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.

Urinary Tract Infection in Children: Management in the Era of Antibiotic Resistance-A Pediatric Urologist's View.

CONTEXT: Antibiotic resistance to uropathogens has grown significantly worldwide. Today, pediatric urologist experience a situation that needs appropriate action because urinary tract infections are one of the most common bacterial infections in children. OBJECTIVE: In this overview we aimed at presenting the clinical aspects of antibiotic usage in pediatric urology. Our intention was to take part of the important debate regarding future management of bacterial resistance against antibiotics. EVIDENCE ACQUISITION: We searched PubMed for the terms: [UTI in children], [Recurrent UTI in children], and [Antibiotic resistance in UTI]. When using these terms, we found a numerous amount (3875) of published clinical articles related to the topic. By means of an overview, we chose not to focus on a specific condition but to an overall understanding of the problems related to pediatric urology in general. EVIDENCE SYNTHESIS: We found that usage of antibiotics has had an unquestionable benefit to reduce the morbidity and mortality related to urinary tract infections in childhood. However, recent studies suggest that early exposure to antibiotics in childhood might have negative systemic effects related to neurocognitive function, body metabolism, and fat distribution. In addition to increased resistance to common antimicrobial agents, it has resulted in increased costs and inadequate effect in severe infections. This calls for changes in the clinical management of urinary pathogens in pediatric urology. CONCLUSIONS: As the prevalence of antibiotic resistance grows, pediatric urologists have a key role in managing its consequences and its prevention. PATIENT SUMMARY: In this overview we looked at the consequences of antibiotic usage treating urinary tract infections in childhood. We found that the prevalence of antibiotic resistance has grown. We concluded that decision-makers must know about the short- and long-term effects of antibiotic usage in children. When we understand the development of antibiotic resistance better, we can build up prevention strategies.

Comments to Recent Guidelines on Undescended Testis.

During the past couple of decades, our understanding of the treatment of undescended testis (UDT) has hugely expanded and it is still dynamically changing: new diagnostic tools are available, and experimental procedures are becoming a real-life treatment options. Our community needs to continuously update our guidelines. It is also our responsibility to build up, not a uniform, but a patient-oriented guideline which can provide information for both primary care providers and pediatric surgeons. Here, in Europe, we endeavor to change the different national guidelines to one common European pediatric surgical guideline in the treatment of UDT.

Gonadoblastoma in patients with 45,X/46,XY mosaicism: A 16-year experience.

BACKGROUND: It is recognised that individuals with a 45,X/46,XY karyotype, known as Turner mosaic syndrome with Y chromosome material (TMSY), have an increased risk of developing gonadoblastoma (GB), which may then devolve into one of a number of germ cell malignancies. Hence, children with TMSY are usually recommended to undergo prophylactic gonadectomy. OBJECTIVE: We designed this study to describe the phenotypic features of our series of children with TMSY who underwent prophylactic gonadectomy in order to evaluate the prevalence of GB and germ cell malignancies in their resected specimens. STUDY DESIGN: This is a retrospective case series wherein we comprehensively reviewed the clinical, histological, and cytogenetic features of all patients who underwent prophylactic gonadectomy at three tertiary paediatric referral centres over 16 years. Cases were identified from surgical logbooks and through the institutional histopathology database. Data were collected with particular reference to clinical phenotype, predominant karyotype cell line, operative management, anatomical findings and the presence of neoplastic changes. RESULTS: Fourteen children ranging in age at the time of surgery from 2 weeks to 17 years were included in the series. Eleven children were reared as females. The three children who were reared as males had severe penoscrotal hypospadias. The 46,XY cell line was the predominant cell line in seven (50%) cases in blood lymphocytes. The resected specimens from four patients (28.6%) contained GB, with three patients having bilateral GB. This sub-group of patients with GB were aged 5 months, 48 months, 71 months, and 13 years. GB arose in one patient with and three patients without genital virilisation. There was no focus of invasive germ cell tumour in any specimen. DISCUSSION: GB may be present in infants with TMSY as young as 5 months, even with low levels of Y chromosome material. The prevalence of GB in prophylactic gonadectomy specimens is similar to many previously reported series, although the absence of dysgerminoma in our series is reassuring. The exclusive presence of GB in intra-abdominal gonads is in keeping with the findings of several other series. CONCLUSION: Owing to the presence of gonadoblastoma in the gonads of children with TMSY as young as 5 months, we recommend that all patients with intra-abdominal gonads in the context of TMSY should duly undergo prophylactic gonadectomy, although the timing of such surgery can be discussed with parents during counselling regarding the risk of malignancy.

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 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.

Increased uptake of dietary retinoids at the maternal-fetal barrier in the nitrofen model of congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: The retinol signaling pathway is disrupted in congenital diaphragmatic hernia (CDH). Since there is no fetal retinol synthesis, maternal retinol has to cross the placenta. Nitrofen interferes with the retinol-binding protein (RBP) transfer pathway in CDH. However, in RBP knockout mice, retinol has been shown to be present. In this model, increased uptake of maternal dietary retinyl ester (RE) bounded in low-dense-lipoprotein (LDL) through low-density-lipoprotein-receptor 1 (LRP1) and increased activity of RE hydrolysis by lipoprotein-lipase (LPL) have been found. The aim of this study was to investigate the RE transfer pathway in the nitrofen CDH model. METHODS: Pregnant rats were treated with nitrofen or vehicle on gestational day (D9) and sacrificed on D21. Immunohistochemistry was performed to evaluate LRP1 and LPL protein expression. Serum LDL levels were measured by ELISA. Pulmonary and serum retinoid levels were measured using HPLC. RESULTS: Markedly increased trophoblastic and pulmonary LRP1 and LPL immunoreactivity were observed in CDH compared to controls. Significantly increased serum LDL and RE levels were observed in CDH compared to controls. CONCLUSIONS: The increased uptake of dietary retinoids at the maternal-fetal barrier in the nitrofen CDH model suggests that the RE transfer pathway may be the main source of retinol in this model.

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 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.

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.

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.

Single center experience with endoscopic subureteral dextranomer/hyaluronic acid injection as first line treatment in 1,551 children with intermediate and high grade vesicoureteral reflux.

PURPOSE: In recent years the endoscopic injection of dextranomer/hyaluronic acid has become an established alternative to long-term antibiotic prophylaxis and the surgical management of vesicoureteral reflux. We determined the safety and effectiveness of the endoscopic injection of dextranomer/hyaluronic acid as first line treatment for high grade vesicoureteral reflux. MATERIALS AND METHODS: Between 2001 and 2010, 1,551 children (496 male, 1,055 female, median age 1.6 years) underwent endoscopic correction of intermediate and high grade vesicoureteral reflux using dextranomer/hyaluronic acid soon after the diagnosis of vesicoureteral reflux on initial voiding cystourethrogram. Vesicoureteral reflux was unilateral in 761 children and bilateral in 790. Renal scarring was detected in 369 (26.7%) of the 1,384 patients who underwent dimercapto-succinic acid imaging. Reflux grade in the 2,341 ureters was II in 98 (4.2%), III in 1,340 (57.3%), IV in 818 (34.9%) and V in 85 (3.6%). Followup ultrasound and voiding cystourethrogram were performed 3 months after the outpatient procedure, and renal ultrasound was performed annually thereafter. Patients were followed for 3 months to 10 years (median 5.6 years). RESULTS: Vesicoureteral reflux resolved after the first, second and third endoscopic injection of dextranomer/hyaluronic acid in 2,039 (87.1%), 264 (11.3%) and 38 (1.6%) ureters, respectively. Febrile urinary tract infections developed during followup in 69 (4.6%) patients. None of the patients in the series needed reimplantation of ureters or experienced any significant complications. CONCLUSIONS: Our results confirm the safety and efficacy of the endoscopic injection of dextranomer/hyaluronic acid in the eradication of high grade vesicoureteral reflux. We recommend this 15-minute outpatient procedure as the first line of treatment for high grade vesicoureteral reflux.

Pax3 gene expression is not altered during diaphragmatic development in nitrofen-induced congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Malformations of the pleuroperitoneal folds (PPFs) have been identified as the origin of the diaphragmatic defect in congenital diaphragmatic hernia (CDH). Pax3, expressed in muscle precursor cells (MPCs), plays a key role in regulating myogenesis and muscularization in the fetal diaphragm. Pax3 mutant mice display absence of muscular diaphragm. However, the distribution of muscle precursor cells is reported to be normal in the PPF of the nitrofen-CDH model. We designed this study to investigate the hypothesis that Pax3 gene expression is unaltered in the PPF and developing diaphragm in the nitrofen-induced CDH model. METHODS: Pregnant rats were treated with nitrofen or vehicle on gestational day (D) 9 and sacrificed on D13, D18, and D21. Pleuroperitoneal folds (D13) and developing diaphragms (D18 and D21) were dissected, total RNA was extracted, and real-time quantitative polymerase chain reaction was performed to determine Pax3 messenger RNA levels. Confocal immunofluorescence microscopy was performed to evaluate protein expression/distribution of Pax3. RESULTS: Relative messenger RNA expression levels of Pax3 in PPFs and developing diaphragms were not significantly different in the nitrofen group compared with controls. Intensity of Pax3 immunofluorescence was also not altered in PPFs and developing diaphragms of the nitrofen group compared with controls. CONCLUSION: Pax3 gene expression is not altered in the PPFs and developing diaphragm of nitrofen-CDH model, suggesting that the diaphragmatic defect is not caused by disturbance of myogenesis and muscularization.

Alterations of peroxisome proliferator-activated receptor γ and monocyte chemoattractant protein 1 gene expression in the nitrofen-induced hypoplastic lung.

BACKGROUND/PURPOSE: Peroxisome proliferator-activated receptor γ (PPARγ) plays a key role in normal lung development. Peroxisome proliferator-activated receptor γ messenger RNA (mRNA) is detectable at 18 days of gestation in fetal rat lungs, and levels peak just before birth. Peroxisome proliferator-activated receptor γ agonists are reported to stimulate lung development, whereas inhibition of PPARγ disrupts postnatal lung maturation. Monocyte chemoattractant protein 1 (MCP-1), which is inhibited by PPARγ, is reported to disrupt late lung morphogenesis. This study was designed to investigate the hypothesis that PPARγ expression is downregulated and that MCP-1 expression is upregulated during the late stages of lung development in nitrofen-induced hypoplastic lungs. METHODS: Pregnant rats were treated with nitrofen or vehicle on D9. RNA was extracted from fetal lungs (D18 and D21), and relative mRNA expression levels of PPARγ and MCP-1 were determined by reverse transcriptase-polymerase chain reaction. Immunohistochemistry was performed to evaluate protein expression/distribution of PPARγ and MCP-1. RESULTS: Relative mRNA expression levels of PPARγ were significantly downregulated in the nitrofen group compared with controls on D21, whereas MCP-1 levels were upregulated. Immunohistochemical study showed markedly decreased PPARγ and increased MCP-1 immunoreactivity in the nitrofen-induced hypoplastic lungs compared with controls on gestational day 21. CONCLUSION: Altered pulmonary gene expression of PPARγ and MCP-1 during late gestation may impair lung development and maturation, contributing to pulmonary hypoplasia in the nitrofen-induced congenital diaphragmatic hernia model.

Nitrofen interferes with trophoblastic expression of retinol-binding protein and transthyretin during lung morphogenesis in the nitrofen-induced congenital diaphragmatic hernia model.

BACKGROUND: Retinoids play a key role in lung development. Retinoid signaling pathway has been shown to be disrupted in the nitrofen model of congenital diaphragmatic hernia (CDH) but the exact mechanism is not clearly understood. Retinol-binding protein (RBP) and transthyretin (TTR) are transport proteins for delivery of retinol to the tissues via circulation. Previous studies have shown that pulmonary retinol levels are decreased during lung morphogenesis in the nitrofen CDH model. In human newborns with CDH, both retinol and RBP levels are decreased. It has been reported that maternal RBP does not cross the placenta and the fetus produces its own RBP by trophoblast. RBP and TTR synthesized in the fetus are essential for retinol transport to the developing organs including lung morphogenesis. We hypothesized that nitrofen interferes with the trophoblastic expression of RBP and TTR during lung morphogenesis and designed this study to examine the trophoblastic expression of RBP and TTR, and the total level of RBP and TTR in the lung in the nitrofen model of CDH. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetal lungs and placenta harvested on D21 and divided into two groups: control (n = 8) and nitrofen with CDH (n = 8). Total lung RBP and TTR levels using protein extraction were compared with enzyme linked immunoassay (ELISA). Immunohistochemistry was performed to evaluate trophoblastic RBP and TTR expression. RESULTS: Total protein levels of lung RBP and TTR were significantly lower in CDH (0.26 ± 0.003 and 6.4 ± 0.5 µg/mL) compared with controls (0.4 ± 0.001 and 9.9 ± 1.6 µg/mL, p < 0.05). In the control group, immunohistochemical staining showed strong immunoreactivity of RBP and TTR in the trophoblast compared to CDH group. CONCLUSIONS: Decreased trophoblast expression of retinol transport proteins suggest that nitrofen may interfere with the fetal retinol transport resulting in reduced pulmonary RBP and TTR levels and causing pulmonary hypoplasia in CDH.

Smad1 and WIF1 genes are downregulated during saccular stage of lung development in the nitrofen rat model.

PURPOSE: The exact pathogenesis of pulmonary hypoplasia in the nitrofen-induced congenital diaphragmatic hernia (CDH) still remains unclear. Smad1, one of the bone morphogenesis protein (BMP) receptor downstream signaling proteins, plays a key role in organogenesis including lung development and maturation. Smad1 knockout mice display reduced sacculation, an important feature of pulmonary hypoplasia. Wnt inhibitor factor 1 (Wif1) is a target gene of Smad1 in the developing lung epithelial cells (LECs). Smad1 directly regulates Wif1 gene expression and blockade of Smad1 function in fetal LECs is reported to downregulate Wif1 gene expression. We designed this study to test the hypothesis that pulmonary Smad1 and Wif1 gene expression is downregulated during saccular stage of lung development in the nitrofen CDH model. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetuses were harvested on D18, and D21. Fetal lungs were dissected and divided into 2 groups: control and nitrofen (n = 9 at each time point, respectively). Pulmonary gene expression of Smad1 and Wif1 were analyzed by real-time RT-PCR. Immunohistochemistry was performed to evaluate protein expression/distribution of Smad1 and Wif1. RESULTS: The relative mRNA expression levels of Smad1 and Wif1 were significantly downregulated in the nitrofen group compared to controls on D18 and D21 (*p < 0.01, **p < 0.05). Immunoreactivity of Smad1 and Wif1 was also markedly decreased in nitrofen lungs compared to controls on D18 and D21. CONCLUSION: We provide evidence, for the first time, that the pulmonary gene expression of Smad1 and Wif1 is downregulated on D18 and D21 (saccular stage of lung development) in the nitrofen-induced hypoplastic lung. These findings suggest that the downregulation of Smad1/Wif1 gene expression may contribute to pulmonary hypoplasia in the nitrofen CDH model by retardation of lung development during saccular stage.

Upregulation of fibroblast growth factor receptor 2 and 3 in the late stages of fetal lung development in the nitrofen rat model.

PURPOSE: Nitrofen model of congenital diaphragmatic hernia (CDH) has been widely used to investigate the pathogenesis of pulmonary hypoplasia (PH). Fibroblast growth factor (FGF) signaling pathway plays a fundamental role in fetal lung development. FGF7 and FGF10, which are critical for lung morphogenesis, have been reported to be downregulated in nitrofen-induced PH. FGF signaling is mediated by a family of four single transmembrane receptors, FGFR1-4. FGFR2 and FGFR3 have been shown to be expressed predominantly in the late stages of developing lungs. In addition, the upregulation of FGFR2 gene expression has been associated with severe defects in lung development and resulted in arrested alveologenesis similar to PH seen in the nitrofen model. Furthermore, FGFR3(-/-)FGFR4(-/-) double mutants showed thinner mesenchyme and larger air spaces. We designed this study to test the hypothesis that FGFR gene expression is upregulated in the late stages of lung development in the nitrofen CDH model. METHODS: Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Cesarean section was performed and fetuses were harvested on D18 and D21. Fetal lungs were divided into three groups: control, nitrofen without CDH [CDH(-)], and nitrofen with CDH [CDH(+)] (n = 24 at each time-point). Pulmonary gene expression levels of FGFR1-4 were analyzed by real-time RT-PCR. Immunohistochemistry was also performed to evaluate protein expression/distribution at each time-point. RESULTS: The relative messenger RNA expression levels of pulmonary FGFR2 and FGFR3 on D21 were significantly increased in CDH(-) (6.38 ± 1.93 and 7.84 ± 2.86, respectively) and CDH(+) (7.09 ± 2.50 and 7.25 ± 3.43, respectively) compared to controls (P < 0.05 and P < 0.01, respectively), whereas no significant alteration was observed on D18. There were no differences in FGFR1 and FGFR4 expression at both time-points. Increased immunoreactivity of FGFR2 and FGFR3, mainly in the distal epithelium and mesenchyme, was observed in the nitrofen-induced hypoplastic lungs on D21 compared to controls. CONCLUSION: Upregulation of FGFR2 and FGFR3 pulmonary gene expression in the late stages of fetal lung development may disrupt FGFR-mediated alveologenesis resulting in PH in the CDH model.