Hirschsprung′s disease( HD) ,caused by the dysplasia of enteric neural crest cells during em-bryonic stage,is a multifactorial disorder with several genes or gene signaling pathways involved in its pathogen-esis. To date,at least 11 genes have been found to be associated with the pathogenesis of HD. The abnormal expression or interaction of these genes may lead to the displasia of neural crest cells,which may result in HD. Current knowledge of the molecular genetics underlying HD based on human and animal studies are reviewed.

Objective To investigate the short-term acute rejection incidence of the recipients under the steroid-free immunosuppressive therapy after liver transplantation. Methods This retrospective study included 186 patients who were divided into two groups by random number table.The patients in no steroid group (the study group, n =94) received tacrolimus (Tac) with mycophemolate mofetil (MMF) or cyclosporine with MMF,and those in the steroid group (the control group,n =92) received the aforementioned immunosuppressive therapy combined with steroids.The acute rejection incidence was analyzed during six months post-transplantation.Results There was no significant difference in the gender,age,indication for transplantation,Child-Pugh score,MELD score,operating time,bleeding and transfusion volume during the operation,warm ischemia time and cold ischemia time between the two groups (P＞0.05).Liver biopsy was done on 9 cases of each group.The acute rejection incidence had no significant difference between the study group and the control group (5/94 vs 4/92,5.3％ vs 4.4％,P＞0.05).Conclusion The steroid-free immunosuppressive therapy after liver transplantation did not increase the short term acute rejection incidence.

Objective To explore the surgical intervention outcomes of necrotizing enterocolitis (NEC)pa-tients with different extent of the disease.Methods The data of 25 pediatric patients with NEC who were treated with surgical intervention in Shanghai Children′s Hospital from December 201 1 to December 201 5 were retrospectively ana-lyzed.According to the extent of the disease,the patients were divided into 3 groups:focal disease(F),multisegmental disease(M),and pan -involvement(P).The information including operation style,survival rate and time for close osto-my was analyzed.Results There were 1 1 cases with F,8 cases with M,and 6 cases with P.All patients received lapa-rotomy surgery,colostomy,or peritoneal drainage.There were 1 2 patients with very low birth weight,7 patients with low birth weight,6 patients with normal birth weight in this study.There were 1 7 cases with gastrointestinal perforation (9 cases with pneumoperitoneum,8 cases without pneumoperitoneum),8 cases without digestive tract perforation (4 cases without pneumoperitoneum,4 cases with enterostenosis after conservative treatment).In this study,close ostomy was commonly conducted 3 -6 months after the operation,except for 3 cases who received 2 or more times of operation.The survival rate in F group was 1 00.0%(1 1 /1 1 cases),higher than those in the Mgroup with 62.5%(5 /8 cases)and P group with 1 6.7%(1 /6 cases)(χ2 =4.898,1 0.31 2,all P <0.05).However,there was no difference between Mgroup and P group (χ2 =1 .367,P >0.05).Conclusions The extent of disease is correlated to the outcomes of surgical in-tervention,as F had a better outcome than Mand P.Low birth weight is a risk factor for NEC.Protecting the edge of the bowel is a key factor to ensure the survival and improve the quality of life of NEC patients.Close ostomy should be con-sidered when the patients are in a stable condition (liver function and intestinal function recovery,good nutrition condi-tion,etc),and under special circumstances to conduct early or delayed closure of fistula.

Objective To evaluate the efficacy of living donor liver transplantation in the treatment of infants with end-stage liver diseases. Methods The clinical data of 33 infants who received living donor liver transplantation at the Renji Hospital of Shanghai Jiaotong University from October 2006 to September 2009 were retrospectively analyzed. The median age of the infants was 10.9 months, and the mean body weight was 8.2 kg.All of the grafts were left lateral lobes. Tacrolimus (or cyclosporine A) + steroid or tacrolimus (or cyclosporine A)+ steroid + mycophenolate mofeti] were applied to the infants to suppress the immune reaction. Operative techniques, perioperative management and results of follow-up were analyzed. Results The mean operation time,blood loss and blood transfusion of the donors were (384±108)minutes, (183±35) ml and O, and the three indexes of the recipients were (500± 103) minutes, (296±163) ml and (292 ± 159) ml , respectively. The cold preservation time of the grafts was (64 ±23)minutes, the mean weight of the grafts was (249 ±52)g, and the mean graft to recipient weight ratio was 2.1% ± 0.4%. All donors recovered smoothly and no complication occurred. Of the recipients, three were complicated with hepatic artery thrombosis, two with portal vein thrombosis,nine with biliary complications, 11 with infection, two with acute rejection and five infants died perioperatively.The one-year cumulative survival rate of the infants was 85% (28/33). Conclusions Infants with end-stage liver diseases could be treated by living donor liver transplantation. The development of surgical techniques and perioperative managements improves the success rate of operation and the long-term survival rate.

Objective To compare the metabolic characteristics, dosages and blood concentrations of tacrolimus (Tac) in patients subject to cadaveric liver transplantation (CLT) vs living-donor partial liver transplantation (LDLT) in order to investigate the usage of Tac in patients undergoing LDLT. Methods The clinical data of 85 patients undergoing liver transplantation from April 2007 to September 2009 were analyzed retrospectively. Thirty-four underwent LDLT (group A)and the remaining 51 underwent CLT (group B). Results The time to reach therapeutic window was shorter in group A (3. 4 ± 1.0 days) than in group B (4. 5 ± 2. 0 days, P = 0. 002). The Tac dosage in group A was significantly less than in group B during the first 28 days post-transplantation. However,the Tac dosage approached gradually and tended to be consistent after 28 days. On the postoperative day7, 14, 21 and 28 days, the Tac dosage in group A was 72.74 ％, 82.26 ％, 83.92 ％ and 88. 87 ％ of that in group B respectively. Correlation analysis revealed that graft-recipient body weight ratio (GR/WR) was significantly correlated with the Tac dosage on the day 7 (mg·day-1 · kg-1) (r =0. 728, P＜0. 01) and Tac concentration/dosage ratio (ng/ml)/(mg/kg) (r = - 0. 644, P＜0. 01 ).Conclusion The early Tac dosages in patients subject to LDLT were correlated significantly with the volume of graft. The early Tac dosages in patients undergoing LDLT were about 70 ％ of those in patients undergoing cadaveric liver transplantation. Moreover, with the regeneration of the liver, they tended to be consistent after 28 days.

Objective To characterize the clinical course of biliary complications after right lobe living donor liver transplantation (RL-LDLT) and to identify the independent risk factors for biliary strictures.Methods 105 consecutive RL-LDLT recipients operated from April 2007 to April 2010 were followed up. The clinical and operative data were reviewed. The biliary complications and independent risk factors of biliary stricture were studied.Results The median follow-up duration was 49.5 months ranging from 562 to 1675 days.A total of 40 patients (38.1 ％) experienced 11 bile leak episodes (10.4％ ) and 37 (35.2％) biliary stricture episodes after transplantation.Bile leaks occurred at a median time of 9 days ranging from 4 to 54 days after transplantation.For biliary strictures,the occurring time was delayed and scattered wide with a median of 7.6 months ranging from 12 to 790 days after transplantation. Moreover, the biliary stricture incidence in the first year after transplantation was significantly higher than later.The independent risk factors for biliary strictures were CMV infection,bile leaks and bile duct size (≤3 mm).Conclusion The independent risk factors for biliary strictures after RL-LDLT were CMV infection,bile leaks and bile duct size (≤3mm).In order to avoid biliary complications,careful preoperative evaluations are necessary. The dissection of bile ducts should be meticulous to protect its blood supply.CMV infection should be prevented after transplantation.Close surveillance of biliary complications should be given to RL-LDLT recipients during the first year after transplantation.

ObjectiveTo surnmarize the experience of tacrolimus or cyclosporine A-based immunosuppression after pediatric living-donor liver transplamation.Methods The clinical data of 30 children undergoing living-donor liver trarsplantation from October 2006 to January 2010 were analyzed retrospectively.In 30 patients,7 were given Tac-based immunosuppression (group A),10 given CsA-based immunosuppression (group B),and 13 switched from CsA to Tac for complications or adverse effects of drugs.Dosages and blood concentrations of immunosuppressants were recorded.Changes of liver and kidney functions were monitored.Incidence of rejection,infection and adverse effects of drugs were observed.ResultsIn the premise of the stable concentration and liver and kidney functions,the weight of children was increased by about 50％ and the per- kilogram dosage of CNIs was decreased significantly 1year postoperatively.There was no case of rejection in group A and 4 cases of rejection in group B(40％,4/10),and the original symptoms were gradually alleviated after the increased dosage in immunosuppressants.During the first 3 months,there was 1case of abdominal infection in group A (1/7) and 3 cases of lung infection in group B (3/10),and the original symptoms were gradually alleviated after anti-infective therapy.There was 1CMV lgM-positive case in group A (1/7) and 2 CMV IgM-positive cases in group B (2/10),and the original symptoms were gradually alleviated after using ganciclovir.The original symptoms of the 13 children switched from CsA to Tac were gradually alleviated.ConclusionThe two CNIs can be safely used in children undergoing pediatric livlng-donor liver transplantation.Both of them show the same effect in promoting the restoration of liver and kidney functions,but tacrolimus has more satisfactory effect in inhibiting the rejection and it has leas adverse effects.

Objective To observe the outcomes of living donor liver transplantation (LDLT) for children with biliary atresia (BA) and to summarize the clinical experiences. Methods Forty-four BA patients (26 boys and 18 girls) underwent LDLT between October 2006 and December 2010. Mean (SD) and median (range) age at operation was (12.1 ± 9.0) months and 9 (6-60) months,respectively. The 44 donors were lineal relatives to the consorted recipients. Their mean (SD) and median (range) age at operation was (32. 7 ± 8. 0) months and 31 (20～54) years, respectively. All donor graft types were the left lateral segments with compatible ABO blood groups. Clinical data,including pre-operative evaluations, surgical technique, postoperative management and outcomes in all donors and recipients were retrospectively analyzed. Results All donors were followed up for (17. 5 ± 13. 3) months. No donor mortality was encountered, with a minimal morbidity and no long-term sequelae. Nine out of 44 recipients died. Three patients died of portal vein thrombosis (PVT), one of hepatic artery thrombosis (HAT), two of biliary complications, one of surgical site infections, one of abdominal bleeding and one of pulmonary infection. The overall 1-year and 2-year cumulative survival rate in recipients was 81. 2% and 76. 1 %, respectively. No re-transplantation was done. Postoperative complications included PVT, HAT, biliary leakage and refluxing cholangitis, pulmonary infections,surgical site infections and acute rejection. Conclusion LDLT has been the effective treatment for pediatric recipients with BA and provides favorable prognosis. To improve prognosis of recipients, the key points are pre-operative evaluations, surgical technique, and postoperative management

Objective To explore the value of pediatric end-stage liver disease (PELD)score system in predicting prognosis after pediatric living donor liver transplantation (LDLT). Methods Clinical data of 101 infants undergoing living-donor liver transplantation from October 2006 to December 2012 in Department of Liver Surgery in Affiliated Renji Hospital of School of Medicine of Shanghai Jiaotong University,were analyzed retrospectively. All infants were diagnosed as biliary atresia. PELD scores before LDLT were graded. According to PELD scores,all the patients were divided into two groups:low score group (PELD score <16,n=62) and high score group (PELD≥16,n =39 ).The basic data during perioperative period and incidence of postoperative complications were compared between two groups. Results There were significant differences in age and body weight between two groups (both in P<0.05 ). But there was no significant difference between the two groups in gender,graft to recipient weight ratio (GRWR),cold isehemia time and intraoperative blood loss (all in P>0.05 ). The incidence of lung infection and biliary complications in high score group were significantly higher than those in low score group. Conclusions Preoperative PELD score can be used in predicting prognosis after pediatric LDLT and provide a reference for the treatment,caring and nursing during perioperative period of pediatric LDLT. For infants with high PELD score before operation,the care of perioperative complications should be enhanced.