[The effect of Helicobacter pylori infection on duodenal bulbar microbiota in children with duodenal ulcer].

Objective: To investigate the characteristics of duodenal bulbar microbiota in children with duodenal ulcer and Helicobacter pylori (Hp) infection. Methods: This prospective cohort study enrolled 23 children with duodenal ulcers diagnosed by gastroscopy who were admitted to the Children's Hospital of Zhejiang University School of Medicine due to abdominal pain, abdominal distension, and vomiting from January 2018 to August 2018. They were divided into Hp-positive and Hp-negative groups according to the presence or absence of Hp infection. Duodenal bulbar mucosa was sampled to detect the bacterial DNA by high-throughput sequencing. The statistical difference in α diversity and ß diversity, and the relative abundance in taxonomic level between the two groups were compared. Microbial functions were predicted using the software PICRUSt. T-test, Rank sum test or χ2 test were used for comparison between the two groups. Results: A total of 23 children diagnosed with duodenal ulcer were enrolled in this study, including 15 cases with Hp infection ((11.2±3.3) years of age, 11 males and 4 females) and 8 cases without Hp infection ((10.1±4.4) years of age, 6 males and 2 females). Compared with Hp-negative group, the Hp-positive group had higher Helicobacter abundance (0.551% (0.258%, 5.368%) vs. 0.143% (0.039%, 0.762%), Z=2.00, P=0.045) and lower abundance of Fusobacterium, Streptococcus and unclassified- Comamonadaceae (0.010% (0.001%, 0.031%) vs. 0.049% (0.011%, 0.310%), Z=-2.24, P=0.025; 0.031% (0.015%, 0.092%) vs. 0.118% (0.046%, 0.410%), Z=-2.10, P=0.036; 0.046% (0.036%, 0.062%) vs. 0.110% (0.045%, 0.176%), Z=-2.01, P=0.045). Linear discriminant analysis (LDA) effect sized showed that at the genus level, only Helicobacter was significantly enriched in Hp-positive group (LDA=4.89, P=0.045), while Streptococcus and Fusobacterium significantly enriched in Hp-negative group (LDA=3.28, 3.11;P=0.036,0.025, respectively). PICRUSt microbial function prediction showed that the expression of oxidative phosphorylation and disease-related pathways (pathways in cancer, renal cell carcinoma, amoebiasis, type 1 diabetes mellitus) in Hp-positive group were significantly higher than that in Hp-negative group (all P<0.05), while the expression of pathways such as energy metabolism and phosphotransferase system pathways were significantly lower than that in Hp-negative group (all P<0.05). Conclusion: In children with Hp-infected duodenal ulcers, the mucosal microbiota of the duodenal bulb is altered, characterized by an increased abundance of Helicobacter and a decreased abundance of Clostridium and Streptococcus, and possibly alters the biological function of the commensal microbiota through specific metabolic pathways.

[Analysis of risk factors for post-polypectomy bleeding and polyp recurrence after colonoscopic polypectomy in children].

Objective: To explore the incidence and the risk factors of post-polypectomy bleeding and polyp recurrence after colonoscopic high-frequency electrocoagulation snare polypectomy. Methods: Clinical data of 1 826 children who underwent colonoscopic high-frequency electrocoagulation snare polypectomy in the Children's Hospital, Zhejiang University School of Medicine from January 2009 to December 2020 was retrospectively analyzed. Demographic characteristics, endoscopic manifestations, pathological features, diagnosis, occurrence of post-polypectomy bleeding and polyp recurrence were collected. The associated risk factors were analyzed by Logistic regression. Results: A total of 1 826 children (1 191 males and 635 females) with 1 967 polypectomies were included. The age was 4.6 (3.2, 6.4) years at initial diagnosis. According to the initial colonoscopy, 1 611 children (88.2%) had solitary polyps, 1 707 children (93.5%) had pedicled polyps, 1 151 children (63.0%) had polyps involving the rectum, and 1 757 children (96.2%) had hamartomatous polyps. Polyposis syndromes were diagnosed in 73 children (4.0%). The post-polypectomy bleeding occurrence was 3.8% (75/1 967). Polyps recurred in 88 children (4.8%). Girls (OR=2.01, 95%CI 1.26-3.23) and sessile polyps (OR=2.28, 95%CI 1.15-4.49) were risk factors for post-polypectomy bleeding (both P<0.05). Multiple polyps (OR=17.49, 95%CI 9.82-31.18), right-colon involvement (OR=3.44, 95%CI 1.89-6.26) and non-hamartoma (OR=2.51, 95%CI 1.04-6.07) were risk factors for polyp recurrence (all P<0.05). Conclusions: Colonoscopic high-frequency electrocoagulation snare polypectomy has low incidence of post-polypectomy bleeding and polyp recurrence. Female patients and sessile polyps have higher risk for post-polypectomy bleeding. Multiple polyps, right-colon involvement and non-hamartoma polyps increase the risk for polyp recurrence.

Expression of transforming growth factor-ß1 and connective tissue growth factor in congenital biliary atresia and neonatal hepatitis liver tissue.

We investigated the expression of transforming growth factor-ß1 (TGF-ß1) and connective tissue growth factor (CTGF) in the liver tissue of infants with congenital biliary atresia and neonatal hepatitis, as well as the relationship between the expression of the two factors and liver fibrosis. Thirty-six infants who met the cholestasis criteria were classified into congenital biliary atresia and neonatal hepatitis groups. All specimens were stained with hematoxylin and eosin and Masson's trichrome, and the degree of liver fibrosis was assessed. The scope and level of CTGF and TGF-ß1 expression in the different specimens was evaluated by immunohistochemistry and observation. Liver fibrosis in the congenital biliary atresia group was more advanced than that in the neonatal hepatitis group, and the difference was significant (P < 0.01). In the neonatal hepatitis patients, CTGF and TGF-ß1 were mainly expressed in the hepatocytes, while they were expressed in both hepatocytes and biliary epithelial cells in the congenital biliary atresia patients, and in these patients the expression was significantly stronger than in the neonatal hepatitis patients (P < 0.01). With the aggravation of hepatic fibrosis, CTGF and TGF-ß1 expression levels in liver tissue gradually increased, and their expression levels were significantly correlated (P < 0.01). Liver fibrosis is present in both congenital biliary atresia and neonatal hepatitis patients. The gradual increase of CTGF and TGF-ß1 expression levels in liver tissue is associated with liver fibrosis. Early expression of CTGF and TGF-ß1 in biliary epithelial cells may be involved in the pathogenesis of congenital biliary atresia.