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the dynamics of development of cell resistance to viruses induced by synthetic polynucleotides.the dynamics of interaction of complexes of synthetic polynucleotides (polyinosinic and polycitidylic acid--poly (ri)-poly (rc), and polyguanylic and polycytidylic acid--poly (rg)-poly (rc)) with cells as well as the dynamics of interferon accumulation and development of antiviral effect against some rna viruses were studied in primary chick embryo cell (cec) cultures. four phases were observed in the development of the antiviral effect of synthetic polynucleotides: adsorption, increase, marked ...19767937
the production of chinese hamster interferon. 197611678
reversible inhibition of interferon-induced antiviral state by deoxyadenosine.deoxyadenosine reversibly inhibited the development of antiviral state (avs) in chick embryo fibroblasts stimulated by interferon. studies on cellular macromolecular syntheses in deoxyadenosine-treated cells suggested that the inhibition was related to nucleolar rna synthesis. reference experiments with actinomycin d and cordycepin (3'deoxyadenosine) also implied causal- or interrelation between avs development and nucleolar rna synthesis.197613641
antigenic characterization of two sindbis envelope glycoproteins separated by isoelectric focusing. 197654983
mutants of sindbis virus. i. isolation and partial characterization of 89 new temperature-sensitive mutants. 197662444
the spectrum of virus resistance of a kb cell strain resistant to diphtheria toxin. 1976176795
[identification of a hemadsorbing agent discovered in uninfected mouse l cell cultures and also the same cultures chronically infected with sindbis virus].electron microscope examinations of continuous lines of mouse l cells, both uninfected (l-init) and chronically infected with sindbis virus (l-sv) revealed accumulations of ribonucleoprotein strands and virions corresponding by their parameters to paramyxoviruses in the cytoplasms of the cells. further studies showed l-init and l-sv cell lines to have a manifest hemadsorption effect which could be completely inhibited by antiserum to parainfluenza sv5 virus. immunofluorescence procedures detecte ...1976176821
the effect of tilorone hydrochloride on the growth of several animal viruses in tissue cultures.tilorone hydrochloride, at a concentration of 10 mug/ml inhibits the growth of herpes simplex virus type 1 in bs-c-1 cells. the growth of vaccinia virus in bs-c-1 cells is partially inhibited; however, six viruses containing rna, including four members of the togavirus group grown in chick fibroblasts, are not affected by the drug. the inhibition of the growth of herpes virus by tilorone hydrochloride is greater when the multiplicity of infection is lower than 1 p.f.u/cell and when the drug is a ...1976177724
the susceptibility of isolated guts from various species of mosquito to some arboviruses.isolated guts cultured in vitro from aedes aeaegypti and ae. togoi were more susceptible to infection by sin, sf, chik and wn viruses than tissue similarly cultured from anopheles gambiae and an. stephensi. langat tp 64, a tick-borne virus, failed to infect any of the cultured mosquito tissues.1976178280
mapping of poly(a) sequences in the electron microscope reveals unusual structure of type c oncornavirus rna molecules.we have synthesized a convenient electron microscope label for mapping poly(a) sequences. short lengths of poly(dt) are polymerized onto nicked circular sv40 dna with the enzyme terminal deoxynucleotidyl transferase. an rna or dna molecule of interest is treated with glyoxal, hybridized briefly with the poly(dt) circles, and spread for microscopy; poly(a) stretches are clearly marked because they are attached to the poly(dt) on the easily recognized sv40 duplex circles. the rnas of several type ...1976182376
[stick-plaque test--an economic method of quantitative determination of viruses].an economic method for quantitative assay of viruses is presented. in this "canule stick-plaque test" (german abbreviation spt) samples of viruses, geometrically diluted and taken up by a canule, are inoculated by sticking into monolayer cell cultures overlayed with agar medium. a plaquelike cpe detectable by neutral red staining develops in the area of the inoculation. the frequency of this cpe formation depends on the concentration of viruses in the inoculated dilution. this dose-response allo ...1976186533
homologous interference induced by a temperature-sensitive mutant derived from an hvj (sendai virus) carrier culture.homologous interference between a temperature-sensitive small plaque mutant (hvj-pb) derived from an hvj (haemagglutinating virus of japan - the sendai strain of parainfluenza i virus) carrier culture of bhk cells and the original wild-type virus (hvj-w) has been investigated. prior infection of llcmk2, hela, bhk or mouse l cells with hvj-pb, both at permissive and non-permissive temperatures, for 24 h resulted in a reduced yield of superinfecting hvj-w, reflecting a smaller number of cells capa ...1976186564
production of interferon in human diploid cell cultures.eleven human diploid cell lines were compared for their ability to produce interferon in response to newcastle disease virus. sensitivity of the cultures of mm, sindbis vsv and vr viruses was also studied. human cells derived from various tissue of a single embryo responded variably to interferon inducer. using selected viruses interferon production was studied in two systems, in cultures of leukocytes and in human embryonic cells.1976187142
enhanced resistance of mice to infection with langat (tp21) virus following pre-treatment with sindbis or semliki forest virus.significant protection to heterologous i.c. challenge with the flavovirus langat occurred after a single i.c. injection of avirulent strains of the alpha viruses semliki forest or sindbis given 1 day to 5 weeks before challenge. some protection also occurred after an i.p. infection with these viruses. we consider that the protection afforded by the alpha viruses is due to interference with the multiplication of langat virus and is related to the maximum level of brain infectivity reached in the ...1976187719
[stich-plaque test--an economic method for quantitative determination of viruses].an economic method for quantitative assay of viruses is presented. in this "canule stick-plaque test" (german abbreviation spt) samples of viruses, geometrically diluted and taken up by a canule, are inoculated by sticking into monolayer cell cultures overlayed with agar medium. a plaquelike cpe detectable by neutral red staining develops in the area of the inoculation. the frequency of this cpe formation depends on the concentration of viruses in the inoculated dilution. this dose-response allo ...1976188946
study on the mechanism of interference between friend leukemia and sindbis viruses in tissue culture.some mechanisms of interference developing in balb/c mouse embryo fibroblast culture (mec) infected with friend leukemia virus (flv) and 48 hours later superinfected with sindbis virus (sv) was studied. in flv-infected cells the amount of sv antigen formed was 2-3 times lower than in sv monoinfection, as indicated by immunofluorescence and cytofluorimetry. electron microscopic examination showed that in mixed infection the number of newly formed sv particles decreased markedly (by 90%) despite t ...1976775350
[clinical and epidemiologic significance of arboviruses in central europe]. 1976794666
[a rapid assay of sindbis virus infectivity by counting immunofluorescence foci in "aedes albopictus" cell culture (author's transl)].the aedes albopictus cell line is susceptible to numerous arboviruses but the appearance of cytopathic effect is observed mostly with flavivirus. a method of rapid titration of sindbis virus by counting immunofluorescent foci is described, using this cell line.1976799476
immediate glycosylation of sindbis virus membrane proteins.the mechanism by which the membrane proteins of sindbis virus are initially glycosylated during growth of the virus in chick cells was studied. the experiments suggest strongly that the two viral glycoproteins are glycosylated before release from the polysome, and that this glycosylation involves transfer of a large 1800 dalton oligosaccharide to the polypeptide chains. the donor of the oligosaccharide is most probably a lipid.1977558830
synthesis of sindbis virus nonstructural polypeptides in chicken embryo fibroblasts.the identification of eight previously undescribed polypeptides in chicken embryo cells infected with sindbis virus is reported. seven of these polypeptides were distinguishable from the virus structural polypeptides and their precursors by their molecular weights and tryptic peptide maps. the eighth was closely related to pe2 (schlesinger and schlesinger, 1973), a precursor to one of the virus particle glycoproteins. pulse-chase experiments and the use of an inhibitor of proteolytic cleavage al ...1977559103
virus-directed post-translational cleavage in sindbus virus-infected cells.the viral polypeptides synthesized in cells coinfected with group c and group d or e sindbis virus mutants were studied. cleavage of the ts2 protein occurs in cells coinfected with ts2 and ts20. since the ts2 protein fails to chase in cells infected with ts2 alone, the activity effecting this cleavage must be, at least in part, virus specified.1977559105
role of extracellular virus on the maintenance of the persistent infection induced in aedes albopictus (mosquito) cells by sindbis virus.sindbis virus infection of cultured mosquito cells was found to have no effect on the growth of these cells; instead, a persistent infection of the culture followed an initial acute phase of rapid virus synthesis. nearly all of the cells in the acute stage of infection were found to actively release virus in an infectious-center assay and to contain significant amounts of virus antigen as determined by immunofluorescence. cells in the persistent phase of infection released few virions into the m ...1977561193
tunicamycin inhibits glycosylation and multiplication of sindbis and vesicular stomatitis viruses.tunicamycin (tm), an antibiotic that inhibits the formation of n-acetylglucosamine-lipid intermediates, thereby preventing the glycosylation of newly synthesized glycoproteins, inhibits the growth of sindbis virus and vesicular stomatitis virus in bhk cells. at 0.5 mug of tm per ml, the replication of both viruses is inhibited 99.9%. noninfectious particles were not detected. all the viral proteins were synthesized in the presence of tm, but the glycoproteins were selectively altered in that the ...1977189071
the protease inhibitor p-nitrophenyl-p' -guanidinobenzoate inactivates sindbis and other enveloped viruses. 1977190790
sindbis virus messenger rna: the 5'-termini and methylated residues of 26 and 42 s rna. 1977193248
integration of genomes on infectious viruses.the article contains a review relating to the integration of genomes of infectious viruses in eukaryotic cells. data are presented that were obtained in the study of tissue cultures chronically infected with viruses, in the study of pathologic and ecologic processes. based on the evidence accumulated, some theoretical and applied aspects of the problem are discussed.1977194142
variables affecting viral plaque formation in microculture plaque assays using homologous antibody in a liquid overlay.a liquid antibody microculture plaque assay and the variables that govern its effectiveness are described. the assay is based on the principle that low concentrations of homologous antibody can inhibit secondary plaque formation without inhibiting formation of primary plaques. thus, clear plaques that followed a linear dose response were produced. the assay was found to be more rapid, less cumbersome, and less expensive than assays using agar overlays and larger tissue culture plates. it was rep ...1977194918
sindbis virus-induced cytopathic effect in clones of aedes albopictus (singh) cells. 1977196393
growth medium utilization and its re-use for animal cell cultures. 197714164
stability in drinking and surface water of nine virus species from different genera (author's transl).the stability of nine viruses, aujeszky, sindbis, vesicular stomatitis, newcastle disease, vaccinia, fmd, hcc, reo and teschen virus in drinking and surface water was investigated comparatively at temperatures of 9 and 15 degrees c as well as the influence of water factors like seasonal difference in temperature, ph value, hardness and sort of water. the results can be summarized as follows: 1. at temperatures of 9 to 15 degrees c the majority of the viruses remained stabil in natural water for ...197714460
glycosidase susceptibility: a probe for the distribution of glycoprotein oligosaccharides in sindbis virus.intact sindbis virus and triton-solubilized viral glycoprotein were treated with alpha-mannosidase and with a preparation of mixed glycosidases from diplococcus pneumoniae to probe the accesibility of carbohydrate units on the viral surface. the products of glycosidase attack on triton-solubilized virus showed that mose carbohydrate units of the glycoproteins are good substrates for these enzymes. the relative resistance of most of the viral oligosaccharides in intact virus particles showed that ...197718614
isolation of sindbis (alphavirus) and leanyer viruses from mosquitoes collected in the northern territory of australia, 1974.mosquitoes collected near darwin, northern territory, in 1974 yielded two virus strains. one was identified as sindbis virus, not previously isolated from the northern territory. the other is antigenically distinct from viruses previously isolated from arthropods in australia, and the name "leanyer" is proposed for it. its properties suggest that it may be a togavirus serologically unrelated to available alphaviruses and flaviviruses.197723749
[interaction of sindbis virus with a culture of cells producing oncornavirus].electron microscopy and biophysical methods were used for examinations of primarily trypsinized chick fibroblast cell culture spontaneously producing c-type oncornavirus at 1, 6, and 24 hours after inoculation with sindbis virus. during the first 6 hours rapid maturation and release of oncornavirus from cells were observed. at later intervals oncornavirus production was inhibited. it is assumed that in the system under study, biosynthesis of oncornavirus and sindbis virus occur separately.1977198967
adjuvant polyarthritis. iii. evidence in support of viral etiology.intraperitoneal administration of a relatively small volume (0.2 ml) of plasma obtained from sindbis virus--infected animals containing approximately 480 units of interferon/ml effectively suppressed the development of adjuvant arthritis. similarly, administration of interferon (624 units/rat/day, ip) prepared in vitro by exposing rat embryo fibroblast culture to poly i:c in the presence of cycloheximide also suppressed the development of adjuvant arthritis without affecting the humoral or the c ...1977200247
impaired intracellular migration and altered solubility of nonglycosylated glycoproteins of vesicular stomatitis virus and sindbis virus.tunicamycin, an antibiotic which prevents the glycosylation of newly synthesized proteins, inhibits the replication of both vesicular stomatitis virus and sindbis virus. in tunicamycin-treated infected cells, all of the viral proteins are synthesized but the glycoproteins are devoid of carbohydrate. the nonglycosylated glycoproteins could not be detected on the outside of the plasma membrane by lactoperoxidase labeling, indirect immunofluorescence staining, or chymotrypsin treatment of intact ce ...1977200626
[serum-treatment in the rubella hi-test by menas of silicic acid (author's transl)].the serum treatment for the removal of nonspecific inhibitors in the rubella hi-test with silicic acid was investigated by means of isolated lipoproteins and after a micromethod by means of sindbis-virus. reduction of the three classes of lipoproteins after treatment with silicic acid was good. in the sindbis hi-test only 2% of the sera showed low titers after treatment. the method proved to be a reliable tool as removal of unspecific inhibitory activity is concerned.1977201128
studies on the occurrence and distribution of hi antibodies against some arboviruses in the serum of domestic mammals in puglia.the virological and serological studies previously carried out on arboviruses in italy are reviewed. the presence of antibodies to 11 arboviruses was investigated in the serum of various domestic animals (100 horses, 107 pigs, 102 sheep, 205 goats, 100 cattle and 200 dogs) from some areas of puglia. the techniques are described. the results, given in tables and discussed in detail, support the hypothesis that in this region also there are arboviruses circulating, particularly those of group b.1977201546
virus production with a newly developed microcarrier system.primary cell cultures as well as established lines have been grown on a recently developed microcarrier configuration that overcomes the problem of toxicity attendant on earlier developments in this technology. virus yields from these cells propagated on the new microcarriers have been measured. microcarrier-grown cells, when compared to roller-bottle-grown cells, gave virus yields on a per-cell basis that varied from slightly greater with the sindbis virus-chinese hamster ovary cells and polio- ...1977202193
the influence of immunization on the production of interferon in vivo and in vitro.the present study was undertaken to compare the production of interferon by immunized mice in response to different viral inducers. porton mice were immunized with ndv or a/wr11/57 virus by injecting 6-week-old animals with virus on days 1, 7, and 14. the interferon response was investigated 3 weeks later. compared with controls, the a-immunized mice after stimulation in vivo, produced more interferon when ndv was used as inducer. it was shown in sera as well as in washings of peritoneal cells. ...1977202218
proposal for a common oligosaccharide intermediate in the synthesis of membrane glycoproteins. 1977202393
virus infection of murine teratocarcinoma stem cell lines. 1977202395
envelope antigens of sindbis virus in cells infected with temperature-sensitive mutants.indirect fluorescent-antibody studies of living and fixed chick cells infected with temperature-sensitive mutants of sindbis virus suggest that functional envelope glycoprotein e1 must be inserted through the plasma membrane before e2. pe2 and e2 do not affect the insertion of e1. the experiments also suggest that normal pe2, a glycosylated precursor to e2, reacts with anti-e2 serum; the abnormal pe2 made by a temperature-sensitive pe2 cleavage-defective mutant did not. abnormal e1 proteins made ...1977319257
immunoferritin studies on the multiplication of sindbis virus in chick embryo fibroblasts.replication of sindbis virus chick embryo fibroblasts was studied by means of the immunoferritin technique. virus specific antigens, diffusely distributed in the cytoplasm, were observed at first 3 hours p.i. at the same time in ohter cells ferritin particles in linear arrangement occured at the surface of vesicles. at these places heavily labelled nucleocapsids were observed later on. this means, that the surface of vesicles is a site of assembly of nucleocapsids. maturation of virus takes plac ...1977325950
[antiviral immunity in insects]. 1977332038
[interaction of the sindbis virus and rauscher and friend leukoviruses in primary cultures and subcultures of mouse fibroblasts in the early stages of persistence].the interaction between friend and raucher leukoviruses and sindbis togavirus was studied in primary cultures of mouse fibroblasts and subcultures passaged for 77 days. in primary cultures, two types of virus interactions were observed: neutralism and interference. in interference, the release of the infectious sindbis virus from the cells is blocked. according to electron microscopic observations, its reproduction terminates by formation of virus nucleocapsid. the blocking of the togavirus matu ...1977333760
[antiviral effects of alpha-trihalogenomethylamines and their derivatives]. 1977202821
arboviruses in birds captured in slovakia.virus neutralizing (vn) antibodies against sindbis, tick-borne encephalitis (tbe), west nile (wn), tahyna and calovo viruses were found in birds captured in slovakia. in parallel, sindbis, tbe and wn viruses were isolated from the blood, brain and liver of migrating birds.1977203628
[potential virostatics. 1. quinoxalines]. 1977203954
requirement of cell nucleus for african swine fever virus replication in vero cells.the role of the cell nucleus in the development of african swine fever virus in vero cells has been studied. no viral growth could be detected in enucleated cells under conditions that allow normal development of sindbis virus. furthermore, african swine fever virus dna synthesis was inhibited more than 95% after infection of enucleated vero cells as compared with normal cells.1977403300
sindbis envelope proteins as endogenous acceptors in reactions of guanosine diphosphate-[14c]mannose with preparations of infected chicken embryo fibroblasts.preparations of sindbis-infected chicken embryo fibroblasts incubated with gdp-[14c]mannose and udp-n-acetylglucosamine catalyze the glycosylation of endogenous phospholipids and membrane-associated proteins. the proteins are identified as the viral envelope proteins by precipitation with anti-sindbis antiserum, by comparison with authentic virion glycoproteins on sodium dodecyl sulfate-poly-acrylamide gel electrophoresis, and by comparison of the glycopeptides of the membrane-associated glycopr ...1977404295
togavirus rna: reversible effect of urea on genomes and absence of subgenomic viral rna in kunjin virus-infected cells.electrophoretic analyses showed that no rnase-sensitive rna smaller than the genome was specified by the flavivirus kunjin in infected vero cells during the period of maximum rna and protein synthesis. in contrast, rna extracted from sindbis virus-infected cells under similar conditions included the expected 42s rna (equivalent to the genome) and the smaller 26s (interjacent) rna. treatment of the genome of both togaviruses with 12 m urea produced a reversible (possibly conformational) change; m ...1977597036
arboviruses: persistence and defectiveness in sindbis virus infections. 1977600205
comparison of the carbohydrate of sinbis virus glycoproteins with the carbohydrate of host glycoproteins.the carbohydrate portions of the sindbis virus glycoproteins were compared with the carbohydrate portions of cell surface glycoproteins from uninfected host cells. comparisons of the size of glycopeptides were made using gel filtrations. comparisons of sugar linkages were made by methylation analysis. the conclusion was that the sindbis carbohydrate is similar to a portion of the host carbohydrate. thus, the sindbis carbohydrate structures appear to be structures normally made in the uninfected ...1977616485
free and membrane-bound polyribosomes in bhk cells infected with sindbis virus.the data presented in the paper demonstrate that in bhk cells infected with sindbis virus virtually all the 42s mrna not in nucleocapsid is associated with free polyribosomes, whereas the 26s mrna is distributed between free and membrane-bound polyribosomes. we suggest that the 26s rna polyribosomes are bound to the membranes through the nascent chains of the b1 protein and that a large percentage of 26s rna polyribosomes free in the cytoplasm may be due to the small amount of rough endoplasmic ...1977833938
interaction of sindbis virus glycoproteins during morphogenesis.in cells infected with the sindbis temperature-sensitive mutants ts-23 and ts-10 (complementation group d), which contain a defect in the envelope glycoprotein e1, the precursor polypeptide pe2 is not cleaved to the envelope glycoprotein e2 at the nonpermissive temperature. this defect is phenotypically identical to the defect observed in the complementation group e mutant, ts-20. the lesion in ts-23 is reversible upon shift to permissive temperature, whereas that of ts-10 is not. antiserum agai ...1977833949
how a single sindbis virus mrna directs the synthesis of one soluble protein and two integral membrane glycoproteins.previous work has shown that the 26s rna found in sindbis-infected chicken embryo fibroblasts encodes the three viral structural proteins, one internal protein, core, and two membrane glycoproteins, e1 and e2. this mrna has one initiation site; core, e1, and e2 are derived by proteolytic cleavage. here we show that during infection, the 26s rna is found mainly in membrane-bound polysomes which synthesize all three virion structural proteins. these polysomes are released from the membrane upon tr ...1977837448
effects of udp-glucose addition on the synthesis of mannosyl lipid-linked oligosaccharides by cell-free fibroblast preparations.the pattern of mannosyl lipid-linked oligosaccharides synthesized by cell-free enzyme preparations from cultured fibroblasts is altered substantially when 0.2 mum udp-glucose is added to the incubation medium. inclusion of udp-glucose results in the appearance of a new labeled oligosaccharide, which is 1 or 2 glycose units larger than the lipid-linked oligosaccharide synthesized in the presence of only gdp-mannose (2 mum) and udp-n-acetylglucosamine (20 mum). label from udp-[3h]glucose is incorp ...1977838742
defective interfering particles of sindbis virus. iv. virion rna species and molecular weight determination of defective double-stranded rna. 1977841856
defective interfering particles of sindbis virus. v. sequence relationships between svstd 42 s rna and intracellular defective viral rnas. 1977841857
role of the immune response in recovery from sindbis virus encephalitis in mice.the role of the immune response in recovery from acute encephalitis was studied by using a neuroadapted strain of sindbis virus. intracerebral inoculation of this virus caused fatal disease in weanling mice. passive transfer of homologous immune serum protected mice, but transfer of immune spleen cells and lymph node cells failed to alter mortality. transfers were made 24 hr after intracerebral infection of the recipient, when central nervous system infection was established. the protective fact ...1977845432
evidence for the synthesis of defection interfering particles by aedes albopictus cells persistently infected with sindbis virus. 1977855191
a study of neucleotide sequence homology between the nucleic acids of different alphaviruses. 1977860395
infectious virus-antibody complexes of sindbis virus.infectious virus-antibody complexes were formed when sindbis virus was reacted with antibodies raised against purified viral envelope glycoproteins e1 and e2 as well as against preparations of intact virus. results from rate zonal centrifugation in sucrose gradients of the complex formed with anti-e1 sera showed this complex to be about the same size as virions. a test of virus neutralization, based on direct plaque assay, by antibodies raised in rabbits and mice given virus in complete freund a ...1977870428
envelopments of sindbis virus: synthesis and organization of proteins in cells infected with wild type and maturation-defective mutants.the synthesis and organization of sindbis virus structural proteins was investigated in bhk cells infected with wild-type virus (svhr) or temperature-sensitive (ts) mutants defective in maturation. cells infected with ts-23 or ts-20 (complementation groups d and e) were similar in the polypeptides synthesized at the nonpermissive temperature and differed from svhr-infected cells in that the envelope protein e2 was not cleaved from the pe2 precursor. data from experiments utilizing pulse-chase pr ...1977875134
rat interferons. iv. sialoproteins in rat serum.introduction of virus as inductor of interferon into rats caused a decline in serum levels of sialic acid in blood taken at the time of maximum interferon activity. differences in the acute phase proteins were dependent on the type of virus used for induction. ndv injected intravenously did not lower serum levels of seromucoid, but given together with dmso markedly depressed the content of this protein in the serum. stimulation of interferon production by sindbis virus was accompanied by a signi ...1977879992
strategy of the flavivirus genome: evidence for multiple internal initiation of translation of proteins specified by kunjin virus in mammalian cells. 1977888349
[cellular immune lysis patterns in viral infection]. 1977888574
a comparison of saint louis encephalitis and sindbis virus rna.rna isolated from purified st. louis encephalitis and sindbis virus particles was compared by cellulose cf-11 chromatography, and rnase t1 and pancreatic rnase a digestion. sle rna eluted from the cellulose cf-11 column as a molecule with very little secondary structure, while sindbis appears to have some internal bonding. ribonuclease digestion indicates that sle rna contains 2.4 per cent polyadenylic acid.1977889439
pathogenesis of temperature-sensitive mutants of sindbis virus in the embryonated egg. iii. autologous, homologous, and heterologous interference.two temperature-sensitive (ts) mutants of sindbis virus able to synthetize rna, but not two ts mutants defective in viral rna synthesis, reduced to lethality of the superinfecting heat-resistant parent strain of sindbis virus in embryonated chicken eggs as compared with results in controls. autologous interference (of mutant with parent) was observed under a variety of conditions. time-course studies in one selected system showed that lower titers of superinfecting parent virus were detected in ...1977889615
antibody-dependent, complement-mediated homologous and cross-cytolysis of togavirus-infected cells.the appearance of viral induced antigen(s) on sindbis and semliki forest (sf) virus-infected chick embryo cells is detected with homologous mouse anti-viral antibody-dependent, complement-mediated cytolysis in a 51cr release assay. such antigen(s) is detected within 3 to 4 hr after infection whereas viral cytopathologic effects do not occur until 10 to 12 hr. in addition, significant heterologous cytolysis (anti-sindbis on sf virus-infected cells, or, anti-sfv on sindbis-infected cells) could be ...1977894036
the mechanism of the inactivation of human fibroblast interferon by mechanical stress.interferon derived from human fibroblasts is readily inactivated during agitation and filtration. this inactivation has been shown to be largely a product of mechanical stress, and has been studied in detail by subjecting interferon to controlled shear stress using a rotational viscometer. the possible mechanism of this phenomenon is discussed.1977894266
the continued presence of interferon is not required for activation of cells by interferon. 1977896806
mutants of sindbis virus. ii. characterization of a maturation-defective mutant, ts103. 1977898673
evolution and properties of aedes albopictus cell cultures persistently infected with sindbis virus. 1977898680
nucleolar fragmentation in cells infected with alphaviruses (39886). 1977909877
the significance and nature of defective interfering viruses.deletions in viral genomes appear to be a common occurrence in the replication of all dna and rna viruses which have been adequately studied. such defective genomes can replicate in the presence in the same cell of a helper virus as long as the deletion does not involve the initiation site for genome replication. coinfection of a cell with defective and "normal" infectious virus leads to reduction in the yield of the latter. the nature of di viruses and genomes found in sindbis virus-infected ve ...1977912148
reaction of the protease inhibitor p-nitrophenyl-p'-guanidinobenzoate with sindbis virus. 1977929977
karyotype alterations of bhk-21 cell lines by persistent virus infections i. development of the cell lines and conventional chromosome analysis.from bhk-21 cell cultures inoculated with different viruses cell lines with persistent infection were developed and examined for alterations in their karyotypes. in all cell lines studied, even in those no longer producing infective virus chromosomal breaks and interchanges were observed. besides these effects probably induced directly by the virus infection, a shift in the number of chromosomes was found. based on certain properties of the bhk-21 cell lines carrying a virus infection a hypothes ...1977930469
rat interferons. homologous and heterologus rat serum activity.serum proteins from normal rat serum and induced with sindbis virus were separated on sephadex g-100. interferon activity was studied in a system of homologous rec and heterologous lg cells. proteins of normal serum as well as induced serum emerged in two peaks separated by a deep saddle. four hours after induction, the serum gave two peaks with similar interferon activity in both cell systems. after 8-hour induction, two interferons were also obtained, but activity in the heterologous system wa ...1977931553
susceptibility of chick neural retina to viral multiplication in vitro during embryonic development.decrease in the susceptibility of embryonic chick neural retina cultures to the multiplication of various viruses was observed with increasing age of the embryo. in contrast the retinal cells supported the multiplication of sindbis virus irrespective of the age when they were infected with the viral rna. these results suggest that the restricted multiplication of the viruses observed is due to the modulated inability of the cell to process the adsorbed viruses for subsequent replication.1978620735
reversible inhibition of sindbis virus penetration in hypertonic medium.under hypertonic conditions, the penetration of baby hamster kidney cells by sindbis virus was inhibited. virus became cell associated, but remained susceptible to neutralization by specific antiserum and to removal by elution. when cells were returned to isotonicity, inhibition was reversed.1978621783
synthesis of alphavirus-specified rna.uv irradiation of chicken fibroblasts infected with semliki forest or sindbis virus has been used to investigate the mechanism of synthesis of 42s and 26s rna, the major plus-strand virus-specified rnas formed during the multiplication of standard virus particles. from an analysis of the kinetics of uv inactivation of the synthesis of these two rnas, we conclude (i) that 26s rna is formed by internal transcriptive initiation from a point about two-thirds of the way from the 3' end of the 42s neg ...1978625087
adaptation of an aedes aegypti mosquito cell line to growth at 15 degrees c and its response to infection by sindbis virus.aedes aegypti mosquito cells, usually cultured at 28 to 30 degrees c, were adapted to grow at 15 degrees c. they were designated a. aegypti (c) cells, and had an estimated doubling time of 10 days. sindbis virus (sv) replicated in these cells to peak titres of over 1.0 x 10(9) p.f.u./ml 8 to 10 days after inoculation. these, or about 10-fold lower titres, continued to be produced over a 130 day test period without causing visible cell damage. continuous virus proliferation and the yield of unifo ...1978627872
regulation of the synthesis of sindbis virus-specified rna: role of the virion core protein.cells infected with seven different rna+ mutants of sindbis virus were found to accumulate a virus-specified polypeptide of mol. wt. 144000 (p144) during incubation at the non-permissive temperature, while at the same time synthesis of the virus structural proteins was drastically reduced. mapping of the tryptic peptides of p144 showed that it contained the amino acid sequences of all the virus structural proteins. at the non-permissive temperature cells infected with the same seven mutants (out ...1978632811
effect of low-nacl medium on the envelope glycoproteins of sindbis virus.lowering the nacl concentration of the medium inhibits the release of sindbis virus from infected chicks cells at a stage after the nucleocapsids have bound to the membranes of the infected cells. the failure of trypsin treatment to release the inhibited virus and the ratio of the proteins in the inhibited cells make it seem likely that the inhibited virus is all intracellular. experiments using antisera specific for e1 and e2, the envelope glycoproteins of sindbis, suggest that the inhibitory e ...1978642072
[persistence of sindbis virus in cultures either non-producing or irregularly producing oncornavirus].persistence of sindbis virus (sv) was studied for 9 months in two lines of mouse cell cultures (balb/c) in one of which the genome of endogenous ecotropic oncornaviruses was repressed. the other lines was exogenously infected at the level of plimary culture with rauscher leukemia virus (rlv) and sv and showed gradual inhibition of oncornavirus functions. the presence of oncornavirus type c was not the necessary condition for the development of persistent sv infection, however it influenced the c ...1978645057
altered e2 glycoprotein of sindbis virus and its use in complementation studies.we have detected a sindbis virus variant that contains a smaller-molecular-weight form of the viral glycoprotein e2. the molecular weight of the pe2 precursor and the glycosylation pattern of the smaller e2 are normal, thus indicating that this e2 is formed by an aberrant proteolytic cleavage. the altered e2 was detected in an rna+ temperature-sensitive mutant that was defective in proteolytic cleavage, but the abnormal pe2-to-e2 reaction could be separated from the ts mutation and is not itself ...1978650737
the initial glycosylation of the sindbis virus membrane proteins.the mechanism by which the membrane proteins of sindbis virus are initially glycosylated during growth of the virus in chick cells was studied. the experiments suggest strongly that the 2 viral glycoproteins are glycosylated before release from the polysome and that this glycosylation involves transfer of a large, 1,800 dalton oligosaccharide to the polypeptide chains. the donor of the oligosaccharide is most probably a lipid.1978662921
replication of sindbis virus. vi. poly(a) and poly(u) in virus-specific rna species. 1978664244
effect of ouabain on sindbis virus replication in ouabain-sensitive and ouabain-resistant aedes albopictus cells (singh). 1978664253
[arbovirus multiplication is mosquito cells treated with an interferon inducer]. 1978695524
local resistance of chicken respiratory tract to viral infections. 1978696080
the effect of complement depletion on the course of sindbis virus infection in mice.the course of sindbis virus infection in 12-day-old balb/c mice was altered significantly in animals depleted of the third component of complement (c3) by treatment with purified cobra venom factor (covf). although the same percentage of c3-depleted and normal animals died (30%) after the subcutaneous inoculation of 1000 pfu sindbis virus, the mean day of death was later in c3-depleted mice (8.4 days) than in controls (6.5 days). in addition, morbidity was prolonged in c3-depleted mice. growth o ...1978701795
characterization of a sinbis virus variant with altered host range.a variant of sindbis virus which is much more infectious for mouse cells than the standard virus has been examined for biochemical properties which might be responsible for this biological difference. the variant has a much enhanced ability to adsorb to mouse plasmacytoma (mopc 315) cells, but when these cells were pretreated with heparin, they were able to adsorb the standard virus almost as well as the variant. this suggested that there was a surface charge difference between variant and stand ...1978708264
hexagonal glycoprotein arrays from sindbis virus membranes.freeze-etch electron microscopy of sindbis virus and of glycoprotein arrays derived from sindbis membranes by nonionic detergent treatment shows that the local geometry of glycoprotein-glycoprotein interaction does not depend on the presence of the nucleocapsid.1978722862
evidence for an autoprotease activity of sindbis virus capsid protein. 1978726255
virazole prevents production of sindbis virus and virus-induced cytopathic effect in aedes albopictus cells. 1978741653
inhibition of sindbis virus replication in aedes albopictus cells deprived of methionine. 1978741661
arthropod-borne virus infections in western new guinea (irian jaya): a serological retrospection.a serological investigation, covering many localities throughout western new guinea (irian jaya) in 1958-1961 showed that: a general endemicity of arbovirus infections rather than sporadic epidemics, exists in the southern lowlands--large differences exist in geographical distribution of these viruses especially when comparing coastal areas of the southern, with those of the northern and north western parts of the island--in both arbovirus groups noticeable differences in altitude were observed ...1978749276
[various properties of continuous culture of mosquito cells].the possibility of cultivating a continuous line of aedes aegypti mosquito cells in mitsuhashi and maramorosh medium and medium c-45 was studied. the results of morphological, karyological, and electron microscopic studies of these cells as well as the results of the study of isoenzymes of a. aegypti mosquito cells are presented. replication of sindbis, okhotsky, and baku viruses in these cells was demonstrated.1978749343
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