Reversed phase monolithic analytical columns for the determination of HA1 subunit of influenza virus haemagglutinin

Monoliths are chromatographic stationary phases, which were specially designed for efficient purification of large biomolecules, like proteins, viruses and DNA. In this work, the small scale monolithic butyl (C4) and styrene-divinyl benzene (SDVB) columns were applied for reversed phase analyses of various degraded influenza viruses. The binding of the HA1 subunit of haemagglutinin to the monolithic columns was confirmed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and the Western blot. The working linear range was determined as 1.60 × 10¹⁰ viral particles/mL to at least 1.64 × 10¹¹ viral particles/mL, the limit of detection was found to be 2.56 × 10⁹ virus particles/mL and the limit of quantification was 5.12 × 10⁹ virus particles/mL. The analytical HPLC method developed with the H1N1 virus was also applicable for the analytics of the HA1 subunit of H3N2 influenza virus and the influenza B virus.     

Synthesis of the 6-6-6 tricyclic skeleton of the anti-influenza A diterpene wickerol A

A five-step synthesis of the 6-6-6 tricyclic skeleton of the diterpene wickerol A is described. The synthesis features a diastereoselective d-proline-mediated Robinson annulation and N-heterocyclic carbene-catalyzed Stetter reaction as key transformations to give the tricyclic carbon skeleton of this promising anti-influenza A natural product.     

A meta-analysis of tumor necrosis factor (TNF) gene polymorphism and susceptibility to influenza A (H1N1)

PurposeThe aim of the study was to comprehensively evaluate the associations between tumor necrosis factor (TNF) gene polymorphism and influenza A (H1N1) susceptibility.MethodsThe relevant studies were identified through a search of PubMed, Embase, and Cochrane library database until February 29, 2020, without language restrictions. Two independent reviewers extracted the data, and any discrepancies were resolved by consensus. The quality of the eligible article was evaluated by Newcastle-Ottawa Quality Assessment Scale (NOS). Egger’s test was applied to evaluate publication bias. All these analyses were performed using Stata15.1 software.ResultsA total of 5 studies with 474 cases and 805 controls were included. The results of meta-analysis showed that there were statistically significant for rs361525 in allelic model (A vs. G) [OR = 2.46 (1.10, 5.52)] and for rs1800750 in dominant model (AA + GA vs. GG) [OR = 2.42 (1.24, 4.71)] in cases vs. controls. Furthermore, subgroup analysis for race showed that for rs361525 in allelic model (A vs. G), there were significant differences for Caucasian [OR = 3.64 (1.18, 11.23)] and no significant difference for Mexican [OR = 2.25 (0.82, 6.13)] in cases vs. controls. There was publication bias for rs361525 in dominant model (AA + GA vs. GG, p = 0.042) and rs1800629 in recessive model (AA vs. GG + GA, p < 0.001).ConclusionsCaucasian with A site mutation of -238TNF G/A (rs361525) was more susceptible to influenza A (H1N1).The -376 dominant model AA + GA of TNF genes was associated with the susceptibility to influenza A (H1N1). However, more studies with large sample size are needed to confirm the results.     

Numerical study of an influenza epidemic model with diffusion

A diffusive epidemic model is investigated with a view to describe the transmission of influenza as an epidemic. The equations are solved numerically using the splitting method under different initial distribution of population density. It is shown that the initial population distribution and diffusion play an important role for spread of disease. It is also shown that interventions (medical and nonmedical) significantly slow down the spread of disease. Stability of equilibria of the numerical solutions are also established.     

Modeling influenza progression within a continuous-attribute heterogeneous population

We consider three attributes of an individual that are critical in determining the temporal dynamics of pandemic influenza: social activity, proneness to infection, and proneness to shed virus and spread infection. These attributes differ by individual, resulting in a heterogeneous population. We develop discrete-time models that depict the evolution of the disease in the presence of such population heterogeneity. For every individual, the value for each of the three describing attributes is viewed as an experimental value of a continuous random variable. The methodology is simple yet general, extending more traditional discrete compartmental models that depict population heterogeneity. Illustrative numerical examples show how individuals who have much larger-than-average values for one or more of the attributes drive the influenza wave, especially in the early generations of the pandemic. This heterogeneity-driven pandemic physics carries important policy implications. We conclude by using contact data in four European countries to demonstrate empirical uses of our model.     

基于荧光染料和氧化石墨烯同步荧光法同时检测多种流感病毒亚型

分别采用三种不同发射波长的荧光染料,通过共价偶联的方式分别标记三种流感病毒亚型H1N1、H5N1和H9N2的抗体,再利用氧化石墨烯猝灭所标记染料的荧光。当将荧光标记抗体和氧化石墨烯一并加入到流感病毒溶液中时,由于抗原和抗体之间的特异性相互作用,病毒会和抗体作用而使得氧化石墨烯远离荧光染料,染料的荧光得以恢复。通过恢复的荧光发射波长位置和荧光强度,可以定性和定量检测三种不同的流感病毒亚型。在最佳实验条件下,对三种流感病毒亚型H1N1、H5N1和H9N2进行同时检测,H1N1的检出限为0.48ng/mL,线性范围为1~18ng/mL;H5N1的检出限为0.46ng/mL,线性范围为1~18.5ng/mL;H9N2的检出限为0.42ng/mL,线性范围为1~16ng/mL。该方法具有较好的稳定性、重现性和灵敏度,可实现多个流感病毒亚型的分型和同时检测。     

单管高灵敏度等温扩增技术快速检测甲型H1N1流感病毒

建立了单管逆转录环介导等温扩增法(RT-LAMP)快速检测甲型H1N1流感病毒的方法.针对甲型H1N1流感病毒的M基因和HA基因的保守区,设计了两组特异性引物,分别用于筛选甲型流感病毒及鉴定甲型H1N1流感病毒.对反应体系中的关键因素进行优化,反应结果可直接通过浊度或者SYBR Green Ⅰ荧光进行判定.本方法最低可...     

Paper-based enzyme-free immunoassay for rapid detection and subtyping of influenza A H1N1 and H3N2 viruses

Development of rapid screening in the ambulatory environment is the most pressing needs for the control of spread of infectious disease. Despite there are many methods to detect the immunoassay results, quantitative measurement in rapid disease screening is still a great challenge for point-of-care applications. In this work, based on the internal structural protein, i.e., nucleoprotein (NP), and outer surface glycoproteins, i.e., H1 and H3, of the influenza viruses, specific and sensitive immunoassay on paper-based platform was evaluated and confirmed. Detection and subtyping of influenza A H1N1 and H3N2 viruses found in people were demonstrated by colorimetric paper-based sandwich immunoassay. Concentration-dependent response to influenza viruses was shown and the detection limits could achieve 2.7 × 10³ pfu/assay for H1 detection and 2.7 × 10⁴ pfu/assay for H3 detection, which are within the clinical relevant level. Moreover, detection of influenza virus from infected cell lysate and clinical samples was demonstrated to further confirm the reliability of the paper-based immunoassay. The use of paper for the development of diagnostic devices has the advantages of lightweight, ease-of-use, and low cost and paper-based immunoassay is appropriate to apply for rapid screening in point-of-care applications.     

禽流感病毒H5N1病毒颗粒中鸡胚宿主蛋白的质谱分析

在A型流感病毒等许多包膜病毒的病毒颗粒中,除包含病毒基因组编码的结构蛋白外,还包含来源于宿主细胞的多种蛋白。然而,在鸡胚内增殖的病毒颗粒所包含的宿主蛋白的种类尚不清楚。本研究采用20%～60%(w/w)蔗糖密度梯度离心法分离纯化了繁殖于鸡胚的流感病毒,并用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(Sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)结合质谱法对纯化的流感病毒颗粒进行了全面的蛋白质组学分析。结果表明,在病毒颗粒中,除包含9种病毒编码蛋白外,还发现了12种来源于鸡胚的蛋白,如膜联蛋白A2、肽酰脯氨酰顺反异构酶B、过氧化物酶1、磷酸甘油酸激酶、丙酮酸激酶肌组织异构酶等,以及2种细胞骨架蛋白(微管蛋白b-3和肌动蛋白)。