A Predictive Model to Identify the Effects of Transcutaneous Sacral Nerve Stimulation With Pelvic Floor Exercises in Fecal Incontinence After Surgery for Anorectal Malformation.

INTRODUCTION: Although the combination of transcutaneous sacral nerve stimulation (tSNS) and pelvic floor exercises (PFEs) has shown significant effectiveness in treating fecal incontinence (FI) after surgery for congenital anorectal malformation (CARM), not all patients achieve satisfactory continence. Therefore, identifying which individuals will benefit from this method is crucial. METHODS: A prospective cohort study enrolled 92 children with FI. All patients underwent tSNS with PFE treatment, and an improved outcome was defined as a Wexner score ≤4. A predictive model to identify the effects of tSNS with PFEs in FI was developed based on the analysis of magnetic resonance imaging and high-resolution anorectal manometry with area under the receiver-operating characteristic curve to evaluate the predictive value of external anal sphincter (EAS) thickness index and anal squeezing pressure (ASP). RESULTS: tSNS with PFEs improved outcomes in 72 patients and led to poor outcomes in 20 (4 had their rectums deviate from the puborectalis muscle center or puborectal muscle ruptures while 16 lacked EAS with a lower ASP). The areas under the receiver-operating characteristic curve for EAS thickness index and ASP in predicting the effects of tSNS with PFEs were 0.915 (95% confidence interval 0.846-0.983, P = 0.000) and 0.886 (95% confidence interval 0.819-0.952, P = 0.000), respectively. By applying cutoff values of 0.076 for EAS thickness index and 21.95 mm Hg for ASP, tSNS with PFEs was found to be ineffective. DISCUSSION: tSNS with PFEs is effective for most patients with FI after CARM surgery, except when the rectum deviates from the puborectal muscle center, puborectal muscle rupture occurs, or EAS is absent with a low ASP.

A novel c.64G > T (p.G22C) NR5A1 variant in a Chinese adolescent with 46,XY disorders of sex development: a case report.

BACKGROUND: Adolescents with 46,XY disorders of sex development (DSD) face additional medical and psychological challenges. To optimize management and minimize hazards, correct and early clinical and molecular diagnosis is necessary. CASE PRESENTATION: We report a 13-year-old Chinese adolescent with absent Müllerian derivatives and suspected testis in the inguinal area. History, examinations, and assistant examinations were available for clinical diagnosis of 46,XY DSD. The subsequent targeting specific disease-causing genes, comprising 360 endocrine disease-causing genes, was employed for molecular diagnosis. A novel variation in nuclear receptor subfamily 5 group A member 1 (NR5A1) [c.64G > T (p.G22C)] was identified in the patient. In vitro functional analyses of the novel variant suggested no impairment to NR5A1 mRNA or protein expression relative to wild-type, and immunofluorescence confirmed similar localization of NR5A1 mutant to the cell nucleus. However, we observed decreased DNA-binding affinity by the NR5A1 variant, while dual-luciferase reporter assays showed that the mutant effectively downregulated the transactivation capacity of anti-Müllerian hormone. We described a novel NR5A1 variant and demonstrated its adverse effects on the functional integrity of the NR5A1 protein resulting in serious impairment of its modulation of gonadal development. CONCLUSIONS: This study adds one novel NR5A1 variant to the pool of pathogenic variants and enriches the adolescents of information available about the mutation spectrum of this gene in Chinese population.

A novel inhibitor of ARfl and ARv7 induces protein degradation to overcome enzalutamide resistance in advanced prostate cancer.

Enzalutamide (ENZ) is a second-generation androgen receptor (AR) antagonist used for the treatment of castration-resistant prostate cancer (CRPC) and reportedly prolongs survival time within a year of starting therapy. However, CRPC patients can develop ENZ resistance (ENZR), mainly driven by abnormal reactivation of AR signaling, involving increased expression of the full-length AR (ARfl) or dominantly active androgen receptor splice variant 7 (ARv7) and ARfl/ARv7 heterodimers. There is currently no efficient treatment for ENZR in CRPC. Herein, a small molecule LLU-206 was rationally designed based on the ENZ structure and exhibited potent inhibition of both ARfl and constitutively active ARv7 to inhibit PCa proliferation and suppress ENZR in CRPC. Mechanically, LLU-206 promoted ARfl/ARv7 protein degradation and decreased ARfl/ARv7 heterodimers through mouse double minute 2-mediated ubiquitination. Finally, LLU-206 exhibited favorable pharmacokinetic properties with poor permeability across the blood-brain barrier, leading to a lower prevalence of adverse effects, including seizure and neurotoxicity, than ENZ-based therapies. In a nutshell, our findings demonstrated that LLU-206 could effectively inhibit ARfl/ARv7-driven CRPC by dual-targeting of ARfl/ARv7 heterodimers and protein degradation, providing new insights for the design of new-generation AR inhibitors to overcome ARfl/ARv7-driven CRPC.

Hepatic interferon regulatory factor 8 expression suppresses hepatocellular carcinoma progression and enhances the response to anti-programmed cell death protein-1 therapy.

BACKGROUND AND AIMS: Therapeutic blockade of the programmed cell death protein-1 (PD-1) immune checkpoint pathways has resulted in significant reactivation of T cell-mediated antitumor immunity and is a promising clinical anticancer treatment modality in several tumor types, but the durable response rate remains relatively low (15%-20%) in most patients with HCC for unknown reasons. Evidence reveals that the interferon signaling pathway plays a critical role in modulating the efficacy and sensitivity of anti-PD-1 therapy against multiple tumor types, but the mechanisms are unclear. APPROACH AND RESULTS: Using Kaplan-Meier survival analysis based on HCC databases, we found that deceased expression of interferon regulatory factor (IRF) 8 in HCC, among all the nine IRF members that regulate interferon signals, was associated with poor prognosis of patients with HCC. Moreover, gene set enrichment analysis identified the interferon-gamma and PD-1 signaling signatures as the top suppressed pathways in patients with IRF8-low HCC. Contrarily, overexpression of IRF8 in HCC cells significantly enhanced antitumor effects in immune-competent mice, modulating infiltration of tumor-associated macrophages (TAMs) and T cell exhaustion in tumor microenvironment. We further demonstrated that IRF8 regulated recruitment of TAMs by inhibiting the expression of chemokine (C-C motif) ligand 20 (CCL20). Mechanically, IRF8-mediated repression of c-fos transcription resulted in decreased expression of CCL20, rather than directly bound to CCL20 promoter region. Importantly, adeno-associated virus 8-mediated hepatic IRF8 rescue significantly suppressed HCC progression and enhanced the response to anti-PD-1 therapy. CONCLUSIONS: This work identified IRF8 as an important prognostic biomarker in patients with HCC that predicted the response and sensitivity to anti-PD-1 therapy and uncovered it as a therapeutic target for enhancing the efficacy of immune therapy.

Congenital perineal hamartomas with rectal duplication: A case report.

Background: Congenital perineal hamartomas are rare, and reports of prenatal ultrasound diagnosis are limited. Perineal hamartomas are usually associated with other structural malformations, which complicate the therapeutic regime. Case presentation: We report a case of perineal hamartomas associated with rectal duplication in a female fetus. A review of the literature on similar cases was also presented. A fetus was first diagnosed with a perineal mass at 33 weeks of gestation using ultrasound examination in our hospital. Two-dimensional ultrasonography showed a hyperechoic mass resembling a scrotum in the perineum of the fetus. The pedicle connected the mass to the fetal anus. The masses were excised after birth, and perineal hamartomas were confirmed by pathological diagnosis. Rectal duplication, an associated malformation, was found during the surgery. The rectal duplication cyst was removed at the same time. Conclusion: Congenital perineal masses are rare and are usually associated with urogenital and anorectal malformations. Prenatal ultrasound should be used to assess the position and relationship between the mass and perineal organs, and to exclude other combined deformities.

Asymmetric distribution of CRUMBS polarity complex proteins from compacted 8-cell to blastocyst stage during mouse preimplantation development.

During mouse preimplantation development, blastomeres are equipotent until polarity establishment at compacted 8-cell stage. The intrinsic nature of polarity is the asymmetric distribution of polarity proteins between inside and outside blastomeres along the direction of apical-basal axis. This study investigated the early developmental temporal and spatial expression of the main CRUMBS polarity complex proteins in the mouse preimplantation embryo. We observed that Crb3, Pals1, Patj and Mpdz are transcribed in the mouse preimplantation embryo. However, the asymmetric distribution of these polarity proteins is not established until the compacted 8-cell stage. From compaction and thereafter, CRB3 and PALS1 are progressively enriched in the apical membrane, while PATJ and MPDZ are discretely localized at both tight junctions and the apical membrane adjacent to tight junctions. These temporal and spatial distribution patterns suggest that CRUMBS polarity complex might be involved in the cell polarity establishment in the early mouse embryo and reinforce the viewpoint that developmentally spatial asymmetries are first set up at the compaction stage. The present study provides a foundation for further investigation on the functions of CRUMBS polarity complex in trophectoderm specification and blastocyst morphogenesis.

Chromosome 13q deletion syndrome involving 13q31­qter: A case report.

Partial deletions on the long arm of chromosome 13 lead to a number of different phenotypes depending on the size and position of the deleted region. The present study investigated 2 patients with 13q terminal (13qter) deletion syndrome, which manifested as anal atresia with rectoperineal fistula, complex type congenital heart disease, esophageal hiatus hernia with gastroesophageal reflux, facial anomalies and developmental and mental retardation. Array comparative genomic hybridization identified 2 regions of deletion on chromosome 13q31­qter; 20.38 Mb in 13q31.3­qter and 12.99 Mb in 13q33.1­qter in patients 1 and 2, respectively. Comparisons between the results observed in the present study and those obtained from patients in previous studies indicate that the gene encoding ephrin B2 (EFNB2) located in the 13q33.3­q34 region, and the gene coding for endothelin receptor type B, in the 13q22.1­31.3 region, may be suitable candidate genes for the observed urogenital/anorectal anomalies. In addition, the microRNA­17­92a­1 cluster host gene and the glypican 6 gene in the 13q31.3 region, as well as EFNB2 and the collagen type IV a1 chain (COL4A1) and COL4A2 genes in the 13q33.1­q34 region may together contribute to cardiovascular disease development. It is therefore possible that these genes may be involved in the pathogenesis of complex type congenital heart disease in patients with 13q deletion syndrome.

Hedgehog gene polymorphisms are associated with the risk of Hirschsprung's disease and anorectal malformation in a Chinese population.

Hedgehog (HH) is one of the key morphogens expressed in the gut mesenchyme that control animal development and tissue homeostasis. The HH gene has been shown to be closely associated with Hirschsprung's disease (HSCR) and anorectal malformations (ARMs); thus, it was hypothesized that HH signaling pathway­associated genes may be candidate genes for HSCR and ARMs. The present study aimed to evaluate whether polymorphisms in the HH gene were associated with HSCR and ARM in a Chinese population. HH gene variants (rs61730970, rs200798148 and rs146535482) were analyzed in whole blood samples from patients with HSCR and ARMs, as well as normal children (control group). The results suggested that, when the rs61730970, rs200798148 and rs146535482 alleles of the HH gene lacked particular single nucleotide polymorphisms (SNPs), the patients were associated with a greater risk of HSCR and/or ARM [HSCR: odds ratio (OR)=1.543, P=0.004; OR=1.494, P=0.007; rs146535482: OR=1.556, P=0.003, respectively. ARM: OR=1.528, P=0.045; OR=1.800, P=0.007; OR=1.743, P=0.009, respectively). Sequencing of rs61730970 and rs200798148 revealed a loss of heterozygosity and SNPs at these loci in patients with HSCR. Similarly, the sequencing of rs61730970 and rs146535482 revealed a loss of heterozygosity and SNPs at these loci in patients with ARM. Although preliminary, these results suggested that the HH gene may be involved in genetic interactions associated with the pathogenesis of HSCR and ARM.

[Relationship of Ghrelin gene polymorphism with congenital anorectal malformation and Hirschsprung disease].

OBJECTIVE: To explore the relationship of Ghrelin gene polymorphism with the occurrence of human anorectal malformations (ARMs) and Hirschsprung disease(HSCR). METHODS: PCR and DNA sequencing were used to detect the single nucleotide polymorphism (SNPs) of 3 loci (rs139684563, rs149447194, rs186599567) genotype of Ghrelin gene in 100 children with ARMs, 100 children with HSCR, and 100 healthy children (normal group). Genovariation and gene mutation were analyzed with case-control method. RESULTS: Three loci SNPs were in accordance with Hardy-Weinberg genetic equilibrium. No significant differences were found in rs139684563 allele and genotype frequencies between the cases and the normal groups (P>0.05). The allele and genotype frequencies of rs149447194 and rs186599567 were significantly different between cases and normal group (P<0.05). DNA sequencing results showed that wild-type homozygous deletion (176th and 191th base A deletion, respectively) were found in rs149447194 and rs186599567of ARMs and HSCR children, and single base substitution was detected in rs149447194 of ARMs children (194th codon nucleotide CCT to CTC). CONCLUSIONS: The rs149447194 and the rs186599567 polymorphism changes may be associated with the pathogenesis of ARMs and HSCR.

Effect of Personalized Nutrition Guidance on the Birth Rate of Fetal Macrosomia in Chinese Population: A Meta-analysis of Nine Randomized Controlled Trials.

The aim of the study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the efficacy of personalized nutrition guidance on birth rate of fetal macrosomia in the pooled studies. A comprehensive search was conducted to identify all eligible studies using the databases of PubMed, MEDLINE, Embase, Wanfang, Chongqing Weipu Database for Chinese Technical Periodicals and China National Knowledge Infrastructure and reference lists of relevant articles. The methodological quality of the included trials was assessed based on the Jadad scale. We used risk ratios (RRs) to assess the strength of the association, and 95 % confidence intervals (CIs) to evaluate the precision of the estimate. Heterogeneity, publication bias, and sensitivity analysis were also explored. A total of nine RCT studies, including 7,458 pregnant women, were included in the present meta-analysis. The overall results showed that personalized nutrition guidance significantly reduced the birth rate of fetal macrosomia (RR 0.289, 95 % CI 0.184-0.453, P < 0.01) in Chinese population. Simultaneously, publication bias was detected in this meta-analysis. The personalized nutrition guidance can significantly reduce the birth rate of fetal macrosomia. However, due to the limited number of RCTs, especially those with large sample size and multicenter that were quantitatively insufficient, further studies of high quality are required.

Communicating esophageal tubular duplication in a newborn infant.

We describe a communicating esophageal duplication in a newborn infant, without any other associated congenital anomalies. The diagnosis of esophageal duplication was achieved by a contrast study of the esophagus with diatrizoate and computed tomographic scan. Surgical excision of the esophageal duplication was carried out. At the 1-year follow-up examination, the patient was doing well.

Proteomic analysis of differentially expressed proteins between stenotic and normal colon segment tissues derived from patients with Hirschsprung's disease.

Hirschsprung's disease (HSCR) is the most common identifiable developmental disorder of the enteric nervous system. The present study was designed to analyze the differential proteomic patterns in stenotic colon segment tissues from patients with HSCR. We analyzed 20 paired stenotic and normal colon segment tissues from patients with HSCR, and identified 13 proteins from stenotic segment tissues peptide fingerprint mapping and SELDI MS that were separated using 2-DE. The protein levels of four selected proteins (α-actinin-4, ACTN4; myosin regulatory light chain interacting protein, MYLIP; fatty acid binding protein 7, FABP7; bone morphogenetic protein receptor type 1A, BMPR1A) were further validated by Western blot analysis. This study, investigating for the first time proteomic changes in stenotic colon segment tissues from patients with HSCR, provides potential markers or promising new candidate actors for the pathogenesis of HSCR.

Correlating of GSTM1, GSTT1, and GSTP1 genetic polymorphisms with the risk and expressions in children with isolated Hirschsprung disease.

PURPOSE: The present study aimed to examine an association between the glutathione S-transferases (GSTs) polymorphisms (GSTM1, GSTT1, and GSTP1) genetic polymorphisms with the risk and expression in children with isolated Hirschsprung disease (HD). METHODS: GSTM1, GSTT1, and GSTP1 genetic polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism analysis in 80 HD and 180 normal children (controls). The genic expressions were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The protein expressions were detected by Western blot. RESULTS: The GSTM1 null genotype especially is associated with a greater risk of HD (X(2) = 1.129, P = 0.288, OR = 0.851, 95% CI = 0.632-1.146). The GSTT1 null genotype especially is associated with a greater risk of HD (X(2) = 6.165, P = 0.013, OR = 1.472, 95% CI = 1.084-1.999). The GSTP1 null genotype especially is associated with a greater risk of HD (X(2) = 4.748, P = 0.029, OR = 0.701, 95% CI = 0.509-0.964). GSTP1 and GSTP1 expressions were higher than GSTM1 in HD patients. Positive expressive rate of the GSTT1 and GSTP1 were 40.56% and 56.67% in HD. The mRNA and protein expressions level of GSTT1 and GSTP1 genes were significantly higher in HD than controls (P < 0.05). Positive expressive rate of the GSTM1 was 10.56% in HD. The GSTM1 was low expressed between in HD and controls (P > 0.05). CONCLUSIONS: The GSTP1 genetic polymorphisms correlate to HD. We postulate that inherited gene deletion of GSTT1 and GSTP1 may produce increased genotoxic susceptibility for HD respectively, following exposure to xenobiotics that are substrates for these enzymes.

Embryonic development of the internal anal sphincter in rats with anorectal malformations.

BACKGROUND/PURPOSE: The embryogenesis of the internal anal sphincter (IAS) in anorectal malformations (ARMs) remains unclear. This study aimed to investigate the development of the smooth muscle in the terminus of the digestive tract in normal and abnormal rats. METHODS: Rat embryos with ARMs were generated by administration of ethylenethiourea to pregnant rats. The normal rat embryos and embryos with ARMs from E13.5 to E21 were serially sectioned in the sagittal plane and stained immunohistochemically using specific antibody to α-smooth muscle actin (SMA). Temporospatial study was carried out on circular muscle of the distal portion of the hindgut. RESULTS: α-Smooth muscle actin immunolabeling cells could not be observed in the hindgut on E13.5, E14, and E14.5. On E15, there were α-SMA immunolabeling circular muscle cells in the hindgut; and the distal portion of the circular muscle was not thickened in the normal and ARMs rats. From E16 onward, the smooth muscle with slight dilated terminus, which was characterized by the features of IAS, could be noted in the primitive anorectum. In the normal group, the circular muscle in the distal portion of the hindgut thickened slightly and became the musculature with shutter-like bundles. In the ARMs group, the α-SMA immunolabeling myogenic precursors of the smooth muscle could be observed in the primitive anorectum as well. The musculature was similar to that in the normal group. On E15 and E16, there was no significant difference in the development of the circular muscle in the 2 groups. Moreover, the terminus of the circular muscle in the hindgut did not reach the orificium fistulae in ARMs rats. From E17 onward, in ARMs rats, the funnel-shaped distal hindgut communicated the genitourinary tract with a narrow fistula; the dilated musculature at this portion thinned gradually and formed an acute angled extremity in the ARMs group rather than formed blunt extremity in the normal group; the terminus circular muscle in the dorsal hindgut reached the orificium fistulae. During the following gestational days, the circular muscle of the hindgut in both normal and ARMs rats continued its own tendency. CONCLUSION: The IAS primordium started to appear at the terminus of the hindgut on E15 in the 2 groups. The IAS in the ARMs group failed to develop as well as that in the normal group. The IAS dysplasia occurred in the late embryonic development (E17-E21).

[Mutation and expression of WNT8b gene and SHH gene in Hirschsprung disease].

OBJECTIVE: To investigate the relationship of WNT8b and SHH genes mutation and Hirschsprung disease(HSCR) in Chinese children. METHODS: Preoperative whole blood preparations in 72 children with sporadic HSCR from northeast China were collected(study group). Seventy-two healthy children were used as controls(matched for sex and age). Genomic DNA was obtained from peripheral blood. Exon 1 of WNT8b gene and the exon 1 of SHH gene were analyzed for gene mutation. The mutation products were automatically sequenced. The levels of WNT8b and SHH mRNA were detected by quantitative real-time PCR(qRT-PCR) in blood samples. RESULTS: On sequencing, 13 out of 72 children with HSCR had WNT8b gene mutation in the coding area, including heterozygosity deletion in 8 cases (11.1%) and base replacement in 5(6.9%). Eleven children with HSCR had SHH gene mutation in the coding area including heterozygosity deletion in 7 cases(9.7%) and base replacement in 4(5.6%). No mutations in WNT8b and SHH genes were found in the control group. The WNT8b and SHH mRNA levels were different between the study group and the control group(30.01±1.13 vs. 17.33±0.62, and 28.25±1.27 vs. 18.94±0.31, P<0.05). CONCLUSIONS: WNT8b and SHH mutations and abnormal expressions are present in the peripheral blood of children with sporadic HSCR. These two genes may be related to the development of sporadic HSCR in children in the northeastern China.

Experience in treating congenital esophageal atresia in China.

PURPOSE: The aim of the study was to evaluate our recent experience in treating esophageal atresia (EA) and the outcomes observed at a single center for pediatric surgery. MATERIALS AND METHODS: The records of infants with EA from 2006 to 2009 were reviewed. Birth weight, associated anomalies, details of management, complications, and outcomes were examined. RESULTS: Forty-eight consecutive infants with EA were identified from 2006 to 2009, of which 33 (69%) were boys. Mean birth weight was 2668 g (range, 1700-3800 g). Common associated malformations (35%) were cardiac anomalies, imperforate anus, limb anomalies, and chromosomal anomalies. Forty-seven were Gross type C, and one was Gross type A. Forty-five infants underwent ligation of the tracheoesophageal fistula and end-to-side primary anastomosis, and one received a colonic interposition. Six patients died (12.5% mortality). Three died before or during operation because of severe pneumonia and complex cardiac anomalies, and 3 died during recovery (within 1 month after repair) because of aspiration and severe pneumonia (early postoperative mortality was 6.67%). Complications included pneumonia, anastomotic leakage (16%, all recovered after conservative treatment), wound sepsis (11%), recurrent tracheoesophageal fistula (9%) (3/4 recovered after conservative treatment), anastomotic stricture (10%), and gastroesophageal reflux in about 2 of 3 patients. Preoperative computed tomographic imaging and 3-dimensional graphic reconstruction used in 15 patients were useful. CONCLUSIONS: Most patients with EA have excellent short- to midterm surgical outcomes. The main factors for mortality are complex cardiac anomalies, aspiration, and pneumonia. Computed tomographic imaging and 3-dimensional graphic reconstruction can provide surgeons with excellent preoperative reference about the anatomy of the defect. Most anastomotic related complications resolve with conservative treatment. Patients of low-risk prognosis group with type A and long gap EA can be managed with a primary colonic interposition with good results. The main midterm complications are gastroesophageal reflux and stricture.

Rectosigmoid tubular duplication presenting as perineal sepsis in a neonate.

Tubular rectal duplication is a very rare congenital anomaly. We report a case of tubular rectal duplication in a newborn baby who presented with perianal sepsis. The diagnosis was confirmed by barium enema, magnetic resonance imaging, and at operation. We performed total mucosectomy through a posterior sagittal incision combined with laparotomy. The patient was doing quite well at 17-month follow-up examination.

Expression of EphB2 in the development of anorectal malformations in fetal rats.

PURPOSE: The receptor tyrosine kinase of the Eph family is a large group of highly conserved molecules that function in diverse intercellular recognition events. It has been reported that EphB2 is related to caudal remodeling events. The aim of this study is to investigate EphB2 expression in anorectal development in normal and rat embryos with anorectal malformations (ARMs) and attempt to define its role in anorectal morphogenesis. METHODS: The ethylenethiourea (ETU) rat model of the ARMs was used in this study. Immunohistochemical analyses and real time quantitative polymerase chain reaction (PCR) were carried out to investigate EphB2 protein localizations and messenger RNA (mRNA) expression levels. (1) Rat embryos with ARMs were obtained by treating pregnant rats (n = 24) with administration of ETU on gestation day (Gd) 10. Normal rat embryos (n = 111) and embryos treated by ETU without ARMs (n = 90) were the control groups, and embryos with ARMs (n = 108) from Gd13 to Gd16 were divided according to the sections taken from specimens. (2) Embryos were sequentially sectioned in the sagittal and transversal planes before staining with a specific antibody to EphB2. Spatiotemporal study was carried out on EphB2 expression. (3) Individual frozen sections were used to manually microdissect the cloaca and anorectal specimens for total RNA extraction. EphB2 expression was evaluated by real time quantitative PCR. RESULTS: On the immunologic labeling study, EphB2 expression was confined to the cloaca in control groups, whereas EphB2 expression was mainly located at the urorectal septum (URS) and cloacal membrane on Gd13 and Gd14. The increased positive expression was observed in the fused tissue of the URS and cloacal membrane on Gd15. On Gd16, the anal membrane broke down, and the rectum was able to be in contact with the anus, and EphB2 expression was then noted in mucous membrane of rectum. EphB2 expression was seen in the cloacal and anorectal tissues of embryos with ARMs. By integrated optical density (IOD) measurement, IOD value of EphB2 protein was significantly lower in the ARM group than that in the control groups on Gd13 to Gd16 (P < .05), respectively. As shown by real time quantitative PCR, EphB2 expression was detected in 3 groups. EphB2 mRNA level increased on Gd13 to Gd16 but gradually decreased after Gd16. The expression level of EphB2 mRNA in the ARM embryos was lower on Gd13 to Gd16 than that in control groups (P < .05). CONCLUSIONS: EphB2 expression decreased in the ARM embryos and was confined to URS and cloaca, whereas it was higher in control group. Our data thus indicated that EphB2 molecules possibly contributed to the anorectal morphogenesis and the decreased expression of EphB2 might be related to the development of ARMs.

Embryonic development of the striated muscle complex in rats with anorectal malformations.

PURPOSE: Many patients with anorectal malformations (ARMs) continue to have postoperative anal dysfunction. The striated muscle complex (SMC) is one of the most important factors that influence defecation function. To explore the development of SMC in ARMs, the authors investigated the pelvic muscle development in rat embryos affected with ARMs. METHODS: Anorectal malformation embryos were induced by ethylenethiourea on the 10th gestational day (E10). Normal rat embryos and embryos with ARMs from E13 to E21 were serial-sectioned in the sagittal, transverse, and coronal planes, stained with H&E and immunohistochemistry staining using specific antibodies to myogenin. Temporal and spatial sequence was carried out on SMC. RESULTS: On E16, in normal group, SMC appeared fibroid structure in normal rats; SMC arose from bulbocavernosus muscle and ran backward, parallel to the perineal skin, and loosely surrounded the anal canal and urethra. Although in ARM rats the rectum was absent, the location and appearance of SMC were similar to the normal group. On E18, in normal group, SMC musculature became much thicker than on E16 and SMC gave off 2 branches outside anterior to the rectum. Striated muscle complex surrounded the rectum more tightly. However, in ARM rats, obvious changes of SMC could be noted. In detail, SMC in ARMs were characterized by abnormal location, appearance, and path. Striated muscle complex shifted obviously cephalad, ventrally, and medianward and converged inferior to the rectal terminus and posterior to the urethra. The distance between SMC musculature and the perineal skin increased. This structure surrounded the fiberlike tissue posterior to the urethra. Under high-power view, there was connective tissue among intermuscular bundles, and the structure was disordered. During the following gestational days, SMC in normal and ARM groups continued their own tendency, respectively. CONCLUSIONS: This study illustrated the development of the SMC in normal and ARM rats. On E16, the location and appearance of SMC in ARM rats were similar to the normal rats, and at this time, the ectopic rectal orifice could be noted. From E18 on, the maldevelopment of SMC could be observed in ARM rats. These observations suggested that the morphological changes of SMC take place after the occurrence of abnormal anorectum.