| mutational analysis of regulation of mhc and anti-viral genes. | ctl-mediated selection for loss of expression of mta by h-2-heterozygous sv40-transformed mouse fibroblasts (line 24sv) produced an unusual phenotypic class of maternally transmitted ag negative mutants defective in both mhc expression and in anti-viral activity. severely reduced surface expression of class i mhc ag from multiple loci of both haplotypes correlated with low levels of mhc h chain and beta 2-microglobulin mrna. inasmuch as ifn can up-regulate class i expression and some fibroblasts ... | 1991 | 1848575 |
| functional aspects of the capsid structure of mengo virus. | the three-dimensional structure of the mengo virus capsid has been determined at a resolution of 3.0 a. this achievement is discussed in an historical context, and the general features of picornavirus capsid design are presented. the dynamic functional aspects of the mengo virus capsid--namely its ability to interact with specific receptors on host cells, to dissociate and release the viral genomic rna into the cellular cytoplasm, to assemble with progeny rna molecules and form new virions, and ... | 1990 | 1965133 |
| the role of viruses and environmental factors in the induction of diabetes. | the development of iddm results from the destruction of pancreatic beta cells. genetic factors, various immune system alterations, and environmental factors have been studied as the possible causes of iddm. the concordance rate for developing iddm between monozygotic twins approaches 50%, suggesting that genetic factors are necessary, but nongenetic factors such as various immune system alterations and environmental factors also influence the clinical expression of genetic susceptibility. enviro ... | 1990 | 2073786 |
| attenuation of mengo virus through genetic engineering of the 5' noncoding poly(c) tract. | the murine cardioviruses, such as the mengo and encephalomyocarditis viruses, and the bovine aphthoviruses, such as foot-and-mouth disease virus, are distinguished among positive-strand rna viruses by the presence of long homopolymeric poly(c) tracts within their 5' noncoding sequences. although the specific lengths (60-350 bases) and sequence discontinuities (for example, uridine residues) that sometimes disrupt the homopolymer have served to characterize natural viral isolates, the biological ... | 1990 | 2153940 |
| relief of cytotoxicity and enhancement of interferon inducer activity of double-stranded rna by eukaryotic initiation factor 2. | double-stranded rna (dsrna) is a powerful interferon inducer but also possesses toxic properties. dsrna was shown previously to inhibit translation by causing the inactivation of eukaryotic initiation factor 2 (eif-2) and to bind tightly to this protein. the cytotoxicity of dsrna was analyzed simultaneously with the induction of interferon in murine fibroblast cultures. incubation of dsrna with eif-2 leads to a significant reduction in toxicity, concomitant with a marked stimulation of interfero ... | 1990 | 2154884 |
| conformational variability of a picornavirus capsid: ph-dependent structural changes of mengo virus related to its host receptor attachment site and disassembly. | the structure of mengo virus had been determined from crystals grown in the presence of 100 mm phosphate buffer at ph 7.4. it is shown that mengo virus is poorly infectious at the phosphate concentration similar to that in which it was crystallized. maximal infectivity is achieved at 10 mm phosphate or less in physiological saline. the phosphate effect is ameliorated when the ph is lowered to 4.6. although it has not been possible to study the crystal structure of the virus at low phosphate conc ... | 1990 | 2155508 |
| structural refinement and analysis of mengo virus. | the structure of mengo encephalomyelitis virus was refined at 3 a resolution with a final r-factor of 0.221 and a root-mean-square deviation from idealized bond lengths of 0.019 a for 10 a to 3 a data with f greater than or equal to 3 sigma(f). the hendrickson-konnert refinement was restrained by the phases derived from the molecular replacement averaging procedure and constrained by the icosahedral symmetry of the virus. the virus consists of 60 protomers each having three major subunits, vp1, ... | 1990 | 2156078 |
| the inhibition of mouse l-cell 45 s ribosomal rna processing is a highly uv-resistant property of vesicular stomatitis virus. | in mouse l cells infected with vesicular stomatitis virus (vsv), the synthesis of 45 s rrna and its conversion to 28 s and 18 s rrna are inhibited during the course of infection. evidence is presented that the lack of accumulation of stable rrna species results not only from the decreased transcription and processing of 45 s rrna, but also from an increased breakdown of pre-rrna or stable rrna during processing. in cells prelabeled with [3h]uridine and then infected, the 28 s and 18 s rrna speci ... | 1990 | 2162117 |
| the alpha subunit of eucaryotic initiation factor 2 is phosphorylated in mengovirus-infected mouse l cells. | infection of mouse l cells with mengovirus resulted in the activation of a protein kinase (pk) that selectively phosphorylated the small, 38,000-molecular-weight alpha subunit of eucaryotic initiation factor 2 (eif-2) in vitro. the mengovirus-activated kinase was detected in vitro approximately 3 h after virus adsorption. the ratio of phosphorylated to unphosphorylated eif-2 also increased in vivo between 3 and 7 h after adsorption. the virus-activated kinase fractionated with the ribosomal pell ... | 1990 | 2166823 |
| ph 2 instability of a mutant of mengovirus is related to its interferon sensitivity. | the is-1 mutant of mengovirus is 100 times more sensitive to interferon (ifn) than wild type, as measured by a yield reduction assay in the g3 line of mouse l cells, and is also much more readily inactivated at ph 2. neither isolated nor encapsidated rna is degraded under these conditions, which suggests that the ph-sensitive region resides on the virus coat. one-third of the viruses selected for resistance to low ph also showed enhanced resistance to ifn. attempts to isolate ifn resistant strai ... | 1990 | 2172408 |
| growth of wild-type and interferon-sensitive mengovirus in tk- l cells. | cells lacking thymidine kinase (tk) have been reported to fail to respond to the action of interferon (ifn). while some laboratories have confirmed this observation, others have failed to do so. we studied the effect of ifn on four freshly isolated tk- lines of mouse l cells infected with mengovirus. in all cases, normal antiviral activity was induced. the antiproliferative activity of ifn was studied using the parental l cell line, a tk- derivative, and a tk- (tk+) subline into which the tk gen ... | 1985 | 2409192 |
| comparative studies on (2'-5')oligoadenylate-related enzyme systems and the antiviral effect of interferon in two mouse cell lines which differ in (2'-5')oligoadenylate sensitivity of their protein synthesizing system. | effect of (2'-5')oligoadenylate (2-5a) on cellular and viral protein and rna syntheses was investigated with two mouse cell lines, l929 and lz (a subclone of l929). the oligonucleotide was introduced into the cells either by using calcium phosphate coprecipitation technique or by microinjection method. in l929 cells protein and viral rna syntheses were severely inhibited by 2-5a, whereas in lz cells, both were only slightly inhibited. the activities of 2-5a synthetase and double-stranded (ds)rna ... | 1985 | 2418128 |
| antiviral activity of a chemically stabilized 2-5a analog upon microinjection into hela cells. | 2-5a[ppp(a2'p)n5'a] has been implicated as a mediator in the antiviral action of interferon. its direct evaluation as an indicator of virus replication is hampered by two limitations: its inability to penetrate intact cells, and its rapid intracellular degradation by (2'-5')phosphodiesterase. these problems could be overcome by using a microinjection technique whereby a phosphodiesterase-resistant analog of 2-a, in which the 2'-terminals adenosine residue is replaced by 2-(9-adenyl)-6-hydroxy-me ... | 1986 | 2420642 |
| modulation of immune response and tumor development in tumor-bearing mice treated by the thymic factor thymostimulin. | thymostimulin (ts), a partially purified thymic factor, has a significant impact on tumor development in c57b1/6 mice inoculated with lewis lung carcinoma (3ll) cells, as judged by its effect on time of tumor appearance after tumor cell transplantation. in a previous study, we determined the conditions under which survival rate of the tumor-bearing mice can be significantly increased by ts treatment. in the study communicated here we analyzed host defense mechanisms that are modified by ts treat ... | 1987 | 2438037 |
| induction of an antiviral state by interferon in the absence of elevated levels of 2,5-oligo(a) synthetase and eif-2 kinase. | a series of clones has been derived from an interferon-resistant murine cell line, ltk- aprt-, and their antiviral properties have been characterized. in the parental ltk- aprt- line interferon is unable to establish antiviral properties or to increase the levels of 2,5-oligo(a) synthetase, the 2,5-oligo(a)-activated endonuclease f, 2',5'-phosphodiesterase, or eif-2 kinase. however, interferon did prevent replication of vesicular stomatitis, mengo virus, and reovirus in some of the derivative ce ... | 1988 | 2447700 |
| three-dimensional model of the capsid proteins of two biologically different theiler virus strains: clustering of amino acid difference identifies possible locations of immunogenic sites on the virion. | to explore structural features of the theiler murine encephalomyelitis virion, we have constructed a three-dimensional model of the capsid proteins (vp1, vp2, and vp3) of the bean strain based on the atomic coordinates of the closely related mengo virus. by superimposition of amino acid differences between bean virus and another theiler virus strain, gdvii, on the three-dimensional model, clusters of differences were found in four distinct sites; the vp1 third corner, the vp2 "puff," and the vp3 ... | 1988 | 2454472 |
| a model for the hepatitis b virus core protein: prediction of antigenic sites and relationship to rna virus capsid proteins. | the sequences of the core proteins from several serotypes of human hepatitis b virus and related mammalian and avian hepadnaviruses are aligned with the vp3 capsid protein of mengo virus, a picornavirus. the homology indicates an eight-stranded antiparallel beta-barrel fold for the hepatitis protein, as observed in the tertiary structure of the picornavirus protein. the locations of known antigenic sites and other modifications are consistent with this structure for the core protein. the predict ... | 1988 | 2456212 |
| alteration of amino acid 101 within capsid protein vp-1 changes the pathogenicity of theiler's murine encephalomyelitis virus. | chronic theiler's murine encephalomyelitis virus infection of susceptible mice is an animal model for human demyelinating diseases. previously we described an altered and diminished pattern of central nervous system disease in immunocompetent sjl/j mice infected with a variant virus. this variant virus h7a6-2 was selected with a neutralizing mab recognizing the capsid protein vp-1 of theiler's virus. here we characterize the variant virus by elisa and neutralization assays and by sequencing sele ... | 1989 | 2479706 |
| interferon-gamma is cytotoxic for normal mouse fibroblasts: enhancement by tumor necrosis factor and interleukin 1. | tumor necrosis factor (tnf) and interleukin-1 (il-1) are cytotoxic for certain tumor cells but have a proliferative effect on normal cells. here we show that interferon-gamma (ifn-gamma) can be cytotoxic for normal cells, in particular mouse embryonic fibroblasts. the cytotoxicity effect is observed with immuno-purified recombinant mouse ifn-gamma (muifn-gamma) at concentrations of 1,000 i.u./ml and can be neutralized by anti-muifn-gamma monoclonal antibodies. the effect appears 48 h after initi ... | 1989 | 2497277 |
| 2'-5'-oligoadenylate synthetase gene expression in normal and murine sarcoma virus-transformed nih 3t3 cells. | mouse fibroblasts transformed by murine sarcoma virus (msv) are highly sensitive to the antiproliferative effect of interferon (ifn) (m. bakhanashvili, d. h. wreschner, and s. salzberg, cancer res. 43:1289-1294, 1983). to elucidate the mechanism leading to this ifn sensitivity, the expression of the 2'-5'-oligoadenylate synthetase (2-5a synthetase) gene, the presence of the 2-5a synthetase protein, and the level of its enzymatic activity were determined in ifn-treated and untreated cultures. nih ... | 1989 | 2536824 |
| mengo virus maturation is accompanied by c-terminal modification of capsid protein vp1. | we have demonstrated that the c-terminal ends of the vp1 proteins of mengo virus undergo a postassembly trimming of three amino acid residues. a variable proportion of the vp1 molecules isolated from purified virions terminate at glu 277, which corresponds to the initial viral protease 3c cleavage site. the remainder of the vp1 molecules terminates at leu 274. when chymotrypsin treatment is included in the virus purification procedure, leu 274 is the exclusive c-terminal amino acid of the vp1 mo ... | 1989 | 2536988 |
| cloning and synthesis of infectious cardiovirus rnas containing short, discrete poly(c) tracts. | mengovirus rna transcripts with 5' noncoding poly(c) tracts of c8, c12, and c13uc10 have been synthesized in vitro from cdna clones and shown to be infectious to hela cells. a chimeric clone has also been constructed which links the 5' end from one mengovirus clone (299 nucleotides, containing c13uc10) to a 7,424-base fragment derived from the 3' end of encephalomyocarditis (emc) virus. progeny virus isolated after transfection with the clone-derived rnas had the same poly(c) tracts, mengovirus- ... | 1989 | 2538661 |
| [use of direct calorimetry for continuously following the course of experimental infections in the mouse]. | to obtain information about early symptoms of infection measurements of heat production were performed in experimentally infected animals. as a model mengo virus-infected mice were used. construction and physical properties of the flow calorimeter device are described. fever was not detected by method used. however, deviations from normal behaviour of the animals were demonstrated as a result of the relationship between motoric activity and heat produced. furthermore, the method may be particula ... | 1989 | 2551106 |
| structure determination of mengo virus. | the structure of mengo virus was determined to 3.0 a resolution using human rhinovirus 14 as an initial phasing model at 8.0 a resolution. oscillation diffraction photographs were collected at the cornell high energy synchrotron source using orthorhombic mengo virus crystals. the crystal space group was p2(1)2(1)2(1), a = 441.4, b = 427.3 and c = 421.9 a, with one icosahedral particle per asymmetric unit, giving 60-fold noncrystallographic redundancy. the orientations of the four viral particles ... | 1989 | 2559754 |
| [transmission cycles of arboviruses in madagascar]. | some arboviruses are highly pathogenic for men or animals. arboviruses epidemiological patterns in madagascar were determined by entomological, serological, and virological surveys. we listed potentials arboviruses vectors in madagascar. entomological results generated by us during five years, as well as prior to, are shown. we caught more than 150,000 hematophagous arthropods, belonging to 107 species at least. 3 of these species were new. 4183 inoculation pools were done. we studied serollogic ... | 1989 | 2576622 |
| [arbovirus transmission cycles in madagascar]. | some arboviruses are highly pathogenic for men or animals, arboviruses epidemiological patterns in madagascar were determined by entomological, serological, and virological surveys. we listed potentials arboviruses vectors in madagascar. entomological results generated by us during five years, as well as prior to, are shown. we caught more than 150,000 hematophagous arthropods, belonging to 107 species at least. 3 of these species were new. 4183 inoculation pools were done. we studied serologica ... | 1989 | 2751393 |
| possible mechanisms in the pathogenesis of virus-induced diabetes mellitus. | insulin-dependent diabetes mellitus results from destruction of pancreatic beta cells. viruses and autoimmunity have been implicated as possible causes of beta cell destruction in genetically predisposed individuals. the evidence for viruses comes largely from experiments in animals, but several studies in humans point to viruses as triggers in the pathogenesis of diabetes in some cases. in animal models, at least 4 different possible mechanisms for virus-induced diabetes have been proposed. the ... | 1987 | 2824113 |
| characterization and specificity of humoral immune responses to theiler's murine encephalomyelitis virus capsid proteins. | humoral antibody responses to theiler's murine encephalomyelitis virus (tmev) capsid proteins were examined. rabbit antisera produced against the native bean strain of tmev and against the isolated capsid proteins (vp1, vp2 and vp3) were tested for their ability to bind or neutralize virus and to inhibit the virus-induced haemagglutination of human o+ erythrocytes. western immunoblotting analysis showed that isolated vp1, vp2 and vp3 each primed for a specific antibody response, but that native ... | 1987 | 2826657 |
| selection and characterization of interferon response mutants from mouse l929 fibroblast cells. | interferon (ifn) response mutants were selected from mouse l929 fibroblast cells and their specific resistance to is-1, an ifn-sensitive mutant of mengovirus, was studied. the standard l cell subline used in our laboratory (g3), is resistant to is-1 infection after pretreatment with low levels of ifn. two clonal sublines that support the growth of is-1 in the presence of ifn (as-4 and ta-6) were isolated from it, and two revertant lines (as-4r1 and ta-6r1) were subsequently selected from as-4 an ... | 1988 | 2828512 |
| conservation of the putative receptor attachment site in picornaviruses. | a deep canyon or pit on the surfaces of human rhinovirus 14 and mengo virus, respectively, has been proposed as a putative receptor binding site. amino acids lining the surface of the canyon or pit have been identified and show greater conservation than other surface residues. | 1988 | 2835857 |
| prediction of three-dimensional models for foot-and-mouth disease virus and hepatitis a virus. | atomic models of foot-and-mouth disease virus and hepatitis a virus have been predicted using amino acid sequence alignments with the known structures of mengo virus and human rhinovirus 14. the structural models are consistent with results of biochemical and immunological studies. the two viruses appear to have surface features exceedingly different than those of other picornaviruses. they also have large hydrophobic cavities within vp1 suggesting that it may be possible to inhibit their infect ... | 1988 | 2845659 |
| regulation of muifn-alpha/beta and muifn-gamma-induced antiviral states: differential effects with different challenge viruses and lack of correlation with 2'5' oligoadenylate synthetase levels. | the muifn-alpha/beta and muifn-gamma induced antiviral states which are directed against mengovirus have been shown previously to be differentially regulated. following interferon removal, the muifn-alpha/beta-induced antiviral state decays rapidly, while the muifn-gamma-induced antiviral state increases dramatically. to determine whether these observations with mengovirus represent part of a general phenomenon, these studies have been extended using vesicular stomatitis virus and vaccinia virus ... | 1988 | 2845725 |
| 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 |
| dynamic model of the pathogenesis of mengo virus infection in mice. | a mathematical model of the pathogenesis of experimental mengo virus infection in mice has been developed and fitted using kinetic data of both virus multiplication in different organs and mortality. the behaviour of the model proved to be bistable. in contrast to the widely accepted hypothesis that an acutely virus-infected host dies when virus replication has attained a critical level in the main target organ, the present results showed the following: the maximum virus titre in brain, the main ... | 1987 | 2892380 |
| [arboviroses in the region of nosy-bé, madagascar. serologic and entomologic data]. | since 1977, the pasteur institute of madagascar has been studying, during six surveys, the arboviruses of nosy-be area, in the north-west of madagascar. 47.2% out of 271 human sera and 11.3% out of 151 sera of lemurs, tested for antibodies to 16 arboviruses by the haemagglutination inhibition test, are positive. the results show an important prevalence of flaviviruses. west nile and dengue 1 viruses were probably circulating some years before the surveys. antibodies against sindbis and rift vall ... | 1988 | 2900082 |
| evidence that ifn-alph/beta induces two antiviral states active against different viruses. | ifn-alpha/beta has been suggested to require only one round of mrna and protein synthesis to induce an antiviral state. we have examined the mechanism of induction of the antiviral states shown against three types of viruses: mengovirus (plus strand, sense rna), vesicular stomatitis virus (vsv, minus strand rna), and vaccinia virus (dna). mouse l cells were treated with ifn-alpha/beta and cycloheximide and then with actinomycin d on a schedule which allowed only one round of mrna and protein syn ... | 1985 | 2987400 |
| evidence for the presence of an inhibitor on ribosomes in mouse l cells infected with mengovirus. | after infection of mouse l cells with mengovirus, there is a rapid inhibition of protein synthesis, a concurrent disaggregation of polysomes, and an accumulation of 80s ribosomes. these 80s ribosomes could not be chased back into polysomes under an elongation block. the infected-cell 80s-ribosome fraction contained twice as much initiator methionyl-trna and mrna as the analogous fraction from uninfected cells. since the proportion of 80s ribosomes that were resistant to pronase digestion also in ... | 1985 | 2993647 |
| [in vitro effectiveness of new antiviral substances. 1. results of screening studies against selected picornaviruses]. | a number of 3108 new synthetic compounds were subjected to a screening for antiviral activity. the screening resulted in the selection of numerous drugs active against mengovirus in vitro. some drugs were also active against coxsackie viruses a9 and b1; most of the drugs efficient against coxsackie virus a9 also showed activity against mengovirus. quantitative investigations--such as the determination of a therapeutic index or of the inhibition of infectious virus yields in one-step growth cycle ... | 1985 | 2994288 |
| perspectives on the role of viruses in insulin-dependent diabetes. | insulin-dependent diabetes mellitus (iddm) results from the destruction of pancreatic beta cells. viruses have been suggested as one of the possible causes. the evidence for viruses comes largely from experiments in animals, but several studies in humans also point to viruses as a trigger of this disease in some cases. encephalomyocarditis (emc) virus, mengovirus (2t), and coxsackie b4 virus infect and destroy pancreatic beta cells when inoculated into mice. this results in hypoinsulinemia and h ... | 1985 | 2996865 |
| a comparative study on the translation of cardiovirus rnas in rabbit reticulocyte lysates. | in rabbit reticulocyte lysates the rnas of encephalomyocarditis (emc) virus, mengovirus, and mous-elberfeld (me) virus directed the synthesis of similar sets of products. moreover, the viral protease synthesized from any one of the three viral rnas could cause cleavage of the viral capsid precursor proteins synthesized from any of the three rnas. however, the three rnas differed in their dependence on trna supplementation (to the lysates) for effective translation. in the absence of trna supplem ... | 1985 | 2998057 |
| cytotoxic t lymphocytes and natural killer cell activity in the course of mengo virus infection of mice. | inbred c57bl/6 mice were inoculated intraperitoneally (i.p.) with mengo virus. the activity of cytotoxic t lymphocytes (ctl) and natural killer (nk) cells were measured during the first 22 days following infection. the ctl response began 7 days after virus inoculation, persisted for at least 22 days and was related to the dose of the virus inoculated. nk cell activity was elevated within 24 hr, reached its peak level on the fourth day and declined to normal levels on the eleventh day after expos ... | 1985 | 3000928 |
| toward an in vitro system for picornavirus assembly: purification of mengovirus 14s capsid precursor particles. | mengovirus 14s subviral protein particles generated in infected l cells and in a cell-free translation system primed with mengovirus rna were purified by sucrose gradient centrifugation and immunoaffinity chromatography. the preparations from both sources contained essentially pure proteins epsilon, alpha, and gamma, as was demonstrated in terms of virus-specific proteins (by autoradiography) and total protein content (by silver staining of sodium dodecyl sulfate-polyacrylamide electrophoresis g ... | 1986 | 3001350 |
| antiviral activity towards vsv and mengo virus of a chemically stabilized 2-5a analog upon microinjection into hela cells. | | 1985 | 3008170 |
| regulation of interferon-induced antiviral states: contrasting profiles of decay in response to the removal of muifn-alpha, muifn-beta and muifn-gamma. | the stabilities of the antiviral states induced by different types of murine interferons (ifns) were compared to gain insight into possible differences in the modes of regulation of their respective antiviral states. both type i (muifn-alpha and muifn-beta) and type ii (muifn-gamma) ifns were employed to establish antiviral states against mengovirus in mouse l-929 cells. at various times after ifn treatment, the ifns were removed and the stability of the antiviral states was determined by single ... | 1986 | 3016159 |
| independent regulation of the antiviral states induced by muifn-alpha/beta and by muifn-gamma. | the stability profiles of the antiviral states induced in l-929 cells against mengovirus by murine interferons muifn-alpha/beta and by muifn-gamma were shown to be different. treatment of cells with combinations of ifn-alpha/beta and ifn-gamma have previously been shown to result in a potentiated expression of the antiviral state. here we report studies of the stabilities of the antiviral states induced by various combinations of ifn-alpha/beta and ifn-gamma and that the regulation of the antivi ... | 1986 | 3020160 |
| selection and characterization of an interferon-responsive clonal cell line of hela cells. | hela cells generally do not respond well to interferon (ifn). we have used is-1, an ifn-sensitive mutant of mengovirus, to select a clone of ifn-responsive hela cells (f-h12). at moderate levels of human alpha/beta ifn, is-1 yields were fivefold lower in these cells than in similarly protected control cells. in contrast, wild-type mengovirus, vesicular stomatitis virus and a wild-type and thymidine kinase-negative strains of herpes simplex virus type 1 grew equally well in both cell lines. by a ... | 1986 | 3023528 |
| a kinase able to phosphorylate exogenous protein synthesis initiation factor eif-2 alpha is present in lysates of mengovirus-infected l cells. | infection of mouse l929 cells by mengovirus resulted in the expression of a kinase activity that selectively phosphorylated the small, 38,000-molecular-weight subunit of eucaryotic initiation factor 2 and histone h2. this kinase activity was independent of host cell rna synthesis and was located in the postribosomal supernatant (s-100 fraction) early after infection (up to 3 h). at later times after infection (5 h), kinase activity was also associated with the polysome fraction. the kinase prese ... | 1986 | 3023653 |
| the atomic structure of mengo virus at 3.0 a resolution. | the structure of mengo virus, a representative member of the cardio picornaviruses, is substantially different from the structures of rhino- and polioviruses. the structure of mengo virus was solved with the use of human rhinovirus 14 as an 8 a resolution structural approximation. phase information was then extended to 3 a resolution by use of the icosahedral symmetry. this procedure gives promise that many other virus structures also can be determined without the use of the isomorphous replacem ... | 1987 | 3026048 |
| structural and physiological properties of mengovirus: avirulent, hemagglutination-defective mutants express altered alpha (1 d) proteins and are adsorption-defective. | structural and physiological properties of two mutants of mengovirus, 205 and 280, were compared to those of wild-type virus to understand the molecular basis of changes exhibited in their biological function. two dimensional gel electrophoresis of wild-type and mutant structural proteins revealed alterations in the isoelectric character of the alpha (1 d) protein of both mutant 205 and 280. these data suggest that alterations in the alpha (1 d) protein may be responsible for the phenotypic chan ... | 1987 | 3028339 |
| biological properties of mengovirus: characterization of avirulent, hemagglutination-defective mutants. | biological properties of two mengovirus mutants, 205 and 280, were compared to those of wild-type virus. the mutants exhibited alterations in plaque morphology, hemagglutination, and virulence in mice, but were not temperature-sensitive. agglutination of human erythrocytes by mengovirus was dependent on the presence of sialic acid on the erythrocyte surface; however, free sialic acid failed to inhibit hemagglutination. glycophorin, the major sialoglycoprotein of human erythrocyte membranes, exhi ... | 1987 | 3028343 |
| the effect of mengovirus infection on lipid synthesis in cultured ehrlich ascites tumor cells. | the concept of generally increased lipid synthesis during the initial 2/3 of picornaviral infectious cycles, held by several authors, needs differentiation. in mengovirus-infected ehrlich ascites tumor cells, an increase in the rate of synthesis of phosphatidylcholine could be confirmed, but for phosphatidylethanolamine constant to decreasing rates of synthesis were found. moreover, phosphatidylinositol was increasingly synthesized in the midst of the infectious cycle. the changes observed might ... | 1987 | 3031411 |
| host involvement in vaccinia virus replication. | nutrient-depleted conditions, which induced an inhibited state in uninfected cell monolayers, rendered the cells nonpermissive for vaccinia virus, while not affecting their ability to support propagation of an unrelated mengovirus. when the inhibited state was reversed, the ability to propagate vaccinia virus was restored. the inhibited cells retained the ability to support some early-induced events (thymidine kinase synthesis and its arrest, which are dna synthesis-independent functions in a mo ... | 1986 | 3032843 |
| analysis of the complete nucleotide sequence of the picornavirus theiler's murine encephalomyelitis virus indicates that it is closely related to cardioviruses. | theiler's murine encephalomyelitis viruses (tmev) are naturally occurring enteric pathogens of mice which constitute a separate serological group within the picornavirus family. persistent tmev infection in mice provides a relevant experimental animal model for the human demyelinating disease multiple sclerosis. to provide information about the tmev classification, genome organization, and protein processing map, we determined the complete nucleotide sequence of the tmev genome and deduced the a ... | 1987 | 3033278 |
| 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 |
| monoclonal antibody-aided characterization of cellular p220 in uninfected and poliovirus-infected hela cells: subcellular distribution and identification of conformers. | a monoclonal antibody directed against the mr-220,000 subunit (p220) of the mrna cap-binding complex has been prepared and used to analyze the sucrose gradient sedimentation and subcellular location of p220 and its poliovirus-induced cleavage products. the antibody reacted with p220 on immunoblots of cell lysates from uninfected cells, but only with several smaller polypeptides, the p220 cleavage products, in cell lysates from poliovirus-infected cells. the sedimentation of p220 antigens from un ... | 1987 | 3039164 |
| the synthesis of a particle-forming cellular protein is enhanced by mengo virus infection. | we have detected a cellular protein which not only escapes the shutoff of host translation induced by mengo virus, but is synthesized in increasing amounts during mengo virus infection. the protein has an apparent molecular weight of 20,000 and is contained in a remarkably stable cytoplasmic particle with a sedimentation coefficient of approximately 16 s in sucrose gradients. in the electron microscope this particle appears as a sphere of approximately 12 nm diameter. the synthesis of the protei ... | 1987 | 3039732 |
| [arbovirus infections on the island of nosy-be; serologic and entomologic findings]. | since 1977, the pasteur institute of madagascar has been studying, during six surveys, the arboviruses of nosy-be area, in the north-west of madagascar. 47.2 p. 100 out of 271 human sera and 11.3 p. 100 out of 150 animal sera (mostly from lemurs), tested for antibodies to 16 arboviruses by the haemagglutination inhibition test, are positive. the results show an important prevalence of flaviviruses. west-nile and dengue 1 viruses were probably circulating some years before the surveys. antibodies ... | 1988 | 3242421 |
| effects of environmental factors on the development of insulin-dependent diabetes mellitus. | the development of insulin-dependent diabetes mellitus is thought to be dependent on either the autoimmunity or the interaction of environmental agents with the pancreatic beta cells, or both in a genetically susceptible host. as environmental factors affecting the induction of type i diabetes, diabetogenic chemicals and viruses are likely candidates as primary injurious agents for pancreatic beta cells in man and animal. a number of structurally diverse chemicals including alloxan, streptozotoc ... | 1987 | 3315367 |
| implications of the picornavirus capsid structure for polyprotein processing. | mature picornaviral proteins are derived by progressive, posttranslational cleavage of a precursor polyprotein. these cleavages play a role in the control of virus functions. although the processed termini are separated by as much as 75 a in the native virus capsid, the fold and arrangement of polypeptide chains in a protomer before proteolysis are likely to be similar to that found in the mature virus. the three-dimensional structures of rhinovirus and mengo virus suggest that the cleavage site ... | 1987 | 3467351 |
| physiological changes induced in cardiac myocytes by cytotoxic t lymphocytes. | the "lethal hit" induced by viral specific, sensitized, cytotoxic t lymphocytes (ctl) attacking virus-infected heart cells is important in the pathogenesis of viral myocarditis and reflects the key role of ctl in this immune response. the mechanisms involved are incompletely understood. studies of the physiological changes induced in mengovirus-infected, cultured, neonatal, rat heart cells by ctl that had been previously sensitized by the same virus are presented. the ctl were obtained from sple ... | 1987 | 3492921 |
| cellular changes attending mengovirus-induced cytolysis of mouse l-cells. | | 1971 | 4108194 |
| structure and infectivity of picornaviral rna encapsidated by cowpea chlorotic mottle virus protein. | poliovirus and mengo virus rna were shown to associate efficiently with cowpea chlorotic mottle virus protein to form pseudovirions. the sedimentation coefficient for the pseudovirions was similar to that of poliovirus, and electron microscope observations showed the mengo pseudovirions to be similar in size to mengo virus. such pseudovirions were infectious and were more resistant to ribonuclease than viral rna; however, under our assay conditions, their infectivity was about equal to that of v ... | 1973 | 4128376 |
| effect of ultraviolet light on mengovirus: formation of uracil dimers, instability and degradation of capsid, and covalent linkage of protein to viral rna. | uv irradiation of purified mengovirus resulted in a very rapid inactivation of the infectivity of the virions (d(37) [37% survival dose] = 700 ergs/mm(2)) which correlated in time with the formation of uracil dimers in the viral rna. during the first 2 min of irradiation, an average of 1.7 uracil dimers were formed per pfu of virus inactivated. hemagglutination activity of the virions began to decrease only after a lag period of about 5 min and at a much lower rate (d(37) = 84,000 ergs/mm(2)). t ... | 1974 | 4132673 |
| synthesis of viral-specific polypeptides in mengo virus-infected l cells: evidence for asymmetric translation of the viral genome. | | 1974 | 4138486 |
| pathogenicity of mengo virus to mice. i. virological studies. | | 1974 | 4156158 |
| inhibition of rna synthesis in hela and l cells by mengovirus. | | 1967 | 4163399 |
| mengovirus replication in novikoff rat hepatoma and mouse l cells: effects on synthesis of host-cell macromolecules and virus-specific synthesis of ribonucleic acid. | novikoff cells (strain n1s1-67) and l-67 cells, a nutritional mutant of the common strain of mouse l cells which grows in the same medium as n1s1-67 cells, were infected with mengovirus under identical experimental conditions. the synthesis of host-cell ribonucleic acid (rna) by either type of cell was not affected quantitatively or qualitatively until about 2 hr after infection, when viral rna synthesis rapidly displaced the synthesis of cellular rna. the rate of synthesis of protein by both ty ... | 1968 | 4176992 |
| delay of mengovirus-induced cytopathology in mitotic l-cells. | the time course and extent of mengovirus production were the same in metaphase-arrested and interphase l-cells, yet the expression of cytopathology was delayed several hours in metaphase cells. | 1970 | 4194170 |
| mengovirus replication. 3. virus reproduction in chinese hamster ovary cells. | | 1965 | 4283990 |
| mengovirus replication. iv. inhibition of chinese hamster ovary cell division as a result of infection with mengovirus. | | 1965 | 4283992 |
| the effect of mengovirus infection on the activity of the dna-dependent rna polymerase of l-cells. ii. preliminary data on the inhibitory factor. | | 1964 | 4284277 |
| effect of cortisone on activation of lysosomal enzymes resulting from mengovirus infection of l-929 cells. | | 1966 | 4285387 |
| inhibition of mengo virus by interferon. | gauntt, charles j. (the university of texas, austin), and royce z. lockart, jr. inhibition of mengo virus by interferon. j. bacteriol. 91:176-182. 1966.-the inhibition of mengo virus replication in l cells resulting from interferon was studied quantitatively. interferon was titrated on l cells with western equine encephalomyelitis (wee) virus as the challenge virus. one protective unit (pu) of interferon is the least amount of interferon which prevents cytopathic effects when a large multiplicit ... | 1966 | 4285530 |
| the effect of polyanions and polycations on mengo virus--l cell interaction. | | 1965 | 4285585 |
| effect of interferon on polymerization of single-stranded and double-stranded mengovirus ribonucleic acid. | gordon, irving (university of southern california, los angeles), sara s. chenault, douglas stevenson, and jean d. acton. effect of interferon on polymerization of single-stranded and double-stranded mengovirus ribonucleic acid. j. bacteriol. 91:1230-1238. 1966.-the effect of interferon on actinomycin-resistant mengovirus ribonucleic acid (rna) replication in l cells was investigated to determine whether defective or partially polymerized rna products were made and whether synthesis of any specif ... | 1966 | 4286447 |
| [viral growth and interferon production in mice on a starvation diet infected by mengo virus]. | | 1965 | 4286985 |
| symposium on replication of viral nucleic acids. 3. replication of mengovirus ribonucleic acid. | | 1966 | 4287031 |
| replication of mengovirus. i. effect on synthesis of macromolecules by host cell. | plagemann, peter g. w. (western reserve university, cleveland, ohio), and h. earle swim. replication of mengovirus. i. effect on synthesis of macromolecules by host cell. j. bacteriol. 91:2317-2326. 1966.-the replication of mengovirus was studied in two strains of novikoff (rat) hepatoma cells propagated in vitro. the replicative cycle in both strains required 6.5 to 7 hr. infection resulted in a marked depression of ribonucleic acid (rna) and protein synthesis by strain n1s1-63. inhibition of r ... | 1966 | 4287585 |
| replication of mengovirus. ii. general properties of the viral-induced ribonucleic acid polymerase. | plagemann, peter g. w. (western reserve university, cleveland, ohio), and h. earle swim. replication of mengovirus. ii. general properties of the viral-induced ribonucleic acid polymerase. j. bacteriol. 91:2327-2332. 1966.-mengovirus induces the appearance of a ribonucleic acid (rna) polymerase activity in novikoff hepatoma cells which is readily distinguished from the deoxyribonucleic acid (dna)-dependent rna polymerase since it is not inhibited by actinomycin d or deoxyribonuclease, but is inh ... | 1966 | 4287586 |
| respiration of mengovirus-infected l-929 cells. | iglewski, w. j. (the pennsylvania state university, university park), and e. h. ludwig. respiration of mengovirus-infected l-929 cells. j. bacteriol. 92:733-738. 1966.-polarographic techniques were employed to study the oxidative metabolism of l-929 cells during a one-step mengovirus growth cycle. virus maturation began 3.5 hr after infection and was complete with 7 hr. virus maturation was accompanied by a decreased rate of endogenous respiration and an increased rate of oxidation of succinate ... | 1966 | 4288496 |
| cytopathology of mengovirus infection. i. relationship between cellular disintegration and virulence. | | 1967 | 4290639 |
| cytopathology of mengovirus infection. ii. proliferation of membranous cisternae. | | 1967 | 4290640 |
| a sensitive assay for infectivity of mengovirus rna in l cells. | | 1967 | 4291297 |
| passage of mengovirus through the zona pellucida of the mouse morula. | | 1967 | 4291335 |
| statolon-induced resistance of mice to mengovirus. | mice receiving statolon intraperitoneally were 1,000 times more resistant to intraperitoneal challenge with mengovirus than were untreated controls. protection was afforded when statolon was administered 1 day before or 1 day after intraperitoneal inoculation with the virus. no therapeutic effect was observed when treatment with statolon was delayed for 2 days or more after virus infection. exposure of mice to a simulated space cabin environment did not increase their susceptibility to the letha ... | 1967 | 4291957 |
| isolation of a series of mengo virus variants differing in sensitivity to polyanions. | | 1967 | 4291974 |
| physico-chemical studies of three variants of mengo virus and their constituent ribonucleates. | | 1967 | 4292199 |
| sensitivity to, and production of interferon by three variants of mengo virus. | | 1967 | 4292852 |
| influence of heavy water (d2o) on the multiplication of adeno and mengo virus. | | 1967 | 4294141 |
| treatment of mengovirus infection in mice with statolon. | a single intraperitoneal injection of statolon was shown to exert a therapeutic effect on mice previously injected with the large plaque-forming variant of mengovirus. the ld(50) and survival time data demonstrated that such treatment was effective when given 2 to 48 hr after infection. no protective effect was apparent when statolon was administered 3, 4, or 5 days after the viral challenge. it was concluded that statolon, or other similar interferon inducers, may be of therapeutic value in ins ... | 1967 | 4294823 |
| reversible inhibition of induction of mengovirus rna polymerase and of virus maturation in novikoff rat hepatoma cells by phenethyl alcohol. | | 1968 | 4295916 |
| duration of prophylactic effect of statolon against mengovirus in mice. | intraperitoneal injection of statolon into mice is known to exert a protective effect against a subsequent infection with a variety of viruses owing to stimulation of production of interferon. to study the duration of such protection, groups of mice were treated with 350 mug of statolon at 69, 55, 41, 27, 13, 6, or 1 day prior to a challenge with mengovirus. other groups were treated with 760 mug at 1 to 6 days before challenge. ten days after inoculation with the virus, ld(50) determinations we ... | 1968 | 4297000 |
| effect of statolon-induced interferon on antibody formation. | the effect of statolon-induced interferon on immune response was investigated. young adult swiss albino mice were immunized with chicken red blood cells or infectious mengovirus. the red blood cells were injected three times and the virus twice at 2-week intervals, with or without treatment with statolon 24 hr before the inoculations. the effect of interferon on antibody formation was measured by determinations of hemagglutinating, hemolytic, and virus-neutralizing antibodies in the sera of trea ... | 1968 | 4298812 |
| [characterization of various representatives of the columbia-sk-virus group with fluorescent antibodies. i. the reproduction cycle of mengo virus in l cells]. | | 1967 | 4299732 |
| enhancement of mengovirus nucleic acid infectivity by putrescine. | | 1968 | 4300093 |
| destruction of l cells by mengo virus: use of interferon to study the mechanism. | interferon, when added to l cells, inhibited the synthesis of infectious mengo viral ribonucleic acid, hemagglutinins, and infectious virus by 85 to 95%. serum-blocking antigens were also reduced by the action of interferon, but threefold excess amounts of these antigens accumulated in interferon-treated cultures above the amounts expected for the quantity of infectious virus that was produced in these cultures. radioautographic analysis showed that 28 to 36% of the cells of an interferon-treate ... | 1968 | 4301505 |
| replication of mengovirus in hela cells preinfected with nonreplicating poliovirus. | the replication of mengovirus in hela cells preinfected with poliovirus in the presence of 10(-3) m guanidine was investigated. although host cell protein synthesis is inhibited by the presence of nonreplicating poliovirus, it is found that mengovirus ribonucleic acid (rna) and protein synthesis proceed normally under the same conditions. furthermore, no effects on mengovirus growth by poliovirus can be detected either when mengo protein synthesis is interrupted by acti-dione or when its rna syn ... | 1968 | 4302186 |
| physical and chemical studies of mengo virus variants. ii. chromatographic behavior and chemical composition. | | 1969 | 4304576 |
| the interaction of tritium-labelled mengo virus rna and l cells: the effects of dmso and deae-dextran. | | 1969 | 4305634 |