26
|
Tang CSM, Gui H, Kapoor A, Kim JH, Luzón-Toro B, Pelet A, Burzynski G, Lantieri F, So MT, Berrios C, Shin HD, Fernández RM, Le TL, Verheij JBGM, Matera I, Cherny SS, Nandakumar P, Cheong HS, Antiñolo G, Amiel J, Seo JM, Kim DY, Oh JT, Lyonnet S, Borrego S, Ceccherini I, Hofstra RMW, Chakravarti A, Kim HY, Sham PC, Tam PKH, Garcia-Barceló MM. Trans-ethnic meta-analysis of genome-wide association studies for Hirschsprung disease. Hum Mol Genet 2017; 25:5265-5275. [PMID: 27702942 DOI: 10.1093/hmg/ddw333] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 09/28/2016] [Indexed: 02/04/2023] Open
Abstract
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.
Collapse
|
27
|
Gui H, Schriemer D, Cheng WW, Chauhan RK, Antiňolo G, Berrios C, Bleda M, Brooks AS, Brouwer RWW, Burns AJ, Cherny SS, Dopazo J, Eggen BJL, Griseri P, Jalloh B, Le TL, Lui VCH, Luzón-Toro B, Matera I, Ngan ESW, Pelet A, Ruiz-Ferrer M, Sham PC, Shepherd IT, So MT, Sribudiani Y, Tang CSM, van den Hout MCGN, van der Linde HC, van Ham TJ, van IJcken WFJ, Verheij JBGM, Amiel J, Borrego S, Ceccherini I, Chakravarti A, Lyonnet S, Tam PKH, Garcia-Barceló MM, Hofstra RMW. Whole exome sequencing coupled with unbiased functional analysis reveals new Hirschsprung disease genes. Genome Biol 2017; 18:48. [PMID: 28274275 PMCID: PMC5343413 DOI: 10.1186/s13059-017-1174-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 02/17/2017] [Indexed: 12/17/2022] Open
Abstract
Background Hirschsprung disease (HSCR), which is congenital obstruction of the bowel, results from a failure of enteric nervous system (ENS) progenitors to migrate, proliferate, differentiate, or survive within the distal intestine. Previous studies that have searched for genes underlying HSCR have focused on ENS-related pathways and genes not fitting the current knowledge have thus often been ignored. We identify and validate novel HSCR genes using whole exome sequencing (WES), burden tests, in silico prediction, unbiased in vivo analyses of the mutated genes in zebrafish, and expression analyses in zebrafish, mouse, and human. Results We performed de novo mutation (DNM) screening on 24 HSCR trios. We identify 28 DNMs in 21 different genes. Eight of the DNMs we identified occur in RET, the main HSCR gene, and the remaining 20 DNMs reside in genes not reported in the ENS. Knockdown of all 12 genes with missense or loss-of-function DNMs showed that the orthologs of four genes (DENND3, NCLN, NUP98, and TBATA) are indispensable for ENS development in zebrafish, and these results were confirmed by CRISPR knockout. These genes are also expressed in human and mouse gut and/or ENS progenitors. Importantly, the encoded proteins are linked to neuronal processes shared by the central nervous system and the ENS. Conclusions Our data open new fields of investigation into HSCR pathology and provide novel insights into the development of the ENS. Moreover, the study demonstrates that functional analyses of genes carrying DNMs are warranted to delineate the full genetic architecture of rare complex diseases. Electronic supplementary material The online version of this article (doi:10.1186/s13059-017-1174-6) contains supplementary material, which is available to authorized users.
Collapse
|
28
|
Yeung F, Chung PHY, Hung ELY, Yuen CS, Tam PKH, Wong KKY. Surgical Intervention for Primary Spontaneous Pneumothorax in Pediatric Population: When and Why? J Laparoendosc Adv Surg Tech A 2017; 27:841-844. [PMID: 28099064 DOI: 10.1089/lap.2016.0163] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
INTRODUCTION Spontaneous pneumothorax in pediatric patients is relatively uncommon. The management strategy varies in different centers due to dearth of evidence-based pediatric guidelines. In this study, we reviewed our experience of thoracoscopic management of primary spontaneous pneumothorax (PSP) in children and identified risk factors associated with postoperative air leakage and recurrence. MATERIALS AND METHODS We performed a retrospective analysis of pediatric patients who had PSP and underwent surgical management in our institution between April 2008 and March 2015. Demographic data, radiological findings, interventions, and surgical outcomes were analyzed. RESULTS A total of 92 patients with 110 thoracoscopic surgery for PSP were identified. The indications for surgery were failed nonoperative management with persistent air leakage in 32.7%, recurrent ipsilateral pneumothorax in 36.4%, first contralateral pneumothorax in 14.5%, bilateral pneumothorax in 10%, and significant hemopneumothorax in 5.5%. Bulla was identified in 101 thoracoscopy (91.8%) with stapled bullectomy performed. 14.5% patients had persistent postoperative air leakage and treated with reinsertion of thoracostomy tube and chemical pleurodesis. 17.3% patients had postoperative recurrence occurred at mean time of 11 months. Operation within 7 days of symptoms onset was associated with less postoperative air leakage (P = .04). Bilateral pneumothorax and those with abnormal radiographic features had significantly more postoperative air leakage (P = .002, P < .01 respectively) and recurrence (P < .01, P = .007). CONCLUSION Early thoracoscopic mechanical pleurodesis and stapled bullectomy after thoracostomy tube insertion could be offered as a primary option for management of large PSP in pediatric population, since most of these patients had bulla identified as the culprit of the disease.
Collapse
|
29
|
Leung JL, Chung PHY, Tam PKH, Wong KKY. Application of anchoring stitch prevents rectal prolapse in laparoscopic assisted anorectal pullthrough. J Pediatr Surg 2016; 51:2113-2116. [PMID: 27680599 DOI: 10.1016/j.jpedsurg.2016.09.051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 09/13/2016] [Indexed: 01/31/2023]
Abstract
BACKGROUND Rectal prolapse has been reported after laparoscopic assisted anorectal pullthrough in children with anorectal malformation. We report our clinical outcome and study the application of an anchoring stitch to tack the rectum to the presacral fascia and the occurrence of rectal prolapse. MATERIAL AND METHODS A retrospective review of all children who had undergone laparoscopic assisted anorectal pullthrough for anorectal malformation from 2000 to 2015 was performed. Patients were divided into two groups (group I: with anchoring stitch, group II: without anchoring stitch). Outcome measures including rectal prolapse, soiling, voluntary bowel control, and constipation, and Kelly Score were analyzed. RESULTS There were thirty-four patients (group I, n=20; group II, n=14) undergoing laparoscopic assisted anorectal pullthrough during the study period. The median follow up duration for group I and group II was 60months and 168months, respectively. All patients had stoma performed prior to the operation. Both groups consisted of patients with high type (30% vs 57%, p=0.12) and intermediate type (70% vs 43%, p=0.12) anorectal malformation. Seven (35%) patients in group I and 3 (21%) in group II had concomitant vertebral and spinal cord pathologies (p=0.408). The mean operative time was significantly shorter in group I (193±63min vs 242±49min, p=0.048). Rectal prolapse occurred less in group I, 4 (20%) vs 9 (64%) patients in group II and was statistically significant (p=0.008). Median time to development of rectal prolapse was 7months in group I and 5months in group II (p=0.767). Mucosectomy was performed in 15% of group I and 36% of group II (p=0.171). Soiling occurred less in group I (55% vs 79%, p=0.167). Voluntary bowel control (85% vs 93%, p=0.499) and constipation (55% vs 64%, p=0.601) were comparable in both groups. 75% in group I and 71% in group II achieved a Kelly score of 5 or above (p=0.823). CONCLUSIONS Our study showed application of anchoring stitch reduces rectal prolapse and soiling in laparoscopic assisted anorectal pullthrough. Treatment Study-Level III.
Collapse
|
30
|
Wong CWY, Jin S, Chen J, Tam PKH, Wong KKY. Predictors for bowel resection and the presence of a pathological lead point for operated childhood intussusception: A multi-center study. J Pediatr Surg 2016; 51:1998-2000. [PMID: 27666006 DOI: 10.1016/j.jpedsurg.2016.09.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 09/12/2016] [Indexed: 12/16/2022]
Abstract
BACKGROUND Intussusception may require bowel resection. Here, we aim to define factors that predict the need of bowel resection and the presence of pathological lead point. METHODS A retrospective review was taken from three tertiary centers for all operated intussusception patients from January 2010 to December 2014. Patient demographics were recorded. Statistical analysis was performed, and risk factors were derived by binary logistic regression. RESULTS Five thousand ninety-six patients were treated for intussusception with 73 (57 male, 16 female) operated. The median age was 23.2months, and median duration of symptoms was 2days. Twenty-eight patients (38.4%) required bowel resection. Logistic regression demonstrated that older age (p=0.018) and longer duration of symptoms (p=0.009) were associated with bowel resection. Furthermore, older age was a predictive factor for the presence of a pathological lead point (p=0.01). A palpable abdominal mass was also found to be associated with the need of bowel resection (risk ratio 2.3) and the presence of pathological lead point (risk ratio 2.3) independently. CONCLUSION Older age at presentation and a longer duration of symptoms are positive predictors for the need of bowel resection in intussusception. The presence of a pathological lead point is more likely in older children. LEVEL OF EVIDENCE Case series with no comparison group - Level IV.
Collapse
|
31
|
Lau ECT, Fung ACH, Wong KKY, Tam PKH. Beneficial effects of mucous fistula refeeding in necrotizing enterocolitis neonates with enterostomies. J Pediatr Surg 2016; 51:1914-1916. [PMID: 27670958 DOI: 10.1016/j.jpedsurg.2016.09.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 09/12/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Necrotizing enterocolitis in premature neonates often results in bowel resection and stoma formation. One way to promote bowel adaptation before stoma closure is to introduce proximal loop effluents into the mucous fistula. In this study, we reviewed our experience with distal loop refeeding with respect to control group. METHODS All patients with necrotizing enterocolitis between 2000 and 2014 necessitating initial diverting enterostomies and subsequent stoma closure in a tertiary referral center were included. Medical records were retrospectively reviewed. Demographic data, surgical procedures, and postoperative outcomes were analyzed. RESULTS 92 patients were identified, with 77 patients receiving mucous fistula refeeding. The refeeding group showed less bowel ends size discrepancy (25 vs 53%, p=0.034) and less postoperative anastomotic leakage (3 vs 20%, p=0.029). Fewer refeeding group patients developed parenteral nutrition related cholestasis (42 vs 73%, p=0.045) and required shorter parenteral nutrition support (47 vs 135days, p=0.002). The mean peak bilirubin level was higher in the non-refeeding group (155 vs 275μmol/L, p<0.001). No major complication was associated with refeeding. CONCLUSIONS Mucous fistula refeeding is safe and can decrease risk of anastomotic complication and parental nutrition related cholestasis. It provides both diagnostic and therapeutic value preoperatively and its use should be advocated. Level III Treatment Study in a Case Control Manner.
Collapse
|
32
|
Wong CWY, Chung PHY, Tam PKH, Wong KKY. Laparoscopic versus open operation for perforated peptic ulcer in pediatric patients: A 10-year experience. J Pediatr Surg 2015; 50:2038-40. [PMID: 26386878 DOI: 10.1016/j.jpedsurg.2015.08.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 08/24/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Perforated peptic ulcer (PPU) is a relatively uncommon condition in children. We aim to evaluate and compare the outcomes of laparoscopic omental patch repair versus open repair for PPU in pediatric patients. METHODS Children who underwent omental patch repair for PPU from 2004 to 2014 in our hospital were reviewed retrospectively. Patient demographics, perioperative as well as intraoperative details and surgical outcomes, were analyzed. RESULTS Thirteen patients were identified, and all presented with abdominal pain. The median age of the study group was 14.9years (range 6.3 to 18.4years). Radiological evidence of pneumoperitoneum on erect chest x-ray (CXR) was found only in five patients (38.5%). None of the patients had a known history of peptic ulcer disease. Diagnosis other than PPU was made in five patients preoperatively. Laparoscopic repair was attempted in eight patients with one of them requiring conversion. There was no significant difference in patient demographics when compared with the open repair group. The perforation site was in the duodenum in 11 patients and in the antrum in two patients. The mean size of perforation was larger in the open repair group (p=0.005). Although the operating time was longer in the laparoscopic group (p=0.51), the length of hospital stay was significantly shorter (p=0.048). Only two patient diseases were Helicobacter pylori related. CONCLUSION Clinical features of perforated peptic ulcer in children are different from adults. Risk factors are less frequently identified. Laparoscopic omental patch repair is a feasible surgical option and is associated with satisfactory outcomes in pediatric practice.
Collapse
|
33
|
Chan IHY, Li FHQ, Lan LCL, Wong KKY, Yip PKF, Tam PKH. Use of robotic-assisted laparoscopic Mitrofanoff appendicovesicostomy in a paediatric patient: problem encountered. Hong Kong Med J 2015; 21:468-70. [PMID: 26493079 DOI: 10.12809/hkmj144340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
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.
Collapse
|
34
|
Wong CWY, Chan IHY, Chung PHY, Lan LCL, Lam WWM, Wong KKY, Tam PKH. Childhood intussusception: 17-year experience at a tertiary referral centre in Hong Kong. Hong Kong Med J 2015; 21:518-23. [PMID: 26371157 DOI: 10.12809/hkmj144456] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
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.
Collapse
|
35
|
Lang BHH, Yu HW, Lo CY, Lee KE, Garcia-Barcelo MM, Woo YC, Lee PCH, Wong KP, Tam PKH, Lam KSL. Bilateral Pheochromocytomas in MEN2A Syndrome: A Two-Institution Experience. World J Surg 2015; 39:2484-91. [DOI: 10.1007/s00268-015-3117-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
36
|
Yeung F, Chung PHY, Wong KKY, Tam PKH. Biliary-enteric reconstruction with hepaticoduodenostomy following laparoscopic excision of choledochal cyst is associated with better postoperative outcomes: a single-centre experience. Pediatr Surg Int 2015; 31:149-53. [PMID: 25433691 DOI: 10.1007/s00383-014-3648-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/25/2014] [Indexed: 12/25/2022]
Abstract
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.
Collapse
|
37
|
Wong CWY, Lau CT, Chung PHY, Lam WMW, Wong KKY, Tam PKH. The value of the 24-h delayed abdominal radiograph of barium enema in the diagnosis of Hirschsprung's disease. Pediatr Surg Int 2015; 31:11-5. [PMID: 25348880 DOI: 10.1007/s00383-014-3632-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/21/2014] [Indexed: 10/24/2022]
Abstract
AIM OF STUDY The objective of this study is to determine the diagnostic value of the 24-h delayed film for Hirschsprung's disease (HD). Other features of the barium enema were also examined, in particular the correlation between the radiological transition zone (TZ) and the final pathology. METHODS All patients with suspected HD from 2003 to 2013 who had undergone barium enema and rectal biopsy were reviewed retrospectively to study the correlation between radiological features of barium enema with the final diagnosis as well as severity. RESULTS A total of 182 patients were admitted for suspected HD during the study period, of which 82 had both investigations done. 68 patients had radiological features suggestive of the disease and ultimately, 12 patients had the disease confirmed with rectal biopsy. Among those without radiological features of HD, 2 patients were found to have the disease. Thus, the sensitivity of the 24-h delayed film was 85.7 % and the specificity was 17.6 %. The positive predictive value (PPV) of this test was 20.6 % and the negative predictive value (NPV) was 85.7 %. Regarding the level of TZ, it was not detected in the barium enema in 7 (50 %) out of the 14 patients. For those with the presence of TZ, 6 (85.7 %) of them correlated well with the intra-operative findings and 4 (57.1 %) of them correlated well with the final histology. CONCLUSION The 24-h delayed film of barium enema has a high NPV and is useful to rule out HD. However, rectal biopsy is still suggested for disease confirmation given its low PPV. Lastly, once present, the level of radiological TZ is also a useful predictor for the actual disease involvement.
Collapse
|
38
|
Li Y, Kido T, Garcia-Barcelo MM, Tam PKH, Tabatabai ZL, Lau YFC. SRY interference of normal regulation of the RET gene suggests a potential role of the Y-chromosome gene in sexual dimorphism in Hirschsprung disease. Hum Mol Genet 2014; 24:685-97. [PMID: 25267720 DOI: 10.1093/hmg/ddu488] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
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.
Collapse
|
39
|
El-Nezami H, Tam PKH, Chan Y, Lau ASY, Leung FCC, Chen SF, Lan LCL, Wang MF. Impact of melamine-tainted milk on foetal kidneys and disease development later in life. Hong Kong Med J 2013; 19 Suppl 8:34-38. [PMID: 24473527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
|
40
|
Tam PKH, Wong KKY, Li L, Zhang JZ. Internationalization: the Hong Kong-China experience as a model for collaborative education in Asia. Pediatr Surg Int 2013; 29:1053-9. [PMID: 23975023 DOI: 10.1007/s00383-013-3407-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The Hong Kong model for collaboration in education in Asia is based on internationalization. Hong Kong benefits from being an international city combining an Eastern heritage and a Western society. The University of Hong Kong ranks among the world's top 25 universities (2012/2013 QS world university rankings), and its Division of Paediatric Surgery has an international reputation in research and training. In the past two decades, Hong Kong has leading roles in major international pediatric surgical organizations including Pacific Association of Pediatric Surgeons, International Pediatric Endosurgery Group, Asian Association of Pediatric Surgeons and World Federation of Associations of Pediatric Surgeons. While Hong Kong has close collaboration with Japan and other advanced economies, the talk will focus on our transfer of international experience to Mainland China. METHODS AND RESULTS (1) A Train-the-Trainer scheme consisting of a 1-year structured education program for next-generation leaders from selected centers enabled replication and proliferation of similar training nationwide. (2) A series of laparoscopic workshops resulted in training of over 1,300 surgeons in basic and advanced skills in minimally invasive surgery within 5 years and the establishment of a national specialist organization overseeing development and quality assurance. (3) A series of Cross-Strait Symposia on Pediatric Oncology established the foundation of multidisciplinary, multicenter collaboration in education and research in Mainland China, Taiwan and Hong Kong. (4) Initiation of a scientific writing course will enhance surgical research and training in China. CONCLUSION The Hong Kong experience may serve as a model of collaboration with other developing economies in Asia.
Collapse
|
41
|
Lau CT, Leung L, Chan IHY, Chung PHY, Lan LCL, Chan KL, Wong KKY, Tam PKH. Thoracoscopic resection of congenital cystic lung lesions is associated with better post-operative outcomes. Pediatr Surg Int 2013; 29:341-5. [PMID: 23292534 DOI: 10.1007/s00383-012-3243-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION The incidence of congenital cystic lung lesions has been increasing in recent years due to better antenatal detection. With the introduction and maturation of thoracoscopy, the operative management for these lesions has seen advancement in the last decade. In this study, we aimed to compare the post-operative outcomes of patients who had thoracoscopic resection with those who underwent open resection. METHODS A retrospective review of all patients who underwent surgery for congenital cystic lung lesions between January 1996 and June 2012 in a tertiary referral center was conducted. Patients' demographics, operative procedures and post-operative outcomes were analyzed. RESULTS Sixty-seven patients were identified over the past 15 years. Thirty-nine patients had thoracoscopic resections and 28 had open resections. Thirteen patients in the thoracoscopic group required conversion. Both groups had similar demographics in terms of age, body weight and laterality of lesions. The mean operative time and blood loss in the two groups were comparable. Patients in the thoracoscopic group had significantly shorter duration of chest tube drainage (4.3 vs. 6.9 days, p = 0.004), shorter intensive care unit stay (2.5 vs. 5.9 days, p = 0.003) and shorter hospital stay (6.9 vs. 12.0 days, p < 0.001). Post-operative complication rate was similar between the two groups. Patients with body weight less than 5 kg showed a significantly higher conversion to open surgery as compared to those with body weight more than 5 kg (62.5 vs. 25.8 %, p = 0.049). CONCLUSION Successful thoracoscopic resection for congenital cystic lung lesions results in better post-operative outcomes. However, this technique remains technically challenging in patients with body weight less than 5 kg.
Collapse
|
42
|
Huang J, Tao J, Chen K, Dai K, Tao Q, Chan IHY, Chung PHY, Lan LCL, Tam PKH, Wong KKY. Thoracoscopic repair of oesophageal atresia: experience of 33 patients from two tertiary referral centres. J Pediatr Surg 2012; 47:2224-7. [PMID: 23217880 DOI: 10.1016/j.jpedsurg.2012.09.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 09/01/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND With advances in minimally invasive surgery, thoracoscopic repair of oesophageal atresia has become popular in many centres worldwide and indeed has been described as the pinnacle of neonatal surgery. Here, we report our experience in two tertiary referral centres. METHODS Thoracoscopic technique was introduced in 2007. Thus, a retrospective review of all patients diagnosed with oesophageal atresia was carried out. Patients who had thoracoscopic repair were included, and those who had open repair due to co-morbidities were excluded. Patient demographics, operative data, complications, and associated anomalies were noted. RESULTS A total of thirty-three patients underwent thoracoscopic repair during the time period. Thirty-one were successfully repaired thoracoscopically. Two patients had conversions due to intra-operative instability. The mean body weight of the neonates was 2.58 kg. The mean operative time was 146 min. Three patients suffered from minor anastomotic leaks, which healed on conservative management. Seven patients had anastomotic strictures, which responded successfully to endoscopic dilatation. Two patients died in the post-operative period due to pneumonia. One patient had a recurrent fistula 3 months after the primary repair, and he subsequently underwent a successful second repair. CONCLUSIONS In experienced hands, thoracoscopic repair of oesophageal atresia is at least as good as open surgery but with less surgical trauma. Standard of post-operative care contributes significantly to post-operative outcome. Thoracoscopic technique is now our preferred approach.
Collapse
|
43
|
Li D, Tsang JYS, Peng J, Ho DHH, Chan YK, Zhu J, Lui VCH, Xu A, Lamb JR, Tam PKH, Chen Y. Adiponectin mediated MHC class II mismatched cardiac graft rejection in mice is IL-4 dependent. PLoS One 2012; 7:e48893. [PMID: 23155424 PMCID: PMC3498365 DOI: 10.1371/journal.pone.0048893] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/03/2012] [Indexed: 11/18/2022] Open
Abstract
Background Adiponectin regulates glucose and fatty-acid metabolism but its role in chronic graft rejection mediated by Th2 cytokines remains ill-defined. Methodology/Principal Findings Wild type and adiponectin-null mice were used as graft recipients in mouse MHC class II disparate cardiac transplantation (bm12 toB6) and the graft rejection was monitored. In adiponectin-null mice we observed that the cellular infiltrate of eosinophils, CD4+ and CD8+ T cells was reduced in grafts compared to the controls as was collagen deposition and vessel occlusion. A similar outcome was observed for skin transplants except that neutrophil infiltration was increased. Low levels of IL-4 were detected in the grafts and serum. The effect of adiponectin signaling on IL-4 expression was further investigated. Treatment with AMPK and p38 MAPK inhibitors blocked adiponectin enhanced T cell proliferation in mixed lymphocyte reactions. Inhibition of AMPK reduced eosinophil infiltration in skin grafts in wild type recipients and in contrast AMPK activation increased eosinophils in adiponectin-null recipients. The addition of adiponectin increased IL-4 production by the T cell line EL4 with augmented nuclear GATA-3 and phospho-STAT6 expression which were suppressed by knockdown of adiponectin receptor 1 and 2. Conclusions Our results demonstrate a direct effect of adiponectin on IL-4 expression which contributes to Th2 cytokine mediated rejection in mouse MHC class II histoincompatible transplants. These results add to our understanding of the interrelationship of metabolism and immune regulation and raise the possibility that AMPK inhibitors may be beneficial in selected types of rejection.
Collapse
|
44
|
Chung PHY, Wong KKY, Lan LCL, Tam PKH. Peanut aspiration: an avoidable life-threatening condition. Hong Kong Med J 2012; 18:340-342. [PMID: 22865181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023] Open
Abstract
Foreign body aspiration is a potentially fatal condition. Yet, an accurate diagnosis may not be easy. Management is also challenging and requires a high level of expertise with proper instruments. In this article, we report our experience in the management of peanut aspiration in two young children by means of a ventilating bronchoscope.
Collapse
|
45
|
Chok KSH, Chan SC, Chan KL, Sharr WW, Tam PKH, Fan ST, Lo CM. Bile duct anastomotic stricture after pediatric living donor liver transplantation. J Pediatr Surg 2012; 47:1399-403. [PMID: 22813803 DOI: 10.1016/j.jpedsurg.2011.12.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 11/08/2011] [Accepted: 12/12/2011] [Indexed: 12/25/2022]
Abstract
BACKGROUND/PURPOSE Hepaticojejunostomy is a well-accepted method, whereas duct-to-duct anastomosis is gaining popularity for bile duct reconstruction in pediatric living donor liver transplantation (LDLT). Biliary complications, especially biliary anastomotic stricture (BAS), are not clearly defined. The aim of the present study is to determine the rate of BAS and its associated risk factors. METHODS The study included 78 pediatric patients (<18 years old) who underwent LDLT during the period from end of September 1993 to end of November 2010. The diagnosis of BAS was based on clinical, biochemical, histologic, and radiologic results. RESULTS All patients received left-side grafts. Thirteen patients (16.7%) developed BAS after LDLT. Among them, 3 patients (23.1%) had duct-to-duct anastomosis during LDLT. The median follow-up period for the BAS group and the non-BAS group was 57.8 and 79.5 months, respectively (P = .683). Ten of the patients with BAS required percutaneous transhepatic biliary drainage with or without dilatation for treating the stricture. Multivariable analysis showed that hepatic artery thrombosis and duct-to-duct anastomosis were 2 risk factors associated with BAS. CONCLUSION In pediatric LDLT, hepaticojejunostomy is the preferred method for bile duct reconstruction, but more large-scale research needs to be done to reconfirm this result.
Collapse
|
46
|
Hao W, Chan IHY, Liu X, Tang PMY, Tam PKH, Wong KKY. Early post-operative interleukin-6 and tumor necrosis factor-α levels after single-port laparoscopic varicocelectomy in children. Pediatr Surg Int 2012; 28:281-6. [PMID: 21994078 PMCID: PMC3284665 DOI: 10.1007/s00383-011-3011-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/03/2011] [Indexed: 12/21/2022]
Abstract
PURPOSE Laparoendoscopic single-site surgery has recently been described in children and regarded as an improved technology leading to less pain and better cosmetic outcome. Compared to the traditional three-port method, it is not known if the single-port method is less invasive. The aim of this study was thus to investigate the post-operative acute inflammatory response in order to evaluate surgical stress in the two surgical approaches in children. METHODS A prospective, single blinded, case-control study was carried out. Thirteen male patients who presented with unilateral varicocele were divided into two groups. Six children underwent single-port laparoscopic procedure, while the other seven children underwent three-port laparoscopic procedure. Pre-operative and post-operative blood samples were taken for the measurement of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) using ELISA. Demographics including the operation time, and complications were recorded. Data between the two groups were analyzed using unpaired t-test and a p value of <0.05 was taken as statistically significant. RESULTS The mean age of patients was 14.5 years (range 12-19 years). There was no significant difference between the two groups in terms of operative time, nor there was any complication recorded. The change in serum TNF-α and IL-6 concentrations pre- and post-operatively between the single-port group and three-port group was not statistically significant. Overall, patients in the two groups showed excellent satisfaction in terms of post-operative cosmesis. CONCLUSION Single-port laparoscopic varicocelectomy is safe, effective and produces excellent cosmesis with minimal surgical stress.
Collapse
|
47
|
Zhou M, Xu A, Tam PKH, Lam KSL, Huang B, Liang Y, Lee IK, Wu D, Wang Y. Upregulation of UCP2 by adiponectin: the involvement of mitochondrial superoxide and hnRNP K. PLoS One 2012; 7:e32349. [PMID: 22359684 PMCID: PMC3281141 DOI: 10.1371/journal.pone.0032349] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 01/26/2012] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The adipocyte-derived hormone adiponectin elicits protective functions against fatty liver diseases and hepatic injuries at least in part by stimulating the expression of a mitochondrial inner membrane transporter, uncoupling protein 2 (UCP2). The present study was designed to investigate the cellular and molecular mechanisms underlying adiponectin-induced UCP2 expression. METHODOLOGY/PRINCIPAL FINDINGS Mice were treated with adiponectin and/or different drug inhibitors. Parenchymal (PCs) and nonparenchymal (NPCs) cells were fractionated from the liver tissues for mitochondria isolation, Western blotting and quantitative PCR analysis. Mitochondrial superoxide production was monitored by MitoSOX staining and flow cytometry analysis. Compared to control mice, the expression of UCP2 was significantly lower in NPCs, but not PCs of adiponectin knockout mice (AKO). Both chronic and acute treatment with adiponectin selectively increased the mRNA and protein abundance of UCP2 in NPCs, especially in the enriched endothelial cell fractions. The transcription inhibitor actinomycin D could not block adiponectin-induced UCP2 expression, whereas the protein synthesis inhibitor cycloheximide inhibited the elevation of UCP2 protein but not its mRNA levels. Mitochondrial content of heterogeneous nuclear ribonucleoprotein K (hnRNP K), a nucleic acid binding protein involved in regulating mRNA transportation and stabilization, was significantly enhanced by adiponectin, which also evoked a transient elevation of mitochondrial superoxide. Rotenone, an inhibitor of mitochondrial respiratory complex I, abolished adiponectin-induced superoxide production, hnRNP K recruitment and UCP2 expression. CONCLUSIONS/SIGNIFICANCE Mitochondrial superoxide production stimulated by adiponectin serves as a trigger to initiate the translocation of hnRNP K, which in turn promotes UCP2 expressions in liver.
Collapse
|
48
|
Wong KKY, Wu X, Chan IHY, Tam PKH. Evaluation of defecative function 5 years or longer after laparoscopic-assisted pull-through for imperforate anus. J Pediatr Surg 2011; 46:2313-5. [PMID: 22152872 DOI: 10.1016/j.jpedsurg.2011.09.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 09/03/2011] [Indexed: 11/24/2022]
Abstract
BACKGROUND Laparoscopic anorectoplasty was introduced in 2000, but the procedure has not yet gained universal acceptance. Previous studies, including ours, reported satisfactory early postoperative outcome as compared with posterior sagittal anorectoplasty (PSARP), but mid- to long-term results are not available. Here, we aim to evaluate the mid- to long-term defecative function in these patients. MATERIALS AND METHODS A retrospective study was carried out and included all patients who underwent laparoscopic-assisted anorectoplasty for high-/intermediate-type imperforate anus between 2001 and 2005. Their degree of continence was graded according to the Krickenbeck classification and compared with historical controls treated with PSARP. The results were compared using χ(2) test, and P < .05 was considered statistically significant. RESULTS There were 18 patients who underwent laparoscopic anorectoplasty (LAR) in the study period. They were compared with 20 historical PSARP patients. For defecation sensation, 16 of the 18 LAR patients were positive, whereas there were 16 of 20 PSARP patients. Eight LAR patients were clean without any fecal soiling or incontinence (11/20 PSARP). Only 3 of 18 LAR had constipation as compared with 7 of 20 PSARP. The need for rectal enema for evacuation was seen in 1 of 20 LAR patients and 2 of 20 PSARP patients (for all categories, P > .05). CONCLUSIONS Mid- to long-term follow-up study revealed satisfactory defecative function for patients with high-/intermediate-type imperforate anus after LAR. The outcome is at least as good as PSARP. Longer term follow-up with larger sample size is necessary to demonstrate the benefits of LAR over PSARP.
Collapse
|
49
|
Leon TYY, So MT, Lui VCH, Hofstra RMW, Tam PKH, Ngan ESW, Garcia-Barceló MM. Functional analyses of RET mutations in Chinese Hirschsprung disease patients. ACTA ACUST UNITED AC 2011; 94:47-51. [PMID: 22131258 DOI: 10.1002/bdra.22863] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 08/17/2011] [Accepted: 08/25/2011] [Indexed: 01/29/2023]
Abstract
BACKGROUND Hirschsprung disease (HSCR) is a congenital disease characterized by the absence of ganglion cells in various length of distal digestive tract. The rearranged during transfection gene (RET) is considered the major gene in HSCR. Although an increasing number of HSCR-associated RET coding sequence (CDS) mutations have been identified in recent years, not many have been investigated for functional consequence on the RET protein. METHODS AND RESULTS We examined the functional implications of the de novo RET-CDS mutations V145G, Y483X, V636fsX1, and F961L that we first identified in sporadic Chinese patients with HSCR. The V145G disrupted RET glycosylation and F961L RET phosphorylation. Presumably, the truncation mutations would affect the translocation or the anchoring of the RET protein onto the cellular membrane. CONCLUSION The study of RET-CDS mutations that appear de novo is essential not only for understanding the mechanistic of the disease but also for penetrance and recurrence risk estimations, being the ultimate goal for the improvement in disease management and counseling.
Collapse
|
50
|
Tsang JYS, Ratnasothy K, Li D, Chen Y, Bucy RP, Lau KF, Smyth L, Lombardi G, Lechler R, Tam PKH. The potency of allospecific Tregs cells appears to correlate with T cell receptor functional avidity. Am J Transplant 2011; 11:1610-20. [PMID: 21797973 DOI: 10.1111/j.1600-6143.2011.03650.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
CD4(+) CD25(+) regulatory T cells (T(reg) cells) are an attractive adoptive cell therapy in mediating transplantation tolerance. T-cell receptor (TcR) activation is critical for T(reg) function, suggesting that the TcR avidity of T(reg) cells used in therapy may affect the therapeutic outcome. To address this, we compared the regulatory capacity of T(reg) lines expressing TcRs derived from two TcR transgenic mice shown to have the same specificity but different functional avidities. T(reg) lines generated from CD4(+)CD25(+) T cells from C57BL/6 mice were transduced with one of either of these TcRs. The antigen specificity of the transduced T(reg) lines was confirmed in vitro. T(reg) lines expressing the TcR with higher functional avidity showed stronger suppressive capacity in a linked suppression model in vitro. Furthermore, the same T(reg) lines demonstrated a stronger proliferation in vivo following antigen exposure. Pretreatment of recipient BL/6 mice with these T(reg) cells, together with anti-CD8 antibody and Rapamycin therapies, prolonged survival of BALB/c skins, as compared with mice that received T(reg) lines with lower TcR avidity. Taken together, these data suggest that the TcR functional avidity may be important for T(reg) function. It highlights the fact that strategies to select T(reg) with higher functional avidity might be beneficial for immunotherapy in transplantation.
Collapse
|