As colectinas pulmonares SP-A e SP-D são marcadores específicos de doenças pulmonares. A determinação destas proteínas por ensaios imunoenzimáticos permite aos clínicos correlacionarem seu papel funcional durante o desenvolvimento do processo patológico baseado nas anormalidades de suas concentrações. Como o lavado broncoalveolar (BAL) é uma amostra que permite estudar as proteínas secretadas pelo epitélio pulmonar em quaisquer circunstâncias, foi proposto o desenvolvimento de um ELISA indireto capaz de detectar SP-A no BAL humano usando um anti-soro policlonal contra SP-A suína produzido em coelho. SP-A suína foi purificada por protocolo que acopla precipitação ácida do extrato pulmonar suíno e cromatografia de afinidade. O anti-soro reagiu com as duas espécies de SP-A testadas: humana e suína. A curva padrão foi otimizada utilizando como calibrador a SP-A purificada de pacientes com artrite reumatóide. A faixa selecionada da curva de calibração foi de 0,312 to 5,0 mg/mL usando a diluição 1:1000 do anticorpo. O limite de detecção da curva foi de 0,625 mg/mL. / The lung collectins SP-A and SP-D are specific markers for lung diseases. Determination of amounts of these proteins using polyclonal and monoclonal antibodies on ELISA assays enabled clinicians to predict their role in the course of the lung disease process based on abnormalities on their concentrations. As the bronchoalveolar lavage (BAL) is a sample that permits to study the proteins secreted by the lung epithelium at any conditions, we proposed to develop an indirect ELISA able to detect SP-A in the BAL using polyclonal rabbit antiserum, raised against porcine SP-A. Porcine SP-A was purified by a protocol that includes an acid precipitation of the porcine pulmonary extract before affinity chromatography. The antiserum reacted with the two tested species porcine and human. The calibration curve were optimized, using human SP-A purified from patients with rheumatoid arthritis as human antigen calibrator. The selected calibration curve range was 0.312 to 5.0 mg/mL using the antiboby dilution 1:1.000. The detection limit of the standard curve was 0.625 mg/mL.

Une croissance intra-utérine insuffisante représente, avec la prématurité et les malfor-mations congénitales, une des principales causes de morbidité et de mortalité néonatales. Ces pathologies sont liées entre elles, les nouveau-nés prématurés étant souvent atteints de RCIU (RCIU). Les études épidémiologiques récentes ont montré que le RCIU était associé à une augmentation de la morbidité respiratoire dès la période néonatale, avec, en particulier, une augmentation du risque de dysplasie broncho-pulmonaire (DBP), principale séquelle respira-toire de la prématurité. La DBP est caractérisée par des anomalies du développement alvéo-laire et vasculaire, considérées comme les conséquences d’agressions multiples sur un poumon immature. La physiopathologie exacte reste encore largement méconnue. Nous nous sommes intéressés dans ce travail au lien entre RCIU et DBP avec un abord expérimental et clinique. Alors que les études épidémiologiques sont relativement concordantes sur le lien entre RCIU et DBP, les études expérimentales, montrent des résultats divers tant sur le développement pulmonaire qu’au niveau moléculaire. Nous avons donc voulu identifier, dans un premier temps, un modèle de RCIU reproduisant les anomalies du développement alvéolaire observées chez l’Homme en utilisant trois modèles précédemment validés chez le rat : un modèle de res-triction protidique per-gestationnelle , un modèle de ligature unilatérale de l’artère utérine, un modèle d’injection d’un inhibiteur chimique de la NO synthase, le L NAME. Seule la restric-tion protidique anténatale permet de reproduire à long terme des lésions de l’alvéolisation proches de celles observées dans la DBP. En revanche, dans ce modèle, les modifications des principaux gènes identifiés précédemment dans les anomalies le développement alvéolaire ne sont pas observées, que ce soit avant, pendant ou après l’alvéolisation. Ce résultat nous a ame-né à entreprendre une étude multigénique qui a permis d’identifier plusieurs voies modifiées pendant l’alvéolisation dans ce modèle. Parmi celles-ci, les gènes impliqués dans la contractili-té et l’adhésion cellulaire, l’immunité ou la voie des « Peroxisome Proliferator-Activated Re-ceptor ». Dans la partie clinique de cette étude, nous avons évalué le risque de DBP chez les extrêmes prématurés atteints de RCIU dont les mères présentaient des signes de pathologie vasculaire de la grossesse (prééclampsie). Cette étude rétrospective unicentrique sur 184 en-fants a permis de comparer des enfants atteints de RCIU à des enfants eutrophes pris en charge de manière homogène. Le RCIU d’origine vasculaire multiplie le risque de DBP par 6. Un marqueur précoce de l’évolution vers une DBP est un taux de plaquettes bas à la naissance, évoquant le rôle d’un taux élevé de facteurs anti-angiogéniques circulants. Une étude est en cours pour corréler les facteurs anti-angiogéniques circulants présents chez les mères pré-éclamptiques au devenir respiratoire, en particulier à l’évolution vers une DBP, de leurs nou-veau-nés d’âge gestationnel inférieur à 30 semaines d’aménorrhée. En conclusion, nous avons montré expérimentalement que seule la restriction protidique anténatale chez le rat reproduisait les troubles de l’alvéolisation comparables à ceux observés dans la DBP. De nouvelles voies moléculaires potentiellement impliquées dans les anomalies de l’alvéolisation ont été mises en évidence. Par ailleurs, le rôle de facteurs anti-angiogéniques d’origine maternelle comme fac-teurs de développement d’une DBP est en cours d’évaluation. / Insufficient intrauterine growth is with prematurity and congenital malformations, a major cause of neonatal morbidity and mortality. These conditions are interrelated, the preterm infants often suffered of intrauterine growth restriction (IUGR). Recent epidemiological stud-ies showed that IUGR was associated with increased respiratory morbidity as soon as the ne-onatal period, with an increased risk of bronchopulmonary dysplasia (BPD), the main respira-tory sequelae of prematurity. BPD is characterized by impaired alveolar and vascular devel-opment and is the consequence of multiple insults on an immature lung. The exact pathophysi-ology is still largely unknown. We study in this work the relationship between IUGR and DBP with an experimental and clinical approach. While epidemiological studies are relatively concordant on the relationship between IUGR and BPD, experimental studies showed various results in lung development and molecular process. We wanted to identify, at first, a model of IUGR reproducing impaired alveolar development observed in humans using three previously validated models in rats: a model of per-gestational protein restriction, a model of unilateral ligation uterine artery, an injection pattern of a chemical inhibitor of NO synthase, L NAME. Only antenatal protein restriction can reproduce long-term impaired alveolarization as those observed in BPD. However, in this model, changes in key genes previously identified in pathological alveolar development are not observed before, during or after alveolarization. This result led us to perform a genome-wide analysis which identified several modified path-ways during alveolarization. Among these, the genes involved in the “cardiac contractility”, “cell adhesion molecules”, “immunity”, “molecular adhesion” or the "Peroxisome Proliferator-Activated Receptor" pathways. In the clinical part of this study, we evaluated the risk of BPD in extreme preterm infants with IUGR whose mothers had evidence of vascular disease of pregnancy (preeclampsia). This single-center retrospective study of 184 children was used to compare children with IUGR in adjusted for gestational age children. The vascular IUGR increases the risk of DBP by 6. An early marker of progression to BPD is a low platelet count at birth, referring to the role of high levels of circulating anti-angiogenic factors. A study is ongoing to correlate circulating anti-angiogenic factors present in preeclamptic mothers to res-piratory outcome and particularly BDP, in newborn younger than 30 weeks of gestational age at birth. In conclusion, we have shown experimentally that only prenatal protein restriction in rats reproduced impaired alveolarization comparable to those observed in the BPD. New mo-lecular pathways potentially involved in the impaired alveolarization were highlighted. More-over, the role of placental anti-angiogenic factors leading to development of BPD is evaluat-ed.

As colectinas pulmonares SP-A e SP-D são marcadores específicos de doenças pulmonares. A determinação destas proteínas por ensaios imunoenzimáticos permite aos clínicos correlacionarem seu papel funcional durante o desenvolvimento do processo patológico baseado nas anormalidades de suas concentrações. Como o lavado broncoalveolar (BAL) é uma amostra que permite estudar as proteínas secretadas pelo epitélio pulmonar em quaisquer circunstâncias, foi proposto o desenvolvimento de um ELISA indireto capaz de detectar SP-A no BAL humano usando um anti-soro policlonal contra SP-A suína produzido em coelho. SP-A suína foi purificada por protocolo que acopla precipitação ácida do extrato pulmonar suíno e cromatografia de afinidade. O anti-soro reagiu com as duas espécies de SP-A testadas: humana e suína. A curva padrão foi otimizada utilizando como calibrador a SP-A purificada de pacientes com artrite reumatóide. A faixa selecionada da curva de calibração foi de 0,312 to 5,0 mg/mL usando a diluição 1:1000 do anticorpo. O limite de detecção da curva foi de 0,625 mg/mL. / The lung collectins SP-A and SP-D are specific markers for lung diseases. Determination of amounts of these proteins using polyclonal and monoclonal antibodies on ELISA assays enabled clinicians to predict their role in the course of the lung disease process based on abnormalities on their concentrations. As the bronchoalveolar lavage (BAL) is a sample that permits to study the proteins secreted by the lung epithelium at any conditions, we proposed to develop an indirect ELISA able to detect SP-A in the BAL using polyclonal rabbit antiserum, raised against porcine SP-A. Porcine SP-A was purified by a protocol that includes an acid precipitation of the porcine pulmonary extract before affinity chromatography. The antiserum reacted with the two tested species porcine and human. The calibration curve were optimized, using human SP-A purified from patients with rheumatoid arthritis as human antigen calibrator. The selected calibration curve range was 0.312 to 5.0 mg/mL using the antiboby dilution 1:1.000. The detection limit of the standard curve was 0.625 mg/mL.

Cette recherche vise à développer un système de diagnostic assisté par ordinateur pour la détection automatique et la classification des pathologies du parenchyme pulmonaire telles que les pneumonies interstitielles idiopathiques et l'emphysème, en tomodensitométrie multicoupe. L’approche proposée repose sur morphologie mathématique 3-D, analyse de texture et logique floue, et peut être divisée en quatre étapes : (1) un schéma de décomposition multi-résolution basé sur un filtre 3-D morphologique exploitée pour discriminer les régions pulmonaires selon différentes échelles d’analyse. (2) Un partitionnement spatial supplémentaire du poumon basé sur la texture du tissu pulmonaire a été introduit afin de renforcer la séparation spatiale entre les motifs extraits au même niveau résolution dans la pyramide de décomposition. Puis, (3) une structure d'arbre hiérarchique a été construite pour décrire la relation d’adjacence entre les motifs à différents niveaux de résolution, et pour chaque motif, six fonctions d'appartenance floue ont été établies pour attribuer une probabilité d'association avec un tissu normal ou une cible pathologique. Enfin, (4) une étape de décision exploite les classifications par la logique floue afin de sélectionner la classe cible de chaque motif du poumon parmi les catégories suivantes : normal, emphysème, fibrose/rayon de miel, et verre dépoli. La validation expérimentale du système développé a permis de définir des spécifications relatives aux valeurs recommandées pour le nombre de niveaux de résolution NRL = 12, et le protocole d'acquisition comportant le noyau de reconstruction “LUNG” / ”BONPLUS” et des collimations fines (1.25 mm ou moins). Elle souligne aussi la difficulté d'évaluer quantitativement la performance de l'approche proposée en l'absence d'une vérité terrain, notamment une évaluation volumétrique, la sélection large des bords de la pathologie, et la distinction entre la fibrose et les structures (vasculaires) de haute densité / This research aims at developing a computer-aided diagnosis (CAD) system for fully automatic detection and classification of pathological lung parenchyma patterns in idiopathic interstitial pneumonias (IIP) and emphysema using multi-detector computed tomography (MDCT). The proposed CAD system is based on 3-D mathematical morphology, texture and fuzzy logic analysis, and can be divided into four stages: (1) a multi-resolution decomposition scheme based on a 3-D morphological filter was exploited to discriminate the lung region patterns at different analysis scales. (2) An additional spatial lung partitioning based on the lung tissue texture was introduced to reinforce the spatial separation between patterns extracted at the same resolution level in the decomposition pyramid. Then, (3) a hierarchic tree structure was exploited to describe the relationship between patterns at different resolution levels, and for each pattern, six fuzzy membership functions were established for assigning a probability of association with a normal tissue or a pathological target. Finally, (4) a decision step exploiting the fuzzy-logic assignments selects the target class of each lung pattern among the following categories: normal (N), emphysema (EM), fibrosis/honeycombing (FHC), and ground glass (GDG). The experimental validation of the developed CAD system allowed defining some specifications related with the recommendation values for the number of the resolution levels NRL = 12, and the CT acquisition protocol including the “LUNG” / ”BONPLUS” reconstruction kernel and thin collimations (1.25 mm or less). It also stresses out the difficulty to quantitatively assess the performance of the proposed approach in the absence of a ground truth, such as a volumetric assessment, large margin selection, and distinguishability between fibrosis and high-density (vascular) regions

Les pathologies infiltrantes diffuses recensent un large groupe de désordres pulmonaires et nécessitent un suivi régulier en imagerie tomodensitométrique (TDM). Une évaluation quantitative est nécessaire pour établir la progression (régionale) de la maladie et/ou l’impact thérapeutique. Cela implique le développement d’outils automatiques de diagnostic assisté par ordinateur (DAO) pour la segmentation du tissu pathologique dans les images TDM, problème adressé comme classification de texture. Traditionnellement, une telle classification repose sur une analyse des caractéristiques texturales 2D dans les images TDM axiales selon des critères définis par l’utilisateur. Récemment, des techniques d’intelligence artificielle fondées sur l’apprentissage profond, notamment les réseaux neuronaux convolutionnels (CNN), ont démontré des performances meilleures pour résoudre des tâches visuelles. Toutefois, pour les architectures CNN « classiques » il a été prouvé que les performances étaient moins bonnes en classification de texture par rapport à la reconnaissance d’objets, en raison de la dimensionnalité intrinsèque élevée des données texturales. Dans ce contexte, ce travail propose un système automatique pour l’analyse quantitative des pathologies infiltrantes diffuses du poumon fondé sur une architecture CNN en cascade (conçue spécialement pour l’analyse de texture) et sur un prétraitement spécifique des données d’entrée par filtrage localement connexe (permettant d’atténuer l’intensité des vaisseaux pulmonaires et d’augmenter ainsi le contraste des régions pathologiques). La classification, s’appliquant à l’ensemble du volume pulmonaire, atteint une précision moyenne de 84% (75.8% pour le tissu normal, 90% pour l’emphysème et la fibrose, 81.5% pour le verre dépoli) / Infiltrative lung diseases (ILDs) enclose a large group of irreversible lung disorders which require regular follow-up with computed tomography (CT) imaging. A quantitative assessment is mandatory to establish the (regional) disease progression and/or the therapeutic impact. This implies the development of automated computer-aided diagnosis (CAD) tools for pathological lung tissue segmentation, problem addressed as pixel-based texture classification. Traditionally, such classification relies on a two-dimensional analysis of axial CT images by means of handcrafted features. Recently, the use of deep learning techniques, especially Convolutional Neural Networks (CNNs) for visual tasks, has shown great improvements with respect to handcrafted heuristics-based methods. However, it has been demonstrated the limitations of "classic" CNN architectures when applied to texture-based datasets, due to their inherently higher dimension compared to handwritten digits or other object recognition datasets, implying the need of redesigning the network or enriching the system to learn meaningful textural features from input data. This work addresses an automated quantitative assessment of different disorders based on lung texture classification. The proposed approach exploits a cascade of CNNs (specially redesigned for texture categorization) for a hierarchical classification and a specific preprocessing of input data based on locally connected filtering (applied to the lung images to attenuate the vessel densities while preserving high opacities related to pathologies). The classification targeting the whole lung parenchyma achieves an average of 84% accuracy (75.8% for normal, 90% for emphysema and fibrosis, 81.5% for ground glass)

No description available.

Chronic obstructive pulmonary disease (COPD) describes a range of lung conditions including emphysema, chronic bronchitis and small airways disease. While COPD is a major cause of death and debilitating illness, current clinical assessment methods are inadequate: they are a poor predictor of patient outcome and insensitive to mild disease. A new imaging technology, hyperpolarised xenon MRI, offers the hope of improved diagnostic techniques, based on regional measurements using functional imaging. There is a need for quantitative analysis techniques to assist in the interpretation of these images. The aim of this work is to develop these techniques as part of a clinical trial into hyperpolarised xenon MRI. In this thesis we develop a fully automated pipeline for deriving regional measurements of lung function, making use of the multiple imaging modalities available from the trial. The core of our pipeline is a novel method for automatically segmenting the pulmonary lobes from CT data. This method combines a Hessian-based filter for detecting pulmonary fissures with anatomical cues from segmented lungs, airways and pulmonary vessels. The pipeline also includes methods for segmenting the lungs from CT and MRI data, and the airways from CT data. We apply this lobar map to the xenon MRI data using a multi-modal image registration technique based on automatically segmented lung boundaries, using proton MRI as an intermediate stage. We demonstrate our pipeline by deriving lobar measurements of ventilated volumes and diffusion from hyperpolarised xenon MRI data. In future work, we will use the trial data to further validate the pipeline and investigate the potential of xenon MRI in the clinical assessment of COPD. We also demonstrate how our work can be extended to build personalised computational models of the lung, which can be used to gain insights into the mechanisms of lung disease.

La Enfermedad Pulmonar Obstructiva Crónica (EPOC), presenta signos y síntomas sistémicos que se han venido explorando desde hace algún tiempo. La presente Tesis Doctoral estudia la disfunción que presentan los músculos respiratorios y periféricos, específicamente el cuádriceps de los pacientes con EPOC. Esta disfunción muscular afecta las actividades de la vida diaria, la tolerancia al ejercicio, limita la calidad de vida y disminuye la expectativa de vida de estos pacientes. Una de las posibles causas de disfunción muscular en los pacientes con EPOC puede ser la pérdida de masa muscular; por eso nos dedicamos a evaluar, los datos antropométricos de los pacientes con EPOC que asistieron durante 2 años a nuestro Laboratorio de Función Respiratoria del Hospital del Mar de Barcelona. La prevalencia de bajo peso en pacientes con EPOC en un hospital con predominante población mediterránea con, índice de masa corporal (IMC) por debajo de 20 Kg/m2, fue de tan sólo 6,6%, cifra que se reducía al 3,1% si el dintel escogido era de 18 Kg/m2. Estas cifras van claramente en oposición a la prevalencia referida en el mundo anglosajón y del norte-centro europeo, que muestra una prevalencia de bajo peso en pacientes con EPOC que oscila entre el 25 y el 35%. Teniendo en cuentas estos datos de baja prevalencia de bajo peso en nuestros pacientes con EPOC, no se explica la alta prevalencia de disfunción muscular en ellos. Por ello evaluamos variables de función muscular en pacientes con EPOC grave, específicamente del músculo cuádriceps y encontramos que los pacientes con EPOC tenían una disminución tanto de la fuerza muscular (43%), como de la resistencia muscular (77%), al compararlos con controles del mismo grupo etáreo.Tratando de profundizar en la causa de la disfunción muscular periférica en los pacientes con EPOC, hicimos a continuación otro estudio donde evaluamos el daño sarcoplásmico y sarcomérico mediante inmunohistoquímica y microscopía electrónica. Este trabajo demostró por primera vez que los pacientes con EPOC presentan mayor daño a nivel del músculo cuádriceps que los controles sanos.Debido a que en la EPOC los músculos periféricos, específicamente los de las extremidades inferiores, pudieran estar afectados por el sedentarismo, decidimos estudiar otras causas de disfunción muscular en un grupo de músculos en que este factor se hallara ausente, como son los músculos respiratorios. Estos mantienen su nivel de actividad normal o incluso aumentada. Para ello tomamos un músculo como el intercostal externo, que es fácilmente accesible a la biopsia, siguiendo un modelo mínimamente invasivo descrito por nuestro grupo. Como en trabajos precedentes ya habíamos valorado el daño sarcomérico, el estrés oxidativo o la actividad enzimática, en esta ocasión el trabajo se centró en la evaluación de la actividad inflamatoria. En él se ha demostrado que las citocinas proinflamatorias TNF-α e IL-6 se encuentran aumentadas en los músculos intercostales externos de los pacientes con EPOC al compararlo con los controles sanos. / Chronic Obstructive Pulmonary Disease (COPD), shows systemic sign and symptoms that have been studied for some time. The present Doctoral Thesis studies the dysfunction shown by the respiratory and peripheral muscles, specifically the quadriceps muscle of patients with COPD. This muscle dysfunction affects the activities of daily living, tolerance to exercise, limits quality of life and diminishes life expectancy of these patients. One of the possible causes of muscle dysfunction in the patients with COPD could be the loss of muscle mass; for that reason we evaluated, the anthropometrics data of the patients with COPD that attended during 2 years our Respiratory Function Laboratory, Hospital del Mar of Barcelona. The prevalence of low weight in patients with COPD in a hospital with a predominantly Mediterranean population with an Body Mass Index (BMI) below 20 Kg/m2, was only 6.6%, a figure that was reduced to 3.1% if the chosen threshold was 18 Kg/m2. These numbers starkly contrast to the prevalence in Northern Europe, with a low weight in patients with COPD raging from 25 to 35%. Considering these data of low prevalence of low weight in our patients with COPD, the high prevalence of muscle dysfunction is not explained. We evaluated variables of muscle function in patients with severe COPD, specifically the quadriceps muscle and we found that the patients with COPD had a decreased muscle strength (43%), and muscle endurance (77%), when comparing with healthy age matched. To study the cause of the peripheral muscle dysfunction in patients with COPD, we began another study where we assessed sarcoplasmic and sarcomeric damage by immunohystochemical methods and electronic microscopy. This work demonstrated for the first time that patients with COPD show greater muscle injury at the quadriceps muscle level that healthy age matched controls.Because in COPD, peripheral muscles, specifically those of the lower limbs, could be affected by sedentarism, we decided to study other causes of muscle dysfunction in a muscle group in which this factor was absent, as they are the respiratory muscles. These maintain their level of normal activity or activity is even increased. For this we chose a respiratory muscle like the external intercostal muscle, that is easily accessible by biopsy, following a minumum invasive model described by our group. As in preceding works of our group we evaluated the sarcomeric damage, oxidative stress or the enzymatic activity, the present work was focused in the inflammatory activity evaluation. We demonstrated that proinflammatory cytokines such as TNF-α and IL-6 are increased in the external intercostal muscles of patients with COPD when comparing with healthy age matched controls.