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  • 1
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary.  Mutations in the fusion, F, protein of Sendai virus resulting in increased cleavability by ubiquitous host protease(s), and mutations in the matrix, M, protein resulting in bipolar budding, are both important determinants for the systemic infection in mice caused by the protease activating pantropic mutant, F1-R. Several mutants of Sendai virus (BY, BF, and KD-M) with phenotypes of bipolar budding and/or increased cleavability of F protein were isolated. Genomic RNA sequence analysis of the F and M genes of the mutants revealed that several deduced amino acids in the F and M proteins were different from those of F1-R, T-5 (a revertant of F1-R), and wild-type viruses. The BF and KD-M mutants that budded bipolarly and were also activated by ubiquitous proteases were examined for replication in tissue culture cells and in mice. All of the mutants exhibited multiple-step replication in MDCK, MDBK, and LLC-MK2 cells without trypsin, but formed plaques only in MDCK cells. One of the mutants, designated KD-52M, was similar to F1-R in that it formed plaques in all three cell lines without addition of exogenous protease. However, none of the mutant viruses, including KD-52M, caused a systemic infection in mice. The mutated M protein of F1-R enhances the disruption of microtubles. However, none of the mutants with a bipolar budding phenotype (BY, BF, and KD-M), disrupted the microtubules to the same extent as F1-R. All of these mutants had mutations in the M protein that were different from those found in F1-R. Taken together, these results suggest that mutations at Ser115 to Pro in the F protein and at Asp 128 to Gly and Ile210 to Thr in the M protein of F1-R are the mutations specifically required for the systemic infection caused by F1-R.
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  • 2
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Chorioallantoic membrane (CAM) tissue cultures were found to be permissive for representative paramyxoviruses. The CAM cells can be used for plaque assay without the presence of trypsin. Ultrastructures of CAM cells infected with paramyxovirus Yucaipa (PMY), Sendai virus, and NDV were different. Nucleocapsids were readily seen in budding structures of cells infected with PMY, and in Sendai virus infected cells, large clusters of nucleocapsids were clearly evident in the cytoplasm. The site of glycoprotein cleavage does not have any effect on the nature of budding. It appears that a factor or factors in addition to the nature of the plasma membrane influences the morphology of cells infected with paramyxoviruses.
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  • 3
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Persistent infections (Pi) were established in two host-cell systems [Madin-Darby bovine kidney (MDBK) and Madin-Darby canine kidney (MDCK)] with Sendai virus and three strains of NDV, to test the influence of different viruses and host-cell systems. Virus was recovered from the persistently infected cells. An RNA- ts mutant was recovered from a Pi of MDBK cells, but no Pi could be established in MDCK cells with the three strains of NDV. Additionally, the Pi was established exclusively by a virulent strain, NDV-Milano. On the other hand, Sendai virus could establish Pi in MDBK and MDCK cell-systems. Several ts mutants were recovered from “late” passages of Pi, and from an accidental infection, a ts mutant with an altered P polypeptide. Ten other ts mutants were tested, however, the specific ts lesion could not be identified. From three Pi in MDCK cells, host range mutants (ts-f1, ts-f2, and ts-f3) were recovered. One of the mutants (ts-f1) has an altered M (matrix) protein. The host range mutants undergo a productive infection in MDBK and MDCK cells, which are nonpermissive for wild type Sendai virus. The possible significance of the results are discussed.
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  • 4
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cultured cells of the chorioallantoic membrane (CAM) fulfilled the need of using the same cell system that was permissive for representative paramyxoviruses to carry out studies on the biosynthesis of their glycoproteins in infected cells. The polypeptide composition of the respective paramyxoviruses [Newcastle disease virus (NDV), paramyxovirus Yucapipa (PMY), and Sendai virus], grown in eggs and CAM-cells, was essentially identical. In egg-grown PMY a large glycoprotein (LGP) was present but only in some CAM-grown preparations of virus labeled with [3H]-glucosamine and rarely in [35S]-methionine or [3H]-amino acids (valine, leucine, and tyrosine) labeled viruses. The site of cleavage of precursor F0 to F1,2 was not the same. In contrast to the cleavage of Sendai virus glycoprotein, cleavage was intracellular in NDV and PMY infected cells. Homologous antisera against the glycoproteins failed to inhibit cleavage of HN0 or F0 in cells infected with the representative paramyxoviruses.
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  • 5
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The protective effects of the passive administration of convalescent serum from mice infected with Sendai virus were evaluated in mice challenged intranasally with wild-type and a pantropic variant (F1-R) of Sendai virus. Adoptive transfer of the serum efficiently prevented F1-R from infecting the systemic organs, but it failed to protect the mice from infections of the respiratory tracts by either virus. Virus replication in nasal turbinates was not diminished while infection in the lung was suppressed sufficiently for the infected mice to survive the infection. These findings suggest that serum antibody is less effective for the protection against viral infections on the surface of the respiratory tract, but it is effective for inhibition of spread of the virus into the systemic organs.
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  • 6
    ISSN: 1432-8798
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fusion (fusion from within) of polarized MDCK monolayer cells grown on porous membranes was examined after infection with Sendai viruses. Wild-type virus, that buds at the apical membrane domain, did not induce cell fusion even when the F glycoprotein expressed at the apical domain was activated with trypsin. On the other hand, a protease activation mutant, F 1-R, with F protein in the activated form and that buds bipolarly at the apical and basolateral domains, caused syncytia formation in the absence of exogenous protease. Anti-Sendai virus antibodies added to the basolateral side, but not at the apical side, inhibited cell fusion induced by F 1-R. In addition, T-9, a mutant with bipolar budding phenotype of F 1-R but with an uncleavable F protein phenotype like wild-type virus, induced cell fusion exclusively when trypsin was added to the basolateral medium. By electron microscopy, cell-to-cell fusion was shown to occur at the lateral domain of the plasma membrane. These results indicate that in addition to proteolytic activation of the F protein, basolateral expression of Sendai virus envelope glycoproteins is required to induce cell fusion.
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  • 7
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 213 (1967), S. 188-189 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] For this purpose "purified" enzyme was prepared from Japan 305 virus and used for the immunization of rabbits for the production of anti-sialidase antiserum by methods previously reported3'4. Virus preparations were prepared, assayed for haemagglutinins and egg infectivity as described ...
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  • 8
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Résumé La production de la protéine en phase aiguë chez le lapin (CxRP), après injection stimulante de thérébenthine, a été arrêtée par l'application i.p. d'actinomycine D. Cette inhibition durait environ 12 h.
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  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Notes: Disc electrophoresis per se and in combination with immunodiffusion procedures facilitated the characterization of sialidase. Irrespective of the isolation procedures, sialidase of influenza virus (A2 Japan 305/57) appeared to be electrophoretically heterogeneous. This was indicated by disc electrophoresis and analysis of eluates in the “segmentation experiments” and by the “disc immunodiffusion” techniques. It was further noted that “purified” sialidase in phosphate buffer stored at 0 to 5°C. dissociated and simultaneously lost 90 per cent of its enzyme activity. The procedures described above proved valuable, particularly when analyzing limited quantities of material.
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  • 10
    ISSN: 1432-1831
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In evaluating action of chemicals and proteolytic enzymes on Newcastle disease viruses for solubilizing their surface antigens, nonionic detergents (Tween 20, Triton X-100, Nonidet P-40, and Sterox SL) were shown to be the most effective. Solubilized antigen preparations, in particular of alkali-Tween 20 treated material, were purified by a simple procedure in a DEAE-cellulose column equilibrated with pH 10 bicarbonate buffer containing 1% Tween 20 and eluted with the same buffer supplemented with 0.5 M-NaCl. Such preparations had sialidase, antibody blocking and/or haemagglutinating activities. The enzyme-haemagglutinin (E-HA) preparations of NDV-Beaudette with enzyme and haemagglutinating activities and NDV-Italien with enzyme and antibody blocking activities were shown, by polyacrylamide gel electrophoresis, to contain one and two glycoproteins, respectively. This apparent difference in the E-HA preparations of the two strains is consistent with their contrasting behaviour to action of chemicals and reflect differences in the envelope structure of the strains of NDV. The finding that NDV-Beaudette enzyme and haemagglutinin may have a common glycoprotein confirms the recent report by Scheid and Choppin (1973). Preliminary results suggest that sialidase of NDV is antigenically unrelated to the enzyme of Sendai and Yucaipa
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