OBJECTIVETo investigate MUC2 expression in rat colons induced by probiotics and its effects on the inhibition of E.coli K1 (E44) penetration of the intestinal barrier by probiotics.

METHODSSD rats were subjected to intragastric administration of probiotics, E44, or probiotics +E44 on a daily basis for 7 days, and MUC2 expression in the colons was determined by RT-PCR. MUC2-targeted shRNA (shRNA MUC2) and scrambled shRNA plasmids (shRNA NC) were respectively transfected into Lovo cells, and the efficiency of MUC2 knockdown was determined using qRT-PCR. Competitive exclusion assay was used to evaluate the effects of the probiotics against E44 adhesion and invasion.

RESULTSIntestinal MUC2 mRNA expression was up-regulated in the rats after intragastric administration of probiotics, while E44 administration caused significantly lowered MUC2 expression. MUC2 expression was down-regulated (by 66.7%) by transfection with shRNA MUC2 in Lovo cells as compared with the negative control and mock control cells. The inhibition of E44 adherence and invasion by probiotics was significantly attenuated in transfected Lovo cell culture (in which the relative adhesion and invasion rates of E44 were 56.64% and 66.64%, respectively) as compared with those in the control group.

CONCLUSIONThe up-regulation of MUC2 in rat colons can be one of the mechanisms of the probiotics in antagonizing the translocation of the pathogenic bacteria. Silencing MUC2 expression causes attenuated inhibitory effect of the probiotics on E. coli K1 penetration across human intestinal epithelial cells.

Animals ; Animals, Newborn ; Cell Line, Tumor ; Colon ; drug effects ; metabolism ; microbiology ; Escherichia coli ; pathogenicity ; Escherichia coli Infections ; genetics ; Female ; Gene Expression Regulation, Neoplastic ; Gene Silencing ; Humans ; Mucin-2 ; genetics ; Probiotics ; pharmacology ; RNA, Messenger ; genetics ; RNA, Small Interfering ; Rats ; Rats, Sprague-Dawley ; Transfection

OBJECTIVETo construct dengue virus-specific full-length fully human antibody libraries using mammalian cell surface display technique.

METHODSTotal RNA was extracted from peripheral blood mononuclear cells (PBMCs) from convalescent patients with dengue fever. The reservoirs of the light chain and heavy chain variable regions (LCκ and VH) of the antibody genes were amplified by RT-PCR and inserted into the vector pDGB-HC-TM separately to construct the light chain and heavy chain libraries. The library DNAs were transfected into CHO cells and the expression of full-length fully human antibodies on the surface of CHO cells was analyzed by flow cytometry.

RESULTSUsing 1.2 µg of the total RNA isolated from the PBMCs as the template, the LCκ and VH were amplified and the full-length fully human antibody mammalian display libraries were constructed. The kappa light chain gene library had a size of 1.45×10(4) and the heavy chain gene library had a size of 1.8×10(5). Sequence analysis showed that 8 out of the 10 light chain clones and 7 out of the 10 heavy chain clones randomly picked up from the constructed libraries contained correct open reading frames. FACS analysis demonstrated that all the 15 clones with correct open reading frames expressed full-length antibodies, which could be detected on CHO cell surfaces. After co-transfection of the heavy chain and light chain gene libraries into CHO cells, the expression of full-length antibodies on CHO cell surfaces could be detected by FACS analysis with an expressible diversity of the antibody library reaching 1.46×10(9) [(1.45×10(4)×80%)×(1.8×10(5)×70%)].

CONCLUSIONUsing 1.2 µg of total RNA as template, the LCκ and VH full-length fully human antibody libraries against dengue virus have been successfully constructed with an expressible diversity of 10(9).

Animals ; Antibodies, Viral ; CHO Cells ; Cell Surface Display Techniques ; Cricetinae ; Cricetulus ; Dengue Virus ; immunology ; Gene Library ; Genetic Vectors ; Humans ; Immunoglobulin Heavy Chains ; immunology ; Transfection

Objective:To explore the efficacy and adverse effects of docetaxel combined with capecitabine on the basis of anthracycline in the treatment of breast cancer patient on the basis of anthracycline,and to provide evidence-based medicine evidence for the clinical application of capecitabine.Methods:PubMed,EMBase,CNKI,VIP and Wanfang database were used to search the randomized controlled trials in which the breast cancer patients were treated by docetaxel combined with capecitabine and docetaxel alone.The qualities of the included studies were assessed by the modified Jadad scale.The effective data were extracted and the pathologic complete remission (pCR),recurrence-free survival (RFS),disease-free survival (DFS)and safety were evaluated by RevMan 5.3 software.Results:A total of 10 articles were included,including 12012 patients.The Meta-analysis results showed that there were no statistically significant differences in pCR (RR=1.04,95%CI:0.91-1.18,P =0.59),RFS (RR=0.86,95%CI:0.71 - 1.03,P = 0.10)and DFS (RR= 0.98,95% CI:0.86 - 1.11,P = 0.71)between docetaxel combined with capecitabine and docetaxel alone. The clinical safety analysis results showed that the patients treated with docetaxel combined with capecitabine were susceptible to hand-foot syndrome (OR= 7.13, 95%CI:4.76-10.69,P <0.001)and stomatitis (OR = 1.93,95%CI:1.10-3.40,P =0.02).Conclusion:On the basis of anthracycline treatment,the efficacies of docetaxel combined with capecitabine and docetaxel alone in the treatment of the breast cancer patients are similar.The former is more likely to cause the hand-foot syndrome and stomatitis.

Objective:To analyze the accuracy of lung ultrasound and chest X-ray in the diagnosis of neonatal pulmonary disease.Methods:We prospectively collected newborns that needed chest X-ray examination to diagnose pulmonary disease from twelve neonatal intensive care units across the country between June 2019 and April 2020.Each newborn was examined by lung ultrasound within two hours after chest X-ray examination.All chest X-ray and lung ultrasound images were independently read by a radiologist and a sonographer.When there was a disagreement, a panel of two experienced physicians made a final diagnosis based on the clinical history, chest X-ray and lung ultrasound images.Results:A total of 1 100 newborns were enrolled in our study.The diagnostic agreement between chest X-ray and lung ultrasound(Cohen′s kappa coefficient=0.347) was fair.Lung ultrasound(area under the curve=0.778; 95% CI 0.753-0.803) performed significantly better than chest X-ray(area under the curve=0.513; 95% CI 0.483-0.543) in the diagnosis of transient tachypnea of the newborn( P<0.001). The accuracy of lung ultrasound in diagnosing neonatal respiratory distress syndrome, meconium aspiration syndrome, pneumonia and neonatal pulmonary atelectasis was similar to that of chest X-ray. Conclusion:Lung ultrasound, as a low-cost, simple and radiation-free auxiliary examination method, has a diagnostic accuracy close to or even better than that of chest X-ray, which may replace chest X-ray in the diagnosis of some neonatal lung diseases.It should be noted that both chest X-ray and lung ultrasound can only be used as auxiliary means for the diagnosis of lung diseases, and it is necessary to combine imaging with the clinical history and presentation.