Bei kongenitalen Zwerchfelldefekten kommt es zu einer Herniation von abdominellen Organen in den Thorax. Es resultieren eine Lungenhypoplasie und eine pulmonale Hypertonie, die die hohe Mortalität und Morbidität bestimmen. In dieser Studie wurden prä-, peri- und postnatale Parameter von Patienten mit kongenitalen Zwerchfelldefekten retrospektiv betrachtet und auf eine mögliche Prädiktion für das Outcome sowie auf therapeutische Qualitätsänderungen überprüft. Im prospektiven Teil wurde die weitere Entwicklung der Kinder nach dem stationären Aufenthalt eruiert. Statistisch signifikante Unterschiede zeigten sich für einen höheren 1’ APGAR, eine seltenere Anwendung von NO und ein selteneres Vorkommen von assoziierten Anomalien bei den überlebenden verglichen mit den verstorbenen Patienten. Die Überlebenden hatten niedrigere Beatmungsfrequenzen, inspiratorische Spitzendrücke, Sauerstoffkonzentration sowie Mitteldrücke bei Beatmung und höhere arterieller Mitteldrücke. Als negativ für das Outcome erwiesen sich ein Polyhydramnion, eine Leberherniation oder die Notwendigkeit einer HFOV. Im zeitlichen Verlauf zeigten sich ein höherer 5’ APGAR, eine zeitigere Diagnosestellung in der Schwangerschaft, eine spätere Durchführung der Operationen und seltenere Rezidive. Die Kinder wurden mit niedrigeren Beatmungsdrücken und niedrigerem Sauerstoffgehalt beatmet, ohne dass sich das Outcome verschlechterte. Bezüglich der späteren Entwicklung gab es orthopädische und neurologische Folgen. Die Kinder hatten nur wenige Einschränkungen im Alltag. Dennoch zeigte sich das potentielle Auftreten einer Minderung der kognitiven Fähigkeiten.

No description available.

No description available.

Largely as a consequence of the ongoing obesity epidemic, research into adipose tissue biology has increased substantially in recent years. Worldwide, the number of people classed as overweight or obese is growing, and this represents a major public health concern. Adipose tissue is broadly divided into two types; white and brown. Whilst white adipose tissue (WAT) functions to store and mobilise triglycerides, brown adipose tissue burns chemical energy to generate heat. WAT is further divided into visceral “bad” fat and subcutaneous “good” fat depots, and it is an increase in the former that is linked to obesity-associated diseases. As well as adipocytes, several other cell types including haematopoietic and endothelial are found within adipose tissue, and comprise the stromal vascular fraction (SVF). Adipocyte precursor cells (APCs) also reside within the SVF and are essential for the maintenance and expansion of adipose tissue. The protein encoded by the Wilms’ tumour 1 (Wt1) gene is predominantly known to function as a transcription factor, but also has a role in post-transcriptional processing. Deletion of Wt1 in adult mice results in a considerable loss of fat tissue. Moreover, recent work has revealed that a proportion of the APCs from all visceral WAT depots express Wt1, therefore revealing heterogeneity within the APC population. Additionally, visceral WAT depots are encapsulated by a WT1 expressing mesothelial layer, which has its origins in the lateral plate mesoderm (LPM), and can give rise to mature adipocytes. Lineage tracing has demonstrated that a significant proportion of the mature adipocytes in all adult visceral WAT depots (but not subcutaneous) are derived from cells that express Wt1 in late gestation. These findings uncovered key ontogenetic differences between visceral and subcutaneous WAT and led us to ask whether Wt1 functions in visceral adipose tissue biology. Preliminary work has shown that adipocytes derived from Wt1 expressing (Wt1+) precursor cells have fewer, larger lipid droplets than those derived from non-Wt1 expressing (Wt1-) precursors. In this thesis, this heterogeneity is explored further using a Wt1GFP/+ knock-in mouse. When Wt1+ and Wt1- APCs are cultured separately, the Wt1+ population differentiate into adipocytes more readily. Moreover, the Wt1+ APCs are more proliferative than the Wt1-. Preliminary results also suggest that the Wt1+ APCs may secrete a factor(s) that causes the Wt1- APCs to exhibit improved adipogenic differentiation, a result that is supported by data from comparative transcriptomic analysis. Finally, the percentage of APCs decreases when mice are fed a high fat diet. Interestingly, this decrease is more pronounced for the Wt1+ population. Therefore, it appears that as well as exhibiting differing behaviours in vitro, the Wt1+ and Wt1- populations respond differently to physiologically relevant conditions in vivo. Whilst the LPM is a major source of visceral WAT, the origin of subcutaneous WAT is currently unknown. Here, the Prx1-Cre and Prx1-CreERT2 mouse lines are used to investigate this. It is shown that the majority of subcutaneous WAT adipocytes and APCs are labelled by Prx1-Cre, however this is not the case for most of the visceral WAT depots. The exception to this is the pericardial (heart fat) depot, in which approximately 70% of the adipocytes and 40% of the APCs are labelled. Moreover, a proportion of the Prx1-Cre labelled pericardial APCs also express Wt1, therefore suggesting additional heterogeneity. Preliminary results show that this heterogeneity may have functional consequences, at least in vitro. Additionally, lineage tracing studies suggest that the somatic LPM may be one source of subcutaneous WAT and pericardial visceral WAT Finally, it is shown that the conditional deletion of Wt1 in the Prx1-Cre lineage results in abnormal diaphragm development. Congenital diaphragmatic hernia (CDH) is severe birth defect, the etiology of which is not well understood. Here, a new model of CDH has been developed, and the cellular and molecular mechanisms responsible for the defect in this model are investigated.

Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

Die vorliegende Arbeit beschäftigt sich mit der Anwendung der sonographischen Lungenbiometrie in der Pränataldiagnostik zur Erkennung einer Lungenhypoplasie. Im ersten Abschnitt wurden anhand definierter Messebenen Normwerte für verschiedene biometrische Parameter (Durchmesser, Länge) der fetalen Lunge erstellt. Im zweiten Abschnitt wurde diese Meßmethode mit Hilfe eines Hochrisikokollektivs (N=29) für die intrauterine Entwicklung einer Lungenhypoplasie hinsichtlich ihrer prognostischen Aussagekraft untersucht. Es konnte nur eine sehr geringe Sensitivität und Spezifität der verschiedenen Messebenen festgestellt werden. Die Vierkammerblickebene wies mit Werten für die Sensitivität von 57% und 44 % sowie für die Spezifität von 42 % und 50 % noch die höchste Validität auf. Eine Fehlbildung, die typischerweise mit der Ausbildung einer Lungenhypoplasie einhergeht, ist die kongenitale Zwerchfellhernie. Da die beschriebenen Messebenen bei dieser Fehlbildung nur schwer zu verwenden sind, wurde in der Literatur ein neuer Parameter, die Lung-to-Head-Ratio, in die pränatale Diagnostik eingeführt. In einem dritten Abschnitt wurde die Lung-to-Head-Ratio (LHR) prospektiv in ihrer prognostischen Aussagekraft bei 18 Feten mit isolierter Zwerchfellhernie untersucht. Neben dem Outcome (Überleben) wurden auch neonatale Ventilationsparameter sowie das Risiko der Entwicklung einer pulmonalen Hypertonie untersucht. Für die LHR konnte kein signifikanter Einfluß auf das Outcome gefunden werden. Es konnte kein signifikanter Zusammenhang zwischen der pränatal bestimmten Lungengröße und dem postnatalen Verlauf der Beatmungsparameter bzw. dem Risiko der Entwicklung einer pulmonalen Hypertonie gefunden werden. Die sonographische Erkennung einer Lungenhypoplasie ist möglich. Mit den derzeit vorhandenen Messebenen ist jedoch eine Einschätzung der Prognose einer Lungenhypoplasie pränatal nicht möglich. Die Ergebnisse unterstützen die Überlegungen, dass die kongenitale Zwerchfellhernie ein sehr komplexes Krankheitsbild ist, welches in seinem Schweregrad nicht nur durch einen Parameter (Lungengröße) eingeschätzt werden kann. / This study analysed the application of the sonographic lung biometry on the prenatal detection of pulmonary hypoplasia. The first chapter defined sonographic levels for the measurement of different biometric parameter (diameter, length) of the fetal lung. The second chapter analysed the application of this method regarding its predictive value in a group with high risk for developing pulmonary hypoplasia (N=29). The sensitivity and specificity of the various measurement levels was low. The level of the four chamber view had the highest validity with a sensitivity of 57 % and 44 % and with a specificity of 42 % and 50 %. The congenital diaphragmatic hernia is a malformation which typically develope pulmonary hypoplasia. The above described measurement levels are difficult to reproduce in congenital diaphragmatic hernia. Therefor a new biometric parameter has been introduced in the literature, the lung-to-Head-Ratio (LHR). In the third chapter the LHR was analysed concerning the evaluation of the prognosis in 18 fetuses with isolated diaphragmatic hernia. The following parameters were examined: outcome of the fetuses; neonatal ventilation parameters; occurance of pulmonary hypertension. There was no significant correlation between the LHR at time of diagnosis of the diaphragmatic hernia and these parameters. The prenatal detection of a pulmonary hypoplasia using the method of sonographic lung biometry is possible. But it is not possible to predict the severity of pulmonary hypoplasia in these cases. It would seem that the lung is a too complex organ for it to be prognostically judged only by measuring a single biometric parameter.

INTRODUCTION. Congenital diaphragmatic hernia (CDH) combines a congenital malformation of the diaphragm with lung hypoplasia, leading to severe respiratory distress and intractable pulmonary hypertension of the newborn. Despite advances in prenatal diagnosis and neonatal intensive care, CDH is associated with high mortality and devastating morbidities. In the absence of curative treatment, numerous prenatal therapies have been used experimentally with varying success. So far, only fetal tracheal occlusion has been tested in clinical trials, but the consequences for the human lung are poorly known. AIMS. To further characterize the rabbit model of CDH, which was subsequently used to assess the effects of prenatal therapies on airway and pulmonary vascular development, including tracheal occlusion, and two novel approaches, perfluorooctylbromide and an activator of soluble guanylate cyclase (BAY 41–2272), which were given through tracheal instillation.METHODS. After a diaphragmatic incision during the pseudoglandular stage, fetal rabbits were randomized against placebo/sham operation during the saccular stage for tracheal occlusion, perfluorocarbon or BAY 41–2272. At term operated fetuses and controls were subject to evaluation of lung mechanics and/or hemodynamics as well as postmortem lung analyses. Human fetal and neonatal lung tissue, including controls and CDH with tracheal occlusion or expectant management, was analyzed histologically and biochemically.RESULTS. The rabbit model of CDH was characterized by reduced lung volumes and impaired compliance, disorders of elastin deposition within alveolar walls, and downregulation of elastogenesis-related genes. Moreover, this model reproduced features of pulmonary hypertension, including high right ventricular pressure and level of N-terminal-pro-B type natriuretic peptide, remodeling of pulmonary arterioles, decreased alveolar capillary density, and downregulation of vasodilation-related genes. In the rabbit model, lung distension caused by tracheal occlusion improved alveolar formation and elastogenesis, yet without correction of lung mechanical parameters. Tracheal occlusion increased also the expression of other extracellular matrix components, which reflected myofibroblast activity, and reduced the transcription of surfactant-associated proteins. Human neonatal lungs exposed to fetal tracheal occlusion displayed alveolar deposits of collagen and myofibroblasts. In human CDH as well as in the rabbit model of CDH, tracheal occlusion enhanced the pulmonary expression of transforming growth factor-β (TGFβ) and Rho kinase−associated proteins to the detriment of activation of SMAD2/3, which is normally detected in human lungs with advancing gestation. As an alternative to tracheal occlusion, pulmonary distension by perfluorocarbon in the fetal rabbit model of CDH improved lung mechanics and alveolar elastogenesis without transcriptional changes in extracellular matrix, surfactant protein genes or TGFβ. Finally, intratracheal instillation of BAY 41–2272 in the rabbit fetuses with CDH improved hemodynamics, reduced medial hypertrophy of pulmonary arterioles, and increased capillary bed formation by stimulating endothelial cell proliferation.CONCLUSIONS. In the fetal rabbit model of CDH, poor lung function after tracheal occlusion is compatible with activation of TGFβ and imbalance in extracellular matrix and epithelial homeostasis. In human CDH newborns treated by fetal tracheal occlusion, changes in the pulmonary interstitium and impaired TGFβ signaling raise the question of disturbances of postnatal lung development induced by tracheal occlusion. As potential alternatives to tracheal occlusion, prenatal perfluorocarbon improves lung hypoplasia, whereas prenatal BAY 41–2272 attenuates pulmonary hypertension. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished

52 8 Summary The influence of defect size and surgical technique on the long-term morbidity of children with congenital diaphragmatic hernia Objective: The aim of this study is to evaluate the effects of diaphragm reconstruction using a synthetic non-absorbable patch from polytetrafluoroethylene (PTFE, Gore-Tex) and primary repair of diaphragm defects on the long-term morbidity in children after surgery of congenital diaphragmatic hernia (CDH), with a primary interest in the influence of these techniques on the occurrence of skeletal deformities and the development of pulmonary functions. One part of this study is to introduce a new objective method for perioperative evaluation of the size of diaphragmatic defects to enable comparison of results among various centres and methods used for diaphragmatic reconstruction. Another part of this study is to evaluate the validity of lung function assessment using four unique methods of Infant Pulmonary Function Tests (IPFT) in children under 13 kg of body weight. Material and Methods: A study of 69 patients operated on between 1996-2010 for CDH, in which the clinical part of the study was performed between the years 2009-2011. The clinical study evaluated anthropometric examination, pulmonary function testing and a questionnaire study which focused on long-term...