Objective To explore the role of ring finger protein 41(RNF41)in the initiation and progression of cholangiocarcinoma.Methods The expression levels of RNF41 mRNA and protein in tumor tissues and adjacent normal tissues from 84 CHOL patients who underwent total surgical resection at the Second Affiliated Hospital of Kunming Medical University and Kunming Ganmei Hospital between January 2010 and December 2016 were analyzed using bioinformatics,Western blot,and immunohistochemistry.The TIMER 2.0 database was used to analyze the impact of RNF41 on the prognosis and survival of CHOL patients and the relationship between RNF41 and tumor clinical characteristics.RNF41 siRNA was transfected into HCC9810,RBE,and HUCCT1 cells.CCK-8,Edu,colony formation,and Western blot assays were conducted to evaluate the changes in proliferation of cholangiocarcinoma cells between the RNF41 knockdown group and the control group.Transwell assays and detection of EMT and migration markers were performed to assess changes in the invasion ability of cholangiocarcinoma cells between the RNF41 knockdown and control groups.Western blot was used to examine the effect of RNF41 knockdown on epithelial-mesenchymal transition in cholangiocarcinoma cells.Twelve BALB/c mice were randomly divided into two groups:a control group and an RNF41 knockdown group,with six mice in each group.Tumor formation assays,Western blot assays,and immunohistochemistry staining were carried out to investigate the effect of RNF41 knockdown on tumor growth in nude mice.Results Real-time quantitative fluorescence PCR analysis revealed that the expression level of RNF41 mRNA in cholangiocarcinoma tissues was significantly higher than that in the corresponding adjacent non-tumor tissues(P<0.01),and this trend was corroborated at the protein level by immunohistochemical staining.Using the TIMER 2.0 database,we further analyzed the correlation between RNF41 expression and clinicopathological features,including histological grade,tumor stage,lymph node metastasis,and patient survival.The results indicated that elevated RNF41 expression was significantly associated with advanced histological grade and lymph node metastasis in cholangiocarcinoma(P<0.01).Survival analysis demonstrated that high RNF41 expression was closely linked to poor prognosis in patients with cholangiocarcinoma(CHOL).Functional assays,including CCK-8,EdU incorporation,and colony formation,showed that RNF41 knockdown significantly inhibited the proliferation of cholangiocarcinoma cells compared with the control group.Western blot analysis revealed that,following RNF41 silencing,the expression of the epithelial-mesenchymal transition(EMT)marker E-cadherin was markedly upregulated,whereas the levels of mesenchymal markers N-cadherin and MMP9 were significantly reduced(P<0.05).These findings were consistent with the results obtained from in vitro experiments(P<0.01).Moreover,in vivo studies showed that RNF41 knockdown suppressed subcutaneous tumor formation in nude mice(P<0.05).Conclusion RNF41 plays a critical role in promoting the occurrence and progression of cholangiocarcinoma and is closely associated with adverse clinicopathological features and poor prognosis in patients.The knockdown of RNF41 effectively suppresses the proliferation,invasion,epithelial-mesenchymal transition(EMT),and tumorigenicity of cholangiocarcinoma cells.

BACKGROUND:Increasing evidence suggests that N6-methyladenosine(m6A)regulators are closely associated with osteoarthritis and are considered to be a new direction in the prevention and treatment of osteoarthritis,but their specific mechanism of action is unknown. OBJECTIVE:To conduct a bioinformatics analysis of the osteoarthritis gene microarray dataset in order to explore the role of m6A in osteoarthritis and analyze the pathogenesis of osteoarthritis. METHODS:The m6A regulators associated with osteoarthritis and their expression were first extracted from the GSE1919 dataset in the GEO database using R software,and then the results were analyzed by gene difference analysis and GO and KEGG enrichment analyses.Subsequently,the results of protein-protein interaction network topology analysis and machine learning results were intersected to obtain the m6A Hub regulators,which were validated by in vitro cellular experiments. RESULTS AND CONCLUSION:A total of 16 osteoarthritis-related m6A regulators were extracted and 11 m6A differential regulators,including ZC3H13,YTHDC1,YTHDF3 and HNRNPC,were obtained by differential analysis.GO enrichment analysis showed that osteoarthritis-related m6A differential regulators played a role in the biological processes such as mRNA transport,RNA catabolism,and regulation of insulin-like growth factor receptor signaling pathway.(3)KEGG enrichment analysis showed that the differential regulators were mainly involved in the p53,interleukin-17 and AMPK signaling pathways.The combined protein-protein interaction network topology analysis and machine learning results obtained the m6A Hub regulator-YTHDC1.(5)The results of in vitro cellular experiments showed that there was a significant difference in the expression of m6A key regulator between the control and experimental groups(P<0.05).To conclude,YTHDC1 is closely related to the development of osteoarthritis,which is expected to be a molecular target of m6A for the treatment of osteoarthritis.

Long-term primary culture of mammalian cells has been always difficult due to unavoidable senescence. Conventional methods for generating immortalized cell lines usually require manipulation of genome which leads to change of important biological and genetic characteristics. Recently, conditional reprogramming (CR) emerges as a novel next generation tool for long-term culture of primary epithelium cells derived from almost all origins without alteration of genetic background of primary cells. CR co-cultures primary cells with inactivated mouse 3T3-J2 fibroblasts in the presence of RHO-related protein kinase (ROCK) inhibitor Y-27632, enabling primary cells to acquire stem-like characteristics while retain their ability to fully differentiate. With only a few years' development, CR shows broad prospects in applications in varied areas including disease modeling, regenerative medicine, drug evaluation, drug discovery as well as precision medicine. This review is thus to comprehensively summarize and assess current progress in understanding mechanism of CR and its wide applications, highlighting the value of CR in both basic and translational researches and discussing the challenges faced with CR.

Objective:To summarize the clinical characteristics and laboratory diagnostic methods of infant botulism caused by Clostridium botulinum type B. Methods:Clinical data of 3 infants with type B botulism who were admitted to Children′s Hospital Affiliated to Capital Institute of Pediatrics from May to November 2018 were retrospectively analyzed. Botulinum toxin was detected in fecal samples or fecal enrichment solution of the patients, and Clostridium botulinum was cultured and isolated from fecal samples. Results:The age of onset of the patients (two boys and one girl) was 3, 3 and 8 months old, respectively. Two cases had the onset in May and one case had the onset in November. There were two cases with mixed feeding and one case with breast feeding. One case′s family members engaged in meat processing. All of them were previously healthy. All the children presented with acute flaccid paralysis, cranial nerve involvement and difficult defecation. Two cases had secondary urinary tract infection. Electromyograms of two cases showed that action potential amplitude of the motor nerve were lower than those of their peers. After treatments including intravenous human immunoglobulin, respiratory tract management, urethral catheterization, nasal feeding, etc., three cases recovered completely 2 to 4 months later. Type B botulinum toxin was detected in the fecal diluent of one patient, and the TPGYT enrichment solution and cooked meet medium of the feces of 3 patients, respectively. Clostridium botulinum B was identified from the feces of 3 infants after culture, isolation and purification. Conclusions:Combined with typical clinical manifestations including acute flaccid paralysis, cranial nerve involvement symptoms and difficult defecation examination, infant botulism can be clinically diagnosed. The detection of fecal botulinum toxin and the culture and isolation of Clostridium botulinum are helpful for the diagnosis.

Objective To summarize the experience of prevention of biliary tract complications after liver transplantation from organ donation after citizen's death. Methods Clinical data of 88 cases undergoing liver transplantation from organ donation after citizen's death in the Affiliated Zhongshan Hospital of Sun Yat-sen University from October 2008 to December 2016 were retrospectively analyzed. Results Eighty-eight cases were eligible for the standards for organ donation after brain death plus cardiac death according to the Ⅲ national system for organ donation in China. According to the standard procedures, donor livers were successfully harvested and transplanted in 88 recipients. The biliary tract was reconstructed using the bile duct end-to-end anastomosis. The length of bile duct in the donors was shortened as possible. Slight tension should be maintained during anastomosis. Neither primary liver graft nonfunction nor rejection reaction occurred. One recipient suffered from bile leakage and recovered after drainage for 3 weeks. Two patients presented with biliary tract stenosis and mitigated after the placement of biliary tract stent. Conclusions The harvesting of donor liver should be in accordance with the standard procedures. The advantages of extracorporeal membrane oxygenation (ECMO) should be fully utilized to shorten warm and cold ischemia time as possible. Much attention should be diverted to the reconstruction of biliary tract, which contributes to decreasing the risk of biliary tract complications. Favorable clinical efficacy can be achieved in liver transplantation from organ donation after citizen's death.

Objective To investigate parameter changes for skin aging in murine model induced by D-galactose. Methods Sixty 3-month-old female mice were randomly divided into three groups: normal control group,low dose (80 mg/kg)and high dose (1000 mg/kg) D-galactose groups. After subcutaneous administration for 6 weeks, the aging models were established. Then, histochemical standards relating to aging were measured and morphologic alterations of surplus dorsal skin were observed under microscope and analyzed. Results In contrast with the control group, high dose D-galactose group showed that the thickness of dermis (624.5 ?48.5) ?m was significantly reduced (P