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 explore the induced effects of colchicine in different concentration and times on Foeniculum vulgare polyploidy.Methods Seed germination rate and mutation rate,morphology of radicle induced mutants,chromosome number,tissue structure,and content and component of essential oil,which induced by colchicine in different concentiation and times were investigaled using the method of soaking seeds.Results The results showed that 0.13% of colchicine concentration and 24 h inducing time had the best induction on F.vulgare polyploidy.Compared to the control,the radicle of mutant was thicker,the chromosome number increased clearly,and the cell number in radicle manifolded distinctly.Among the four main components of essential oil,the contents of Dill apiol in anamorphosis radicle was a little lower than that of the control,but the contents of limonene,(E)-anethole,and camphene in anamorphosis radicle were all remarkably higher than that of the control after induced by colchicine.ConclusionThe content of main essential oil components in fennel mutant induced by colchicine is remarkably enhanced.The study provides the theoretical basis for the breeding of F.vulgare new varieties of high oil content.

Objective To evaluate the effect of acupuncture point stimulation on the urodynamics of spinal cord injury patients.Methods Sixty spinal cord injury cases were divided into a research group and a comparison group.Both groups were given bladder training, but the research group also received acupuncture point stimulation.The subjects' maximum cystometric capacity, maximum detrusor pressure and residual urine were measured, along with renal function and any urinary tract infections.The scale of activity of their daily lives was compared before and 3 months and 6 months after the treatment.Results There were no statistically significant differences between the groups before the treatment.There were statistically significant differences in maximum cystometric capacity, maximum detrusor pressure, residual urine and Barthel index (BI) after 3 and 6 months of treatment.In the research group, maximum detrusor pressure, residual urine and BI scores had all improved after 6 months compared with the 3 month values.In the comparison group only the BI score had improved significantly between 3 and 6 months, and this was not reflected in a significant change in the scale of activity in daily life.After 3 months, only the average BI differed significantly between the two groups.After 6 months all indexes except the BI and maximum cystometric capacity differed significantly.There were also significant differences between the groups in reflex voiding, percussion voiding, and abdominal pressure voiding.Conclusions Acupuncture point stimulation can improve the bladder function of spinal cord injury patients.It can also decrease the incidence of urinary tract infection and the possibility of renal dysfunction.

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

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.

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

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.

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