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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.
1

Mechanisms of Airway Remodelling

Boustany, Sarah January 2008 (has links)
Doctor of Philosophy (PhD) / Asthma is an inflammatory disease characterised by tissue remodelling. A prominent feature of this remodelling is an increase in the number and size of the blood vessels- formed from pre-existing capillaries – angiogenesis (Siddiqui et al., 2007; Wilson, 2003). This is triggered by many different endogenous angiogenic stimulators such as vascular endothelial growth factor (VEGF), and inhibited by endogenous angiogenic inhibitors such as tumstatin. Tumstatin is the non-collagenous domain (NC1) of the collagen IV α3 chain which, when cleaved, inhibits endothelial cell proliferation and induces apoptosis. Experiments described in this thesis have for the first time demonstrated the absence of tumstatin in the airways of individuals with asthma and lymphangioleiomyomatosis (LAM) as well as the functional responses to tumstatin as an angiogenic inhibitor, both in vitro and in vivo, in the airway. Although tumstatin was absent from the airways of asthmatic and LAM individuals it was present in the airways of individuals with no airways disease, chronic obstructive pulmonary disease, bronchiectasis and cystic fibrosis. No significant difference was seen in the levels of the Goodpasture Binding Protein (GPBP), a phosphorylating protein responsible for the alternate folding of tumstatin, between asthmatic, LAM and individuals with no airways disease. The αvβ3 integrin, reported to be necessary for the activity of tumstatin, as well as the individual αv and β3 sub-units were shown to be equally expressed in the airways of all patient groups. Co-localisation of tumstatin, VEGF and the αvβ3 integrin was seen in the disease free airways, however, a different pattern of VEGF and the αvβ3 integrin expression was observed in asthmatic and LAM airways with minimal co-localisation. Tumstatin was detected in serum and bronchoalveolar lavage fluid (BAL-f) samples from asthmatics and individuals with no airway disease, however there was no significant difference in the level of expression between the two groups. It was demonstrated that the tumstatin detected in the serum and BAL-f samples from asthmatics and individuals with no airway disease was part of the whole collagen IV α3 chain and not in its free and potentially active form. The ability of recombinant tumstatin to inhibit tube formation and proliferation of primary pulmonary endothelial cells was demonstrated for the first time. Further, the functional response of tumstatin was demonstrated in vivo in a mouse model of allergic airway disease. Tumstatin inhibited angiogenesis in the airway and decreased airway hyperresponsiveness. Whether there is potential for tumstatin, or a derivative thereof, to be of therapeutic value in airways diseases in which angiogenesis is a component should be the subject of future studies.
2

Mechanisms of Airway Remodelling

Boustany, Sarah January 2008 (has links)
Doctor of Philosophy (PhD) / Asthma is an inflammatory disease characterised by tissue remodelling. A prominent feature of this remodelling is an increase in the number and size of the blood vessels- formed from pre-existing capillaries – angiogenesis (Siddiqui et al., 2007; Wilson, 2003). This is triggered by many different endogenous angiogenic stimulators such as vascular endothelial growth factor (VEGF), and inhibited by endogenous angiogenic inhibitors such as tumstatin. Tumstatin is the non-collagenous domain (NC1) of the collagen IV α3 chain which, when cleaved, inhibits endothelial cell proliferation and induces apoptosis. Experiments described in this thesis have for the first time demonstrated the absence of tumstatin in the airways of individuals with asthma and lymphangioleiomyomatosis (LAM) as well as the functional responses to tumstatin as an angiogenic inhibitor, both in vitro and in vivo, in the airway. Although tumstatin was absent from the airways of asthmatic and LAM individuals it was present in the airways of individuals with no airways disease, chronic obstructive pulmonary disease, bronchiectasis and cystic fibrosis. No significant difference was seen in the levels of the Goodpasture Binding Protein (GPBP), a phosphorylating protein responsible for the alternate folding of tumstatin, between asthmatic, LAM and individuals with no airways disease. The αvβ3 integrin, reported to be necessary for the activity of tumstatin, as well as the individual αv and β3 sub-units were shown to be equally expressed in the airways of all patient groups. Co-localisation of tumstatin, VEGF and the αvβ3 integrin was seen in the disease free airways, however, a different pattern of VEGF and the αvβ3 integrin expression was observed in asthmatic and LAM airways with minimal co-localisation. Tumstatin was detected in serum and bronchoalveolar lavage fluid (BAL-f) samples from asthmatics and individuals with no airway disease, however there was no significant difference in the level of expression between the two groups. It was demonstrated that the tumstatin detected in the serum and BAL-f samples from asthmatics and individuals with no airway disease was part of the whole collagen IV α3 chain and not in its free and potentially active form. The ability of recombinant tumstatin to inhibit tube formation and proliferation of primary pulmonary endothelial cells was demonstrated for the first time. Further, the functional response of tumstatin was demonstrated in vivo in a mouse model of allergic airway disease. Tumstatin inhibited angiogenesis in the airway and decreased airway hyperresponsiveness. Whether there is potential for tumstatin, or a derivative thereof, to be of therapeutic value in airways diseases in which angiogenesis is a component should be the subject of future studies.
3

Tomografia quantitativa de tórax: comparações entre asmáticos de difícil controle, asmáticos bem controlados e indivíduos sem doença respiratória e correlações com parâmetros espirométricos / Thoracic quantitative computed tomography: comparisons between difficult-to-treat asthmatic patients, controlled asthmatic patients and subjects without respiratory diseases and correlations with spirometry

Silva, Izabela Maria Elias 03 June 2019 (has links)
A asma é uma doença crônica das vias aéreas, cuja fisiopatologia compreende inflamação, hiper-responsividade e remodelação. As características clínicas e a espirometria são usadas para avaliar o controle da doença. Alguns asmáticos não conseguem controlar tomando altas doses de medicações de controle (asma de difícil controle). A tomografia computadorizada quantitativa de tórax (TCQ) é pouco usada na asma, mas pode fornecer biomarcadores da doença. Objetivos: Comparar os achados de TCQ de indivíduos sem doenças respiratórias (grupo controle - GC), com asma controlada (ABC) e com asma de difícil controle (ADC), visando prioritariamente parâmetros substitutivos do remodelamento das vias aéreas. Investigar se há correlações entre os parâmetros QCT e espirometria. Materiais e Métodos: Recrutamos sujeitos com ADC e ABC em um hospital terciário. Usamos registros médicos e convite pessoal para obter dados de CG. Todos os indivíduos foram submetidos a tomografia computadorizada de alta resolução e espirometria. Um software (Yacta) foi usado para obter dados de TCQ. O teste t de Student, o one-way ANOVA e o teste exato de Fisher foram realizados para comparar os dados dos grupos. Os coeficientes de correlação de Pearson foram calculados para avaliar as correlações entre os parâmetros espirométricos e TCQ. Resultados: O GC foi composto por 21 sujeitos; ABC, de 28 e ADC, de 27. Estes últimos eram mais idosos que GC e ABC (50,85 (10,11); 41,27 (11,57); 42,04 (10,11) anos; p = 0,002). A espessura relativa das vias aéreas (ERP3-8) foi significativamente diferente entre GC e ADC (45,31% (3,71); 49,38% (3,38); p = 0,001) e entre GC e ABC (45,31%, 71); 48,25 (4,51); p = 0,001). A espessura normalizada das vias aéreas (Pi10) foi significativamente diferente entre ADC e ABC (0,51 (0,10); 0,44 (0,10); p = 0,0001) e entre ADC e CG (0,51 (0,10), 0,39 (0,08), p = 0,0001). A área da parede das vias aéreas (AP/ASC-mm2) da terceira geração brônquica foi significativamente diferente entre o ADC e o GC (37,14 (9,70); 30,18 (5,06); p = 0,005) e entre ABC e GC (35, 54 (6,37); 30,18 (5,06); p = 0,005). A área da luz da via aérea da terceira geração brônquica (LA/ASC-mm2) foi significativamente diferente entre ADC e ABC (28,81 (10,08); 35,88 (7,12); p = 0,002) e entre ADC e GC (28 81 (10,08); 36,14 (7,29); p = 0,002). A atenuação máxima média (MMA-Hounsfield Units) da terceira geração brônquica foi significativamente diferente entre ADC e GC (-128,68 (67,15); -232,01 (75,20); p = 0,0001) e entre ABC e CG (-147,81 (75,31); -232,01 (75,20); p = 0,0001). Encontramos correlações negativas entre o volume expiratório forçado no primeiro segundo (VEF1) e a ERP na terceira, quarta e quinta gerações brônquicas; entre o índice Tiffeneau e a ERP nessas gerações; entre fluxo expiratório forçado (FEF25-75%) e ERP nas mesmas gerações. Encontramos correlações negativas entre VEF1 e AMMna terceira e quarta gerações e entre o índice de Tiffeneau e AMM nessas gerações. Encontramos correlações negativas entre o FEF(25-75%) e o AMM nessas gerações. Conclusões: Mesmo os asmáticos com doença controlada apresentaram evidências radiológicas de comprometimento da parede das vias aéreas; as evidências foram maiores em asma de difícil controle. Características tomográficas podem ser devido a inflamação ou remodelação. Encontramos correlações entre os parâmetros espirométricos e TCQ. Nossos achados reforçam a utilidade potencial dos parâmetros do TCQ como biomarcadores do controle da asma e da resposta ao tratamento, em pesquisa e em bases clínicas / Asthma is a chronic airway disease whose pathophysiology comprises inflammation, hyperresponsivenes and remodelling. Clinical characteristics and spirometry are used to assess disease control. Some asthmatics do not achieve control taking high doses of controller therapy (difficult to control asthma). Quantitative lung computed tomography (QCT) is seldom used in asthma but may provide asthma biomarkers. Objectives: To compare QCT findings of subjects without respiratory diseases (control group - CG), with controlled asthma (CA) and with difficult to control asthma (DCA), aiming primarily at surrogate parameters of airway remodelling. To investigate whether there are correlations between QCT and spirometry parameters. Materials and Methods: We recruited subjects with DCA and CA from a tertiary hospital. We used medical records and personal invitation to obtain CG data. All subjects underwent high resolution computed tomography and spirometry. A software (Yacta) was used to obtain QCT data. Student\'s t-test, one-way ANOVA and Fisher\'s exact test were performed to compare data from the groups. Pearson correlation coefficients were calculated to assess correlations between spirometric and QTC parameters. Results: The CG was comprised of 21 subjects; CA, of 28 and DCA, of 27. The latter had older subjects than CG and CA (50,85 (10,11); 41,27 (11,57); 42,04 (10,11) years; p=0,002). Relative airway thickness (RT) was significantly different between CG and DCA (45,31% (3,71); 49,38% (3,38); p=0,001) and between CG and CA (45,31% (3,71); 48,25 (4,51); p=0,001). Normalised airway thickness (Pi10) were significantly different between DCA and CA (0,51 (0,10); 0,44 (0,10); p=0,0001) and between DCA and CG (0,51 (0,10); 0,39 (0,08); p=0,0001). Airway wall area (AWAmm2) of the third bronchial generation was significantly different between DCA and CG (37,14 (9,70); 30,18 (5,06); p=0,005) and between CA and CG (35,54 (6,37); 30,18 (5,06); p=0,005). Airway lumen area of the third bronchial generation (ALA-mm2) was significantly different between DCA and CA (28,81 (10,08); 35,88 (7,12); p=0,002) and between DCA and CG (28,81 (10,08); 36,14 (7,29); p=0,002). Mean maximum attenuation (MMA-Hounsfield Units) of the third bronchial generation was significantly different between DCA and CG (-128,68 (67,15); -232,01 (75,20); p=0,0001) and between CA and CG (-147,81 (75,31); -232,01 (75,20); p=0,0001). We found negative correlations between forced expiratory volume on the first second (FEV1) and RT on the third, fourth and fifth bronchial generations ; between the Tiffeneau index and RT on those generations; between forced expiratory flow (FEF25-75) and RT on the same generations. We found negative correlations between FEV1 and MMA on the third and fourth generations and between the Tiffeneau index and MMA on those geneations. We found negative correlations between FEF25-75 and MMA on those generations.Conclusions: Even asthmatics with controlled disease had radiological evidence of airway wall involvement; the evidences were greater in difficult to control asthma. Tomographic features can be due to inflammation or remodelling. We found correlations between spirometric and QTC parameters. Our findings reinforce the potential usefulness of QTC parameters as biomarkers of asthma control and of response to treatment, on research and clinical grounds
4

Distribuição de colágeno na concha nasal inferior de pacientes com rinite alérgica ou idiopática / Collagen distribution in the inferior nasal concha in patients with allergic or idiophatic rhinitis

Salgado, Daniel Cauduro 22 October 2014 (has links)
INTRODUÇÃO: Embora seja reconhecida a existência do espessamento da membrana basal e da fibrose da concha nasal na rinite alérgica, não há estudos descritivos do comportamento da mucosa nasal nos pacientes com rinite idiopática. O propósito desse estudo é descrever possíveis alterações na membrana basal e na lâmina própria da concha nasal inferior em pacientes com rinite alérgica ou idiopática, além do estudo quantitativo das fibras colágenas nesta localização. MÉTODOS: Analisou-se na concha nasal inferior obtida através de turbinectomia bilateral em 28 pacientes - 14 com rinite alérgica e 14 com rinite idiopática - a área ocupada pelo colágeno, a espessura da membrana basal e o diâmetro das fibrilas de colágeno através do uso de microscopia óptica (coloração Hematoxilina-eosina e Picrossírius-hematoxilina), microscopia eletrônica e imunoistoquímica para laminina e colágeno IV. RESULTADOS: 1) pacientes com rinite alérgica apresentaram significantemente maior área da concha nasal ocupada por colágeno do que o grupo com rinite idiopática. 2) a membrana basal de pacientes com rinite alérgica foi significantemente mais espessa. 3) a lâmina reticular da membrana basal dos pacientes com rinite alérgica apresentaram fibrilas de colágeno com menor diâmetro que os pacientes com rinite idiopática. 4) não houve diferenças significativas entre os grupos na distribuição de laminina e de colágeno IV. CONCLUSÕES: Alterações na mucosa nasal ocorrem na rinite alérgica, sendo caracterizadas pelo aumento da espessura da membrana basal e por fibrose. Na rinite idiopática, observou-se uma mucosa com aspecto estrutural semelhante aos pacientes normais / INTRODUCTION: Despite our knowledge about nasal conchae fibrosis and basement membrane thickening in allergic rhinitis, there are no descriptive studies on nasal mucosa behavior in patients with idiopathic rhinitis. The aim of our study was to describe possible changes in the basement membrane and lamina propria of the inferior concha in patients with idiopathic or allergic rhinitis, in addition to a quantitative study of collagen fibers in this site. METHODS: The inferior nasal concha obtained from 28 patients submitted to bilateral turbinectomy was examined - 14 with allergic rhinitis and 14 with idiopathic rhinitis; analyzing the collagen area, the basement membrane thickness and the collagen fibrils diameter using optical microscopy (Hematoxylin-eosin and Picrosirius-hematoxylin staining), electron microscopy and immunohistochemistry for laminin and collagen IV. RESULTS: 1) patients with allergic rhinitis had a significantly larger area of the nasal concha occupied by collagen than the group with idiopathic rhinitis. 2) the basement membrane of patients with allergic rhinitis was significantly thicker. 3) the reticular lamina of the basement membrane of patients with allergic rhinitis had collagen fibrils with diameters which were smaller than those from patients with idiopathic rhinitis. 4) there were no significant differences between the groups concerning the distribution of laminin and collagen IV. CONCLUSIONS: Alterations to the nasal mucosa that happen in allergic rhinitis are characterized by basement membrane thickening and fibrosis. In idiopathic rhinitis the patients\' mucosae were structurally similar to those from normal patients
5

Distribuição de colágeno na concha nasal inferior de pacientes com rinite alérgica ou idiopática / Collagen distribution in the inferior nasal concha in patients with allergic or idiophatic rhinitis

Daniel Cauduro Salgado 22 October 2014 (has links)
INTRODUÇÃO: Embora seja reconhecida a existência do espessamento da membrana basal e da fibrose da concha nasal na rinite alérgica, não há estudos descritivos do comportamento da mucosa nasal nos pacientes com rinite idiopática. O propósito desse estudo é descrever possíveis alterações na membrana basal e na lâmina própria da concha nasal inferior em pacientes com rinite alérgica ou idiopática, além do estudo quantitativo das fibras colágenas nesta localização. MÉTODOS: Analisou-se na concha nasal inferior obtida através de turbinectomia bilateral em 28 pacientes - 14 com rinite alérgica e 14 com rinite idiopática - a área ocupada pelo colágeno, a espessura da membrana basal e o diâmetro das fibrilas de colágeno através do uso de microscopia óptica (coloração Hematoxilina-eosina e Picrossírius-hematoxilina), microscopia eletrônica e imunoistoquímica para laminina e colágeno IV. RESULTADOS: 1) pacientes com rinite alérgica apresentaram significantemente maior área da concha nasal ocupada por colágeno do que o grupo com rinite idiopática. 2) a membrana basal de pacientes com rinite alérgica foi significantemente mais espessa. 3) a lâmina reticular da membrana basal dos pacientes com rinite alérgica apresentaram fibrilas de colágeno com menor diâmetro que os pacientes com rinite idiopática. 4) não houve diferenças significativas entre os grupos na distribuição de laminina e de colágeno IV. CONCLUSÕES: Alterações na mucosa nasal ocorrem na rinite alérgica, sendo caracterizadas pelo aumento da espessura da membrana basal e por fibrose. Na rinite idiopática, observou-se uma mucosa com aspecto estrutural semelhante aos pacientes normais / INTRODUCTION: Despite our knowledge about nasal conchae fibrosis and basement membrane thickening in allergic rhinitis, there are no descriptive studies on nasal mucosa behavior in patients with idiopathic rhinitis. The aim of our study was to describe possible changes in the basement membrane and lamina propria of the inferior concha in patients with idiopathic or allergic rhinitis, in addition to a quantitative study of collagen fibers in this site. METHODS: The inferior nasal concha obtained from 28 patients submitted to bilateral turbinectomy was examined - 14 with allergic rhinitis and 14 with idiopathic rhinitis; analyzing the collagen area, the basement membrane thickness and the collagen fibrils diameter using optical microscopy (Hematoxylin-eosin and Picrosirius-hematoxylin staining), electron microscopy and immunohistochemistry for laminin and collagen IV. RESULTS: 1) patients with allergic rhinitis had a significantly larger area of the nasal concha occupied by collagen than the group with idiopathic rhinitis. 2) the basement membrane of patients with allergic rhinitis was significantly thicker. 3) the reticular lamina of the basement membrane of patients with allergic rhinitis had collagen fibrils with diameters which were smaller than those from patients with idiopathic rhinitis. 4) there were no significant differences between the groups concerning the distribution of laminin and collagen IV. CONCLUSIONS: Alterations to the nasal mucosa that happen in allergic rhinitis are characterized by basement membrane thickening and fibrosis. In idiopathic rhinitis the patients\' mucosae were structurally similar to those from normal patients
6

Étude du remodelage du muscle lisse bronchique chez les chevaux asthmatiques légers à modérés

Dupuis-Dowd, Florence 08 1900 (has links)
L’asthme équin est une condition inflammatoire fréquente affectant les voies respiratoires inférieures. Cette maladie est caractérisée par une bronchoconstriction, une hyperréactivité bronchique, ainsi que des changements des différentes couches tissulaires des voies respiratoires que l’on regroupe sous le terme de remodelage pulmonaire. Le remodelage du muscle lisse bronchique dans l’asthme comprend une hyperplasie, une hypertrophie, ainsi qu’une altération des propriétés contractiles des myocytes. Bien que ces changements aient été décrits dans la forme sévère de l’asthme équin, la présence de telles altérations chez les chevaux atteints des formes légères à modérées de l’asthme demeure incertaine. L’objectif de notre étude est donc de déterminer si le muscle lisse bronchique présente un remodelage chez les chevaux asthmatiques légers à modérés. Des biopsies endobronchiques provenant de 18 chevaux asthmatiques et de 7 chevaux contrôles ont été étudiées. Le diagnostic était basé sur les signes cliniques et confirmé par cytologie du lavage bronchoalvéolaire. La prolifération des cellules du muscle lisse bronchique était évaluée par l’expression du proliferating cell nuclear antigen marqué par immunohistochimie, et l’expression génique de l’isoforme rapide de la myosine, une protéine hypercontractile, a été mesurée par RT-qPCR. Cette étude a permis de mettre en évidence une surexpression de l’isoforme rapide de la myosine chez les chevaux asthmatiques légers à modérés. Malgré l’absence de différence dans le taux de prolifération cellulaire du muscle lisse bronchique entre les groupes, le pourcentage de myocytes en prolifération était corrélé à l’inflammation pulmonaire neutrophilique ainsi qu’à l’expression de l’isoforme rapide de la myosine chez les chevaux asthmatiques. Cette première étude évaluant le remodelage du muscle lisse bronchique chez les chevaux asthmatiques légers à modérés a démontré une altération fonctionnelle du muscle lisse bronchique dans les formes légères de l’asthme équin, une possible influence de la neutrophilie pulmonaire sur la prolifération du muscle lisse, ainsi qu’une association entre les phénotypes prolifératifs et contractiles. Les altérations identifiées pourraient servir de biomarqueurs potentiels dans l’évolution de la maladie et de la réponse aux traitements. / Equine asthma is a common inflammatory condition affecting the lower airways. This disease is characterised by bronchoconstriction, airway hyperreactivity, and changes in the different tissue layers of the airways, which are referred to as airway remodelling. Remodelling of the smooth muscle in asthma includes hyperplasia, hypertrophy, and altered contractile properties of the myocytes. Although these changes have been described in severe equine asthma, their presence in horses with milder forms of asthma remains unclear. The aim of our study was therefore to determine whether airway smooth muscle remodelling occurs in horses with mild to moderate asthma. Endobronchial biopsies from 18 asthmatic horses and 7 control horses were studied. The diagnosis was based on clinical signs and confirmed by bronchoalveolar lavage cytology results. Airway smooth muscle cell proliferation was assessed by the expression of immunohistochemically labelled proliferating cell nuclear antigen, and the gene expression of the fast contracting myosin isoform, a hypercontractile protein, was measured by RT-qPCR. This study showed overexpression of the fast contracting myosin isoform in horses with mild to moderate asthma. Although there was no difference in the proliferation rate of airway smooth muscle myocyte between groups, it was correlated with neutrophilic lung inflammation as well as with the expression of the fast myosin isoform in asthmatic horses. This first study evaluating airway smooth muscle remodelling in mild to moderate asthmatic horses has demonstrated a functional alteration of airway smooth muscle in mild equine asthma, as well as a possible influence of pulmonary neutrophilia on smooth muscle proliferation, and an association between proliferative and contractile phenotypes. The identified alterations could eventually serve as biomarkers in the evolution of the disease and the response to treatments.
7

Detekce časných patofyziologických změn dýchání u dětí s chronickým plicním onemocněním / Detection of early pathophysiological changes of breathing in children with chronic respiratory disease

Koucký, Václav January 2020 (has links)
Detection of early pathophysiological changes of breathing in children with chronic respiratory disease MD. Vaclav Koucky - Ph.D. thesis Abstract Introduction: Currently, there are different methods for infant pulmonary function testing (iPFT) and morphological assessment of microscopic changes in endobronchial biopsy samples (EBB). In research setting, they allow detection of early pathophysiological changes of breathing in small children with chronic respiratory disease, respectively in risk of its development. Their clinical significance, however, is not fully acknowledged. The aim of this thesis is to evaluate the safety, feasibility and clinical significance of iPFT and EBB in infants younger than 2 years of age. In addition, the relationship between functional and morphological changes of respiratory tract and the function of peripheral chemoreceptors was studied in selected patients' subgroups. Methods: Fifty-five infants with cystic fibrosis (CF), 35 physician-confirmed recurrent wheezers (AB), 9 infants with congenital diaphragmatic hernia, 7 with interstitial lung disease (chILD) and 3 with primary ciliary dyskinesia (PCD) were enrolled. All infants underwent iPFT and relevant clinical history data were recorded. Based on patients' age, CF group was divided into CFmalí (< 6 months) and CFvelcí (>...

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