Objective To investigate the possibility of using well-differentiated human airway epithelial cells (HAE) to isolate and identify human influenza A virus from a stale respiratory tract specimen.Methods The stale specimen used in this study was a nasopharyngeal swab specimen collected from a patient with unexplained pneumonia in Qinghai in 2010.It was positive for influenza A virus (H3N2) RNA, but negative for hemagglutination.Equal amount of the specimen was inoculated on HAE and on Madin-Darby canine kidney (MDCK) cells for virus isolation and passage.Cytopathic effects were observed daily after inoculation.Hemagglutination inhibition test was performed at every passage.Electron microscope was used to observe viral morphology.Viral genome was sequenced, followed by molecular evolutionary analysis.Results No progeny virus was isolated in MDCK cells, while a influenza A virus subtype H3N2 strain [A/Qinghai/178/2010(H3N2)] was isolated in HAE with a typical morphology and cytopathic effect of influenza A infection.The hemagglutination inhibition activity was 1∶16.Results of the molecular evolutionary analysis of viral genome showed that the influenza A virus (H3N2) strain was highly homologous to the A/Nanjing/1655/2010(H3N2) strain, which was isolated during the 2010 influenza pandemic in Nanjing.Conclusion HAE can be used for isolation and identification of virus from stale respiratory tract specimens.It is more sensitive than MDCK cells with regard to human influenza virus isolation.

Objective To investigate the distribution of peripheral arterial stiffness,endothelial function and their correlations with cardiovascular risk factors in the 7-17 year-olds.Methods Normal weight and obese subjects aged 7-17 years with completed data on questionnaires,anthropometric and blood biochemical tests,were recruited from a cross-sectional population-based study on childhood hypertension in Minhang district of Shanghai.Automatic waveform analyzer (BP-203RPE-I) and Endopat 2000 were used to measure the arterial stiffness.Endothelial function with brachial-ankle pulse wave velocity (baPWV) and reactive hyperemia index (RHI) were recorded.BaPWV and RHI were standardized by age.Skewed biochemical variables were log transformed.Linear correlation analysis was performed to observe association between baPWV,RHI and other measured variables.Results A total of 452 normal-weight and 94 obese subjects were recruited,including 299 males.Data showed that baPWV and RHI increased with age in normal weight subjects (r=0.33,P＜0.01;r=0.36,P＜0.01).Results from Linear correlation analysis revealed that baPWV was positively correlated with BMI (r=0.13,P=0.002),systolic blood pressure (SBP) (r=0.20,P＜0.01),diastolic blood pressure (DBP) (r=0.27,P＜0.01),triglycerides (TG) (r=0.11,P=0.010),insulin (r=0.21,P=0.004) and the HOMA insulin resistance index (r=0.21,P=0.005),but negatively correlated with high-density lipoprotein cholesterol (r=-0.09,P=0.039).RH1 was positively correlated with BMI (r=0.10,P=0.018) but negatively correlated with DBP (r=-0.10,P=0.016).Males had higher baPWVs than females (P=0.04).However,RHI did not differ between genders.Conclusions The fact that baPWV and RHI increased along with age,indicated that the arterial stiffness and endothelial function continued to develop in normal weight childhood and adolescence.Arterial stiffness was correlated with cardiovascular risk-related parameters whereas endothelial function was not.BaPWV might be more sensitive in evaluating the cardiovascular risk in children and adolescents than RHI did.