Publications

the mechanism of translation of cowpea mosaic virus middle component rna: no evidence for internal initiation from experiments in an animal cell transient expression system.	the possibility that internal initiation of translation is responsible for the synthesis of the middle component (m) rna-encoded 95k protein of cowpea mosaic virus (cpmv) has been investigated by constructing plasmids in which the entire sequence of cpmv m rna was cloned downstream of a chloramphenicol acetyltransferase gene. expression of these plasmids in an animal cell expression system revealed that no synthesis of the proteins encoded by the downstream cpmv open reading frame takes place fr ...	1991	1765773
virus survival in the environment.	viruses pass into the environment from clinically ill or carrier hosts; although they do not replicate outside living animals or people, they are maintained and transported to susceptible hosts. population concentrations and movement, both animal and human, have been steadily increasing in this century, enhancing transmission of respiratory and enteric viruses and compounding the difficulty of preventing environmental transmission. studies on environmental survival factors of viruses have been m ...	1991	1782426
[outbreak of foot-and-mouth disease in northern benin during the 1990-1991 dry season].	an outbreak of foot-and-mouth disease damaged the north-benin during the 1990-1991 dry season (november to may). coming from outside the benin, it spread out very quickly in the country essentially because of trans-humant herds. no measures have been taken to limit this sickness which is endemic and which regularly exhibits outbreaks in benin. antibodies to types a, o and sat2 of the foot-and-mouth disease virus were detected in the sera during this outbreak.	1991	1824131
human rhinovirus 14 complexed with antiviral compound r 61837.	the binding of the antirhinoviral agent r 61837 to human rhinovirus 14 has been examined by x-ray crystallographic methods. the compound r 61837 binds in the same pocket (underneath the canyon floor) as the "win" antirhinoviral agents. it does not penetrate as far into the pocket but causes similar conformational changes in the virus capsid. the movement of residues 1217 to 1221 of viral protein 1 (in the "fmdv loop") is more pronounced for r 61837 than for win compounds. although both r 61837 a ...	1991	1847215
high-affinity antibody induced by immunization with a synthetic peptide is associated with protection of cattle against foot-and-mouth disease.	previous work has shown that the synthetic peptide c-c-(200-213)-p-p-s-(141-158)-p-c-g, in which residues 200-213 and 141-158 correspond to immunogenic regions of the vp1 protein of foot-and-mouth disease virus (fmdv), is capable of inducing high levels of neutralizing antibody but only inconsistent protection of cattle against virulent fmdv challenge. the possibility exists that differences in affinity may well underlie the observed variations in biological effectiveness of the anti-peptide ant ...	1991	1847695
evidence for dissimilar properties of comoviral and picornaviral rna polymerases.	the poliovirus rna polymerase has been synthesized in spodoptera frugiperda cells by using the baculovirus expression system. crude sonicates of these cells exhibited an rna-elongating activity of a synthetic oligo(u) primer with poly(a) or cowpea mosaic virus (cpmv) rna as a template. a similar polymerase activity was found in extracts of insect cells in which foot-and-mouth disease virus (fmdv) proteins, including the putative polymerase, were produced. the analogous cpmv 87k protein and sever ...	1991	1848591
myristoylation of foot-and-mouth disease virus capsid protein precursors is independent of other viral proteins and occurs in both mammalian and insect cells.	the myristoylation of the foot-and-mouth disease virus (fmdv) capsid precursor p1-2a and its amino-terminal cleavage product 1ab, expressed from subgenomic cdna, has been analysed. the modification reaction is independent of other fmdv proteins and occurs in both mammalian and insect cells. blocking of the myristoylation site does not prevent efficient processing of the fmdv capsid precursor. a cdna cassette in which the leader protease sequence is substituted by an atg codon produces myristoyla ...	1991	1848606
mouse protection test as a predictor of the protective capacity of synthetic foot-and-mouth disease vaccines.	a passive immunity test (mpt) in suckling mice for the quantification of protective anti-foot-and-mouth disease virus (fmdv) antibodies in serum is described. comparisons with titres obtained using conventional serum neutralization tests show that for cattle given synthetic peptide vaccines this in vivo assay is a better indicator of protection, while for convalescent animals and virus-vaccinates both tests are equally valid predictors of immune status. cleavage of fc fragments from anti-virus o ...	1991	1848960
protection conferred by trpe fusion proteins containing portions of the c-terminal region of capsid protein vp1 of foot-and-mouth disease virus.	major immunogenic sites of foot-and-mouth disease virus (fmdv) have been mapped to the c-terminal third of capsid protein vp1; we studied the immunogenicity of a series of trpe-fmdv fusion proteins containing this region of fmdv strain o1 campos. fusion protein trpe-dcn, which contains a dimer of vp1 amino acid sequences consisting of amino acids 200 to 213 linked by a diproline spacer to amino acids 141 to 158 (200-213 approximately p-p-g approximately 141-158), induced the best response. a sin ...	1991	1849980
rapid isolation of monoclonal hybridoma cultures by a 'fusion-cloning' method: the requirement for aminopterin.	hybridomas were generated by fusing the balb/c sp2/0 myeloma-like cell line with either: (i) splenocytes from balb/c mice immunized with foot-and-mouth disease virus (fmdv), rinderpest virus (rpv), peste des petits ruminants virus (pprv), african swine fever virus (asfv) or pig thymocytes; or (ii) lymph node cells from cattle immunized with fmdv. if the fusion mixtures were plated in cloning medium of methyl cellulose and hat medium, small hybridoma colonies developed which rarely survived. fusi ...	1991	1954000
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
embryo transfer as a means of controlling the transmission of viral infections. xiii. failure to transmit foot-and-mouth disease virus through the transfer of embryos from viremic donors.	a total of 436 embryos/unfertilized ova was collected from 30 foot-and-mouth disease (fmd) viremic cattle; 106 of these embryos/ova were from eight donors that had fmd virus in their reproductive tracts. the 436 embryos/ova were washed and then either assayed in cell culture or intradermally in steer tongues or transferred to recipients. foot-and-mouth infectivity was not found to be associated with any of the embryos/ova assayed in cell culture or intradermally. the 149 embryos transferred prod ...	1991	16726913
peptides as viral vaccines: lessons from experiments with foot-and-mouth disease virus.	the highly variable sequence encompassing amino acids 141-160 of vp1, one of the four capsid proteins of foot-and-mouth disease virus, elicits neutralizing antibodies in a range of experimental animals. the sequence has been synthesized chemically by merrifield's solid phase method and biochemically as part of different fusion proteins. by incorporating the peptide into the core protein of hepatitis b virus, particles are produced which elicit levels of neutralizing antibody approaching those ob ...	1991	24424921
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
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
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 ...	1992	1372368
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 ...	1992	1374806
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 ...	1992	1375405
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 ...	1992	1375792
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 ...	1992	1376255
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 ...	1992	1378734
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 ...	1992	1378821
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 ...	1992	1379398
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
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
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
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 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
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
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
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
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
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
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
foot-and-mouth disease virus populations are quasispecies.		1992	1318185
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
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
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
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
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
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
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
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
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 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
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
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
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
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
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
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
[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
[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
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
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
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
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
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
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
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
expression of the vp3-vp1 sequence of foot-and-mouth disease virus in escherichia coli.	1. cdna recombinants containing the vp3 and vp1 sequences of foot-and-mouth disease virus were isolated and the vp3-vp1 sequence was reconstructed. 2. the reconstructed vp3-vp1 sequence was subcloned into expression vector pex31b and a fusion protein of about 62,000 da was expressed. 3. when injected into mice, the fusion protein was able to elicit the production of antibodies that recognized viral vp1 and vp3. 4. antibodies present in sera from mice immunized with vp3-vp1 protein did not neutra ...	1993	7504968
characterization of foot-and-mouth disease virus by monoclonal antibodies.	monoclonal antibodies (mabs) were produced against foot-and-mouth disease (fmd) virus types o1 campos br1/58, a24 cruzeiro br1/55, and c3 indaial br1/71, which are the strains used for production of fmd vaccines in the majority of south american countries. within the library of mabs produced, a group was selected on the basis of their neutralizing titer in cell culture, protective titer in suckling mice, sensitivity to trypsin, and specificity for virus structural proteins. the mabs were utilize ...	1993	7507329
topology of phoe porin: the 'eyelet' region.	a model for the topology of the phoe porin has been proposed according to which the polypeptide traverses the outer membrane sixteen times mostly as amphipathic beta-sheets, thereby exposing eight loops at the cell surface. until now, no evidence has been obtained for the surface exposure of the third loop. recently, the structure of porin of rhodobacter capsulatus has been determined. the proposed model of phoe is very similar to the structure of the r. capsulatus porin, which has an 'eyelet' r ...	1993	7679770
amino acid changes outside the g-h loop of capsid protein vp1 of type o foot-and-mouth disease virus confer resistance to neutralization by antipeptide g-h serum.	antiserum to a peptide corresponding to the 135-154 sequence of capsid protein vp1 of the foot-and-mouth disease virus o1 kaufbeuren was raised in a pig. although this serum contained neutralizing antibodies, the pig showed clinical symptoms after challenge. virus isolated from this pig was identified as a mutant, with changes at positions 50, 198 and 211 of vp1 and at position 209 of vp2. this mutant, as well as a plaque isolate of it, differing from the challenge virus at positions 198 on vp1 ...	1993	7680514
genotypic and phenotypic changes of bhk-21 cells grown in suspension cultures.	the propagation of foot-and-mouth disease virus on bhk-21 suspension cells, although economically convenient, may yield a scarcely immunizing antigen. helpful insights were obtained by investigating a few genotypic and phenotypic features of the cell cultures. the appearance of polyploid populations, higher cell concentrations at the end of culturing, the progressive reduction of spreading on surfaces and an abnormal expression of the alpha 5 beta 1 integrin were found to be correlated with the ...	1993	7686770
cyclic disulfide model of the major antigenic site of serotype-c foot-and-mouth disease virus. synthetic, conformational and immunochemical studies.	a cyclic disulfide peptide representing antigenic site a of foot-and-mouth disease virus (fmdv) strain c-s8c1 (residues 134 to 155 of viral protein 1 (vp1) with tyr136 and arg153 replaced by cystine; ttctasargdlahlttthachl) was synthesized by solid phase methods. formation of the cyclic disulfide was carried out by air oxidation of the fully deprotected and reduced bis-cysteine precursor, under high dilution conditions. the identity of the cyclic peptide was confirmed by both physical and enzyma ...	1993	7688321
use of the enterobacterial outer membrane protein phoe in the development of new vaccines and dna probes.	phoe protein is a major outer membrane protein of escherichia coli. the polypeptide spans the membrane 16 times, thereby exposing 8 regions at the cell surface. insertions in these regions did not affect the biogenesis of the protein. therefore, we considered the possibility of using phoe as a vector for the exposure of foreign antigenic determinants at the cell surface, with the ultimate goal of constructing new (live oral) vaccines. via recombinant dna techniques, b-cell epitopes of vp1 protei ...	1993	7688607
distinct repertoire of antigenic variants of foot-and-mouth disease virus in the presence or absence of immune selection.	antigenic variants of foot-and-mouth disease virus (fmdv) were generated and frequently became dominant in clonal populations of fmdv (clone c-s8c1) grown in the absence of anti-fmdv antibodies. we have now passaged eight samples of the same fmdv clone in the presence of a limited amount of neutralizing polyclonal antibodies directed to the major antigenic site a of capsid protein vp1. complex populations of variants showing increased resistance to polyclonal sera and to site a-specific monoclon ...	1993	7690417
use of substituted and tandem-repeated peptides to probe the relevance of the highly conserved rgd tripeptide in the immune response against foot-and-mouth disease virus.	antigenic site a of foot-and-mouth disease virus (fmdv) is an exposed, mobile loop which includes a central, highly conserved arg-gly-asp tripeptide (rgd, vp1 residues 141-143 in serotype c) thought to be part of the cell attachment site. we have analyzed the contribution of rgd to the interaction of site a with antibodies by incorporating selected amino acid replacements at rgd into synthetic peptides representing site a, and analyzing the reactivity of substituted peptides with site a-specific ...	1993	7690714
the use of monoclonal antibodies in the molecular typing of animal viruses.	monoclonal antibodies (mabs) are biological reagents which have a definite structure. they identify epitopes with total specificity. such specificity is based on the exact physico-chemical structure of antigens. thus mabs provide a unique link between chemical structure and antigenic properties and can give great insight into the functional properties of biological agents. the author describes a number of applications of mabs in the characterisation of foot and mouth disease viruses for diagnost ...	1993	7691272
characterization of monoclonal antibodies against a type sat 2 foot-and-mouth disease virus.	this paper is the first to describe characterization of monoclonal antibodies (mabs) against a south african territories 2 (sat 2) foot-and-mouth disease virus (isolate rho 1/48). twelve mabs which neutralized homologous virus were characterized in indirect and sandwich elisa using purified rho 1/48 virus particles, subunits, trypsin-treated, and chemically denatured virus. all the mabs inhibited haemagglutination by parental virus. binding of the mabs to 73 sat 2 field isolates was measured in ...	1993	7691630
new observations on antigenic diversification of rna viruses. antigenic variation is not dependent on immune selection.	recent results have revealed novel features in the process of antigenic diversification of fmdv. (i) antigenic variation is not necessarily the result of immune selection. (ii) single, critical amino acid replacements may either have a minor effect on antigenic specificity or cause a drastic antigenic change affecting many epitopes on an antigenic site. (iii) the effect of such a critical replacement may be suppressed by additional substitutions at neighbouring sites. (iv) antigenic diversificat ...	1993	7691985
expression of an animal virus antigenic site on the surface of a plant virus particle.	to investigate if cowpea mosaic virus (cpmv) particles can be used to express foreign protein sequences, oligonucleotides encoding an epitope derived from vp1 of foot-and-mouth disease virus (fmdv) were cloned into the region of the cpmv genome encoding the small (s) coat protein. the chimeras were designed so that the foreign sequence was expressed either as an insertion or as a replacement for part of the wild-type sequence. while rna from both chimeras was able to replicate in cowpea protopla ...	1993	7692669
new virus-specific t-helper epitopes of foot-and-mouth disease viral vp1 protein.	immunogenicity studies of synthetic peptides from different regions of vp1 protein of foot-and-mouth disease virus strain a22 revealed the following active fragments: 39-61, 50-69, 135-159, 175-189, 170-189 and 197-213. testing of virus neutralizing antibody production in rabbits primed by peptides and then inoculated by the virus showed that only peptides 135-159 and 170-189 were able to induce the functional t-cell helper activity. localization of virus-specific t-cell recognition sites in seq ...	1993	7693508
uses of beta-galactosidase tag in on-line monitoring production of fusion proteins and gene expression in escherichia coli.	a simple method for monitoring and quantifying automatically the production by fermentation of beta-galactosidase fusion proteins, making use of the remaining activity of the beta-galactosidase part, is considered. a hybrid protein carrying the major antigenic domain of foot-and-mouth disease virus c1 joined at the n-terminus of beta-galactosidase has been expressed in escherichia coli. the yield of the chimeric protein has been monitored by flow injection analysis (fia) during batch fermentatio ...	1993	7764038
enhanced production of pl-controlled recombinant proteins and plasmid stability in escherichia coli reca+ strains.	overexpression of pl-controlled foot-and-mouth disease virus recombinant proteins was studied in escherichia coli reca+ strains and in a reca mutant. higher protein yield and extractable plasmid dna amounts were found in wild type cells, in absence of detectable reca proteolytic activity. minor but still significant differences in pbr322 dna amounts were also detected between reca+ and its reca13 and lexa1 derivatives. these data should be seriously considered to select expression systems and to ...	1993	7764065
construction and use of integrative vectors to express foreign genes in mycobacteria.	we have constructed a mycobacterial integrative vector by placing two copies of the insertion sequence is900 flanking a kanamycin-resistance gene into a 'suicide' vector unable to replicate in mycobacteria. the mycobacterium leprae gene encoding the m. leprae 18 kda protein was cloned between the two copies of is900 to provide expression signals. constructs were introduced into mycobacterium species smegmatis, vaccae and bovis bcg by electroporation and selection for kanamycin resistance. the ex ...	1993	7934874
experiments on an early protection against foot-and-mouth disease virus.	the influence of the peptide diacetylsplenopentin (sp5) on an early protection of guinea pigs against foot-and-mouth disease (fmd) was investigated. 80% protection was achieved if sp5 was applied in a dose of 2 mg one day before challenge with fmd virus (fmdv) type o1 lausanne strain. in comparison with this a conventional commercial adsorbate vaccine protected guinea pigs about 7 days after vaccination. an earlier protection can be obtained in general by vaccination with a higher content of the ...	1993	8105663
avridine and lps from brucella ovis: effect on the memory induced by foot-and-mouth disease virus vaccination in mice.	foot-and-mouth disease is one of the more economically important diseases among meat-producing biungulate species. in contrast to natural infection, current foot-and-mouth disease virus (fmdv) vaccines, prepared with inactivated virus and adjuvants, elicit short-lived protection. the immunomodulating effect on fmdv vaccines of avridine and lipopolysaccharide of brucella ovis (lps) was tested in a murine model. the duration of immunity, protection, stimulation of immunocompetent cells producing a ...	1993	8296482
[a rapid solid-phase immunoenzyme method in the diagnosis of viral infections].	an accelerated solid-phase enzyme-immunoassay has been developed which permits identification of antigens and antibodies to them within 30-40 min, even directly at the site of specimen collection. the method was tested on the models of foot-and-mouth disease virus, vesicular disease of swine, vesicular exanthema of swine, aujeszky's disease, leukemia, and coronavirus infection of cattle.	1993	8303893
comparison of surface properties of picornaviruses: strategies for hiding the receptor site from immune surveillance.	the surface topology and sequence conservation of different picornaviruses have been compared using molecular graphics and statistical analyses. the comparisons suggest that the canyons, surface depressions encircling the fivefold axes, are the sites of receptor attachment of enteroviruses as well as human rhinovirus (hrv). in hrv14, the receptor binding footprint extends beyond the canyon (olson et al. (1993), proc. natl. acad. sci. usa 90, 507-511), but these more exposed regions are not conse ...	1993	8337843
antibody-complexed foot-and-mouth disease virus, but not poliovirus, can infect normally insusceptible cells via the fc receptor.	poliovirus and foot-and-mouth disease virus (fmdv) initiate infection by binding to specific cell surface receptors, which is followed by a poorly understood disassembly process. to probe these early steps of infection, the ability of poliovirus and fmdv to infect cells following binding through an alternative receptor was examined. for these studies, a chinese hamster ovary (cho) cell line expressing the b2 isoform of the murine fc receptor (fcr) was used. both viruses were able to bind to this ...	1993	8380665
methods used in the structure determination of foot-and-mouth disease virus.	the structure of foot-and-mouth disease virus (fmdv) strain o1 bfs 1860 has been determined to 2.9 a resolution using the molecular-replacement method [acharya, fry, stuart, fox, rowlands & brown (1989). nature (london), 337, 709-716]. crystals of the virus with average dimensions 0.12 x 0.06 x 0.12 mm belong to space group i23, a = 345 a with 1/12 of the icosahedral particle per asymmetric unit giving fivefold noncrystallographic redundancy. oscillation diffraction photographs were collected at ...	1993	8382928
phenotypic and functional characterization of mouse attenuated and virulent variants of foot-and-mouth disease virus type o1 campos.	a series of genetically related variants arising from a parental wild-type isolate of o1 campos and its tissue culture adapted variant were differentiated by various cell culture markers (temperature sensitivity, plaque size, viral yield) and lethality in mice. these isolates were additionally characterized functionally and biochemically by examining poly(c) length, rna synthesis, protein synthesis, and cell receptor binding. in primary bovine kidney cells, the virulent isolates had greater leve ...	1993	8384748
structure of a major immunogenic site on foot-and-mouth disease virus.	attachment of foot-and-mouth disease virus (fmdv) to its cellular receptor involves a long and highly antigenic loop containing the conserved sequence, arg-gly-asp, a motif known to be a recognition element in many integrin-dependent cell adhesion processes. in our original crystal structure of fmdv the arg-gly-asp-containing loop ('the loop'), located between beta-strands g and h of capsid protein vp1, was disordered and hence essentially invisible. we previously surmised that its disorder is e ...	1993	8385272
foot-and-mouth disease virus proteinase 3c inhibits translation in recombinant escherichia coli.	escherichia coli cultures do not survive the expression of recombinant foot-and-mouth disease virus proteinase 3c. this effect is ascribed to degradation of bacterial protein(s), as concluded from the observation of gradual cessation of gene expression upon induction of 3c expression. most likely, translation inhibition is the cause of bacterial death, as (i) cell-free translation of the 3c gene was restored by additional bacterial ribosomes, (ii) ribosomes from proteinase 3c-producing cells dif ...	1993	8386123
the two species of the foot-and-mouth disease virus leader protein, expressed individually, exhibit the same activities.	initiation of protein synthesis on the foot-and-mouth disease virus rna occurs at two sites, thus, two forms of the leader protein, termed lab and lb, are produced. plasmids have been constructed which encode these proteins either together or individually. plasmids encoding the lab protein alone express a modified form of this protein in which the second methionine residue, which corresponds to the first amino acid of lb, is changed to an alternative residue. four different mutant forms of the l ...	1993	8386879
design of primers for pcr amplification of highly variable genomes.	a program to aid in the search of primers for specific polymerase chain reaction (pcr) amplification of highly variable genomes is presented. it involves the derivation of variability profiles to identify optimal regions for pcr amplification, taking into account stability of dna-primer hybrids. an application of the program to foot-and-mouth disease virus diagnosis is presented.	1993	8386978
an indirect sandwich elisa for the identification of bovine enteroviruses.	an indirect sandwich elisa is described for the detection of bovine enteroviruses. the assay was developed as an alternative to the complement fixation test and proved to be more sensitive and convenient. ten bovine enterovirus prototype strains were easily discriminated. no cross-reactions were observed with other picornaviruses including foot-and-mouth disease viruses, swine vesicular disease virus, porcine enteroviruses and bovine rhinovirus.	1993	8388399
conserved tertiary structural elements in the 5' nontranslated region of cardiovirus, aphthovirus and hepatitis a virus rnas.	statistical analyses of rna folding in 5' nontranslated regions (5'ntr) of encephalomyocarditis virus, theiler's murine encephalomyelitis virus, foot-and-mouth disease virus, and hepatitis a virus indicate that two highly significant folding regions occur in the 5' and 3' portions of the 5'ntr. the conserved tertiary structural elements are predicted in the unusual folding regions (ufr) for these viral rnas. the theoretical, common structural elements predicted in the 3' parts of the 5'ntr occur ...	1993	8389442
a single nucleotide substitution in the internal ribosome entry site of foot-and-mouth disease virus leads to enhanced cap-independent translation in vivo.	mutants of foot-and-mouth disease virus (fmdv) with altered biological properties can be selected during the course of persistent infection of bhk-21 cells with fmdv c-s8c1 (j. c. de la torre, e. martínez-salas, j. díez, a. villaverde, f. gebauer, e. rocha, m. dávila, and e. domingo, j. virol. 62:2050-2058, 1988). two nucleotide substitutions, u to c at position -376 and a to g at position -15, (counting as +1 the a of the first functional aug), were fixed within the internal ribosome entry site ...	1993	8389904
detection of foot-and-mouth disease virus rna in clinical samples and cell culture isolates by amplification of the capsid coding region.	foot-and-mouth disease is one of the most economically important virus diseases of livestock. two important requirements for the control of this disease are rapid laboratory diagnosis and epidemiological investigation. the use of the polymerase chain reaction method (pcr) to amplify specific nucleic acid regions offers the unique possibility of combining swift viral detection with the production of genetic material suitable for sequencing and other methods of molecular epidemiological analysis. ...	1993	8391540
rhipicephalus zambeziensis unlikely to transmit foot-and-mouth disease virus.	the potential of the ixodid tick, rhipicephalus zambeziensis, was investigated as a vector in the transstadial transmission of the foot-and-mouth disease virus by feeding nymphae on viraemic (log 1.0-4.0 tcid50/ml) cattle. suspensions were prepared, at various intervals after detachment, from pools of engorged nymphae--some of which were allowed to moult first. suspensions were inoculated into sucking mice, cell cultures and, in some cases, cattle to detect the fmd virus. newly moulted adult tic ...	1993	8392681
the carrier state in foot and mouth disease--an immunological review.	the carrier state in foot and mouth disease (fmd) is characterized by the asymptomatic low-level excretion of foot and mouth disease virus (fmdv) from the oropharynx of ruminants for periods that are species and virus strain-dependent. persistent infection with fmdv readily occurs following the failure of virus elimination at the acute stage of infection, a process thought to be mediated through the phagocytosis of antibody/virus immune complexes. recent evidence supports the view that carrier c ...	1993	8392891
large-scale use of liquid-phase blocking sandwich elisa for the evaluation of protective immunity against aphthovirus in cattle vaccinated with oil-adjuvanted vaccines in argentina.	specific serum activity levels against four reference strains of foot-and-mouth disease virus (fmdv) were evaluated from 1634 animals vaccinated with commercial quadrivalent oil vaccines and from 746 unvaccinated, naive animals, using the liquid-phase blocking sandwich elisa (lpelisa) test. cows from the fmdv-free area of argentina were tested for the absence of specific fmdv antibodies (sp fmdv abs) and those showing lpelisa titres < 1.0 were grouped in lots of 16 animals. they were vaccinated ...	1993	8393607
a comparative study of the immune responses of sheep against foot-and-mouth disease virus types asia-1 and o peg-concentrated aluminium hydroxide gel and oil-adjuvanted vaccines.	foot-and-mouth disease (fmd) vaccines prepared against types asia-1 and o peg-concentrated and adjuvanted with aluminium hydroxide gel were compared with oil-adjuvanted types asia-1 and o vaccines in sheep. the study was conducted by inoculating 0.5 ml of monovalent vaccine under laboratory conditions and 1 ml dose of bivalent vaccine in field conditions. the antibody responses were monitored by serum neutralization and elisa tests. the results indicate that peg-concentrated gel vaccine was of c ...	1993	8393608
identification of a fifth neutralizable site on type o foot-and-mouth disease virus following characterization of single and quintuple monoclonal antibody escape mutants.	a monoclonal antibody (c3) produced against foot-and-mouth disease virus type o1caseros was found to neutralize quadrivalent monoclonal antibody escape mutant (g67) of foot-and-mouth disease virus type o1kaufbeuren. this mutant had been characterized at the sequence level as having distinct changes affecting four non-overlapping neutralizable sites. the c3 monoclonal antibody was used to prepare a quintuple escape mutant from the g67 and a single escape mutant from the parental o1kaufbeuren viru ...	1993	8393912
genetically engineered foot-and-mouth disease viruses with poly(c) tracts of two nucleotides are virulent in mice.	to determine the role of the poly(c) tract found at the 5' end of the genome of foot-and-mouth disease virus, synthetic rnas (in vitro transcripts) with poly(c) tracts of different lengths have been produced and evaluated. rnas with poly(c) tracts of 35, 25, 16, 6, or 2 residues displayed similar specific infectivities in baby hamster kidney (bhk) cells. viruses recovered from cells transfected with in vitro transcripts containing 6 to 35 cs had properties similar to those of the wild-type virus ...	1993	8394441
protection of swine against foot-and-mouth disease with viral capsid proteins expressed in heterologous systems.	three groups of swine were each inoculated with a different antigen preparation of foot-and-mouth disease virus (fmdv) capsid proteins and challenged by contact exposure to animals infected with fmdv. one group of four animals was inoculated with an extract from cells infected with a recombinant baculovirus containing the fmdv p1-2a structural protein precursor gene and a portion of the p2 gene. two out of four animals were protected from clinical disease, but not from virus replication. a secon ...	1993	8395128
the detection of foot-and-mouth disease virus in oesophageal-pharyngeal samples by a polymerase chain reaction technique.	a polymerase chain reaction (pcr) technique was used to detect the presence of foot-and-mouth disease virus (fmdv) in oesophageal-pharyngeal(op) samples from experimentally infected steers. ten-fold dilutions of op samples were also diluted, inoculated onto lamb kidney cell cultures, and incubated overnight. the cultures that did not show overt cytopathogenic effects (cpe) of fmdv infection were frozen and thawed; both the fluid and the cell pellet were tested by the pcr technique. the pcr detec ...	1993	8395537