Size matters: Large copy number losses in Hirschsprung disease patients reveal genes involved in enteric nervous system development.

Hirschsprung disease (HSCR) is a complex genetic disease characterized by absence of ganglia in the intestine. HSCR etiology can be explained by a unique combination of genetic alterations: rare coding variants, predisposing haplotypes and Copy Number Variation (CNV). Approximately 18% of patients have additional anatomical malformations or neurological symptoms (HSCR-AAM). Pinpointing the responsible culprits within a CNV is challenging as often many genes are affected. Therefore, we selected candidate genes based on gene enrichment strategies using mouse enteric nervous system transcriptomes and constraint metrics. Next, we used a zebrafish model to investigate whether loss of these genes affects enteric neuron development in vivo. This study included three groups of patients, two groups without coding variants in disease associated genes: HSCR-AAM and HSCR patients without associated anomalies (HSCR-isolated). The third group consisted of all HSCR patients in which a confirmed pathogenic rare coding variant was identified. We compared these patient groups to unaffected controls. Predisposing haplotypes were determined, confirming that every HSCR subgroup had increased contributions of predisposing haplotypes, but their contribution was highest in isolated HSCR patients without RET coding variants. CNV profiling proved that specifically HSCR-AAM patients had larger Copy Number (CN) losses. Gene enrichment strategies using mouse enteric nervous system transcriptomes and constraint metrics were used to determine plausible candidate genes located within CN losses. Validation in zebrafish using CRISPR/Cas9 targeting confirmed the contribution of UFD1L, TBX2, SLC8A1, and MAPK8 to ENS development. In addition, we revealed epistasis between reduced Ret and Gnl1 expression and between reduced Ret and Tubb5 expression in vivo. Rare large CN losses-often de novo-contribute to HSCR in HSCR-AAM patients. We proved the involvement of six genes in enteric nervous system development and Hirschsprung disease.

Direct Interaction of Sox10 With Cadherin-19 Mediates Early Sacral Neural Crest Cell Migration: Implications for Enteric Nervous System Development Defects.

BACKGROUND AND AIMS: The enteric nervous system, which regulates many gastrointestinal functions, is derived from neural crest cells (NCCs). Defective NCC migration during embryonic development may lead to enteric neuropathies such as Hirschsprung's disease (hindgut aganglionosis). Sox10 is known to be essential for cell migration but downstream molecular events regulating early NCC migration have not been fully elucidated. This study aimed to determine how Sox10 regulates migration of sacral NCCs toward the hindgut using Dominant megacolon mice, an animal model of Hirschsprung's disease with a Sox10 mutation. METHODS: We used the following: time-lapse live cell imaging to determine the migration defects of mutant sacral NCCs; genome-wide microarrays, site-directed mutagenesis, and whole embryo culture to identify Sox10 targets; and liquid chromatography and tandem mass spectrometry to ascertain downstream effectors of Sox10. RESULTS: Sacral NCCs exhibited retarded migration to the distal hindgut in Sox10-null embryos with simultaneous down-regulated expression of cadherin-19 (Cdh19). Sox10 was found to bind directly to the Cdh19 promoter. Cdh19 knockdown resulted in retarded sacral NCC migration in vitro and ex vivo, whereas re-expression of Cdh19 partially rescued the retarded migration of mutant sacral NCCs in vitro. Cdh19 formed cadherin-catenin complexes, which then bound to filamentous actin of the cytoskeleton during cell migration. CONCLUSIONS: Cdh19 is a direct target of Sox10 during early sacral NCC migration toward the hindgut and forms cadherin-catenin complexes which interact with the cytoskeleton in migrating cells. Elucidation of this novel molecular pathway helps to provide insights into the pathogenesis of enteric nervous system developmental defects.

CD177+ cells produce neutrophil extracellular traps that promote biliary atresia.

BACKGROUND & AIMS: We have previously reported on the potential pathogenic role of neutrophils in biliary atresia (BA). Herein, we aimed to delineate the role of CD177+ neutrophils in the pathogenesis of BA. METHODS: Immune cells from the livers of mice with rhesus rotavirus-induced BA were analysed. Single-cell RNA-sequencing was performed to specifically analyse Gr-1+ (Ly6C/Ly6G+) cells in the liver. Gene expression profiles of CD177+ cells were analysed using the Smart-Seq RNA-sequencing method, and the pathogenesis of BA was examined in Cd177-/- mice. Neutrophil extracellular trap (NET) inhibitors were used to determine the role of CD177+ cell-derived NETs in BA-associated bile duct damage, and a pilot clinical study evaluated the potential effects of N-acetylcysteine on NET release in BA. RESULTS: Increased levels of Gr-1+ cells were observed in the livers of mice with rhesus rotavirus-induced BA. RNA-sequencing analysis revealed that CD177+ cells were the main population of Gr-1+ cells and expressed elevated levels of both interferon-stimulated and neutrophil degranulation genes. Cd177-/- BALB/c mice exhibited delayed disease onset and reduced morbidity and mortality. High numbers of mitochondria were detected in CD177+ cells derived from mice with BA; these cells were associated with increased levels of reactive oxygen species and increased NET formation, which induced the apoptosis of biliary epithelial cells in cocultures. In a pilot clinical study, the administration of N-acetylcysteine to patients with BA reduced CD177+ cell numbers and reactive oxygen species levels, indicating a potential beneficial effect. CONCLUSIONS: Our data indicate that CD177+ cells play an important role in the initiation of BA pathogenesis via NET formation. CLINICAL TRIAL REGISTRATION: The pilot study of N-acetylcysteine treatment in patients with BA was registered on the Chinese Clinical Trial Registry (ChiCTR2000040505). LAY SUMMARY: Neutrophils (a type of innate immune cell, i.e. an immune cell that doesn't target a specific antigen) are thought to play a role in the development of biliary atresia (a rare but potentially lethal condition of the bile ducts that occurs in infants). Herein, we found that neutrophils expressing a particular protein (CD177) played an important role in bile duct damage by releasing a special structure (NET) that can trap and kill pathogens but that can also cause severe tissue damage. A pilot study in patients with biliary atresia showed that inhibiting NETs could have a beneficial effect.

Vulnerability and resilience in children during the COVID-19 pandemic.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is having a profound impact on the health and development of children worldwide. There is limited evidence on the impact of COVID-19 and its related school closures and disease-containment measures on the psychosocial wellbeing of children; little research has been done on the characteristics of vulnerable groups and factors that promote resilience. METHODS: We conducted a large-scale cross-sectional population study of Hong Kong families with children aged 2-12 years. Parents completed an online survey on family demographics, child psychosocial wellbeing, functioning and lifestyle habits, parent-child interactions, and parental stress during school closures due to COVID-19. We used simple and multiple linear regression analyses to explore factors associated with child psychosocial problems and parental stress during the pandemic. RESULTS: The study included 29,202 individual families; of which 12,163 had children aged 2-5 years and 17,029 had children aged 6-12 years. The risk of child psychosocial problems was higher in children with special educational needs, and/or acute or chronic disease, mothers with mental illness, single-parent families, and low-income families. Delayed bedtime and/or inadequate sleep or exercise duration, extended use of electronic devices were associated with significantly higher parental stress and more psychosocial problems among pre-schoolers. CONCLUSIONS: This study identifies vulnerable groups of children and highlights the importance of strengthening family coherence, adequate sleep and exercise, and responsible use of electronic devices in promoting psychosocial wellbeing during the COVID-19 pandemic.

Pattern of anatomic disorder and surgical management of anorectal prolapse in anorectal malformation.

AIM: Due to the paucity of data and controversy regarding the etiology and surgical approach for managing anorectal prolapse (ARP) after anorectoplasty, we sought to investigate the underlying anatomic disorder and the surgical outcome in managing this challenging complication. METHODS: We performed a retrospective study on 83 patients with ARP related to anorectal malformations (ARM). Logistic regression analyses were performed to detect the risk factors for the ARP severity. Surgical procedures were stratified according to identified anatomical abnormalities and surgical outcomes were analyzed. RESULTS: 50 patients (62.7%) had high-type ARM. The original anorectoplasty had a higher rate of ARP in laparoscopic-assisted anorectoplasty (n = 49, 59.0%) versus posterior sagittal anorectoplasty (n = 11, 13.3%). ARP was associated with rectal fat hyperplasia (67.5%), dilated muscular tunnel (79.5%), longitudinal muscle (LM) discontinuity (16.9%), rectal dilation (22.9%), mislocated anus (7.2%), and excessive mobile mesorectum (3.6%). Based on the ARP severity, the patients were divided into a severe group (Group 1, n = 38) and a moderate group (Group 2, n = 45). Binary logistic regression analysis showed that hyperplasia rectal fat (OR 4.55, 95% CI 1.16-17.84), rectal dilation (OR 4.21, 95% CI 1.05-16.94), and high-type ARM (OR 2.90, 95% CI 1.14-7.39) were independent risk factors for the development of severe ARP. Complications after stratified surgical repair included wound infection in six patients (7.2%), anal stenosis in one patient (1.2%), and ARP recurrence in two patients (2.4%). Twenty-six patients without colostomy before prolapse repair were followed up for 2 to 12 years. All the patients maintained voluntary bowel movements. Following ARP repair, there was an overall higher rate of no soiling or grade 1 soiling (88.5 vs. 65.4%), but 3 of 12 patients with grade 2 constipation were upgraded to grade 3. CONCLUSION: Our study shows that ARM-related anorectal prolapse is associated with excessive rectum, hyperplasia of rectal fat, mobile mesorectum, loose muscular tunnel, LM discontinuity, and anal mislocation. Surgical repair with techniques stratified according to the patients' underlying risk factors is effective to prevent recurrence and improve the soiling continence.

Down-regulation of STAT3 enhanced chemokine expression and neutrophil recruitment in biliary atresia.

Biliary atresia (BA) is an immune-related disorder and signal transducer and activator of transcription 3 (STAT3) is a key signalling molecule in inflammation. The present study was designed to clarify the function of STAT3 in BA. STAT3 expression was examined in patients and a mouse BA model in which STAT3 levels were further altered with a specific inhibitor or activator. Neutrophil accumulation and the levels of the neutrophil chemoattractants (C-X-C motif) ligand 1 (CXCL1) and IL-8 were determined. The effects of STAT3 inhibition on IL-8 expression were examined in human biliary epithelial cell (BEC) cultures. Functional changes in liver STAT3+ neutrophils in the mouse model were analysed with 10× single cell RNA-seq methods. Results showed STAT3 and p-STAT3 expression was reduced in BA liver tissue compared with control samples. Administration of a STAT3 inhibitor increased jaundice and mortality and reduced body weight in BA mice. In contrast, the STAT3 activator ameliorated BA symptoms. Extensive neutrophil accumulation together with CXCL1 up-regulation, both of which were suppressed by an anti-CXCL1 antibody, were observed in the STAT3 inhibitor-treated group. Recombinant IL-8 administration increased disease severity in BA mice, and the STAT3 activator had the reverse effect. Inhibiting STAT3 increased apoptosis of human BECs together with up-regulated IL-8 expression. RNA-seq analysis revealed reduced the numbers of STAT3 expressing neutrophil in BA which was accompanied by marked enhanced interferon-related antiviral activities. In conclusion, STAT3 reduction, enhanced IL-8 and CXCL1 expression and promoted the accumulation of interferon-responsive neutrophils resulting in BEC damage in BA.

De novo mutations in Caudal Type Homeo Box transcription Factor 2 (CDX2) in patients with persistent cloaca.

The cloaca is an embryonic cavity that is divided into the urogenital sinus and rectum upon differentiation of the cloacal epithelium triggered by tissue-specific transcription factors including CDX2. Defective differentiation leads to persistent cloaca in humans (PC), a phenotype recapitulated in Cdx2 mutant mice. PC is linked to hypo/hyper-vitaminosis A. Although no gene has ever been identified, there is a strong evidence for a genetic contribution to PC. We applied whole-exome sequencing and copy-number-variants analyses to 21 PC patients and their unaffected parents. The damaging p.Cys132* and p.Arg237His de novo CDX2 variants were identified in two patients. These variants altered the expression of CYP26A1, a direct CDX2 target encoding the major retinoic acid (RA)-degrading enzyme. Other RA genes, including the RA-receptor alpha, were also mutated. Genes governing the development of cloaca-derived structures were recurrently mutated and over-represented in the basement-membrane components set (q-value < 1.65 × 10-6). Joint analysis of the patients' profile highlighted the extracellular matrix-receptor interaction pathway (MsigDBID: M7098, FDR: q-value < 7.16 × 10-9). This is the first evidence that PC is genetic, with genes involved in the RA metabolism at the lead. Given the CDX2 de novo variants and the role of RA, our observations could potentiate preventive measures. For the first time, a gene recapitulating PC in mouse models is found mutated in humans.

A Comparison Between Chinese Children Infected with Coronavirus Disease-2019 and with Severe Acute Respiratory Syndrome 2003.

OBJECTIVES: To compare the clinical and laboratory features of severe acute respiratory syndrome 2003 (SARS) and coronavirus disease 2019 (COVID-19) in 2 Chinese pediatric cohorts, given that the causative pathogens and are biologically similar. STUDY DESIGN: This is a cross-sectional study reviewing pediatric patients with SARS (n = 43) and COVID-19 (n = 244) who were admitted to the Princess Margaret Hospital in Hong Kong and Wuhan Children's Hospital in Wuhan, respectively. Demographics, hospital length of stay, and clinical and laboratory features were compared. RESULTS: Overall, 97.7% of patients with SARS and 85.2% of patients with COVID-19 had epidemiologic associations with known cases. Significantly more patients with SARS developed fever, chills, myalgia, malaise, coryza, sore throat, sputum production, nausea, headache, and dizziness than patients with COVID-19. No patients with SARS were asymptomatic at the time of admission, whereas 29.1% and 20.9% of patients with COVID-19 were asymptomatic on admission and throughout their hospital stay, respectively. More patients with SARS required oxygen supplementation than patients with COVID-19 (18.6 vs 4.7%; P = .004). Only 1.6% of patients with COVID-19 and 2.3% of patients with SARS required mechanical ventilation. Leukopenia (37.2% vs 18.6%; P = .008), lymphopenia (95.4% vs 32.6%; P < .01), and thrombocytopenia (41.9% vs 3.8%; P < .001) were significantly more common in patients with SARS than in patients with COVID-19. The duration between positive and negative nasopharyngeal aspirate and the length in hospital stay were similar in patients with COVID-19, regardless of whether they were asymptomatic or symptomatic, suggesting a similar duration of viral shedding. CONCLUSIONS: Children with COVID-19 were less symptomatic and had more favorable hematologic findings than children with SARS.

Laparoscopic surgical technique to enhance the management of anorectal malformations: 330 cases' experience in a single center.

PURPOSE: Laparoscopic-assisted anorectoplasty (LAARP) is considered to benefit the patients with vesico-prostatic fistula. The aim of this study is to present the details of our LAARP technique for improving the short- and long-term outcomes in the patients with high and intermediate types of anorectal malformations (ARMs). METHODS: 330 patients with high-type (174 cases) and intermediate-type (156 cases) anorectal malformation (aged 8 days to 15 years) underwent LAARP from 2001 to 2019. LAARP was performed for full mobilization and resection of the dilated rectum, intra-rectal closure of the fistula, visualization, and enlargement of the center of the longitudinal muscle tube (LMT) from pelvic and perineal aspects. RESULTS: LAARP was performed in all patients and no patient was converted to open procedure. The urethral diverticulum was found in three patients (1.02%, 3/294) according to postoperative protocol voiding cystourethrogram but was not associated with any symptoms such as urinary tract infection and dysuria. Rectal prolapse requiring surgical intervention developed in 25 (7.6%) of 330 patients. Anal stricture occurred in three patients and re-do anoplasty was performed 5 months after LAARP. Anal retraction occurred in two patients and re-pull-through was conducted at 5 and 6 days, respectively, after LAARP. 228 patients who were older than 3 years were followed up. The median follow-up period was 5.8 years (range 3-15 years). 217 patients (95.2%) had voluntary bowel movements; 202 patients (88.6%) were free from soiling or with grade 1 soiling; 30 patients (13.6%) and 25 patients (11.3%) suffered from grade 1 and grade 2 constipation, respectively, while no patient had grade 3 constipation. CONCLUSION: Our experience demonstrates that the LAARP has advantages on rectal mobilization and resection, intra-rectal fistula closure and accurate tunnel formation in the LMT with minimal trauma. The improvement of the short-term and long-term outcomes after LAARP has been shown not only for high-type ARM but also for intermediate-type ARM.

The Role of Neonatal Gr-1+ Myeloid Cells in a Murine Model of Rhesus-Rotavirus-Induced Biliary Atresia.

Activation of innate immunity together with cholangiocyte damage occurs in biliary atresia (BA). However, detailed information on the inflammatory cells involved is lacking. This study investigates both the pathophysiology of CD11b+Gr-1+ cells in a mouse model of BA and their presence in BA patients. CD11b+Gr-1+ cells were targeted by an anti-Ly6G antibody in murine BA induced by inoculation with rhesus rotavirus. Expression of the Ly6G homolog CD177+ was examined in biopsies from BA patients. The symptoms of BA were ameliorated, and survival was prolonged in those mice receiving 5 to 10 µg of antibody per mouse every 3 days for four times compared with the mice treated with virus alone. However, the mice later developed chronic BA with persistent low body weight and jaundice. Hepatic inflammatory cells were reduced compared with acute BA. Blockade of extrahepatic bile ducts occurred, whereas intrahepatic ductules were partially preserved, and a progressive increase in liver fibrosis was observed. High levels of CD11b+Gr-1+ cells were present in these mice. The administration of an anti-Ly6G antibody again in those chronic BA mice reduced jaundice and restored body weight. In BA patients CD177+ cells were highly expressed in the liver. Our data suggest that the chronic mouse BA model shares key characteristics with clinical BA and indicates the importance of CD11b+Gr-1+ cells in the initiation and progression of BA.

Trans-ethnic meta-analysis of genome-wide association studies for Hirschsprung disease.

Hirschsprung disease (HSCR) is the most common cause of neonatal intestinal obstruction. It is characterized by the absence of ganglia in the nerve plexuses of the lower gastrointestinal tract. So far, three common disease-susceptibility variants at the RET, SEMA3 and NRG1 loci have been detected through genome-wide association studies (GWAS) in Europeans and Asians to understand its genetic etiologies. Here we present a trans-ethnic meta-analysis of 507 HSCR cases and 1191 controls, combining all published GWAS results on HSCR to fine-map these loci and narrow down the putatively causal variants to 99% credible sets. We also demonstrate that the effects of RET and NRG1 are universal across European and Asian ancestries. In contrast, we detected a European-specific association of a low-frequency variant, rs80227144, in SEMA3 [odds ratio (OR) = 5.2, P = 4.7 × 10-10]. Conditional analyses on the lead SNPs revealed a secondary association signal, corresponding to an Asian-specific, low-frequency missense variant encoding RET p.Asp489Asn (rs9282834, conditional OR = 20.3, conditional P = 4.1 × 10-14). When in trans with the RET intron 1 enhancer risk allele, rs9282834 increases the risk of HSCR from 1.1 to 26.7. Overall, our study provides further insights into the genetic architecture of HSCR and has profound implications for future study designs.

Actionable secondary findings from whole-genome sequencing of 954 East Asians.

Recently, the American College of Medical Genetics (ACMG) recommended the return of actionable secondary findings detected from clinical sequencing. The reported frequency of secondary findings in Asian populations were highly variable and it is unclear whether the uniformity in coverage offered by whole-genome sequencing (WGS) may impact the estimate. In this analysis, we aimed to refine the rate of secondary findings on East Asians through a large-scale WGS study. We classified 1256 protein-altering or splicing variants of the 59 actionable genes detected from WGS of 954 East Asians in strict accordance with the ACMG and the Association for Molecular Pathology guidelines. A total of 21 pathogenic or likely pathogenic variants were detected in 24 of the 954 East Asian genomes with an estimate of 2.5% of East Asians carrying actionable variants. Although the overall estimate of secondary findings was consistent with those reported for non-East Asian ethnicities, genetic and allelic heterogeneity was observed. WGS offers a wider breadth of coverage over WES, which highlights the need to further investigate the variable sensitivity of WES and WGS in the detection of secondary findings. Identifying secondary findings in populations underrepresented in previous genetic literature might improve variant interpretation and has a profound impact on local decision-making with regard to the cost-effectiveness of returning the secondary findings from clinical sequencing.

Advances in paediatric urology.

Paediatric urological surgery is often required for managing congenital and acquired disorders of the genitourinary system. In this Series paper, we highlight advances in the surgical management of six paediatric urological disorders. The management of vesicoureteral reflux is evolving, with advocacy ranging from a less interventional assessment and antimicrobial prophylaxis to surgery including endoscopic injection of a bulking agent and minimally invasive ureteric reimplantation. Evidence supports early orchidopexy to improve fertility and reduce malignancy in boys with undescended testes. A variety of surgical techniques have been developed for hypospadias, with excellent outcomes for distal but not proximal hypospadias. Pelvi-ureteric junction obstruction is mostly detected prenatally; indications for surgery have been refined with evidence, and minimally invasive pyeloplasty is now standard. The outlook for patients with neurogenic bladder has been transformed by a combination of clean intermittent catheterisation, algorithms of diagnostic investigations, and innovative medical and surgical therapies. Posterior urethral valves are associated with considerable mortality; fetal diagnosis allows stratification of candidates for intervention, but ongoing bladder dysfunction in patients after valve ablation remains a cause of long-term morbidity.

Advances in paediatric gastroenterology.

Recent developments in paediatric gastrointestinal surgery have focused on minimally invasive surgery, the accumulation of high-quality clinical evidence, and scientific research. The benefits of minimally invasive surgery for common disorders like appendicitis and hypertrophic pyloric stenosis are all supported by good clinical evidence. Although minimally invasive surgery has been extended to neonatal surgery, it is difficult to establish its role for neonatal disorders such as oesophageal atresia and biliary atresia through clinical trials because of the rarity of these disorders. Advances in treatments for biliary atresia and necrotising enterocolitis have been achieved through specialisation, multidisciplinary management, and multicentre collaboration in research; similarly robust clinical evidence for other rare gastrointestinal disorders is needed. As more neonates with gastrointestinal diseases survive into adulthood, their long-term sequelae will also need evidence-based multidisciplinary care. Identifying cures for long-term problems of a complex developmental anomaly such as Hirschsprung's disease will rely on unravelling its pathogenesis through genetics and the development of stem-cell therapy.

SRY interference of normal regulation of the RET gene suggests a potential role of the Y-chromosome gene in sexual dimorphism in Hirschsprung disease.

The Hirschsprung disease (HSCR) is a complex congenital disorder, arising from abnormalities in enteric nervous system (ENS) development. There is a gender disparity among the patients, with the male to female ratio as high as 5 : 1. Loss-of-function mutations of HSCR genes and haploinsufficiency of their gene products are the primary pathogenic mechanisms for disease development. Recent studies identified over half of the HSCR disease susceptibility genes as targets for the sex-determining factor SRY, suggesting that this Y-encoded transcription factor could be involved in sexual dimorphism in HSCR. Among the SRY targets, the tyrosine kinase receptor RET represents the most important disease gene, whose mutations account for half of the familial and up to one-third of the sporadic forms of HSCR. RET is regulated by a distal and a proximal enhancer at its promoter, in which PAX3 and NKX2-1 are the resident transcription factors respectively. We show that the SRY-box 10 (SOX10) co-activator interacts and forms transcriptional complexes with PAX3 and NKX2-1 in a sequence-independent manner and exacerbates their respective transactivation activities on the RET promoter. SRY competitively displaces SOX10 in such transcription complexes and represses their regulatory functions on RET. Hence SRY could be a Y-located negative modifier of RET expression; and if it is ectopically expressed during ENS development, such SRY repression could result in RET protein haploinsufficiency and promotion of HSCR development, thereby contributing to sexual dimorphism in HSCR.

Silver nanoparticle treatment ameliorates biliary atresia syndrome in rhesus rotavirus inoculated mice.

Biliary atresia (BA) is a neonatal biliary system disease closely associated with viral infection and bile duct inflammation. Silver nanoparticles (AgNps) have previously revealed antiviral and anti-inflammatory properties. In this study, we have investigated the effects of AgNps in the treatment of the Rhesus rotavirus inoculation induced BA in mice. The morphology, liver histopathology, clinical biochemistry examination, and inflammatory cells were analyzed in BA mice. Results indicated that AgNps could significantly increase the survival rate of BA mice, and reduce jaundice and weight lost and the liver enzymes and bilirubin metabolism clinical parameters were close to the normal levels. Diminished numbers of NK cells were observed by flow cytometry analysis and immunohistochemical staining. Furthermore, the viral load was reduced and transcripts for TGF-ß mRNA were augmented after AgNps treatment. Collectively, our results suggest that AgNps treatment has beneficial effects on the BA mouse model partially through upregulation of TGF-ß.

Bilateral Pheochromocytomas in MEN2A Syndrome: A Two-Institution Experience.

BACKGROUND: Bilateral pheochromocytoma (PHEO) is more frequently found in patients with multiple endocrine neoplasia 2A carrying a RET germline mutation located in codon 634 (C634). However, it is unclear whether different amino acid substitutions within C634 cause differences in bilateral PHEOs expression. We aimed to answer this by pooling data from two Asian institutions. METHODS: Sixty-seven patients had confirmed C634 germline mutation. Age-dependent penetrance of bilateral PHEO was calculated from date of birth to the date when bilateral PHEO was first diagnosed or when the contralateral gland became a PHEO (if the patient already had one adrenal gland removed). Age-dependent penetrance was estimated by the Kaplan-Meier method and compared by log-rank test. RESULTS: The 4 different amino acid substitutions included C634R (arginine) (n = 19, 28.4 %), C634Y (tyrosine) (n = 36, 38.8 %), C634G (glycine) (n = 4, 6.0 %), and C634W (tryptophan) (n = 8, 11.9 %). The age-related penetrance of PHEO was similar between C634R, C634Y, C634G, and C634W (by age 40, 69.8, 55.2, 25.0, and 56.2 %, respectively) (p = 0.529). However, the age-related penetrance of bilateral PHEO in C634R was significantly higher than C634Y (by age of 40, 59.3 % vs. 25.2 %, p = 0.046) or C634Y, C634G, and C634W combined (59.3 % vs. 21.5 %, p = 0.024). Nevertheless, the accumulative risk of bilateral PHEOs across all four C634 mutations almost approached 100 % over time. CONCLUSION: The accumulative risk of bilateral PHEOs almost reached 100 % but its onset was significantly earlier in C634R mutation. These findings implied that those with C634R mutation might benefit from earlier screening of contralateral PHEO than other C634 mutations after an unilateral adrenalectomy.

Biliary-enteric reconstruction with hepaticoduodenostomy following laparoscopic excision of choledochal cyst is associated with better postoperative outcomes: a single-centre experience.

BACKGROUND: With the advent of laparoscopic surgery, more choledochal cysts are excised laparoscopically. In this study, we compared the outcomes from laparoscopic hepaticojejunostomy (HJ) and hepaticoduodenostomy (HD) for biliary-enteric reconstruction. METHODS: A retrospective analysis of patients who had undergone laparoscopic choledochal cyst excision between February 2005 and January 2014 in a tertiary referral centre was performed. Demographics data, operative techniques and surgical outcomes were analysed according to the way of biliary-enteric reconstruction. RESULTS: A total of 31 patients were identified, 20 of whom underwent HJ and 11 underwent HD. There were no significant differences in terms of demographics. Median operative time was significantly shorter in HD group (211.0 ± 96.4 vs. 386.0 ± 90.4 min, p = 0.001). Although postoperative enteral feeding was initiated later in HD group (5.0 ± 0.8 vs. 4.0 ± 3.6 days, p = 0.036), postoperative stay in intensive care unit (ICU) (0.7 ± 1.0 vs. 2.4 ± 1.7 days, p = 0.007) and overall hospital stay (9.1 ± 1.0 vs. 14.4 ± 12.2 days, p = 0.157) favoured HD group. There was no perioperative mortality. Median follow-up duration was 24.0 (±11.0) months in HD group and 67.5 (±23.7) months in HJ group. One patient in HJ group had postoperative cholangitis related to anastomotic stricture whereas no cholangitis noted in HD group. In total, five patients in HJ group required second operation for complications and residual diseases whereas none in HD group required reoperation. CONCLUSIONS: Laparoscopic excision of choledochal cyst with hepaticoduodenostomy reconstruction is safe and feasible with shorter operative time, ICU stay and overall hospital stay. It is not inferior to HJ in terms of short-term postoperative outcomes.

Use of robotic-assisted laparoscopic Mitrofanoff appendicovesicostomy in a paediatric patient: problem encountered.

This report is of robotic-assisted laparoscopic Mitrofanoff appendicovesicostomy in a 12-year-old patient with detrusor underactivity and hereditary sensory neuropathy. The whole operation was performed in 555 minutes with no open conversion. The patient experienced one episode of stomal stenosis, which required dilatation. At 3-year follow-up, the patient had both stomal and urinary continence. This is a safe and effective procedure to create a means of urinary catheterisation with avoidance of a large unsightly scar and comparable clinical outcome to an open procedure.

Childhood intussusception: 17-year experience at a tertiary referral centre in Hong Kong.

OBJECTIVES: To review all paediatric patients with intussusception over the last 17 years. DESIGN: Retrospective case series. SETTING: A tertiary centre in Hong Kong. PATIENTS: Children who presented with intussusception from January 1997 to December 2014 were reviewed. MAIN OUTCOME MEASURES: The duration of symptoms, successful treatment modalities, complication rate, and length of hospital stay were studied. RESULTS: A total of 173 children (108 male, 65 female) presented to our hospital with intussusception during the study period. Their median age at presentation was 12.5 months (range, 2 months to 16 years) and the mean duration of symptoms was 2.3 (standard deviation, 1.8) days. Vomiting was the most common symptom (76.3%) followed by abdominal pain (46.2%), per rectal bleeding or red currant jelly stool (40.5%), and a palpable abdominal mass (39.3%). Overall, 160 patients proceeded to pneumatic or hydrostatic reduction, among whom 127 (79.4%) were successful. Three (1.9%) patients had bowel perforation during the procedure. Early recurrence of intussusception occurred in four (3.1%) patients with non-operative reduction. No recurrence was reported in the operative group. The presence of a palpable abdominal mass was a risk factor for operative treatment (relative risk=2.0; 95% confidence interval, 1.8-2.2). Analysis of our results suggested that duration of symptoms did not affect the success rate of non-operative reduction. CONCLUSIONS: Non-operative reduction has a high success rate and low complication rate, but the presence of a palpable abdominal mass is a risk factor for failure. Operative intervention should not be delayed in those patients who encounter difficult or doubtful non-operative reduction.