Objective To construct a reverse genetic platform for influenza B virus and to rescue influenza B virus.Methods Eight plasmids carrying the gene segments of B/Florida/4/2006 virus were constructed by using the bidirectional promoter vector pHW2000.293T cells were co-cultured with MadinDarby canine kidney (MDCK) cells and then transfected with the eight plasmids.The supernatants of cell culture and cell debris were collected after transfection and then injected into embryonated chicken eggs and MDCK cells for rescuing the influenza B virus strains.Results This reverse genetic system could be used for the preparation of reassortant influenza B virus strains.The titers of hemagglutination units of the rescued virus achieved 128-256/50μl.Most of the reassortant virus particles were spherical under electron microscope.Conclusion The pHW2000 reverse genetic system could be used for the rescue of influenza B virus.Moreover,it could also be used for the construction of influenza B virus with specific mutations for further in vestigation on the characteristics of influenza B virus and the construction of vaccine strain.

Since the first outbreak of avian influenza A(H7N9) virus in humans was identified in 2013, there have been five seasonal epidemics observed in China. An earlier start and a steep increase in the number of humans infected with H7N9 virus was observed between September and December 2016, raising great public concern in domestic and international societies. The epidemiological characteristics of the recently reported confirmed H7N9 cases were analysed. The results suggested that although more cases were reported recently, most cases in the fifth epidemic were still highly sporadically distributed without any epidemiology links; the main characteristics remained unchanged and the genetic characteristics of virus strains that were isolated in this epidemic remained similar to earlier epidemics. Interventions included live poultry market closures in several cities that reported more H7N9 cases recently.

Objective: To isolate the cross-reactive antibodies against hemagglutinin of influenza virus and identify its biological function. Methods: The antibodies gene reservoir of cross-reactive and H5N1 pseudotype particles neutralizing B cell circulating in peripheral blood of a human H5N1 case was recovered by in vitro B cell culture, screening, RT-PCR and expression vector cloning techniques. The Ab gene pairing was screened by transient transfection of human kidney 293T cells and detected using ELISA and neutralization test. The heterosubtypic antibodies were prepared and characterized. Results: We discovered the VH1-2-based heterosubtypic antibodies from two B cell lineages could neutralize GX-H5N1 pseudotype particles and have broader binding with Group 1 (including H1, H5, H6 and H9) and H7 subtype. Conclusions Cross-reactive antibodies can be induced by H5N1 infection.

Objective Assess and determine inactivation effect of heat,.ultraviolet (UV) light and three disinfectants against human infected H9N2 avian influenza virus in laboratory.Methods Suspension containing with 1010.67 TCID50/ml viral was exposed to 50 ℃,56 ℃,60 ℃,65 ℃ for 10 to 60 minutes and UV every 10 interval minutes from 10 to 80 minutes.The residual viruses after physical treatment were determined through half of tissue culture infective dose (TCID50) with MDCK cells and calculated by Reed-Muench method.Suspension with 1010.37EID50/ml quantitative virus was applied to equal volume of 10％ 84 sanitizer,75％ ethanol,1％ Virkon solution and incubated for 1 minute to 15 minutes respectively.The residual viral activity would be evaluated by inoculating in SPF chicken embryo.When the virus titer dropped by 4 lgTCID50/ml or virus in chicken embryo culture was observed to be negative,the physical and chemical treatment was considered effective.Results Human infected H9N2 avian influenza virus titer decreased by 4.02 lgTCID50 at 56 ℃ for 15 minutes,and after 30 minutes at 56 ℃ or 10 minutes at 60 ℃/65 ℃,the post-viral titer would decline below the detection level.20 minutes of UV irradiation would lead to a 5.67 log reduction,and after 70 minutes lighted,the virus titer fell below the detection level.Virus proliferation was not detected after 3 minutes of disinfection with 10％ 84 sanitizer,75％ ethanol and 1％ Virkon.Conclusions We should note that it is necessary to meet the specific condition to effectively inactivate the human infected H9N2 avian influenza virus.Our study provides an experimental basis for the biosafety operation of human infected H9N2 avian influenza virus.

Objective To investigate the effect of postoperative analgesia nursing on the comfort degree of laparotomy patients in hepatobiliary surgery department.Methods A total of 86 laparotomy patients in our department were randomly divided into observation group and control group,receiving postoperative analgesia nursing and routine nursing,respectively.And postoperative analgesia and postoperative comfort were compared.Results The postoperative pain degree in the observation group was less than that in the control group,the incidence of incomplete analgesia was lower than that in the control group,pain call frequency in the operation day,1 day after operation,and 2 day after operation was lower than that in the control group,the difference was statistically significant (P ＜0.05).Comfort of physiological,psychological,social and cultural aspects in the observation group were higher than that in the control group,nursing satisfaction was higher than the control group,the difference was statistically significant (P ＜ 0.05).Conclusion Postoperative analgesia nursing can significantly reduce degree of pain of laparotomy patients in hepatobiliary surgery department,and improve the postoperative comfort and nursing satisfaction.

Objective To investigate the effect of postoperative analgesia nursing on the comfort degree of laparotomy patients in hepatobiliary surgery department.Methods A total of 86 laparotomy patients in our department were randomly divided into observation group and control group,receiving postoperative analgesia nursing and routine nursing,respectively.And postoperative analgesia and postoperative comfort were compared.Results The postoperative pain degree in the observation group was less than that in the control group,the incidence of incomplete analgesia was lower than that in the control group,pain call frequency in the operation day,1 day after operation,and 2 day after operation was lower than that in the control group,the difference was statistically significant (P ＜0.05).Comfort of physiological,psychological,social and cultural aspects in the observation group were higher than that in the control group,nursing satisfaction was higher than the control group,the difference was statistically significant (P ＜ 0.05).Conclusion Postoperative analgesia nursing can significantly reduce degree of pain of laparotomy patients in hepatobiliary surgery department,and improve the postoperative comfort and nursing satisfaction.

Objective: To develop the monoclonal antibody (mAb) against neuraminidase of H7N9 subtype influenza A virus and identify its biological function. Methods: Female 8 week-old BALB/c mice were immunized and the splenocytes of the mice were fused with Sp2/0 myeloma cells. Indirect ELISA was used to screen hybridoma and the positive clones were subject to be subcloned. Positive clones were identified and the monoclonal antibodies(mAbs) were obtained by purifying the ascetic fluid of mice injected with the hybridoma. The NA-binding as well as neuraminidase-inhibition activity of these mAbs were determined. Results: Three mAbs against neuraminidase of H7N9 subtype influenza A virus, 1G8, 3C4 and 4E8, were obtained. They demonstrated different epitop-recognizing. 3C4 and 4E8 exhibited neuraminidase inhibitory activity, with a IC₅₀ of 1.45 μg/ml and 8.65 μg/ml, respectively. Conclusions The results suggested that mAbs specific to neuraminidase of H7N9 subtype influenza A virus were developed, providing an useful tool in control and preventing the novel H7N9 influenza A virus.

Objective To evaluate the cells for producing vaccine of avian influenza H10 subtype, the growth characteristics of influenza H10 subtype reassortant viruses in different cells ( MDCK and Vero) were investigated.Methods Reassortant viruses, RG-H10N1(7 +1) and RG-H10N8(6 +2), between wild-type virus A/Jiangxi-donghu/346/2013 ( JXH10N8 ) and high-yielding virus A/Puerto Rico/8/34 ( PR8) were constructed with reverse genetic system.Viruses were propagated in SPF embryonated chicken eggs.The growth characteristics of the two reassortant viruses were compared after inoculating MDCK and Vero cells respectively, with RG-PR8 as the control.Viral growth characteristics were studied at different MOI in MDCK cells.Results All viruses could be detected TCID50 in MDCK cells.RG-PR8 and RG-H10N1could be detected TCID50 in Vero cells but not RG-H10N8.There were no significant difference in HA titer between the two reassortant viruses at the same MOI, but both reassortant viruses exhibited lower HA titers than that of PR8 in MDCK cells.Conclusion Both influenza H10 subtype reassortant viruses grew better in MDCK cells.MDCK cells are more sensitive to the influenza H10 reassortant viruses, and NA from different subtypes could affect the grow capability of reassortant viruses in Vero cells.

Influenza is an acute respiratory infection that seriously harms the world and public health. Because influenza viruses are prone to mutations and difficult to predict, the World Health Organization has been promoting global continuous strengthening of influenza surveillance to monitor the level of influenza activity and epidemic trends in real time. Establishing baselines and thresholds for influenza epidemic helps to gauge the start and severity of influenza seasons. At present, there are various methods for calculating baseline and threshold, such as annual median value, percentile approach, moving epidemic method, and control chart method. This paper will summarize the methods of establishing influenza baseline or threshold at home and abroad, and hope to provide reference for the establishment of baseline or threshold of influenza in China.

Influenza is an acute respiratory infection that seriously harms the world and public health. Because influenza viruses are prone to mutations and difficult to predict, the World Health Organization has been promoting global continuous strengthening of influenza surveillance to monitor the level of influenza activity and epidemic trends in real time. Establishing baselines and thresholds for influenza epidemic helps to gauge the start and severity of influenza seasons. At present, there are various methods for calculating baseline and threshold, such as annual median value, percentile approach, moving epidemic method, and control chart method. This paper will summarize the methods of establishing influenza baseline or threshold at home and abroad, and hope to provide reference for the establishment of baseline or threshold of influenza in China.