Preliminary exploration of animal models of congenital choledochal cysts.

BACKGROUND: Various animal models have been used to explore the pathogenesis of choledochal cysts (CCs), but with little convincing results. Current surgical techniques can achieve satisfactory outcomes for treatment of CCs. Consequently, recent studies have focused more on clinical issues rather than basic research. Therefore, we need appropriate animal models to further basic research. AIM: To establish an appropriate animal model that may contribute to the investigation of the pathogenesis of CCs. METHODS: Eighty-four specific pathogen-free female Sprague-Dawley rats were randomly allocated to a surgical group, sham surgical group, or control group. A rat model of CC was established by partial ligation of the bile duct. The reliability of the model was confirmed by measurements of serum biochemical indices, morphology of common bile ducts of the rats as well as molecular biology experiments in rat and human tissues. RESULTS: Dilation classified as mild (diameter, ≥ 1 mm to < 3 mm), moderate (≥ 3 mm to < 10 mm), and severe (≥ 10 mm) was observed in 17, 17, and 2 rats in the surgical group, respectively, while no dilation was observed in the control and sham surgical groups. Serum levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin, and total bile acids were significantly elevated in the surgical group as compared to the control group 7 d after surgery, while direct bilirubin, total bilirubin, and gamma-glutamyltransferase were further increased 14 d after surgery. Most of the biochemical indices gradually decreased to normal ranges 28 d after surgery. The protein expression trend of signal transducer and activator of transcription 3 in rat model was consistent with the human CC tissues. CONCLUSION: The model of partial ligation of the bile duct of juvenile rats could morphologically simulate the cystic or fusiform CC, which may contribute to investigating the pathogenesis of CC.

Impact of Radiotherapy Combined With Chemotherapy on Long-Term Outcomes of Patients With Recurrent Nasopharyngeal Carcinoma.

Background: It remains controversial whether the application of chemotherapy has an impact on recurrent nasopharyngeal carcinoma (rNPC) patients with salvage radiotherapy. Here, we aimed to evaluate treatment outcomes of rNPC patients and derive a prognostic model to assess the benefit of chemotherapy in patients with re-radiotherapy. Methods: This study was conducted as a retrospective study. In total, 340 rNPC patients treated with salvage intensity-modulated radiotherapy (IMRT) or radiochemotherapy (RCT) from October 2006 to September 2019 were included in this study. Overall survival (OS) was the primary outcome. Kaplan-Meier method was employed to detect the prognostic difference with Log-rank tests. The Cox regression analysis was performed to explore the potential prognostic factors while the multivariate Cox analysis was used to identify candidate variables for the prognostic model of OS. Results: The 5-year actuarial rates of OS, progression-free survival, loco-regional progression-free survival, and distant metastases-free survival did not show significant difference between the IMRT and RCT groups (P > .05). Age at recurrence and rT category were found to be the independent prognostic factors for OS. We found that rNPC patients suffered poor OS in the high-risk group (patients with higher age at recurrence and advanced rT category) (high-risk vs low-risk, HR = 1.87, 95% CI: 1.36-2.57, P < .001). Salvage RT alone may be superior to RCT for patients in the low-risk group (RCT group vs RT group, HR = 1.89, 95% CI: 1.11-3.20, P = .038). Conclusion: Salvage RT combined with chemotherapy cannot improve survival outcomes for rNPC. More novel clinical trials should be explored to develop individualized strategies to improve survival and minimize toxicities.

Single-Step Synthesis of Atropisomers with Vicinal C-C and C-N Diaxes by Cobalt-Catalyzed Atroposelective C-H Annulation.

The atroposelective synthesis of atropisomers with vicinal diaxes remains rare and challenging, due to the steric influence between the two axes and their unique topology. Herein, we disclose a single-step construction of atropisomers with vicinal C-C and C-N chiral diaxes by cyclopentadiene (Cp)-free cobalt-catalyzed intramolecular atroposelective C-H annulation, providing the desired diaxial atropisomers of unique structures with decent stereocontrols of both axes (up to >99 % ee and 70 : 1 dr). The optically pure products bearing fluorophores show circular polarized luminescence (CPL) properties, being candidate materials for potential CPL applications. Atropisomerization experiments and density function theory (DFT) calculations are conducted to study the rotational barriers and rotation pathways of the diaxes.

Diagnosis, treatment, and prevention of severe acute hepatitis of unknown etiology in children.

BACKGROUND: Severe acute hepatitis of unknown etiology in children has recently exhibited a global trend of concentrated occurrence. This review aimed to summarize the current available information regarding the outbreak of severe acute hepatitis and introduce our hospital's previous experiences with the diagnosis and treatment of severe acute hepatitis for reference. DATA SOURCES: Websites including the UK Health Security Agency, European Centre for Disease Prevention and Control, CDC, WHO, and databases including PubMed/Medline, Cochrane Library, Embase and Web of Science were searched for articles on severe acute hepatitis in children. RESULTS: As of May 26, 2022, a total of 650 cases have been reported in 33 countries; at least 38 (6%) children required liver transplantation, and nine (1%) died. Cases are predominantly aged between 3 and 5 years old, and there are no epidemiological links among them. The common manifestations are jaundice, vomiting and pale stools. Adenovirus tested positive in most cases, and SARS-CoV-2 and other viruses were detected in a few cases, but virus particles were not found in liver tissue. Adenovirus immunohistochemistry showed immunoreactivity in the intrasinusoidal lumen from some liver samples. The hierarchical treatment includes symptomatic and supportive therapy, management of coagulation disorders and hepatic encephalopathy, artificial liver support, and liver transplantation (approximately 6%-10% of cases require liver transplant). CONCLUSIONS: The etiology of this severe acute hepatitis in children is not clear. The clinical features are severe acute hepatitis with significantly elevated liver enzymes. Clinicians need to be alert to children with hepatitis.