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application of the enzyme linked immunosorbent assay to the detection and identification of foot-and-mouth disease viruses.an indirect enzyme linked immunosorbent assay (elisa) was applied to the detection and identification of foot-and-mouth disease (fmd) virus types. the test proved successful for the specific detection of virus from infected tissue culture, and from epithelial tissues from bovines suspected of having fmd. the elisa compared favourably with the complement fixation (cf) test, being more sensitive and unaffected by anticomplementary factors.1979229162
a blastogenic test for foot-and-mouth disease.a blastogenic test to detect peripheral blood leukocytes specifically sensitized to foot-and-mouth disease virus antigen is described. the test is carried out in microtitre plates and optimum conditions were found by titration. these employed 7.5 x 10(5) cells/well and 20 complement fixing units of antigen. peak [3h]thymidine incorporation was found to take place at 2-3 days.1979229161
inhibition of foot and mouth disease virus and procapsid synthesis by zinc ions. brief report.zinc ions inhibit virus production and viral rna synthesis in fmdv infected-bhk 21 cells. the degree of inhibition depends upon the zinc concentration and the time of addition of the drug. a differential inhibition on virus and procapsids synthesis was observed.1979229792
viral interference phenomena induced by foot-and-mouth disease temperature-sensitive mutants in bovine kidney cells.cultures of bovine kidney (bk) cells infected with temperature-sensitive (ts) mutants of foot-and-mouth disease virus (fmdv) were incubated at 38.5 degrees c, a temperature nonpermissive for mutant virus growth and rna synthesis. the cells were subsequently resistant to viral growth and rna synthesis when superinfected with wild-type fmdv and with heterologous fowl plague virus. the extent of interference was proportional to the multiplicity of infection of the ts mutant. it increased with time ...1979229787
[foot-and-mouth disease in buffaloes (bubalus bubalis, linnaeus, 1758): search of antiantigen antibodies and isolation of the virus].the immune response to virus-infection-associated (via) antigen was studied in 379 indian buffalos (bubalus bubalis). these animals were vaccinated three times a year with commercial acetylethyleneimine (aei)--inactivated foot-and-mouth disease vaccines under field conditions. two months after the last vaccination, antibody against virus-infection-associated (via) antigen was found in 23 per cent. foot-and-mouth disease virus -- (fmdv) type c "waldmann" was isolated from oesophageal/pharyngeal f ...1979233417
a new method for the isolation of undegraded fmdv-specific rna from infected bhk cells.fractionation of foot-and-mouth disease virus infected cells by currently described procedures, leads to the appearance of variable amounts of heterogeneous single-stranded rna fragments. a new method based upon the fractionation of cultured cells at extremely low temperatures has been developed to minimize the degradation of the viral rnas by cellular nucleases. it was shown that the viral rnas obtained by this procedure were almost non-degraded, and similar to those found in other picornavirus ...1979229806
[occurrence of an increased reaction to challenge infection after vaccination with aerosols of inactivated foot-and-mouth disease virus]. 1976961209
[treatment of swine cell line with antibiotics: effect on growth kinetics and susceptibility to foot-and-mouth disease virus and to mycoplasma-like organisms].cell cultures treated with tylosin tartrate and kanamycin sulphate antibiotics were studied in relation to the cell growth rate, the susceptibility to the foot-and-mouth disease virus and to the microorganism eradication. these treatments did not affect the cell growth rate and the cell behavior to the viral infection. on the other hand, the decontamination of the intracytoplasmatic formas of mycoplasma-like organism was not observed.1979233199
[formation of immunity in sheep inoculated with varying doses of the foot-and-mouth disease virus 0194]. 1979217141
[isolation of bovine cell lines and susceptibility to foot-and-mouth disease virus].morphology and chromosomes of cell sublines derived from two new bovine kidney lines are reported. cell susceptibility to the foot-and-mouth disease virus is discussed. one of the sublines showed epithelial-like cells, while the remainder, elonged fibroblastic-like cells. most of them had a diploid number of chromosomes. from these sublines only one was sensible to the foot-and-mouth disease virus.1979233200
serological comparison of a type sat 2 foot-and-mouth disease virus isolate from sudan with other type sat 2 strains. 1979232850
the challenge of vaccinated pigs with foot-and-mouth disease virus. 1979231356
temperature-sensitive mutants of foot-and-mouth disease virus: the isolation of mutants and observations on their properties and genetic recombination.a number of temperature-sensitive mutants were isolated from two strains of foot-and-mouth disease virus (fmdv). various properties of the mutants were examined including comparative growth curves at permissive and restrictive temperatures, cut-off temperatures, thermal lability and ph sensitivity. recombination was observed between various pairs of mutants of fmdv strain pacheco. it occurred early in the growth cycle and the proportion of recombinants remained constant thereafter. maximum recom ...1975237977
factorial experimental design applied to the immunological study of two foot-and-mouth disease virus subtypes. 1. a greece 1969 -- a allier example.a double immunological cross-test, carried out with the index k method, is subjected to a statistical analysis by a factorial experiment. the a greece and a allier viruses, which have been taken as an example of the calculations procedure, seem to be in 2 immunologically different subtypes.1979231923
the nucleotide sequence at the 5' end of foot and mouth disease virus rna.foot and mouth disease virus rna has been treated with rnase h in the presence of oligo (dg) specifically to digest the poly(c) tract which lies near the 5' end of the molecule (10). the short (s) fragment containing the 5' end of the rna was separated from the remainder of the rna (l fragment) by gel electrophoresis. rna ligase mediated labelling of the 3' end of s fragment showed that the rnase h digestion gave rise to molecules that differed only in the number of cytidylic acid residues remai ...1979231762
[protective effect in the serum of rabbits inoculated with bhk-21 cells infected with foot-and-mouth disease virus].the present investigation was developed to determine the presence of protecting effects in the serum of rabbits inoculated with bhk 21 cells infected with foot-and-mouth disease virus, subtype c2. the rabbits received 252 mg. of antigens harvested 60, 65, 75, 90, 120 and 210 minutes post infection. these antigens were inactivated with two procedure: formaldehyde 0.015% and beta-propiolactone 0.2% and were inyected with incomplete freund's adjuvant; the last inoculations were given with live anti ...1979231797
[subtypes of foot-and-mouth disease virus type a. genetic markers of clones obtained from 4 strains isolated in argentina between 1961 and 1970].the results obtained studying the genetic markers g, t and rtc of different clones of subtypes of foot-and-mouth disease virus type a are presented in this paper. the subtypes were isolated during outbreaks of foot and mouth disease in argentine. no significative differences among the subtypes were observed with the t marker. for the other markers, the results seem to indicate a gradual change related with the serological variation. because of their sensibility to guanidine hidrochloride, it is ...1979231800
factorial experimental design applied to the immunological study of two foot-and-mouth disease virus subtypes. 2. theoretical study of experimental models.a certain number of theoretical models of immunological relations that 2 foot-and-mouth disease viruses can support, were constructed so as to discuss in each case, the results of the factorial analysis of the data. this method provided a specific answer to each of the questions that were asked in the presence of a test of this kind. the results obtained with several immunological cross-tests comparable to that of the a greece 69-a allier viruses, illustrated most of the theoretical models.1979231920
purification and identification of the rna-dependent rna polymerase of foot-and-mouth disease virus.the rna-dependent rna polymerase induced in bhk 21 cells by infection with foot-and-mouth disease virus has been isolated from the replication complex. it contains a major, virus-coded protein with mol. wt. 56 000 which appears from serological studies and tryptic peptide mapping to be the same as the virus infection associated (via) antigen and the protein p56 found in cells infected with the virus. other virus coded proteins and a host cell protein were present in the partially purified replic ...1979232134
nucleotide sequence of the cdna and the derived amino acid sequence for the major antigenic protein of foot and mouth disease virus, type asia 1 63/72.a 0.9 kb cdna for the foot and mouth disease virus (fmdv) type asia 1 63/72, cloned in the plasmid pur222 by dc/dg tailing method, was expressed into a protein which was immunogenic in guinea pigs and cattle. the protein purified to homogeneity was found to be basic and of 38 kda. a sequence of 879 nucleotides of the inserted cdna was obtained. the nucleotide sequence was 65% gc-rich and was homologous to the gene for vpi of fmdv types a5, oik and c3 to the extent of 35-40%. from the nucleotide ...19921317347
vpg gene amplification correlates with infective particle formation in foot-and-mouth disease virus.in order to analyze the function of vpg amplification in aphthoviruses, we have undertaken the first mutational analysis of the repetitive vpg-coding region using an improved foot-and-mouth disease virus (fmdv) cdna clone from which infective viral rna was synthesized. a set of vpg mutants was constructed by site-directed mutagenesis which includes different vpg deletion mutations, a vpg insertion mutation, and amino acid residue replacement mutations that interfere with binding of the vpg prote ...19921312630
a comparative chemical and serological study of the full and empty particles of foot-and mouth disease virus.the chemical and serological properties of the full, naturally occurring empty and artificially produced empty particles of foot-and-mouth disease virus, serotype a(subtype 10, strain 16) have been studies. the full 146s particles comprised the virus rna, three polypeptides (vp1 to vp3) mol. wt. about 30 x 10-3, one polypeptide (vp4) mol. wt. about 13-5 x 10-3, and a small amount of a polypeptide (vpo) mol. wt. about 43 x 10-3. the naturally occurring 75s empty particles contained no rna and muc ...1975235596
foot-and-mouth disease virus immunogenic capsid protein vpt: n-terminal sequences and immunogenic peptides obtained by cnbr and tryptic cleavages.the immunogenic capsid protein (vpt), circa 30 kiladaltons (kd), of foot-and-mouth disease virus was examined for (i) its ability to induce neutralizing antibody in guinea pigs after chemical modifications and cnbr or tryptic cleavages and (ii) n-terminal amino sequence homology across three virus types. the immunogenicity of vpt was inactivated by glutaraldehyde treatment, carboxymethylation and maleylation or citraconylation. however, de-citraconylation restored part of the lost activity. clea ...1979231585
maturation of functional antibody affinity in animals immunised with synthetic foot-and-mouth disease virus.a good correlation exists between specific neutralising antibody titre and protection against challenge with foot-and-mouth disease virus (fmdv) in infected or virus-vaccinated cattle, but not in the case of animals immunised with synthetic fmdv peptides. therefore, mechanisms other than simple neutralisation are likely to be important in vivo. antibody affinity may influence the protective capacity of sera from immunised animals and experiments were carried out to measure the functional affinit ...19921316628
crystallization and preliminary x-ray analysis of three serotypes of foot-and-mouth disease virus.foot-and-mouth disease viruses from serotypes o, a and c have been crystallized. the particular strains studied include o1k, a10(61), a22 iraq 24/64, a24 cruzeiro and c-s8c1. in addition, crystals have been grown of g67, a monoclonal antibody neutralization escape mutant derived from o1k, and of virus r100, recovered after the establishment of a persistent infection in baby hamster kidney cells with c-s8c1. empty particles, capsids which lack the rna genome, have also been crystallized for subty ...19921335517
the nucleotide sequences of wild-type coxsackievirus a9 strains imply that an rgd motif in vp1 is functionally significant.we have shown previously that, compared to other enteroviruses, the coxsackievirus a9 (cav-9) prototype strain, griggs, contains a c-terminal extension to the capsid protein vp1 and that within this extension there is an rgd (arginine-glycine-aspartic acid) motif. to determine whether these features are found in other cav-9 strains and therefore analyse whether they are likely to be functionally important, we have determined the nucleotide sequence of the appropriate region from five strains, is ...19921312121
the immune response against foot-and-mouth disease virus: influence of the t lymphocyte growth factors il-1 and il-2 on the murine humoral response in vivo.recombinant and pure "natural" il-1 and il-2 were compared with the muramyl dipeptide (mdp) component of freund's adjuvant for their capacity to enhance the humoral immune response against foot-and-mouth disease (fmd) virus antigen. using a dose of this antigen which alone did not give a detectable immune response, anti-fmd virus antibody was measured at 14 and 28 days post-vaccination. although il-1 could enhance the response against the virus antigen, in particular when administered 24 h befor ...19921312510
a comparison of type o foot and mouth disease virus field isolates from northern thailand.a survey of type o foot and mouth disease (fmd) virus isolates from northern thailand was undertaken to determine the relationship between field viruses and the vaccine in use, and to gauge the range of antigenic variation among field viruses. isolates were collected from the two most recent epizootics, 1986-1987 and 1989-1990, and assessed using a two-dimensional neutralisation test to determine their relationship to fmd type o1 bangkok 1960 (o bkk/60) reference (vaccine challenge) virus. the c ...19921335305
extensive antigenic diversification of foot-and-mouth disease virus by amino acid substitutions outside the major antigenic site.the antigenic sites a and c (the g-h loop and the c terminus, respectively) in vp1 of foot-and-mouth disease virus (fmdv) have been considered the immunodominant regions of the virus involved in the induction of protection. other antigenic sites have been described but their involvement in protection has not been established. here we report that two closely related but serologically different fmdvs (the field isolate c3 argentina/84 and the vaccine strain c3 resende br/55) have identical a and c ...19921335031
identification and characterization of foot-and-mouth disease virus o1 burgwedel/1987 as an intertypic recombinant.the foot-and-mouth disease virus field isolate burgwedel/1987 subtype o1 was found to differ genetically from the antigenically related strain o1 kaufbeuren within the region encoding the non-structural proteins. this genetic difference was indicated by the rnase mismatch cleavage method and confirmed by nucleotide sequencing. an alignment of sequences encoding proteinase 3c of the burgwedel isolate and several other virus strains identified this isolate as an intertypic recombinant; the parent ...19921312120
foot-and-mouth disease: detection of antibodies in cattle sera by blocking elisa.a blocking elisa was developed for the detection of antibodies to foot-and-mouth disease virus sat1, sat2 and sat3 and for the quantification of antibodies on a single dilution of serum. the avidin-biotin system was used. the test was compared with the liquid-phase elisa executed at the world reference laboratory for foot-and-mouth disease. it was found to have favourable logistics and combined high specificity with high sensitivity. the quantitative test using a single dilution of serum was res ...19921333673
theoretical study about the variability of the genome of foot-and-mouth disease viruses.1. the possibilities of change in amino acids of a protein are discussed in terms of a point mutation. 2. whereas met and trp are forced to change due to a point mutation, other amino acids (ala, arg, gly, leu, pro and val) have a probability of 1/3 to survive in the sequence. 3. on basis of these considerations, the genome from 5 strains (csp, c3ind, o1k, a10 and a12) of the foot-and-mouth disease virus was studied. 4. a hypothetical genealogic tree for these strains is suggested, where csp and ...19921310291
comparison between in vitro neutralization titres and in vivo protection against homologous and heterologous challenge induced by vaccines prepared from two serologically distinct variants of foot-and-mouth disease virus, serotype a22.guinea-pigs were challenged with homologous or heterologous strains of foot-and-mouth disease virus (fmdv) following vaccination with baby hamster kidney (bhk) monolayer cell-adapted or bhk suspension cell-adapted strains of fmdv serotype a22 iraq 24/64. the protection afforded by these vaccines was analysed as a function of antigen dose and the in vitro serum virus neutralization titres achieved. the results show that the level of neutralizing antibody induced that afforded 50% protection was s ...19921312129
genetic relationships between southern african sat-2 isolates of foot-and-mouth-disease virus.sequencing of part of the 1d gene of foot-and-mouth disease virus was used to determine the relationships between sat-2 viruses isolated from outbreaks which occurred in cattle in zimbabwe and namibia and in impala in south africa between 1979 and 1989. the results demonstrated that the outbreaks in different countries were unrelated. surprisingly close relationships were shown between all sat-2 viruses isolated from cattle in zimbabwe since 1983 but the two major epizootics which occurred in 19 ...19921334842
evolution of the capsid protein genes of foot-and-mouth disease virus: antigenic variation without accumulation of amino acid substitutions over six decades.the genetic diversification of foot-and-mouth disease virus (fmdv) of serotype c over a 6-decade period was studied by comparing nucleotide sequences of the capsid protein-coding regions of viruses isolated in europe, south america, and the philippines. phylogenetic trees were derived for vp1 and p1 (vp1, vp2, vp3, and vp4) rnas by using the least-squares method. confidence intervals of the derived phylogeny (significance levels of nodes and standard deviations of branch lengths) were placed by ...19921316467
modifications of the 5' untranslated region of foot-and-mouth disease virus after prolonged persistence in cell culture.the nucleotide sequence of the 5'-untranslated region (5'utr) of the genome of foot-and-mouth disease virus (fmdv) r100, rescued after 100 passages of persistently infected bhk-21 cells, has been compared with that of the parental fmdv c-s8c1. the nucleotide sequence divergence between the two viruses in heteropolymeric regions is 1%. the few mutations located at the 5'-most terminal region (s fragment) and at the internal ribosome entry site (ires) do not appear to affect significantly the tigh ...19921335672
a comparative study on the immune response of sheep to foot and mouth disease virus vaccine type asia-1 prepared with different inactivants and adjuvants.foot and mouth disease virus type asia-1 was inactivated either with formaldehyde or binaryethylenimine (bei). inactivated vaccines were prepared incorporating aluminium hydroxide gel or mineral oil as an adjuvant. the antibody response to the adult sheep was studied by elisa and sn test for a period of 6 months. there was no difference in the antibody response between vaccines inactivated with formaldehyde or bei. whereas significant difference in the antibody response was observed between gel ...19921314158
dependence of the adenovirus tripartite leader on the p220 subunit of eukaryotic initiation factor 4f during in vitro translation. effect of p220 cleavage by foot-and-mouth-disease-virus l-protease on in vitro translation.the adenovirus tripartite leader (tpt) 5' untranslated region (5'utr) allows translation in poliovirus-infected cells, in which the p220 subunit of eukaryotic initiation factor 4f is degraded. this p220-independent translation was investigated by measuring in vitro translation in a reticulocyte lysate of a reporter gene, chloramphenicol acetyltransferase, coupled to the tpt 5'utr. the p220 subunit was degraded by translation of a foot-and-mouth-disease l-protease construct. surprisingly, the tpt ...19921321714
heterotypic lymphoproliferative response in pigs vaccinated with foot-and-mouth disease virus. involvement of isolated capsid proteins.the in vitro viral lymphoproliferative response of pigs vaccinated against foot-and-mouth disease virus (fmdv) has been characterized. peripheral blood mononuclear cells from immunized animals up to 1 year post-immunization (p.i.) showed a time-dependent fmdv-specific response, as assayed by virus-specific cellular blastogenesis. the optimum viral concentration decreased with time (around 20 weeks p.i.), and the response was faster and weaker. lymphoproliferation appeared to be mainly due to cd4 ...19921328475
foot-and-mouth disease virus populations are quasispecies. 19921318185
primer design for specific diagnosis by pcr of highly variable rna viruses: typing of foot-and-mouth disease virus.a pcr assay for the specific detection and identification of viral sequences that correlate with established serotypes of foot-and-mouth disease virus (fmdv) has been developed. a new analysis based on homology profiles among reported sequences was used for primer design. rna replicase (3d) gene regions that showed high homology among fmdvs, and low homology to other picornaviruses, were used for pcr amplification. specific and highly sensitive detection was achieved for rna of fmdv types c, a, ...19921318612
maintenance of foot and mouth disease viruses in buffalo (syncerus caffer sparrman, 1779) in southern africa.using age-related infection rates derived from serological data in available deterministic and specially developed stochastic simulation models, it has been possible to establish that the basic reproductive rates for south african territory (sat) type foot and mouth disease virus in buffalo (syncerus caffer) are high. the models predict that there is a periodicity of infection within herds and possibly the population as a whole. thus, buffalo herds are likely to be more infectious at some times ...19921339066
detection of fmdv rna amplified by the polymerase chain reaction (pcr).molecular detection of foot-and-mouth disease virus (fmdv) using the polymerase chain reaction (pcr) is a rapid and accurate method. in this study we present pcr for the detection of fmdv rna in infected bhk cells. using pcr and two primers selected from the rna polymerase gene, a conserved sequence in all types and subtypes of fmdv, we were able to detect fmdv rna present in rna extracted from the fmdv-infected cells. rna from uninfected bhk cells gave negative results. another set of primers s ...19921313822
antiviral effects of a thiol protease inhibitor on foot-and-mouth disease virus.the thiol protease inhibitor e-64 specifically blocks autocatalytic activity of the leader protease of foot-and-mouth disease virus (fmdv) and interferes with cleavage of the structural protein precursor in an in vitro translation assay programmed with virion rna. experiments with fmdv-infected cells and e-64 or a membrane-permeable analog, e-64d, have confirmed these results and demonstrated interference in virus assembly, causing a reduction in virus yield. in addition, there is a lag in the a ...19921331517
[the electrophysiological properties of the structural polypeptides of the foot-and-mouth-disease virus].the methodological approaches of isolation of preparations of fmdv structural polypeptides to analyse them by the electrophoresis and electro-focussing methods are presented. the value of isoelectric points of protein coat of fmdv structural polypeptides and corresponding them values of electric potential are determined. the similarity and differences of fmdv serotypes, characterized by the value of relative surface, falling on separate polypeptides, are determined for the virion structure on th ...19921338893
does the vp1 gene of foot-and-mouth disease virus behave as a molecular clock?we have carried out a phylogenetic study of the evolution of the vp1 gene sequence from different serological types and subtypes of foot-and-mouth disease virus (fmdv). the maximum-likelihood method developed by hasegawa and co-workers (hasegawa et al. 1985) for the estimation of evolutionary parameters and branching dates has been used to decide between alternative models of evolution: constant versus variable rates. the results obtained indicate that a constant rate model, i.e., a molecular cl ...19921325567
dual initiation sites of protein synthesis on foot-and-mouth disease virus rna are selected following internal entry and scanning of ribosomes in vivo.the initiation of protein synthesis on foot-and-mouth disease virus rna occurs at two sites separated by 84 nucleotides. immediately upstream from the first of these sites is the internal ribosome entry site (ires), which directs the translation of this rna to be cap-independent. the utilization of these two initiation sites has been examined using artificial fusion genes in vivo under a variety of conditions. additional in-frame aug codons have been introduced between these two authentic start ...19921339342
a mechanism involved in the plaque enhancement effect of sodium thiosulfate for foot-and-mouth disease viruses.a mechanism involved in the plaque enhancement effect of foot-and-mouth disease viruses (fmdv) by the addition of sodium thiosulfate (hypo) in the agar overlay medium (aom) previously reported was studied. it was experimentally proved that the diffusion of virus particles through agar overlay medium was enhanced when this salt was incorporated. accordingly, the enlarged plaque formation was assumed to be caused by the enhanced diffusion of viral progenies produced in infectious centers during pl ...19921331716
[comparison of various methods for the measurement of the humoral immune response in mice vaccinated with aphthous fever virus].kinetics of the humoral immune primary response and seven-day secondary response of adult cf1 mice to fmdv o1 campos adjuvanted in aluminium hydroxide-saponin (ahs) or in oil emulsion (oe) were evaluated by means of elisa and passive hemagglutination (ph). analysis of the response to ahs vaccine showed that elisa measured maximal titres of primary response at 23 days post-vaccination (dpv), and at day 17 of secondary response, while ph detected maximal titres for primary as well as secondary res ...19921338879
foot-and-mouth disease virus typing by complement fixation and enzyme-linked immunosorbent assay using monovalent and polyvalent antisera.an indirect "sandwich" enzyme-linked immunosorbent assay (elisa) using polyvalent and monovalent antisera was compared with the 50% complement fixation (cf50) test for the detection of foot-and-mouth disease (fmd) o, a, and c virus types. elisa was more sensitive than cf50 tests when polyvalent antisera were used for detecting the 3 types of virus in epithelial samples, whereas elisa using monovalent antisera was the least sensitive technique. the elisa performed with polyvalent antisera was 9 t ...19921325192
a pathogenesis study of foot-and-mouth disease in cattle, using in situ hybridization.eight calves were exposed in an aerosol chamber to nebulized foot-and-mouth disease virus. two control animals were exposed in a similar manner to cell culture media only. animals were euthanized at intervals and various tissues examined by in situ hybridization using a biotinylated rna probe corresponding to a portion of the viral gene coding for the polymerase enzyme. by this technique large amounts of viral nucleic acid were found in coronary band, interdigital cleft and tongue as early as si ...19921330277
expression in yeast of amino-terminal peptide fusions to hepatitis b core antigen and their immunological properties.hepatitis b core protein (hbcag) is a potent antigen that gives both a t-cell-dependent and a t-cell-independent antibody response. it has been shown that a foreign epitope can be fused to the amino terminus of hbcag without affecting particle integrity, and that the resulting chimaeric cores retain the immunogenicity of the foreign epitope. here we describe the efficient expression in yeast of two different chimaeric cores, carrying epitopes of foot and mouth disease virus (fmdv) or human chori ...19901369994
conformational study of a nine residue fragment of the antigenic loop of foot-and-mouth disease virus.the nine-residue peptide ac-tasargdla-nhme was selected as model peptide in order to understand the conformational features of the antigenic loop of foot-and-mouth disease virus (fmdv). a throughout exploration of the conformational space has been carried out by means of molecular dynamics (md) and energy minimization. the calculations have been carried out using the amber force field. solvent effects have been included by an effective dielectric constant of epsilon = 4r. the lowest energy confo ...19921329841
the application of biotechnology to the control of foot-and-mouth disease virus.biotechnology, which less than 10 years ago was heralded as an alternative to epidemiology in providing the answers to the control of foot-and-mouth disease (fmd), has not fulfilled its initial promise. instead it is now complementing epidemiology by providing extremely sensitive and specific tools for identifying and characterizing strains of fmd virus in diagnostic material. considerable advances in our understanding of the evolution of the virus in different field situations has been made pos ...19921330200
molecular cloning and expression of the vp1 gene of foot-and-mouth disease virus c1 in e. coli: effect on bacterial cell viability.the vp1 gene of foot-and-mouth disease virus (serotype c1) has been cloned in escherichia coli clts cells, under the control of the bacteriophage lambda pl promoter. the expressed vp1 protein was complete and non-fused, and its molecular weight was indistinguishable from that of the vp1 obtained from virions. cells harbouring the recombinant vectors exhibited symptoms of plasmid instability and toxicity and died in a few weeks even when never exposed to inducing conditions. a new plasmid clone i ...19911369359
maximizing the expression of a recombinant gene in escherichia coli by manipulation of induction time using lactose as inducer.the use of isopropyl-beta-d-thiogalactoside (iptg) for induction of the lac-promoter in small-scale cultivations is well established. however, for large-scale microbiological processes the cost of this inducer is a severe limitation. here is described a method by which lactose is used as inducer of the lac promoter with the same efficiency as that of iptg. it was found that after growth on glucose the time of the addition of lactose is important for the quality of induction. the resulting yield ...19921369364
foot-and-mouth disease virus c3 resende subtype analysed by means of competition ria using neutralizing monoclonal antibodies.foot-and-mouth disease virus (fmdv) was analysed using 30 monoclonal antibodies (mabs) obtained from balb/c mice immunized with fmdv c3 resende (c3r) subtype 7 and 14 days before fusion no. 15 and 16 respectively. fourteen mabs were neutralizing and by means of competition radioimmuno assay it was possible to classify them into four groups. the first group consisted of mabs specific for three sequential and three conformational epitopes. the second group consisted of mabs specific for two confor ...19921379398
changes in mononuclear peripheral blood cells in cattle with foot-and-mouth disease.the percentages and absolute numbers of mononuclear peripheral blood cells (mnc) were studied in vaccinated (vac) and non-vaccinated (control) cattle, challenged with foot-and-mouth disease virus (fmdv). all vac cattle but none of the controls resisted challenge. cell populations were studied immediately before and one week after challenge, by direct and indirect immunofluorescence, using polyclonal and monoclonal antibodies against different bovine markers. total b-lymphocytes, as assessed with ...19921347666
the n-terminal amino acid sequence is essential for foot-and-mouth disease virus replicase activity.1. foot-and-mouth disease virus replicase was expressed by fusing its cdna to the ompa signal peptide coding sequence present in the pin-iii ompa series vectors. 2. two constructions were developed to express either a full-length or truncated enzyme lacking the 20 amino acids at the n-terminal end. bacterial extracts expressing the recombinant proteins were submitted to sds-page and the presence of the replicase was revealed by immunoblotting. the truncated form exhibited a higher mobility and t ...19921342596
fitness alteration of foot-and-mouth disease virus mutants: measurement of adaptability of viral quasispecies.we document the rapid alteration of fitness of two foot-and-mouth disease virus (fmdv) mutants resistant to a neutralizing monoclonal antibody. both mutants showed a selective disadvantage in bhk-21 cells when passaged in competition with their parental fmdv. upon repeated replication of the mutants alone, they acquired a selective advantage over the parental fmdv and fixed additional genomic substitutions without reversion of the monoclonal antibody-resistant phenotype. thus, variants that were ...19911645804
in vitro activities of a recombinant foot-and-mouth disease virus replicase expressed in escherichia coli.1. the replicase gene of foot-and-mouth disease virus (fmdv) was expressed in escherichia coli under the control of a tac promoter. the recombinant enzyme was purified by inclusion body precipitation, elution, and poly(u) sepharose chromatography. 2. the enzyme exhibits poly(a)-dependent oligo(u)-primed poly(u) polymerase activity. the specific activity of the purified replicase is 1.3 x 10(5). the recombinant replicase synthesizes rna using fmdv rna as template, as well as heterologous rnas, su ...19921342607
antigenic stability of foot-and-mouth disease virus variants on serial passage in cell culture.two neutralizing monoclonal antibody (mab)-resistant variants selected from an isolate of foot-and-mouth disease virus (fmdv) type a5 were repeatedly passaged in cell culture and monitored for susceptibility to neutralization by the selecting mab. a variant isolated with a mab to a conformational epitope (1-og2) lost resistance in 20 passages, while a variant isolated with a mab to a linear epitope (1-ha6) persisted for 30 passages. in both cases, the virus population emerging after passage was ...19911645803
proliferative lymphocyte responses to foot-and-mouth disease virus and three fmdv peptides after vaccination or immunization with these peptides in cattle.we studied proliferative responses of bovine t lymphocytes to foot-and-mouth disease virus (fmdv) serotypes a, o and c as well as to three peptides including the two major b-cell epitopes of fmdv (vp1[141-156] and vp1[200-213]). peripheral blood mononuclear cells (pbmc) from cattle previously vaccinated with monovalent vaccine responded to both homotypic and heterotypic virus strains. of 14 fmdv-specific bovine t-cell clones, which were prepared from pbmc of an animal vaccinated with the trivale ...19921349300
cross-reactive and serotype-specific antibodies against foot-and-mouth disease virus generated by different regions of the same synthetic peptide.synthetic peptides based on the vp1 proteins of two serotypes of foot-and-mouth disease virus (fmdv) and having the general formula c-c-(200-213)-p-p-s-(141-158)-p-c-g induce heterologous as well as homologous protection against challenge. substitution of the sequence consisting of residues 200 to 213 (200-213 sequence) with a second copy of the homologous 141-158 sequence (i.e., homodimers) resulted in failure of either serotype peptide to protect heterologously. the antiviral and antipeptide t ...19921372368
modulation of t-cell reactivity to synthetic peptide analogues of foot-and-mouth disease virus in sheep by amino acid substitutions.the ability of synthetic peptide analogues of foot-and-mouth disease virus vp1 capsid protein to induce t-cell proliferation in vitro following immunization of sheep with the uncoupled peptides was assessed. elevated t-cell responses were obtained to a 21-residue peptide containing vp1 residues 141-158, and a 40-residue peptide containing residues 200-213 and 141-158 linked via a diproline-serine spacer. in contrast, no significant t-cell response was obtained with a 19-residue peptide containin ...19921375405
a study on the immune response of sheep to foot and mouth disease virus vaccine type 'o' prepared with different inactivants and adjuvants.foot and mouth disease virus (fmdv) type 'o' was inactivated either with formaldehyde or binaryethyleneimine (bei). vaccines were prepared with inactivated virus incorporating aluminum hydroxide gel or mineral oil as an adjuvant. the antibody response in sheep was monitored by serum neutralization and elisa test for a period of six months. significant difference in antibody response was not observed between vaccines inactivated with formaldehyde or bei. on the other hand significant difference i ...19921364024
modification of foot-and-mouth disease virus o1 caseros after serial passages in the presence of antiviral polyclonal sera.foot-and-mouth disease virus (fmdv) shows a remarkable antigenic variability and, like other rna viruses, presents a high rate of mutation. it has been proposed that selection exerted by antibodies of the host could play a major role in the rapid evolution of fmdv. the present work reports the selection of fmdv antibody-resistant (nr) populations after serial passages of a cloned fmdv o1 caseros strain on secondary monolayers of bovine kidney cells in the presence of subneutralizing antiviral po ...19921374806
foot-and-mouth disease virus o1lombardy is biochemically related to o2 isolates.the capsid protein vp1-encoding rna regions of the foot-and-mouth disease virus isolates o1lombardy/1946 and o2brescia/1947 were sequenced and found to be closely related to each other and to o2normandy/1949, despite some sequence differences. the o1lombardy sequence was expected to be more closely related to those of the subtype o1 isolates of 1965 and later (e.g., o1kaufbeuren/1966), but this was not the case. the serological subtyping of both the lombardy and the kaufbeuren isolate as o1 stra ...19911663294
fixation of mutations at the vp1 gene of foot-and-mouth disease virus. can quasispecies define a transient molecular clock?the number of nucleotide (nt) substitutions found in the vp1 gene (encoding viral capsid protein) between any two of 16 closely related isolates of foot-and-mouth disease virus (fmdv) has been quantified as a function of the time interval between isolations [villaverde et al., j. mol. biol. 204 (1988) 771-776]. one of them (isolate c-s12) includes some replacements found in isolates that preceded it and other replacements found in later isolates. the study has revealed alternating periods of rap ...19911653754
correlations between the conformations elucidated by cd spectroscopy and the antigenic properties of four peptides of the foot-and-mouth disease virus.the conformational features of four related antigenic peptides (a, b, c and usa) from the foot-and-mouth disease virus (fmdv) (vp1; 141-160 of serotype a, subtype 12), assessed by cd, were found to correlate with the serological properties of these peptides. the cd spectra of the four peptides, obtained under cryogenic and solvent titration conditions, were consistent with three conformational components (a left-handed extended helix, an alpha-helix and a 3(10) helix) for peptides a and c and fo ...19911651235
characterization and immune response of a protein produced by a cdna clone of foot and mouth disease virus, type asia 1 63/72.a 0.9 kb double stranded cdna of foot and mouth disease virus (fmdv) type asia 1, 63/72 was cloned in an expression vector, pur222. a protein of 38 kd was produced by the clone which reacted with the antibodies raised against the virus. a 20 kd protein which may be derived from the 38 kd protein contained the antigenic epitopes of the protein vp1 of the virus. injection of 10-20 micrograms of the partially purified 38 and 20 kd proteins or a lysate of cells containing 240 micrograms of the prote ...19921378734
interaction of a cellular 57-kilodalton protein with the internal translation initiation site of foot-and-mouth disease virus.a cellular 57-kda protein (p57) that binds specifically to the internal translation initiation site in the 5' untranslated region of foot-and-mouth disease virus rna was detected in cell extracts of different mammalian species by uv cross-linking. the protein binds to two distinct sites of the translation control region which have as the only common sequence a uuuc motif. the first binding site consists of a conserved hairpin structure, whereas the second binding site contains an essential pyrim ...19911658355
non-additive effects of multiple amino acid substitutions on antigen-antibody recognition.synthetic peptides have been used to mimic the main antigenic site of foot-and-mouth disease virus (fmdv) of serotype c and of several variant isolates. this region includes multiple continuous b cell epitopes. the effect of single amino acid replacements, individually or in combination, on antigen specificity has been evaluated using monoclonal antibodies. quantitative enzyme immunodot assays have shown that both additive and non-additive effects of multiple replacements occur in continuous b c ...19921376255
the capsid protein-encoding sequence of foot-and-mouth disease virus o2brescia.nucleotide sequences encoding the four capsid proteins of foot-and-mouth disease virus subtype o2brescia/1947 have been determined. these and the deduced amino acid sequences were compared with those of a subtype o1 virus strain. the nucleotide sequences differed at 259 positions, causing only 35 amino acid changes. vp4 and vp2 differed by 2.4 and 1.8%, whereas vp1, known as major viral antigen, and vp3 differed by 8% and 5.5%, respectively. the differences occur mainly in protein domains not in ...19911656918
expression, processing, and assembly of foot-and-mouth disease virus capsid structures in heterologous systems: induction of a neutralizing antibody response in guinea pigs.plasmids containing the foot-and-mouth disease virus structural protein precursor (p1) and 3c protease genes or the p1 gene alone were expressed in escherichia coli. a recombinant baculovirus containing the p1 gene was also generated and expressed in spodoptera frugiperda cells. expression of the p1 and 3c genes in e. coli resulted in efficient synthesis and processing of the structural protein precursor and assembly into 70s empty capsids. this material reacted with neutralizing monoclonal anti ...19911658362
comparison of the immune response elicited by infectious and inactivated foot-and-mouth disease virus in mice.the immune response to foot-and-mouth disease virus (fmdv) elicited by infection or immunization with inactivated virus in adult mice was examined. a model of adoptive transfer of immunocompetent cells was used for this purpose. the results presented here indicate that both short- and long-term secondary immune responses elicited by high doses of inactivated virus are indistinguishable, at the humoral or cellular level, from that observed after infection. the responses to inactivated or infectio ...19911649903
rapid and sensitive detection of foot-and-mouth disease virus in tissues by enzymatic rna amplification of the polymerase gene.direct detection of foot-and-mouth disease (fmd) virus from infected bovine and porcine tissue was investigated using a modified polymerase chain reaction (pcr) technique. a high degree of conservation was found in the genomic region coding for the viral rna polymerase among the seven fmd viral (fmdv) serotypes. an oligomeric primer pair and probe were constructed from consensus sequence data within this area. first strand cdna was synthesized using random hexamers and moloney mulv reverse trans ...19911666635
a preliminary study of the pathogenesis of foot-and-mouth disease virus using in situ hybridization.five adult guinea pigs were inoculated intraepithelially in the right hindfoot pad with foot-and-mouth disease virus. animals were euthanatized with carbon dioxide at 4, 10, 24, 48, and 72 hours post-inoculation. generalized disease developed in the guinea pigs, as evidenced by depression and inappetance by 24 hours post-inoculation and by the formation of vesicles in the noninoculated hindfoot pad by 48 hours post-inoculation. by in situ hybridization, using a 500 base pair biotinylated rna pro ...19911650051
two mechanisms of antigenic diversification of foot-and-mouth disease virus.the amino acid replacements that underlay the diversification of the main antigenic site a (vp1 residues 138 to 150) of foot-and-mouth disease virus (fmdv) of serotype c have been identified. sixteen new vp1 sequences of isolates from 1926 until 1989 belonging to subtypes c1, c2, c3, c4, c5, and unclassified are reported. the reactivities in enzyme-linked immunoelectrotransfer blot assays of capsid protein vp1 with a panel of neutralizing monoclonal antibodies that recognize sites a or c (the vp ...19911653494
the detection of antibodies against foot-and-mouth disease virus (fmdv) in filter paper eluates from pig sera or whole blood by elisa.the use of pig blood samples dried on paper discs for the detection of antibodies against fmdv by the liquid phase blocking elisa has been evaluated. the average volume of whole heparinised blood required to fully saturate 6.0 mm discs was 7.65 microliters (range 7.2 to 8.1; variation = 0.24, p = 0.05). when 200 clinically healthy animals were assessed by virus neutralisation (vn) titres up to 1/22 were recorded against types o, a and c, 97% being 1/11 or less. using elisa, results were more ske ...19911666636
generation of a subtype-specific neutralization epitope in foot-and-mouth disease virus of a different subtype.an epitope involved in neutralization of foot-and-mouth disease virus (fmdv) of subtype c3 was generated by a single amino acid replacement in vp1 of fmdv of subtype c1. the replacement [ser (139)----ile, in the immunodominant site a] was consistently found in those fmdv c1 santa pau-sp/70 mutants resistant to neutralization by monoclonal antibody (mab) sd6 (specific for most c1 viruses) that acquired the capacity to be neutralized by mab 7ab5 (specific for c3 viruses).19921370534
antigenic relationships of foot-and-mouth disease virus serotype asia-1 isolates demonstrated by monoclonal antibodies.a panel (26) of monoclonal antibodies (mabs) was elicited against three distinct isolates of foot-and-mouth disease virus (fmdv) serotype asia-1. each mab was characterized according to the location of its epitope: class i, restricted to the intact virion (140s); class ii, restricted to 140s and the virion protein subunit (12sps); class iii, available on 140s, 12sps and virus protein 1; class iv, restricted to 12sps. in addition, the mabs were further categorized by isotype, neutralization of vi ...19921375792
enhancement of the immune response elicited with foot-and-mouth disease virus vaccines by an extract of the mycobacterium sp. wall.the immunomodulating effect of an extract of the cell wall of mycobacterium sp. (wsf, vetrepharm inc., london, canada) in foot-and-mouth disease virus inactivated vaccines was tested in a murine model. the duration of immunity, protection, stimulation of immunocompetent cells acting on the long-lasting secondary response and possible tissue damage were examined. the incorporation of 10 micrograms wsf into aqueous and oil vaccines induced a high and long-lasting specific antibody response. the ne ...19911667346
[primary structure of the gene for protein vp1 from foot-and-mouth disease virus serotype o1 isolated in the ussr].the nucleotides sequence has been determined for the viral rna and some of its cdnas coding for the major antigenic protein of the epidemic stomatitis o1-194 and o1-1618 vp1 viruses. the expressed microheterogeneity has been registered for the population of the strain o1-194.19901694961
cleavage of foot-and-mouth disease virus polyprotein is mediated by residues located within a 19 amino acid sequence.the 2a region of the foot-and-mouth disease virus (fmdv) polyprotein is only 16 amino acids in length. during synthesis of the fmdv polyprotein a primary proteolytic processing event occurs between the 2a and 2b regions of the polyprotein. the activity responsible for this cleavage is not known but it is thought that either an unidentified virus-encoded proteinase may be responsible, or that 2a acts as a substrate for a host cell proteinase. a series of recombinant fmdv polyproteins has been con ...19911658199
comparison of the 5' and 3' untranslated genomic regions of virulent and attenuated foot-and-mouth disease viruses (strains o1 campos and c3 resende).the complete 5' and 3' non-coding regions of two attenuated south american foot-and-mouth disease virus (fmdv) vaccine strains, o1c-o/e and c3r-o/e, and their corresponding virulent parental strains, o1 campos and c3 resende, have been cloned from polymerase chain reaction-amplified primary cdna. differences observed in the derived nucleotide sequences between attenuated and virulent viruses seem not to affect regulatory signal structures, supporting the theory that genetic variations, primarily ...19911658210
immunological evaluation of the multiple antigen peptide (map) system using the major immunogenic site of foot-and-mouth disease virus.the multiple antigenic peptide (map) system for presenting epitopes to the immune system has been studied with an immunogenic foot-and-mouth disease virus (fmdv) peptide comprising amino acids 141-160 of protein vp1. neutralizing antibody responses known to protect guinea-pigs against challenge infection were obtained with a single inoculation of 0.8-4 micrograms of peptide, presented as an octamer or a tetramer, whereas 20 micrograms of a dimer were required to evoke a similar level of antibody ...19911652552
studies on antigenic variability of c strains of foot-and-mouth disease virus by means of synthetic peptides and monoclonal antibodies.peptides representing the sequence of the immunodominant loop of foot-and-mouth disease virus strain c-s8 (ytasargdlahltttharhlp, residues 136-156 of vp1) and of several variant viruses have been prepared by solid phase methods. in addition, five peptides with single-residue replacements at leu147 (ile, nle, val, ala, gly) have been synthesized. tosyl and dinitrophenyl protections for histidine have been compared, the latter being found to give better synthetic products. the peptides have been t ...19921378821
putative papain-related thiol proteases of positive-strand rna viruses. identification of rubi- and aphthovirus proteases and delineation of a novel conserved domain associated with proteases of rubi-, alpha- and coronaviruses.a computer-assisted comparative analysis of the amino acid sequences of (putative) thiol proteases encoded by the genomes of several diverse groups of positive-stranded rna viruses and distantly related to the family of cellular papain-like proteases is presented. a high level of similarity was detected between the leader protease of foot-and-mouth-disease virus and the protease of murine hepatitis coronavirus which cleaves the n-terminal p28 protein from the polyprotein. statistically significa ...19911652473
hepatitis a virus attachment to cultured cell lines.identification of a hepatitis a virus (hav) receptor is important for understanding hav tissue tropism and replication sites and in the design of vaccines and antiviral therapy. the attachment of hav to cultured cell lines was evaluated: calcium-dependent specific attachment of four hav strains to permissive cells occurred, whereas binding to nonpermissive cells did not. investigation of hav antigenic variant strains (neutralization escape mutants) demonstrated identical attachment properties wi ...19911659597
an overview of the inactivation of fmdv and the implications when residual virus is present in vaccines.most foot-and-mouth disease (fmd) vaccines are prepared by inactivating the virus with acetylethyleneimine or binary ethyleneimine. however, formaldehyde is still used by some manufacturers despite the well-documented evidence that inactivation with this reagent is not a linear or first-order reaction. recent german work provides clear evidence that almost all the outbreaks in western europe in recent years have been caused by viruses closely related to strains which were isolated more than 20 y ...19911665462
[detection of neutralizing antibodies in calves after single vaccination against foot-and-mouth disease virus type asia 1 in the field].on june 20th 1984 appeared the first fmd-type asia 1 outbreak in greece. around the outbreak all susceptible animals were vaccinated with asia 1 vaccine produced by iffa mereiux. three weeks after this first vaccination blood samples have been collected and examined for neutralizing antibodies. from 101 examined calves 37 were younger than 6 months, 63 between 6-11 months and one was 12 months old. the titer of the first group was less than 1.2 in 14 and greater than 1.8 in 8 calves. by the seco ...19911659374
[immune response in mice induced by different doses of foot-and-mouth disease virus].response against foot-and-mouth disease virus 01 campos on vaccinated female mice and suckling litter was estimated. vaccine doses ranged between 0.05 and 30 micrograms of virus. the lower dose protected 39.5% of suckling litter whereas 100% protection was achieved using the higher doses. serum neutralization indexes in females, at 45 days post vaccination, ranged from 3.60 to 4.86 for 0.05 microgram to 0.10 microgram and 4.86 to 5.50 for the high doses. although the doses were excessively high ...19911667697
[protection from foot-and-mouth disease virus in naturally-susceptible animals by a linear polymer of a synthetic peptide].linear polymer of a peptide corresponding to the fragment 142-155 of the foot-and-mouth disease virus a22(550) protein (vp1) was synthesized. whereas the monomeric peptide was only slightly immunogenic, the polymer induced virus-neutralizing antibodies in rabbits and protected 100% guinea pigs. sheep vaccinated once and cattle vaccinated twice were stable against infection with the homologous virulent foot-and-mouth disease virus.19911665331
identification of neutralizing antigenic sites on vp1 and vp2 of type a5 foot-and-mouth disease virus, defined by neutralization-resistant variants.five neutralizing monoclonal antibodies (nmabs) obtained against type a5 spain-86 foot-and-mouth disease virus were used to generate a series of neutralization-resistant variants. in vitro and in vivo assays showed that the variants were fully refractory to neutralization by the selecting nmab. on the basis of cross-neutralization and binding assays, two neutralizing antigenic sites have been located on the virus surface; one, located near the c-terminus of vp1, displayed a linear epitope, and t ...19911707983
genetic and phenotypic variability during replication of foot-and-mouth disease virus in swine.a plaque-purified preparation of foot-and-mouth disease virus (fmdv) of serotype c1 (c-s8c1-1), grown in cell culture, was used to infect nonimmunized pigs. no variant genomes were detected in the average populations of 50 viruses isolated from infected animals by direct rna sequencing of the carboxy-terminal half of the vp1 gene. however, a mutant with altered phenotypic properties was present in low proportion in an infected animal. the frequency of mutants resistant to neutralization by sd6 m ...19901700543
freeze-drying foot-and-mouth disease virus antigens. i. infectivity studies.the ability of foot-and-mouth disease virus strains type o1 bfs 1860 and type a22 irq 24/64 to retain infectivity after freeze-drying with or without additives being made to virus suspensions was studied. the infectivity titres of freeze-dried antigens was assessed at intervals over a six month storage period at various temperatures and also after reconstitution to the liquid phase and storage with or without glycerination. certain additive solutions were necessary to prevent degradation of viru ...19901698805
detection and localization of single-base sequence differences in foot-and-mouth disease virus genomes by the rnase mismatch cleavage method.the rnase mismatch cleavage method was examined for its efficiency of indicating single-base sequence differences in the capsid protein-coding regions of different foot-and-mouth disease virus subtype o1 strains. the method was found suitable for indicating such differences. rnase a as well as rnase t1 contributed to substrate conversion. examples for the cleavage of eleven different single-base mismatches in rna double-strands are now known. all virus genomes found to differ from each other exh ...19911664431
expression of an active foot-and-mouth disease virus rna polymerase in escherichia coli.the expression of a native form of the foot-and-mouth disease virus rna polymerase was obtained. two oligonucleotides of 66 base pairs were used to rebuild the 5' end of the gene and to introduce the first methionine codon. the expression of the active polymerase in e. coli was achieved by inserting the gene before the tac promoter of the pkk223-3 plasmid.19911668400
detection of t1-oligonucleotides of the foot-and-mouth disease virus rna [correction of dna] by silver staining.viral (v) rna was isolated from purified foot-and-mouth disease virus (fmdv) by phenol-chloroform-isoamylalcohol treatment, digested by rnase t1 and separated by one-dimensional polyacrylamide gel electrophoresis (page). the oligonucleotides were detected by silver staining. about 45 micrograms of vrna corresponding to about 100 ml of infectious bhk-21 cell culture fluid yielded a pattern of nearly 20 bands sufficient to differentiate between the fmd viruses.19901698016
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