History of endoscopic treatment of vesicoureteral reflux.

Since its first clinical application in 1984, the endoscopic subureteral injection of bulking agents has become an alternative to long-term antibiotic prophylaxis and open surgical intervention in the treatment of VUR in children. The 15 min day care endoscopic procedure has gained worldwide popularity in the management of VUR in children. Over the years, multiple studies have demonstrated safety and long-term efficacy of this minimally invasive outpatient procedure. Nowadays almost 90% of the surgical treatment of VUR in Sweden is done by endoscopic procedure. In the current article, our aim was to review how the endoscopic treatment of VUR developed.

Antenatal retinoic acid administration increases trophoblastic retinol-binding protein dependent retinol transport in the nitrofen model of congenital diaphragmatic hernia.

BACKGROUND: Low pulmonary retinol levels and disrupted retinoid signaling pathway (RSP) have been implicated in the pathogenesis of congenital diaphragmatic hernia (CDH) and associated pulmonary hypoplasia (PH). It has been demonstrated that nitrofen disturbs the main retinol-binding protein (RBP)-dependent trophoblastic retinol transport. Several studies have demonstrated that prenatal treatment with retinoic acid (RA) can reverse PH in the nitrofen-induced CDH model. We hypothesized that maternal administration of RA can increase trophoblastic RBP-dependent retinol transport in a nitrofen model of CDH. METHODS: Pregnant rats were treated with nitrofen or vehicle on gestational day 9 (D9) and sacrificed on D21. RA was given i.p. on D18, D19, and D20. Retinol and RA levels were measured using high-performance liquid chromatography. Immunohistochemistry was performed to evaluate trophoblastic expression of RBP. Expression levels of the primary RSP genes were determined using quantitative real-time PCR and immunohistochemistry. RESULTS: Markedly increased trophoblastic RBP immunoreactivity was observed in CDH+RA compared to CDH. Significantly increased serum and pulmonary retinol and RA levels were detected in CDH+RA compared to CDH. Pulmonary expression of RSP genes and proteins were increased in CDH+RA compared to CDH. CONCLUSION: Increased trophoblastic RBP expression and retinol transport after antenatal administration of RA suggest that retinol-triggered RSP activation may attenuate CDH-associated PH by elevating serum and pulmonary retinol levels.

Expression of hepatic lipid droplets is decreased in the nitrofen model of congenital diaphragmatic hernia.

BACKGROUND: Prenatal mortality in newborn infants with congenital diaphragmatic hernia (CDH) has been attributed to increased amounts of liver hernia ion through the diaphragmatic defect. Antenatal studies in human and rodent fetus with CDH further demonstrated a contribution of the developing liver in the pathogenesis of CDH. The abnormal hepatic growth in experimental animal models, therefore, indicates a disruption of normal liver development in CDH. However, the underlying structural, histological and functional changes in the liver of animals with CDH remain unclear. We design this study to test the hypothesis that the morphological and cellular liver development is altered in the nitrogen-induced CDH model. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Livers and chest were harvested on D21 and divided into two groups: control (n = 8), nitrofen with CDH (CDH, n = 8). Haematoxylin-eosin (Straub et al. Histopathology 68:617-631, 2013) staining was performed to evaluate underlying morphological changes. Apoptosis was checked by using TUNEL staining and apoptotic cell number was counted on 16-16 slides in 25 fields by two independent viewers. Hepatic lipid droplet expressions were evaluated by hepatic adipose differentiation-related protein (ARDP) expression. RESULTS: Compared to controls markedly increased hypertrophy was seen in CDH group. Significantly increased apoptotic cell numbers were detected in CDH group compared to controls (5.1 ± 1.5 vs 2.1 ± 0.6) (p < 0.05). The relative mRNA expression levels of ARDP were significantly reduced in CDH group compared to controls. Immunohistochemistry showed markedly decreased hepatic ADRP immunoreactivity in CDH fetuses compared to controls. CONCLUSIONS: Our findings provide strong evidence of hepatic hypertrophy and increased cell apoptosis in the liver of nitrofen-induced CDH. These morphological changes may affect liver lipid droplet expression function.

Decidual ß-carotene-15,15'-oxygenase-1 and 2 (BCMO1,2) expression is increased in nitrofen model of congenital diaphragmatic hernia.

BACKGROUND: Retinoids are essential for fetal and lung development. Beta-carotene(BC) is the main dietary retinoid source and beta-carotene-15,15'-oxygenase-1 and 2 (Bcmo1,2) is the primary enzyme generating retinoid from BC in adult mammalian tissues. Placenta has a major role in the retinol homeostasis in fetal life: Since there is no fetal retinol synthesis, maternal retinol has to cross the placenta. It has been recently shown that BC can be converted to retinol by Bcmo1,2 in placenta for retinol transfer and moreover, BC can cross the placenta intact. The placental Bcmo1,2 expression is tightly controlled by placental retinol level. In severe retinol deficiency it has been shown that placental Bcmo1,2 expression are increased for generating retinol from dietary maternal BC even when the main retinol transfer is blocked. In recent years, low pulmonary retinol levels and disrupted retinoid signaling pathway have been implicated in the pathogenesis of pulmonary hypoplasia and congenital diaphragmatic hernia (CDH) in the nitrofen model of CDH. Recently, it has been demonstrated that the main retinol transfer in the placenta is blocked in the nitrofen model of CDH causing increased placental and decreased serum retinol level. The aim of our study was to determine maternal and fetal ß-carotene levels and to investigate the hypothesis that placental expression of BCMO1 and BCMO2 is altered in nitrofen-exposed rat fetuses with CDH. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Maternal and fetal serum, placenta, liver and left lungs were harvested on D21 and divided into two groups: control (n = 8) and nitrofen with CDH (n = 8). Immunochistochemistry was performed to evaluate trophoblasts by cytokeratin expression and placental Bcmo1,2 expression. Expression levels of Bcmo1,2 genes in fetal lungs and liver were determined using RT-PCR and immunohistochemistry. BC level was measured using HPLC. RESULTS: Markedly increased decidual Bcmo1,2 immunoreactivity was observed in CDH group compared to controls. There was no difference neither in the trophoblastic Bcmo1,2 immunoreactivity nor in the pulmonary and liver Bcmo1,2 expression compared to controls. There was no significant difference in maternal serum BC levels between control and CDH mothers (2.14 ± 0.55 vs 2.56 ± 1.6 µM/g, p = 0.8). BC was not detectable neither in the fetal serum nor liver or lungs. CONCLUSIONS: Our data show that nitrofen increases maternal but not fetal Bcmo1,2 expression in the placenta in nitrofen-induced CDH group. The markedly increased decidual Bcmo1,2 expression suggests that nitrofen may trigger local, decidual retinol synthesis in the nitrofen model of CDH.

Prenatal administration of retinoic acid increases the trophoblastic insulin-like growth factor 2 protein expression in the nitrofen model of congenital diaphragmatic hernia.

BACKGROUND: The high mortality rate in congenital diaphragmatic hernia (CDH) is attributed to pulmonary hypoplasia (PH). Insulin-like growth factor 2 (IGF2) is an important regulator of fetal growth. The highest levels of IGF2 expression are found in the placenta, which are negatively regulated by decidual retinoid acid receptor alpha (RARα). It has been demonstrated that prenatal administration of retinoic acid (RA) suppresses decidual RARα expression. Previous studies have further shown that prenatal administration of RA can reverse PH in nitrofen-induced CDH model. In IGF2 knockout animals, low levels of IGF2 are associated with decreased placental growth and PH. We therefore hypothesized that nitrofen decreases trophoblastic IGF2 expression and prenatal administration of RA increases it through decidual RARα in the nitrofen-induced CDH model. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). RA was given intraperitoneally on D18, D19 and D20. Fetuses were harvested on D21 and divided into three groups: control, CDH and nitrofen+RA. Immunohistochemistry was performed to evaluate decidual RARα and trophoblastic IGF2 expression. Protein levels of IGF2 in serum, intra-amniotic fluid and left lungs were measured by enzyme-linked immunosorbent assay. RESULTS: Significant growth retardation of placenta and left lungs was observed in the CDH group compared to control and nitrofen+RA group. Markedly increased decidual RARα and decreased IGF2 immunoreactivity were found in the CDH group compared to control and nitrofen+RA group. Significantly decreased IGF2 protein levels were detected in serum, intra-amniotic fluid and left lungs in the CDH group compared to control and nitrofen+RA group. CONCLUSION: Our findings suggest that nitrofen may disturb trophoblastic IGF2 expression through decidual RARα resulting in retarded placental growth and PH in the nitrofen-induced CDH. Prenatal administration of RA may promote lung and placental growth by increasing trophoblastic IGF2 expression.

Nitrofen increases total retinol levels in placenta during lung morphogenesis in the nitrofen model of congenital diaphragmatic hernia.

BACKGROUND: It has been shown that pulmonary retinol level is decreased during lung morphogenesis in the nitrofen-induced PH in congenital diaphragmatic hernia (CDH). Placenta has a major role in the retinol homeostasis in fetal life. Since there is no fetal retinol synthesis, maternal retinol has to cross the placenta. Placenta is the main fetal retinol store where retinol is stored in retinyl-ester formation. Trophoblasts have to produce its own retinol-binding protein (RBP) for retinol transport from placenta to fetus. Recently, we demonstrated that trophoblastic RBP expression is decreased in the nitrofen model of CDH. The aim of this study was to investigate the retinol transfer from mother to the placenta in nitrofen model of CDH. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetal placenta harvested on D21 and divided into two groups: control (n = 11) and nitrofen with CDH (n = 11). Retinoid levels in placenta were measured using HPLC. Immunohistochemistry was performed to evaluate trophoblastic expression of main RSP genes. RESULTS: Total retinol levels in the placenta were significantly increased in CDH placenta compared to control placenta. The retinyl-ester levels were significantly increased in CDH placenta compared to control placenta. Markedly, decreased immunoreactivity of retinoid signaling pathway was observed in trophoblast cells in CDH compared to control placenta. CONCLUSIONS: Increased placental retinol levels show that retinol is transferred from mother to placenta and stored in the placenta in nitrofen model of CDH during lung morphogenesis. Nitrofen may disturb the mobilization of retinol from placenta to fetal circulation causing PH in CDH.

Prenatal administration of all-trans retinoic acid upregulates leptin signaling in hypoplastic rat lungs with experimental congenital diaphragmatic hernia.

PURPOSE: Pulmonary hypoplasia (PH), characterized by alveolar immaturity, is one of the leading causes of respiratory insufficiency in newborns with congenital diaphragmatic hernia (CDH). Leptin (Lep) and its receptor (Lep-R) play an important role in fetal lung growth by stimulating alveolar differentiation and maturation. Lep and Lep-R are strongly expressed by alveolar cells during the saccular stage of fetal lung development. Lep-deficient mice exhibit decreased alveolarization with reduced pulmonary surfactant phospholipid synthesis, similar to human and nitrofen-induced PH. Prenatal administration of all-trans retinoic acid (ATRA) has been shown to stimulate alveolarization in nitrofen-induced PH. Recent studies have demonstrated that Lep and Lep-R expression in developing lungs is regulated by ATRA. We hypothesized that prenatal treatment with ATRA increases pulmonary Lep and Lep-R expression in the nitrofen model of CDH-associated PH. METHODS: Time-mated rats received either 100 mg nitrofen or vehicle via oral-gastric lavage on embryonic day 9.5 (E9.5). Control and nitrofen-exposed dams were randomly assigned to either intraperitoneal ATRA (5 mg/kg/d) or placebo administration on E18.5, E19.5 and E20.5. Fetal lungs were harvested on E21.5, and divided into Control+Placebo, Control+ATRA, Nitrofen+Placebo and Nitrofen+ATRA. Alveolarization was assessed using stereo- and morphometric analysis techniques. Surfactant phospholipid synthesis was analyzed by labeling for surfactant protein B (SP-B). Pulmonary gene expression levels of Lep and Lep-R were determined using quantitative real-time polymerase chain reaction. Immunohistochemical staining for Lep and Lep-R was performed to evaluate alveolar protein expression and localization. RESULTS: In vivo administration of ATRA resulted in significantly increased lung-to-body weight ratio with enhanced radial alveolar count and decreased mean linear intercept compared to placebo treatment. Immunofluorescence analysis demonstrated markedly increased pulmonary SP-B expression in Nitrofen+ATRA compared to Nitrofen+Placebo. Relative mRNA expression of Lep and Lep-R was significantly increased in Nitrofen+ATRA compared to Nitrofen+Placebo. Lep and Lep-R immunoreactivity was markedly increased in interstitial and alveolar epithelial cells of Nitrofen+ATRA compared to Nitrofen+Placebo. CONCLUSION: Increased Lep and Lep-R expression after prenatal administration of ATRA in nitrofen-induced PH suggests that ATRA may have therapeutic potential in attenuating CDH-associated PH by stimulating alveolarization and de novo surfactant production.

Appendicitis in obese children.

During the past two decades, the incidence of childhood obesity has increased at alarming rates throughout the world. Obesity is associated with a variety of physiological changes that may impair a patient's response to surgery. With the rising rates of childhood obesity, pediatric surgeons must appreciate differences in the management and outcomes of these patients. Difficult physical examination, elevated inflammatory blood markers, and negative influence of obesity on the detection rate of the appendix on ultrasound have been reported causing diagnostic challenging of appendicitis in obese children. Moreover, obesity is associated with longer hospital stay and higher morbidity and minimal invasive techniques' superior outcomes over open technique in children undergoing appendectomy.

Increased trophoblastic apoptosis mediated by neutrophil gelatinase-associated lipocalin (NGAL) activation in the nitrofen model of congenital diaphragmatic hernia.

BACKGROUND: Retinoids play a key role in fetal lung development. It has been suggested that the maternal-fetal retinol transport is disrupted by trophoblastic apoptosis. The mechanism underlying nitrofen-induced apoptosis in placenta is not fully understood. Neutrophil gelatinase-associated lipocalin (NGAL) is expressed in the fetal part of the maternal-fetal interface. NGAL is part of the immune barrier and serves primarily as a transport protein transferring biologically hazardous molecules in a safe and controlled way. It has been shown that over-activation of NGAL induces apoptosis. We hypothesized that increased placental NGAL expression induces trophoblastic apoptosis in the nitrofen model of CDH. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Placenta harvested on D21 and divided into two groups: control and nitrofen with CDH. Immunohistochemistry was performed to evaluate trophoblasts (by cytokeratin expression), NGAL expression, and apoptotic trophoblastic cells (using TUNEL assay). Total RNA was extracted from each placenta and the relative mRNA expression levels of NGAL were analyzed using RT-PCR. RESULTS: Immunohistochemistry showed NGAL immunoreactivity both in control and CDH in the fetal part of the fetal-maternal interface of placenta. Markedly increased NGAL expression was detected in CDH group compared to controls. Relative mRNA expression levels of NGAL gene were significantly increased in the CDH group compared to control in the placenta (5.924 ± 0.93 vs. 1.895 ± 0.54, p < 0.001). Markedly increased numbers of apoptotic trophoblastic cells were seen in the maternal-fetal interface in the CDH group compared to controls. CONCLUSIONS: NGAL activation may lead to increased trophoblastic apoptosis in the maternal-fetal interface in the nitrofen model of CDH. These changes may therefore cause disturbance in maternal-fetal retinol transport affecting fetal lung morphogenesis.

Pulmonary FGF-18 gene expression is downregulated during the canalicular-saccular stages in nitrofen-induced hypoplastic lungs.

PURPOSE: Pulmonary hypoplasia (PH) associated with congenital diaphragmatic hernia (CDH) represents one of the major challenges in neonatal intensive care. However, the molecular pathogenesis of PH is still poorly understood. In developing fetal lungs, fibroblast growth factor 18 (FGF-18) plays a crucial role in distal airway maturation. FGF-18 knockouts show smaller lung sizes with reduced alveolar spaces and thicker interstitial mesenchymal compartments, highlighting its important function for fetal lung growth and differentiation. We hypothesized that pulmonary FGF-18 gene expression is downregulated during late gestation in nitrofen-induced hypoplastic lungs. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetuses were harvested on D18 and D21, and lungs were divided into three groups: controls, hypoplastic lungs without CDH [CDH(-)], and hypoplastic lungs with CDH [CDH(+)] (n = 24 at each time-point). Pulmonary FGF-18 gene expression levels were analyzed by qRT-PCR. Immunohistochemistry was performed to investigate FGF-18 protein expression/distribution. RESULTS: Relative mRNA levels of pulmonary FGF-18 gene expression were significantly decreased in CDH(-) and CDH(+) on D18 and D21 compared to controls (p < 0.05 and p < 0.01, respectively). Immunoreactivity of FGF-18 was markedly diminished in mesenchymal cells surrounding the airway epithelium on D18 and D21 compared to controls. CONCLUSION: Downregulation of FGF-18 gene expression in nitrofen-induced hypoplastic lungs suggests that decreased FGF-18 expression during the canalicular-saccular stages may interfere with saccular-alveolar differentiation and distal airway maturation resulting in PH.