0.05). Conclusions The expression of XAF1 decreases in both malignant and benign colo-rectal tumors and is significantly lower in colorectal carcinomas than in adenomas/polyps. Thus, XAF1 may have the potential role in differentiating colorectal cancer from benign tumors.

Objective To evaluate the diagnostic efficiency of double-balloon enteroscopy in small bowel Crohn’s disease. Methods In sixty five patients with suspected small bowel Crohn's disease double-balloon enteroscopy were performed, and some of them received enteroscopy and enteroclysis, capsule endoscopy as well.Results The first enteroscopy was performed via mouth in 20 of 65 cases, and the lesions were detected in 11 cases (55%), 5 of 9 cases(55.6%) had lesions detected in enteroscopy via anus while nothing was found in mouth route. Among 45 cases examed by enteroscopy firstly via anus, 34 cases had lesions detected (75.6%), 8 of 11 cases(72.7%) had lesions found in following exam via mouth. Totally 58of 65 had lesions detected through enterosocpy examination, the overall diagnostic yield was 89.2%. Twenty four of 46 cases had positive findings with enteroclysis. The diagnosis of Crohn's disease was comfirmed in 14 of 22 patients(63.6%) underwent capsule endoscoy. The diagnosis was finally confirmed by enteroscopy only in 11 patients(78.6%).Conclusion The entire small intestine could be examined by enteroscopy with combination of mouth and anus route. Double-balloon enteroscopy was an ideal diagnostic modality for small bowel Crohn's diseases, which was also valuable in assessment on extent and severity of the disease. Small bowel enteroclysis was a useful screening alternative for selecting procedure route in DBE.

Objective: To investigate the effect of microRNAs (miR)-21 on the expression of interleukin (IL)-10 in B cell of patients with Henoch-Schonlein purpura (HSP). Methods: From March 2016 to January 2017, twenty-four children with HSP hospitalized in rheumatology and immunology department of Shenzhen Children′s Hospital were enrolled into the study, including 12 males and 12 females. Patients were divided into purpura nephritis group (HSPN, 14 cases) and non-nephritis group (NHSPN, 10 cases). The age-matched 34 healthy children were included as the control group for prospective cohort study. The expression levels of IL-10 in peripheral blood B cells (CD19⁺), transitional B cells (CD19⁺ CD24^hiCD38^hi) and naïve B cells (CD19⁺CD24^intCD38^int) from patients with HSP and healthy children were detected by flow cytometry (FCM). Expression of microRNAs related to IL-10 in B cells were quantitated by real-time PCR, including miR-21-5p, miR-106a-5p, miR-98-3p, miR-142-3p, miR-142-5p, miR-98-5p, miR-155-5p and miR-let7b-5p. Agomir negative control-FAM and agomir-21-5p-FAM were transfected into B cells from patients with HSP. The uptake of miRNA by B cells was observed by laser scanning confocal microscope and FCM, and the expression of IL-10 was detected by FCM after transfection. For quantitative data of normal distribution, t test was used for two samples comparison and multiple comparisons among three groups were conducted by ANOVA. Spearman test was used for correlation analysis. Results: (1) The CD19⁺ B cells and its two populations at different differentiation stages all could express IL-10. The expression levels of IL-10 in three B cell populations in patients were significantly lower than those in healthy controls (1.4±0.2 vs. 2.4±0.3, t=3.501, P<0.01; 1.2±0.2 vs. 2.2±0.3, t=2.688, P<0.05; 1.6±0.3 vs. 2.7±0.4, t=2.498, P<0.05). Compared with healthy control and NHSPN groups, the expression of IL-10 in CD19⁺ B cells from patients within HSPN group was the lowest, and the difference was statistically significant (1.1±0.2 vs. 2.4±0.3, 1.8±0.3, t=4.006, 2.362, P<0.001, P<0.05). (2) The expression of miR-21-5p in B cell in patients with HSPN was lower than that in healthy control group (1.2±0.9 vs. 3.5±2.8, t=2.962, P<0.01). There was no significant change in the other microRNAs. (3) The expression of IL-10 was positively correlated with the expression of miR-21-5p in the B cells of patients with HSP (r=0.778, P<0.001). (4) The expression of IL-10 in B cells of miR-21-5p group was significantly higher than that in negative control group (2.7±0.2 vs. 1.6±0.3, t=3.091, P<0.05). Conclusion The insufficient expression of miR-21-5p in peripheral blood B cells of patients with HSP is one of the reasons for the reduction of IL-10 expression in B cells.