Publications

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).	1992	1370534
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 ...	1990	1369994
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 ...	1992	1369364
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 ...	1991	1369359
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 ...	1992	1364024
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 ...	1992	1349300
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 ...	1992	1347666
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 ...	1992	1342607
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 ...	1992	1342596
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 ...	1992	1339342
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 ...	1992	1339066
[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 ...	1992	1338893
[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 ...	1992	1338879
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 ...	1992	1335672
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 ...	1992	1335517
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 ...	1992	1335305
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 ...	1992	1335031
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 ...	1992	1334842
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 ...	1992	1333673
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 ...	1992	1331716
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 ...	1992	1331517
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 ...	1992	1330277
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 ...	1992	1330200
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 ...	1992	1329841
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 ...	1992	1328475
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 ...	1992	1325567
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 ...	1992	1325192
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 ...	1992	1321714
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, ...	1992	1318612
foot-and-mouth disease virus populations are quasispecies.		1992	1318185
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 ...	1992	1317347
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 ...	1992	1316628
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 ...	1992	1316467
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 ...	1992	1314158
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 ...	1992	1313822
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 ...	1992	1312630
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 ...	1992	1312510
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 ...	1992	1312129
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 ...	1992	1312121
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 ...	1992	1312120
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 ...	1992	1310291
[occurrence of an increased reaction to challenge infection after vaccination with aerosols of inactivated foot-and-mouth disease virus].		1976	961209
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 ...	1975	237977
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 ...	1975	235596
[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 ...	1979	233417
[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.	1979	233200
[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.	1979	233199
serological comparison of a type sat 2 foot-and-mouth disease virus isolate from sudan with other type sat 2 strains.		1979	232850
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 ...	1979	232134
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.	1979	231923
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.	1979	231920
[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 ...	1979	231800
[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 ...	1979	231797
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 ...	1979	231762
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 ...	1979	231585
the challenge of vaccinated pigs with foot-and-mouth disease virus.		1979	231356
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 ...	1979	229806
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.	1979	229792
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 ...	1979	229787
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.	1979	229162
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.	1979	229161
the relation of poly(a) length to specific infectivity of viral rna: a comparison of different types of foot-and-mouth disease virus.		1979	228485
isolation of foot-and-mouth disease virus messenger rna from membrane-bound polyribosomes and characterization of its 5' and 3' termini.		1979	228483
[interaction between foot-and-mouth disease virus and the cells of different chronically infected animals].		1979	228472
antibody response against foot and mouth disease virus (fmdv). part i: responses measured in sera of vaccinated steers with complete virus, trypsin treated virus, 12 s virus subunits and heterologous virus.		1979	225907
morphogenesis of foot-and-mouth disease virus. i. role of procapsids as virion precursors.	the role of procapsids during foot-and-mouth disease virus multiplication was studied on infected bhk-21 cells. purified virus and procapsids were obtained by treating the infected cytoplasmic extracts with rnase and edta. the synthesis of virus, procapsids, and total particles was determined in pulse-chase experiments. a precursor-product relationship between procapsids and virions was obtained. the results show that the rate of synthesis of total particles (virus + procapsids) was linear from ...	1979	225534
isolation and characterization of trypsin-resistant o1 variants of foot-and-mouth disease virus.	strains of foot-and-mouth disease virus of types o1 and a10 were isolated which showed no significant loss of infectivity upon trypsinization. these 'trypsin-resistant' (tr) viruses were obtained by serial passage in bhk cells of virus that was trypsin-treated before inoculation of the cells. three o1 isolates were cloned and studied further. cell attachment of those tr o1 variants (otr1) was not reduced by trypsinization, unlike that of parent virus. the polypeptide compositions of tr viruses a ...	1979	225425
[influence of a hypertonic medium on cell susceptibility to foot-and-mouth disease virus].	the influence of hypertonic medium on the relationship between two cell clones of ib-rs-2 swine line and the foot-and-mouth disease virus was studied. although the number of infected cells was increased by the cell treatment with the hypertonic medium, before or during the time of virus adsorption and penetration onto the cells, showed by the plaque number, the viral replication was partially inhibited as showed by the plaque size as by the viral yield in one-cycle of infection. on the other han ...	1978	224844
[swine cell sublines with different ploidies. iii. susceptibility to foot-and-mouth disease virus].	ib-rs-10-ii subline with tetraploid level cells was more susceptible to the infection by the foot-and-mouth disease virus (fmdv) asq-pg strain than ib-rs-10-i subline with diploid level cells, when number and size of plaques and cytopathogenic effect of the virus were used as criteria. besides, the virus yield in one-cycle of infection was almost the double in ib-rs-10-ii than ib-rs-10-i cell subline and the near-tetraploid cells were more susceptible to be infected by the virus than the near-di ...	1978	224843
[effects of polyionic compounds in the plaque formation of different strains of foot-and-mouth disease virus (fmdv) in the swine cell line ib-rs-2].	the effects of dithylaminoethyl (deae)-dextran (dd) and dextran-sulfate (ds) were studied in some strains of the foot-and-mouth disease virus (fmdv). the strains asq-pg, cr and o, large plaque variants in ib-rs-2 cells, when dd or ds were added to the agar overlay, the plaques were inhibited. however, the strains asq-pp and ci, that are small plaque variants in ib-rs-2 cells, when to the agar overlay was added dd the plaques were greatly enhanced while when was added ds the plaques were inhibite ...	1978	224842
[isolation of foot-and mouth disease virus in swine with other diseases].	the authors took a survey of foot-and-mouth disease samples of myocardium and tonsil from swine which was died without clinicals signs of foot-and-mouth disease, with isolation of virus, type o, a and c. it was observed and accentuated relation between the incidence of hog cholera, pneumonia and atipic foot-and-mouth disease, especially from suckling pigs.	1978	224841
[effect of hormones on the susceptibility of the swine cell line ib-rs-2 to foot-and-mouth disease virus].	the actions of hydrocortisone and insulin on the multiplication of foot-and-mouth disease virus were studied. the data obtained showed that the infectivity and the synthesis of the virus nucleic acid as evaluated through the plaque assay method and the kinetics of uridine-3h incorporation were increased or decreased by hydrocortisone (2 x 10(-6) m). the induction of both effects seems to be related to the carbohydrate metabolism: when the maintenance medium contained glucose or glucose plus calf ...	1978	224839
[serologic study of 2 strains of foot-and-mouth virus, cultured in cell line ib-rs-2, clone 26-3].	the antigenic characteristics of the two fmdv plaque size variants asq-pg and asq-pp were studied by serum neutralization kinetics. the results evidentiated that the antiserum asq-pg and asq-pp neutralized both variants at the same extent. the plaque population of these variants after passage in laboratory animals was compared in ib-rs-2 cells.	1978	224836
immunity to foot-and-mouth disease virus in guinea pigs: clinical and immune responses.	clinical and immune responses were determined for guinea pigs infected with different doses of foot-and-mouth disease virus (fmdv) type a12, strain 119, administered by different routes. vesicles developed on the tongue or heel pad 1 day after these areas were intradermally inoculated with fmdv. however, vesicles did not develop on the feet and tongue until 3 to 4 days after the intradermal inoculation of fmdv in the flank skin or after intracardiac or subcutaneous inoculation. infected guinea p ...	1979	223986
some aspects of fmdv-production in growing cells and a closed system for concentration of fmdv by polyethylene glycol.	different commercially available peptone preparations, all derived by enzymatic digestion of meat, were tested for their ability to replace the individual amino acids and polyethylene glycol (peg)-treated serum in bhk suspended cell culture growth medium. cell growth was not impaired if the individual amino acids were replaced by 3 g/l of peptone in combination with 3 g/l lah and 5% peg-treated bovine serum. the concentration of the latter could be reduced to 1% by gradually lowering the concent ...	1979	223924
the use of frozen bhk21 c13 cells to control the biological parameters for cell and foot-and-mouth disease virus growth.	in order to control the four primary variables (cells, serum, medium and physical conditions) in a cell or virus growth system it is important to have a reliable and constant positive control with which to compare any variable of the system components. the use of aliquots of a frozen cell population (stored at -136 degrees c) for this purpose is the subject of this paper. using such cells, tests have been established for the control of sera, media, cell susceptibility and the quality of serum tr ...	1979	223922
cell culture on beads used for the industrial production of foot-and-mouth disease virus.	the microcarrier culture technique has been applied to a pig kidney cell line. microcarriers consisted of deae sephadex a 50 beads washed and containing carboxymethyl cellulose. sifted beads gave better results than unclassified material. cells for inoculum were prepared in roux flasks. the two types of fermentors which were used (operating capacity 100 l and 150 l) gave similar results. the growth of the cells can easily be followed by microscopic observation and cell count. the yields of cells ...	1979	223917
development of a methodology for the production of foot- and- mouth disease virus from bhk21 c13 monolayer cells grown in a 100 l (20 m2) glass sphere propagator.		1979	223915
sequence and location of the poly c tract in aphtho- and cardiovirus rna.	the poly c tract in the rna of the aphtho- and cardio viruses has been examined in several isolates of foot-and-mouth disease virus (fmdv) and encephalomyocarditis (emc) virus. the length of the tract is variable, containing 100 to 170 bases in the fmdv isolates and 80 to 250 bases in the emc virus isolates. each poly c tract contains c. 10% a and u residues, located at the 5' end, i.e. most of the tract is a continuous run of c residues. the position of the tract on the genome was the same in e ...	1979	223128
the specific detection of foot-and-mouth disease virus whole particle antigen (140s) by enzyme labelled immunosorbent assay.	a solid-phase micro-enzyme-labelled immunosorbent assay (elisa) using guinea pig antiserum against purified (140s) inactivated foot-and-mouth disease (fmd) virus has been used in a sandwich technique to specifically measure 140s virus in the presence of 12s material.	1979	222837
purification of foot-and-mouth disease virus infection-associated antigen.		1978	221935
cross reactions of normal bovine serums with foot-and-mouth disease virus.		1977	220636
immune response of neonatal swine to inactivated foot-and-mouth disease virus vaccine with oil adjuvant. i. influence of colostral antibody.		1977	220635
[radial immunodiffusion study of foot-and-mouth disease virus type a].	the radial immunodiffusion(ri), was used to study f. m. d. viruses, type a. it was found that the specific linkage between f. m. d. antigens and antibodies could be demonstrated through ri with the formation of precipitation circles. it was demonstrated that specific reactions were produced when homologus or heterologus antigens and sera of one and the same f. m. d. virus type interacted. the size of the precipitation circles proved inversely proportional to the concentration of antibodies in th ...	1978	219587
detection and quantification of foot and mouth disease virus by enzyme labelled immunosorbent assay techniques.	enzyme labelled immunosorbent assays (elisa) have been developed to detect and quantify foot and mouth disease (fmd) virus using flexible plastic microtitre plates. the methods were successful for the specific detection of fmd virus and were 50 to 100 times more sensitive than the complement fixation test. the application of the elisa techniques to fmd virus typing and subtyping, and to the assay of antigen concentration during manufacture of vaccines is discussed.	1979	219137
relationship between virus neutralization and serum protection bioassays for igg and igm antibodies to foot-and-mouth disease virus.	the time interval between administering the serum and the virus was found to influence the results of the in vivo mouse protection test for foot-and-mouth disease antibodies. in particular, for both igg and igm antibodies to strain a12 virus, the mouse protection index increased from zero to a maximum at about 6 h and remained high for at least five days. variations in the antiserum concentration, on a log scale, had a proportional effect on the mouse protection index, if between 1 and 3. the co ...	1979	219135
stability and immunogenicity of empty particles of foot-and-mouth disease virus.	three strains of foot-and-mouth disease virus were shown to contain significant amounts of naturally occurring 75s, empty particles as well as the infectious, 140s full particles. one of these strains--a pando (1970)--was studied in detail. the empty particles from this virus strain were shown to have an observed sedimentation coefficient of 67s in 0.04 m phosphate buffer; they were labile in sds, non-infectious and probably rna-free and, on heating, they broke down to 12s subunits as did the 14 ...	1979	218538
[micromethod of determining the complement-binding properties of commercial series of the foot-and-mouth disease virus].	investigations were carried out to establish the possibility of using a micromethod of the complement-fixation test to determine the complement-fixing properties of productional series of the foot-and-mouth disease virus. it was found that the micromethod referred to is an economically profitable and practically simple one. it is readily applicable requiring no particular apparatuses and equipment, is specific, and can successfully be used instead of the routinely employed cft method. the microm ...	1978	218334
[early events in the replication of foot and mouth disease virus: subcellular localization of viral rna synthesis].		1977	218264
the n-terminal sequence of three coat proteins of foot-and-mouth disease virus.		1978	217392
[formation of immunity in sheep inoculated with varying doses of the foot-and-mouth disease virus 0194].		1979	217141
inactivated-concentrated virus antigen for indirect complement fixation test of foot-and-mouth disease.	to the culture fluids of bhk-21 cells infected with each of types o, a, and asia 1 of foot-and-mouth disease virus was added acetylethyleneimine to 0.05% (v/v). the mixtures were incubated at 37 degrees c for 24 hours. to them were then added polyethylene glycol 6000 to 10% (w/v), and the mixtures concentrated to one-tenth of the initial volume. the resulting inactivated-concentrated virus antigens showed a complement fixation (cf) titer ranging from 12 to 24. the recovery rate of cf activity wa ...	1978	216926
immune response to virus-infection-associated (via) antigen in cattle repeatedly vaccinated with foot-and-mouth disease virus inactivated by formalin or acetylethyleneimine.	the results of experiments to investigate antibody to 'virus infection associated' (via) antigen in cattle repeatedly vaccinated with formalin- or acetylethyleneimine- (aei) inactivated foot-and-mouth disease (fmd) vaccines under laboratory conditions are reported. results are also presented from some vaccinated animals subsequently exposed to fmd infection. antibody against via was not detected before and after the first vaccination with formalin or aei-inactivated vaccine but did develop in al ...	1979	216744
excretion of foot-and-mouth disease virus in oesophageal-pharyngeal fluid and milk of cattle after intranasal infection.	the virus growth in the pharyngeal area and the virus excretion in milk of susceptible and vaccinated dairy cows after intranasal instillation of foot-and-mouth disease (fmd) virus type o1 were examined. ten vaccinated cows were purchased through a market. of these, nine had delivered their first calf. the cows were inoculated 2-9 months after having received the last dose of vaccine. all vaccinated cows resisted the intranasal challenge. the virus multiplied in the pharyngeal area but, compared ...	1978	215675
[determination of the amount of the 140s-component of foot-and-mouth disease virus].		1978	214930
a re-appraisal of the biochemical map of foot-and-mouth disease virus rna.	the proteins induced by infection of bhk 21 cells with foot-and-mouth disease virus have been compared by tryptic peptide analysis. the results indicate that there are three primary products 5'--p88, p52, p100--3'. the polypeptide p56, which we considered previously to be a primary product, is derived from the region of the genome that codes for p100. the results indicate that there are alternative cleavage pathways of p100, the polypeptide coded for by the 3' end of the genome.	1978	214522
early events in the interaction between foot-and mouth disease virus and primary pig kidney cells.	foot-and-mouth disease virus (fmdv) attached to pig kidney cells at 0 degrees c and could only be recovered in a form with a sedimentation coefficient and buoyant density lower than that of the native virus. incubation of the virus-cell complex at 37 degrees c caused disruption of about 80% of the particles into a 12s protein sub-unit that had the same polypeptide composition as that produced by reducing the ph of the virus below ph7. the remaining 20% had the same polypeptide and rna compositio ...	1978	214518
isolation of immunizing cyanogen bromide-peptides of foot-and-mouth disease virus.		1978	214084
preadsorption of boar semen with kaolin: increased efficiency of foot-and-mouth disease virus detection.	the boar semen-associated cytotoxic factor(s), but not the antiviral activity, were removed by adsorption with kaolin. although foot-and-mouth disease virus was efficiently removed from medium by kaolin or kieselguhr, the virus was not removed from semen-virus mixtures. because the cytotoxicity induced by boar semen apparently altered the ability of tissue culture cells to support virus replication, preadsorption with kaolin increased the probability of detecting this virus in semen samples.	1978	213994
the effect of cesium salts on dense poliovirus particles.	the buoyant density of dense poliovirus particles has been examined in density gradients other than cesium chloride in order to determine the dependence of this property on the nature of the solvent. in urografin (sodium and methylglucamine amidotrizoate), dense poliovirus particles banded at two densities--1.33 and 1.39 g/cm(3)--whereas in cesium metrizoate they banded only at 1.39 g/cm(3) and in cesium sulfate at 1.38 g/cm(3). the presence of cesium ions gives rise to the occurrence of dense p ...	1978	213398