Publications

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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
[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
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
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
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
[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
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
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
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
mimicking foot-and-mouth disease virus antigens with synthetic peptides.		1984	6100728
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
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
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
serological response of guinea pigs to inactivated 146s antigens of foot and mouth disease virus after single or repeated inoculations.		1984	32987996
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 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
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
transformation and foot and mouth disease virus (fmdv) productivity of some bhk cell lines.		1983	6140842
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
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
studies on the stability of foot-and-mouth disease virus using absorbance - temperature profiles.	the main immunogenic component of fmd virus harvests is the intact 140s virus particle. for the production of stable vaccines it is important to ensure that virus strains having a stable capsid should be used. the method of measuring the heat stability of fmd virus by following the increase in optical density of purified virus during capsid breakdown as the temperature is increased was described in 1964 (p. bachrach, 1964, j. mol. biol 8. 348). we have investigated this technique in the hope tha ...	1983	6329854
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
physicochemical transformation of milk components and release of foot-and-mouth disease virus.	possible mechanisms for protective roles of milk components on foot-and-mouth disease virus present in the milk of infected cows were examined. light scattering bands collected from ficoll-sucrose gradient fractions of skim-milk contained membrane-limited structures but these were non-infectious for bovine kidney cells. infectivity titres in buttermilk higher than those of the original cream or butter suggested association of virus with milk fat globules. increased infectivity titres in skim-mil ...	1983	6302144
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 amino acid and nucleotide sequence of the foot-and-mouth disease virus rna polymerase.	foot-and-mouth disease virus (fmdv) rna polymerase was purified from the polyethylene glycol (peg)-treated supernatant of infected cell media by a combination of ion-exchange chromatography, membrane molecular filtration, and affinity chromatography. the purified rna polymerase which migrated as a single band of 56,000 molecular weight on a polyacrylamide gel was subjected to automated edman degradation and the sequence of the first 30 amino acid residues established. on the basis of previous ev ...	1983	6305004
multiple homologies of oligonucleotide size exist between nucleic acids of picornaviruses.	a semi-quantitative analysis of hybrid formation between restriction enzyme-generated subgenomic fragments of cloned cdna prepared from rna of foot-and-mouth disease virus (fmdv) strain o1k and radiolabelled rna from bovine enterovirus, bovine rhinovirus or mengo virus indicated that the hybrids were of oligonucleotide size. they were located in those parts of the fmdv o1k genome that code for the two capsid proteins vp3 and vp1 and the precursor protein p52 as well as at the 3' end. no hybridiz ...	1983	6306155
an attempt at preparing anti-foot-and-mouth disease virus serum.		1983	6306318
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 improvement and standardization of the simplified process for the production of foot and mouth disease virus from bhk suspension cells.	improvements have been made to the methodology for the production of foot and mouth disease (fmd) virus from bhk 21 clone 13 suspension cells by the simplified process. data derived from some 600 individual 8-1 cultures covering all seven types of fmd virus has been analysed. the production of virus was shown to (1) have no direct relationship to cell passage level and (2) to be inversely related to the cell multiplication factor observed during the cell growth cycle immediately prior to infecti ...	1983	6309847
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
multiple genetic variants arise in the course of replication of foot-and-mouth disease virus in cell culture.	the genetic heterogeneity generated upon passage of foot-and-mouth disease virus (fmdv) in cell culture has been evaluated by t1-oligonucleotide fingerprinting of genomic rna. plaque-purified fmdv o-s7 and c-s8 were propagated by serial low multiplicity infections of bhk-21 (c-13) or ibrs-2 (c-26) cells. in independent parallel passage of the same virus, different oligonucleotide variations were fixed in the rnas. t1-oligonucleotide fingerprinting of rna from 34 individual viral clones derived f ...	1983	6310859
molecular cloning of cdna from foot-and-mouth disease virus c1-santa pau (c-s8). sequence of protein-vp1-coding segment.	cdna segments copied from the rna of foot-and-mouth disease virus (fmdv) c1-santa pau (isolate c-s8) have been cloned in plasmid pbr322. a 998-bp dna fragment, that includes the region coding for capsid protein vp1, the carboxy terminus of vp3, and the amino terminus of precursor protein p52 has been sequenced. comparison of the nucleotide sequence with those from fmdv o1k, a(10)61, a12 and c3 indaial (kurz et al., nucl. acids res. 9 (1981) 1919-1931; kleid et al., science 214 (1981) 1125-1129; ...	1983	6311686
histological and histochemical characterisation of mammary gland tissue of cows infected with foot-and-mouth disease by contact exposure.	foot-and-mouth disease virus was observed to replicate in secretory epithelial cells of bovine mammary gland alveoli as a result of systemic infection initiated by exposure to infected animals. viral antigens were demonstrated using fluorescent antibody and immunoperoxidase labelling techniques before the development of signs of clinical disease. in addition, labelled antigens were observed associated with cytoplasmic-like fragments in luminal membrane limited structures. histologically, lesions ...	1983	6312518
[passive hemagglutination reaction in differentiating foot-and-mouth disease viruses].	experiments were carried out with the use of the passive hamagglutination reaction in the differentiation of foot-and-mouth disease viruses. the investigations made use of purified sera and specific igg antibodies obtained through column chromatography. conjugates were prepared with the use of bis-diazotized benzidine and glutaraldehyde. in experiments with conjugates prepared with igg and glutaraldehyde standard and reproducible results were obtained. the use of the passive hemagglutination tes ...	1983	6312672
cross antigenicity among enteroviruses as revealed by immunoblot technique.	antigenic relationships of various human and two animal picornaviruses were investigated by the immunoblotting ("western blot") technique. the viruses included all coxsackievirus b types (1-6), poliovirus types 1-3, several strains of echovirus 11, emc virus, and fmdv. antisera included human sera and sera from rabbits hyperimmunized with either purified picornaviruses, viral structural polypeptides (vp8), boiled or "sample-boiled" virions. group-specific reactions of various extent were observe ...	1983	6312682
association of foot-and-mouth disease virus induced rna polymerase with host cell organelles.	the localization of foot-and-mouth disease viral-induced rna polymerase has been determined in situ and in partially fractionated cell components by using polymerase antisera tagged with either peroxidase or ferritin. electron microscopic examination revealed the polymerase to be heavily concentrated on membranes of the smooth membranous vacuoles (smv) which are newly formed during infection and which were previously shown to be the site where newly synthesized viral rna appeared. polymerase ant ...	1983	6313290
gene fusions using the ompa gene coding for a major outer-membrane protein of escherichia coli k12.	it has been shown previously that fragments of the escherichia coli major outer membrane protein ompa lacking co2h-terminal parts can be incorporated into this membrane in vivo [bremer et al. (1982) eur. j. biochem. 122, 223-231]. the possibility that these fragments can be used, via gene fusions, as vehicles to transport other proteins to the outer membrane has been investigated. to test whether fragments of a certain size were optimal for this purpose a set of plasmids was prepared encoding 16 ...	1983	6313361
the attachment of the foot-and-mouth disease virus asia i iran 1/73 to bhk suspension cells does not require virus specific cell receptors.	experiments are described which show that a member of the picornaviridae (fmd virus asia i iran 1/73) attaches to bhk suspension cells in a manner which precludes a requirement for virus specific receptors on the cell plasma membrane. while it may be possible to demonstrate the apparent saturation of the cell surface with multiple doses of virus, an increase of the concentration of the dosing suspension results in more virus attachment. indeed, it was found that with the amounts of virus which w ...	1983	6314941
innocuity testing of foot-and-mouth disease vaccines. ii. aziridine-inactivated antigen produced in baby hamster kidney cells.	methods for the testing of preparations of aziridine-inactivated foot-and-mouth disease virus for the absence of infective particles were studied. the system used for virus production, suspension cultures of baby hamster kidney cells, proved to be the most sensitive detection system for traces of infective virus as long as the 146s antigen concentration was below 1 microgram per 10(6) cells. above this level interference may mask the presence of non-inactivated virus. thus in a 1-1 suspension cu ...	1983	6315737
aerosol exposure of cattle to foot-and-mouth disease virus.	slight modifications of a small, plastic covered greenhouse provided a chamber for the exposure of cattle of all ages to aerosols of foot-and-mouth disease virus. particle size distributions of aerosols were 76% less than 3 microns, 17% 3-6 microns, and 7% greater than 6 microns immediately after the devilbis no. 40 nebulizer used was turned off and 90% less than 3 microns, 8% 3-6 microns, and 2% greater than 6 microns 20-30 min later. pharyngeal virus growth curves and viremia patterns correlat ...	1983	6315813
structure of the fmdv translation initiation site and of the structural proteins.	a cdna clone of foot and mouth diseases virus (fmdv), strain c1, has been sequenced. the limits of the structural genes were defined by comparison with the available protein data. we identified two potential translation initiation sites for the viral polyprotein separated by 84 nucleotides. we suggest that these two initiation sites could be used to express two proteins differing only at the n-terminal, p16 and p20a. this model is supported by the fact that antiserum against a bacterially synthe ...	1983	6316275
isolation of capsid proteins of foot-and-mouth disease virus by chromatofocusing.	a method for the isolation of foot-and-mouth disease virus (fmdv) capsid proteins was developed. the fmdv capsid proteins vp1, vp2, vp3 and vp0 were isolated from sucrose gradient purified virus by chromatofocusing in a ph 7.4-4.0 gradient on polybuffer exchanger pbe 94. under the conditions used the proteins eluted in the sequence vp1, vp2, vp0 (when present) and vp3. capsid protein vp4 did not elute and could not be isolated by this method. protein concentration in the eluate was monitored by ...	1983	6317707
chemical basis of antigenic variation in foot-and-mouth disease virus.	one of the difficulties in controlling foot and mouth disease by vaccination is the occurrence of the virus as seven distinct serotypes because immunity conferred by vaccination against one serotype leaves the animals susceptible to infection by the other six. moreover, the antigenic variation, even within a serotype, can be so great that immunity against the homologous strain of virus need not necessarily ensure protection against infection by other viruses within that serotype. here we report ...	1983	6318114
a serological and biochemical study of new field isolates of foot-and-mouth disease virus type a in peru, 1975 to 1981.	three foot-and-mouth disease virus type a isolates recovered from field outbreaks in the department of san martin, peru, during the period 1975 to 1981 were compared with each other, and the south american vaccine strains a24 and a27, by complement fixation (cf), virus neutralization (vn) and polyacrylamide gel electrophoresis (page). complement fixation and vn tests gave comparable results distinguishing the field isolates from each other and from the vaccine strains. analysis of the structural ...	1983	6318421
[comparative testing of the quality of foot-and-mouth disease vaccines prepared with different virus inactivators].	formalin, glycidaldehyde, and the binary ethyleneimine were tested under laboratory conditions as inactivators of the foot-and-mouth disease virus along with the possibility of using them in the process of vaccine production. data is presented on the comparative testing for innocuity and immunogenicity for sheep of f. m. d. vaccines produced with such inactivators. results showed the advantages of the binary ethyleneimine as against formalin and glycidaldehyde as an inactivator of the f. m. d. v ...	1983	6318423
use of short analytical ultracentrifugation runs for the isopycnic determination of foot-and-mouth disease virus concentration and density in autoformed caesium chloride gradients.	short analytical ultracentrifugation runs of less than six hours with autoformed cscl density gradients were used for routine fmdv density and concentration analysis. the values obtained after short runs were slightly higher for concentration and lower for density than after classical 22 h runs. these differences between the 6 and the 22 h values were related to virus strain and did not seem to result of the incomplete stabilisation of the cscl gradient, but of the shorter virion/cscl contact pe ...	1983	6318644
correlation of surface and internal ultrastructural changes in cells infected with foot-and-mouth disease virus.	the surfaces of primary and continuous line cell cultures displayed the same sequence of morphological changes during the course of infection with foot-and-mouth disease virus. these changes could be classified into four broad stages: i) cells were flattened, closely attached to one another and microvilli appeared, ii) cells rounded, microvilli began to disappear and the cells started to separate from one another by cytoplasmic strands, iii) cells were discrete, rounded structures and iv) cells ...	1983	6321000
using genetically engineered bacteria for vaccine production.	we concluded from this and our earlier work that biosynthetically produced fmdv vp1-specific fusion proteins are effective vaccines. whether this method of vaccine production can be extended to many other immunogenic proteins from other organisms is not known. some problems that could be expected to occur with bacterially produced antigens are that the immunogenic site may not be properly exposed or the peptide sequence(s) within that site may not be able to form into the correct configuration. ...	1983	6322643
protective role of foot-and-mouth disease virus antibody in vitro and in vivo in guinea-pigs.		1983	6834003
herpes type 2 infection with unusual generalised manifestations and delayed diagnosis in an adult male.	a case of severe generalised herpes simplex type 2 infection is described in an adult male who had known exposure to herpes. the patient first complained of headache, fever and neurological symptoms, and three to six days later of conjunctivitis, severe pharyngitis, arthralgia and vesicular lesions about the body. during the first 14 days of illness, including three in hospital, the patient was diagnosed as having infection with varicella virus, vesicular stomatitis virus, or hand-foot-and-mouth ...	1983	6875292
comparison of the amino acid sequence of the major immunogen from three serotypes of foot and mouth disease virus.	cloned cdna molecules from three serotypes of fmdv have been sequenced around the vp1-coding region. the predicted amino acid sequences for vp1 were compared with the published sequences and variable regions identified. the amino acid sequences were also analysed for hydrophilic regions. two of the variable regions, numbered 129-160 and 193-204 overlapped hydrophilic regions, and were therefore identified as potentially immunogenic. these regions overlap regions shown by others to be immunogenic ...	1982	6298715
ultrastructural changes and antigen localization in tissues from foot-and-mouth disease virus-infected guinea-pigs.	foot-and-mouth disease virus (fmdv)-induced ultrastructural changes in guinea-pig tongue, heelpad, mammary and liver tissues were examined using scanning and transmission electron microscopy. fmdv infection caused cell rounding and the release of virus in membrane limited vesicles in the animal tissues similar to that seen in other work in cell cultures. microfilaments were present which may be responsible for cell rounding. immunoperoxidase labeling revealed the attachment of the virus-infectio ...	1982	6298989
genetically engineered viral vaccines--prospects for the future.	genetic engineering (recombinant dna technology)--the revolution in molecular biology--has enabled us to isolate any genes from any source in a pure form, and to move them from one cell to another. it has become possible to program bacterial or yeast cells with foreign genes and force the new host to produce commercially valuable proteins (e.g. hormones, enzymes, diagnostic reagents). it is now also possible to produce viral and bacterial antigens in various types of cells. we hope that this wil ...	1982	6763495
long distance transport of foot-and-mouth disease virus over the sea.	the conditions required for the transport of foot-and-mouth disease (fmd) virus in the atmosphere over long distances and in sufficient concentrations to cause infection in exposed animals are described. using these factors a series of 23 outbreaks of fmd in europe, where the original outbreaks were separated from later outbreaks by sea passage, have been investigated. the findings obtained support the hypothesis that under certain conditions the airborne transmission of fmd over a long sea pass ...	1982	6278697
cores in foot-and-mouth disease virus.		1982	6278713
the adsorption and degradation of foot-and-mouth disease virus by isolated bhk-21 cell plasma membranes.		1982	6278720
application of rnase t1 one- and two-dimensional analyses to the rapid identification of foot-and-mouth disease viruses.	the analysis of several isolates of foot-and-mouth disease virus by rnase t1 fingerprinting of the 32p-labeled rna is described. it has been shown that use of the 35s induced rna instead of the virus particle rna has two advantages. (i) about 40 times more radioactivity is incorporated into the induced rna. (ii) the rna can be prepared much more rapidly, thus increasing the value of the technique in rapid diagnosis. one-dimensional maps, in which the rnase t1 oligonucleotides are separated accor ...	1982	6281186
three strains of european foot-and-mouth disease virus are highly conserved in the 3'-termini and highly variable in the genes of two capsid proteins.	restriction enzyme-generated subgenomic fragments of cloned cdna prepared from rna of the strain o1 kaufbeuren (o1k) of foot-and-mouth disease virus (fmdv) were compared qualitatively and quantitatively for sequence complementarity with radioactive rna from strains c oberbayern (cobb) and a2 spain (a2s) in hybridization experiments on nitrocellulose membranes. quantitative comparison of nucleic acid sequences neighbouring (c obb/o1k) or including (a2s/o1k) the 3' end of the virus genomes demonst ...	1982	6281370
the nucleotide sequence of cdna coding for the structural proteins of foot-and-mouth disease virus.	the complete nucleotide sequence of cdna coding for the structural capsid polypeptides of foot-and-mouth disease virus (fmdv) (strain a(10)61) has been determined. portions of the flanking sequence coding for the nonstructural proteins p20a and p52 are also provided. the three larger structural polypeptides vp1, vp2 and vp3 have unmodified mrs of 23248, 24649 and 24213, respectively. the size of the smaller polypeptide, vp4, can only be estimated at 7360 because the 5'-limit of its coding region ...	1982	6282711
differentiation of foot-and-mouth disease virus strains using a competition enzyme-linked immunosorbent assay.	foot-and-mouth disease virus isolates were compared using solid-phase competition and indirect microenzyme-linked immunosorbent assays. results were compared to those obtained from complement fixation tests. similar relationships between the isolates were obtained using the indirect enzyme immunoassay and complement fixation tests. the competition assay was more discriminatory and the results did not always correlate with the other two assays.	1982	6282918
immunosuppression in bovine trypanosomiasis: response of cattle infected with trypanosoma congolense to foot-and-mouth disease vaccination and subsequent live virus challenge.	the primary and secondary antibody responses to foot-and-mouth disease virus vaccine were examined in cattle infected with trypanosoma congolense and the response of some of these animals to live foot-and-mouth disease virus challenge was assessed. infected groups of cattle had rather lower antibody responses than uninfected control cattle after primary vaccination but the antibody titres were not significantly depressed until after secondary vaccination. these levels remained depressed for the ...	1982	6285433
foot-and-mouth disease virus: immunogenicity and structure of fragments derived from capsid protein vp and of virus containing cleaved vp.	peptide fragments were obtained from the immunogenic capsid protein vp3, ca. 24 kilodaltons (kd), of foot-and-mouth disease virus type a12 119ab by three procedures: (1) spontaneous proteolysis of in virion vp3 in tissue cultures to produce a 15 kd peptide, designated s fragment; (2) trypsin treatment of purified virus to produce a 16 kg peptide, designated t fragment; and (3) cyanogen bromide cleavage of purified vp3 to produce a 13 kd fragment. following isolation and purification by gel elect ...	1982	6287701