1,720,983 research outputs found
Chromomycin A3 inhibits influenza a virus multiplication in chick embryo fibroblast cells
No full textAbstract
The multiplication of Ulster 73 virus, an avian strain of type A influenza virus, was blocked in chick embryo fibroblast cells, CEF, by treatment with 0.5 microg/ml of chromomycin A3 whereas in LLC-MK2 cells no inhibition of replication was observed. Virus-induced polypeptide synthesis in chick embryo fibroblast cells was confined to the synthesis of PB2, PB1 and PA subunits of the RNA dependent-RNA polymerase, the nucleoprotein NP, the non-structural protein NS1, the haemagglutinin HA, the non-structural protein NS2; only the membrane M1 polypeptide synthesis was greatly inhibited. Viral unpolyadenylated cRNAs synthesis was studied at a late time of the infection, 8 hours p.i.: chromomycin A3 was able to inhibit the "novo" synthesis of complementary RNA poly(A)- and segment 7 of virion RNA. The mode of action of the drug in chick embryo fibroblast cells is discussed.
PMID: 12437217 [PubMed - indexed for MEDLINE
Inhibitory effect of diamidinophenylindole on the replication of influena virus in permissive cellular host.
No full textAbstract
The production of avian and human strains of influenza virus was altered to various extents by treatment of various host cells with 40 micrograms/ml of diamidinophenylindole (DAPI). In infected LLC-MK 2 cells only an abortive replication cycle occurred; in other cell lines there was partial inhibition or no inhibition of replication. Virus polypeptide synthesis in LLC-MK 2 cells was confined to the early pattern of viral multiplication; only the P proteins, the nucleoprotein NP, and the non-structural protein NS 1 were synthesized. The stage of replication mainly affected by DAPI was between the fourth and the sixth hour after infection. The mode of action of the drug and its modulating effect on virus production is discussed.
PMID: 3579606 [PubMed - indexed for MEDLINE
Defective insertion of haemagglutinin as a cause of abortivity of influenza A viruses in HeLa 229 cells.
No full textAbstract
A number of experimental data demonstrate that certain mammalian cells are unable to replicate Influenza viruses type A. In these cellular hosts the viruses can efficiently perform their biological as well as biochemical activities but the production of mature viral particles is greatly restricted. Here we report a study of abortiveness of human and avian type A Influenza viruses in HeLa 229 cells in which the final stages of maturation of viral particles seem to be affected. We show that the incorrect insertion of virus-coded haemagglutinin into the plasma membrane might be the cause of the unpermissive condition of infection exhibited by this cellular host.
PMID: 1775092 [PubMed - indexed for MEDLINE
Radio immune Western blotting: a possible solution to indeterminate conventional Western blotting results for the serodiagnosis of HIV infections.
No full textAbstract
Western blot is used worldwide as a confirmatory assay after a positive or doubtful ELISA result in the serodiagnosis of HIV infections. Despite the use of this test some results may be not definitive due to the presence in Western blot of only few or a single band to HIV protein. This result has been defined as indeterminate. To resolve indeterminate results obtained with conventional Western blotting (WB) we used radio immune Western blotting (RIWB), a method capable of detecting antibodies to HIV-1 proteins with greatly increased sensitivity with respect to conventional WB. We used RIWB to perform a retrospective survey on 20 sera belonging to individuals undergoing HIV serodiagnosis (not blood donors) with positive or borderline EIA results, and indeterminate WB results who only later fully seroconverted. Fifteen of the sera tested by RIWB showed a positive result which clarified any doubtful indeterminate WB result; all bands present in conventional WB were enhanced in intensity using RIWB and new bands, absent in the WB assay, were highlighted using RIWB. RIWB may resolve most indeterminate WB results.
PMID: 8673856 [PubMed - indexed for MEDLINE
Inhibition of human and avian type A Influenza virus multiplication performed by MESNA
No full textThe antiviral activity of MESNA, a thiol group compound, was evaluated in LLC-MK2 cells infected by Influenza virus.
MESNA was able to inhibit viral multiplicaton in a dose-dependent fashion and virus yield, obtained both with HA and plaque assaies, was reduced at concentrations which did not suppress protein synthesis in mock-infected cells.
MESNA treatment determined a marked reduction of the normal synthesis of early and late virus-induced proteins suggesting an action on viral transcriptase.
However, “in vitro” assay of viral RNA dependent-RNA polymerase activity performed on purified virions showed negative results in that MESNA was not able to inhibit or block virus enzyme activity.
This evidence led us to hypothesise a possible involvement of a cellular factor (s). We have investigated the role and the concentration of the ratio Ox-Red glutathione, GSSG / GSH.
Results obtained demonstrate a correlation between the intracellular concentration of GSH and progression/ inhibition of viral infection.
In particular, the results reported here demonstrate that the amounts of GSH reached into the cells are a direct consequence of MESNA treatments.
Data obtained with human influenza virus strain, A, NWS, H1N1, were completely reproducible and comparable with those obtained with avian influenza virus strain, A, Ulster 73, H7N1.
Furthermore, data obtained in MDCK cells were comparable to those, above described, obtained in LLC-MK2 cells.
Corresponding Author: prof. Giorgio Cont
ROLE OF ACYLATION OF VIRAL HAEMAGGLUTININ DURING THE INFLUNZA VIRUS INFECTIOUS CYCLE
No full textAbstract
We investigated fatty acid residues bound to the haemagglutinin (HA) of type A influenza viruses by growing the viruses in permissive chick embryo fibroblasts (CEF) and in non-permissive HeLa-229 cells using a maintenance medium containing 3H-palmitic acid. Our results suggest that fatty acid acylation of the major viral glycoprotein may be an important prerequisite for the production of mature viral particles. Indeed, palmitoylation is found in infected CEF, but is completely lacking in non-permissive HeLa-229 cells infected by the same virus strains. We conclude that this type of post-translational modification of virus HA glycoprotein could be a general phenomenon regulating the maturation and budding of influenza virus.
PMID: 1297175 [PubMed - indexed for MEDLINE
Improved immunoblotting for the detection and quantitative analysis of antibodies to human immunodeficiency virus.
No full textAbstract
Detection of antibodies to single HIV-1 proteins was performed by modified Western-blotting procedure. The use of [35S]-Streptavidin instead of Avidin-peroxidase conjugate greatly enhances the sensitivity of the method and enables useful quantitative analysis of results.
PMID: 1783068 [PubMed - indexed for MEDLINE
The use of radioimmune western blotting to evaluate indeterminate western blotting results in blood donor HIV serodiagnosis
No full textAbstract
The serodiagnosis of HIV infection is sometimes puzzling due to questionable "indeterminate" results obtained by western blotting (wb), the confirmatory test used world-wide after a positive or borderline ELISA result. These situations cause anxiety in the person being tested and determine additional laboratory costs. We showed that radioimmune western blottting (riwb) an improved and sensitive modification of conventional wb, was able to resolve most "indeterminate" results in individuals who later fully seroconverted. We report in this paper the use of riwb in sera of 20 uninfected blood donors with an indeterminate wb continuing for at least 6 years, to verify the serological status in indeterminate not at risk individuals. Thirteen out of the 20 were indeterminate with conventional wb due to the presence of antibodies to p 24, two to p 17, two to p 55, two to p 51 and p 55 and one to p 24 and p 51 antibodies. The presence of all these bands was confirmed using riwb; moreover, in comparison with wb, the intensity of all bands was clearly enhanced. Despite the use of this highly sensitive method no new bands were found with riwb in indeterminate sera; negative results were obtained when sera borderline or positive with ELISA but negative with wb, were subjected to riwb.
PMID: 9258947 [PubMed - indexed for MEDLINE
THE USE OF SODIUM 2-MERCAPTOETHANESULFONATE AS ANTIVIRAL AGENT Description not available for EP1596851 (A1) Description of corresponding document: WO2004069235 (A1)
No full textClassification:
- international: A61K31/185; A61P11/00; A61P31/12; A61P31/16; A61K31/185; A61P11/00; A61P31/00; (IPC1-7): A61K31/185; A61P11/00; A61P31/12; A61P31/16
- European: A61K31/185
Application number: EP20040706141 20040129
Priority number(s): WO2004EP00779 20040129; IT2003MI00175 2003020
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