Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Congenital abnormalities of the diaphragm, specifically congenital diaphragmatic hernia (CDH), affect 1 in 3,000 live births and are associated with substantial morbidity and mortality. Evidence in humans and animal models support genetic causation. The etiology of most cases, however, remains unknown, though is likely polygenic in the majority. Another impediment to uncovering CDH etiology is that collection of human specimens at the onset of diaphragm development (4 weeks gestation) is not feasible. Identification of key transcriptional programs involved in normal diaphragm development is needed to gain a more comprehensive understanding of the genetic etiology of CDH. As an initial step, unique transcriptome-wide data sets are generated from laser-captured mouse embryonic diaphragms at three key time-points of diaphragm development. These data sets provide the first unbiased perspective on genes and signaling pathways active during early and late diaphragm morphogenesis. Moreover, using a curated list of known CDR-associated genes as "baits", the normal expression data sets are filtered for identification of biologically relevant CDH candidate genes. By this approach, 27 novel CDH candidate genes are described, among which, pre-B cell leukemia transcription factor 1 (Pbxl) is selected to validate the prioritization approach. Diaphragm defects resembling the human CDH phenotype, never previously appreciated, are observed among Pbxl mutant mice at E15.5. Secondly, a human family containing several affected individuals with CDH is used for gene discovery. A multiplatform analysis approach, coupled with external filtering with the normal diaphragm expression data, provide a mechanism for identification of candidate modifier loci. This integrative strategy, which identifies a FOG2 deletion and several potential modifiers of the CDH phenotype, is described. The design of a customized diagnostic/discovery capture array for next-generation sequencing of a large CDH patient cohort uses the set of CDR-candidate genes identified herein. / 2031-01-02

Traumatic diaphragmatic hernia (TDH) is a known complication in patients with abdominal injuries. Delayed TDH, which presents long after the traumatic event, is a rare subset and is often missed upon initial presentation. We discuss a case involving a 15-year-old female who presented with persistent nausea, vomiting, and epigastric pain and was subsequently diagnosed with TDH via chest x-ray, later confirmed by CT scan. Further investigation of the patient's history revealed a motor vehicle accident one year prior in which the patient sustained an injury to the left chest. A chest x-ray at that time did not show signs of a diaphragmatic hernia. Surgical evaluation of the diaphragmatic defect further supported previous trauma as the mechanism of injury. Our patient's presentation is particularly interesting considering the lack of TDH reported in the pediatric population, as well as the presenting complaints being primarily gastrointestinal rather than respiratory.

Thesis (doctoral)--Faculté de médecine de Paris, 1866. / At head of title: Faculté de médecine de Paris.

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.

Pulmonary vascular disease (PVD) and lung hypoplasia (LH) are the two main causes of mortality and morbidity in patients with congenital diaphragmatic hernia (CDH). Previous studies have shown that remodeling of the extracellular matrix (ECM) by elastase and matrix metalloproteinase (MMP) enzymes, concomitant with smooth muscle cell (SMC) proliferation and deposition of ECM proteins and growth factors, leads to primary pulmonary hypertension (PH) and that blockade of this pathway results in disease reversal. The aim of our study is to determine whether a similar pathway is induced in the PVD associated with CDH and to verify whether its inhibition will lead to reversal of PVD. Firstly, we confirmed various aspects of PVD in the nitrofen induced CDH rat model. These included: left lung hypoplasia, right ventricular hypertrophy, and increased arterial smooth muscle wall thickness alongside decreases in arterial lumen area and total number of distal pulmonary vessels. We also showed increases in elastase and matrix metalloproteinase (MMP) enzyme activities within distal pulmonary arteries (PAs), which, we were able to inhibit using serine elastase (sivelestat, elafin, and serpina1) and MMP (GM6001) inhibitors. Furthermore, we confirmed increased SMC proliferation and deposition of osteopontin (OPN) and epidermal growth factor (EGF) within the diseased vasculatures. We are now working on using sivelestat and GM6001 pharmaceuticals as well as endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) modified to express elafin and serpina1 to determine their abilities to reverse the PVD associated with CDH. This project is part of our translational research program with the ultimate goal of developing a novel strategy of targeting PVD in infants with CDH to improve patient survival and long-term outcome.

No description available.

A hérnia diafragmática congênita (CDH) tem incidência de aproximadamente 1:2500 nascidos vivos e mortalidade de aproximadamente 70%. A hipertensão arteiral pulmonar é umas das principais complicações neonatais e pode levar à sobrecarga cardíaca. A principal estratégia de tratamento para os casos de grave hipoplasia pulmonar no período pré-natal é a traqueo-oclusão fetal (TO), no entanto, as consequências geradas ao tecido cardíaco são incertas, tanto na CDH quanto no tratamento com TO. Troponininas (cTnI e cTnT) são proteínas intracelulares miocárdicas utilizadas como indicativo de lesão cardiomiocítica. Portanto, nosso objetivo foi avaliar as alterações anatômicas, funcionais e bioquímicas dos ventrículos esquerdo (VE) e direito (VD) na CDH e CDHTO por meio das análises de ecocardiografia (ECO), histologia e bioquímica no modelo experimental de CDH. Para isso, foram utilizados neonatos de coelhos (n=10) divididos em três grupos: controle (C), hérnia diafragmática congênita (CDH), e hérnia diafragmática congênita + traqueo-oclusão (CDHTO). A cirurgia de CDH foi realizada no dia 25 da gestação (DG) da coelha (termo = 31 dias), e a TO no 27DG. A coleta foi realizada em 30DG, a ECO neonatal foi realizada imediatamente após retirada do útero e após o sacrifício os pulmões e coração foram coletados. A mortalidade da CDH fi de 20% e de CDHTO de 30%. Os resultados da ECO e da histologia mostraram hipoplasia de VE nos grupos CDH e CDHTO (*p<0,05), sendo que no VD, o grupo CDH apresentou dilatação e o grupo CDHTO apresentou hipoplasia. Na imunofluorescência (IF), western blotting (WB) e RT-qPCR houve aumento de cTnI no VD dos grupos CDH e CDHTO em relação à C (*p<0,05), sem alteração de expressão de cTnI no VE (NS); cTnT não apresentou alteração em ambos ventrículos (NS). Concluímos que as alterações cardíacas em CDH e CDHTO podem ser verificadas logo após o nascimento e há associação das alterações ecocardiográficas, histométricas e bioquímicas, como a hipoplasia de VE e dilatação de VD associada ao aumento tecidual de cTnI no VD no grupo CDH, indicando sofrimento cardíaco ainda no período fetal. Além disso, a realização do tratamento fetal pela TO no grupo CDH (CDHTO) não apresentou melhora das alterações do comprometimento do miocárdio. / Congenital diaphragmatic hernia (CDH) has an incidence of approximately 1: 2500 live births and a mortality rate of approximately 70%. Pulmonary hypertension is one of the major neonatal complications and can lead to cardiac overload. The main treatment strategy for cases of severe prenatal pulmonary hypoplasia is fetal tracheal occlusion (TO), however, the consequences in the cardiac tissue are uncertain, in both the CDH and the TO treatment. cTnI and cTnT are myocardial intracellular proteins used as an indicative of cardiomyocyte injury that could be measured in neonates with CDH. Therefore, our aim was to evaluate the anatomical, functional and biochemical alterations in the left ventricle (LV) and in the right ventricle (RV) of neonates with CDH and CDHTO through echocardiography (ECO), histology and biochemistry analysis in the experimental rabbit CDH model. Neonates of rabbits (n = 10) were divided into three groups: C (control), CDH (congenital diaphragmatic hernia) and CDHTO (congenital diaphragmatic hernia + tracheal occlusion). CDH surgery was performed on day 25 of gestation (GD) of the rabbit (term = 31 days), and TO treatment on 27GD. The harvest was performed in 30GD, followed by neonatal ECO immediately after birth, then after sacrifice the lungs and heart were harvested. The mortality in the surgical groups was 20% CDH and 30% CDHTO. The ECO and histology results showed LV hypoplasia in the CDH and CDHTO (* p <0.05) groups. In the RV, the CDH group presented dilation and the CDHTO group presented hypoplasia. In the immunofluorescence (IF), western blotting (WB) and RTqPCR analysis there was an increase of cTnI in the RV of CDH and CDHTO groups in comparison with C group (* p<0.05), with no alteration of cTnI expression in the LV (NS). There was no difference of cTnT expression in both ventricles (NS). We conclude that cardiac alterations in CDH and CDHTO can be verified soon after birth, also there is an association of echocardiographic, histometric and biochemical alterations, such as LV hypoplasia and RV dilation with increased cTnI tissue expression in the RV of CDH group, indicating cardiac distress still in the fetal period. In addition, the performance of CDH fetal treatment by TO, (CDHTO) group, did not improve the myocardial detriment.

The birth of a child diagnosed with congenital diaphragmatic hernia (CDH) involves significant intensive care at the beginning of life and the need for surgery. Parents’ experiences during the acute phase of hospitalization for a critically ill infant not born premature is currently limited in the literature; in particular, there is no literature describing parents’ experiences of nursing care for having a infant with CDH in the Neonatal Intensive Care Unit (NICU). Using narrative inquiry this study explores stories of parents’ early experiences of nursing care in the NICU for an infant born with CDH. A thematic analysis revealed a main overarching theme of “not knowing” with three interrelated subthemes related to parents’ need for information and open communication; participation, power and partnership; and nursing presence to transition from not knowing to knowing their infant. The findings from this study suggest that parents want to be recognized as key members within the multidisciplinary team and that the nurse has the ability to facilitate aspects of care to impact parents positively or negatively. Implications for practice focus on supporting parents through evolving empowerment and participation in the care of their infant. / Graduate / 0569

INTRODUCTION: Pulmonary hypoplasia causes high morbidity and mortality in congenital diaphragmatic hernia (CDH) patients. MiR-10a and miR-200b are overexpressed in human CDH lungs. We aimed to define their roles in lung development. METHODS: We profiled miR-10a expression with RT-qPCR and in situ hybridization using a nitrofen rat model for CDH. The effects of miR-10a on airway branching were evaluated in lung explants. MiR-200b’s role in airway branching was assessed in miR-200b knockout lung explants. Crossing miR-200b knockout mice with CFP-E-Cadherin was used to evaluate miR-200b’s effects on epithelial differentiation. RESULTS: Expression of miR-10a was altered in the nitrofen model and miR-10a mimics reversed lung hypoplasia in vitro. Heterozygous miR-200b lung explants displayed reduced airway branching. CFP-E-Cadherin/miR-200b knockout lung explants showed reduced epithelial expression. CONCLUSION: Both miR-10a and miR-200b are critical for lung development and CDH. Normalizing their expression may reverse lung hypoplasia and reduce the associated morbidity and mortality in CDH. / February 2016

Les prothèses diaphragmatiques en ePTFE utilisées dans la hernie diaphragmatique congénitale à large défect ont une faible étirabilité, ce qui entrainera des récidives herniaires au cours de la croissance de l’enfant. En effet, l’analyse en imagerie montre que la surface du diaphragme grandit de 4-5 fois jusqu’à l’adolescence. De plus, les mesures de rigidité des surfaces de prothèses explantés, montrent l’influence des contraintes mécaniques appliquées sur la structure des matrices extracellulaires néoformées. Afin de favoriser l’intégration tissulaire du ePTFE, nous avons testé un moyen de fonctionnaliser le ePTFE avec la polydopamine sur une seule face. Le revêtement nanoscopique favorise la colonisation cellulaire. Enfin, ce travail de thèse présente une méthode originale de réalisation d’une nouvelle membrane bicouche avec des propriétés mécaniques conformes aux exigences chirurgicales. Ce biomatériau innovant et prometteur fait actuellement l’objet d’une Déclaration d’invention. / Electron microscopy assessments of ePTFE prosthesis explants for diaphragmatic congenital hernia repair strongly suggest that the tissue responses are directly related to the surface microstructure of the biomaterial. AFM measurements (Young moduli) emphasize the influence of the mechanical stress applied to the implant on the mechanical properties of the newly formed extracellular matrices. In order to guide the host responses, we undertook to functionalize with polydopamine the ePTFE biomaterial. Electron microscopy investigations reveal the interest of that surface treatment regarding cell colonization of implant. To optimize that approach, we developed an original method aimed to coat only one face of the biomaterial. After determination of the growth rate of the diaphragm from birth to adolescence, we explored the possibility to design a new double-faced mesh able to follow body growth. From this point of view, the initial prototypes are promising and under patent application.