ABSTRACT
Objective:To analyze the molecular characteristics of Echovirus 11 (Echo11) strains isolated in Xiangyang, Hubei Province from 2016 to 2017 based on the sequences of VP1 gene.Methods:Rectal and throat swab specimens were collected from children with hand, foot and mouth disease (HFMD) in Xiangyang from 2016 to 2017. Echo11 strains were detected by real-time reverse transcriptase PCR (RT-PCR) and isolated after cultured in human rhabdosarcoma (RD) cells. The VP1 regions of Echo11 strains isolated from RD cells and the whole genomes of three representative Echo11 strains were amplified by conventional RT-PCR and the sequences were analyzed. DNAStar7.0 (MegAlign) and MEGA6.0 (Data) were used to analyze the homology and mutation sites in nucleotide and amino acid sequences. Neighbor-joining method was used to construct phylogenetic trees. Recombination analysis was performed with SimPlot software (BootScanning).Results:A total of 11 Echo11 strains were isolated from 3 494 HFMD cases, accounting for 0.31%. They were highly homologous in the VP1 gene. These strains shared 98.4%-100.0% homology in nucleotide sequences and 98.3%-100.0% homology in amino acid sequences. The homology between the 11 Echo11 strains and the prototype strain (Echo11/Gregory, X80059) was 73.9%-74.8% in nucleotide sequences and 87.7%-88.7% in amino acid sequences. All of the Echo11 strains circulating in Xiangyang were classified into lineage D, having a similarity to the strains circulating in some regions of mainland China since 2013. In multiple regions of the genome, the Echo11 strains isolated in Xiangyang were highly similar to the Henan Echo1 strains in 2010 and the Hubei Echo6 strains in 2015, suggesting there was recombination within the genome of Echo11 strains in Xiangyang.Conclusions:The Echo11 strains circulating in Xiangyang from 2016 to 2017 belonged to lineage D and were recombinant strains.
ABSTRACT
Objective To detect and analyze enteroviruses causing suspected aseptic meningitis in a kindergarten in Jinhua City, Zhejiang Province. Methods Viral RNA was extracted from samples and cDNA was prepared by reverse transcription. PCR was performed to amplify the partial sequences of the 5′-untranslated region ( UTR) and VP1 gene of enteroviruses. Serotypes of the viruses were determined by com-paring the homology between the partial sequences of VP1 gene. Phylogenetic tree of the partial VP1 se-quences was constructed using MEGA6. Results This study included seven patients and twenty-six asymp-tomatic students. Coxsakievirus A10 (CV-A10) was detected in 48. 5％ of the students and echovirus 6 (Echo 6) in 21. 2％. Besides, 12. 1％ of the students might be co-infected by the two viruses. Among the seven patients, six were infected by CV-A10 and the other one might have co-infection. According to the phylogenetic analysis, CV-A10 strains detected in this study were closely related to those isolated in China in recent years, including the strains isolated in Xiamen in 2015 and Yunnan in 2017, while the Echo 6 strains were phylogenetically related to those isolated in Yunnan, Guangzhou and Shandong in 2014. Conclusions CV-A10 and Echo 6 were detected in the cases with suspected aseptic meningitis and had close phylogenetic relationships to the strains appeared in China in recent years.
ABSTRACT
Objective@#To construct the prokaryotic plasmid expressing the recombinant protein Coxsackie virus A6 VP1 or VP2 and prepare the antiserum of rabbit anti-CVA6 VP1 or anti-CVA6 VP2.@*Methods@#CVA6 VP1and VP2 gene fragments were amplified by reverse transcription PCR and inserted into the prokaryotic expression vectors. The recombinant plasmids were expressed in E. coli BL21 (DE3). After induction with Isopropyl β-D-Thiogalactoside (IPTG), the fusion proteins were obtained, and then purified by SDS-PAGE electrophoresis and gel extraction. The polyclonal antibodies were prepared by immunizing rabbits with the fusion proteins and analyzed with Western blot(WB) and indirect immunofluorescence assay(IFA).@*Results@#The prokaryotic expression vector of CVA6 VP1 or VP2 was confirmed by PCR, double enzyme digestion and sequencing. CVA6 VP1 and VP2 fusion proteins with high purity were obtained. WB and IFA were used to identify polyclonal antibodies.@*Conclusions@#The CVA6 VP1 and VP2 prokaryotic expression vectors were successfully constructed, and the recombinant CVA6 VP1 and VP2 proteins and their corresponding polyclonal antibodies were obtained.
ABSTRACT
In the present study, the effect of serum (fetal bovine serum, FBS) on cellular uptake behaviors of DNA tetrahedron (TDNs) was investigated.Fluorescence-labeled TDNs were synthesized by self-assembly and purified with HPLC to achieve TDNs product with purity of 95%.By means of flow cytometry and confocal microscopy, the kinetics of TDNs endocytosis in HeLa cells in the presence or absence of FBS was compared.The results showed that TDNs remained intact in complete medium and cell lysate for more than 12 hours.FBS increased the amount of internalized TDNs in HeLa cells, whereas it did not change the route of caveolin-dependent endocytosis.Herein, our study provided a new insight into the effects of biomolecules on the interaction between cells and DNA nanostructures, which helped the future development of DNA-based intracellular nanocarriers.
ABSTRACT
Objective: To analyze the influence of long-term swimming training on spatial learning-memory in rats and its relationship with cyclic adenosine monophosphate(cAMP) and cyclic guanosine monophosphate(cGMP) signal transduction pathway. Method: After 3 times adaptable swimming exercises (30min each time), 40 male SD rats were divided into 2 groups: control group (CR, n=20) and exercises, group (TR, n=20). CR group didn't swim, and TR group swam without burden (6 times/week, 60 min each time). After 8 weeks training, 10 rats were selected from both groups respectively for examing of Morris water maze test. Radioimmunoassay was used to measure the levels of cAMP and cGMP in hippocampus and prefrontal cortex of rats. Result: ①Compared with CR group, in TR group learning-memory improved in a certain extent: ②Compared with CR group, in TR group, the level of cAMP in hippocampus enhanced very obviously (P＜0.01), the cAMP/cGMP ratio enhanced obviously (P＜0.05); in prefrontal cortex the levels of cAMP and cAMP/cGMP ratio enhanced obviously (P＜0.05). Conclusion: Swimming training for 8 weeks improved the spatial learning-memory of rats in a certain extent, and elevated the level of cAMP and cAMP/cGMP ratio in hippocampus and prefrontal cortex of rats obviously. It is suggested that exercises might affect learning-memory by cAMP and cGMP signal transduction pathway.
ABSTRACT
0.05),but the 24h urine zinc level increased markedly(P