritic cells express the molecules that enables adenoviral gene delivery on their surface. For the improvement of cytotoxicity dendritic cells were transduced with the gene encoding for the transactivator CIITA. CIITA transduced dendritic cells increases expression of MHC class II molecules. Cytotoxicity experiments with transduced dendritic cells resulted in an increased induction of non-specific cytolysis from co-cultured effector cells. DC pulsed with tumour-antigens may have a major impact on immunotherapeutic protocols for cancer patients.
85

Role of chemerin and its receptor ChemR23 in the physiopathology of inflammatory lung diseases / Caractérisation du rôle de la chémérine et de son récepteur ChemR23 dans la physiopathologie des maladies pulmonaires inflammatoires

Bondue, Benjamin 28 October 2010 (has links)
Chemoattractant agents play a crucial role in the initiation of immune responses, by regulating the traffic and function of leucocyte populations. Their receptors are therefore considered as potential targets for the development of new therapies in the fields of cancer and inflammatory diseases. ChemR23, a previously orphan receptor discovered in the laboratory, is structurally related to receptors for chemoattractant agents. It is expressed on immature myeloid and plasmacytoid dendritic cells (mDCs and pDCs respectively), as well as on adipocytes, macrophages, NK and endothelial cells. Chemerin, the endogenous ligand of ChemR23, is abundant in various human samples originating from inflammatory diseases, including pleural effusions. Chemerin is secreted as an inactive precursor, prochemerin, and is activated by the removal of six or seven amino-acids from its carboxy-terminus by serine proteases, such as as cathepsin G and elastase. Chemerin acts as a chemoattractant agent of low nanomolar potency for macrophages, immature mDCs and pDCs. It is however more active on pDCs, in line with the higher expression of ChemR23 on these cells. pDCs possess important immunoregulatory properties in lung diseases, and their ability to secrete large amounts of type I interferon (IFN) upon viral infection makes them crucial players in anti-viral immunity.<p>According to these elements, and to the role of neutrophils in the physiopathology of many inflammatory lung diseases and in the generation of active chemerin, we began in 2007 to study the role of chemerin and its receptor ChemR23 in inflammatory lung diseases. We first characterized the mouse chemerin/ChemR23 system, and described that this system was very similar to the human one, in terms of distribution, pharmacology and functional properties. We then used wild type mice (WT) and mice invalidated for the receptor (ChemR23-/-) in various models of inflammatory lung diseases, including asthma, lung fibrosis, viral pneumonia, and acute lung injury. <p>Whereas the asthma and lung fibrosis models did not allow to demonstrate a significant role of the chemerin/ChemR23 system (possibly as a result of the lack of production of active chemerin in these models), infection by either the Pneumonia Virus of Mice (PVM), the mouse counterpart of human RSV, or by a murinized H1N1 influenza strain resulted in a significantly higher mortality rate in ChemR23-/- mice as compared to their WT counterparts. Using the PVM-induced pneumonia model, we observed that the excessive mortality of knock-out mice is caused by an inadequate and excessive innate immune response characterized by a massive recruitment of neutrophils to the lungs, associated with a delayed viral clearance and lower type I IFN synthesis. This latter observation suggested an impairment of pDC recruitment, according to the important contribution of pDCs to the production of type I IFNs in viral diseases, and the role of chemerin in the recruitment of these cells. We indeed confirmed a lower recruitment of pDCs in the lung of infected ChemR23-/- mice, as compared to WT mice. However, experiments of adoptive transfert and depletion of pDCs failed to proof a link between impaired pDC recruitment and the excessive morbidity and mortality observed in ChemR23-invalidated mice. <p>In parallel, we studied the role of the chemerin/ChemR23 system in the control of innate immune responses, by using a model of acute lung injury caused by the intra-tracheal instillation of bacterial lipopolysaccharide (LPS). In this model, administration of recombinant chemerin together with LPS in WT mice resulted in a significant (about 50%) reduction of neutrophil recruitment to both lung parenchyma and airways. Assessment of pro-inflammatory cytokines and chemokines in broncho-alveolar lavage fluids confirmed this anti-inflammatory effect of chemerin, which was ChemR23-dependent, as the inflammatory response of ChemR23-/- mice was unaffected by chemerin. In our hands, chemerin does not modulate macrophage functions, in contrast to data recently published by other groups, attributing anti-inflammatory effects of chemerin or chemerin-derived peptide to the modulation of macrophage activation and phagocytosis. Other hypotheses that could take our observations into account are presently investigated, including an immunomodulatory role of chemerin on lung epithelial or endothelial cells, and/or the ChemR23-dependent recruitment of subtypes of macrophages or other myeloid cells endowed with immunosuppressive properties. <p>In conclusion, our studies characterized the mouse chemerin/ChemR23 system and highlighted the role of this system in the physiopathology of some inflammatory lung diseases. Our results suggest that the chemerin/ChemR23 system might be considered as a potential therapeutic target for the development of future anti-infectious and anti-inflammatory therapies, particularly for viral pneumonia, which represent a major public health problem, as well as for acute respiratory distress syndrome (ARDS) following severe acute lung injuries.<p> <p><p>Les agents chimioattractants jouent un rôle fondamental dans l’initiation des réponses immunes en régulant le trafic et la fonction des populations leucocytaires. Leurs récepteurs constituent dès lors des cibles d’intérêt pour le développement de traitements contre les maladies inflammatoires et le cancer. Le laboratoire d’accueil a identifié le récepteur ChemR23, exprimé à la surface des cellules dendritiques myéloïdes (mDCs) et plasmacytoïdes (pDCs) immatures, des macrophages, des cellules NK, des adipocytes, et des cellules endothéliales. Le ligand endogène du récepteur ChemR23, la chémérine, est présent en abondance dans divers échantillons pathologiques d’origine inflammatoire. La chémérine est produite sous la forme d'un précurseur inactif, la prochémérine, qui nécessite pour devenir active le clivage protéolytique de six ou sept acides aminés à son extrémité carboxy-terminale. La chémérine induit le chimiotactisme des macrophages et des DCs immatures, et en particulier des pDCs immatures en accord avec l’expression plus importante de ChemR23 par les pDCs. Les pDCs jouent un rôle immunorégulateur important en pathologie pulmonaire, en particulier dans la physiopathologie des pneumonies virales, par leur capacité à produire d’importantes quantités d’interféron (IFN) de type I.<p>Compte tenu de ces éléments et du rôle des polynucléaires neutrophiles dans de nombreuses pathologies pulmonaires, ainsi que dans la génération de chémérine active à partir de son précurseur, nous avons débuté en octobre 2007, l’étude du rôle de la chémérine et de son récepteur ChemR23 dans le contrôle des pathologies pulmonaires inflammatoires. Nous avons tout d’abord caractérisé le système chémérine/ChemR23 chez la souris et avons montré que ce système présentait des caractéristiques similaires à celles décrites chez l’homme, en termes de distribution, de pharmacologie et de propriétés fonctionnelles. <p>Ensuite, nous avons comparé des souris sauvages et invalidées pour le récepteur ChemR23 (ChemR23-/-) dans divers modèles de pathologies pulmonaires. Les modèles d’asthme et de fibrose pulmonaire induite par instillation de bléomycine ou de silice n’ont pas permis de mettre en évidence un rôle important du couple chémérine/ChemR23, peut-être en raison de l’absence de génération de forme active de chémérine dans ces modèles. En revanche, l’administration de deux agents viraux différents, le PVM (Pneumonia Virus of Mice), l’équivalent murin du RSV humain, et un virus de l’influenza H1N1 murinisé, a résulté en un taux de mortalité 40% plus élevé pour les souris ChemR23-/- par rapport à leurs homologues sauvages. En utilisant le modèle de pneumonie induite par le PVM, nous avons montré que cette différence de mortalité est causée par une réponse immune inappropriée et excessive, associée à une réduction de l’élimination du virus, ainsi qu’à un déficit de synthèse d’IFN de type I. Les pDCs, dans un contexte d’infection virale, sont capables de synthétiser d’importantes quantités d’IFN de type I, et nous avons mis en évidence un déficit relatif de recrutement en pDCs chez les souris ChemR23-/- infectées. Néanmoins, les expériences de transfert adoptif et de déplétion de pDCs n’ont pas permis de lier ce défaut de recrutement à l’excès de morbidité et de mortalité observé chez les souris ChemR23-/- infectées. <p>En parallèle, le rôle de ce couple ligand-récepteur dans le contrôle des réponses immunitaires innées a été étudié dans un modèle de pneumopathie aiguë induite par instillation intra-trachéale de lipopolysaccharide (LPS). Dans ce modèle, l’administration simultanée de chémérine recombinante avec le LPS entraîne chez les souris sauvages une diminution significative (environ 50%) du nombre de polynucléaires neutrophiles recrutés dans les voies aériennes et dans le parenchyme pulmonaire, ainsi qu’une importante diminution de synthèse de cytokines pro-inflammatoires. Cet effet anti-inflammatoire de la chémérine est dépendant de ChemR23, et ne semble pas être secondaire à un effet de la chémérine sur l’activation des macrophages, contrairement à certaines données publiées récemment par d’autres groupes. D’autres hypothèses permettraient cependant de prendre en compte ces observations, notamment un effet de la chémérine sur les cellules épithéliales et/ou endothéliales pulmonaires, ainsi que sur le recrutement de sous-populations de macrophages ou d’autres cellules myéloïdes possédant des propriétés immunosuppressives. Des expériences complémentaires ont été initiées afin de tester ces hypothèses. <p>En conclusion, après avoir caractérisé le système chémérine/ChemR23 chez la souris, nos études ont permis de mettre en évidence le rôle de ce couple ligand/récepteur dans la physiopathologie de certaines pneumopathies inflammatoires, ouvrant ainsi de nouvelles perspectives thérapeutiques, en particulier pour le traitement des pneumopathies virales, qui constituent un problème de santé publique majeur, ainsi que des syndromes de détresse respiratoire aiguë (ARDS). / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished
86

Estudo funcional do acometimento das pequenas vias aéreas nas pneumopatias intersticiais fibrosantes / Physiological study of small airwayfunction in fibrosing interstitial lung disease

João Marcos Salge 23 February 2007 (has links)
Apesar de bem estabelecido em termos morfológicos, a repercussão funcional do envolvimento das pequenas vias aéreas nas pneumopatias intersticiais fibrosantes (PIF) permanece controversa. O presente estudo avaliou de maneira invasiva e não-invasiva (espirometria, volume de fechamento, variação da complacência dinâmica com a freqüência respiratória) a função das pequenas vias aéreas em portadores de PIF, comparando com grupo controle e correlacionando com índices morfométricos de biópsias. Os testes funcionais não diferenciaram portadores da doença dos controles quanto ao acomentimento das pequenas via aéreas e não se correlacionaram com os dados morfométricos / Although well known involvement of small airway in fibrosing interstitial lung disease based on morfologic issues, its functional consequences remains controversial. We present an invasive and non-invasive physiologic study for small airway function (pulmonary function tests, closing volume and frequency dependence of dynamic compliance) in patients with lung fibrosis. The physiological data were compared with normal controls and correlated with morfometric measurements from biopsies. Specific small airway function data could not show obstructive pattern when compared with normals, and did not correlate with morofmetric data
87

Redes neurais auto-organizáveis na caracterização de lesões intersticiais de pulmão em radiografia de tórax / Self-organizing neural networks in the characterization of interstitial lung diseases in chest radiographs.

Ambrosio, Paulo Eduardo 01 June 2007 (has links)
O desenvolvimento tecnológico proporciona uma melhoria na qualidade de vida devido à facilidade, rapidez e flexibilidade no acesso à informação. Na área biomédica, a tecnologia é reconhecidamente uma importante aliada, permitindo o rápido desenvolvimento de métodos e técnicas que auxiliam o profissional na atenção à saúde. Recentes avanços na análise computadorizada de imagens médicas contribuem para o diagnóstico precoce de uma série de doenças. Nesse trabalho é apresentada uma metodologia para o desenvolvimento de um sistema computacional para caracterização de padrões em imagens pulmonares, baseado em técnicas de redes neurais artificiais. No estudo, buscou-se verificar a utilização de redes neurais auto-organizáveis como ferramenta de extração de atributos e redução de dimensionalidade de imagens radiográficas de tórax, objetivando a caracterização de lesões intersticiais de pulmão. Para a redução de dimensionalidade e extração de atributos, implementou-se um algoritmo baseado nos mapas auto-organizáveis (SOM), com algumas variações, obtendo-se uma redução dos cerca de 3 milhões de pixels que compõe uma imagem, para 240 elementos. Para a classificação dos padrões, utilizou-se uma rede Perceptron multi-camadas (MLP), validada com a metodologia leave-one-out. Com uma base contendo 79 exemplos de padrão linear, 37 exemplos de padrão nodular, 30 exemplos de padrão misto, e 72 exemplos de padrão normal, o classificador obteve a média de 89,5% de acerto, sendo 100% de classificação correta para o padrão linear, 67,5% para o padrão nodular, 63,3% para o padrão misto, e 100% para o padrão normal. Os resultados obtidos comprovam a validade da metodologia. / The technological development provides an improvement in the quality of life due to easiness, speed and flexibility in the access to the information. In the biomedical area, the technology is admitted as an important allied, allowing the fast development of methods and techniques that assist the professional in the health care. Recent advances in the computerized analysis of medical images contribute for the precocious diagnosis of a series of diseases. In this work a methodology for the development of a computational system for characterization of patterns in pulmonary images, based in techniques of artificial neural networks is presented. In the study, has searched for the verification the use of self-organizing neural networks as a feature extraction and dimensionality reduction tool of chest radiographs, willing to characterize interstitial lung disease. For the dimensionality reduction and feature extraction, an algorithm based on Self-Organizing Maps (SOM) was implemented, with some variations, getting a reduction of about 3 million pixels that it composes an image, for 240 elements. For the pattern classification, a Multilayer Perceptron (MLP) was used, validated with the leave-one-out methodology. With a database containing 79 samples of linear pattern, 37 samples of nodular pattern, 30 samples of mixed pattern, and 72 samples of normal pattern, the classifier provided an average result of 89.5% of right classification, with 100% of right classification for linear pattern, 67.5% for nodular pattern, 63.3% for mixed pattern, and 100% for normal pattern. The results prove the validity of the methodology.
88

Estudo do remodelamento ativo da matriz extracelular pulmonar na esclerose sistêmica / Study of active pulmonary matrix remodeling process in systemic sclerosis

Erika Franco de Carvalho 11 February 2008 (has links)
Introdução: A doença intersticial pulmonar é um importante fator prognóstico na esclerose sistêmica (ES). O prognóstico das pneumonias intersticiais não específicas (NSIP) associadas às colagenoses tem sido descrito como melhor do que o da forma idiopática. Levanta-se a hipótese de que o processo de remodelamento e reparo do parênquima pulmonar nessas duas formas da doença sejam diferentes. Objetivos: Comparar os mecanismos de reparo e remodelamento entre a NSIP associada a ES e a NSIP idiopática. Observar o impacto dos mesmos nas provas de função pulmonar e na sobrevida. Métodos: Foram analisadas 40 biópsias de pacientes com o diagnóstico de NSIP (18 biópsias de NSIP associada a ES e 22 na forma idiopática). As informações clínicas e as provas de função pulmonar foram obtidas através da revisão dos prontuários. As lâminas foram revisadas por três patologistas. Foram comparadas as densidades epitelial, vascular, bem como a atividade vascular dos dois grupos utilizando o método de imuno-histoquímica. Para isso foram utilizados os anticorpos anti- citoqueratina 7 (CK-7), anti- proteína-a do surfactante (SP-A), antimarcador de célula endotelial CD-34 (CD34), e anti-molécula da adesão vascular 1 (VCAM-1). Também foi comparado o padrão de remodelamento da matriz septal e vascular, usando os métodos histoquímicos da resorcina (fibras elásticas) e picrosírius (colágeno). Uma análise estatística foi realizada comparando os resultados dos dois grupos, o impacto do remodelamento nas provas de função pulmonar e a influência na sobrevida. Resultados: A densidade das células epiteliais foi menor na NSIP-ES, do que na forma idiopática (p<0,0001). Já os pneumócitos tipo II e as células de Clara encontraram-se diminuídos no grupo idiopático (p=0,02). Uma diminuição na densidade vascular foi encontrada na NSIP-ES quando comparada à forma idiopática (p<0,0001); no entanto, a atividade vascular medida pelo VCAM-1 foi maior no grupo da NSIP-ES (p<0.0001). O conteúdo das fibras elásticas e colágeno septal, bem como o das fibras elásticas na parede vascular, estavam aumentados no grupo da ES quando comparados à forma idiopática (p=0,01; p=0,001 e p<0,0001, respectivamente). Não houve diferença estatística entre o colágeno da parede vascular, no grau de obstrução vascular ou associação entre os parâmetros de remodelamento e reparo do parênquima pulmonar na sobrevida dos dois grupos. Dentre as provas de função pulmonar, a DCO/Hb foi mais afetada no grupo da ES (59% do valor predito na ES e 97% no grupo idiopático). Foi observada uma associação direta entre a densidade vascular e a DCO/Hb (p=0,02). Após o seguimento de 36 meses, não foi observada diferença no prognóstico dos dois grupos. Conclusão: Os processos de remodelamento e reparo do parênquima pulmonar parecem ser diferentes entre os dois grupos. Apesar de o processo fibrótico ser mais intenso na NSIP-ES, isso parece não estar associado a um pior prognóstico, como tem sido descrito na forma idiopática. Como o processo de elastose e a expressão do VCAM-I são mais intensos na ES, isso sugere que o processo inflamatório tem um papel mais importante na patogênese e no processo de remodelamento e reparo da ES do que na forma idiopática. No entanto, outros estudos são necessários para validar a importância desses resultados e sua utilização para fins terapêuticos e de prognóstico / Background: The presence of Interstitial lung disease is a well recognized prognostic factor in systemic sclerosis (SSc). As the prognosis in nonspecific interstitial pneumonia (NSIP) has been described to be better in collagen vascular disorders compared to the idiopathic forms, it is conceivable that the mechanisms of repair and remodeling are different between these two forms of the disease. Objectives: To compare the mechanisms of repair and remodeling between SSc associated nonspecific pneumonia and the idiopathic form, as well as their impact on pulmonary function tests and survival rates. Methods: Biopsies from 18 patients with SSc-associated NSIP and 22 with idiopathic NSIP were analyzed. Clinical data and pulmonary function test results were obtained by retrospective chart review. All H&E slides were reviewed by three pathologists. The epithelial and vascular densities and vascular activity were compared between the two groups by immunohistochemistry with antibodies directed against cytokeratin-7, surfactant protein-a, CD34, and VCAM-1, as well as septal and vascular matrix remodeling using histochemical stains (picrosirius and resorcin). Statistical analyses were performed to compare the results of these various studies with clinical parameters (e.g. pulmonary function tests) and survival between the groups. Results: Epithelial cell density was lower in SSc-NSIP when compared with idiopathic-NSIP (p<0.0001). Type II pneumocytes and Clara cells were reduced in idiopathic NSIP (p=0.02). A decrease in microvessel density was found in SSc-NSIP compared to idiopathic-NSIP (p<0.0001). The vascular activity measured by VCAM-1 expression was higher in NSIP-SSc when compared to the idiopathic group (p<0.0001). A direct association between vascular density and DLCO/HB was found (p=0.02). Among pulmonary function tests the DLCO/HB was affected to a greater extent in the SSc group (59% of the predicted value in SSc and 97% in the idiopatic group). The content of septal collagen and elastic fibers, as well as the elastic fibers in the vascular wall, were higher in the SSc group (p=0.01, p=0.001 and p<0.0001, respectively). There were no differences in the collagen content of the vascular wall, vascular grade, or survival between the two groups. There was no difference in the survival rate between the two groups after a follow-up of 36 months. Conclusions: Alterations in the pulmonary epithelium and vasculature seem to differ in the SSc-NSIP when compared to the idiopathic form of the disease. Although the fibrotic process is more intense in the SSc group, it does not seem to affect the prognosis of these patients, contrary to what has been described in idiopatic lung fibrosis. Because the elastotic process and VCAM-1 expression are higher in the SSc group, this might suggest that inflammatory mechanisms affecting the elastic fiber system and vasculature could play a greater role in the pathogenesis and pulmonary remodeling process of SSc-NSIP than in idiopathic-NSIP. Further studies may be required to assess the significance of these findings and explore if they can provide prognostic and/or treatment information
89

Estudo do remodelamento ativo da matriz extracelular pulmonar na esclerose sistêmica / Study of active pulmonary matrix remodeling process in systemic sclerosis

Carvalho, Erika Franco de 11 February 2008 (has links)
Introdução: A doença intersticial pulmonar é um importante fator prognóstico na esclerose sistêmica (ES). O prognóstico das pneumonias intersticiais não específicas (NSIP) associadas às colagenoses tem sido descrito como melhor do que o da forma idiopática. Levanta-se a hipótese de que o processo de remodelamento e reparo do parênquima pulmonar nessas duas formas da doença sejam diferentes. Objetivos: Comparar os mecanismos de reparo e remodelamento entre a NSIP associada a ES e a NSIP idiopática. Observar o impacto dos mesmos nas provas de função pulmonar e na sobrevida. Métodos: Foram analisadas 40 biópsias de pacientes com o diagnóstico de NSIP (18 biópsias de NSIP associada a ES e 22 na forma idiopática). As informações clínicas e as provas de função pulmonar foram obtidas através da revisão dos prontuários. As lâminas foram revisadas por três patologistas. Foram comparadas as densidades epitelial, vascular, bem como a atividade vascular dos dois grupos utilizando o método de imuno-histoquímica. Para isso foram utilizados os anticorpos anti- citoqueratina 7 (CK-7), anti- proteína-a do surfactante (SP-A), antimarcador de célula endotelial CD-34 (CD34), e anti-molécula da adesão vascular 1 (VCAM-1). Também foi comparado o padrão de remodelamento da matriz septal e vascular, usando os métodos histoquímicos da resorcina (fibras elásticas) e picrosírius (colágeno). Uma análise estatística foi realizada comparando os resultados dos dois grupos, o impacto do remodelamento nas provas de função pulmonar e a influência na sobrevida. Resultados: A densidade das células epiteliais foi menor na NSIP-ES, do que na forma idiopática (p<0,0001). Já os pneumócitos tipo II e as células de Clara encontraram-se diminuídos no grupo idiopático (p=0,02). Uma diminuição na densidade vascular foi encontrada na NSIP-ES quando comparada à forma idiopática (p<0,0001); no entanto, a atividade vascular medida pelo VCAM-1 foi maior no grupo da NSIP-ES (p<0.0001). O conteúdo das fibras elásticas e colágeno septal, bem como o das fibras elásticas na parede vascular, estavam aumentados no grupo da ES quando comparados à forma idiopática (p=0,01; p=0,001 e p<0,0001, respectivamente). Não houve diferença estatística entre o colágeno da parede vascular, no grau de obstrução vascular ou associação entre os parâmetros de remodelamento e reparo do parênquima pulmonar na sobrevida dos dois grupos. Dentre as provas de função pulmonar, a DCO/Hb foi mais afetada no grupo da ES (59% do valor predito na ES e 97% no grupo idiopático). Foi observada uma associação direta entre a densidade vascular e a DCO/Hb (p=0,02). Após o seguimento de 36 meses, não foi observada diferença no prognóstico dos dois grupos. Conclusão: Os processos de remodelamento e reparo do parênquima pulmonar parecem ser diferentes entre os dois grupos. Apesar de o processo fibrótico ser mais intenso na NSIP-ES, isso parece não estar associado a um pior prognóstico, como tem sido descrito na forma idiopática. Como o processo de elastose e a expressão do VCAM-I são mais intensos na ES, isso sugere que o processo inflamatório tem um papel mais importante na patogênese e no processo de remodelamento e reparo da ES do que na forma idiopática. No entanto, outros estudos são necessários para validar a importância desses resultados e sua utilização para fins terapêuticos e de prognóstico / Background: The presence of Interstitial lung disease is a well recognized prognostic factor in systemic sclerosis (SSc). As the prognosis in nonspecific interstitial pneumonia (NSIP) has been described to be better in collagen vascular disorders compared to the idiopathic forms, it is conceivable that the mechanisms of repair and remodeling are different between these two forms of the disease. Objectives: To compare the mechanisms of repair and remodeling between SSc associated nonspecific pneumonia and the idiopathic form, as well as their impact on pulmonary function tests and survival rates. Methods: Biopsies from 18 patients with SSc-associated NSIP and 22 with idiopathic NSIP were analyzed. Clinical data and pulmonary function test results were obtained by retrospective chart review. All H&E slides were reviewed by three pathologists. The epithelial and vascular densities and vascular activity were compared between the two groups by immunohistochemistry with antibodies directed against cytokeratin-7, surfactant protein-a, CD34, and VCAM-1, as well as septal and vascular matrix remodeling using histochemical stains (picrosirius and resorcin). Statistical analyses were performed to compare the results of these various studies with clinical parameters (e.g. pulmonary function tests) and survival between the groups. Results: Epithelial cell density was lower in SSc-NSIP when compared with idiopathic-NSIP (p<0.0001). Type II pneumocytes and Clara cells were reduced in idiopathic NSIP (p=0.02). A decrease in microvessel density was found in SSc-NSIP compared to idiopathic-NSIP (p<0.0001). The vascular activity measured by VCAM-1 expression was higher in NSIP-SSc when compared to the idiopathic group (p<0.0001). A direct association between vascular density and DLCO/HB was found (p=0.02). Among pulmonary function tests the DLCO/HB was affected to a greater extent in the SSc group (59% of the predicted value in SSc and 97% in the idiopatic group). The content of septal collagen and elastic fibers, as well as the elastic fibers in the vascular wall, were higher in the SSc group (p=0.01, p=0.001 and p<0.0001, respectively). There were no differences in the collagen content of the vascular wall, vascular grade, or survival between the two groups. There was no difference in the survival rate between the two groups after a follow-up of 36 months. Conclusions: Alterations in the pulmonary epithelium and vasculature seem to differ in the SSc-NSIP when compared to the idiopathic form of the disease. Although the fibrotic process is more intense in the SSc group, it does not seem to affect the prognosis of these patients, contrary to what has been described in idiopatic lung fibrosis. Because the elastotic process and VCAM-1 expression are higher in the SSc group, this might suggest that inflammatory mechanisms affecting the elastic fiber system and vasculature could play a greater role in the pathogenesis and pulmonary remodeling process of SSc-NSIP than in idiopathic-NSIP. Further studies may be required to assess the significance of these findings and explore if they can provide prognostic and/or treatment information
90

Systemic sclerosis : vascular, pulmonary and immunological aspects

Neumann Andersen, Grethe January 2008 (has links)
In systemic sclerosis (SSc), interstitial lung disease (ILD) and engagement of the vascular system lead to increased morbidity and mortality. The aim of this thesis was to elucidate, in a consecutively included cohort of SSc (limited and diffuse) patients (n = 33), the T cell cytokine profile driving the disease in ILD and to explore the role of matrix metalloproteinase 9 (MMP-9) and its inhibitor: tissue inhibitor of metalloproteinase 1 (TIMP-1) in the extracellular matrix (ECM) degrading process leading to fibrous scarring and honey combing. Moreover, to characterize the role of nitric oxide (NO) in vascular engagement. Peripheral arterial changes cause Raynaud’s phenomenon and digital ulcers. Nitric oxide (NO) a main inducer of vasodilation is produced by endothelial nitric oxide synthase (eNOS) in response to changes in blood flow or by inflammatory cytokine inducible (i) NOS. In the vascular smooth muscle cell (VSMC) NO activates guanylate cyclase to produce cGMP, causing relaxation. We showed elevated plasma nitrate, a degradation product of NO, and increased urinary excretion of nitrate and cGMP. Plasma nitrate correlated with elevated levels of endothelial adhesion molecules: endothelial (E) selectin and vascular adhesion molecule 1, indicating that the activated endothelium is the site of NO synthesis by iNOS. Endothelial staining for E-selectin and the finding of iNOS and eNOS in SSc skin biopsies supported this notion. In SSc increased vascular stiffness may limit the NO vasodilatory effects. We found normal endothelium-dependent (i.e. flow mediated (FMD%)) and endothelium-independent (i.e. nitroglycerin-induced (NTG%)) vasodilation in the brachial artery. Radial arterial wall stiffness measured as maximum increase in pulse pressure (dP/dtmax) was increased. FMD% and especially NTG% correlated negatively and dP/dtmax positively to measures of endothelial inflammation: plasma- nitrate and adhesion molecule levels. Thus inflammatory vascular wall changes may interfere with dilation as may the presence of nitrate tolerance. We found elevated alveolar MMP-9 in both its pro- and active form in ILD. The levels correlated to decline in lung capacity, pointing at a causal relation. We suggest that neutrophils secrete MMP-9, which may degrade collagen IV, (the main constituent of basal membranes), collagen V, gelatins, proteoglycans and elastin. MMP-9 activity is partly regulated by the binding of pro- and active form to TIMP-1. Alveolar TIMP-1, which even stimulates fibroblast ECM synthesis, was increased independent of ILD. The inflammatory process in ILD is orchestrated by activated T helper (h) lymphocytes. We found a mixed Th1/Th2 reaction in SSc alveolar T cells expressing messenger for interferon gamma (Th1), IL-6 and IL-10 (both Th2). No particular cytokine mRNA profile distinguished alveolar T cells in ILD. Neutrophils invaded the bronchial epithelium, which seemed otherwise inert as levels of inflammatory cytokine sensitive transcription factors and their nuclear translocation tended to be low. The neutrophil recruitment pathway is uncertain as chemoattractants and endothelial adhesion molecules were normally expressed. In conclusion, MMP-9 probably causes degradation of lung tissue in ILD and may represent a future therapeutic target. Alveolar T cells show a mixed Th1/Th2 cytokine profile independent of ILD. Neutrophils invade the bronchial epithelium. Activated endothelium produces increased amounts of NO and adhesion molecules and the level of activation influences brachial arterial FMD% and NTG% and radial arterial compliance. Nitrate tolerance may be present.

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