Preparation of a mask of traditional Chinese medicine and an experimental study of its effectiveness against the H1N1 influenza virus
0
Citation
0
Reference
20
Related Paper
Abstract:
Objectives To prepare a mask from extracts of Isatis leaf and root, filter a solution of influenza virus through it, and then detect viral activity in the filtrate in order to evaluate the mask's effectiveness against the influenza virus. Methods A solution of H1N1 influenza virus with a hemagglutination titer of 2-12 was filtered through the drug mask. After the filtrate was collected, the hemagglutination titer of the viral solution was determined by performing a hemagglutination test. Then the filtrate was inoculated into chick embryos. The hemagglutination test was performed with allantoic fluid collected after 48 h. Viral activity in the filtrate was analyzed via the hemagglutination titer and EID50. Results Compared to the unfiltered solution of influenza virus with a hemagglutination titer of 2-12, the hemagglutination titer of the filtrate was 2-3 (P0.01). The hemagglutination titer of allantoic liquid was 2-6 after inoculation with filtrate (P0.01). Compared to the unfiltered H1N1 solution with an EID50 of 10-4.95/0.1ml, the filtrate had an EID50 of 10-2.10/0.1ml (P0.01). Conclusion The influenza virus lost more than 93% of its infectivity after it was filtered through a mask made from extracts of Isatis leaf and root. This suggests that the drug mask could be used to prevent infection with the influenza virus.Keywords:
Hemagglutination assay
Infectivity
Cite
Anti-influenza virus activity of "Benovoair Concentrate".The different dilution of samples were mixed with the same quantity of 100 TCID50 virus at 37 degrees C for 30 minutes. Add suitable quantity mixture in wells containing cells. Every 3 wells were the same mode. Viruses control, cells control and samples control of different dilution were performed and set in the CO2 incubator at 37 degrees C. CPE was observed every day. When CPE appears in viruses control as "++++", stopped testing and performed the hemagglutination titration."Benovoair Concentrate" with dilution of 1:60, 1:120, 1:240 and 1:480 have 100% anti-influenza A and anti-influenza B activities. "Benovoair Concentrate" with dilution of 1:960 and 1:1920 have 25%-50% anti-influenza A and anti-influenza B activities.The test was the proof of anti-influenza virus activities which provided for the development of "Benovoair Concentrate".
Dilution
Hemagglutination assay
Positive control
Negative control
Cite
Citations (0)
The hemagglutination test is a tool utilized to screen cell culture supernatant liquid collected from embryonated chicken eggs for hemagglutinating operators, such as type A flu. The HA is not an recognizable proof test, as other specialists too have hemagglutinating properties.
Embryonated
Hemagglutination assay
Hemagglutination tests
Cite
Citations (0)
The hemagglutination-inhibition (HAI) assay is a critical component for measurement of immunogenicity in influenza vaccine development. It is unknown if the results can be influenced by sample type and anticoagulants. The purpose of this study was to evaluate the influence of different sample collection methods, in particular different anticoagulants, and choice of plasma or serum, on influenza virus serological assays. Blood samples from thirty donors previously immunized against influenza viruses were collected using six different types of blood collection tubes, two of which collect serum and four of which contain various anticoagulants for collecting plasma. Serum: (1) serum separator tubes (SST); and (2) Plus Plastic serum "red-top serum" tubes. Plasma: (3) spray-coated K2 ethylenediaminetetraacetic acid (EDTA) tubes: (4) Sodium Heparin tubes; (5) Citrate tubes with 3.2% sodium citrate solution; and (6) Glass Blood Collection tubes with acid citrate dextrose. Samples were tested against three different influenza viruses (A/California/07/2009 (H1N1pdm09), A/Texas/50/2012 (H3N2), and B/Massachusetts/2/2012) for hemagglutination inhibition titer and virus neutralization titer via a microneutralization (MN) assay, and data compared to that obtained for standard serum sample collected in SST. HAI and MN titers against type A viruses were within two dilutions compared to SST collection method over 96% of the time irrespective of sample type or anticoagulant. However, HAI titers for type B virus were more variable across different collection methods. EDTA plasma samples were greater than two dilutions higher than SST serum samples 70% (21 of 30 samples) of the time. In contrast, MN titers were within two dilutions over 96% of the time, with the highest deviation noted in acid citrate dextrose plasma samples (3 of 30 samples tested, 10%). These data provide useful guidelines for sample collection and serology testing when screening: (i) influenza vaccine immunogenicity antibody response; (ii) antibody responses to newly emerging viral strains; and (iii) clinical samples for anti-influenza antibody activity.
Hemagglutination assay
Serial dilution
Cite
Citations (10)
Bovine serum albumin
Cite
Citations (2)
Rubella virus
Hemagglutination assay
Cite
Citations (0)
Hemagglutination (HA) and hemagglutination inhibition (HI) tests for avian influenza (AI) virus (H5N1) were standardized varying various factors like erythrocytes from different species, type of diluent, incubation temperature and incubation period. The virus was propagated in embryonated chicken eggs (9-11 days). The allantoic fluid (AF) was harvested 36 hours post incubation and was confirmed by spot agglutination test and agar gel precipitation test. The maximum HA titres were obtained using 1% RBCs of chicken, human blood (O) and dog at 22-37 C for 30-40 minutes. The AI virus subtype H5N1 eluted rapidly with higher temperature and maximum elution was observed within 8 hours. The maximum HI titres were obtained using 4 HA units of AI virus antigen compared to 1 or 8 HA units.
Embryonated
Incubation period
Hemagglutination assay
Agglutination (biology)
Cite
Citations (2)
Highly active test sera detecting the presence of virus antigen both in concentrated and purified preparations and in allantoic virus cultures directly adsorbed on the solid phase have been proposed for successful identification and detection of influenza A and B virus variants. After direct sorption of purified and concentrated virus preparations, the test sera to influenza A (H1N1, H2N2, H3N2) virus detect the virus antigen in a concentration of 8 ng/ml, test sera to influenza B virus in a concentration of 40 ng/ml. After sorption on the solid phase of allantoic virus cultures the test sera detected influenza A virus antigen in a dose of 0.25-1 agglutinating units (AU), and antigen of influenza B virus in a dose of 1-2 AU.
Cite
Citations (1)
Objective: The Vero cell-adapted Influenza Virus strain A/Yunnan/1/2005Va(H3N2) was a high-yield virus strain on Vero cell which can be applied to the production of Vero cell-based inactivated split influenza vaccine.By successive passage at low temperature,a Vero cell based cold-adapted influenza virus strain can be produced which can be used as a vaccine candidate strain for live attenuated cold-adapted influenza virus vaccine.The aim of this study was to establish a ELISA method for detection of a Vero cell-adapted Influenza Virus strain A/Yunnan/1/2005Va(H3N2) so as to do further research on Vero cell based cold-adapted influenza virus strain.Methods: Goats and chickens were immunized with the purified strain.And then antiserum was purified by methods of ammonium sulfate precipitation and Protein G affinity chromatography.Goat anti-A/Yunnan/1/2005Va(H3N2) IgG was coated on the ELISA plate and chicken anti-A/Yunnan/1/2005Va(H3N2) IgG was the second antibody.The optimal concentration of the two kinds of antibodies and enzyme-labeled antibody were determined in this study.Results: The optimal concentration of two kinds of antibodies were 5 μg/mL(goat) and 10 μg/mL(chicken) respectively,and the optimal dilution ratio of the enzyme-labeled antibody was 1:4000.The sensitivity of the ELISA was higher than that of hemagglutination assay.Conclusion: A ELISA method for detection of a Vero cell-adapted influenza virus strain A/Yunnan/1/2005Va(H3N2) was initially established in this study by determining the optimal concentration of the two kinds of antibodies and enzyme-labeled antibody.The ELISA method,which was simple,convenient,quick and sensitive,was applied to detection of a Vero cell-adapted influenza virus strain in the process of the development of a Vero cell based cold-adapted influenza virus strain.Thus,the ELISA method was of profound significance for the research on live attenuated cold-adapted influenza virus vaccine.
Vero cell
Strain (injury)
Hemagglutination assay
Cite
Citations (0)
Difficulties were often encountered in carrying out hemagglutination inhibition test with Asian influenza virus, for there were non-specific inhibitors against Asian influenza virus in sera of many animals. In addition, the properties of the inhibitor appeared somewhat different from those of inhibitors so far described.Following experiments were made in order to elucidate the nature of the inhibitor and to estimate its content in sera from various animals.1) Hemagglutination inhibition titers of egg white and normal sera from nine species of animals against various strains of influenza virus were determined. Changes in their inhibition titers, after various treatments were also examined. A/Adachi/2/57, now used as a standard strain of Asian influenza virus in Japan, was readily inhibited by many of normal animal sera, especially in high titer by horse, swine and guinea pig sera.2) The inhibitory activity was heat stable, destroyed neither by RDE (crude filtrate of the culture of V. cholerae) treatment nor by trypsin treatment, but was readily destroyed by KIO4 treatment. Marked difference in its inhibition titer against live virus and indicator virus of A/Adachi/2/57 was not observed. A/Adachi/2/57 was neutralized by normal horse serum in embryonated eggs. The neutralizing activity was also inactivated by KIO4 treatment. Based upon these results, the inhibitor against A/Adachi/2/57 is considered to be distinct from α and β inhibitors, and the term γ inhibitor was proposed. Comparison of properties of α, β and γ inhibitors and their contents in sera of various animals were diagramatically shown.3) A correlation was found between hemagglutination inhibition by human antisera and that by inhibitor, at least with six strains of Asian influenza virus so far examined. A/Kumamoto/Y5/57, which was not inhibited by γ inhibitor in hemagglutination, was not also neutralized by γ inhibitor in embryonated eggs.4) Addition of two volumes of M/100 KIO4 to one volume of sample was recommended as a useful procedure in practice in order to remove γ inhibitor in hemagglutination inhibition test. This treatment did not seriously affect specific antibody titer.
Embryonated
Hemagglutination assay
Cite
Citations (2)
High sensitivity and specificity of solid-phase radioimmunoassay (SPRIA) in identification of influenza A (H1N1 and H2N2) viruses in the infected allantoic culture were demonstrated. Mixtures of influenza hyperimmune sera free from antibodies to host cell antigens and antineuraminidase antibodies were used as active test sera. The test serum a-H1N1 consisted of antisera to A/FmI/47, A/Netherlands/36/56, and A/USSR/090/77 strains; it detected practically all tested variants of H1N1 virus isolated in 1947-1982 in allantoic cultures containing virus-specific protein in amounts of 1.4 to 0.7 ng/ml. For the detection of H2N2 subtype viruses (1957-1967), a mixture of antisera to A/Singapore/1/57, A/Leningrad/2/63, A/Gorkiy/62/65, and A/Tokyo/3/67 viruses was used. This test serum could detect H2N2 virus in the allantoic fluid containing 0.7-035 ng/ml of virus protein.
Cite
Citations (0)