Objective To study the acute toxicity of slow-release (poly lactic-co-glycolic acid) PLGA-gemcitabine microsphere and gemcitabine on mice.Methods Up and down procedure (UDP) was used to determine the median lethal dose (LD50) of PLGA-gemcitabine microsphere and gemcitabine on mice respectively.Results The LD50 of PLGA-gemcitabine microsphere on mice was 256.30 mg/kg,gemcitabine was 8.91 mg/kg.The difference was 28.8 times.Conclusion PLGA-gemcitabine microsphere can markedly reduce the acute toxicity of gemcitabine.

Objective To evaluate wall histological abnormalities 2 to 3 cm to the end in high or intermediate anal atresia in order to identify features that explain postoperative bowel dysfunctions.Methods Sixty anal atresia patients treated in the Capital Pediatric Institution between January 2008 and December 2012 were recruited in our study.36 patients were resected the terminal anal segment (3 cm).Compared with those 24 cases who were not.Resected samples were fixed for HE and immuno-histochemical stainings.Clinical data including sacral ratio (SR),age at operation,gender,bowel function were evaluated.Results There was no significant difference in patients' SR value,gender and age at operation between resected group and control group.The median follow-up period was 4.5 years.The rates of voluntary bowel movement,soiling (grade 1,2,3) were similar in both groups,however,the rates of severe constipation in resection group was significantly lower that in control group (3 ％ vs.21％,P ＜ 0.05) In the bowel wall of distal 2 cm anrectal canal,the connective tissue was found to be irregular and abnormally represented.Muscle coat was abnormal in all cases,showing the dysplasia circular and longitudinal layers.The number of enteric nervous system was significant fewer in distal 2cm anrectal canal than that in distal 3 cm(1.6 ±0.9 vs.5.6 ±1.8,t=11.715,P＜0.01).Conclusions Resection of terminal 3 cm at least of the atresia anal canal benefits postoperative bowel defecation function.