Shu-Cheng Zhang

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.

Decreased enteric fatty acid amide hydrolase activity is associated with colonic inertia in slow transit constipation

Constipation is one of the most common chronic digestive complaints. Gastrointestinal transit studies have divided it into three patterns: normal transit, slow transit constipation (STC), and outlet obstruction. It has been demonstrated that STC patients respond poorly to standard therapies, and the etiology of STC remains poorly understood. Animal studies have also shown that fatty acid amide hydrolase (FAAH) controls intestinal motility through its putative receptors or non‐receptor‐mediated pathways. However, the role of FAAH in STC has not been elaborated.

Constipation Is Associated With Spina Bifida Occulta in Children

BACKGROUND & AIMS Spina bifida occulta (SBO) is a common developmental variant. The aim of this study was to re-examine the possible association between SBO and constipation in children. METHODS A total of 113 children with constipation underwent plain abdominal radiography, anorectal manometry, neurophysiologic study, electromyography testing, and colonic transit study. Eighty-six were diagnosed with functional constipation (FC) and 27 were diagnosed with nonretentive fecal incontinence (NRFI). The incidence of SBO in these children was compared with 226 sex- and age-matched controls. Twenty-four SBO children with either FC or NRFI also underwent individualized biofeedback training and electric stimulation therapy based on the investigation results. RESULTS The incidence of SBO in the FC and NRFI groups was 47.7% and 77.8%, respectively. Statistically, this is significantly higher than that of the control group (chi-square, 23.9%; P < .05). Compared with the FC or NRFI children without SBO, the FC and NRFI children with SBO had decreased vector volumes and electromyography amplitudes, increased rectal sensory thresholds, and prolonged latency of pudendo-anal reflex. All 24 children who underwent individualized biofeedback training and electrical stimulation treatment had sustained symptomatic improvement with less straining, fewer incomplete bowel movements, and less abdominal pain. The recovery rate was 79.2% (19 of 24). CONCLUSIONS Constipation in children is associated with increased incidence of SBO. Individualized biofeedback combined with electrical stimulation improves both the symptoms and the objective anorectal function measurements.

Engineered measles virus Edmonston strain used as a novel oncolytic viral system against human hepatoblastoma

BackgroundHepatoblastoma (HB) is the most common primary, malignant pediatric liver tumor in children. The treatment results for affected children have markedly improved in recent decades. However, the prognosis for high-risk patients who have extrahepatic extensions, invasion of the large hepatic veins, distant metastases and very high alpha-fetoprotein (AFP) serum levels remains poor. There is an urgent need for the development of novel therapeutic approaches.MethodsAn attenuated strain of measles virus, derived from the Edmonston vaccine lineage, was genetically engineered to produce carcinoembryonic antigen (CEA). We investigated the antitumor potential of this novel viral agent against human HB both in vitro and in vivo.ResultsInfection of the Hep2G and HUH6 HB cell lines, at multiplicities of infection (MOIs) ranging from 0.01 to 1, resulted in a significant cytopathic effect consisting of extensive syncytia formation and massive cell death at 72–96 h after infection. Both of the HB lines overexpressed the measles virus receptor CD46 and supported robust viral replication, which correlated with CEA production. The efficacy of this approach in vivo was examined in murine Hep2G xenograft models. Flow cytometry assays indicated an apoptotic mechanism of cell death. Intratumoral administration of MV-CEA resulted in statistically significant delay of tumor growth and prolongation of survival.ConclusionsThe engineered measles virus Edmonston strain MV-CEA has potent therapeutic efficacy against HB cell lines and xenografts. Trackable measles virus derivatives merit further exploration in HB treatment.

Engineered measles virus Edmonston strain used as a novel oncolytic viral system against human neuroblastoma through a CD46 and nectin 4-independent pathway

Neuroblastoma (NB) is the most common extracranial solid tumor in children. In this study, we investigated the potential antitumor capability of the engineered Edmonston strain of the carcinoembryonic antigen-expressing measles virus (MV-CEA) against human NB. The infection of a variety of NB cell lines, including SK-N-SH, SMS-KCNR, and primary NB cells, resulted in significant cytopathic effects. None of the NB cell lines showed an overexpression of the measles virus receptor CD46 and nectin 4, but the cell lines did support robust viral replication. The efficacy of this approach was examined in murine SK-N-SH xenograft models. Flow cytometry and TUNEL assays indicated an apoptotic mechanism of cell death. In summary, MV-CEA has potent therapeutic efficacy against NB mediated by a CD46- and nectin 4-independent pathway.

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 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).

Clinical and Ultrasonographic Features of Secondary Intussusception in Children

AbstractObjectivesThe aim of this study was to review the ultrasonographic features of secondary intussusception (SI) in children and assess the value of ultrasound in the diagnosis of pediatric SI.MethodsThe authors performed a retrospective analysis on the ultrasound findings of 1977 cases of primary intussusception (PI) and 37 cases of SI in children. The SI cases were diagnosed by ultrasonography and confirmed by laparotomy or histopathologic diagnosis. The clinical and ultrasonographic features were analyzed and compared between these two groups.ResultsThe age, no flatus or defecation, position, diameter and length of intussusception, the presence of free intraperitoneal liquid, and intestinal dialation at the proximal end present, all contributed to the differentiation between PI and SI (all P < 0.05). Ultrasound was able to demonstrate the pathological lead point (PLP) shadows in all of the 37 SI cases, either in the cervical part or intussusceptum of the intussusception. Among the 37 SI patients, 21 cases (56.8 %) were accurately categorized with lesions, including intestinal polyps, cystic intestinal duplication, intestinal wall lymphoma, and a small part of Meckels diverticulum.ConclusionsUltrasound can be used as a feasible and effective method to discriminate PI from SI. Once the PLP is detected, a definite diagnosis can be made.Key Points• The clinical and ultrasonographic features were compared between SI and PI.• The age, location, diameter and length of intussusception, and intestinal dilation were distinguishing features. • The causes of SI were found to be polyps, intestinal duplication, lymphoma, and Meckels diverticulum. • Ultrasound can be used as an important method to diagnose SI. • Demonstration and confirmation of PLP are vital to diagnosing SI.

Ultrasonographic dimensions of the common bile duct in Chinese children: Results of 343 cases

BACKGROUND At present, the diagnostic criteria of congenital cholangiectasis are still vague. PURPOSE The aim of this study was to assess the diameter references of the common bile duct (CBD) in pediatric population in different age groups with ultrasound. METHODS The diameter of the common bile duct was measured with ultrasound in 343 Chinese Han children aged 1 day to 14 years (mean: 3.2 years, median: 2.8 years) who were all free of hepatic and biliary tract disease. The ultrasound records, gender, and age were collected for reviewed analysis. RESULTS A total of 343 children were included, and the CBD was clearly detected in 322 cases (93.9%). The mean diameter of this population was 1.58 ± 0.70 mm. (ranging from 0.4 to 4.4mm). Spearman correlation analysis showed that the diameter of CBD was positively associated with age (r=0.573, P<0.001). The percentile method demonstrated that the diameter references of CBD was as follows: ≤ 1 years: ≤ 2.26 mm; ≤ 4 years: ≤ 2.99 mm; ≤ 7 years: ≤ 3.03 mm; and ≤ 14 years: ≤ 4.10mm. CONCLUSIONS There was a close correlation between CBD width and the age. The range of CBD widths in each age group will be helpful in the diagnosis of biliary dilatation in childhood.

Primary yolk sac tumor in diaphragm

Yolk sac tumor (YST), also known as endodermal sinus tumor, is the most common pure malignant germ cell tumor in young children. Although most of the YST occur in gonads, about 20 % are found in the extragonadal sites including mediastinum, vagina, cervix, vulva, pelvis, liver, prostate, and diaphragm. Primary YST of the diaphragm in children is very rare. Here, we report a primary diaphragmatic yolk sac tumor in a 21-month-old boy. This is, to our knowledge, the sixth documented case of this nature.