Due to the insufficient supply of embryonated chicken eggs,the preparation of large quantities of inactivated influenza vaccines will require an alternative virus culture system after the emergence or reemergence of a...Due to the insufficient supply of embryonated chicken eggs,the preparation of large quantities of inactivated influenza vaccines will require an alternative virus culture system after the emergence or reemergence of a pandemic influenza virus.The Vero cell is one of the ideal options since it was used for producing many kinds of human vaccines.However,most of the influenza viruses can not grow well in Vero cells.To develop a new influenza vaccine with Vero cells as a substrate,the virus needs to adapt to this cell substrate to maintain high growth characteristics.By serial passages in Vero cells,the B/Yunnan/2/2005va(B)strain was successfully adapted to Vero cells,with the hemagglutination titer(HAT)of the virus reaching 1:512.The high growth characteristic of this strain is stable up to 21 passages.The strain was identified by hemagglutination inhibition (HAI)test and sequencing respectively;the HA1 gene sequence of the virus was cloned and analyzed.The screening and establishment of high growth B virus provides an important tool for influenza vaccine production in Vero cells.展开更多
Background:Influenza B virus can cause epidemics with high pathogenicity, so it poses a serious threat to public health. A feature representation algorithm is proposed in this paper to identify the pathogenicity pheno...Background:Influenza B virus can cause epidemics with high pathogenicity, so it poses a serious threat to public health. A feature representation algorithm is proposed in this paper to identify the pathogenicity phenotype of influenza B virus.Methods:The dataset included all 11 influenza virus proteins encoded in eight genome segments of 1724 strains. Two types of features were hierarchically used to build the prediction model. Amino acid features were directly delivered from 67 feature descriptors and input into the random forest classifier to output informative features about the class label and probabilistic prediction. The sequential forward search strategy was used to optimize the informative features. The final features for each strain had low dimensions and included knowledge from different perspectives, which were used to build the machine learning model for pathogenicity identification.Results:The 40 signature positions were achieved by entropy screening. Mutations at position 135 of the hemagglutinin protein had the highest entropy value (1.06). After the informative features were directly generated from the 67 random forest models, the dimensions for class and probabilistic features were optimized as 4 and 3, respectively. The optimal class features had a maximum accuracy of 94.2% and a maximum Matthews correlation coefficient of 88.4%, while the optimal probabilistic features had a maximum accuracy of 94.1% and a maximum Matthews correlation coefficient of 88.2%. The optimized features outperformed the original informative features and amino acid features from individual descriptors. The sequential forward search strategy had better performance than the classical ensemble method.Conclusions:The optimized informative features had the best performance and were used to build a predictive model so as to identify the phenotype of influenza B virus with high pathogenicity and provide early risk warning for disease control.展开更多
BACKGROUND Among the various types and causes of mesenteric ischemia,superior mesenteric vein(SMV)thrombosis is a rare and ambiguous disease.If a patient presents with SMV thrombosis,past medical history should be rev...BACKGROUND Among the various types and causes of mesenteric ischemia,superior mesenteric vein(SMV)thrombosis is a rare and ambiguous disease.If a patient presents with SMV thrombosis,past medical history should be reviewed,and the patient should be screened for underlying disease.SMV thrombosis may also occur due to systemic infection.In this report,we describe a case of SMV thrombosis complicated by influenza B infection.CASE SUMMARY A 64-year-old male visited the hospital with general weakness,muscle aches,fever,and abdominal pain.The patient underwent computed tomography(CT)and was diagnosed with SMV thrombosis.Since the patient’s muscle pain and fever could not be explained by the SMV thrombosis,the clinician performed a test for influenza,which produced a positive result for influenza B.The patient had a thrombus in the SMV only,with no invasion of the portal or splenic veins,and was clinically stable.Anticoagulation treatment was prescribed without surgery or other procedures.The follow-up CT scan showed improvement,and the patient was subsequently discharged with continued oral anticoagulant treatment.CONCLUSION This case provides evidence that influenza may be a possible risk factor for SMV thrombosis.If unexplained abdominal pain is accompanied by an influenza infection,examination of an abdominal CT scan may be necessary to screen for possible SMV thrombosis.展开更多
Background Military recruits are at a higher risk of acute respiratory disease(ARD) and the causative agents might change over time, which needs to be investigated. Methods The nasopharyngeal swabs and blood samples w...Background Military recruits are at a higher risk of acute respiratory disease(ARD) and the causative agents might change over time, which needs to be investigated. Methods The nasopharyngeal swabs and blood samples were consecutively collected from conscripts for three years in a military training center. The real-time fluorescent quantitative PCR assays were conducted for 15 species of common respiratory pathogens; the serum anti-Legionella pneumophila antibodies were detected by indirect immunofluorescence(IIF) assay, and serum anti-Microplasma pneumoniae antibodies, serum anti-influenza B virus and anti-influenza A virus-Ig M and Ig G were detected by ELISA. Results The prevalences of ARD were 59.3%(108/182) in 2008, 23.3%(50/215) in 2009,and 19.6%(40/204) in 2010. Among the patients with ARD from 2008 to 2010, the influenza B virus infection accounted for 45.4%, 30.0% and 55.0%, and seasonal influenza A virus infection for 8.3%, 8.0% and 5.0%, respectively; the positive rates of serum anti-Legionella pneumophila and anti-Microplasma pneumoniae antibodies in recruits was lower than 10% each year respectively in the three years without diagnostic significance. Conclusion The early appropriate diagnosis and treatment of ARD in military personnel will ensure the power strength of armed forces.展开更多
目的了解2010-2015年湖北省乙型流感病毒流行分布和基因进化情况。方法通过测序和全球流感共享数据库(global initiative on sharing all influenza data,GISAID)获得2010-2015年湖北省乙型流感病毒血凝素(hemagglutinin,HA)和神经氨酸...目的了解2010-2015年湖北省乙型流感病毒流行分布和基因进化情况。方法通过测序和全球流感共享数据库(global initiative on sharing all influenza data,GISAID)获得2010-2015年湖北省乙型流感病毒血凝素(hemagglutinin,HA)和神经氨酸酶(neuramidinase,NA)氨基酸序列,分别对其进行系统进化树、氨基酸突变位点和三维建模分析,结合同期病毒分离株流行分布,分析重配株基因进化与病毒流行分布间的关系。结果 2010-2015年湖北省乙型流感病毒存在系内重配和系间重配,首例重配株出现后,该病毒都会形成较大流行。同期病毒在HA四个主要抗原表位上发现的突变位点有:N116K、N129S、A146T、K162R和N197S,在NA上发现了神经氨酸酶活性突变位点D197N,三维建模表明该位点并非直接与底物或抑制物接触。结论 2010-2015年湖北省乙型流感病毒的流行与该病毒的基因进化关系密切,监测该病毒抗原表位突变位点和耐药突变位点有助于深入分析其进化特性。展开更多
基金National"863 Project"(2006AA02Z409)National health project(200802023)Yunnan sciences and technology cooperation(2006XY29)
文摘Due to the insufficient supply of embryonated chicken eggs,the preparation of large quantities of inactivated influenza vaccines will require an alternative virus culture system after the emergence or reemergence of a pandemic influenza virus.The Vero cell is one of the ideal options since it was used for producing many kinds of human vaccines.However,most of the influenza viruses can not grow well in Vero cells.To develop a new influenza vaccine with Vero cells as a substrate,the virus needs to adapt to this cell substrate to maintain high growth characteristics.By serial passages in Vero cells,the B/Yunnan/2/2005va(B)strain was successfully adapted to Vero cells,with the hemagglutination titer(HAT)of the virus reaching 1:512.The high growth characteristic of this strain is stable up to 21 passages.The strain was identified by hemagglutination inhibition (HAI)test and sequencing respectively;the HA1 gene sequence of the virus was cloned and analyzed.The screening and establishment of high growth B virus provides an important tool for influenza vaccine production in Vero cells.
文摘Background:Influenza B virus can cause epidemics with high pathogenicity, so it poses a serious threat to public health. A feature representation algorithm is proposed in this paper to identify the pathogenicity phenotype of influenza B virus.Methods:The dataset included all 11 influenza virus proteins encoded in eight genome segments of 1724 strains. Two types of features were hierarchically used to build the prediction model. Amino acid features were directly delivered from 67 feature descriptors and input into the random forest classifier to output informative features about the class label and probabilistic prediction. The sequential forward search strategy was used to optimize the informative features. The final features for each strain had low dimensions and included knowledge from different perspectives, which were used to build the machine learning model for pathogenicity identification.Results:The 40 signature positions were achieved by entropy screening. Mutations at position 135 of the hemagglutinin protein had the highest entropy value (1.06). After the informative features were directly generated from the 67 random forest models, the dimensions for class and probabilistic features were optimized as 4 and 3, respectively. The optimal class features had a maximum accuracy of 94.2% and a maximum Matthews correlation coefficient of 88.4%, while the optimal probabilistic features had a maximum accuracy of 94.1% and a maximum Matthews correlation coefficient of 88.2%. The optimized features outperformed the original informative features and amino acid features from individual descriptors. The sequential forward search strategy had better performance than the classical ensemble method.Conclusions:The optimized informative features had the best performance and were used to build a predictive model so as to identify the phenotype of influenza B virus with high pathogenicity and provide early risk warning for disease control.
文摘BACKGROUND Among the various types and causes of mesenteric ischemia,superior mesenteric vein(SMV)thrombosis is a rare and ambiguous disease.If a patient presents with SMV thrombosis,past medical history should be reviewed,and the patient should be screened for underlying disease.SMV thrombosis may also occur due to systemic infection.In this report,we describe a case of SMV thrombosis complicated by influenza B infection.CASE SUMMARY A 64-year-old male visited the hospital with general weakness,muscle aches,fever,and abdominal pain.The patient underwent computed tomography(CT)and was diagnosed with SMV thrombosis.Since the patient’s muscle pain and fever could not be explained by the SMV thrombosis,the clinician performed a test for influenza,which produced a positive result for influenza B.The patient had a thrombus in the SMV only,with no invasion of the portal or splenic veins,and was clinically stable.Anticoagulation treatment was prescribed without surgery or other procedures.The follow-up CT scan showed improvement,and the patient was subsequently discharged with continued oral anticoagulant treatment.CONCLUSION This case provides evidence that influenza may be a possible risk factor for SMV thrombosis.If unexplained abdominal pain is accompanied by an influenza infection,examination of an abdominal CT scan may be necessary to screen for possible SMV thrombosis.
基金supported for causative pathogen survey of ARD in conscripts as a medical science key project of the People’s Liberation Army(grant number 08G021)The funders had no role in the study design,data collection and analysis,decision to publish,or preparation of the manuscript
文摘Background Military recruits are at a higher risk of acute respiratory disease(ARD) and the causative agents might change over time, which needs to be investigated. Methods The nasopharyngeal swabs and blood samples were consecutively collected from conscripts for three years in a military training center. The real-time fluorescent quantitative PCR assays were conducted for 15 species of common respiratory pathogens; the serum anti-Legionella pneumophila antibodies were detected by indirect immunofluorescence(IIF) assay, and serum anti-Microplasma pneumoniae antibodies, serum anti-influenza B virus and anti-influenza A virus-Ig M and Ig G were detected by ELISA. Results The prevalences of ARD were 59.3%(108/182) in 2008, 23.3%(50/215) in 2009,and 19.6%(40/204) in 2010. Among the patients with ARD from 2008 to 2010, the influenza B virus infection accounted for 45.4%, 30.0% and 55.0%, and seasonal influenza A virus infection for 8.3%, 8.0% and 5.0%, respectively; the positive rates of serum anti-Legionella pneumophila and anti-Microplasma pneumoniae antibodies in recruits was lower than 10% each year respectively in the three years without diagnostic significance. Conclusion The early appropriate diagnosis and treatment of ARD in military personnel will ensure the power strength of armed forces.
文摘目的了解2010-2015年湖北省乙型流感病毒流行分布和基因进化情况。方法通过测序和全球流感共享数据库(global initiative on sharing all influenza data,GISAID)获得2010-2015年湖北省乙型流感病毒血凝素(hemagglutinin,HA)和神经氨酸酶(neuramidinase,NA)氨基酸序列,分别对其进行系统进化树、氨基酸突变位点和三维建模分析,结合同期病毒分离株流行分布,分析重配株基因进化与病毒流行分布间的关系。结果 2010-2015年湖北省乙型流感病毒存在系内重配和系间重配,首例重配株出现后,该病毒都会形成较大流行。同期病毒在HA四个主要抗原表位上发现的突变位点有:N116K、N129S、A146T、K162R和N197S,在NA上发现了神经氨酸酶活性突变位点D197N,三维建模表明该位点并非直接与底物或抑制物接触。结论 2010-2015年湖北省乙型流感病毒的流行与该病毒的基因进化关系密切,监测该病毒抗原表位突变位点和耐药突变位点有助于深入分析其进化特性。
