Publications

hybridoma cell lines secreting monoclonal antibodies against foot-and-mouth disease virus. 1. cell culturing requirements.	the production of hybridoma cell lines secreting antibody against foot-and-mouth disease virus (fmdv) was more difficult than the production of similar cell lines secreting antibody against vesicular stomatitis virus or measles virus. a rapid and efficient protocol for the selection and culturing of 'anti-fmdv' hybridoma cultures was therefore developed and is described. this required the determination of the optimal culture medium (commercially available), source of serum supplement, line of my ...	1983	6309848
hybridoma cell lines secreting monoclonal antibodies against foot-and-mouth disease virus (fmdv). ii. cloning conditions.	three methods of cloning hybridoma cells--picking colonies from the masterplate, limit dilution cloning, and cloning in semi-solid medium over macrophage (m phi) feeder layers--were compared. cloning in semi-solid medium was found to be the most efficient and reliable, especially with our relatively slow growing anti-foot-and-mouth disease virus (fmdv) antibody secreting hybridoma cells. the optimum culture dish for this cloning was the 6-well (6w) dish (well diameter 1.5 cm), while the optimum ...	1983	6309849
an investigation into causes of resistance of a cloned line of bhk cells to a strain of foot-and-mouth disease virus.	the reduced ability of foot-and-mouth disease virus (fmdv) strain asia 1 iran 1/73 to replicate in the cloned bhk cell line aa7 was not due to lack of virus attachment at the cell surface. instead, the main restriction in the viral growth cycle occurred during synthesis and processing of viral macromolecules, and/or during the earliest stages of their assembly. reduced efficiency of penetration and uncoating of virus attached to the cells may also have contributed to inhibition of virus replicat ...	1983	6310850
immunogenicity of foot-and-mouth disease virus type o1 replicated in either monolayer or suspended bhk cell system.	the efficacy of vaccines formulated from the 10th passage of foot-and-mouth disease virus (fmdv) type o1 in monolayer baby hamster kidney (bhk) cells and the 8th passage in suspension bhk cells was compared in steers. the vaccines were inactivated with ethylenimine, contained an equal amount of antigen and were emulsified in oil-adjuvant. six animals were vaccinated with each vaccine. during the challenge of immunity (91 days post-vaccination, dpv), one out of the six steers from the monolayer v ...	1983	6297845
point mutations in polypeptide vp1 of foot-and-mouth disease virus affect mouse virulence and bhk21 cell pathogenicity.	virus produced in the first four days after infection of a bhk21 culture was shown to differ from that produced later in the infection. the early virus caused large plaques in ib-rs-2 cell sheets, had a slow cytopathic effect in bhk21 cultures and showed a high virulence for suckling mice. in contrast, the late virus caused small plaques, was rapid in its cytopathic effect and was of low virulence for mice. comparison between one clone each of the early and late virus showed that no change in im ...	1983	6307221
[differentiation of foot-and-mouth disease viruses by an enzyme-bound immunosorbent micromethod (elisa)].	fixed were the optimal conditions for the employment of the elisa method. the latter was successfully applied to differentiate and study the foot-and-mouth disease viruses. it was found that elisa was almost fifty times more sensitive as against the passive hemagglutination test, and almost one-hundred times more sensitive than the complement-fixation test. the results were found to correlate fully in the investigation of f. m. d. viruses of various origin with the use of the diagnostic methods ...	1983	6308884
the detection and inhibition of proteolytic enzyme activity in concentrated preparations of inactivated foot-and-mouth disease virus.	proteolytic enzyme activity was detected in a large number of concentrated preparations of inactivated foot-and-mouth disease virus. several lines of evidence indicated that at least some of this activity could be attributed to bhk cells, although low levels of microbial contamination in many of our preparations could not be discounted and would certainly enhance the cellular proteolytic activity. from an experiment with different concentrations of trypsin, it was concluded that the proteolytic ...	1983	6300129
mode of penetration and intracellular localization of incoming parental foot and mouth disease virus (fmdv) in bhk cells.	the process of penetration and subsequent early stages of replication of foot and mouth disease virus (fmdv) in bhk21 cell cultures have been studied in order to obtain further data about the infectious cycle of this virus. results suggest that fmdv penetrates bhk21 cells by way of pinocytic vesicles. studies of lysosomal (lf) and supernatant (sf) fractions of homogenized suspension of infected cells were carried out to learn the percentage of possible non-specific absorption of infectious virus ...	1983	6302446
identification of an exposed region of the immunogenic capsid polypeptide vp1 on foot-and-mouth disease virus.	iodination of intact foot-and-mouth disease virus results in the selective labeling of vp1, substantiating its exposed location on the virion. a comparison of tryptic peptides revealed that a single tyrosine-containing peptide was labeled with iodine on intact or protease-cleaved virus. the labeled peptide from intact and protease-cleaved virus was characterized by molecular weight sizing and sequence analysis. carboxypeptidase digestion of intact vp1, limited trypsin-cleaved vp1, and vp1 purifi ...	1983	6186823
the influence of normal guinea-pig serum and tissue culture assay system on foot-and-mouth disease virus neutralisation.	the inclusion of normal guinea-pig serum in neutralisation reactions involving foot-and-mouth disease virus (fmdv) increased the neutralisation titre and rate of neutralisation by guinea-pig antiserum derived from animals convalescent from fmdv. such inclusion had little or no effect on neutralisation involving guinea-pig antiserum collected early in infection or early or convalescent bovine antisera. higher neutralisation titres and more rapid neutralisation were found from assay in bovine thyr ...	1983	6189669
synthetic peptides mimic subtype specificity of foot-and-mouth disease virus.	the major immunogen of foot-and-mouth disease virus (fmdv) is located between amino acids 141-160 of the capsid protein vp1. synthetic peptides corresponding to the major immunogenic region give good neutralising antibody responses and protection in guinea pigs. to define more precisely the immunogenic site of the virus, we have examined serological differences between subtypes of the a serotype using synthetic peptides covering the 141-160 region. we show that these synthetic peptides carry det ...	1983	6190676
comparison of the major antigenic determinants of different serotypes of foot-and-mouth disease virus.	complete nucleotide sequences which code for the capsid protein vp1 of two foot-and-mouth disease virus serotypes, o1campos/brazil/58 and c3indaial/brazil/71, have been determined. ten available vp1 sequences (three serotype o, three serotype c, and four serotype a) were aligned and compared. our evidence suggests that o1bfs/britain/68 and o1k/germany/66 are closely related to o1campos/brazil/58. significant variations were observed between the nucleotide sequences of c3indaial determined by two ...	1983	6194313
the molecular basis of the antigenic variation of foot-and-mouth disease virus.	we have cloned and sequenced the viral protein (vp1)-coding regions of two foot-and-mouth disease virus (fmdv) serotypes (c1 and a5). comparison of the derived amino acid sequences with the known vp1 sequence of fmdv o1k and the two fmdv a subtypes a10 and a12 shows two highly variable regions in the protein, at positions 40-60 and 130-160, as possible antigenic sites. in both variable regions, several sites could be detected where all three sequences of the a subtypes are identical but the thre ...	1983	6194987
[isolation of foot-and-mouth disease virus antibodies using affinity chromatography].		1983	6197566
observations on the stability of foot and mouth disease vaccine antigens.	the 146s particle of the foot and mouth disease virus which is used as a vaccine antigen was found to be relatively stable when stored for prolonged periods at 4 degrees c. however, stored antigens of virus strains of the sat serotypes but not of a virus strain of the type o serotype became less thermostable at 37 degrees c following 4 degrees c storage. vaccines returned from the field 10 months after they were made were shown to contain significant amounts of 146s antigen of the o, a, sat 1 an ...	1983	6099640
computerization of foot and mouth disease virus strain relationship data.	since 1976 the two dimensional microneutralization test has been adopted in our laboratory as the reference test for foot and mouth disease virus (fmdv) strain differentiation. large numbers of homologous-heterologous comparisons have been performed and manual storage and retrieval of the data had become cumbersome. the objective of computerization was to provide a databank with fast easy access to enable accurate statistical calculations to be performed on the raw data entries and to simplify t ...	1983	6099643
the main antigenic determinant detected by neutralizing monoclonal antibodies on the intact foot-and-mouth disease virus particle is absent from isolated vpi.	neutralizing monoclonal antibodies raised against intact foot-and-mouth disease virus type o1 reacted with intact virus and trypsin-treated virus particles. some of the monoclonal antibodies showed a slight but definite reaction with the 12s subunit, but none of them reacted with the isolated capsid protein vp1 or any of the other viral proteins. these results confirm the difference between the neutralizing antigenic determinants exposed on intact virus particle and on isolated capsid protein vp ...	1983	6188800
transformation and foot and mouth disease virus (fmdv) productivity of some bhk cell lines.		1983	6140842
[effects of temperature and inactivators on strains of foot-and-mouth disease virus in colombia].		1984	6091209
induction of antibody to foot-and-mouth disease virus in presensitized mouse spleen cell cultures.	cultures of spleen cells from immunized mice were stimulated in vitro by soluble preparations of purified foot-and-mouth disease virus. virus-specific antibody, as detected by an enzyme-linked immunosorbent assay, was produced by immune spleen cells but not by normal, nonimmune cells. the optimal specific response was obtained with 1 microgram of virus per ml of culture; as the virus concentration was increased, the production of specific antibody was reduced. for very low concentrations of viru ...	1984	6092687
a rapid enzyme-linked immunosorbent assay for the detection of foot-and-mouth disease virus in epithelial tissues.	a rapid double sandwich enzyme-linked immunosorbent assay (elisa) has been used for the identification and type differentiation of foot-and-mouth disease (fmd) viruses in epithelial tissue samples submitted for diagnosis from the field. no difficulty was experienced in the direct typing of freshly harvested epithelium from recently ruptured vesicles by the complement fixation (cf) test or elisa. the elisa was more sensitive and specific, but proved no more efficient than the traditional cf test ...	1984	6093338
[electrical properties of the foot-and-mouth disease virus].	it has been shown that the electron microscopy method can be used for characteristics of the electric properties of foot-and-mouth disease virus. the appearance of simultaneous positive and negative staining during the negative staining of virus preparations with 3-4% ptv solution shows the presence of full virions of constant poles designated as positively and negatively stained areas of protein coat surface. the lateral orientation of virions on the film at routine conditions of preparation an ...	1984	6087939
inactivation of foot-and-mouth disease virus vaccine strains by activation of virus-associated endonuclease.	a new inactivation process for foot-and-mouth disease virus (fmdv) has been developed. this process is based on the activation of the fmdv endonuclease by incubation of unfractionated viral suspension or purified virions at 37 degrees c in the presence of high concentrations of monovalent cations such as k+, cs+ or nh4+ at ph 8.5. this procedure completely inactivated several fmdv vaccine strains yielding preparations having similar amounts of 140s particles to untreated controls. the inactivati ...	1984	6088682
nucleotide sequence and genome organization of foot-and-mouth disease virus.	a continuous 7802 nucleotide sequence spanning the 94% of foot and mouth disease virus rna between the 5'-proximal poly(c) tract and the 3'-terminal poly(a) was obtained from cloned cdna, and the total size of the rna genome was corrected to 8450 nucleotides. a long open reading frame was identified within this sequence starting about 1300 bases from the 5' end of the rna genome and extending to a termination codon 92 bases from its polyadenylated 3' end. the protein sequence of 2332 amino acids ...	1984	6089122
the stability and potency of vaccines prepared from inactivated foot-and-mouth disease virus concentrates.	the stability of 146s particles in concentrates of foot-and-mouth disease virus stored at 4 degrees c was similar to that of 146s particles in a conventional virus preparation. proteolytic degradation of vpl was not observed in the stored conventional virus preparation or inhibitor-supplemented concentrate but was observed in a supplement-free concentrate. the potencies of vaccines made from the conventional and concentrated preparations and stored in parallel at 4 degrees c appeared to decrease ...	1984	6090464
response of sheep vaccinated with large doses of vaccine to challenge by airborne foot and mouth disease virus.	administration of three-fold or six-fold larger doses of conventional monovalent type o foot and mouth disease (fmd) vaccine to sheep prevented viraemic distribution of virus after exposure to airborne virus one week later. however, virus replication in the respiratory tract or excretion in oesophageal-pharyngeal fluids and breath was not prevented. the implication of these findings for the use of vaccine as an adjunct to a 'stamping out' policy for countries which are free from fmd and which do ...	1984	6099647
an indirect sandwich enzyme labelled immunosorbent assay for the detection of foot and mouth disease virus immunizing antigen in tissue culture harvests.	the optimum conditions for an indirect sandwich enzyme-linked immunosorbent assay for foot and mouth disease virus 140s antigen assay are described. factors which could contribute to the variation in the test were investigated and a calibration coefficient for the conversion of elisa values to antigen concentration in micrograms of 140s antigen per millilitre was calculated. antigen mass in nine tissue culture harvests was estimated and these correlated well with estimates made by sucrose densit ...	1984	6098580
the differentiation of foot and mouth disease virus strains using an indirect sandwich enzyme-linked immunosorbent assay saturation model.	sigmoid saturation curves were fitted to the results of titrations of antiserum to foot and mouth disease virus against homologous and heterologous virus strains. differentiation of strains was readily evident from the different levels of the homologous and heterologous curves. these differences could be quantified by comparison of the saturation curve parameters k and prmax. factors which affect variations in k and prmax and their biological significance were investigated by varying the first p ...	1984	6098582
an international collaborative study on foot and mouth disease virus assay methods. 1. virus infectivity and neutralizing antibody assays.	in a collaborative study sponsored by the european commission for the control of foot and mouth disease, workers in 19 laboratories participated in the early phases (1, 2 and 4). all three phases were devoted to assessments of virus infectivity and the neutralizing activity of sera. virus preparations and antisera distributed from one laboratory were tested either by 'in house' or suggested methods. analyses of the results clearly showed that whilst 'within' laboratory variation in the results o ...	1984	6098584
reconstitution of immunosuppression mice with mononuclear cells from donors sensitized to foot-and-mouth disease virus (fmdv).	passive transfer experiments were performed to serve as a basis for analyzing the immune response of adult mice to fmdv infection. animals were irradiated (750 rad: 1 lethal dose 50%) and reconstituted with allogeneic mononuclear cells from blood, spleen, thymus and peritoneal cavity from donors 2 and 8 days post-inoculation (p.i.). donors were primed with 10 000 suckling mouse 50% lethal doses of fmdv strain o1 campos. the following parameters were studied in recipient mice challenged with 10 0 ...	1984	6098985
purification and immunogenicity of fusion vp1 protein of foot and mouth disease virus.	a procedure has been developed to purify foot and mouth disease virus (fmdv) vp1 surface antigens from recombinant escherichia coli. the vp1 antigens are expressed as fusion proteins derived from the e. coli trp operon and vp1 surface protein of fmdv. the procedure is capable of recovering greater than 96% of the desired product at a purity of greater than 96%. the resulting antigens induce significant levels of virus-neutralizing antibody in guinea pigs and cattle as determined by a mouse prote ...	1984	6099140
mimicking foot-and-mouth disease virus antigens with synthetic peptides.		1984	6100728
biotechnological approach to a new foot-and-mouth disease virus vaccine.	major contributions towards the development of an absolutely safe fmdv vaccine are evident. with the identification of vp1 as the immunogenic protein, it is possible to manufacture a subunit vaccine via biotechnology. dna sequences encoding the vp1 protein can be introduced into a bacterium with ease; under the appropriate conditions, large amounts of vp1 can be produced in a short time. the accumulation of amino acid sequences generated by recombinant dna techniques allows identification of ant ...	1984	6085855
the effect of antiserum quality on strain specificity assessment of foot and mouth disease virus by the neutralization reaction.	the factors affecting the virus strain specificity of antibody to foot an mouth disease virus prepared by a variety of protocols in several species were evaluated by neutralization tests. the time at which the serum was taken, the antigen dose given, whether or not revaccination had occurred and the animal species in which the sera were prepared, did not appear to affect the strain specificity of serum prepared to inactivated antigens when measured in neutralization tests, probably because of th ...	1984	6090465
demonstration of neutralizing and non-neutralizing epitopes on the trypsin-sensitive site of foot-and-mouth disease virus.	the isolation of monoclonal antibodies directed against the trypsin-sensitive site on the 140s particle of foot-and-mouth disease virus (fmdv) has enabled the demonstration of at least three distinct epitopes within this site. reaction with two of these resulted in neutralization of virus infectivity. none of the epitopes appeared to be present on the 12s particles, and one of the neutralizing epitopes was sensitive to even milder configurational changes of the particle.	1984	6198448
evaluation of the antigenic variation within type-a foot and mouth disease virus isolates from asia.	the serological interrelationships among 17 type a fmd virus strains from eight asian countries were studied by the two-dimensional microneutralization test. complex direct and indirect relationships were observed. overall, however, the virus strains studied could be classified as belonging to the a22 group on the basis of r value differentiation at p less than 0.01.	1984	6203914
use of peptide synthesis to probe viral antigens for epitopes to a resolution of a single amino acid.	a procedure is described for rapid concurrent synthesis on solid supports of hundreds of peptides, of sufficient purity to react in an enzyme-linked immunosorbent assay. interaction of synthesized peptides with antibodies is then easily detected without removing them from the support. in this manner an immunogenic epitope of the immunologically important coat protein of foot-and-mouth disease virus (type o1) is located with a resolution of seven amino acids, corresponding to amino acids 146-152 ...	1984	6204335
epitopes on foot-and-mouth disease virus outer capsid protein vp1 involved in neutralization and cell attachment.	foot-and-mouth disease virus structural protein vp1 elicits neutralizing and protective antibody and is probably the viral attachment protein which interacts with cellular receptor sites on cultured cells. to study the relationships between epitopes on the molecule related to neutralization and cell attachment, we tested monoclonal antibodies prepared against type a12 virus, isolated a12 vp1, and a cnbr-generated a12 vp1 fragment for neutralization and effect on viral absorption. the antibodies ...	1984	6205165
localization of a neutralization epitope of foot-and-mouth disease virus using neutralizing monoclonal antibodies.	neutralizing monoclonal antibodies raised against intact foot-and-mouth disease virus reacted with intact particles and with isolated vp1 from different strains from the same subtype. prior treatment of the virus with either trypsin or with arginine-specific protease abolished recognition of both the virus and of vp1, suggesting the presence of a neutralization epitope in the central region of vp1 cleaved by these two enzymes. a synthetic peptide analogue of part of this region showed poor react ...	1984	6206202
chemical basis of antigenic variation in foot-and-mouth-disease virus.		1984	6208066
[trials to obtain conjugates for the passive hemagglutination test with chromium chloride and their use in studying foot-and-mouth disease viruses].	experiments were carried out to produce conjugates for the hemagglutination-inhibition reaction with the aid of chromic chloride. studies with reference f.m.d. viruses and with cft revealed that the antibody erythrocyte diagnostic agents were highly specific, and were stable in storage at +4 degrees c and in freeze-drying. it was found that the conjugates obtained with f.m.d. antigens possessed high specificity, however, were not stable and 7 to 10 days later lost their activity. tests with the ...	1984	6209849
nucleotide sequence of the vp1 gene of the foot-and-mouth disease virus strain a venceslau.	the vp1 coat protein of fmdv strain a venceslau (aven) consists of 213 amino acid residues. serum neutralization tests demonstrated that strain aven is closely related to strain a argentina/79 (a79) but significantly different from strain a24cruzeiro (a24). there is a strong correlation between the amino acid sequences and the serological data. nucleotide and amino acid sequence analyses of vp1 showed that serologically related viruses (aven and a79) differ less in this region of the genome than ...	1984	6096217
heterogeneity of the polyribocytidylic acid tract in aphthovirus: biochemical and biological studies of viruses carrying polyribocytidylic acid tracts of different lengths.	in this paper we report a study of a sample of foot-and-mouth disease virus carrying two polyribocytidylic acid [poly(c)] tracts of different lengths. by plaque purification in tissue culture, we isolated two populations of particles, one carrying the long poly(c) tract and the other carrying only the short homopolymer. the fingerprints of both viruses were indistinguishable from each other and from that of the virus present in the original sample, suggesting that the main difference between the ...	1984	6088803
location of neutralizing epitopes defined by monoclonal antibodies generated against the outer capsid polypeptide, vp1, of foot-and-mouth disease virus a12.	the epitopes of six monoclonal antibodies generated against type a12 foot-and-mouth disease virus (fmdv) vp1 or its largest cyanogen bromide fragment (13 kd) were characterized. five of these monoclonal antibodies neutralized viral infectivity. solid-phase and competitive antigen binding assays using virion-derived antigens or a biosynthetic vp1 polypeptide identified two distinct neutralizing epitopes. one epitope was located between amino acid residues 145-168 of vp1 and the other between amin ...	1984	6085200
selection of particles and proteins for use as human cytomegalovirus subunit vaccines.	uncertainties about the ultimate biologic consequences of using live virus vaccines to confer immunologic protection against cmv have focused attention on the use of noninfectious subunit vaccines. at least two classes of such preparations have been demonstrated to be effective in other systems. the first is virus particles bearing the relevant antigens but lacking nucleic acid (eg, hepatitis vaccine [31]). and the second class is biologically or chemically synthesized proteins or peptides with ...	1984	6329369
histone h3 modification in bhk cells infected with foot-and-mouth disease virus.	infection of bhk cells with foot-and-mouth disease virus (fmdv) causes a thorough change in the electrophoretic profile of whole nuclear histones. it consists in the disappearance of histone h3 and the appearance of a new polypeptide (pi) which migrates between histones h2a and h4 on sds-polyacrylamide gels. protein pi is detected at 2 hr postinfection (pi), the time in which viral rna synthesis begins to increase, and reaches equimolecular amounts with the remaining core histones 1 hr later, wh ...	1984	6330987
the complete nucleotide sequence of the rna coding for the primary translation product of foot and mouth disease virus.	the complete nucleotide sequence of the coding region of foot and mouth disease virus rna (strain a1061) is presented. the sequence extends from the primary initiation site, approximately 1200 nucleotide from the 5' end of the genome, in an open translational reading frame of 6,999 nucleotides to a termination codon 93 nucleotides from the 3' terminal poly (a). available amino acid sequence data correlates with that predicted from the nucleotide sequence. the amino acid sequence around cleavage ...	1984	6324120
guanidine-resistant poliovirus mutants produce modified 37-kilodalton proteins.	eighteen spontaneous, guanidine-resistant mutants of poliovirus were obtained by plaque selection. isoelectric focusing demonstrated charge changes in a 37-kilodalton protein, px, among three of the mutants. the precursor of px, ncvp5b , also exhibited charge changes among the three mutants. px of 12 mutants was also examined by peptide mapping with staphylococcus aureus v8 protease. nine of the mutants presented modified maps, and seven of these maps were identical. the demonstration of mutatio ...	1984	6328023
biologically active protease of foot and mouth disease virus is expressed from cloned viral cdna in escherichia coli.	foot and mouth disease virus o1k cdna had been cloned in escherichia coli. here we report on in vitro recombination of cdna fragments according to the cdna restriction map and on expression of viral proteins in e. coli. use was made of the expression vector pplvp1 , which is known to express the virus capsid protein vp1. recombined cdnas of various sizes were inserted downstream from the vp1 gene. the constructed plasmids differ from each other in the number of virus genes coding for nonstructur ...	1984	6328511
biochemical map of polypeptides specified by foot-and-mouth disease virus.	pulse-chase labeling of foot-and-mouth disease virus-infected bovine kidney cells revealed stable and unstable viral-specific polypeptides. to identify precursor-product relationships among these polypeptides, antisera against a number of structural and nonstructural viral-specific polypeptides were used. cell-free translations programmed with foot-and-mouth disease virion rna or foot-and-mouth disease virus-infected bovine kidney cell lysates, which were shown to contain almost identical polype ...	1984	6323757
formaldehyde inactivation of foot-and-mouth disease virus. conditions for the preparation of safe vaccine.	the inactivation of foot-and-mouth disease virus by formaldehyde was studied under different conditions, both as free virus and (as in routine vaccine production) after adsorption of the virus to aluminium hydroxide gel (alhydrogel). in the latter case infectivity was monitored after elution of the virus from the gel by isopycnic ultracentrifugation of the virus-alhydrogel mixture in cscl. by this method good virus recoveries were obtained. adsorption of the virus to alhydrogel (without formalde ...	1984	6326708
multiple proteases in foot-and-mouth disease virus replication.	translation of foot-and-mouth disease virus rna in a rabbit reticulocyte lysate for short time intervals resulted in the production of the peptides p20a , p16, and p88 (lab, lb, and p1) (r. r. rueckert , recommendations of the 3rd european study group on molecular biology of picornavirus, urbino , italy, 1983). if further translation was prevented, the structural protein precursor p88 was not cleaved, even after prolonged incubation. this result indicates that the mechanism of the cleavage betwe ...	1984	6328018
the thermal death time curve for foot-and-mouth disease virus contained in primarily infected milk.	whole and skim milk obtained from cows after intramammary and intravenous inoculation with foot-and-mouth disease virus (primarily infected milk) were exposed to various temperatures ranging from 80 to 148 degrees c for various times ranging from 2.5 s to 27 min then tested for viral infectivity. the average pretreatment titre of the 53 lots of milk used was 10(5.9) plaque-forming units of virus per millilitre 10(3.7)-10(6.8)). a thermal death time curve was plotted using the data obtained. the ...	1984	6330120
effect of lysosomotropic agents on the foot-and-mouth disease virus replication.	the effect of two lysosomotropic agents, nh4cl and chloroquine, on the foot-and-mouth disease virus (fmdv) replicative cycle was studied. when the drugs were present throughout the viral replicative cycle, an important inhibition of viral rna synthesis and virus production was detected. the inhibition of viral rna synthesis was maximal when the drugs were present from 30 min before virus infection up to 30 min after that. otherwise, if the agents were added once the viral synthesis has started ( ...	1984	6330983
relationship of human rhinovirus strain 2 and poliovirus as indicated by comparison of the polymerase gene regions.	cdna clones representing the 3'-terminal region of the human rhinovirus strain 2 genome have been obtained. the sequence of 1425 nucleotides adjacent to the poly(a) tract is presented and contains an open reading frame of 1383 nucleotides. the derived amino acid sequence corresponding to the putative rna polymerase-coding region is compared to those of poliovirus type 1 (mahoney) and foot-and-mouth disease virus a12. a high degree of homology between human rhinovirus strain 2 and poliovirus type ...	1984	6330989
in vitro morphogenesis of foot-and-mouth disease virus.	foot-and-mouth disease virion rna is translated efficiently and completely in a rabbit reticulocyte lysate cell-free system. treatment of cell-free lysates with monospecific serum prepared against the individual viral structural proteins or with monoclonal antibodies prepared against the inactivated virus or against a viral structural protein precipitated all of the structural proteins, suggesting that structural protein complexes were formed in vitro. sucrose gradient analysis of the cell-free ...	1984	6321761
the standardization of a 'spot-test' elisa for the rapid screening of sera and hybridoma cell products ii. the determination of binding capacity, binding ratio and coefficient of variation of different elisa plates in sandwich and indirect elisa.	the different commercially available enzyme-linked immunosorbent assay (elisa) plates were compared for their binding capacity for purified foot-and-mouth disease virus antigen or igg, their binding ratio (a measure of the efficiency with which positive and negative serum samples may be distinguished), and their coefficients of variation within a plate, between plates and between batches of plates. no one plate could be described as having ideal characteristics, and the choice of elisa plate dep ...	1984	6321511
homologous sequences in non-structural proteins from cowpea mosaic virus and picornaviruses.	computer analyses have revealed sequence homology between two non-structural proteins encoded by cowpea mosaic virus (cpmv), and corresponding proteins encoded by two picornaviruses, poliovirus and foot-and-mouth disease virus. a region of 535 amino acids in the 87-k polypeptide from cpmv was found to be homologous to the rna-dependent rna polymerases from both picornaviruses, the best matches being found where the picornaviral proteins most resemble each other. additionally, the 58-k polypeptid ...	1984	16453518
contribution of the "stefan s. nicolau" institute of virology to the electron microscopic study of viruses.	the review reflects the concerns of researchers of the "stefan s. nicolau" institute of virology who used electron microscopy techniques with a view to visualizing morphological features of virus structure (influenza, adeno, hepatitis, herpes, cytomegalic, aujeszky, rabies viruses, etc.) and different aspects of the virus - host cell relationships (sendai virus/hep2 cells, influenza and adenovirus/mouse lung, subacute sclerosing panencephalitis/human brain or cell cultures, coxsackie and foot-an ...	1984	6393566
serological response of guinea pigs to inactivated 146s antigens of foot and mouth disease virus after single or repeated inoculations.		1984	32987996
[development of a method for the quantitative determination of the immunizing antigen (140s) of the foot-and-mouth disease virus].	attempts were made to work out a method for measuring the amount of the 140 s antigen in virus suspensions. early postinfection sera were obtained from guinea pigs against the productional strains of the foot-and-mouth disease virus which were used in the radial immunodiffusion test. the investigated virus suspensions were concentrated 50 to 200 times and were placed in a cscl gradient for gradient centrifugation. the 140 s antigen fractions obtained were titrated in a radial immunodiffusion tes ...	1985	3002008
homologous interference by a foot-and-mouth disease virus strain attenuated for cattle.	an attenuated strain of foot-and-mouth disease virus (fmdv) of the a24 cruzeiro subtype grew less well than wild-type virus in primary bovine fetal kidney (pbk) cells resulting in a 4-log lowered efficiency of plaque formation. both wild-type and attenuated virus grew equally well in baby hamster kidney (bhk) cells and in suckling mice. using pbk cells, virus-specific rna of the wild-type accumulated up to 6 hours after infection. in contrast, pbk cells infected with the attenuated strain made l ...	1985	2415086
a liquid-phase elisa and its use in the identification of epitopes on foot-and-mouth disease virus antigens.	an enzyme-linked immunosorbent assay was developed which would detect antigen/antibody reactions in liquid-phase; that is under test conditions which should not alter the structure or reactivity of either antigen or antibody. this liquid-phase elisa was at least as efficient, both qualitatively and quantitatively, as the double sandwich or antigen-trapping elisa (crowther and abu elzein, 1979), but six to eight times more sensitive than the indirect elisa. the liquid-phase test can be used to as ...	1985	2414308
capsid intermediates assembled in a foot-and-mouth disease virus genome rna-programmed cell-free translation system and in infected cells.	structural protein complexes sedimenting at 140s, 70s (empty capsids), and 14s were isolated from foot-and-mouth disease virus-infected cells. the empty capsids were stable, while 14s complexes were relatively short-lived. radioimmune binding assays involving the use of neutralizing monoclonal antibodies to six distinct epitopes on type a12 virus and polyclonal antisera to a12 structural proteins demonstrated that native empty capsids were indistinguishable from virus. infected cell 14s particle ...	1985	2411948
small peptides induce antibodies with a sequence and structural requirement for binding antigen comparable to antibodies raised against the native protein.	antisera were raised against the chemically synthesized peptide corresponding to each epitope of three foot-and-mouth disease virus strains. peptide synthesis was further used to determine which amino acid residues in each epitope are important for the specificity of antisera raised against the whole virus. the specificity of the antibody paratope for its epitope was shown to depend on structure as well as sequence. anti-virus sera demonstrated a greater specificity for the homologous peptide th ...	1985	2578661
foot-and-mouth disease virus capsid proteins vp0, vp1 and vp3 synthesized by "in vitro" translation are the major components of 14s particles.	translation of foot-and-mouth disease virus rna in extracts of rabbit reticulocytes resulted in the synthesis and assembly of viral capsid protein into immature virion intermediate structures. the particles, which sedimented in the 14s zone of the sucrose gradient and contained only viral proteins vp0, vp1 and vp3 are believed to be pentameric associations of viral protomers.	1985	2869654
indirect immunofluorescence and immunodiffusion tests in the detection of antibodies to foot-and-mouth disease virus.	the antibody response detected by indirect immunofluorescence (iif) as well as that directed against 140 s and virus infection associated antigen (via), as detected by agar immunodiffusion, was studied in three mammal species susceptible to foot and mouth disease virus, after challenge with living virus, immunization and hyperimmunization with inactivated virus, and immunization followed by challenge. by spot indirect immunofluorescence, antibodies were detected only in animals undergoing an act ...	1985	2983488
[assays of cytotoxicity and antiviral activity of crude and semipurified extracts of green leaves of melia azedarach l].	crude extracts from fresh green leaves of melia azedarach l contain an antiviral factor (fav) able to inhibit the replication of several animal viruses, e.g. polio, vsv, hsv, fmdv, sindbis, junín, pichinde and tacaribe in vero or bhk-21 cells. crude preparations were subjected to different steps of purification like chromatography on sephadex g-100 and deae-sephadex. the antiviral activity of g-100 and deae fractions was fully conserved, whereas contaminating proteins were lost. two types of cyt ...	1985	2825236
a study of antigenic variants of foot-and-mouth disease virus by polyacrylamide gel electrophoresis of their structural polypeptides.	twenty-nine foot-and-mouth disease (fmd) type a virus strains, previously classified serologically as distinct subtypes were analysed by polyacrylamide gel electrophoresis (page) to determine the extent of variation in the pattern of the structural polypeptides and to evaluate the technique as an aid to existing subtyping techniques. the majority of the subtypes examined had distinct polypeptide patterns, however, some variation also occurred between strains within a subtype. the position of vp2 ...	1985	2412337
variation in foot-and-mouth disease virus isolates in kenya: an examination of field isolates by t1 oligonucleotide fingerprinting.	ribonuclease t1 oligonucleotide maps of strains of 4 of the endemic serotypes of foot-and-mouth disease virus isolated in kenya between 1964 and 1982 have been compared with data obtained in complement-fixation and neutralization tests. there was a continual change in the oligonucleotide maps obtained for all the serotypes examined. this genetic heterogeneity was generally associated with antigenic variation. viruses isolated during the 12-month course of an epidemic of the sat 1 serotype showed ...	1985	2413611
nonspecific immunostimulation against viruses.	a trypsinized preparation from chromogenic selected strain of mycobacterium phlei (nsi) stimulated the recipient immune system non-specifically against a variety of viruses viz. rabies virus (rna virus). marek's disease (dna virus) and foot and mouth disease virus (rna virus) in phylogenetically different hosts like mice, chicks and guinea pigs respectively. investigation into mechanisms of such nonspecific immunostimulation revealed that there was induction of strong cell mediated immune respon ...	1985	4064625
conditions for proper formaldehyde inactivation of foot and mouse disease alhydrogel vaccines.	the inactivation of fmdv by formaldehyde (fa) was studied under different conditions, both as free virus and (as in routine vaccine production) after adsorption of the virus to aluminium hydroxide gel (alhydrogel). in the latter case infectivity was monitored after elution of the virus from the gel by isopycnic ultracentrifugation of the virus-alhydrogel mixture in cscl. by this method good virus recoveries were obtained. adsorption of the virus to alhydrogel (without formaldehyde) did not reduc ...	1985	2995172
[use of muramyl dipeptides in models of synthetic vaccines].	vaccination represents a great success in clinical immunology and new approaches for designing vaccines of the future are now available. protective antigens could be obtained by recombinant dna technology or by synthesis. these new immunogens are likely to be poor immunogens and require the use of carrier and adjuvants. both carrier and adjuvant present some limitations. in this report we consider how synthetic glycopeptides analogous to muramyl dipeptide (mdp) can be used as adjuvants under sui ...	1985	3896261
foot-and-mouth disease virus subtype a22 epizootic in assam.		1985	2984834
[binary ethyleneimine as an inactivator of the foot-and-mouth disease virus].	experiments were carried out to inactivate f.m.d. viruses with the use of binary ethylene-imine. it was found that inactivation was optimal when the agent was used at the rate of 0.003 m for 18 hours at 26 degrees c. its neutralization in the virus suspension was carried out with 3 mm sodium thiosulfate. the inactivated f.m.d. viruses retained their complement-fixing and immunogenic properties. discussed are the advantages of using binary ethyleneimine as an inactivating agent as against other a ...	1985	2986348
nucleotide and amino acid sequence coding for polypeptides of foot-and-mouth disease virus type a12.	the coding region for the structural and nonstructural polypeptides of the type a12 foot-and-mouth disease virus genome has been identified by nucleotide sequencing of cloned dna derived from the viral rna. in addition, 704 nucleotides in the 5' untranslated region between the polycytidylic acid tract and the probable initiation codon of the first translated gene, p16-l, have been sequenced. this region has several potential initiation codons, one of which appears to be a low-frequency alternate ...	1985	2987518
detection of foot-and-mouth disease virus antibody using counterimmunoelectrophoresis and serum neutralisation tests.	a comparative investigation was made on the applicability, sensitivity and specificity of counterimmunoelectrophoresis (ciep) for the rapid detection of antibody to foot-and-mouth disease virus in cattle sera using as reference a standard serum neutralisation test. the ciep test was sensitive and exhibited a reasonable specificity.	1985	2992139
alteration in antibody reactivity with foot-and-mouth disease virus (fmdv) 146s antigen before and after binding to a solid phase or complexing with specific antibody.	this paper describes the reactions of a number of monoclonal antibodies produced against purified whole virions of foot-and-mouth disease virus in 3 different enzyme immunoassay systems. the first system used whole virus bound non-covalently to microplates; the second used whole virus trapped by a polyclonal antibody which was bound to microplates; and the third allowed the monoclonal antibodies to react with the whole virions in suspension (liquid phase) before trapping by the solid-phase-bound ...	1985	2993421
analysis of the secondary structure of the poly(c) tract in foot-and-mouth disease virus rnas.	sodium bisulphite modification of foot-and-mouth disease virus (fmdv) rna in solution indicates that the majority of the poly(c) tract in the rna is single-stranded in concordance with previous results with encephalomyocarditis virus rna. the reaction kinetics are biphasic; 60% of the cytidylic acid in the poly(c) tract reacts like synthetic poly(c), and the remainder with the kinetics of the cytidylic acid in the rest of the rna. the reactivity of the poly(c) tract with poly(i) indicates that i ...	1985	2993483
role of langerhans cells in the infection of the guinea-pig epidermis with foot-and-mouth disease virus.	in guinea-pig infected with foot-and-mouth disease virus (fmdv), langerhans cells in the foot pads increase in number and show viral antigens 24 hours post-inoculation, preceding appearance of virus in epithelial cells and vesiculation. this observation suggests that langerhans cells may be engaged in virus transport from the blood to the non vascularized epidermis.	1985	2982360
buffalo in the northern natal game parks show no serological evidence of infection with foot-and-mouth disease virus.	a total of 594 sera collected from buffalo (syncerus caffer) in the hluhluwe/umfolozi game reserve complex, ndumu game reserve and the eastern shores of lake st lucia were examined for antibody to sat 1, 2 and 3 types of foot-and-mouth disease (fmd) virus in neutralization tests. no neutralization of sat 2 or 3 viruses was exhibited by any of the sera tested at final dilutions greater than 10. a small proportion (2,9%) of sera neutralized sat 1 virus at dilutions up to 10, but these were conside ...	1985	2995896
biochemical characterization of an aphthovirus type 0(1) strain campos attenuated for cattle by serial passages in chicken embryos.	the biochemical properties of a virulent and an attenuated strain of foot-and-mouth disease virus (fmdv) type 0(1) campos (0(1)c) were compared in order to establish differences that could account for their altered biological functions. the avirulent strain (0(1)c-o/e) was derived from the virulent strain 0(1)c by serial passages in chicken embryos. analysis of the rnase t1-generated oligonucleotides of the viral rna through one- and two-dimensional (2d) gel electrophoresis (fingerprints) reveal ...	1985	2998071
immunological priming with synthetic peptides of foot-and-mouth disease virus.	a sub-immunizing dose of a synthetic peptide corresponding to the amino acids 141 to 160 region of protein vp1 from foot-and-mouth disease virus (fmdv), serotype o1, coupled to keyhole limpet haemocyanin (141-160klh) has been shown to prime the immune system of guinea-pigs for an fmdv serotype-specific neutralizing antibody response to a second sub-immunizing dose of the same peptide. optimal priming required an interval of 42 days between the priming dose and the booster dose. no priming was ob ...	1985	2997370
[an optical method for the quantitative detection of antibodies to foot-and-mouth disease virus--initial results].		1985	3000308
[behavior of foot-and-mouth disease virus in various density gradient media].		1985	3000312
radioimmunoassay for detection of vp1 specific neutralizing antibodies of foot and mouth disease virus.	a solid-phase radioimmunoassay was developed for the detection of antibodies against a specific region of the vp1 protein of the a24 and 01 serotypes of foot and mouth disease virus. the antibody titers from the radioimmunoassay showed a positive correlation with neutralizing antibody titers determined by a mouse protection assay. the specificity of the assay resides in the peptide used as antigen. the assay is rapid, reproducible and does not require the use of whole virions.	1985	2982892
sequence analysis of hepatitis a virus cdna coding for capsid proteins and rna polymerase.	we report here the nucleotide sequence corresponding to two large regions of the hepatitis a virus (hav) genome. these comprise a sequence of 3274 bases corresponding to the 5' end of the genome, which includes the putative capsid protein region of this picornavirus, and 1590 bases corresponding to the 3' end of the genome, terminating in a 15-base poly(a) tract. these sequences revealed that hav had the characteristic genomic organization of picornaviruses: an open reading frame beginning appro ...	1985	2984684
sequence variation in the gene for the immunogenic capsid protein vp1 of foot-and-mouth disease virus type a.	the nucleotide sequences have been determined and compared from cloned cdna genes coding for the foot-and-mouth disease virus (fmdv) immunogenic capsid protein, vp1, from eight different a subtypes: a5 westerwald/58, a12 119ab (large plaque variant), a22 550 ussr/65, a24 cruzeiro brazil/55, a27 cundinamarca colombia/76, a32 venezuela/70, a venceslau brazil/76, and a argentina/79. we have also found sequence variations among different cdna clones of the a5 and a24 subtypes. there are regions of n ...	1985	2986125
dose-response evaluation of a genetically engineered foot-and-mouth disease virus polypeptide immunogen in cattle.	four groups of 9 cattle each were vaccinated with 10, 50, 250, or 1,250 micrograms of foot-and-mouth disease (fmd) virus a12 vp1 fusion protein that was produced in escherichia coli and emulsified in an oil adjuvant. the groups given the 10 and 50 micrograms of antigen were revaccinated at 15 weeks and were challenge exposed at 30 weeks; 5 of 9 and 7 of 9 cattle, respectively, were protected from fmd virus infection. the remaining 2 groups, vaccinated with 250 or 1,250 micrograms of antigen, wer ...	1985	2986495
effect of salts and other agents on foot-and-mouth disease virus poly (u) polymerase activity.	the activity of the purified poly(u) polymerase replication complex of foot-and-mouth disease virus was optimized when 100 mm nh4+ and either 0.75 mm al3+ or 1.0 mm fe3+ was added to the standard assay reaction mixture. zn2+ at concentrations of 10(-5) mm to 5 mm inhibited enzyme activity although all polymerases examined to date have contained zinc. mercaptoethanol and dithiothreitol inhibited polymerase activity despite the presence of cysteine residues in the viral induced polypeptide of the ...	1985	2986581
evaluation of methods for chemically coupling foot-and-mouth disease virus to sheep red blood cells for immunological assays.	six methods of chemically coupling proteins to red blood cells were evaluated for their effectiveness in coupling foot-and-mouth disease virus (fmdv) to sheep red blood cells. the coupling agents tested were potassium periodate, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (ecdi), chromium chloride, glutaraldehyde, bis-diazotized benzidine (bdb) and n-succinimidyl 3-(2-pyridyldithio) propionate (spdp). of these, only the coupling methods using bdb and spdp resulted in virus-red c ...	1985	2991312
isolation and biochemical characterization of intertypic recombinants of foot-and-mouth disease virus.	recombinants were isolated between two european serotypes (o and a) and between two of the most distantly related serotypes (o from europe and sat2 from africa) using appropriate ts mutants in an infectious centre assay. the recombinants were characterised by electrofocusing of their induced proteins and by rnase-t1 fingerprinting of their rna. the approximate location of the cross-over event in each recombinant was determined by sequencing the unique distinguishable o or a oligonucleotides and ...	1985	2992184
establishment of cell lines persistently infected with foot-and-mouth disease virus.	cell lines persistently infected with foot-and-mouth disease virus (fmdv) have been established by growth of bhk-21 (c-13) or ibrs-2 (c-26) that survived standard cytolytic infections with fmdv. they maintain cytoplasmic fmdv rna sequences, as shown by dot blot hybridization tests, using cloned fmdv cdna as probes. cell line c1-bhk-rc1 was derived by infection of cloned bhk-21 c1 cells and plaque-purified fmdv c-s8 c1. indirect immunofluorescence assays indicated the presence of fmdv antigens. i ...	1985	2990100
sequence of the viral replicase gene from foot-and-mouth disease virus c1-santa pau (c-s8).	the nucleotide sequence of the region including the viral replicase gene, the carboxy terminus of protein p18, and the 3'-extracistronic region of foot-and-mouth disease virus (fmdv) type c1-santa pau (c-s8) has been determined from previously cloned cdna fragments [villanueva et al., gene 23 (1983) 185-194]. the comparison with the corresponding gene segments of fmdv of serotypes a or o shows base substitutions in 7.2-8.6% of residues in the replicase gene with no insertions or deletions. this ...	1985	2993105
structure of a human common cold virus and functional relationship to other picornaviruses.	we report the first atomic resolution structure of an animal virus, human rhinovirus 14. it is strikingly similar to known icosahedral plant rna viruses. four neutralizing immunogenic regions have been identified. these, and corresponding antigenic sequences of polio and foot-and-mouth disease viruses, reside on external protrusions. a large cleft on each icosahedral face is probably the host cell receptor binding site.	1985	2993920
an international collaborative study on foot and mouth disease virus assay methods. 2. quantification of 146s particles.	workers in 11 laboratories in europe and one in north america participated in a collaborative study to assess the variability of a sucrose gradient procedure used for the quantification of foot and mouth disease virus (fmdv). to this end, a range of standards was distributed from one of the participating laboratories. a series of adenine preparations were used to assess the various spectrophotometers/uv monitors and it showed most to be accurate and linear in their responses. the fmdv and ms2 ri ...	1985	2997228
foot-and-mouth disease virus-induced rna polymerase is associated with golgi apparatus.	electrophoretic analysis of the golgi apparatus isolated by differential centrifugation from radiolabeled cells infected with foot-and-mouth disease virus showed about 10 protein bands. the virus-induced rna polymerase was identified by immunoprecipitation and electron microscope staining procedures. pulse-chase experiments indicated that the polymerase passed through the golgi apparatus in less than 1 h.	1985	2997481
early steps in fmdv replication: further analysis on the effects of chloroquine.	we have previously demonstrated that chloroquine and nh4cl, two well-known lysosomotropic drugs inhibit foot-and-mouth disease virus (fmdv) replication. this fact points to the relevance of an acidic environment during fmdv penetration. in the present report, we show that chloroquine prevents the cell-mediated disruption of 140 s virions into 12 s particles. this dissociation, which resembles that caused by low ph in vitro, might be an initial uncoating step. furthermore, we demonstrated that a ...	1985	2998059
two initiation sites for foot-and-mouth disease virus polyprotein in vivo.	typically, the translation of eukaryotic mrnas into protein is initiated at a single site. however, we have recently shown that not one but two primary products, p20a and p16, are translated from the 5' end of the coding region of the genome of foot-and-mouth disease virus (fmdv). in this paper we show by partial protease digestion of these proteins that they differ only at their n termini, thus confirming the presence of two initiation sites for translation of fmdv rna. sequence analysis of two ...	1985	2999308
recombination and oligonucleotide analysis of guanidine-resistant foot-and-mouth disease virus mutants.	guanidine resistance (gr) mutations of foot-and-mouth disease virus were mapped by recombining pairs of temperature-sensitive mutants belonging to different subtypes. in each cross, one parent possessed a gr mutation. recombinants were isolated by selection at the nonpermissive temperature and assayed for the ability to grow in the presence of guanidine. from the progeny of three crosses, four different types of recombinant were distinguished on the basis of protein composition and rna fingerpri ...	1985	2999445