Application of gut microbiome in the diagnosis and treatment of tumor / 国际肿瘤学杂志

Gut microbiome is closely related to human health. Changes in intestinal microbial composition promote the development of tumors. Specific intestinal microorganisms and their metabolites regulate host physiological functions and tumor microenvironment, significantly affecting the anti-cancer treatment response and its adverse events. Strategies targeting gut microbiome have shown promising prospects in diagnosis and treatment of cancer.

Clinical characteristics of the recovered COVID-19 patients with re-detectable positive RNA test

BackgroundIt has been reported that several cases recovered from COVID-19 tested positive for SARS-CoV-2 after discharge (re-detectable positive, RP), however the clinical characteristics, significance and potential cause of RP patients remained elusive. MethodsA total of 262 COVID-19 patients were discharged from January 23 to February 25, 2020, and were enrolled for analysis of their clinical parameters. The RP and non-RP (NRP) patients were grouped according to the disease severity during their hospitalization period. The clinical characterization at re-admission to the hospital was analyzed. SARS-CoV-2 RNA and plasma antibody levels were detected using high-sensitive detection methods. FindingsUp to March 10, 2020, all of patients were followed up for at least 14 days, and 38/262 of RP patients (14.5%) were present. The RP patients were characterized by being less than 14-years old and having mild and moderate conditions as compared to NRP patients, while no severe patients became RP. Retrospectively, the RP patients displayed fewer symptoms, more sustained remission of CT imaging and earlier RNA negative-conversion but similar plasma antibody levels during their hospitalization period as compared to those NRP patients. When re-admitted to the hospital, these RP patients showed no obvious clinical symptoms or disease progression indicated by normal or improving CT imaging and inflammatory cytokine levels. All 21 close contacts of RP patients were tested negative for SARS-CoV-2 RNA, and no suspicious clinical symptoms were reported. However, 18/24 of RNA-negative samples detected by the commercial kit were tested to be positive for virus RNA using a hyper-sensitive method, suggesting the carrier status of virus possibly existed in patients recovered from COVID-19. InterpretationOur results showed that young and mild COVID-19 patients seem to be RP patients after discharge, who show no obviously clinical symptoms and disease progression upon re-admission. More sensitive RNA detection methods are required to monitor these patients during follow-up. Our findings provide empirical information and evidence for the effective management of COVID-19 patients during their convalescent phase.

Cultivation,identification and sorting of bronchoalveolar stem cells derived from mouse lung / 第三军医大学学报

Objective To cultivate,identify and sort bronchoalveolar stem cells(BASC)derived from normal adult mouse lung.Methods After enzymatic digestion of lung tissue with dispase and collagenase in combination,the Sca-1+ cells were isolated from the obtained pulmonary cells by magnetic cell sorting.These Sca-1+ cells were cultured in dishes coated with collagen and mouse fibroblast cell line Swiss-3T3 under a serum-free culture system for BASC,which were identified by the dual-color immunofluorescent staining clara cell specific antigen(CCA)and surfactant protein C(SP-C).Finally,these pure BASC were isolated by the flow cytometry.Results One lung of normal adult mouse could yield(1.6-1.8)?107 nucleated cells in this enzyme digestion procedure.The percentage of Sca-1+ cells we sorted from lung tissue was much higher than the unsorted [(87.3?5.9)% and(9.6?1.8)%,P

Construction of the eukaryotic expression vector of mouse 24p3 gene and its expression in NIH3T3 cell lines / 第三军医大学学报

Objective To construct the eukaryotic expression vector of mouse 24p3 gene and express it in NIH3T3 fibroblast cell line and verify its biological function of delivering iron into cells. Methods 24p3cDNA was cloned by RT-PCR and the eukaryotic expression vector of mouse 24p3 gene was constructed by gene recombination technique and the recombinant plasmid was verified by restriction enzyme digestion analysis and sequenceing, then transfected into NIH3T3 cells using DOTAP transfection reagent. Then the positive clones were selected and amplified. The expression of 24p3 gene in the culture supernatant of positive clones was analyzed by ELISA and Western blotting and its biological activity of delivering iron into cells was tested by atomic absorption spectrometer. Results The eukaryotic expression vector was constructed successfully. The NIH3T3 cells that stably expressed 24p3 were screened out. 24p3/SIP24 protein could express in the culture supernatant of positive clones and deliver iron into NIH3T3 cells. Conclusion The 24p3 gene was expressed successfully in the transfected NIH3T3 cells with good biological activity, which laid the foundation for further studying its biological function and mechanism involved in the iron metabolism.