Porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) are very two important pathogens that have coursed huge economic losses in swine production in worldwide. In this study,a vector pCMV-TJM containing the full-length cDNA clone of PRRSV attenuated strain TJM-F92 was firstly constructed by PCR method. Then a gene sequence containing Afl II/Mlu I e restriction enzyme sites and a transcription regulatory sequence for ORF6 (TRS6) was inserted be- tween ORF7 and 3'UTR, yielding a expression vector pCMV-TJM-TRS. Subsequently, a plasmid pCMV-TJM-Cap was constructed by cloning of PCV2 ORF2 gene into the unique sites Afl II /Mlu I of pCMV- TJM-TRS plasmid DNA. Then three recombinant PRRSV, rTJM, rTJM/TRS and rTJM/Cap, were rescued by transfection of pCMV-TJM, pCMV-TJM-TRS and pCMV-TJM-Cap into Marc-145 cells, respectively,and confirmed by the genome sequence, restriction enzyme digestion, Western Blot and IFA. They all had the molecular markers which was different from the parent virus. The growth characteristics of the rescued viruses were similar to that of parent virus. rTJM/Cap could also express efficiently PCV2 Cap protein in Marc-145 cells. At passage 8, it still had PCV2 ORF2 gene which examined by RT-PCR. It indicated that the full-length cDNA clone of PRRSV attenuated strain TJM-F92 and recombinant PRRSV rTJM/Cap expressing PCV2 Cap protein were successfully constructed. It made an important foundation for studying on the pathogenic mechanisms of PRRSV and PRRSV-PCV2 vaccine in the future.
Animals ; Capsid Proteins ; genetics ; immunology ; Cell Line ; Circoviridae Infections ; veterinary ; virology ; Circovirus ; classification ; genetics ; metabolism ; Gene Expression ; Open Reading Frames ; Porcine Reproductive and Respiratory Syndrome ; virology ; Porcine respiratory and reproductive syndrome virus ; genetics ; metabolism ; Recombination, Genetic ; Swine ; Swine Diseases ; virology ; Viral Vaccines ; genetics ; immunology

Objective To investigate the effect of transcription factor specific protein5(Sp5)silencing on Wnt signaling pathway correlated factors and cell proliferation ability in mouse embryo palatal mesenchymal cells(mEPMCs).Methods mEPMCs of 14.5 d pregnant C57BL/6J mice were isolated and cultured in vitro.Cell source was identified by immunofluorescence staining.Lentivirus transfection technique was used to silence the expression of Sp5 gene in mEPMCs,and the transfection efficiency was verified by Western blot assay.Follow-up experiments were set up with the blank control group,the no-load virus group and the slience group(the Sp5-shRNA group).The protein and mRNA expression levels of β-catenin,GSK-3β,Wnt3a and CyclinD1 were detected by Western blot assay and RT-qPCR after transfection for 72 h in each group.Cell proliferation capacity was detected by CCK-8.The proliferation rate of 5-Ethynyl-2'-deoxyuridine(EdU)positive cells was detected by immunofluorescence assay.Cell cycle was detected by flow cytometry.Results mEPMCs were successfully isolated,and Sp5 expression was silenced.Western blot and RT-qPCR results showed that the protein and mRNA expressions of β-catenin,GSK-3β,Wnt3a and CyclinD1 were significantly higher in the Sp5-shRNA group than those in the blank control group and the no-loaded virus group(P<0.05).The proliferative ability and the proliferative rate of EdU positive cells were higher in the Sp5-shRNA group than those in the blank control group and the no-loaded virus group(P<0.05).The proportion of mEPMCs in S phase was higher in the Sp5-shRNA group than that in the blank control group and the no-loaded virus group(P<0.05).Conclusion Sp5 in silenced mEPMCs can participate in palate development and promote the proliferation of mEPMCs by regulating Wnt signaling pathway.

Objective:To summarize the experience of five hospitals in Guangdong Province on successfully transporting retained passengers by chartered flights during the outbreak of the COVID-19.Methods:We retrospectively evaluated the operation and management, cabin arrangement, isolation requirements, and personnel protection in the aspect of epidemic prevention and control.Results:In 11 charter missions, over one thousand "healthy" passengers with potential risk of infections were transported back to China. The medical delivery team and flight crew were kept free of infection, passengers maintained zero cluster infections and no unexpected adverse events during the air transport.Conclusions:Our results indicate how to carry passengers in a scientific and orderly way is crucial for avoiding the transmission risks of the epidemic of COVID-19 among working staffers and passengers during air transportation.

With the increasing global burden of various cancer, an abundance of papers emerged every year in the research hotspots of oncology, covering a wide range of research types and topics. In order to facilitate interested readers to quickly grasp the frontier and hotspots of cancer research, it would be helpful to sort out and summarize the research topic in a timely manner. According to the classification of disciplines, we screened the Essential Science Indicators (ESI) hot papers released in 2019 for the ones in the oncology field, utilized methods such as bibliometrics, statistical description, hierarchical induction, analysis and interpretation to further reveal the context and characteristics of research in the field of oncology, summarized the latest progresses and future directions in the field, and provided information and hints for the trajectory of future research. A total of 549 papers were included, which were mainly from the field of clinical medicine; the country with the most publications was the United States, while China ranked the fourth in terms of contribution; the research institution with the highest number of published papers was University of Texas system;
Bibliometrics ; Biomedical Research ; China ; Humans ; Neoplasms ; Publications ; United States