Objective:To investigate the effects of pre-existing antibody on seroconversion rate after influenza vaccination.Methods:This study recruited 1 900 healthy volunteers to receive influenza split vaccines in Xinjiang Uygur Autonomous region and Yunnan Province from September 2009 to October 2018. Hemagglutinin agglutination inhibition assay was used to detect the titers of specific antibodies in blood samples collected before vaccination and 28 d after vaccination and the effects of pre-existing antibody on the seroconversion to different influenza vaccine components were analyzed.Results:Trend analysis showed that with the increasing titer of pre-existing antibody, the seroconversion rates to A/H1N1, A/H3N2, B/Victoria and B/Yamagata vaccine components were gradually decreased (χ 2=121.76, P<0.001; χ 2=67.58, P<0.001; χ 2=45.25, P<0.001; χ 2=54.55, P<0.001). After adjusting for factors such as region, gender and age, multivariate logistic regression showed that pre-existing antibody titer equal to or higher than 40 was an independent factor that affected the seroconversion to A/H1N1, A/H3N2 and B/Victoria vaccine components, and the adjusted OR (95%CI) values were 2.50(2.00-3.13)、1.64(1.35-2.00) and 2.50(1.79-3.45), respectively. Conclusions:The seroconversion rate to each vaccine component was negatively correlated with the pre-existing antibody titer. The factor that pre-existing antibody titer equal to or higher than 40 was detrimental to the seroconversion to A/H1N1, A/H3N2 and B/Victoria vaccine components, but had no significant influence on B/Yamagata seroconversion.

Objective:To investigate the mechanism of silent information regulator 1 (SIRT1) to restrict influenza virus infection and replication by regulating the downstream proteins.Methods:SIRT1 knockout A549 cell line was constructed by CRISPR-Cas9 technology. The wild-type and SIRT1 knockout A549 cells were infected with influenza A virus. After 24 hours, cells were collected for RNA sequencing (RNA-Seq) and gene set enrichment analysis (GSEA). And the expression levels of the NP protein of influenza virus and SIRT1-related functional proteins in the two cell lines were determined by western blotting.Results:Influenza virus replication was enhanced in SIRT1 knockout A549 cell line. A total of 2 671 differentially expressed genes were detected by high-throughput sequencing, of which 2 012 were up-regulated and 659 were down-regulated, respectively. These differentially expressed genes are involved mainly in signaling pathways such as inflammatory response, apoptosis signal, innate immune antiviral responses, cytokine secretion, and so on. Western blot result indicated that compared with wild-type cell line, the rising degree of the expressions of IFITM3 (interferon-induced transmembrane protein 3) and autophagy protein LC3-II were lower in SIRT1 knockout cell line during influenza virus replication.Conclusions:This study shows that SIRT1 can inhibit influenza virus replication by regulating important proteins downstream such as IFITM3 and LC3-II.

Bone tissue engineering (BTE) is a rapidly developing strategy for repairing critical-sized bone defects to address the unmet need for bone augmentation and skeletal repair. Effective therapies for bone regeneration primarily require the coordinated combination of innovative scaffolds, seed cells, and biological factors. However, current techniques in bone tissue engineering have not yet reached valid translation into clinical applications because of several limitations, such as weaker osteogenic differentiation, inadequate vascularization of scaffolds, and inefficient growth factor delivery. Therefore, further standardized protocols and innovative measures are required to overcome these shortcomings and facilitate the clinical application of these techniques to enhance bone regeneration. Given the deficiency of comprehensive studies in the development in BTE, our review systematically introduces the new types of biomimetic and bifunctional scaffolds. We describe the cell sources, biology of seed cells, growth factors, vascular development, and the interactions of relevant molecules. Furthermore, we discuss the challenges and perspectives that may propel the direction of future clinical delivery in bone regeneration.
Animals ; Bone Regeneration ; Cell Differentiation ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Mesenchymal Stem Cell Transplantation ; Mesenchymal Stem Cells ; cytology ; Osteogenesis ; Tissue Engineering ; methods ; Tissue Scaffolds

Objective: Influenza H1N1 subtype vaccine candidate strains from a 2015—2016 year epidemic strain in China were prepared and identified by themethod of classical reassortment. Methods: The influenza H1N1 epidemic strain and H3N2 high-yield reassortant parental strain (X-157) were mixed and inoculated into embryonated chicken eggs by the classical reassortmentmethod . The negative selection of mixed culture virus was carried out with the antiserum of H3 protein and the antiserum of X-157 strain. Real-time PCRmethod was used to test the HA and NA genes. Restriction enzyme digestionmethod was used to identify the internal genes. HA and NA genes of selected strains were sequenced. The strain which HA and NA genes possessed the same amino acid constitution with the wild type virus was selected and immunized to ferret. Two-way test was carried out. Results: Five strains with expected HA and NA genes were selected by real-time PCR. Internal genes were identified, with 4 strains had 6+ 2 constitution, 1 strain had 5+ 3 constitution. Comparing with the wild type virus, HA and NA genes of the 5 strains had no mutation. HA titer of reassortant strains was above 1 024. HI titer of the selected NO.12 reassortment strain reached 5 120, and two-way test was passed. The yield of reassortant strain was 64 times that of the wild type strain. Conclusions A circulating influenza A (H1N1) strain of influenza A (2015—2016) was successfully prepared in China and laid the foundation for vaccine storage and disease prevention and control.

Objective To determine the incidence and prevalence of transient ischemic attack (TIA) and to evaluate its epidemiological situation in Hunan province.Methods Seven monitoring points were randomly selected from the province,a total of 8 311 subjects aged≥50 years were then chosen by stratified sampling.The cases counted in prevalence was defined as patients diagnosed before 24:00 o'clock August 31st,2013,and the new diagnosis for incident counting was defined as those diagnosed between 00:00 September 1st,2012 and 24:00 August 31st,2013.Results Among all 8 311 screened subjects,the number of TIA patients was 24 (288.8 per 100 000 people),the incidence of TIA was 7 (85.2 per 100 000 people).Standardized prevalence and incidence were 283.2 and 82.4 per 100 000 respectively using 2010 China census population.Among them,the standardized incidence rate of female was higher than that of male (114.8 per 100 000 person-years vs.48.8 per 100 000 person-years),and the prevalence rate of males was higher than that of female (288.2 per 100 000 people vs.273.2 per 100 000 people).Hypertension is the most important risk factor for TIA (55.2％).Conclusion The incidence and prevalence of TIA in Hunan province are higher than the national average.Hypertension is the main risk factor.

Objective To analyze the phenotypic characteristics of antiviral-resistant influenza B viruses circulating in mainland China and to analyze the susceptibility of influenza B viruses to neuraminidase inhibitors ( NAIs) . Methods Antiviral-resistant phenotyping test was performed to analyze the NAI suscep-tibility of 1 386 influenza B viruses isolated in mainland China from April 2014 to March 2015, including the test of susceptibility to oseltamivir and zanamivir. Results All of the 94 B-Victoria lineage viruses were sensitive to oseltamivir and zanamivir. Of all 1 292 B-Yamagata lineage viruses tested, 1 virus showed re-duced sensitivity to oseltamivir with NA gene containing I221T amino acid mutation, 10 viruses showed re-duced sensitivity to zanamivir with 4 having D197N amino acid mutation in NA gene, 3 viruses showed re-duced sensitivity to both oseltamivir and zanamivir with NA gene possessing D197N amino acid mutation and 1 virus carrying the A245T amino acid mutation in NA gene showed reduced sensitivity to oseltamivir and highly reduced sensitivity to zanamivir. Conclusion The majority of influenza B viruses circulating in main-land China during 2014 to 2015 were sensitive to NAIs, which indicated that NAIs could be used continually for clinical treatment of patients with influenza. Sustained monitoring of antiviral susceptibility of influenza B viruses should be emphasized for timely detection of antiviral resistant viruses and more attention should be paid to the D197N mutations in NA gene of influenza B viruses.

Objective To understand the antigenic and genetic characteristics of highly pathogenic avian influenza H5N1 viruses isolated from poultry related environments of surrounding areas of Qinghai Lake.Methods Poultry and wild birds related environments from surrounding areas of Qinghai lake were collected and handled.Viruses were isolated with embryonated chicken eggs.The virus subtyping was performed by real-time RT-PCR.The highly pathogenic avian influenza H5N1 viruses were chosen to conduct next generation sequencing and hemagglutination inhibition ( HI) assay.Results In total of 19 H5N1 virus strains were isolated, they were all from poultry related environments and collected in January-March of year 2013.Seven representative highly pathogenic avian influenza H5N1 viruses were sequenced and analyzed for antigenicity.According to phylogenetic analysis of HA gene, 6 viruses were belong to clade 2.3.2.1c except A/Environment/Qinghai/XN02032/2013 which belongs to clade 7.2.Antigenic analysis showed that 6 viruses were antigenically similar to A/Barn swallow/Hong Kong/D10-1161/2010, while A/Environment/Qinghai/XN02032/2013 presented low reaction with all reference antisera.Conclusions The existence of highly pathogenic avian influenza H5N1viruses in poultry related environments of surrounding areas of Qinghai Lake was confirmed.The status of highly pathogenic avian influenza H5N1 viruses with evolution diversity emphasized the necessary of strengthening the avian influenza surveillance in these areas.

Data based on the antiviral-resistant phenotyping characteristics of 884 influenza B viruses circulating in mainland China from October 2013 to March 2014 were analyzed to assess the susceptibility of influenza B viruses to neuraminidase inhibitors. All 884 viruses were sensitive to oseltamivir; two viruses (0.23%) had reduced sensitivity to zanamivir and all other viruses were sensitive to zanamivir. Among the 38 viruses with a B/Victoria lineage, B/Shandong-Kuiwen/1195/2014 exhibited a half-maximal inhibitory concentration (IC50) for zanamivir that was elevated by 5. 12-fold (1.78 nM) compared with neuraminidase inhibitors sensitive to the reference virus (0.34 nM), suggesting that it exhibited reduced inhibition by zanamivir. D35G, N59D and S402T (39, 64 and 399 with N2 number) amino-acid substitutions in the NA gene were detected with no previously reported antiviral-resistant substitutions. Among viruses with the 846 B/Yamagata lineage, B/Hunan-Lingling/350/2013 exhibited a 7.99-fold elevated IC50 for zanamivir (2.72 nM) compared with neuraminidase inhibitors sensitive to the reference virus (0.34 nM), suggesting that it exhibited reduced inhibition by zanamivir. D197N (N2 number), a previously reported antiviral resistant-related amino-acid substitution in the NA gene, was detected in B/Hunan-Lingling/350/2013. These data suggest that recently circulating influenza B viruses in mainland China have retained susceptibility to neuraminidase inhibitors.
Amino Acid Substitution ; Antiviral Agents ; pharmacology ; China ; epidemiology ; Drug Resistance, Viral ; Enzyme Inhibitors ; pharmacology ; Humans ; Influenza B virus ; drug effects ; enzymology ; genetics ; isolation & purification ; Influenza, Human ; epidemiology ; virology ; Microbial Sensitivity Tests ; Neuraminidase ; antagonists & inhibitors ; genetics ; metabolism ; Viral Proteins ; antagonists & inhibitors ; genetics ; metabolism

To analyze the antigenic and genetic characteristics of the influenza A (H3N2) virus in mainland China during the surveillance year of 2013-2014, the antigenic characteristics of H3N2 virus were analyzed using reference ferret anti-sera. The nucleotide sequences of the viruses were determined by Sanger dideoxy sequencing, phylogenetic trees were constructed with the neighbor-joining method, and the genetic characteristics of the viruses were determined in comparison to current vaccine strains. The results showed that most of the H3N2 viruses were antigenically closely related to the A/Victoria/361/2011 vaccine strain cell-propagated prototype virus (99.6%). Using the A/Texas/50/2012 egg isolate as the reference antigen, 15.1% of the viruses were found to be closely antigenically related to it, while 11.9% of strains were closely antigenically related to the egg-propagated epidemic strain, A/Shanghai-Changning/1507/2012. Phylogenetic analysis of HA genes indicated that the A(H3N2) viruses in this surveillance year were in the same clade, but no drug resistant mutation was identified in the NA genes. During the 2013-2014 influenza surveillance year, no significant genetic change was detected in either the HA or NA genes of the A(H3N2) viruses, while significant mutations were found in egg isolates resulting from their adaptation during propagation in eggs. The antigenic and genetic changes should be investigated in a timely manner to enable the selection of an appropriate vaccine strain in China.
Animals ; Antigenic Variation ; Base Sequence ; Chick Embryo ; China ; Genetic Variation ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; immunology ; Humans ; Influenza A Virus, H3N2 Subtype ; genetics ; immunology ; isolation & purification ; Influenza, Human ; virology ; Molecular Sequence Data ; Mutation ; Phylogeny