Objective The aim of this study was to investigate how different concentrations of dextran sulfate sodi-um ( DSS) influence the establishment of mouse model of inflammatory bowel disease ( IBD) and the effect of DSS on the expression of colitis-associated immune factors.Methods The DSS solution in different concentrations (3%, 5%, 7%) were given to male C57BL/6J mice to generate mouse inflammatory bowel disease model.The IBD mice were observed by defecation characteristics, body weight, and survival time.The animals were sacrificed at 6 days after the start of DSS drinking.The general appearance of colons was observed and scored.Moreover, the pathological changes of the colon were examined and analyzed by routine histology.The expression of immune factors in the spleen was detected by real-time PCR.Results The mice in the 3%, 5%, 7% DSS groups developed murine colitis.In addition, the incidence of IBD and mouse mortality rate was directly proportional to the increase of DSS concentration.Furthermore, the higher concentra-tion of DSS induced the expression of proinflammatory factors including TNF-α, IFN-γand IL-17A, but cause a decrease of anti-inflammatory factors such as IL-4, IL-10 and Treg-related transcription factor Foxp3.Conclusions Our data suggest that giving 5%DSS solution to C57BL/6J mouse is appropriate to efficiently establish a murine IBD model.This laid an important foundation for further studies of the pathogenesis of IBD, biological characteristics, and intervention factors.

Objective To evaluate the change of clinicopathological features and prognosis of papillary thyroid cancer over a 15-year period.Methods The clinicopathological features and outcomes of papillary thyroid cancer patients were analyzed in three groups according to the time of diagnosis:group Ⅰ (1997-2001),group Ⅱ (2002-2006),and group Ⅲ (2007-2011).Results As time advanced,the average age of papillary thyroid cancer patients increased,tumor stage,like size,extrathyroid invasion and lymph node metastasis decreased dramatically (P ＜ 0.01).The percentage of multifocality and bilaterality increased.The long-term follow up data (median follow up time was 6.6 years),indicated that the 15-year over all survival was 97.8％ and the 15-year disease-free survival was 90.2％.Tumor ≥3 cm,bilaterality,extrathyroid invasion,lymph node metastasis and AJCC stage were correlated with tumor recurrence.By multivariate COX-regression analysis only lymph node metastasis and bilaterality were independent risk factors.Conclusion The clinicopathological features of papillary thyroid cancer changed over 15 years,with the percentage of early-staged patients increased.Lymph node metastasis and bilaterality are two risk factors for tumor recurrence.