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 analyse the change of serum Mullerian Inhibiting Substance (MIS) level and it's relation with abnormalities of urogenital system in Children. Methods The serum MIS and/or testosterone (T) values in boys and girls suffered from non-urogenital diseases, and patients who suffered cryptorchidism were measured. Results ⑴The MIS values in boys with non-urogenital diseases gradually declined from 1 to 14 years old, the mean values of 1 years old were 797 03?246 12pmol/l, and that of 14 years old were 81 74?38 40pmol/l. ⑵The T values were low before puberty (P0 05), and had significant difference from 12～14 years old (P0 05). But MIS values had significant difference between boys' and girls' (P

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 enhance awareness of the dangerous of multiple magnets ingestion in children and to explore the optimal treatment of it.Methods The clinical data of 3 cases with multiple magnet ingestion were retrospectively studied based on literature review.Results Ingestion of multiple magnets (range:2-5 magnets) magnets occurred in 3 cases.Age ranged from 1 to 8 years old.Magnet sources included:2 from children's family,1 from their kindergarten.All patients had several bowel perforations(range:2-4).One case was completed by laparoscopic,1 case was converted to open suegery after laparoscopy,1 case was done by open surgery.All cases got complete recovery after surgical treatment,and no complications occurred by follow-up.Conclusions Ingestion of multiple magnets may show minimal initial physical manifestations at beginning but may result in significant complications later.Two or more magnets separated from each other along the gastrointestinal tract can attract each other across bowel walls,with may result in pressure necrosis,bowel perforation,and fistulas formation and even death.Early surgical consultation with an aggressive surgical approach is recommended.Family and society should be aware of the dangers of magnet ingestion.

Efficient mucosal delivery remains a major challenge for the reason of the respiratory tract mucus act as a formidable barrier to nanocarriers by trapping and clearing foreign particulates. The surface property of nanoparticles determines their retention and penetration ability within the respiratory tract mucus. However, the interaction between nanoparticles and mucus, and how these interactions impact distribution has not been extensively investigated. In this study, polymeric nanoparticles loaded with a baicalein-phospholipid complex were modified with two kinds of polymers, mucoadhesive and mucus-penetrative polymer. Systematic investigations on the physicochemical property, mucus penetration, transepithelial transport, and tissue distribution were performed to evaluate the interaction of nanoparticles with the respiratory tract. Both nanoparticles had a similar particle size and good biocompatibility, exhibited a sustained-release profile, but showed a considerable difference in zeta potential. Interestingly, mucus-penetrative nanoparticles exhibited a higher diffusion rate in mucus, deeper penetration across the mucus layer, enhanced cellular uptake, increased drug distribution in airways, and superior local distribution and bioavailability as compared to mucoadhesive nanoparticles. These results indicate the potential of mucus-penetrative nanoparticles in design of a rational delivery system to improve the efficiency of inhaled therapy by promoting mucus penetration and increasing local distribution and bioavailability.