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Introduction The nitrofen model of congenital diaphragmatic hernia (CDH) creates a Bochdalek-type diaphragmatic defect and has been widely used to investigate the pathogenesis of CDH. However, the exact pathogenesis of the diaphragmatic defect in this model is still poorly understood. Chicken ovalbumin upstream promotor-transcription factor II (COUP-TFII) is expressed in the embryonic pleuroperitoneal folds (PPF) in the early stage of development and in the diaphragm in the late days of gestation. COUP-TFII is known to be a strong repressor of the retinoid signaling pathway (RSP), which plays an important role in diaphragm development. Furthermore, it has been recently shown that COUP-TFII is upregulated during early gestation in the nitrofen-induced hypoplastic lung. We designed this study to investigate the hypothesis that COUP-TFII gene expression is upregulated during early diaphragmatic development in the PPF.Material and Methods Timed pregnant rats were exposed to either olive oil (Control) or nitrofen (CDH) on day 9 of gestation (D9). Fetuses were sacrificed on D13, D18 or D21. The PPF was dissected from D13 fetuses using laser capture microdissection. Diaphragms were dissected from D18 and D21 fetuses under the dissection microscope. The relative mRNA expression levels of COUP-TFII were determined using real-time PCR. Immunohistochemistry was performed to evaluate diaphragmatic protein expression and the distribution of COUP-TFII.Results On D13, gene expression levels of COUP-TFII in the PPF were significantly increased in the CDH group (82.93 ± 11.85) compared to Controls (46.22 ± 8.09; p < 0.05), whereas there were no differences at later time points. The immunoreactivity of diaphragmatic COUP-TFII was markedly increased in the PPF in the CDH group compared to Controls on D13. No difference in immunoreactivity was observed on D18 and D21.Conclusion Upregulation of COUP-II gene expression in the PPF may contribute to the diaphragmatic defect in the nitrofen CDH model by inhibiting the RSP. [ABSTRACT FROM AUTHOR]

Purpose: The precise mechanism of pulmonary hypoplasia (HP) associated with congenital diaphragmatic hernia (CDH) remains unclear. Insulin- like growth factors (IGFs) play an essential role in fetal lung development through IGF receptors (IGFRs) by regulating cellular proliferation, differentiation and survival. It has been reported that the expression of genes involved in IGF-IGFR signaling is altered in the nitrofen-induced hypoplastic lung during the later stages of lung development. IGF-binding proteins (IGFBPs) control bioavailability, activity and disruption of IGFs through the high affinity IGFBP/IGF complexes. IGFBP-4 is a key inhibitor of IGF-IGFR signalingmediated cell proliferation. It has been revealed that cell proliferation in fetal lung fibroblasts is inhibited by increased IGFBP-4 production. We hypothesized that IGFBP-4 gene expression is increased during the later stages of lung development in the nitrofen-induced CDH lung. Methods: Pregnant Sprague-Dawley rats were exposed to either olive oil or nitrofen on day 9 (D9) of gestation. Fetuses were harvested by cesarean section on D18 and D21. Fetal lungs were divided into 3 groups: control, nitrofen without CDH [CDH(-)] and nitrofen with CDH [CDH( + )] (n = 24 at each time point). Relative mRNA levels of IGFBP-4 were determined using real-time RT-PCR. Immunohistochemistry was performed to evaluate the protein expression of IGFBP-4. Results: The relative expression levels of IGFBP- 4 mRNA were significantly increased in CDH(-) and CDH(+) groups on D18 and D21 compared to controls. Immunohistochemistry showed increased IGFBP-4 expression in mesenchymal compartments on D18 and D21 in hypoplastic lungs compared to controls. Conclusion: Overexpression of pulmonary IGFBP-4 during the later stages of lung development may contribute to pulmonary hypoplasia in the nitrofen-induced CDH model by inhibiting IGF-mediated cell proliferation. [ABSTRACT FROM AUTHOR]

Introduction: The nitrofen model of Congenital Diaphragmatic Hernia (CDH) displays a diaphragmatic defect of the Bochdalek-type and has been widely used to investigate the pathogenesis of CDH. However, the exact pathomechanism of the diaphragmatic defect is still poorly understood. Fibroblast growth factor (FGF) receptorlike 1 (FGFRL1), a member of the FGF receptor family, plays a key role in physiological diaphragmatic development. FGFRL1 is expressed in the fetal diaphragm at low levels in early gestation and its expression steadily increases, becoming most pronounced in later gestational stages. It has been reported that FGFRL1 homozygous null mice have thin, partially amuscular diaphragms and die at birth due to respiratory failure. The aim of this study was to investigate the hypothesis that FGFRL1 gene expression in the diaphragm is downregulated during the later gestational stages in the nitrofen CDH model. Material and Methods: Timed pregnant rats were exposed to either olive oil or 100 mg nitrofen on day 9 of gestation (D9). Cesarean section was performed on D18 or D21. Fetal diaphragms (n = 40) were micro-dissected and divided into CDH group and controls. Total RNA was extracted from the diaphragms and the mRNA levels of FGFRL1 were determined using real-time PCR. Immunohistochemistry was performed to evaluate diaphragmatic protein expression of FGFRL1. Student ' s t-test and Mann-Whitney test were used, where appropriate. Statistical significance was considered for p < 0.05. Results: Relative mRNA expression levels of FGFRL1 were significantly decreased in the CDH group compared to controls on D18 (3.63±1.65 vs. 6.04±3.12, p <0.05) and D21 (1.36±1.01 vs. 2.57±1.34, p <0.05). Immunoreactivity of FGFRL1 was markedly decreased in the diaphragms of the CDH group compared to controls on D18 and D21. Conclusion: Our data provide strong evidence that downregulation of the FGFRL1 gene during the late stages of gestation may contribute to the development of the diaphragmatic defect in nitrofen-induced CDH. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary hypoplasia is a primary cause of high morbidity and mortality in neonates with Congenital Diaphragmatic Hernia (CDH). However, the precise pathogenesis of PH associated with CDH is still not clearly understood. It has been recently reported that lung Kruppel-like factor (LKLF), a member of the Kruppel-like factor family of transcription factors, is predominantly expressed in lungs and plays an important role in lung morphogenesis and functional maturation. It has been reported that homozygous deletion of LKLF gene in mice results in reduced lung morphogenesis. It is further reported that chimeric mice derived from LKLF-/- embryonic stem cells exhibit delayed lung development especially in the later gestational stages. We therefore designed this study to test the hypothesis that the LKLF gene is down-regulated during later stages of lung development in nitrofen-induced hypoplastic lungs. Material and Methods: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetal lungs were harvested on D15, D18, and D21 and divided into 3 groups:control, nitrofen without CDH(CDH( - )) and nitrofen with CDH(CDH(+)) (n = 24 for each group). Realtime RT-PCR analysis was performed to investigate pulmonary gene expression levels of LKLF. Differences between the 3 groups at each time point were tested statistically and significance was accepted at p < 0.05. Immunohistochemistry was also performed to evaluate LKLF protein expression and distribution. Results: The relative mRNA expression levels of LKLF on D18 and D21 were significantly decreased (p < 0.01) in CDH( - ) and CDH( + ) groups compared to controls. The gene expression levels of LKLF on D15 did not differ significantly between the nitrofen group and controls. Immunohistochemical study showed strong LKLF immunoreactivity on D18 and D21 in nitrofeninduced hypoplastic lung compared to controls, whereas no difference was seen on D15. Conclusions: Our results provide evidence for the first time that LKLF is down-regulated in the later stages of lung development in nitrofen- induced hypoplastic lungs. These data suggest that the down-regulation of LKLF during this critical period of lung morphogenesis may impair lung development and maturation, resulting in pulmonary hypoplasia in the nitrofen CDH model. [ABSTRACT FROM AUTHOR]

Background: Ovarian tumors are rare in the pediatric age group and thus diagnostic and treatment strategies are heterogeneous. This study aims to evaluate ovarian tumors with a focus on age at presentation, imaging characteristics, diagnostic strategy, tumor presentation and management., Methods: Data was collected retrospectively from patients admitted between 1991 and 2008 for the evaluation and therapy of ovarian tumors., Results: Twenty-five patients were identified with neoplastic ovarian lesions (mean age 10.7 years). Sixteen patients (64%) underwent surgery for benign and 9 (36%) for malignant tumors. Benign tumors (n=16) had a mean diameter of 10.7 cm and mean age at presentation was 9.6 years compared to a diameter of 18.6 cm and 12.3 years in the malignant group (n=9). Elevated tumor markers were observed in 3 (12.5%) benign tumors and in 7 (77.8%) malignant tumors. In preoperative ultrasound investigation, cyst formation was identified in 4 benign tumors and solid tumor mass in 2 malignant tumors. A minimally invasive surgical approach was chosen in two patients, while open surgery was opted for in the rest., Conclusion: Cyst formation, small tumor size and younger age at presentation were characteristic of benign tumors. Malignant tumors often presented with elevated tumor markers, a larger size and a solid consistency. Diagnostic dilemmas remain for both tumor groups due to the different tumor types and the heterogeneity of presentation.