| [assays of cytotoxicity and antiviral activity of crude and semipurified extracts of green leaves of melia azedarach l]. | crude extracts from fresh green leaves of melia azedarach l contain an antiviral factor (fav) able to inhibit the replication of several animal viruses, e.g. polio, vsv, hsv, fmdv, sindbis, junín, pichinde and tacaribe in vero or bhk-21 cells. crude preparations were subjected to different steps of purification like chromatography on sephadex g-100 and deae-sephadex. the antiviral activity of g-100 and deae fractions was fully conserved, whereas contaminating proteins were lost. two types of cyt ... | 1985 | 2825236 |
| elimination of viruses (human immunodeficiency, hepatitis b, vesicular stomatitis and sindbis viruses) from an intravenous immunoglobulin preparation. | more than 10(4) plaque-forming units (pfu)/ml of hiv are inactivated during the alcohol fractionation step from plasma to fraction (fr)-ii+iii, greater than 10(4) pfu/ml is inactivated from fr-ii+iii to fr-ii and greater than 10(4) pfu/ml is inactivated during the polyethylene glycol (peg) fractionation process from fr-ii+iii to intravenous igg (ivig). the total inactivation rate from plasma to ivig via fr-ii+iii or fr-ii was calculated to be greater than 10(8) or 10(12), respectively. the peg f ... | 1987 | 2825431 |
| induction of the stress response: alterations in membrane-associated transport systems and protein modification in heat shocked or sindbis virus-infected cells. | heat shock or sindbis virus infection of chick embryo (ce) or baby hamster kidney (bhk) cells resulted in a decrease in the uptake of 86rubidium+, a k+ tracer. both stressful treatments decreased 86rb+ uptake by inhibition of the ouabain-sensitive na+/k+ atpase. alterations in the intracellular levels of monovalent ions may be involved in translational or transcriptional control of the stress response. heat shock or sindbis virus infection also resulted in an increase in rate of uptake of [3h]de ... | 1987 | 2825445 |
| inactivation of 12 viruses by heating steps applied during manufacture of a hepatitis b vaccine. | the efficacy of two heating cycles (90 sec at 103 degrees c and 10 hr at 65 degrees c) used during manufacture of a plasma-derived hepatitis-b vaccine was validated for the inactivation of 12 virus families. a period of 15 min warming up to 65 degrees c had already completely inactivated representatives of nine virus families, ie, poxvirus (vaccinia), picornavirus (encephalomyocarditis virus), togavirus (sindbis virus), coronavirus (mouse hepatitis virus), orthomyxovirus (influenza virus), rhabd ... | 1987 | 2828525 |
| inactivation of lipid-enveloped viruses in labile blood derivatives by unsaturated fatty acids. | virus sterilization of blood plasma derivatives by addition of several naturally occurring fatty acids was evaluated using vesicular stomatitis virus and sindbis virus as markers for lipid-enveloped virus inactivation and human immunodeficiency virus (hiv). inactivation of greater than or equal to 10(4) tissue culture infectious doses (tcid50) of marker viruses added to antihemophilic factor (ahf) concentrates, with 60-100% retention of ahf activity, was achieved with oleic, 11-eicosenoic, linol ... | 1988 | 2831669 |
| effect of interferon on vero cells persistently infected with sendai virus compared to vero cells persistently infected with sspe virus. | persistent infections with sendai and sspe virus were established in vero cells. sequential passages of these cells were monitored by immunofluorescence and for their sensitivity to the antiviral and antiproliferative effects of interferon (ifn). the cells rapidly developed resistance to the antiviral effect of ifn as judged by the inability of ifn to inhibit the replication of exogenous sindbis virus. this decrease was accompanied by a reduction in the induction of the 2'-5' oligo a synthetase. ... | 1988 | 2831857 |
| absence of antiviral activity in recombinant b cell stimulatory factor 2 (bsf-2). | recombinant b cell stimulatory factor 2 (rbsf-2) did not display any detectable level of antiviral activity when using human diploid fibroblasts, dip-2, fs-4, fs-7, amnion-derived wish and fl cells with vesicular stomatitis virus (vsv) and sindbis virus as challenging agents (less than 2.5 x 10(2) iu/mg). furthermore anti-ifn-beta could not neutralize the immunoglobulin-inducing activity of bsf-2. moreover anti-bsf-2 could not neutralize the antiviral activity of ifn-beta. the data indicate that ... | 1988 | 2832321 |
| genome sequences of a mouse-avirulent and a mouse-virulent strain of ross river virus. | the nucleotide sequence of the genomic rna of a mouse-avirulent strain of ross river virus, rrv nb5092 (isolated in 1969), has been determined and the corresponding sequence for the prototype mouse-virulent strain, rrv t48 (isolated in 1959), has been completed. the rrv nb5092 genome is approximately 11,674 nucleotides in length, compared with 11,853 nucleotides for rrv t48. rrv nb5092 and rrv t48 have the same genome organization. for both viruses an untranslated region of 80 nucleotides at the ... | 1988 | 2833022 |
| reevaluation of the western equine encephalitis antigenic complex of alphaviruses (family togaviridae) as determined by neutralization tests. | fourteen viruses closely related to the fleming strain of western equine encephalitis (wee) virus were cross-tested by serum dilution-plaque reduction neutralization. the results demonstrate that strains mcmillan, r-43738, ag80-646, bear 102091, and y62-33 are subtypes or varieties of western equine encephalitis virus strain fleming. ockelbo, kyzylagach, and babanki are subtypes of the prototype strain (egar 339) of sindbis virus. fort morgan and buggy creek viruses are closely related to each o ... | 1988 | 2833129 |
| nonstructural proteins nsp3 and nsp4 of ross river and o'nyong-nyong viruses: sequence and comparison with those of other alphaviruses. | we have sequenced the nsp3 and nsp4 region of two alphaviruses, ross river virus and o'nyong-nyong virus, in order to examine these viruses for the presence or absence of an opal termination codon present between nsp3 and nsp4 in many alphaviruses. we found that ross river virus possesses an in-phase opal termination codon between nsp3 and nsp4, whereas in o'nyong-nyong virus this termination codon is replaced by an arginine codon. previous studies have shown that two other alphaviruses, sindbis ... | 1988 | 2834873 |
| molecular analysis of sindbis virus pathogenesis in neonatal mice by using virus recombinants constructed in vitro. | genetic loci affecting sindbis virus pathogenesis in neonatal mice have been examined by using a full-length cdna clone of the virus (toto1101). the full-length cdna is linked to a bacteriophage sp6 promoter to facilitate the synthesis of infectious rna transcripts in vitro. virus derived from toto1101 showed reduced virulence (attenuation) in neonatal mice. replacement of the e1 glycoprotein and 6k genes of toto1101 with cloned e1 and 6k genes derived from a virulent sindbis virus strain, ar339 ... | 1988 | 2835514 |
| viral neurovirulence. | | 1988 | 2835547 |
| polyamine depletion of cells reduces the infectivity of herpes simplex virus but not the infectivity of sindbis virus. | the effect of polyamines on the viral growth was examined using cell strains that could be effectively depleted of polyamines. in order to avoid the polyamines present in serum we used a polyamine auxotrophic chinese hamster ovary cell line p22 growing in serum-free medium and vero cells growing in low serum medium. the final yield of an enveloped rna virus, sindbis, in p22 cells was not decreased by depletion of cellular polyamines although the onset of the viral replication was delayed. in con ... | 1988 | 2835567 |
| molecular basis of sindbis virus neurovirulence in mice. | we examined a variety of strains of sindbis virus for the genetic changes responsible for differences in neurovirulence in mice. sv1a (a low passage of the ar339 strain of sindbis virus), a neuroadapted sindbis virus (nsv), and two laboratory strains of sindbis virus (hrsp and toto1101) were examined. nsv causes severe encephalomyelitis with hind-limb paralysis and high mortality after intracerebral inoculation in weanling mice. in contrast, sv1a causes only mild, nonfatal disease in weanling mi ... | 1988 | 2836615 |
| alpha-(-)-peltatin, an antiviral constituent of amanoa aff. oblongifolia. | | 1988 | 2836661 |
| antiviral activity of uridine 5'-diphosphate glucose analogues against some enveloped viruses in cell culture. | twenty five analogues of uridine 5'-diphosphate glucose were screened against herpes simplex type 2, vaccinia virus, sindbis virus and african swine fever virus. after screening, the compound 5'-[[[[(2",3",4",6"-tetra-o-benzoyl-alpha-d- glucopyranosyl)oxi]carbonyl]amino]sulfonyl]uridine (2), the synthesis of which has been reported (camarasa et al., j. med. chem. 28, 40-46, 1985), was selected for further study. this compound showed in vitro activity against all viruses tested. the replication o ... | 1987 | 2837144 |
| sindbis virus infection decreases intracellular ph: alkaline medium inhibits processing of sindbis virus polyproteins. | infection of baby hamster kidney cells by sindbis virus, an alphavirus, resulted in a decrease in the intracellular ph of approximately 0.5 units within the first 1-2 hr after infection as measured either by equilibrium labeling with [14c]benzoic acid or by use of a ph-sensitive fluorescent probe, 2,7-bis-carboxyethyl-5,6-carboxyfluorescein-acetooxymethyl ester. in contrast, intralysosomal ph, as measured using an endocytized ph-sensitive probe, fluorescein isothiocyanate-labeled dextran, was no ... | 1988 | 2842937 |
| virus removal or inactivation in hemoglobin solutions by ultrafiltration or detergent/solvent treatment. | two procedures to eliminate virus infectivity from hemoglobin solutions at ambient temperature were evaluated. in the first, virus removal was assessed during the ultrafiltration of hemoglobin solutions through a membrane with a nominal molecular weight cut-off of 100,000 daltons. the results of this study demonstrated that less than 0.1% of any virus originally spiked into the solution was detectable in the ultrafiltrate. in the second procedure the inactivation of viruses in hemoglobin solutio ... | 1988 | 2846096 |
| virus inactivation in hemoglobin solutions by heat. | to determine the feasibility of heat treating hemoglobin solutions to inactivate viruses, we performed experiments on the thermal stability of this protein and found that the structure and function of deoxyhemoglobin are well preserved during incubation at 60 degrees c for 10 hours at a ph of 7.5. model viruses and the human immunodeficiency virus were rapidly inactivated under these conditions. the results imply that incubation at 60 degrees c is a practical method for inactivating viruses in h ... | 1988 | 2846097 |
| replication of the genome of alphaviruses. | the genome of semliki forest virus (sfv) is 11,442 nucleotides with a 5' cap-structure and a 3' poly(a) tail of about 100 residues. the genome of the closely relate sindbis virus (sin) is slightly longer (11,703 nucleotides). the parental rna is first translated from the 5' two thirds to yield; nsp1, nsp2, nsp3 and nsp4, which are cleaved from a polyprotein of 2431 amino acids (sfv). the parental genome is copied to a full-length minus strand with poly(u) at the 5' end. the minus strand is used ... | 1987 | 2846593 |
| identity of karelian fever and ockelbo viruses determined by serum dilution-plaque reduction neutralization tests and oligonucleotide mapping. | the causative agents of ockelbo disease in sweden, pogosta disease in finland, and karelian fever in the ussr have been attributed to alphaviruses (family togaviridae) related to sindbis virus. we compared prototypes sindbis, ockelbo, and karelian fever viruses by neutralization tests. we also analyzed oligonucleotide fingerprint maps of prototypes ockelbo and karelian fever viruses and a strain of sindbis virus from czechoslovakia. the results indicate that ockelbo and karelian fever viruses ar ... | 1988 | 2849885 |
| characterization of b cells and ia expression in sindbis virus encephalitis. | | 1988 | 2849900 |
| interaction of alphaviruses with the serum complement system is a function of method of purification. | the interaction of sindbis and ross river viruses with the serum complement system in vitro was influenced by the type of density gradient used to purify them. sindbis virus purified on sucrose gradients activated the alternate serum complement pathway while ross river virus prepared in an identical manner had no effect on c3 turnover in non-immune serum. both viruses purified on tartrate gradients inhibited the spontaneous cleavage of c3 in normal serum. at least some of this inhibition appeare ... | 1988 | 2850782 |
| culex theileri and sindbis virus; salivary glands infection in relation to transmission. | | 1985 | 2852707 |
| [changes in cellular microfilaments in viral infection]. | the effect of disorders in actin microfilament polymerization by cytochalasin b (cb) on the development of cytopathic changes was studied in two models. cb in concentrations of 0.1-1.0 microgram/ml enhanced 3-5-fold the formation of symplasts in a line of kidney cells from green monkey 4647 infected with carnivore distemper virus and inhibited this process in higher concentrations (2.5-5.0 micrograms/ml). the addition of cb in concentrations 5-10 micrograms/ml into the medium of a line of chines ... | 1988 | 2854678 |
| overwintering of culex mosquitoes in sweden and their potential as reservoirs of human pathogens. | 1. culex pipiens l. and cx torrentium martini are suspected enzootic vectors in sweden of sindbis virus causing ockelbo disease in man. to estimate their potential as virus reservoirs over the winter, mosquitoes were collected from august to may from a cellar in a rural area, central sweden. the mosquitoes were dissected and examined for blood content, gonotrophic stage, parity and insemination, and tested for fructose. 2. cx pipiens, cx torrentium and cx territans walker constituted 94% of 887 ... | 1987 | 2856507 |
| sindbis virus isolations from saudi arabian mosquitoes. | a study in late 1979 to early 1980 was conducted to assess arbovirus activity in the eastern province of saudi arabia. from 38,245 mosquitoes collected at 3 locations, 16 isolations of sindbis virus were made: 13 from culex univittatus and one each from cx tritaeniorhynchus, cx pipiens complex, and culex spp. these isolations represent the first records of a mosquito-borne virus from the gulf of arabia and implicate cx univittatus as the principal vector. a potential risk of human diseases exist ... | 1985 | 2859676 |
| inhibition by norakin (triperiden) of sindbis virus infection in mice. | intranasal (i. n.) infection with 10 ld50 of sindbis virus caused acute encephalomyelitis and death in abd2f1 mice 3-7 days post infection (p.i.). histologic lesions were found in the cns, pancreas. liver, parotid glands, exorbital lacrimal glands, lymphoid organs and kidneys. repeated oral administration of the anticholinergic anti-parkinson drug norakin protected infected animals from death in a dose-dependent manner when treatment was started prior to but not after virus inoculation. the maxi ... | 1985 | 2864821 |
| failure of high doses of potentially antiviral agents to prevent death in virus-infected mice. | the influence of increasing doses of various potentially antiviral agents on mengo virus-and sindbis virus-infected mice was assessed determining death rates and histologic lesions. all drugs given in abundance showed dose-dependent decrease of antiviral activity following the maximum protective effects in either animal model. from the toxicological point of view the antiviral agents in question could be classified into two groups. high doses of tilorone hydrochloride or 10-carboxymethyl-9-acrid ... | 1985 | 2864822 |
| ockelbo disease: arthralgia 3-4 years after infection with a sindbis virus related agent. | | 1986 | 2871323 |
| isolation of viruses from mosquitoes of the negev, israel. | in a survey of the mosquito population of the negev carried out between july 1982 and september 1984, over 85,000 insects belonging to 10 species were tested for the presence of viruses. they yielded 91 virus isolates in c-6/36 mosquito cell cultures; 20 of the isolates were recovered also in vero cell cultures and in suckling mice inoculated intracerebrally. of the 20 isolates recovered in the vertebrate systems 17 were identified as sindbis, and three as west nile viruses. 71 viruses which hav ... | 1986 | 2879372 |
| approaches to the study of vector specificity for arboviruses--model systems using cultured mosquito cells. | | 1987 | 2884833 |
| use of enzyme immunoassay and nucleic acid hybridization for detecting sindbis virus in infected mosquitoes. | aedes aegypti mosquitoes were inoculated intrathoracically with prototype sindbis virus, held at 26.7 degrees c for from 0-95 h and placed at -70 degrees c. individual mosquitoes were tested for virus by plaque assay in vero cells, for viral rna by nucleic acid hybridization using a cloned cdna probe, and for viral protein by enzyme-linked immunosorbent assay. virus was detected by plaque assay as early as 8 h after infection. sindbis virus rna was detected by nucleic acid hybridization 18 h aft ... | 1987 | 2890652 |
| [ecology of mosquito-borne infections in fennoscandia--a review]. | | 1988 | 2898578 |
| alphavirus rna replicase is located on the cytoplasmic surface of endosomes and lysosomes. | using morphological and cell biological techniques, we have shown that the rna replicase of semliki forest and sindbis virus (two closely related alphaviruses) is located in complex ribonucleoprotein structures associated with the cytoplasmic surface of modified secondary lysosomes and endosomes. these nucleoprotein complexes often form a bridge between the membrane of the endocytic vacuole and the rough endoplasmic reticulum where the synthesis of the structural proteins of these viruses occurs ... | 1988 | 2904446 |
| seasonal activity of mosquitoes in an ockelbo disease endemic area in central sweden. | in the sässman area, province of hälsingland, sweden, mosquitoes were sampled in 1983 from aquatic habitats, overwintering sites, cattle sheds, human bait, with uv-light traps, rabbit-, guinea-pig-, hen-, dove- and unbaited suction traps and similarly baited net traps. anopheles beklemishevi, an. messeae, aedes cantans, ae. cataphylla, ae. cinereus, ae. communis, ae. diantaeus, ae. excrucians, ae. hexodontus, ae. intrudens, ae. leucomelas, ae. pionips, ae. punctor, ae. vexans, culex pipiens, cx. ... | 1986 | 2906960 |
| diel activity patterns of blood-seeking anthropophilic mosquitoes in central sweden. | 1. blood-seeking diel activity cycles of mosquitoes are described from 24 h landing catches on human bait in a field and a forest habitat during june-august in central sweden. 2. daytime activity in the field was low or absent, whilst in the forest activity was relatively even throughout the diel. 3. in both habitats, activity peaks generally occurred about sunset and sunrise and were more distinct in the field than in the forest. 4. data from this and other studies show that, in general, aedes ... | 1988 | 2908783 |
| form-determining functions in sindbis virus nucleocapsids: nucleosomelike organization of the nucleocapsid. | purified intact sindbis virus nucleocapsids were treated at different ph values or with various concentrations of divalent cations, cation chelators, salt, or formamide. the resulting structures were examined by velocity sedimentation, electron microscopy, and protein-protein cross-linking. changes in each of the test conditions led to alterations in the sedimentation profile of treated nucleocapsids. appropriate concentrations of formamide or divalent cations generated beaded strandlike structu ... | 1989 | 2911124 |
| effect of sindbis virus infection on induction of heat shock proteins in aedes albopictus cells. | when aedes albopictus cells (clone c7) were infected with sindbis virus, the production of cytopathic effect cpe depended largely on the conditions under which the cells were cultured. we observed marked inhibition of cellular rna and protein synthesis, as well as a loss of the ability to induce heat shock proteins, e.g., hsp70, under conditions which led to cytopathic effect. infected cells in which heat shock proteins could no longer be induced contained much lower amounts of hsp70 mrna after ... | 1989 | 2911128 |
| sindbis virus: an efficient, broad host range vector for gene expression in animal cells. | sindbis virus, an enveloped virus with a single-stranded rna genome, was engineered to express a bacterial protein, chloramphenicol acetyltransferase (cat), in cultured insect, avian, and mammalian cells. the vectors were self-replicating and gene expression was efficient and rapid; up to 10(8) cat polypeptides were produced per infected cell in 16 to 20 hours. cat expression could be made temperature-sensitive by means of a derivative that incorporated a temperature-sensitive mutation in viral ... | 1989 | 2922607 |
| sindbis virus mutations which coordinately affect glycoprotein processing, penetration, and virulence in mice. | rapid penetration of baby hamster kidney cells was used as a selective pressure for the isolation of pathogenesis mutants of the s.a.ar86 strain of sindbis virus. unlike most sindbis virus strains, s.a.ar86 is virulent in adult as well as neonatal mice. two classes of mutants were defined. one class was attenuated in adult mice inoculated intracerebrally as well as in neonatal mice inoculated either intracerebrally or subcutaneously. sequence analysis of the glycoprotein genes of the parent viru ... | 1989 | 2926866 |
| [studies on the combined treatment with cyclophosphamide and virus in mice transplanted with s180 ascitic tumor cells]. | | 1985 | 2938760 |
| [preliminary studies on the efficacy of treating twice with different virus strains for s180 ascitic mice]. | | 1985 | 2939992 |
| glucose trimming and mannose trimming affect different phases of the maturation of sindbis virus in infected bhk cells. | the roles of glucose and mannose trimming in the maturation of sindbis virus in bhk cells have been investigated using inhibitors of glycoprotein oligosaccharide processing. in the presence of the glucosidase inhibitor n-methyl-1-deoxynojirimycin the viral glycoproteins were equipped with oligosaccharides of the composition glc3man8,9(glcnac)2 and the yield of virus in the extracellular medium was reduced as a result of a block in the proteolytic cleavage of the precursor (pe2) of the e2 viral e ... | 1987 | 2960074 |
| human gamma interferon induction by staphylococcal protein a: effector cells, kinetics and the effect of prostaglandin, indomethacin, ibuprofen and aspirin. | soluble staphylococcal protein a (spa) induces the synthesis of gamma-interferon (gamma-ifn) by human peripheral blood lymphocytes (pbl). to investigate the kinetics of this gamma-ifn induction and the effector cells involved, we used a highly purified spa preparation, pbl from healthy volunteers, and a cpe-inhibition gamma-ifn assay with sindbis virus in human fibroblasts. the production of spa-induced gamma-ifn (spa-gamma-ifn) peaked 48 h after the addition of spa to cultures of pbl and decrea ... | 1988 | 2966775 |
| differential expression of surface proteins, virus receptors and histocompatibility antigens in sv40-transformed human choroid cells and their clones. | human choroid (hc) cells transformed by simian virus 40 (hc/sv40) and some of their soft agar-derived clones were utilized to study the influence of sv40 transformation on the expression of some differentiation parameters. the presence of receptors for dna and rna viruses, known to induce cytopathic effects in target cells, always occurred in normal hf and hc/sv40 cells as well as in their derived clones, whereas differences were observed in the expression of influenza a and sindbis virus recept ... | 1985 | 2983079 |
| morphological and functional polarity of an epithelial thyroid cell line. | the thyroid epithelial cell line frt in monolayer culture appeared to be strongly polarized by morphological criteria. cells were connected by tight junctions, exposed microvilli toward the culture medium and formed domes at confluency. frt cells were infected with vesicular stomatitis virus (vsv) and sindbis virus and the budding polarity was examined 8 and 16 h after infection, respectively. vsv budding occurred preferentially from the basolateral domain of plasma membrane, while sindbis virus ... | 1985 | 2992984 |
| hazelhurst-vesicular-stomatitis-virus g and sindbis-virus e1 glycoproteins undergo similar host-cell-dependent variation in oligosaccharide processing. | we have examined and compared the host-cell-dependent glycosylation of the g glycoprotein of vesicular-stomatitis virus (hazelhurst strain) and the e1 and e2 glycoproteins of sindbis virus replicated by baby-hamster kidney, chicken-embryo fibroblast and mouse l929 monolayer cell cultures. the results of endo-beta-n-acetylglucosaminidase h digestion of viral proteins labelled with [3h]mannose or leucine and pronase-digested glycopeptides labelled with [3h]mannose indicated that both the g protein ... | 1985 | 2994631 |
| [isolation of the causative agent of karelian fever from aedes sp. mosquitoes]. | the results of isolation of an alphavirus strain from aedes sp. mosquitoes collected in the focus of karelian fever are presented. according to the results of serological studies, the isolated strain leiv-9298 karelia belongs to the antigenic complex sindbis-western equine encephalomyelitis. the appurtenance of the isolated agent to the alphavirus genus has been confirmed by electron microscopic examinations. a rise of antibody titres to leiv-9298 karelia virus in paired sera of subjects with a ... | 1985 | 2996238 |
| effect of tunicamycin on the development of the cytopathic effect in sindbis virus-infected avian fibroblasts. | in sindbis virus-infected avian cells the development of the cytopathic effect is correlated with the disruption of plasma membrane function. sindbis virus inhibits the activity of the na+k+atpase, a membrane-associated enzyme complex which regulates intracellular monovalent cation levels. tunicamycin, which blocks envelope protein glycosylation, prevents inhibition of na+k+atpase activity and the development of morphological changes in sindbis virus-infected cells. although inhibition of na+k+a ... | 1985 | 2998024 |
| [blocking of sindbis virus replication in the body of infected mice using an inhibitor of chymotrypsin-like proteases]. | parenteral administration of an inhibitor of chymotrypsin-like proteases (tpck) to mice infected with alphavirus (sindbis ar/339 strain) blocked virus replication in the brain and inhibited the development of viremia in the infected animals. the most likely mechanism of tpck antiviral effect seems to consist in disturbance of proteolytic processing of viral proteins. | 1985 | 2998094 |
| susceptibility of different leukemic cell lines to the anticellular and antiviral effects of interferons. | a total of 18 different types of human leukemic cell lines were tested for their susceptibility to the anticellular and antiviral effects of interferons (ifns) alpha, beta and gamma. in general, only the three myelogenous leukemic cell lines u937, kg-1 and hl-60 were found to be highly susceptible to the anticellular effect of the different ifns while cells of the other lineages were relatively resistant. in order to determine whether the cell lines were sensitive to the antiviral effects of ifn ... | 1985 | 2999858 |
| antiviral effect of 1-morpholinomethyl-tetrahydro-2(1h)-pyrimidinone (dd-13) in experimental alphaviral infections in white mice. | 1-morpholinomethyl-tetrahydro-2(1h)-pyrimidinone (dd-13), a selective inhibitor of the alphaviral reproduction in vitro, manifests a pronounced antiviral activity in experimental infections with semliki forest virus (sfv) and sindbis virus in white mice (intraperitoneally inoculated with 10-10 000 ld50). introduced subcutaneously in mice infected with sfv the compound was effective within the dose range of 4.7-300 mg/kg. the effective dose (ed)50 value of dd-13 is about 18.7 mg/kg and the maximu ... | 1985 | 3000394 |
| differential effects of photoactive furanyl compounds on virus functions. | | 1985 | 3003768 |
| [ultrastructural changes of neonatal thymuses of mice infected with virus]. | | 1985 | 3004756 |
| rna virus genomes hybridize to cellular rrnas and to each other. | in this communication we show that the rna genomes of vesicular stomatitis, sindbis, and reoviruses can specifically hybridize under stringent conditions to the large rrnas present in hela cell cytoplasmic extracts. in addition, we show that some virus genome rnas can also hybridize to each other. on the basis of our previous detailed studies identifying specific regions of hybridization between the poliovirus genome and 28s rrna, we suggest that a similar phenomenon of "patchy complementary" ma ... | 1986 | 3005635 |
| antiviral effect of harmine, a photoactive beta-carboline alkaloid. | | 1986 | 3006095 |
| sindbis virus mutant ts20 of complementation group e contains a lesion in glycoprotein e2. | a technique has been devised to readily obtain the entire structural protein region of sindbis virus cloned into a plasmid vector. this method uses the fact that the nearest site for restriction enzyme hindiii to the 3' terminal poly(a) occurs at nucleotides 6266-6271 in the genomic rna. inserts extending from the poly(a) tract to this hindiii site are 5438 nucleotides long (excluding the poly a tract) and contain the entire 4106-nucleotide structural protein region. using an oligo(dt)-tailed ve ... | 1986 | 3008426 |
| complex-specific immunoglobulin m antibody patterns in humans infected with alphaviruses. | sera from humans with serologically confirmed eastern equine encephalitis, western equine encephalitis, pogosta (ockelbo), mayaro, ross river, and chikungunya virus infections were tested by immunoglobulin m (igm) antibody capture enzyme immunoassay. diagnostically useful igm antibody titers were detected, and selected sera with high igm antibody titers were tested for igm antibody with nine heterologous alphaviruses. the results provide evidence for the complex specificity of igm antibody and i ... | 1986 | 3009526 |
| regulated expression of sindbis and vesicular stomatitis virus glycoproteins in saccharomyces cerevisiae. | cdnas encoding either the structural proteins (capsid and glycoproteins e1 and e2) of sindbis virus or the glycoprotein of vesicular stomatitis virus (vsv) were fused to the saccharomyces cerevisiae galactokinase gene (gal1) promoter and inserted into a yeast shuttle vector. after addition of galactose to yeast transformed with this vector, 2.5-3% of total yeast protein synthesis was detected as virus proteins by specific anti-virus protein antibodies. in cells containing the sindbis virus struc ... | 1986 | 3012523 |
| scanning fluorescence correlation spectroscopy. ii. application to virus glycoprotein aggregation. | scanning fluorescence correlation spectroscopy is a new approach to measuring changes in the state of aggregation of cell membrane proteins. measurements of the mean number of aggregates of virus glycoproteins from sindbis virus and vesicular stomatitis virus agree with the findings of a recent fluorescence photobleaching recovery study on the same systems (johnson, d.c., m.j. schlesinger, and e.l. elson, 1981, cell, 23:423-431). sindbis virus glycoproteins are immobilized and cannot be induced ... | 1986 | 3013328 |
| sindbis and west nile virus infections in the witwatersrand-pretoria region. | from mid-december 1983 until mid-april 1984, there was an epidemic of sindbis (sin) virus infection in the witwatersrand-pretoria region in which hundreds of human cases were diagnosed clinically. twenty-eight of these diagnoses were confirmed in the laboratory by seroconversion as being infections with sin virus, and 5 cases of infection with west nile (wn) virus were also found. attempts to isolate virus from 66 patients, mainly from serum specimens, were unsuccessful. infection rates for the ... | 1986 | 3016922 |
| expression of genes encoding vesicular stomatitis and sindbis virus glycoproteins in yeast leads to formation of disulfide-linked oligomers. | saccharomyces cerevisiae strains transformed with plasmids containing cdnas coding for the glycoproteins of vesicular stomatitis or sindbis viruses can be induced to produce large amounts of glycosylated virus glycoproteins. studies reported here show that these proteins from high molecular weight disulfide-linked oligomers in the yeast endoplasmic reticulum. oligomers were also found for two genetically altered forms of vsv g; one of these was lacking the membrane anchor domain and the other ha ... | 1986 | 3016985 |
| experimental assessment of the vector competence of culex (culex) neavei theobald with west nile and sindbis viruses in south africa. | culex univittatus is the maintenance vector of west nile (wn) and sindbis (sin) viruses on the inland plateau of south africa and also transfers infection to man. both viruses have frequently been isolated from this mosquito and human immunity is high on the plateau. in the natal lowlands where cx univittatus is replaced by cx neavei, apparently the main vector there, immune rates are low and few isolations have been made from this species. vector competence experiments were carried out with cx ... | 1986 | 3024364 |
| sindbis virus infection increases hexose transport in quiescent cells. | sindbis virus infection of baby hamster kidney cells or chick embryo cells resulted in a significant increase in the rate of uptake of [2-3h]deoxy-d-glucose ([3h]dglu). stimulation of hexose transport in sindbis virus-infected cells occurred only if the cells were rendered quiescent by culturing at high density or by serum starvation. in contrast, sindbis virus-induced inhibition of potassium transport, measured as a decrease in the uptake of 86rb+, was independent of cell growth state. stimulat ... | 1986 | 3024395 |
| passive protection across subgroups of alphaviruses by hyperimmune non-cross-neutralizing anti-sindbis serum. | extended hyperimmunization of rabbits with sindbis (sin) or semliki forest (sf) viruses causes the production of antisera that are cross-reactive with virus-infected cells in antibody-dependent, complement-mediated cytotoxicity assays but that do not cross-neutralize viruses in vitro. c3h/hej mice given gamma globulin fractionated from the extended hyperimmune antiserum against sin, but not control sera, were protected from challenge by 100 ld50 of sf, a virus which is in a different subgroup th ... | 1987 | 3025890 |
| elevated serum immune complex levels in pogosta disease, an acute alphavirus infection with rash and arthritis. | circulating immune complexes (cic) were studied in pogosta disease, an acute alphavirus infection with fever, rash and arthritis. the disease is caused by a virus antigenically closely related to sindbis virus. 75 serum specimens from 25 patients with serologically verified infection were obtained from 1-87 days after the onset. six different cic detection methods were used and cics were observed in all patients at least with one test. tests based on cic binding onto human platelets followed the ... | 1986 | 3029375 |
| synergistic anticellular and antiviral activities of human recombinant interferon-gamma and -beta. | the synergism of anticellular and antiviral activities of recombinant human interferon-gamma (reifn-gamma) and recombinant human interferon-beta (reifn-beta) was examined in vitro using human melanoma sk-mel-28 cells. some differences were detected in the kinetics of anticellular activity between both ifns, namely the inhibitory effect of reifn-beta occurred earlier than that of reifn-gamma. significant synergism was detected in the anticellular activity of both ifns when growth curves and isobo ... | 1986 | 3031263 |
| primary structure of poliovirus defective-interfering particle genomes and possible generation mechanisms of the particles. | the genomes of defective-interfering (di) particles derived from the sabin strain of type 1 poliovirus (pv1(sab] were characterized by nuclease s1 mapping using complementary dna (cdna) copies of pv1(sab) genome as probes. the results demonstrated variety in the size and location of the deletions, which were compatible with our previous prediction. the results further indicated that the locations of the deletions were limited within the internal genome region encoding viral capsid proteins and t ... | 1986 | 3031313 |
| the pathogenesis of spinal cord involvement in the encephalomyelitis of mice caused by neuroadapted sindbis virus infection. | weanling mice develop an acute encephalomyelitis with high mortality after intracerebral inoculation of neuroadapted sindbis virus. the mice develop kyphoscoliosis and hindlimb paralysis. immunohistochemical and in situ hybridization studies have demonstrated virus in the gray matter of the brain and spinal cord. ventral horn cells are prominently infected, providing an anatomical basis for the clinical poliomyelitis. a novel route of spread of inoculated virus within the central nervous system ... | 1987 | 3031369 |
| sindbis virus mutants resistant to mycophenolic acid and ribavirin. | previous work from this laboratory has demonstrated a correlation between the inhibition by ribavirin (rbv), mycophenolic acid (mpa), or 2-amino thiadiazole (tda) of sindbis virus replication in aedes albopictus mosquito cells and a reduction in cellular gtp levels. this reduction in gtp results from the inhibition by these drugs of inosine monophosphate dehydrogenase (impdh), the first enzyme specific for the de novo synthesis of gmp. by serial passage of sv in a. albopictus cells in the presen ... | 1987 | 3033882 |
| synergistic action of quercetin and murine alpha/beta interferon in the treatment of mengo virus infection in mice. | abd2f1 mice were infected intraperitoneally (i.p.) or intranasally (i.n.) with mengo or sindbis virus and treated with either crude murine alpha/beta interferon (muifn-alpha/beta) or quercetin, or both. muifn-alpha/beta given i.p. or intramuscularly (i.m.) 1-3 h before the infection had a dose-dependent protective effect regardless of the route of administration. when given after the infection, ifn did not show any effect. oral quercetin, capable of protecting cardio, i.e. mengo virus-infected m ... | 1987 | 3038013 |
| [medical topics: ockelbo disease/myoglobin and myocardial infarction]. | | 1986 | 3039231 |
| different kinetics of antiviral and anticellular activities between human recombinant and natural interferon-gamma arising from different receptor-binding properties. | human recombinant interferon-gamma (reifn-gamma) and human natural interferon-gamma (ifn-gamma) showed significant differences in antiviral and anticellular activities. namely, reifn-gamma exhibited antiviral activity against sindbis virus and anticellular activity against hela s3 cells at significantly lower concentrations as compared with ifn-gamma at short exposure times of between 1 and 4 hr. this difference of activities was explicable in terms of different binding activities of the two ifn ... | 1986 | 3095289 |
| reduction in antiviral activity of human interferon-gamma in acidic media with reference to structural change. | the fluorescence intensity of a unique tryptophan 36 in human interferon-gamma was drastically decreased below ph 4 with a concomitant decrease of antiviral activity. the region of residues 32-42 of human interferon-gamma was found by calculation to have a low hydrophobicity together with a high helical hydrophobic moment, and the net electric charge of this region having an amphiphilic helical structure changed significantly near ph 4. these results suggest that the region of residues 32-42 pla ... | 1987 | 3118958 |
| the effects of inhibitors of glucosidase i on the formation of sindbis virus. | we have examined the effects of deoxynojirimycin and castanospermine, compounds known to inhibit the removal of glucose from high mannose asparagine-linked oligosaccharides, on the formation of sindbis virus. these drugs inhibited virion formation in baby hamster kidney (bhk) cells, 15b - the cho cell line that lacks glcnac transferase activity, and chicken embryo fibroblasts, although our results with the latter cells were variable. we analyzed the [3h]mannose-labeled oligosaccharides from sind ... | 1985 | 3158136 |
| regulation of glycosylation. the influence of protein structure on n-linked oligosaccharide processing. | the sindbis virus glycoproteins, e1 and e2, comprise a useful model system for evaluating the effects of local protein structure on the processing of n-linked oligosaccharides by golgi enzymes. the conversion of oligomannose to n-acetyllactosamine (complex) oligosaccharides is hindered to different extents at the four glycosylation sites, so that the complex/oligomannose ratio decreases in the order e1-asn139 greater than e2-asn196 greater than e1-asn245 greater than e2-asn318. the processing st ... | 1988 | 3198629 |
| sindbis virus neutralization. | | 1988 | 3207286 |
| immunogenicity, pathogenicity, and transmissibility of a recombinant vaccinia virus in calves. | experiments concerned with the immunogenicity, pathogenicity, and transmissibility of a recombinant vaccinia:sindbis virus were conducted. the wr strain of the recombinant vaccinia:sindis virus was found to be infective for calves and mildly pathogenic, resulting in local tissue reaction. it was not transmissible to other calves. also, it was found to be immunogenic when inoculated intradermally into calves, and antibody was produced against the parent vector virus (vaccinia) and the sindbis ant ... | 1988 | 3239835 |
| t cell-mediated cytotoxicity against dengue-infected target cells. | a cytotoxic t lymphocyte (ctl) response to dengue virus-infected target cells is described. effector cells were generated in an in vitro secondary culture and appeared to be t cells possessing both the lyt 1.1 and lyt 2.1 surface antigens. a stronger ctl response was noted with the h-2k haplotype compared to h-2d, and h-2 compatibility was required between ctl and target cells. ctl generated showed some cross-reactivity with target cells infected with japanese encephalitis virus (jev), another f ... | 1988 | 3262810 |
| large-scale production and properties of a solvent-detergent-treated factor ix concentrate from human plasma. | a human solvent-detergent (sd)-treated factor ix concentrate has been produced from cryoprecipitate-poor plasma using deae-sepharose cl-6b and heparin-sepharose cl-6b chromatography. the deae eluate was incubated with an sd mixture [0.3% tri(n-butyl) phosphate-1% tween 80, 6-h at 24 degrees c] which was found to inactivate, in less than 1 h, more than 3.8 log10 of vesicular stomatitis virus and more than 4.8 log10 of sindbis virus; the sd was removed by a subsequent heparin adsorption step. the ... | 1988 | 3265237 |
| [immunofluorescent detection of viral antigens in the enzymatic processing of histological and cytological matter]. | | 1987 | 3314146 |
| effects of 5'-terminal modifications on the biological activity of defective interfering rnas of sindbis virus. | we have been studying defective interfering (di) genomes of the rna enveloped virus sindbis virus. deletion mapping of a di cdna demonstrated that only sequences at the 3' and 5' termini of the genome are required for the di rna to be biologically active. we constructed a series of cdnas that transcribe di rnas differing only in 5'-terminal sequences. two of the 5' termini identical to ones found in naturally occurring di rnas are the 5' terminus of the virion rna (di-549) and the first 142 nucl ... | 1988 | 3334750 |
| processing the nonstructural polyproteins of sindbis virus: study of the kinetics in vivo by using monospecific antibodies. | plasmids were constructed which contained a large portion of each of the four nonstructural genes of sindbis virus fused to the n-terminal two-thirds of the trpe gene of escherichia coli. the large quantity of fusion protein induced from cells containing these plasmids was subsequently used as an antigen to generate polyclonal antisera in rabbits. each antiserum was specific for the corresponding nonstructural protein and allowed ready identification of each nonstructural protein and of precurso ... | 1988 | 3339717 |
| selection for accelerated penetration in cell culture coselects for attenuated mutants of venezuelan equine encephalitis virus. | previous studies with sindbis virus (sb) suggested that a single point mutation in glycoprotein e2 (serine 114 to arginine 114) conferred three phenotypic alterations: attenuation in neonatal mice, accelerated penetration of cultured cells, and efficient neutralization by two e2-specific monoclonal antibodies (davis, fuller, dougherty, olmsted, and johnston (1986) proc. natl. acad. sci. usa 83, 6771-6775). moreover, selection for rapidly penetrating mutants of sb coselected for attenuation in vi ... | 1988 | 3341117 |
| svlm21, a mutant of sindbis virus able to grow in aedes albopictus cells in the absence of methionine, shows increased sensitivity to s-adenosylhomocysteine hydrolase inhibitors such as neplanocin a. | inhibition of s-adenosylhomocysteine (adohcy) hydrolase by compounds such as neplanocin a (npa) leads to the build-up of adohcy and the inhibition of methyltransferase enzymes. whether assayed by efficiency of plaquing or virus yield, svlm21, a mutant of sindbis virus resistant to methionine deprivation, was more sensitive to npa than was the standard virus (svstd) from which it was derived. for example, whereas 10 micrograms npa/ml depressed the yield of svlm21 by more than 30-fold, the yield o ... | 1988 | 3347999 |
| basis of neurovirulence in sindbis virus encephalomyelitis of mice. | neuroadapted sindbis virus (nsv) was selected by serial passage of wild-type sindbis virus (sv) in mouse brain. after intracerebral inoculation of weanling mice, nsv causes a severe encephalomyelitis with hindlimb paralysis and high mortality; sv causes nonfatal mild disease. in order to determine the biologic basis of neurovirulence in vivo, these viral infections have been compared by using infectivity assays, light and electron microscopy, in situ hybridization, immunohistochemistry, and doub ... | 1988 | 3367635 |
| studies on the pharmacological activity of amazonian euphorbiaceae. | plant material from 34 amazonian species of the family euphorbiaceae were collected and extracts prepared. sixteen of these species have a documented use as a medicinal agent. the extracts were tested for their ability to inhibit the growth of the bacteria, escherichia coli and staphylococcus aureus; the yeasts, saccharomyces cerevisiae and candida albicans; the dermatophytic fungi, microsporum canis, microsporum fulvum, microsporum gypseum and trichophyton gallinae; the viruses, sindbis virus a ... | 1988 | 3374150 |
| effect of actinomycin d and cycloheximide on replication of sindbis virus in aedes albopictus (mosquito) cells. | production of sindbis virus in the presence of transcription and translation inhibitors was examined in three aedes albopictus cell lines. addition of cycloheximide to heat-resistant sindbis virus (svhr)-infected mosquito cells arrested viral rna synthesis completely, in contrast to the effects of this drug on virus-infected vertebrate cells. production of mature virus by both svhr (a variant commonly used as a wild-type virus) and sbamr (a mutant which is resistant to the effects of 18 h of pre ... | 1988 | 3392770 |
| western equine encephalitis virus is a recombinant virus. | the alphaviruses are a group of 26 mosquito-borne viruses that cause a variety of human diseases. many of the new world alphaviruses cause encephalitis, whereas the old world viruses more typically cause fever, rash, and arthralgia. the genome is a single-stranded nonsegmented rna molecule of + polarity; it is about 11,700 nucleotides in length. several alphavirus genomes have been sequenced in whole or in part, and these sequences demonstrate that alpha-viruses have descended from a common ance ... | 1988 | 3413072 |
| antibody-mediated activation of sindbis virus. | the biological activity of an anti-sindbis monoclonal antibody (mcab 49) has been explored. the antibody recognizes an epitope on the e2 glycoprotein of sindbis virus and, in the presence of complement (c'), neutralizes virus infectivity. in the absence of c', reaction of the antibody with our laboratory strain of sindbis, sb, increased the number of plaque-forming units (pfu) detected on baby hamster kidney (bhk) cells rather than neutralizing virus infectivity. the elevated titers of sb approa ... | 1988 | 3413988 |
| differences in virion stability among sindbis virus pathogenesis mutants. | the structure of closely related sindbis virus strains, which differ in their virulence for neonatal mice, has been probed by measuring the sensitivity of virions to heat, varying concentrations of dithiothreitol (dtt), phenylglyoxal or low ph. attenuated mutants (sb-rl and sb-fp) were much more sensitive to loss of infectivity after heat or dtt treatment than either the prototype virulent strain (sb) or same-site virulent revertants of sb-rl. incubation of sb-rl virions in the presence of dtt i ... | 1988 | 3414183 |
| demonstration in vitro of temperature-sensitive elongation of rna in sindbis virus mutant ts6. | characterization of conditionally lethal mutants of alphaviruses, sindbis virus and semliki forest virus, has indicated that in almost all the rna-negative mutants the temperature-sensitive (ts) defect prevents the formation of active transcription complexes at nonpermissive temperature (40 degrees c), but such complexes retain activity at 40 degrees c if formed first at permissive temperature (30 degrees c). our recent results have extended the characterization of one exception to this finding: ... | 1988 | 3418782 |
| a single nucleotide change in the e2 glycoprotein gene of sindbis virus affects penetration rate in cell culture and virulence in neonatal mice. | the nucleotide sequence of the glycoprotein genes of fully virulent sindbis virus and derived mutants that have reduced neurovirulence for neonatal mice (attenuated mutants) has been determined. a single amino acid difference, arginine instead of serine at position 114 of the mature e2 glycoprotein, distinguished the prototype attenuated mutant from its virulent wild-type parent. virulent revertants of the attenuated mutant showed same-site reversion to the wild-type sequence. an identical singl ... | 1986 | 3462725 |
| production of infectious rna transcripts from sindbis virus cdna clones: mapping of lethal mutations, rescue of a temperature-sensitive marker, and in vitro mutagenesis to generate defined mutants. | we constructed full-length cdna clones of sindbis virus that can be transcribed in vitro by sp6 rna polymerase to produce infectious genome-length transcripts. viruses produced from in vitro transcripts are identical to sindbis virus and show strain-specific phenotypes reflecting the source of rna used for cdna synthesis. the cdna clones were used to confirm the mapping of the causal mutation of ts2 to the capsid protein. a general strategy for mapping sindbis virus mutations is described and wa ... | 1987 | 3479621 |
| fusion of sindbis virus with model membranes containing phosphatidylethanolamine: implications for protein-induced membrane fusion. | the ph-induced fusion of sindbis virus with model lipid membranes containing phosphatidylethanolamine has been studied using a quantitative fluorescence technique. the headgroup and acyl chain domains of the lipids have been altered systematically to determine their effect on fusion. unsaturated phosphatidylethanolamines (pe) have been found to promote fusion, either by themselves, or in combination with phosphatidylcholines (pc). cholesterol added to a mixture of unsaturated pe and pc was also ... | 1987 | 3580364 |
| topological organization of sindbis virus capsid protein in isolated nucleocapsids. | sindbis virus nucleocapsids were isolated from mature virions by a two-step purification method. detergent-treated virions were sedimented in sucrose gradients and the nucleocapsid peaks chromatographed on rnase-free sephadex g-200. the purified nucleocapsids displayed several morphologies when examined in the electron microscope. these morphologies, and the results of double-angle shadowing, suggest that the core of this enveloped virus has the shape of a regular icosahedron with a triangulatio ... | 1987 | 3590962 |
| is sindbis a simple picornavirus with an envelope? | a three-dimensional image reconstruction was performed from cryo-electron micrographs of isolated sindbis (snv) nucleocapsids. the isolated capsid is a smooth but fenestrated t = 3 structure. comparison with the nucleocapsid seen within the whole virion indicated that the structure resembles the swollen forms which some non-enveloped viruses adopt after removal of divalent cations. a sensitive comparison method was used to align snv capsid protein sequences with those of picornavirus vp3 capsid ... | 1987 | 3595557 |
| organization of the sindbis virus nucleocapsid as revealed by bifunctional cross-linking agents. | purified sindbis virus nucleocapsids were reacted with a variety of bifunctional protein-specific cross-linking agents. the products were analyzed in concentration-gradient polyacrylamide gels and amounts of various products determined. these studies indicated that available lysine residues within adjacent capsid proteins in purified intact nucleocapsids are separated by 6 a. the capsid proteins in intact nucleocapsids are cross-linked in a pattern predicted for discrete monomeric entities, rath ... | 1987 | 3656418 |
| antiviral effects of melia azedarach l. leaves extracts on sindbis virus-infected cells. | partially purified extracts from leaves of melia azedarach l. (ma) exert a broad range of antiviral effects on dna and rna viruses. the effect of ma on different stages of sindbis virus replicative cycle in bhk cells was investigated. under one-step growth conditions ma afforded a greater than 90% inhibition in virus yield if added to the cell cultures 2 h before or after infection, and when added 4 h after infection ma still caused a greater than 80% inhibition. analysis of early events followi ... | 1987 | 3688841 |