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 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: 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 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.

To assess relationships between xanthine oxidase (XOD) and nephropathogenic infectious bronchitis virus (NIBV) infection, 240 growing layers (35 days old) were randomly divided into two groups (infected and control) of 120 chickens each. Each chicken in the control and infected group was intranasally inoculated with 0.2 mL sterile physiological saline and virus, respectively, after which serum antioxidant parameters and renal XOD mRNA expression in growing layers were evaluated at 8, 15 and 22 days post-inoculation (dpi). The results showed that serum glutathione peroxidase and superoxide dismutase activities in the infected group were significantly lower than in the control group at 8 and 15 dpi (p < 0.01), while serum malondialdehyde concentrations were significantly higher (p < 0.01). The serum uric acid was significantly higher than that of the control group at 15 dpi (p < 0.01). In addition, the kidney mRNA transcript level and serum activity of XOD in the infected group was significantly higher than that of the control group at 8, 15 and 22 dpi (p < 0.05). The results indicated that NIBV infection could cause the increases of renal XOD gene transcription and serum XOD activity, leading to hyperuricemia and reduction of antioxidants in the body.
Antioxidants ; Chickens ; Glutathione Peroxidase ; Hyperuricemia ; Infectious bronchitis virus* ; Kidney ; Malondialdehyde ; RNA, Messenger* ; Superoxide Dismutase ; Uric Acid ; Xanthine Oxidase* ; Xanthine*

OBJECTIVETo analyze the susceptibility of influenza A (H3N2) viruses to neuraminidase inhibitors during 2011-2012 in Mainland China.

METHODSAll the tested viruses were obtained from the Chinese National Influenza Surveillance Network, which covers 31 provinces in mainland China, including 408 network laboratories and 554 sentinel hospitals. In total 1 903 viruses were selected with isolation date from January 1, 2011 to December 31, 2012 in Mainland China, among these viruses, 721 were confirmed to be influenza A (H3N2) virus by Chinese National Influenza Center and tested for the susceptibility to oseltamivir and zanamivir using chemiluminescence-based assay. The neuraminidase inhibitor sensitive reference virus A/Washington/01/2007 (119E) and oseltamivir resistant virus A/Texas/12/2007 (E119V) were used as control in this study. The t -test was used to compare the difference of NAI susceptibility of viruses isolated from different years.

RESULTSThe half maximal inhibitory concentration (IC₅₀) of A/Washington/01/2007 for oseltamivir and zanamivir was (0.10 ± 0.02) and (0.30 ± 0.05) nmol/L, respectively. The IC₅₀ of A/Texas/12/2007 for oseltamivir and zanamivir was (4.27 ± 1.60) and (0.20 ± 0.03) nmol/L, respectively. Among the 721 influenza A (H3N2) viruses, 132 influenza A (H3N2) viruses were isolated in 2011 and 589 influenza A (H3N2) viruses were isolated in 2012. The IC50 for oseltamivir ranged from 0.04 to 0.62 nmol/L for viruses isolated in 2011 and ranged from 0.02 to 0.95 nmol/L for viruses in 2012, and the IC₅₀ of all the viruses tested was within 10-fold IC₅₀ (1.0 nmol/L) of the neuraminidase inhibitor sensitive reference virus A/Washington/01/2007. The IC50 of zanamivir ranged from 0.12 to 0.80 nmol/L for viruses in 2011 and ranged from 0.04 to 0.72 nmol/L for viruses in 2012, and was within 10-fold IC₅₀ (3.0 nmol/L) of the neuraminidase inhibitor sensitive reference virus A/Washington/01/2007.

CONCLUSIONThe influenza A(H3N2) viruses isolated during 2011-2012 in Mainland China were tested to be sensitive to oseltamivir and zanamivir.

Antiviral Agents ; China ; Drug Resistance, Viral ; Enzyme Inhibitors ; Epidemiological Monitoring ; Humans ; Influenza A Virus, H3N2 Subtype ; Influenza, Human ; Neuraminidase ; Oseltamivir ; Zanamivir