SLC20A1 Is Involved in Urinary Tract and Urorectal Development

Previous studies in developing Xenopus and zebrafish reported that the phosphate transporter slc20a1a is expressed in pronephric kidneys. The recent identification of SLC20A1 as a monoallelic candidate gene for cloacal exstrophy further suggests its involvement in the urinary tract and urorectal development. However, little is known of the functional role of SLC20A1 in urinary tract development. Here, we investigated this using morpholino oligonucleotide knockdown of the zebrafish ortholog slc20a1a. This caused kidney cysts and malformations of the cloaca. Moreover, in morphants we demonstrated dysfunctional voiding and hindgut opening defects mimicking imperforate anus in human cloacal exstrophy. Furthermore, we performed immunohistochemistry of an unaffected 6-week-old human embryo and detected SLC20A1 in the urinary tract and the abdominal midline, structures implicated in the pathogenesis of cloacal exstrophy. Additionally, we resequenced SLC20A1 in 690 individuals with bladder exstrophy-epispadias complex (BEEC) including 84 individuals with cloacal exstrophy. We identified two additional monoallelic de novo variants. One was identified in a case-parent trio with classic bladder exstrophy, and one additional novel de novo variant was detected in an affected mother who transmitted this variant to her affected son. To study the potential cellular impact of SLC20A1 variants, we expressed them in HEK293 cells. Here, phosphate transport was not compromised, suggesting that it is not a disease mechanism. However, there was a tendency for lower levels of cleaved caspase-3, perhaps implicating apoptosis pathways in the disease. Our results suggest SLC20A1 is involved in urinary tract and urorectal development and implicate SLC20A1 as a disease-gene for BEEC.

Rare Variants in BNC2 Are Implicated in Autosomal-Dominant Congenital Lower Urinary-Tract Obstruction

Congenital lower urinary-tract obstruction (LUTO) is caused by anatomical blockage of the bladder outflow tract or by functional impairment of urinary voiding. About three out of 10,000 pregnancies are affected. Although several monogenic causes of functional obstruction have been defined, it is unknown whether congenital LUTO caused by anatomical blockage has a monogenic cause. Exome sequencing in a family with four affected individuals with anatomical blockage of the urethra identified a rare nonsense variant (c.2557C>T [p.Arg853^∗]) in BNC2, encoding basonuclin 2, tracking with LUTO over three generations. Re-sequencing BNC2 in 697 individuals with LUTO revealed three further independent missense variants in three unrelated families. In human and mouse embryogenesis, basonuclin 2 was detected in lower urinary-tract rudiments. In zebrafish embryos, bnc2 was expressed in the pronephric duct and cloaca, analogs of the mammalian lower urinary tract. Experimental knockdown of Bnc2 in zebrafish caused pronephric-outlet obstruction and cloacal dilatation, phenocopying human congenital LUTO. Collectively, these results support the conclusion that variants in BNC2 are strongly implicated in LUTO etiology as a result of anatomical blockage.

CNV analysis in 169 patients with bladder exstrophy-epispadias complex

Background

The bladder exstrophy-epispadias complex (BEEC) represents the severe end of the congenital uro-rectal malformation spectrum. Initial studies have implicated rare copy number variations (CNVs), including recurrent duplications of chromosomal region 22q11.21, in BEEC etiology.

Methods

To detect further CNVs, array analysis was performed in 169 BEEC patients. Prior to inclusion, 22q11.21 duplications were excluded using multiplex ligation-dependent probe amplification.

Results

Following the application of stringent filter criteria, seven rare CNVs were identified: n = 4, not present in 1307 in-house controls; n = 3, frequency of <0.002 in controls. These CNVs ranged from 1 to 6.08 Mb in size. To identify smaller CNVs, relaxed filter criteria used in the detection of previously reported BEEC associated chromosomal regions were applied. This resulted in the identification of six additional rare CNVs: n = 4, not present in 1307 in-house controls; n = 2, frequency <0.0008 in controls. These CNVs ranged from 0.03–0.08 Mb in size. For 10 of these 13 CNVs, confirmation and segregation analyses were performed (5 of maternal origin; 5 of paternal origin). Interestingly, one female with classic bladder extrophy carried a 1.18 Mb duplication of 22q11.1, a chromosomal region that is associated with cat eye syndrome.

Conclusions

A number of rare CNVs were identified in BEEC patients, and these represent candidates for further evaluation. Rare inherited CNVs may constitute modifiers of, or contributors to, multifactorial BEEC phenotypes.

Genome-wide association study and mouse expression data identify a highly conserved 32 kb intergenic region between WNT3 and WNT9b as possible susceptibility locus for isolated classic exstrophy of the bladder

Bladder exstrophy-epispadias complex (BEEC), the severe end of the urorectal malformation spectrum, has a profound impact on continence as well as sexual and renal functions. It is widely accepted that for the majority of cases the genetic basis appears to be multifactorial. Here, we report the first study which utilizes genome-wide association methods to analyze a cohort comprising patients presenting the most common BEEC form, classic bladder exstrophy (CBE), to identify common variation associated with risk for isolated CBE. We employed discovery and follow-up samples comprising 218 cases/865 controls and 78 trios in total, all of European descent. Our discovery sample identified a marker near SALL1, showing genome-wide significant association with CBE. However, analyses performed on follow-up samples did not add further support to these findings. We were also able to identify an association with CBE across our study samples (discovery: P = 8.88 × 10(-5); follow-up: P = 0.0025; combined: 1.09 × 10(-6)) in a highly conserved 32 kb intergenic region containing regulatory elements between WNT3 and WNT9B. Subsequent analyses in mice revealed expression for both genes in the genital region during stages relevant to the development of CBE in humans. Unfortunately, we were not able to replicate the suggestive signal for WNT3 and WNT9B in a sample that was enriched for non-CBE BEEC cases (P = 0.51). Our suggestive findings support the hypothesis that larger samples are warranted to identify association of common variation with CBE.

Seamless vascularized large-diameter tubular collagen scaffolds reinforced with polymer knittings for esophageal regenerative medicine

A clinical demand exists for alternatives to repair the esophagus in case of congenital defects, cancer, or trauma. A seamless biocompatible off-the-shelf large-diameter tubular scaffold, which is accessible for vascularization, could set the stage for regenerative medicine of the esophagus. The use of seamless scaffolds eliminates the error-prone tubularization step, which is necessary when emanating from flat scaffolds. In this study, we developed and characterized three different types of seamless tubular scaffolds, and evaluated in vivo tissue compatibility, including vascularization by omental wrapping. Scaffolds (luminal Ø ∼ 1.5 cm) were constructed using freezing, lyophilizing, and cross-linking techniques and included (1) single-layered porous collagen scaffold, (2) dual-layered (porous+dense) collagen scaffold, and (3) hybrid scaffold (collagen+incorporated polycaprolacton knitting). The latter had an ultimate tensile strength comparable to a porcine esophagus. To induce rapid vascularization, scaffolds were implanted in the omentum of sheep using a wrapping technique. After 6 weeks of biocompatibility, vascularization, calcification, and hypoxia were evaluated using immunohistochemistry. Scaffolds were biocompatible, and cellular influx and ingrowth of blood vessels were observed throughout the whole scaffold. No calcification was observed, and slight hypoxic conditions were detected only in the direct vicinity of the polymer knitting. It is concluded that seamless large-diameter tubular collagen-based scaffolds can be constructed and vascularized in vivo. Such scaffolds provide novel tools for esophageal reconstruction.

Treatment response of an outpatient training for children with enuresis in a tertiary health care setting

PURPOSE

To evaluate treatment effectiveness for children with enuresis, according to the definitions of the International Children's Continence Society (ICCS, 2006).

MATERIAL AND METHODS

Children ≥6 years of age followed a 4-month outpatient treatment consisted of a visit during which history regarding enuresis was taken, causes were explained and therapeutic tips & tricks were discussed. All children received a booklet about enuresis and were trained with an alarm and/or pharmacological therapy. At baseline, 4, 10 and 16 months, the number of wet nights during the previous 28 days and the use of medication were assessed. Success of treatment was determined using ICCS definitions of treatment outcome.

RESULTS

66 children with enuresis were included (48 boys/18 girls) in this retrospective study. Mean age: 11(± 2.6) years. 91%(n = 60) of the children had non-monosymptomatic enuresis. Results at 4 months: 46% full, 15% good, 21% partial response (n = 66). At 10 months: 55% full, 4% good, 29% partial response (n = 49). At 16 months: 53% full, 6% good, 25% partial response (n = 34). Overall, use of pharmacological therapy showed a decline in time.

CONCLUSION

According to the ICCS definitions, outpatient treatment for enuresis shows a good overall treatment response, and these results can be used to compare with other studies in the future.

Needs of children with a chronic bladder in preparation for transfer to adult care

OBJECTIVE

Transfers to adult care can be problematic, resulting in postponement due to the protective nature of pediatric care and patient dependency. It is unknown whether these findings apply specifically to urology patients. Our department is taking part in a national general transition project. In this light, our aim was to investigate the specific needs of adolescent urologic patients, regarding their independence and transition.

PATIENTS AND METHODS

80 patients, born in 1975-1998, with a chronic bladder condition received a questionnaire. They were divided into pre- and post-transfer groups. Parents (n = 7) of post-transfer patients formed a third group. Questionnaires were based on those used in the national transition study, supplemented with urological questions. Pre-transfer patients were asked about their level of independence, what subjects were discussed during consultations, and their expectations and wishes regarding transfer. Post-transfer patients and parents were asked for their opinions on the transfer process.

RESULTS

73% (n = 58) responded (55 pre-transfer and 3 post-transfer patients plus parents). It appeared that the confidence built-up with the pediatric urologist impeded the transfer. An adequate level of disease-related knowledge was reported. Relationships, sexuality and fertility were hardly talked about (respectively n = 17, 16 and 18). Parents played an important role, which patients appreciated, confirming their dependency. Despite the 49% (n = 27) who stated they can arrange their urological care themselves, 44% (n = 24) felt ill-prepared for transfer.

CONCLUSION

Although overall self-perceived knowledge is sufficient, the trust in and personal relationship with the pediatric urologist formed the greatest obstruction to successful transition. These findings have been used to improve support during transition by creating a transition protocol.

Aetiology of hypospadias: a systematic review of genes and environment

BACKGROUND

Hypospadias is a common congenital malformation of the male external genitalia. Most cases have an unknown aetiology, which is probably a mix of monogenic and multifactorial forms, implicating both genes and environmental factors. This review summarizes current knowledge about the aetiology of hypospadias.

METHODS

Pubmed was used to identify studies on hypospadias aetiology published between January 1995 and February 2011. Reference lists of the selected manuscripts were also searched to identify additional studies, including those published before 1995.

RESULTS

The search provided 922 articles and 169 articles were selected for this review. Studies screening groups of patients with hypospadias for single gene defects found mutations in WT1, SF1, BMP4, BMP7, HOXA4, HOXB6, FGF8, FGFR2, AR, HSD3B2, SRD5A2, ATF3, MAMLD1, MID1 and BNC2. However, most investigators are convinced that single mutations do not cause the majority of isolated hypospadias cases. Indeed, associations were found with polymorphisms in FGF8, FGFR2, AR, HSD17B3, SRD5A2, ESR1, ESR2, ATF3, MAMLD1, DGKK, MID1, CYP1A1, GSTM1 and GSTT1. In addition, gene expression studies indentified CTGF, CYR61 and EGF as candidate genes. Environmental factors consistently implicated in hypospadias are low birthweight, maternal hypertension and pre-eclampsia, suggesting that placental insufficiency may play an important role in hypospadias aetiology. Exogenous endocrine-disrupting chemicals have the potential to induce hypospadias but it is unclear whether human exposure is high enough to exert this effect. Other environmental factors have also been associated with hypospadias but, for most, the results are inconsistent.

CONCLUSIONS

Although a number of contributors to the aetiology of hypospadias have been identified, the majority of risk factors remain unknown.

Risk factors for undescended testis

OBJECTIVE

To contribute to the understanding of the etiology of undescended testis (UDT), by exploring a wide range of potential risk factors in a case-referent study.

PATIENTS AND METHODS

Cases and referents were recruited at five hospitals and included 200 boys with surgically corrected UDT and 629 boys with persistent middle ear effusion. Risk factor data were obtained by postal questionnaires to both parents. Clinical data were collected from medical files. Adjusted odds ratios (OR) with 95% confidence intervals (CI) were estimated using logistic regression.

RESULTS

The main findings include associations between UDT and familial occurrence of the disorder: OR 3.1 (95%CI 1.9-4.9), low birth weight: 2.2 (1.1-4.3), twinning: 2.2 (0.9-5.4), gestational preeclampsia: 1.9 (0.8-4.4), use of oral contraceptives after conception: 3.6 (1.0-12.5), in vitro fertilization/intracytoplasmic sperm injection treatment: 2.2 (0.8-6.0), paternal subfertility: 1.8 (0.8-4.1), and maternal occupational exposure to cosmetics: 3.0 (0.9-10.0). Subgroup analyses indicated differences in ORs for several factors between cases with (n = 92) and without (n = 103) inguinal hernia or hydrocele.

CONCLUSION

The findings point towards a role for genetic predisposition, placental insufficiency, and possibly exposure to specific endocrine disrupting substances in the etiology of UDT. Further research should take into account potential etiologic differences between subgroups of cases with UDT.

Urotherapy in children: quantitative measurements of daytime urinary incontinence before and after treatment according to the new definitions of the International Children's Continence Society

OBJECTIVE

To assess the effectiveness of urotherapy in children with lower urinary tract dysfunction, according to the new definitions of the International Children's Continence Society.

MATERIAL AND METHODS

We performed a retrospective review of 122 children (aged 8.8 ± 2.0 years) treated in an outpatient program for lower urinary tract dysfunction. Exclusion criteria included all neurologic abnormalities. In 98 children (80%) daytime urinary incontinence was a predominant symptom. Therapy consisted of an individually adapted drinking and voiding schedule, pelvic floor relaxation, instructions on toilet behavior, biofeedback uroflowmetry and if necessary recommendations for regulation of defecation. Before and at the end of training, patients were evaluated for number and severity of daytime wet accidents per week, using a scoring system to grade the severity of incontinence. Secondary measurements of accompanying voiding symptoms were performed.

RESULTS

Of the 90 children with daytime urinary incontinence for whom sufficient objective data were collected, 42% became completely dry during the daytime and 36% showed a 50% or greater level of response. Secondary measurements showed a significant reduction in daily voiding frequency (mean 7.0 ± .3, P<0.0001) and mean post-void residual (P<0.003), and an improvement in flow pattern (P<0.05).

CONCLUSIONS

Urotherapy is successful for the treatment of daytime urinary incontinence in children. Additional benefit was evident in improvement of accompanying voiding symptoms. A combination of the definitions of the International Children's Continence Society and a scoring system to grade severity improved the evaluation method. Further research into long-term efficacy will be performed.

[The undescended testis: arguments in favour of early treatment, provided retractile testis and acquired non-scrotal testis have been excluded]

--Guidelines for the treatment ofundescended testis (UDT) are sparse. Often an operation in the second year of life is advised. --Recent data indicate that the normal maturation process, which will ultimately lead to a normal quantity and quality of germ cells, is impaired as early as in the first half year of a newborn's life. None of the guidelines take this into account. Spontaneous descent after the fourth month following birth, of testes that have previously not descended, hardly ever occurs. --No differences have been shown in complication numbers between surgery before and after the first birthday. Orchidopexy prior to the 13th birthday reduces the risk of testicular cancer. --Therefore, based on these data, it is advised to perform orchidopexy in the second half of the first year of a newborn's life. In older boys a UDT must be treated before the 13th birthday. --In the Netherlands a lot more orchidopexies are done despite what may be expected based on prevalence numbers of UDT: testes retaining a normal volume that would most probably have descended spontaneously come puberty. --It remains important to carry out a careful physical examination and document the position of the testes soon after birth, and later on if UDT is suspected, to avoid unnecessary operations on retractile testes and acquired UDT.

Delayed intrauterine repair of an experimental spina bifida with a collagen biomatrix

BACKGROUND/PURPOSE

The aim of the study was to evaluate whether a collagen biomatrix is useful for delayed intrauterine coverage of a surgically created spina bifida in a fetal lamb.

METHODS

In 20 fetal lambs, surgery was performed at 72 or 79 days' gestation. In 15 lambs a spina bifida was created surgically. In 8 lambs it was covered with a collagen biomatrix 2 weeks later and in 7 lambs it was left uncovered. Five lambs served as sham operated controls. Neurological examination was performed at 1 week of age and afterwards the lambs were sacrificed for further histological evaluation.

RESULTS

None of the 5 surviving lambs with the defect covered showed loss of spinal function and the architecture of the spinal cord was preserved in 4 of the 5 lambs. In the uncovered group, 1 of the 4 surviving lambs had loss of spinal function, 5 lambs were available for histological evaluation and 4 of them showed disturbance of the architecture of the spinal cord.

CONCLUSIONS

Collagen biomatrices can be used for intrauterine coverage of an experimental spina bifida and can preserve the architecture of the spinal cord. Neurological outcome is not different between fetuses with their spinal cord covered and fetuses with uncovered cords.

Risk factors for hypospadias

Despite being one of the most common congenital defects in boys, the etiology of hypospadias remains largely unknown. In this case-referent study, we evaluated a wide spectrum of potential risk factors for hypospadias. Cases were identified from the hospital information system, and referents were recruited through the parents of the cases. Both parents of cases and referents completed written questionnaires that they received through the mail. Logistic regression analyses were used to assess the independent contribution of different factors to the risk of hypospadias. The final database included 583 cases and 251 referents. Hypospadias more often occurred in children whose father had hypospadias (OR=9.7; 95%CI: 1.3-74.0) and in children with a low birth weight (OR=2.3; 95%CI: 1.2-4.2). Indications for elevated risks were found when mothers were DES-daughters (OR=3.5; 95%CI: 0.8-15.6), fathers were subfertile (OR=1.8; 95%CI: 0.7-4.5), the parents had undergone fertility treatment (OR=2.3; 95%CI: 0.9-5.8), and in twin or triplet pregnancies (OR=2.0; 95%CI: 0.8-5.1). Maternal use of iron supplements (OR=2.2; 95%CI: 0.8-6.0), maternal smoking (OR=1.5; 95%CI: 1.0-2.4), paternal prescriptive drug use (OR=2.6; 95%CI: 1.1-6.6), and paternal exposure to pesticides (OR=2.1; 95%CI: 0.6-7.1) during the 3 months immediately prior to conception or in the first trimester of pregnancy also appeared to increase the risk of hypospadias. The associations found in this study support the hypothesis that genetic predisposition, placental insufficiency, and substances that interfere with natural hormones play a role in the etiology of hypospadias.

Bladder exstrophy and male fertility: pregnancies after ICSI with ejaculated or epididymal sperm

OBJECTIVE

To define the additional value of intracytoplasmatic sperm injection (ICSI).

DESIGN

Descriptive clinical study.

SETTING

Male patients with bladder exstrophy in an academic setting.

PATIENT(S)

Three male patients in a stable relationship, desirous to have their own children. They were born with bladder exstrophy and had undergone surgical reconstruction.

INTERVENTION(S)

The ICSI procedure.

MAIN OUTCOME MEASURE(S)

Number of pregnancies.

RESULT(S)

Each of the three men presented a different way of producing sperm. The first male patient had no ejaculation, and sperm cells were retrieved by percutaneous sperm aspiration (PESA). The second could ejaculate with the production of sperm cells, and the third had no ejaculation but collected prostatic fluid by catheterization of a cutaneous fistula; this fluid contained sperm cells. Their partners all had undergone a successful ICSI procedure.

CONCLUSION(S)

Nowadays, men with bladder exstrophy reach adult age and therefore express the desire to parent their own children. Careful attention to genital reconstruction has to be given to enhance the possibility to antegrade production of sperm. In cases when this is not possible, PESA/testicular sperm extraction in combination with ICSI offer an added opportunity for these couples.

Dysfunction of lower urinary tract in renal transplant children with nephrologic disease

OBJECTIVES

To investigate the relationship between dysfunction of the lower urinary tract after renal transplantation and renal transplant function in children with an underlying nephrologic disease.

METHODS

The research group consisted of 21 renal transplant children (12 girls and 9 boys, mean age 13.5 years, range 6 to 18) with an underlying nephrologic disease. To indicate renal transplant function, the calculated creatinine clearance rate (Ccr) according to Schwartz was used. The Ccr was measured at two points, 2 months after transplantation and at the moment of study. The average graft age was 34 months (range 5 to 85). The data on dysfunction of the lower urinary tract were gathered using a written questionnaire, frequency volume chart, free uroflowmetry, transabdominal ultrasonography, and medical records. To determine the relationship between the symptoms of dysfunction of the lower urinary tract and Ccr at the moment of study, we computed bivariate correlations and performed multivariate regression analyses in which the associations were studied while controlling for the Ccr 2 months after transplantation and graft age.

RESULTS

A sensation of incomplete emptying (P = 0.03), postvoid residual urine volume (P = 0.06), and urinary tract infection (P = 0.004) correlated negatively with the Ccr at the moment of study. These effects remained present (P = 0.07, P = 0.03, and P = 0.003, respectively) while controlling for graft age and the Ccr at 2 months after transplantation in the regression analysis.

CONCLUSIONS

The results of our study have shown that a postvoid residual urine volume and urinary tract infections after renal transplantation may result in renal transplant deterioration in children with an underlying nephrologic disease.

Histological Evaluation of Acute Covering of an Experimental Neural Tube Defect with Biomatrices in Fetal Sheep

OBJECTIVE

The aim of the study was to determine the histological effect on the neural tissue of in utero covering of an experimental neural tube defect in fetal lambs, with the use of two different biomatrices.

MATERIALS AND METHODS

In 23 fetal sheep, surgery was performed at 79 days' gestation. In 19 of these, a neural tube defect was created, while 4 fetuses served as sham-operated controls. In 7 of the 19 operated fetuses the defect was left uncovered. In the remaining 12 animals the defect was covered either with a collagen biomatrix (4 animals), skin (3 animals), or small intestinal submucosa biomatrix (5 animals). The lambs were sacrificed at 1 week of age and histological examination was performed.

RESULTS

All lambs with an uncovered neural tube defect showed histological damage of the spinal cord. In lambs in which the neural tube defect was covered, one half showed a normal architecture of the spinal cord while minor histological damage was present in the other half. Between the three groups in which the defect was covered, the histological outcome was comparable.

CONCLUSIONS

Acute covering of an experimental neural tube defect in fetal lambs prevents severe histological damage to the spinal cord independent of the two biomatrices used in this study.

Lower Urinary Tract Symptoms After Renal Transplantation in Children

PURPOSE

We investigated the prevalence and nature of LUTS after renal Tx in children. The focus of the study was the presence of LUTS in children without a history of urological symptoms. We also studied the relationship between the characteristics of these patients and the occurrence of LUTS.

MATERIALS AND METHODS

Data were gathered using a written questionnaire, frequency volume chart, free uroflowmetry, transabdominal ultrasonography and medical records. The study group (30 patients) consisted of 9 children (30%) undergoing renal transplantation with an underlying urological disease and 21 (70%) with an underlying nephrological disease.

RESULTS

In the nephrological group the incidence of high capacity bladder was 75%, residual urine 50%, UTI 43%, hesitancy 38%, intermittent flow 33%, bladder pain 33%, nighttime incontinence 29%, nocturia 24%, feeling of incomplete emptying 15%, daytime incontinence 14%, straining 14%, urgency 10%, burning sensation 10% and intermittency 5%. No substantial difference in the occurrence of LUTS, UTI or high bladder capacity after Tx was found between children with an underlying urological disease and those with an underlying nephrological disease. On average, patients in both groups suffered from 3 different LUTS.

CONCLUSIONS

After renal Tx children with a nephrological disease demonstrated a high incidence of LUTS. The occurrence of LUTS combined with UTI and increased bladder capacity indicates that these children are at risk for development of myogenic failure. This finding emphasizes the importance of close urological followup after Tx in children with urological and nephrological disease.

Hypospadias: a transgenerational effect of diethylstilbestrol?

BACKGROUND

In 2002, an increased risk of hypospadias was reported for sons of women exposed to diethylstilbestrol (DES) in utero, suggesting transgenerational effects of DES. The aim of this study was to further assess the association between parental DES exposure and hypospadias in a case-referent study.

METHODS

Cases with hypospadias were retrieved from the hospital information system. Referents were recruited via the parents of cases. Both parents completed postal questionnaires. Associations were estimated by odds ratios (OR) with 95% confidence intervals (CI). Additionally, conditional logistic regression analyses were performed for a matched subset of parents.

RESULTS

The final database included 583 cases and 251 referents. In the initial analyses, an indication was found for an increased risk of hypospadias when mothers were exposed to DES in utero: OR=2.3 (95% CI 0.7-7.9). Conditional logistic regression resulted in a stronger risk estimate: OR=4.9 (95% CI 1.1-22.3). Paternal exposure to DES did not increase the risk.

CONCLUSIONS

The results confirm an increased risk of hypospadias when mothers were exposed to DES in utero. However, the excess risk appears to be of much smaller magnitude than in the 2002 study. Further research on the potential health risks for the third generation is of great importance.

In utero Repair of an Experimental Neural Tube Defect in a Chronic Sheep Model Using Biomatrices

OBJECTIVE

Persistent exposure of the unprotected spinal cord to amniotic fluid and the uterine wall can lead to progressive damage of neural tissue in case of a myelomeningocele (two-hit hypothesis). The aim of this study was to evaluate whether in utero repair of an experimental neural tube defect in a fetal lamb could protect neural tissue from secondary injury and save neurologic functions after birth.

METHODS

In 19 fetal lambs, a neural tube defect was created at 79 days' gestation. In 12 lambs the defect was covered either with a novel, molecular defined collagen-based biocompatible and biodegradable matrix (UMC) or with a small intestinal submucosa (SIS) biomatrix (Cook) or by closing the skin over the defect.

RESULTS

All lambs with the defect covered showed no or minor neurologic morbidity in contrast to the lambs with the defect uncovered in which major neurologic morbidity was seen.

CONCLUSIONS

These results demonstrate that long-term exposure of the open spinal cord to the intrauterine environment can lead to damage of neural tissue and, consequently loss of neurologic functions and that coverage of the defect can lead to a better neurologic outcome. Furthermore, we could show that a UMC biomatrix and an SIS biomatrix are useful for in utero coverage of a surgically created neural tube defect in our model.

Localization and functional characterization of glycosaminoglycan domains in the normal human kidney as revealed by phage display-derived single chain antibodies

Glycosaminoglycans (GAG) play an important role in renal homeostasis. They are strongly negatively charged polysaccharides that bind and modulate a myriad of proteins, including growth factors, cytokines, and enzymes. With the aid of specific phage display-derived antibodies, the distribution of heparan sulfate (HS) and chondroitin sulfate (CS) domains in the normal human kidney was studied. HS domains were specifically located in basement membranes and/or surfaces of renal cells and displayed a characteristic distribution over the nephron. A characteristic location in specific parts of the tubular system was also observed. CS showed mainly an interstitial location. Immunoelectron microscopy indicated specific ultrastructural location of domains. Only partial overlap with any of seven different proteoglycan core proteins was observed. Two HS domains, one highly sulfated (defined by antibody HS4C3) and one low sulfated (defined by antibody RB4Ea12), were studied for their cell biologic relevance with respect to the proliferative effect of FGF-2 on human mesangial cells in vitro. Fibroblast growth factor 2 (FGF-2) binding was HS dependent. Addition of purified HS4C3 antibody but not of the RB4Ea12 antibody counteracted the binding and the proliferative effect of FGF-2, indicating that the HS4C3 domain is involved in FGF-2 handling by mesangial cells. In conclusion, specific GAG domains are differentially distributed in the normal human kidney and are likely involved in binding of effector molecules such as FGF-2. The availability of tools to identify and study relevant GAG structures allows the development of glycomimetica to halt, for instance, mesangial proliferation and matrix production as seen in diabetic nephropathy.

Renal transplant nephrectomy in children: can an aggressive approach be recommended?

BACKGROUND

A patient with a failed renal graft is generally approached conservatively, especially when graft failure occurs more than 1 month after transplantation. This approach was the cause of extensive morbidity in our institution and therefore we evaluated the correctness of our approach towards transplanted children.

PATIENTS AND METHODS

Case histories of 182 renal transplants in 145 patients, performed between 1977 and 1999 were reviewed.

RESULTS

A total of 63 renal grafts failed: 19 between 0-1 month (group 1), 22 between 1 month and 1 yr (group 2) and 22 later than 1 yr after transplantation (group 3). Fifty-three grafts (84%) were removed: 100% of group 1, 86% of group 2 and 68% of group 3. The symptoms that indicated the need for graft removal were fever without a clear infection focus (n = 12), abdominal pain in the transplant area (n = 14), macroscopic hematuria (n = 10) and severe hypertension (n = 22). After transplant nephrectomy pain, fever and macroscopic hematuria completely resolved in all and hypertension resolved in 36% of patients. Transplant nephrectomy-associated morbidity was observed in 38% of the patients with 100% recovery.

CONCLUSION

The clinical outcome confirmed the indications for transplant nephrectomy. Our future approach will be more aggressive: as soon as symptoms such as unexplained fever, local pain or macroscopic hematuria appear, graft removal will be performed without delay.

A rabbit model to tissue engineer the bladder

A rabbit model was used for the evaluation of a collagen-based biomatrix of small intestinal submucosa (SIS, COOK) in comparison to a biochemically reconstructed biomatrix for bladder tissue regeneration. Rabbits underwent partial cystectomy and cystoplasty with SIS patch graft or with a biochemically defined collagen biomatrix. The grafts of the regenerated bladder wall were harvested at different intervals and tissue regeneration was evaluated. The results of the SIS and biochemically defined biomatrix grafts were comparable. At harvesting, we found five bladder stones and encrustation of the biomatrix in 21/56 animals. No stone formation was observed in the control group. The results of the molecularly defined biomatrix are thus far comparable to SIS. Both matrices show good epithelialization and ingrowth of smooth muscle cells. Both biomatrices show considerable encrustation, which appears to disappear in time. The rabbit model is suitable for bladder tissue engineering studies as it is an easy model to use. In this model, besides tissue regeneration, also some of the clinical problems are seen such as encrustation of foreign body material in the bladder. These aspects are subject for further pre-clinical studies in this animal model.

The long term outcome of feminizing genital surgery for congenital adrenal hyperplasia: anatomical, functional and cosmetic outcomes, psychosexual development, and satisfaction in adult female patients

BACKGROUND

There are only a few reports analyzing the long term outcome of feminizing surgery in females with congenital adrenal hyperplasia (CAH). Such analysis is crucial to evaluate the treatment and to make necessary adjustments.

STUDY OBJECTIVES

To evaluate the adult outcome after feminizing surgery in adult females with salt wasting CAH.

DESIGN

Retrospective observational followup investigation.

SETTING

Outpatient clinic of a University Medical Center, in 2002.

PARTICIPANTS

Eight patients (born 1973-1983) who underwent feminizing surgery in infancy by the same procedure and the same pediatric surgeon in our center, and 19 healthy female controls (for visual analog scales).

METHODS

(a) Study of patients' records (n=8); (b) Systematic evaluation of the current situation (n=6): uroflowmetry, a written questionnaire to screen for psychopathology (Youth Adult Self Report, YASR), structured gynecologic examination and a structured psychosexual interview, including scoring on visual analog scales.

RESULTS

(a) The first surgery (age 0.1-3.7 yr) consisted of clitoris reduction and vaginoplasty (single-stage) in 7 patients and clitoris reduction only in one patient. The latter patient had vaginoplasty in puberty. In puberty, 6 of the 7 patients with an initial single-stage procedure required re-vaginoplasty. All 6 patients who participated in this systematic evaluation had undergone (re-) vaginoplasty in puberty; (b) 2 of the 6 patients experienced some urinary incontinence, and in one of them, the uroflowmetry result was abnormal. The YASR showed no psychopathology, except for 1 patient with a slightly elevated externalizing score. Gynecologic examination (n=5) revealed vaginal strictures in 3 patients (1 severe, 2 mild). The 2 patients without vaginal strictures had coitus regularly. In the interview, 2 patients called themselves bisexual, the other 4 heterosexual. None of the patients had homosexual contacts. Sexual developmental milestones (romantic interest, falling in love, kissing and petting, coitus) had been reached by all, except for 1 patient who did not have coitus yet. In the patient group, satisfaction with height, body hair, and external genitalia and sexual fantasies and interest, measured with visual analog scales, was not different compared to the control group, except for satisfaction with total body appearance, which was significantly lower in the patients.

CONCLUSION

Despite the poor outcome of the initial single-stage surgery in infancy and the inevitable re-operation in puberty, the adult outcome in our study population seems more positive than the findings in the few previous reports, especially with respect to sexual development and activity.

Anionic and cationic drug secretion in the isolated perfused rat kidney after neonatal surgical induction of ureteric obstruction

OBJECTIVE

To study the pathophysiological changes of renal tubular drug transport mechanisms in congenital renal obstruction, by developing a model for perfusing the isolated kidney (IPK) after neonatal surgical induction of partial ureteric obstruction in Hanover Wistar rats.

MATERIAL AND METHODS

Moderately severe obstruction of the right kidney of male rats was created by burying a segment of the right ureter under the psoas fascia at 5-7 days after birth. Different fluorescent substrates for renal organic anion and cation drug transport systems were added to the IPK, and the concentration of these substances with time analysed in perfusate and urine.

RESULTS

The reproducibility in all groups of the glomerular filtration rate (GFR) and drug excretion was remarkably good. GFR was significantly lower in obstructed kidneys than in unobstructed kidneys. 123Rhodamine, a marker for organic cation and P-glycoprotein transport, had a significantly lower maximum excretion rate in the obstructed than in unobstructed kidneys. Renal fractional clearance (123rhodamine clearance corrected for diminished GFR) was also significantly lower in obstructed kidneys. There was no significant difference in maximum excretion (absolute and corrected GFR) for Lucifer Yellow, a marker for sodium-dependent organic anion transport. The maximum excretion rate of calcein, a marker for sodium-independent organic anion transport, was significantly lower in the obstructed than in the unobstructed kidneys, but significantly higher after correcting for reduced GFR.

CONCLUSION

The IPK is a good model for studying the effect of neonatal renal obstruction on tubular drug transport. These results show that organic anion and cation transport mechanisms are affected differently by obstruction.

Rabbit urethra replacement with a defined biomatrix or small intestinal submucosa

OBJECTIVE

The evaluation of collagen-based biomatrix (SIS COOK((R))) in comparison to a biochemically reconstructed biomatrix for replacement of the urethra in a rabbit model as a preclinical model.

MATERIAL AND METHODS

Rabbits underwent partial urethra replacement (resection of 0.5 to 1.0 cm segment of the urethra), which was replaced with 1 or 4 layers Small Intestinal Submucosa (SIS COOK) patch grafts or with a biochemically defined collagen biomatrix, partly sutured with unresolvable sutures for future reference. Six animals underwent a sham control operation. The grafts of regenerated urethras were harvested at 1, 3 and 9 months after implantation. Urethrography was performed pre-operatively and before sacrificing. The animals were evaluated macroscopically and by routine histology and immunohistochemistry.

RESULTS

At 1 month after implantation, the biomatrices (1 layer, 4 layers and our biochemically defined biomatrix) were well distinguishable from the normal surrounding tissues and showed blood vessels at the periphery. Macroscopically, the unresolvable reference sutures were easy to find at all time points. At 3 months the graft was still distinguishable in the 4 layers SIS group. In the 1 layer and the defined biomatrix group a good regeneration of the urethra within the graft was seen with some central fibrosis. Histological and immunohistochemical evaluation showed urothelium regeneration on the 1 layer and on biochemically defined biomatrix with decreasing number of inflammatory cells from 1 month on. In the group treated with 4 layers SIS the urothelium was completely regenerated at 3 months. Histologically, the regeneration of muscle cells in the three biomatrices was comparable. The smooth muscle cells regenerated very slowly as 1 month after implantation no muscle cells were detectable within the grafts. At 3 months a few muscle cells were present in the graft, but cell density did not increase in the following 6 months. Strictures were not observed on control urethrography pre-operatively in the animals. In one case slight narrowing of the urethra on urethrography was seen, but apparently without causing voiding problems. One rabbit developed a fistula near the operation site.

CONCLUSION

The biomatrices investigated are feasible scaffolds to repair urethral lesions. The results with our biochemically defined biomatrix are comparable to one layer Small Intestinal Submucosa. Almost no smooth muscle cells population was observed after nine months for the three biomatrices. We conclude that an improved molecularly defined biomatrix focussed on stimulation of smooth muscle cell growth may be necessary to obtain optimal cellular grafting results.

Surgical instrument migration from the abdominal cavity through the bladder into the vagina: a rare long-term complication

A foreign body in the bladder is a well-recognized, although rare, cause of urinary tract infections. We describe a 15-year-old girl who presented with abdominal pain and recurrent urinary tract infections. On analysis, a forceps was found, with the two legs of the instrument separately perforating both the back wall of the bladder and the trigone, with the top of the forceps lying in the vagina, covered with a large calculus. The forceps must have been left behind during laparotomy for bowel invagination in her first year of life.

Perinatal rupture of the uropoietic system

AIMS

Ruptures of the uropoietic system resulting in either urinary ascites or urinoma are rare complications in the neonate. Although ruptures without clear predisposing factors are described, in most cases they are associated with obstructive uropathy. The diagnosis is often delayed and the prognosis is related to the degree of renal damage. There is discussion about possible protective mechanisms of the rupture for renal function in patients with obstructive uropathy.

METHODS

We retrospectively analyzed the clinical presentation, predisposing factors and the renal function before and after treatment of 10 neonates with a rupture of the pyelum or urinary bladder in our hospital.

RESULTS

The group consisted of 9 boys and 1 girl. The average birth weight was 3,880 g. The patients presented with distended abdomen (n = 10), abdominal mass (n = 2), ascites (n = 5), oligohydramnion (n = 2), hypertension (n = 1) and anuria (n = 1). Underlying diagnosis included obstruction of the ureteropelvic junction (UPJ obstruction) in 3 children and posterior urethral valves in 7 children. Five children presented with urinoma, 3 children had a urinoma in combination with ascites and 2 children had isolated ascites. All children had reduced renal function at the time of diagnosis. In all 10 cases, the serum creatinine decreased after treatment. Scintigraphic investigation with mercapto-acetyltriglycerine (MAG III) demonstrated diminished function and perfusion of all 3 kidneys with UPJ obstruction and isolated urinoma even after treatment. Children with posterior urethral valves and urinoma revealed better function of the ruptured kidney and diminished function of the kidney which was not ruptured. One child with a rupture of the urinary bladder and urinary ascites showed good function and perfusion of both kidneys.

CONCLUSION

Perinatal ruptures of the uropoietic system are rare. The clinical presentation is aspecific. One should consider a rupture of the urinary bladder or pyelum in a neonate with a distended abdomen, hydronephrosis and ascites. The long-term prognosis depends on the underlying diagnosis and the location of the rupture. Probably, a UPJ obstruction with an isolated urinoma is associated with irreversible renal damage of the ruptured kidney. A rupture resulting in urinary ascites apparently provides better decompression with better function of the ruptured kidney. Scintigraphic investigation is necessary for a separate evaluation of the single kidney function.