Subtle renal duplication as an unrecognized cause of childhood incontinence: diagnosis by magnetic resonance urography

Urinary incontinence in young girls who have been toilet trained may be due to an ectopic ureter inserting below the urinary sphincter. This diagnosis is frequently delayed, is psychologically distressing, and may be missed at physical examination. Findings at ultrasound evaluation may be subtle and imaging with computed tomography or intravenous urography exposes young patients to ionizing radiation. We report two cases of girls with urinary incontinence where magnetic resonance (MR) urography revealed subtle renal duplication which implied the presence of an ectopic duplicated ureter with infrasphincteric insertion. These cases stress the importance of examining the kidneys, rather than the perineum, at MR, ultrasound and intravenous urogram evaluation, and show the value of MR urography as a safe alternative to computed tomography and intravenous urography for making this diagnosis.

Mutations of CXorf6 are associated with a range of severities of hypospadias

OBJECTIVE

Mutations in chromosome X open reading frame 6 (CXorf6), a recently described candidate gene involved in the development of male genitalia, have been found in patients with complex 46,XY disorders of sexual development (46,XY DSD) including micropenis, bifid scrotum, and penoscrotal hypospadias. The objective of this work was to identify genomic variants of CXorf6 in patients with isolated hypospadias, severe or non-severe.

DESIGN AND METHODS

Forty-one patients with glandular to perineal hypospadias and thirty controls were studied. Direct sequencing for coding exons 3-6 of CXorf6 and their flanking splice sites was performed on DNA extracted from foreskin collected from surgery. Secondary and tertiary structures of the protein were predicted using NNpredict and Protein Homology/analogY Recognition Engine engines.

RESULTS

Four mutations (9.7% of cases) were identified. One missense mutation (1295T>C, V432A) and two deletions (325delG, predicted to cause a stop codon L121X) occurred in patients with penoscrotal and proximal hypospadias. One patient with subcoronal hypospadias had CAG-repeat amplification in the second polyglutamine domain of CXorf6. Secondary structure prediction indicated that this insertion occurred in a helix element of the protein. The tertiary structure prediction showed an alteration of the shape of the protein and crowding between domains.

CONCLUSION

CXorf6 mutations are associated with isolated hypospadias of varying severity. However, the pathophysiology of these mutations and the function of the CXorf6 gene product remain to be investigated.

Hydrocele in the pediatric patient: inguinal or scrotal approach?

PURPOSE

The recommended approach for repairing hydrocele in children is inguinal to address a patent processus vaginalis. Hydrocele repair in adults is performed with a scrotal incision. We identified an age above which a significant percent of children had noncommunicating hydroceles, justifying a scrotal approach.

MATERIALS AND METHODS

A retrospective chart review was performed of children undergoing hydrocele repair at our institution between 1998 and 2006. Operative reports were reviewed by 2 investigators and intraoperative findings were recorded for statistical analysis relating age and findings at the time of the procedure using logistic regression and ROC analysis. Laterality and recurrence rates were also noted.

RESULTS

In this retrospective chart review 82.1% of hydroceles in children older than 10 years had intraoperative findings consistent with noncommunicating hydrocele and 86.4% in children older than 12 years were noncommunicating. One hydrocele in the age group older than 12 years was communicating and the history was suggestive of communication. Age was significantly associated with a patent processus vaginalis (OR 0.783, p <0.0001).

CONCLUSIONS

It is possible in children older than 12 years to repair hydroceles through a scrotal incision unless the clinical history is suggestive of a communication. Children younger than 12 years should undergo inguinal exploration for hydrocele repair.

3-dimensional neuroanatomy of the human fetal pelvis: anatomical support for partial urogenital mobilization in the treatment of urogenital sinus

PURPOSE

Retrospective reviews suggest that the functional outcomes of surgery of the urogenital sinus have often been unsatisfactory and to our knowledge the long-term results of newer surgical techniques have yet to be evaluated. A precise understanding of pelvic fetal neuroanatomy is germane for optimizing surgical correction of the urogenital sinus.

MATERIALS AND METHODS

The pelves of 10 human female fetuses were serially sectioned. Masson's trichrome staining and immunochemistry for the neuronal marker S100 (Dako Corp., Carpinteria, California) along with anatomical computer reconstruction allowed 3-dimensional analysis of the nerves in relation to the pelvic structures as an animated motion picture.

RESULTS

Two types of neuronal structures were identified. 1) A dense perivisceral foil of branching nerves closely surrounded the pelvic organs. The localization of most nerves was on the external faces of the viscera with a limited fraction in the rectovaginal and urethrovaginal septa. This innervation was from the anterior cephalad periurethral area to the posterior caudal perirectal area. 2) A significant amount of nerves surrounded the cephalad urethra on its anterior and posterior faces.

CONCLUSIONS

Based on these anatomical data during surgical repair of a urogenital sinus we would advocate minimal mobilization of the lateral faces of the vagina, avoiding dissection of the proximal urethra above the pubic bone and electing a vaginal flap in severe cases.

Associations among hypospadias, cryptorchidism, anogenital distance, and endocrine disruption

Endocrine disruptors, such as environmental compounds with endocrine-altering properties, may cause hypospadias and cryptorchidism in several species, including humans. Anogenital distance is sexually dimorphic in many mammals, with males having longer anogenital distance on average than females. Animal models of proposed endocrine disruptors have associated prenatal exposure with hypospadias, cryptorchidism, and reduced anogenital distance. Human studies have correlated shorter anogenital distance to in utero exposure to putative endocrine disruptors. We review preliminary data suggesting that anogenital distance is reduced in boys with hypospadia and cryptorchidism. Hence, human hypospadias and cryptorchidism may be associated with reduced anogenital distance as a result of endocrine disruption.

Endocrine disruptors, genital development, and hypospadias

Hypospadias is one of the most common congenital anomalies in the United States, occurring in approximately 1 in 125 live male births. Embryological studies have demonstrated that, depending on where the urethral development arrests, the meatal opening can be anywhere along the shaft of the penis or, in more severe forms, within the scrotum or in the perineum. Currently, the only available treatment is surgery. If left uncorrected, especially in its severe form, there is risk of infertility and psychological effects, such as avoidance of intimate relationships. The cause of hypospadias is largely unknown; however, current epidemiology and laboratory studies have shed new light into the etiology of hypospadias. With recent advancements in molecular biology and microarray technology, it appears that hypospadias is potentially related to disrupted gene expression. Specifically, some of the environmental chemicals are acting as antiandrogens and interfere directly with the action of testosterone-related gene expression. In this paper, we briefly review the normal development of male external genitalia and the prevalence and environmental risk factors related to hypospadias. In addition, we discuss some of the recent laboratory findings that contribute to our current understanding of this disease.

Can we prevent hypospadias?

Hypospadias is the second most common genital anomaly in children. The etiology of hypospadias remains unknown in the overwhelming majority of patients. Herein, I review the etiology of hypospadias and propose that hypospadias can be explained by a two-hit hypothesis: genetic susceptibility plus environmental exposure to endocrine disruptors. The strategy to prevent hypospadias should be focused on (1) identifying genetic susceptibility prior to pregnancy and (2) identifying and eliminating exposure to potential toxic endocrine disruptors that effect urethral development.

Estradiol upregulates activating transcription factor 3, a candidate gene in the etiology of hypospadias

Hypospadias is a penile developmental abnormality that may partly result from in utero exposure to estrogenic compounds. Expression of activating transcription factor 3 (ATF3) is elevated in human foreskin tissue from hypospadic patients, and in utero exposure to ethinyl estradiol (17-EE) causes ATF3 upregulation in a hypospadias mouse model. We investigated the effects of in vitro exposure to EE on ATF3 expression and promoter activity in human foreskin fibroblasts using immunocytochemistry, quantitative polymerase chain reaction (PCR), western blot, and the luciferase activity assay. Immunocytochemistry showed peak positive staining at 2 hours after 0.5 to 3 hours of EE treatment (0.1 microM). Western blot showed significantly increased ATF3 protein expression (P = 0.006) after EE exposure. ATF3 mRNA, as evaluated using reverse transcriptase PCR and TaqMan real-time PCR, also increased (P = 0.146). In addition, the luciferase activity assay showed that ATF3 promoter activity was significantly enhanced after 1 hour of EE exposure (P < 0.0001). Thus, EE upregulates ATF3 expression in fibroblasts in vitro, consistent with our previous results with human tissue and in vivo mouse models. ATF3 is involved in the TGF-beta epithelial-mesenchymal signaling pathway, and its involvement in hypospadias suggests that ATF3 plays a role in development of this anomaly as a result of exposure to estrogenic compounds. Its potential involvement in other manifestations of developmental endocrine disruption is worth investigating.

Endocrine disruptors and hypospadias: role of genistein and the fungicide vinclozolin

OBJECTIVES

The phytoestrogen (plant estrogen) genistein, present in soy products, is of interest because in utero exposure to genistein can cause hypospadias in our mouse model and maternal consumption of soy is prevalent in human populations. Another compound of interest is the fungicide vinclozolin, which also causes hypospadias in the mouse and rat and can occur concurrently with genistein in the diet as a residue on exposed foods. A study in the United Kingdom found no relationship between a maternal organic vegetarian diet and hypospadias frequency, but women who consumed nonorganic vegetarian diets had a greater percentage of sons with hypospadias. Because nonorganic diets can include residues of pesticides such as vinclozolin, we sought to assess the interaction of realistic daily exposures to genistein and vinclozolin and their effects on the incidence of hypospadias.

METHODS

Pregnant mice were fed a soy-free diet and orally gavaged from gestational days 13 to 17 with 0.17 mg/kg/day of genistein, 10 mg/kg/day of vinclozolin, or genistein and vinclozolin together at the same doses, all in 100 microL of corn oil. The controls received the corn oil vehicle. The male fetuses were examined at gestational day 19 for hypospadias, both macroscopically and histologically.

RESULTS

We identified no hypospadias in the corn oil group. The incidence of hypospadias was 25% with genistein alone, 42% with vinclozolin alone, and 41% with genistein and vinclozolin together.

CONCLUSIONS

These findings support the idea that exposure to these compounds during gestation could contribute to the development of hypospadias.

In utero exposure to benzophenone-2 causes hypospadias through an estrogen receptor dependent mechanism

PURPOSE

Additives such as benzophenone-2 are commonly used in cosmetic products and food container plastics to filter out ultraviolet light. In pregnant women exposure may result in transplacental transfer of benzophenone-2 to fetuses. Benzophenone-2 is estrogenic in vitro and in the rat uterotropic assay. Estradiol causes hypospadias in mice and estrogen-like compounds are also postulated to cause hypospadias. We determined whether hypospadias would develop in male mice exposed to benzophenone-2 in utero and whether this outcome depended on estrogen receptor pathways.

MATERIALS AND METHODS

Timed pregnant C57BL/6 mice were administered benzophenone-2 (6.25 mg) or control vehicle by oral gavage from gestational days 12 through 17 and they were sacrificed on day 18. Fetuses were weighed and sexed, anogenital distance was measured and genital tubercles were harvested for paraffin sections or quantitative reverse transcriptase-polymerase chain reaction analysis of genes purportedly involved in genital tubercle development.

RESULTS

Eight of 57 benzophenone-2 treated male fetuses (14%) whose genital tubercles were examined histologically had hypospadias (p = 0.0064). Co-administration of benzophenone-2 with the estrogen receptor antagonist EM-800 resulted in normal genital tubercles, ie no hypospadias, in 26 of 26 mice. Likewise no EM-800 or control treated male genital tubercles showed hypospadias. Benzophenone-2 treated male mice had no changes in body mass adjusted anogenital distance relative to controls. Reverse transcriptase-polymerase chain reaction revealed that genital tubercles of benzophenone-2 treated male mice expressed higher levels of estrogen receptor-beta relative to male controls (p = 0.04).

CONCLUSIONS

These findings suggest that benzophenone-2 may cause hypospadias via signaling through the estrogen receptor. Further study of human benzophenone-2 exposure and its effects is needed to support this hypothesis.

A morphometric analysis of bulbar urethral strictures

In a beautifully descriptive paper, authors from Rio de Janeiro and San Francisco report a quantitative and qualitative histological analysis of spongiosal tissue in patients with bulbar urethral strictures. They found that stricture formation was characterised by major alterations in extracellular matrix features.

OBJECTIVE

To report a quantitative and qualitative histological analysis of spongiosum tissue in patients with bulbar urethral strictures.

MATERIALS AND METHODS

Urethral specimens from 15 patients who had end-to-end anastomotic urethroplasty were evaluated; the control group comprised five bulbar urethras from cadavers. The collagen content, elastic fibres, smooth muscle and vessels were analysed using stereological methods.

RESULTS

There was complete loss of the relationship between smooth muscle, extracellular matrix and sinusoids in the peri-luminal area (PLA), with collagen replacement. The extension of the fibrotic area was greater in those with a traumatic than in those with an atraumatic stricture. The content of smooth muscle and collagen in the peripheral spongiosum (PS) area was similar for the stricture and control groups, and results were comparable for traumatic and atraumatic groups and those with suprapubic cystostomy diversion or not before surgery. There was a remarkably lower vascular density in the traumatic than in the atraumatic group. There was an increase in type III collagen in the PLA and in type I collagen in the PS; collagen type III in the PLA was greater in the group with no suprapubic cystostomy diversion before surgery. There were fewer elastic fibres in both stricture areas (PLA and PS) than in the control group.

CONCLUSIONS

Urethral stricture formation is characterized by marked changes in extracellular matrix features, with consequent changes in organ function.

Progesterone Receptors in the Developing Genital Tubercle: Implications for the Endocrine Disruptor Hypothesis as the Etiology of Hypospadias

PURPOSE

In fetal mice genital tubercles the ontogenetic expression of progesterone receptors and the effect of in utero estrogen and testosterone exposure were investigated.

MATERIALS AND METHODS

To evaluate ontogenetic progesterone receptor expression genital tubercles from untreated fetuses at gestational days 12, 14, 16 and 18, and newborn pups were prepared for real-time reverse transcriptase-polymerase chain reaction or immunohistochemistry. To evaluate estrogen and testosterone effects pregnant dams were gavaged once daily with corn oil (vehicle), ethinyl estradiol or testosterone propionate from gestational days 12 through 17. At gestational day 19 the genital tubercles of delivered fetuses were harvested for morphological examination and then pooled for real-time reverse transcriptase-polymerase chain reaction.

RESULTS

Progesterone receptor protein was first detected at gestational day 12 in the urethral plate and mesenchyma. At later stages staining intensity increased with a greater progesterone receptor signal, especially in the urethra. Progesterone receptor mRNA expression showed different increasing patterns in each sex until birth. However, no difference was noted between male and female genital tubercles in terms of the distribution and quantity of progesterone receptor expression. In utero ethinyl estradiol led to 8.2, 9.7 and 5.2-fold increases in progesterone receptor mRNA in females and in males with and without hypospadias, respectively. Testosterone propionate significantly decreased progesterone receptor mRNA levels in females and males.

CONCLUSIONS

Progesterone receptors are expressed in developing genital tubercles, suggesting a direct role of progesterone in normal genital tubercle patterning. Their increasing expression until birth also implies increasing sensitivity of the genital tubercles to the effects of estrogenic and progestogenic endocrine disruptors during fetal life. Ethinyl estradiol and testosterone propionate lead to opposing effects on progesterone receptor expression, in addition to their opposing morphological effects on the genital tubercles. These findings expand our knowledge of genital tubercle morphogenesis and provide important information for understanding the effects of endocrine disruptors.

Estrogen receptor-alpha and beta are differentially distributed, expressed and activated in the fetal genital tubercle

PURPOSE

We examined the ontogenic and sex specific expression of estrogen receptor-alpha and beta in mouse genital tubercles and assessed the effects of in utero estrogen exposure on these parameters.

MATERIALS AND METHODS

Expression of the 2 genes was detected in mouse genital tubercles from fetuses collected on gestational days 12, 14, 16 and 18, and from newborns using immunohistochemistry and quantitative polymerase chain reaction. Pregnant dams were exposed to ethinyl estradiol or corn oil as the control.

RESULTS

Estrogen receptor-alpha and beta proteins first appeared on gestational days 12 and 14, respectively. The 2 proteins were expressed in the urethral plate and mesenchyma. Staining intensity was more prominent in the mesenchyma for estrogen receptor-alpha and in the urethral plate for estrogen receptor-beta. Female genital tubercles expressed more estrogen receptor-alpha than male genital tubercles (p <0.01), while estrogen receptor-alpha expression increased gradually in the 2 sexes until birth. Estrogen receptor-beta expression did not differ between males and females, and it showed no notable variation during fetal life. Ethinyl estradiol led to a 2.1 and 3.8-fold increase in estrogen receptor-alpha expression in females and in males with hypospadias (p = 0.002 and 0.04, respectively). Estrogen receptor-beta expression did not change in response to ethinyl estradiol.

CONCLUSIONS

This study provides in vivo evidence that estrogen receptor-alpha expression in the genital tubercles of each sex increases until parturition but estrogen receptor-beta expression does not, implying genital tubercle sensitivity to estrogen increases during fetal life. Exogenous administration of estrogens results in a response of increased expression of estrogen receptor-alpha but not of estrogen receptor-beta. These differential findings for estrogen receptor-alpha and beta imply that the 2 receptors may have different roles in normal or anomalous genital tubercle development.

Urothelial sonic hedgehog signaling plays an important role in bladder smooth muscle formation

During bladder development, primitive mesenchyme differentiates into smooth muscle (SM) under the influence of urothelium. The gene(s) responsible for this process have not been elucidated. We propose that the Sonic hedgehog (Shh) signaling pathway is critical in bladder SM formation. Herein, we examine the role of the Shh-signaling pathway during SM differentiation in the embryonic mouse bladder. Genes in the Shh pathway and SM expression in mouse embryonic (E) bladders (E12.5, 13.5, and 14.5) were examined by immunohistochemistry (IHC), in situ hybridization, and reverse transcription polymerase chain reaction (RT-PCR). To examine the effects of disrupting Shh signaling, bladder tissues were isolated at E12.5 and E14.5, that is, before and after bladder SM induction. The embryonic bladders were cultured on membranes floating on medium with and without 10 muM of cyclopamine, an Shh inhibitor. After 3 days, SM expression was examined by assessing the following: SM alpha-actin (SMAA), SM gamma-actin (SMGA), SM-myosin heavy chain (SM-MHC), Patched, GLI1, bone morphogenic protein 4 (BMP4), and proliferating cell nuclear antigen (PCNA) by IHC and RT-PCR. SM-related genes and proteins were not expressed in E12.5 mouse embryonic bladder before SM differentiation, but were expressed by E13.5 when SM differentiation was initiated. Shh was expressed in the urothelium in E12.5 bladders. Shh-related gene expression at E12.5 was significantly higher than at E14.5. In cyclopamine-exposed cultures of E12.5 tissue, SMAA, SMGA, GLI1, and BMP4 gene expression was significantly decreased compared with controls, but PCNA gene expression did not change. In cyclopamine-exposed E14.5 cultures, SMGA and SM-MHC gene expression did not change compared with controls. Using an in vitro embryonic bladder culture model, we were able to define the kinetics of SM- and Shh-related gene expression. Cyclopamine inhibited detrusor SM actin induction, but did not inhibit SM-MHC induction. SMAA and SMGA genes appear to be induced by Shh-signaling pathways, but the SM-MHC gene is not. Based on Shh expression by urothelium and the effects of Shh inhibition on bladder SM induction, we hypothesize that urothelial-derived Shh orchestrates induction of SM in the fetal mouse bladder.

Up-Regulation of Estrogen Responsive Genes in Hypospadias: Microarray Analysis

PURPOSE

An unexplained increase in the incidence of hypospadias has been reported, and yet to our knowledge the molecular events and their regulation leading to hypospadias remain unknown, although environmental compounds capable of endocrine activity are suspected. We screened on a global scale abnormalities in gene expression in human hypospadiac tissue compared to those in nonhypospadiac tissue. Additionally, microarray analysis of tissue from a pair of fraternal twins, including 1 with and 1 without hypospadias, served as a control for genetic variability. We hypothesized that gene expression would differ between hypospadiac vs nonhypospadiac tissue and fraternal twin data would show patterns similar to those of group data on hypospadiac and nonhypospadiac tissue.

MATERIALS AND METHODS

Microarray analysis was performed on tissue from patients with and without hypospadias, and from a pair of fraternal twins, including 1 with and 1 without hypospadias. Analysis incorporated the expression of 22,000 genes.

RESULTS

We found significant differences in gene expression, specifically with a group of genes, including CYR61, CTGF, ATF3 and GADD45beta, known to be responsive to estrogen or to interact with estrogen receptor.

CONCLUSIONS

Our findings provide support for the hypothesis that endocrine active environmental compounds may contribute to the development of hypospadias. Additionally, regulation of these genes may have a role in formation of the urethra.

Candidate genes and their response to environmental agents in the etiology of hypospadias

The molecular events that lead to isolated hypospadias remain largely unknown, and the etiology of this common congenital anomaly seems to be multifactorial. We have explored the response of several candidate genes to environmental agents that cause hypospadias in a mouse model. Here, we provide an overview of current findings in relation to candidate genes and their response to environmental agents, including the results of genomic analyses of both mouse and human tissues. In addition to steroid-hormone receptors, one gene of specific interest is activating transcription factor 3 (ATF3). We hypothesize a potential mechanism of action for ATF3 and other identified genes, including TGF-B.

Essential role for Co-chaperone Fkbp52 but not Fkbp51 in androgen receptor-mediated signaling and physiology

Fkbp52 and Fkbp51 are tetratricopeptide repeat proteins found in steroid receptor complexes, and Fkbp51 is an androgen receptor (AR) target gene. Although in vitro studies suggest that Fkbp52 and Fkbp51 regulate hormone binding and/or subcellular trafficking of receptors, the roles of Fkbp52 and Fkbp51 in vivo have not been extensively investigated. Here, we evaluate their physiological roles in Fkbp52-deficient and Fkbp51-deficient mice. Fkbp52-deficient males developed defects in select reproductive organs (e.g. penile hypospadias and prostate dysgenesis but normal testis), pointing to a role for Fkbp52 in AR-mediated signaling and function. Surprisingly, ablation of Fkbp52 did not affect AR hormone binding or nuclear translocation in vivo and in vitro. Molecular studies in mouse embryonic fibroblast cells uncovered that Fkbp52 is critical to AR transcriptional activity. Interestingly, Fkbp51 expression was down-regulated in Fkbp52-deficient males but only in affected tissues, providing further evidence of tissue-specific loss of AR activity and suggesting that Fkbp51 is an AR target gene essential to penile and prostate development. However, Fkbp51-deficient mice were normal, showing no defects in AR-mediated reproductive function. Our work demonstrates that Fkbp52 but not Fkbp51 is essential to AR-mediated signaling and provides evidence for an unprecedented Fkbp52 function, direct control of steroid receptor transcriptional activity.

Cost-Utility Analysis of Treatment Algorithms for Moderate Grade Vesicoureteral Reflux Using Markov Models

PURPOSE

The optimal treatment algorithm for vesicoureteral reflux remains controversial. Previous decision analyses have attempted to determine the best approach solely from the cost or cure perspective but have not combined the goals of minimizing treatment and disease burden. We incorporated these considerations into a contemporary, comprehensive analysis of treatment for vesicoureteral reflux.

MATERIALS AND METHODS

We examined costs from the perspective of the medical institution, and utility from the perspective of parents of children with grades II and III vesicoureteral reflux. Cost-utility analysis using Markov modeling was performed to ascertain which of 5 treatment algorithms best minimized morbidity and cost. A higher utility value was based on minimizing treatment and disease burden. Measures of treatment and disease burden included duration of suppressive antibiotics, number of invasive studies, pyelonephritis episodes, endoscopic treatments and open operations. All variables were varied spanning realistic ranges during sensitivity analyses to determine threshold values.

RESULTS

The protocol of no antibiotics or followup imaging yielded the best cost-utility for vesicoureteral reflux grades II and III. Sensitivity analysis of variables spanning realistic ranges demonstrated that utility penalties for invasive imaging and outpatient pyelonephritis were particularly important in determining the highest utility protocols, with threshold values ranging from -0.5 to -0.8.

CONCLUSIONS

In our models of treatment for vesicoureteral reflux a noninterventional approach constitutes the highest utility and least costly treatment for moderate grade reflux. Given the relative dearth of randomized trials, these analyses provide guidelines for current management of vesicoureteral reflux.