| properties of semliki forest virus nucleocapsid. | the nucleocapsid of the semliki forest virus is composed of 34% rna and 66% protein, or one rna and about 240 capsid protein molecules. the particle is spherical, with a diameter of 38--39 nm. if the nucleocapsid is exposed to slightly acid ph (6.4--5.6) it undergoes a structural change and is contracted to a 32 nm state. a similar contraction can be effected by rnase treatment, in this case, however, in connection with a loss of rna. treatment of the nucleocapsid with 0.2 mm sds results in diss ... | 1975 | 1605 |
| enhancement of interferon induction in mice by polycationic modified polypeptides. | combined intraperitoneal treatment of mice with poly i: c and a polycationic modified polypeptide (poly-dmae-glutamine) was investigated. it was established that the presence of appropriate amounts of poly-dmae-glutamine produced markedly enhanced serum interferon levels as compared to those produced by poly i: c alone. similar combinations injected into mice produced full protection against lethal doses of mouse-virulent semliki forest virus. | 1976 | 5874 |
| some properties of togavirus hemagglutinin studied with the aid of kaolin-adsorbed virus. | acidification (at ph 5.75) of semliki forest virus and west nile virus suspensions completely eliminated their hemagglutinating activity within several minutes, but did not affect their infectivity or change their ability to absorb homologous hemagglutination-inhibition antibodies. in order to assay antibody absorption it was necessary to remove all of the immune complex from the reaction mixture, because the immune complex inhibited additional hemagglutinin. removal of the immune complex can be ... | 1976 | 9052 |
| structure and assembly of lipid-containing viruses, with special reference to bacteriophage pm2 as one type of model system. | the simpler lipid-containing viruses (influenza, semliki forest, pm2) may have a phospholipid bilayer sandwiched between an outer shell of protein and an internal nucleocapsid possessing helical or icosahedral symmetry. extensive physical and chemical studies have enabled us to form a more detailed picture of the structure of bacteriophage pm2 and controlled stepwise degradation of the virion has helped us to localize the four viral proteins. the surface protein (ii) of pm2 is basic and interact ... | 1976 | 13436 |
| 6-mfa, an antiviral agent from aspergillus ochraceus atcc 28706: influence of body weight and mineral oil administration of the antiviral activity in mice. | sera obtained from mice treated with 6-mfa, an antiviral agent from aspergillus ochraceus atcc 28706 showing high interferon activity, could be transferred to healthy animals to make them resistant to semliki forest virus (sfv) infection. body weight of mice directly influenced, within limits, the proportion of treated mice surviving challenge virus infection as well as interferon production. mineral oil (liquid paraffin, b. p.) administered prior to 6-mfa increased both the level of interferon ... | 1977 | 15439 |
| effect of streptovaricin on the incorporation of uridine into cellular and viral rna. | poxvirus replication is inhibited by streptovaricin. the most readily observed effect is the inhibition of incorporation of 3huridine into viral mrna, suggesting an inhibition of rna synthesis. streptovaricin also inhibits the incorporation of 3huridine into cellular rna but not as severely as viral rna. on the other hand, 3huridine incorporation into the rna of semliki forest virus (sfv), which contains a positive strand rna genome, does not seem to be inhibited by streptovaricin. the inhibitor ... | 1977 | 16701 |
| the role of the nucleus in the replication of measles virus. | the replication of measles and sspe viruses in enucleate bsc-1 cells was measured by plaque assay, and the synthesis of virus-specific antigen was measured by indirect immunofluorescence. titres of infectious virus produced in enucleate cells at 24 hours post inoculation (p.i.) were consistently 100-fold less, and the number of enucleate cells containing virus antigen at 30 hours p.i. was 10-fold less, than in nucleate control cultures. enucleate cells at this time had 30% of the protein synthet ... | 1977 | 18925 |
| chromatographic separations of alphavirus strains by hydroxylapatite. | hydroxylapatite column chromatography methods were developed to characterize selected alphavirus populations. different conditions of ph and phosphate molarity were required to obtain satisfactory elution profiles and separations for western equine encephalomyelitis virus strains, compared with eastern equine encephalomyelitis virus and semliki forest virus strains. raising the ph of the buffers effected earlier elutions of all viruses. selection of phosphate gradients with more gentle slopes an ... | 1977 | 20452 |
| simple method for preparation of immune sera to envelope and nucleocapsid antigens of semliki forest virus. | immune sera to the envelope and nucleocapsid components of zaisan 260 and r 16225 strains of semliki forest virus (sfv) were prepared with the use of disrupted, partially purified virus. | 1977 | 20771 |
| novel antiviral activity found in the media of sindbis virus-persistently infected mosquito (aedes albopictus) cell cultures. | aedes albopictus (mosquito) cells persistently infected with sindbis virus for a period of 6 months release into the medium a low-molecular-weight material capable of specifically reducing the yields of sindbis virus during the "acute phase" of infection in mosquito cells. the antiviral activity was produced in detectable levels at 3 days after infection, and its concentration in the extracellular medium increased thereafter. the antiviral activity was inactivated by treatment with the enzyme pr ... | 1979 | 34732 |
| haemolysis by two alphaviruses: semliki forest and sindbis virus. | purified preparations of semliki forest (sfv) and sindbis virus haemolyse red blood cells from several species of animals and birds. the optimal haemolysis by sfv was obtained at ph 5.8 with 1-day-old chick erythrocytes incubated at room temperature. considerable variation in haemolytic activity was observed between different virus preparations purified by different methods. the haemolytic activity of sfv was inhibited by antisera against whole virus or isolated envelope proteins but not with an ... | 1979 | 39116 |
| quantitative and rapid assays of togaviruses by immunofluorescence. | for the quantitative assay of selected togaviruses, suspensions of bhk cells were inoculated with virus and grown in spinner cultures. at intervals, dependent on the growth characteristics of the viruses, about 10(3) cells were centrifuged on to microscope slides and then stained with fluorescent antibody. for rapid demonstration (2--3 hr) of specific viral antigens, virus was bound in successive dilutions onto microscope slides and stained. binding of specific anti-virus antibodies in both meth ... | 1979 | 40420 |
| antiviral effect of 3-[bis-(2-hydroxyethyl)-amino]-acetophenone-[4,5-diphenyl-oxyazolyl-(2)]hydrazone (imet 98/69) in mice. | the potential in vivo antiviral activity of 3-[bis-(2-hydroxyethyl)-amino]-acetophenone-[4,5-diphenyl-oxazolyl-(2)]-hydrazone (imet 98/69) was evaluated on model infections in mice. animals treated subcutaneously (s.c.) with 1 mmole of the drug per kg body weight once daily for five days were significantly protected against a lethal infection with cardioviruses, semliki forest virus and vaccinia virus. in influenza a and b virus models no antiviral activity was observed either after s.c. or oral ... | 1979 | 44666 |
| early synthesis of semliki forest virus-specific proteins in infected chicken cells. | cells preinfected with fowl plague virus followed by treatment with actinomycin d are a suitable system for studying early protein synthesis in cells infected with semliki forest virus. one and one-half hours after superinfection, three new nonstructural proteins (nvp) were detected: nvp 145, nvp, 112, and nvp 65. they appeared in parallel with a low incorporation of mannose at the beginning of the infectious cycle. behavior on chasing suggested a precursor relationship of nvp 112 to the envelop ... | 1976 | 59814 |
| the inactivation of polio-, coxsackie- and semliki forest viruses by a tri-iodinated benzamido-derivative of glucose. | | 1976 | 64225 |
| the effect of sodium metrizoate, d-glucosamine and n-acetylglucosamine on the infectivity of polio-, coxsackie, semliki forest- and measles virus in vitro [proceedings]. | | 1976 | 66022 |
| interaction of mouse peritoneal macrophages with different arboviruses in vitro [proceedings]. | | 1976 | 66026 |
| reduced choline-acetyltransferase activity in scrapie mouse brain. | | 1978 | 79111 |
| solid phase indirect radioimmunoassays for the rapid diagnosis of sindbis virus antigen. | indirect radioimmunoassays have been developed for the rapid detection of sindbis virus. dilutions of sindbis virus from tissue culture fluids have been immobilized and allowed to react with rabbit anti-sindbis virus antibodies. the bound antibodies were assayed either by 125i-labelled anti-rabbit igg-antibodies or alternatively by addition of human complement and 125i-labelled anti-human c1q antibodies or 125i-labelled protein a. | 1978 | 84855 |
| inhibition of interferon production by retinoic acid (vitamin a acid). | the production of interferon was employed to study the site and mechanism of action of retinoic acid (vitamin a). the data is consistent with a site of action of retinoic acid at the gene level, since it appears that interferon production is suppressed at the transcriptional step by a retinoic acid-induced protein. evidence for this is as follows: (a) the effect of retinoic acid is probably on an early cellular function associated with interferon production rather than an effect on the inducer ( ... | 1977 | 99833 |
| messenger ribonucleoprotein complexes containing in vitro-synthesized 26s and 42s semliki forest virus rna. | an extract derived from semliki forest virus (sfv) infected cells is described which catalyzes the synthesis of virus-specific rnas. the newly-synthesized 26s and 42s rnas are found complexed with protein as messenger ribonucleoproteins (mrnps). these mrnps either are non-membrane bound or are associated with large cytoplasmic lipoprotein membranes, and they are found as free mrnps as well as mrnps bound to ribosomal subunits, ribosomes, and polysomes. following treatment with tween 40 and deoxy ... | 1979 | 110291 |
| comparison of the structural properties of sindbis and semliki forest virus nucleocapsids. | the envelope spikes of sindbis and semliki forest virus are arranged in a t = 4 icosahedral surface lattice and, by deduction, it has been suggested that the nucleocapsid proteins are similarly arranged. after treatment of the virions with a non-ionic detergent the released nucleocapsids sediment in sucrose gradients at about 160s and 150s and have densities in cscl of 1.42 g/ml and 1.425 g/ml, respectively, for sindbis and semliki forest virus. at ph 6.0 sindbis nucleocapsids do not contract li ... | 1979 | 118237 |
| adoptive transfer of cross-protection among alphaviruses in mice requires allogeneic stimulation. | cell-mediated (t-effector cell) immunity is proposed as playing the major role in cross-protection between sindbis and semliki forest viruses, which are alphaviruses that do not elicit cross-neutralizing antibodies. in adoptive transfer experiments, t-cells from spleens of sindbis virus-immunized mice were found to confer specific cross-protection to semliki forest virus upon recipient mice. this cross-protection was observed in the outbred icr strain of mice and when transfers were made between ... | 1979 | 157981 |
| two different mechanisms of the inhibition of the multiplication of enveloped viruses by glucosamine. | | 1975 | 163046 |
| virus development in enucleate cells: echovirus, poliovirus, pseudorabies virus, reovirus, respiratory syncytial virus and semliki forest virus. | a group of rna viruses, echovirus, poliovirus, reovirus, respiratory syncytial virus and semliki forest virus have been examined for ability to grow in enucleate african green monkey kidney (bsci) cells. semliki forest virus produced an almost normal yield of virus but poliovirus, echovirus, reovirus and respiratory syncytial virus, although showing clear evidence of virus replication when compared with a nuclear dna virus (pseudorabies virus) gave much lower yields than those from nucleate cell ... | 1975 | 163289 |
| comparative study of the protein kinase associated with animal viruses. | | 1975 | 166492 |
| the enhancing effect of copper, nickel, and cobalt ions on plaque formation by semliki forest virus (sfv) in chicken embryo fibroblasts. | in cultured chicken embryo fibroblasts treated with copper-(copper cation 10-minus 3.5-10-minus 5 m), nickel and cobalt salts an enhancement of the plating efficiency of semliki forest virus could be observed. this augmented plaque formation was most probably due to a higher adsorption rate of virions to the cell surface under the influence of the transition metal ions. the plating efficiency of west nile virus in chicken-embryo fibroblasts and, to a lesser degree, of poliovius type 1 and 2 in k ... | 1975 | 167680 |
| a new method for monitoring subclinical virus infections of the central nervous system in mice. | the course of a subclinical virus infection of the central nervous system (cns) of mice has been followed by measuring spontaneous motor activity using animex equipment. a significant drop in activity occurred on the 5th and 6th day after inoculation with the a774 (avirulent) strain of semliki forest virus (sfv) before histological changes were apparent but at the same time as maximum brain virus titre. the relationship of the fall in activity to changes in the pattern of weight gain, food and w ... | 1975 | 169870 |
| sindbis virus inhibits phosphatidylcholine biosynthesis in bhk-21 cells. | sindbis virus inhibits the incorporation of [methyl-3h]choline into the phospholipids of bhk-21 cells and also inhibits the activity of the enzyme that catalyzes the final reaction involved in phosphatidylcholine biosynthesis (cytidine diphosphate-choline:1,2-diacylglycerol cholinephosphotranferase; ec 2.7.8.2). | 1975 | 170413 |
| [sensitivity of various primate cells and animal viruses to the antiviral activity of human leukocyte interferon (author's transl)]. | u cells (a permanent, human amnion cell line) were protected against infection with semliki forest virus (sfv) by human interferon (hif) from peripheral leukocytes. despite the usual genus-specific action of interferons, mouse l929 cultures (a permanent mouse fibroblast cell line) were also protected by hif. the antiviral action of hif in six other primate cell cultures was also examined. it is of interest that two lymphoblastoid cell lines, rpmi1788 and kaplan, were insensitive to hif. the sens ... | 1975 | 170886 |
| inhibition of phosphatidylethanolamine biosynthesis in baby hamster kidney-21 cells infected with semliki forest virus. | semliki forest virus inhibits phosphatidylethanolamine biosynthesis in baby hamster kidney-21 cells 6 h after infection. viral infection reduced the incorporation of [1,2-14c]-ethanolamine into intact cells by approximately 50%. a similar reduction in the activity of the ethanolaminephosphotransferase (ec 2.7.8.1) was also observed. the apparent km for cdpethanolamine was 60 mum for the microsomal enzymes from infected or mock-infected cells. in addition, exogenous diglyceride only stimulated by ... | 1975 | 171043 |
| initiation of synthesis of the structural proteins of semliki forest virus. | | 1975 | 171418 |
| viral replication and interferon production in fetal and adult ovine leukocytes and spleen cells. | peripheral blood leukocyte and spleen cell cultures derived from adult sheep and from third-trimester (107 to 145 days of gestation) and second-trimester (70 to 98 days of gestation) fetal lambs were examined for their ability to support viral replication and to produce interferon. bluetongue virus, herpesvirus hominis type 2, and chikungunya virus failed to replicate in either leukocyte or spleen cell cultures derived from adult ewes or in cultures from second- or third-trimester fetal lambs. s ... | 1975 | 172452 |
| the genome of equine arteritis virus. | | 1975 | 173077 |
| effect of tetraethyl thiuram disulfide (disulfiram) on the multiplication of enveloped viruses. | disulfiram at concentrations between 0.1 and 0.3 mm inhibits the multiplication of semliki forest virus (sfv), fowl plague virus (fpv), newcastle disease virus (ndv), vesicular stomatitis virus (vsv), and pseudorabies virus (prv), when administered 1 hour before and during adsorption. there is, however, no inhibition of virus multiplication, when the drug is added after adsorption onto chick embryo cells. disulfiram interferes neither with the receptors of the virus nor of erythrocytes, and it d ... | 1975 | 173261 |
| anti-viral activity of single-stranded homopolynucleotides against encephalomyocarditis virus and semliki forest virus in adult mice without interferon induction. | single administrations of poly c or poly i are anti-viral against infections of encephalomyocarditis (emc) and semliki forest virus (sfv) in mice but poly u and poly a are not. the degree of protection is dose-dependent and mice which die do so at a later time when untreated controls even in a strain of mouse in which the time of death is not dependent on the dose of virus given. no circulating interferon is found after treating mice with poly c or poly i even at polynucleotide doses which give ... | 1976 | 173799 |
| inhibition of cellular protein synthesis by simultaneous pretreatment of host cells with fowl plague virus and actinomycin d: a method for studying early protein synthesis of several rna viruses. | a method is described for analysis of viral protein synthesis early after infection when minute amounts of viral proteins are effectively concealed by large amounts of produced host-specific proteins. the method is superior to a radioimmune assay, since all virus-induced proteins can be measured independent of their immunological reactivity. host-specific protein synthesis can be suppressed by infection with fowl plague virus. addition of actinomycin c 1.25 h postinfection does not prevent this ... | 1975 | 173875 |
| translation of the genes for the structural proteins of alphaviruses. | synthesis of the structural proteins of semliki forest virus by a cell-free system derived from mouse l-cells and programmed by intracellular 26s rna is described. this polycistronic rna is translated in vitro into several discrete polypeptides. the identity of these polypeptides as the structural proteins of the virus was established by polyacrylamide gel electrophoresis, immunoprecipitation and tryptic peptide mapping. studies using formyl--e135s]methionyl-trnaf as precursor, and using diphthe ... | 1975 | 173941 |
| effect of infection with enveloped viruses on nucleotide metabolism. | | 1976 | 176807 |
| 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 ... | 1976 | 177724 |
| 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. | 1976 | 178280 |
| fluorosugars inhibit biological properties of different enveloped viruses. | both 2-deoxy-2-fluoro-d-glucose and 2-deoxy-2-fluoro-d-mannose were found to be potent inhibitors of the synthesis of infectious semliki forest and fowl plague virus in chicken embryo cells and also of pseudorabies virus grown in rabbit kidney cells. it was found that the pseudorabies virus-mediated cell fusion and the synthesis of functional hemagglutinin of fowl plague virus were blocked. in all cases the 2-deoxy-2-fluoro-d-mannose-caused inhibition was stronger than the 2-deoxy-2-fluoro-d-glu ... | 1976 | 178923 |
| suppression of glycoprotein formation of semliki forest, influenza, and avian sarcoma virus by tunicamycin. | tunicamycin, a new antibiotic, halts the formation of physical particles of semliki forest and fowl plague virus, whereas avian oncornavirus particles which show a reduction in infectivity and do not contain detectable labeled glycoprotein are released in the presence of the drug. in semliki forest virus-infected cells only the protein moieties of the glycoproteins could be labeled. in cells infected with fowl plague and avian sarcoma virus neither intact glycoproteins nor their protein moieties ... | 1976 | 184299 |
| anti-viral activity against encephalomyocarditis virus and semliki forest virus and acute toxicity of poly i and poly c administered sequentially to mice. | mice are protected against lethal intraperitoneal and intravenous infection by encephalomyocarditis virus and semliki forest virus by sequential treatment with poly i followed by either polyc or poly5-hydroxyc without production of interferon when the treatments are 4 or more hours apart and by the intraperitoneal or intravenous routes. maximum protection occurs around 4 hours before infection and is still significant 20 hours after infection. treatments with combinations of other homoribopolynu ... | 1976 | 184760 |
| bis-basic-substituted polycyclic aromatic compounds. a new class of antiviral agents. 7. bisalkamine esters of 9-oxoxanthene-2,7-dicarboxylic acid, 3,6-bis-basic ethers of xanthen-9-one, and 2,7-bis(aminoacyl)xanthen-9-ones-xanthenes, and -thioxanthenes. | 3,6-bis[2-(dimethylamino)ethoxy]-9h-xanthen-9-one dihydrochloride (4, rmi 10874da) and 1,1'-(9h-xanthene 2,7-diyl)bis[2-(dimethylamino)ethanone] dihydrochloride (16, rmi 11513da) were found to prolong survival of mice infected with lethal challenges of encephalomyocarditis (emc) virus. they were effective by oral as well as subcutaneous administration and showed broad-spectrum antiviral activity. they were selected for preclinical evaluation from the five series of compounds named in the title t ... | 1976 | 185385 |
| antiviral activity of bl-3849a, a low-molecular-weight oral interferon inducer. | oral administration of bl-3849a to adult mice resulted in peak serum interferon titers of 4,000 units from 15 to 30 h after administration, with detectable levels persisting until 48 h. after intraperitoneal (i.p.) inoculation, peak serum interferon titers of 1,000 to 3,000 units were noted between 9 and 18 h. multiple injections of the inducer by either route resulted in a marked decrease in the interferon response with each successive dose. in mice infected intranasally with the rochester mous ... | 1976 | 185953 |
| location of the sequences coding for capsid proteins vp1 and vp2 on polyoma virus dna. | the 19s and 16s polyoma virus late mrnas have been separated on sucrose-formamide density gradients and translated in vitro. the 16s rna codes only for polyoma capsid protein vp1, while the 19s rna codes in addition for capsid protein vp2. since the 19s and 16s species have been previously mapped on the viral genome, these results allow us to deduce the location of the sequences coding for vp1 and vp2. comparison of the chain lengths of the capsid proteins with the size of the viral mrnas coding ... | 1976 | 186193 |
| 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 ... | 1976 | 187719 |
| interferon induction by radioprotective mercaptoalkylamines and derived thiophosphates. | radioprotective thiols (five mercaptoalkylamines and four derived thiophosphates) induced interferon and resistance to virus infection. interferon production occurred in human and mouse nonlymphoid cell cultures. one of the thiols, s,2-aminoethylisothiourea, given intraperitoneally, protected mice against two unrelated viruses--semliki forest virus and herpesvirus hominis type 1. two structurally different radioprotective thiols--the disulfide cystamine and l-cysteine--were unable to induce the ... | 1977 | 188764 |
| [antiviral agents. xix. amantadine derivatives and several others]. | the synthesis and pharmacological activity of several adamantane derivatives and analogs of tilorone are described as part of a systematic research on potential antiviral compounds and/or interferon inducers. | 1977 | 192582 |
| [hemagglutinating activity of various viruses on trypsinized erythrocytes]. | mengo, vesicular stomatitis and semliki forest viruses titered with trypsin modified mouse, goose, pigeon and human erythrocytes show ha titers 2-32 fold higher than with the same untreated cells. | 1976 | 192623 |
| suppressed response to interferon inducation in mice infected with encephalomyocarditis virus, semliki forest virus, influenza a2 virus, herpesvirus hominis type 2, or murine cytomegalovirus. | mice infected with encephalomyocarditis virus, semliki forest virus, influenza a2 virus, herpesvirus hominis type 2, or murine cytomegalovirus developed a state of hyporeactivity to interferon induction. in general, the capacity of infected animals to produce interferon in response to inducers became progressively impaired during the course of infection. the severity and time of onset of hyporeactivity, however, were dependent upon the inducer and the nature of the viral infection. during viral ... | 1977 | 192804 |
| immunomodulation of host resistance to experimental viral infections in mice: effects of corynebacterium acnes, corynebacterium parvum, and bacille calmette-guérin. | resistance to a representative group of experimental virual infections in mice was significantly enhanced by nonspecific modulation of host defense mechanisms. corynebacterium acnes, corynebacterium parvum, and bacille calmette-guérin were effective in enhancing host resistance. animals treated seven to 10 days before inoculation of virus were protected against a lethal infection with herpesvirus hominis type 2, encephalomyocarditis virus, murine cytomegalovirus, or semliki forest virus. the pro ... | 1977 | 192811 |
| 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 ... | 1977 | 194918 |
| high sensitivity of c3h mouse embryo-derived cell line to the antiviral activity of interferon. | | 1977 | 195290 |
| effect of tunicamyein on the morphogenesis of semliki forest virus and rous sarcoma virus. | semliki forst virus (sfv) infected chick embroyo cells (cec) incubated in the presence of tunicamyein, a drug which specifically inhibits glycosylation, were studied under the electron microscope. no extracellular virions were produced although intracellular viral nucleocapsids in paracrystalline form were detected. under these conditions the structures, referred to as type 1 and 2 cytopathic vacuoles (cpv-1 and cpv-2, respectively) as well as membraneous spherules at the plasma membrane could s ... | 1977 | 200200 |
| a comparison of brain lysosomal enzyme activities in four experimental togavirus encephalitides. | | 1978 | 204753 |
| polymeric drugs: direct compared with indirect inhibition of leukemia virus replication in mice. | | 1978 | 205772 |
| prostaglandin restoration of the interferon response of hyporeactive animals. | virus-infected animals and those bearing various types of malignancies progressively lose the ability to respond to interferon inducers. the interferon response of virus-infected animals could be restored to normal levels when inducers were administered with certain prostaglandins. this suggests that prostaglandins may enhance the therapeutic efficacy of interferon inducers as antiviral and antineoplastic agents. | 1978 | 208154 |
| early events in influenza virus multiplication. ii. penetration of virus into cells at 4 degrees. | | 1978 | 208249 |
| inactivation of cytomegalovirus and semliki forest virus by butylated hydroxytoluene. | butylated hydroxytoluene (bht) is an antioxidant that is widely used in foods because it prevents spoilage by delaying degradation of lipid components. this hydrophobic compound inactivated human and murine cytomegalovirus (cmv) and semliki forest virus (sfv). both human and murine cmv were inactivated more than 90% by 40 microgram of bht/ml after incubation for 1 hr at 37 c. under the same conditions, svf was inactivated about 75%, whereas poliovirus, which does not contain lipid membrane as a ... | 1978 | 210237 |
| [interferonogenic and antiviral activity of the double-stranded replicative form of phage f2 rna in tissue culture and on animals]. | biological activity of a new natural interferon inductor, the replicative rna form of phage f2 (rff2) was studied. a possibility of using rff2 for production of highly active interferon under conditions of superinduction providing an increase in the interferon yield by to 256--512 times as compared to the control samples was shown. the protective interferonogenic and antiviral effect of rff2 in mice infected with semliki forest virus (sfv) and tickborne encephalitis virus (tbev) was studied on a ... | 1978 | 210710 |
| protection of mice against viral infection by corynebacterium parvum and bordetella pertussis. | mice could be significantly protected against infection with herpes simplex virus (hsv) by i.p. or i.v. injection of killed corynebacterium parvum 7 days before infection. this protection was seen in inbred strains of mice with a different degree of sensitivity to hsv and after both i.p. and i.v. infection. resistant mice immunosuppressed by x-irradiation and showing an increased susceptibility to hsv could also be protected by a previous injection of c. parvum. elevated levels of interferon wer ... | 1978 | 212522 |
| formation of protein micelles from amphiphilic membrane proteins. | the membrane penicillinase (penicillin amido-beta-lactamhydrolase, ec 3.5.2.6) from bacillus licheniformis, the semliki forest virus spike proteins, and the sendai virus glycoproteins have each been isolated as soluble protein aggregates that are virtually free of lipid and detergent. the sedimentation coefficients of the complexes were 18 s, 29 s, and 43 s, respectively. mixed aggregates containing both the virus glycoproteins and the penicillinase could also be formed. such protein micelles ma ... | 1978 | 214782 |
| induction of chicken interferon by avian infectious bronchitis virus. | the ability of nine strains of avian infectious bronchitis virus (ibv) to induce chicken interferon has been investigated using semliki forest virus for the tests. the beaudette, h120 and connecticut 46 strains induced interferon in the allantoic fluids of embryonated hens' eggs, the highest titre (1 : 30) being associated with beaudette; but these as well as the massachusetts m-41 and h52 strains failed to yield interferon in primary monolayer cultures of chick kidney cells as did all nine stra ... | 1978 | 214833 |
| translocation of a hydrocarbon fluorescent probe between epstein-barr virus and lymphoid cells: an assay for early events in viral infection. | translocation of the hydrocarbon fluorescent probe diphenylhexatriene (dph) between membranes was studied by fluorescence polarization (p) analysis. first, using a model system, the high p value (0.324) of dph-labeled cholesterol/phosphatidylcholine liposomes and the low p value (0.157) of dph-labeled phosphatidylcholine liposomes allowed detection of dph translocation between interacting liposomes. this was monitored by the change in p in either direction. early events during cell-virus interac ... | 1978 | 217012 |
| [characteristics of the response of mice with temporary immunodepression to the administration of live or inactivated vaccine against tick-borne encephalitis]. | mice with immunity defects caused by administration of cyclophosphane were inoculated with an inactivated vaccine or langat virus (tp-21 strain) considered to be an approximate model of the vaccine against tick-borne encephalitis. in mice with depressed immune response, the asymptomatic infection caused by langat virus turns into acute form and encephalitis with a fatal outcome develops in 86--100%. pre-treatment with inactivated tick-borne encephalitis vaccine did not protect the animals with t ... | 1979 | 217179 |
| selective inhibition of protein synthesis in virus-infected mammalian cells. | a number of translation inhibitors were tested for their effects on both control and encephalomyocarditis virus-infected mouse 3t6 cells. the virus-infected cells were specifically inhibited by gougerotin, edeine, and blasticidin s, whereas these drugs failed to penetrate into uninfected cells. inhibition of infected cells by gougerotin became apparent when the synthesis of viral proteins commenced, suggesting that the latter process is accompanied by a permeability change in the cells that allo ... | 1979 | 219211 |
| restricted replication of two alphaviruses in ricin-resistant mouse l cells with altered glycosyltransferase activities. | two mouse l cell variant lines (cl 3 and cl 6) selected for resistance to the toxic plant lectin ricin were restricted in their ability to replicate the two alphaviruses sindbis virus and semliki forest virus. cl 3 cells have been shown to exhibit increased cmp-sialic acid:glycoprotein sialyltransferase and gm3 synthetase activities, whereas cl 6 cells have been shown to contain decreased udpgalactose:glycoprotein galactosyltransferase and udp-n-acetylglucosamine:glycoprotein n-acetylglucosaminy ... | 1979 | 219229 |
| [antiviral activity of interferon and its inducers in human lymphoblastoid and somatic cells]. | the antiviral effect of interferon inductors, such as poly-i--poly-c, phage f2 rna replicative form and low molecular inductor gsn and their influence on cellular dna synthesis were studied in the cultures of lymphoblastoid (inplanting lines raji namalva) and somatic human cells. the semliki forest virus used as the test organism multiplicated well in cells raji accumulating up to 9 lg bou/ml. the two-strand rna was less active in the lymphoid cells than in the somatic ones. gsn was 10 times mor ... | 1979 | 220908 |
| increase of interferon antiviral activity by exogenous cyclic adenosine-3':5'-monophosphate (camp). | some effects of camp on replication of semliki forest virus in chick embryo fibroblast cell cultures are described. depending on concentration, the incorporation of [3h]-uridine into viral rna or the formation of plaque-forming units is inhibited; the highest concentration tested was 8 mm. cyclic amp has an effect of its own and increases the interferon action in the lower concentration ranges of interferon (up to 1 unit/ml). the effect of cyclic amp is fast, needs no induction and is also visib ... | 1979 | 221234 |
| effects of amphotericin b and its methyl ester on the antiviral activity of polyinosinic:polycytidylic acid. | since the macrolide polyene antibiotics, amphotericin b (amb) and its methyl ester (ambme), augment interferon production by polyriboinosinic:polyribocytidylic acid [poly(i):poly(c)] in vitro, experiments were undertaken to determine how amb and ambme affect the antiviral activity of poly(i):poly(c) and interferon. ambme increased the direct antiviral activity of poly(i):poly(c) 10(2)-to 10(4)-fold in l929, flow 6000, and t98g cells. viral replication, measured by either direct plaque formation ... | 1979 | 225986 |
| effect of antiviral lipids, heat, and freezing on the activity of viruses in human milk. | semliki forest virus (sfv), herpes simplex virus type 1 (hsv-1), coxsackievirus b4, and cytomegalovirus (cmv) were added to human milk, which was then subjected to treatments that approximated those required for the decontamination or storage of milk. boiling was the only treatment that eliminated these viruses from the milk. pasteurization (at 62.5 c for 30 min) did destroy cmv, but the other viruses could still be detected. all of the viruses except hsv-1 were detectable after the contaminated ... | 1979 | 227969 |
| arbovirus infections in sarawak, october 1968-february 1970: getah virus isolations from mosquitoes. | 14 strains of getah virus were isolated from a variety of mosquito species collected in sarawak between october 1968 and february 1970. ten strains were isolated from c. tritaeniorhynchus 7 of them at k. tijirak. single strains were isolated from c. gelidus, c. pseudovishnui, m. bonneae/dives and aanopheles species. 6 of the isolates were obtained in october 1968 when japanese encephalitis, tembusu and sindbis viruses were also very active. the available evidence suggest that getah virus in sara ... | 1975 | 238314 |
| [identification of a group a arbovirus isolated in the far east]. | strains nos. 296 and 260 isolated from aedes vexans and culex pipiens mosquitoes in the ussr far east in 1971 and 1973, respectively, were identified. the size of the viruses was found to be about 50 nm. both strains were pathogenic for 2--3-day-old and 3--4-week-old mice by the intracerebral, subcutaneous and intraperitoneal routes, agglutinated goose red blood cells at the optimal ph 6.0. the strains were identical to each other and by their antigenic structure were classified as semliki fores ... | 1975 | 240231 |
| human (hla-a and hla-b) and murine (h-2k and h-2d) histocompatibility antigens are cell surface receptors for semliki forest virus. | the proteins coded for by the hla-a and hla-b loci in man and the h-2k and h-2d loci in mice were identified as cell surface receptors for semliki forest virus. this conclusion is based on the following observations: (i) water-soluble octamers of viral coat proteins inhibit the complement-dependent cytotoxicity of antibodies directed against h-2k and h-2d antigens in mouse cells. (ii) isolated detergent-soluble hla-a and hla-b antigens reconstituted in lipid vesicles inhibit the binding of viral ... | 1978 | 278998 |
| the effect of cordycepin on the multiplication of semliki forest virus and on polyadenylation of viral rna. | cordycepin (3'-deoxyadenosine), at a concentration of 20 microgram/ml, has a marked effect on semliki forest virus multiplication. the appearance of plaque forming units is delayed by about 2 hours and the yield greatly reduced. the incorporation of [3h] uridine into intracellular viral rnas reaches less than 50 per cent of controls. however, no specific effect on poly (a) synthesis could be detected. the binding efficiency of viral rnas on nitrocellulose membranes and poly (u) sepharose is not ... | 1977 | 302113 |
| effective subunit vaccines against an enveloped animal virus. | | 1978 | 310517 |
| cellular immunity against semliki forest virus in mice. | intracutaneous immunization of balb/c mice with purified inactivated semliki forest virus resulted in cellular immunity without detectable antibodies. the animals were protected against subcutaneous challenge, from which the challenge virus spreads slowly. after intraperitoneal challenge, which permits a rapid virus spread, the protection was marginal. stimulation of the intraperitoneal cell population with thioglycolate before challenge resulted in complete protection. the protection could be t ... | 1979 | 311341 |
| the responses of nude-athymic mice to nominally avirulent togavirus infections. | following intraperitoneal infection by an avirulent strain of semliki forest virus, athymic nude mice showed almost normal clearance of viraemia and a transitory peak of antibody activity at 5 to 9 days which fell to less than about 0.1% of the normal antibody activity from the 14th day. when nude mice received a transfer of normal spleen cells from sex-matched litter mates at 1 day before infection, a pattern of high and continous antibody synthesis was established for at least the following 7 ... | 1979 | 311822 |
| virus spike protein complexes and virosomes as effective subunit vaccines. | | 1979 | 313692 |
| in vitro heterologous cytotoxicity by t effector cells from mice immunized with sindbis virus. | an in vitro correlate of cell-mediated cross-protection among alpha-viruses was demonstrated by cytotoxicity of sindbis-immune spleen cells from mice to both sindbis and semliki forest virus (sfv)-infected target cells. this cytotoxicity was shown to be mediated by the t cell population of the spleen and was independent of the presence of macrophages or b cells. the time when the level of the lymphocyte-mediated cytotoxicity (lmc) to sfv-infected cells was maximal coincides with the time when im ... | 1979 | 314471 |
| cross protection among togaviruses in nude mice and littermates. | after immunization with sindbis virus, t-cell deficient nude mice, compared to normal littermates, were equally protected against challenge with sindbis virus. however, the nude mice showed about one-tenth the protection observed with normal littermates after challenge with semliki forest virus at a dose of 100 ld50. this consistent with our previous interpretation that sensitized t-cell populations play a major role in cross protection between the two togaviruses. the remaining low level of spe ... | 1979 | 316446 |
| reconstitution of purified detergent-soluble hla-a and hla-b antigens into phospholipid vesicles. | purified detergent-soluble human histocmpatibility antigens (hla-a and hla-b) were reconstituted into phospholipid vesicles by mixing the protein and lipid together in the presence of either octylglucoside (octyl-beta-d-glucopyranoside) or deoxycholate and removing the detergent by dialysis. the resulting preparation consisted of lipid vesicles containing all or most of the added protein. the protein in the vesicles was antigenically active, as demonstrated by specific binding to anti-beta2-micr ... | 1978 | 356051 |
| a comparison of labelled antibody methods for the detection of virus antigens in cell monolayers. | a number of labelled antibody methods have been applied to the detection of semliki forest virus antigens after replication of the virus in monolayers of host cells in multi-wellpolystyrene plates. the importance of several reaction variables has been investigated and the sensitivity of the methods compared for different periods of virus replication. direct assays with radio-labelled antibody (rla) and indirect assays using peroxidase-antiperoxidase complexes (pap) were equally sensitive. direct ... | 1979 | 372444 |
| tumour-necrosis factor from the rabbit. iii. relationship to interferons. | | 1979 | 387059 |
| enzyme immunoassay of specific immunoglobulins to semliki forest virus in infected nude (athymic) mice [proceedings]. | | 1979 | 389699 |
| inactivated venezuelan equine encephalomyelitis virus vaccine complexed with specific antibody: enhanced primary immune response and altered pattern of antibody class elicited. | complexes of formalinized venezuelan equine encephalomyelitis (vee) virus vaccine and specific igg formed at antigen-antibody equivalence enhanced the immune responses of rhesus monkeys (macaca mulatta). the predomonant class of antibody elicited by complexes was igg. in contrast, lower titers of antibody and a more biphasic (igg-igm) response were observed after exposure of monkeys to the vaccine alone. in comparison to the response of monkeys primed with antigen, a more rapid secondary respons ... | 1977 | 404363 |
| sensitivity of various human lymphoblastoid cells to the antiviral and anticellular activity of human leukocyte interferon. | of eight lymphoblastoid cell lines studied five were insensitive to both the anticellular and antiviral activities of human leukocyte interferon, and two were sensitive to both activities. one line could not be fully evaluated since it was not possible to study its sensitivity to the antiviral activity. | 1977 | 407887 |
| biological characteristics of a stimulatory factor for viral replication detected in egg fluids. | yolk sac and allantoic fluids and albumen from uninfected chicken eggs contain a low-molecular weight factor which, after 90 minutes of contact with cell cultures, significantly enhances viral replication. of several viruses tested, semliki forest virus exhibited the highest (10(5)-fold) responsiveness to this enhancing factor. maximal enhancement was obtained with cells subjected to low multiplicities of infection. the stimulation of viral replication was linear with the age of the cells in cul ... | 1978 | 415702 |
| delayed-type hypersensitivity against semliki forest virus in mice. | after intracutaneous immunization with purified inactivated semliki forest virus, a delayed-type hypersensitivity without detectable antibodies in serum was obtained in balb/c mice. low doses of antigen given intraperitoneally induced antibodies. intracutaneous immunization with much higher doses induced no specific antibodies, but a footpad swelling was observed after challenge with homolgous antigen. pretreatment with cyclophosphamide before immunization enhanced footpad swelling. microscopic ... | 1979 | 422238 |
| semliki forest virus: cause of a fatal case of human encephalitis. | a fatal case of human encephalitis has been observed for which our results indicate that semliki forest virus (sfv) was the etiologic agent. this is surprising in view of the fact that this virus, which has been widely studied, was believed to be one of the arboviruses nonpathogenic for man. described are the clinical course, the virological examinations performed, and the histopathological findings in the central nervous system. | 1979 | 424742 |
| brain viral persistence and myelin damage in nude mice. | multiple foci of secondary demyelination were observed in the cerebellum of nude mice given two inoculations of avirulent semliki forest virus compared to single lesions seen in similarly treated swiss a2g mice. the increased number of demyelinative plaques were attributed to brain viral persistence for 35 days in the nude mice with correspondingly low serum antibody titres. no neurological signs were observed in any of the mice. | 1979 | 427638 |
| structure and assembly of the semliki forest virus memebrane. | | 1979 | 428635 |
| togavirus interference in culex annulirostris mosquitoes. | culex annulirostris mosquitoes infected with sfv-s, a temperature-sensitive, small-plaque mutant of semliki forest virus isolated from cultured aedes albopictus cells, could not be infected later with wild-type virus (sfv-w). interference occurred as soon as 24 h after infection with sfv-s. in mosquitoes infected with a mixture of the two viruses, both replicated normally. | 1979 | 430033 |
| mitochondrial calcium uptake during infection of chicken embryo cells with semliki forest virus. | the key role of the mitochondria in the regulation of cellular ca2+ led to a study of mitochondrial ca2+ uptake during the infection of chicken embryo cells with semliki forest virus. mitochondrial ca2+ uptake was stimulated during the first 5 h of infection but declined later in infection. the early stimulation suggests an increase of cytoplasmic ionized ca2+, whereas the later decrease indicates mitochondrial injury. this functional deterioration was correlated with an increase of the permeabi ... | 1979 | 430590 |
| altered or increased transfer-rna methylation in the course of interferon action on cells in culture? | the induction of the antiviral state by interferon might reflect the decrease of the rate of biosynthesis, the degradation or the alteration of one or several trnas. this could result in rate-limiting concentrations for codons common in viral rna but rare in host mrna. altered methylation of trna could be the basis of such a phenomenon. however, we could not find an altered extent of methylation of total trna or an altered pattern of methylation, if mixed trnas were chromatographed on mak- or bd ... | 1979 | 446645 |
| two small virus-specific polypeptides are produced during infection with sindbis virus. | we have identified and characterized two small virus-specific polypeptides which are produced during infection of cells with sindbis virus, but which are not incorporated into the mature virion. the larger of these is a glycoprotein with an approximate molecular weight of 9,800 and is found predominantly in the medium of infected cells. three independent lines of evidence demonstrate conclusively that this 9,800-dalton glycoprotein is produced during the proteolytic conversion of the precursor p ... | 1979 | 448798 |
| resistance of aged cells to virus replication. | | 1979 | 456441 |
| studies on the morphology of alphaviruses. | | 1979 | 462801 |