Kinetic studies on the sialidase of three influenza B and three influenza A virus strains

1989 ◽  
Vol 6 (2) ◽  
pp. 219-227 ◽  
Author(s):  
Jos� A Cabezas ◽  
Milagros Milicua ◽  
Carmen S Bernal ◽  
Enrique Villar ◽  
Nieves Perez ◽  
...  
1944 ◽  
Vol 79 (6) ◽  
pp. 633-647 ◽  
Author(s):  
William F. Friedewald

A study of the PR8, Christie, Talmey, W.S., and swine strains of influenza A virus by means of antibody absorption tests revealed the following findings: 1. Serum antibody could be specifically absorbed with allantoic fluid containing influenza virus or, more effectively, with concentrated suspensions of virus obtained from allantoic fluid by high-speed centrifugation or by the red cell adsorption and elution technique. Normal allantoic fluid, or the centrifugalized sediment therefrom, failed to absorb antibodies. Influenza B virus (Lee) caused no detectable absorption of antibody from antisera directed against influenza A virus strains, but it specifically absorbed antibody from Lee antisera. 2. The neutralizing, agglutination-inhibiting, and complement-fixing anti-bodies in ferret antisera were completely absorbed only by the homologous virus strain, even though 2 absorptions were carried out with large amounts of heterologous virus strains. 3. PR8 virus appeared to have the broadest range of specific antigenic components for it completely absorbed the heterologous antibodies in Christie and W.S. antisera and left only those antibodies which reacted with the respective homologous strains. The other virus strains (Christie, Talmey, W.S., swine) were more specific in the absorption of heterologous antibodies and completely removed only those antibodies which reacted with the absorbing virus. 4. The absorption tests revealed a higher degree of specificity and individuality of the virus strains than the various cross reactions previously reported. The strain specificity of PR8 virus was equally manifest in absorption tests with ferret sera and with human sera following vaccination. 5. The amount of homologous antibody remaining in a PR8 ferret serum after absorption with PR8 virus, obtained by the red cell adsorption and elution method, varied inversely as the concentration of virus used for absorption. A given concentration of virus, however, absorbed a greater percentage of neutralizing antibodies than either agglutination-inhibiting or complement-fixing antibodies.


BIOPHYSICS ◽  
2020 ◽  
Vol 65 (2) ◽  
pp. 222-224
Author(s):  
G. S. Onkhonova ◽  
P. Yu. Torzhkova ◽  
V. Yu. Marchenko ◽  
S. V. Svyatchenko ◽  
A. S. Gudymo ◽  
...  

Folia Medica ◽  
2015 ◽  
Vol 57 (2) ◽  
pp. 104-110 ◽  
Author(s):  
Golubinka Bosevska ◽  
Nikola Panovski ◽  
Elizabeta Janceska ◽  
Vladimir Mikik ◽  
Irena Kondova Topuzovska ◽  
...  

AbstractEarly diagnosis and treatment of patients with influenza is the reason why physicians need rapid high-sensitivity influenza diagnostic tests that require no complex lab equipment and can be performed and interpreted within 15 min. The Aim of this study was to compare the rapid Directigen Flu A+B test with real time PCR for detection of influenza viruses in the Republic of Macedonia. MATERIALS AND METHODS: One-hundred-eight respiratory samples (combined nose and throat swabs) were routinely collected for detection of influenza virus during influenza seasons. Forty-one patients were pediatric cases and 59 were adult. Their mean age was 23 years. The patients were allocated into 6 age groups: 0 - 4 yrs, 5 - 9 yrs, 10 - 14 yrs, 15 - 19 yrs, 20-64 yrs and > 65 yrs. Each sample was tested with Directigen Flu A+B and CDC real time PCR kit for detection and typisation/subtypisation of influenza according to the lab diagnostic protocol. RESULTS: Directigen Flu A+B identified influenza A virus in 20 (18.5%) samples and influenza B virus in two 2 (1.9%) samples. The high specificity (100%) and PPV of Directigen Flu A+B we found in our study shows that the positive results do not need to be confirmed. The overall sensitivity of Directigen Flu A+B is 35.1% for influenza A virus and 33.0% for influenza B virus. The sensitivity for influenza A is higher among children hospitalized (45.0%) and outpatients (40.0%) versus adults. CONCLUSION: Directigen Flu A+B has relatively low sensitivity for detection of influenza viruses in combined nose and throat swabs. Negative results must be confirmed.


1998 ◽  
Vol 143 (4) ◽  
pp. 653-666 ◽  
Author(s):  
L. Englund ◽  
C. Hård af Segerstad

2009 ◽  
Vol 387 (2) ◽  
pp. 405-408 ◽  
Author(s):  
Yonghui Zhang ◽  
Xiaojing Lin ◽  
Fengwei Zhang ◽  
Jia Wu ◽  
Wenjie Tan ◽  
...  

1988 ◽  
Vol 11 ◽  
pp. 88
Author(s):  
Otto Haller ◽  
Peter Juelke ◽  
Jerome L. Schulman

2018 ◽  
Vol 6 (12) ◽  
Author(s):  
Manabu Nemoto ◽  
Takashi Yamanaka ◽  
Hiroshi Bannai ◽  
Koji Tsujimura ◽  
Hiroshi Kokado

ABSTRACT We sequenced the eight segments of influenza A virus strains A/equine/Ibaraki/1/2007 and A/equine/Yokohama/aq13/2010, which are strains of the Florida sublineage clades 1 and 2 of the H3N8 subtype equine influenza virus. These strains have been used as vaccine strains in Japan since 2016 in accordance with World Organization for Animal Health (OIE) recommendations.


1947 ◽  
Vol 86 (5) ◽  
pp. 357-366 ◽  
Author(s):  
George K. Hirst

1. When strains of influenza A virus which have been isolated in chick embryos are introduced into the mouse lung, the virus multiplies readily and achieves initially a titer which is as high as is even obtained, even after repeated passage. The high initial titer of virus may be unaccompanied by any lethal or visible pathogenic effects; but with four or five mouse passages the agent becomes lethal in high titer and causes extensive pulmonary consolidation, though its capacity to multiply in the lung has not increased. In one example the adaptation to mouse lung was accompanied by increasing capacity to agglutinate guinea pig red cells without a corresponding increase in agglutinating power for chicken cells. Influenza B virus, in preliminary tests, did not behave in a similar fashion. 2. The adaptation of influenza A virus to mice is accompanied by changes in antigenic pattern, as detected by cross-tests with the agglutination inhibition method. Two strains, initially similar, with passage, changed in pattern along divergent paths so that they became not only unlike the parent strains but unlike each other. This finding has important implications for the interpretation of the strain difference problem in human influenza.


2012 ◽  
Vol 86 (20) ◽  
pp. 11183-11193 ◽  
Author(s):  
P. Osterlund ◽  
M. Strengell ◽  
L. P. Sarin ◽  
M. M. Poranen ◽  
R. Fagerlund ◽  
...  

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