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indirect complement fixation test with foot-and-mouth disease virus antigen concentrated by polyethylene glycol precipitation.to a bhk-21 cell culture fluid infected with the o, a, or asia 1 type of foot-and-mouth disease (fmd) virus was added polyethylene glycol 16000 to a concentration of 10% (w/v). then the fluid was concentrated to one-tenth of the original volume. the resulting concentrated virus antigens showed a complement fixation (cf) titer ranging from 12 to 14. the rate of recovery of cf activity was in a range of 40 approximately 80%. each antigen was applied to the indirect complement fixation (icf) test w ...1978206842
isolation of foot-and-mouth disease virus from yak. 1978207010
more precise location of the polycytidylic acid tract in foot and mouth disease virus rna.the polycytidylic acid [poly(c)] tract in foot and mouth disease virus rna has been located about 400 nucleotides from the 5' end of the rna by analysis of the products from the digestion of the rna with rnase h in the presence of oligodeoxyguanylic acid [oligo(dg)]. this treatment produces a small fragment (s) containing the small protein covalently linked to the rna and a large fragment (l) that migrates faster than untreated rna on low-percentage polyacrylamide gels, lacks the poly(c) tract a ...1978207892
effect of zinc and other chemical agents on foot-and-mouth-disease virus replication.chemical agents reported to inhibit the growth of various ribonucleic acid and deoxyribonucleic acid viruses were tested against foot-and-mouth disease virus in cell culture. these included zn(2+), aurintricarboxylic acid, polyribocytidylic acid, polyriboinosinic acid, phosphonoacetic acid, and the viral contact inactivator n-methyl isatin beta-thiosemicarbazone alone and with cuso(4). the most effective agent, zn(2+), inhibited foot-and-mouth disease virus production in primary calf kidney cell ...1978208461
ribonuclease activities associated with purified foot and mouth disease virus.ribonuclease activities internally and externally associated with purified foot-and mouth disease virus were detected. the outer activity was easily removed by cesium chloride or by detergent (sarkosyl). the inner activity is not removable by any procedure used and could be the enzyme responsible for the heterogeneity normally observed in the extracted fmdv-rna. it is not known at present if both activities are related to the same or to different enzymes.1978208488
secretory antibody responses in cattle infected with foot-and-mouth disease virus.antibody responses in serum, saliva, nasal secretions, or esophageal-pharyngeal fluid of foot-and-mouth disease virus-infected steers were examined by single radial immunodiffusion and mouse-neutralization tests. in steers infected with type o foot-and-mouth disease virus, high serum antibody titers were detected within 10 days after infection. antibody was first detected in saliva at 30 days and gradually increased to a plateau at about 90 days. small amounts of antibody continued to be secrete ...1978209706
foot and mouth disease virus. ii. endoribonuclease activity within purified virions. 1978210581
the detection of antibody to virus-infection associated (via) antigen in various species of african wildlife following natural and experimental infection with foot and mouth disease virus.the double immuno-diffusion (did) test has been applied to detect antibody to via antigen in sera from various species of african wild ungulates. in conjunction with the serum neutralisation (sn) test it can be used to decide the degree of risk of movement of animals to other countries free from foot and mouth disease (fmd). the value of the test in assessing the history of infection is limited by its relatively low sensitivity and specificity in respect of virus type.1978210744
microneutralization tests for serological typing and subtyping of foot-and-mouth disease virus strains.a microneutralization test for serotyping of fmd viruses is described. it is based on earlier observations by booth, rweyemamu & pay (1978) that dose-response relationships in quantal microneutralizations often deviated from linearity. the typing test described therefore utilizes undiluted virus preparations. in about 90% of samples a positive typing was obtained in contrast with about 50% for the complement fixation test. the test was also found to be susceptible to minimal quantities of hetero ...1978211160
[use of ultrasonics in purifying the aphthous foot-and-mouth disease virus]. 1978211705
[radial immunodiffusion reaction in research with the foot-and-mouth disease virus]. 1978211706
differentiation between specific and nonspecific reactions of bovine sera and foot and mouth disease virus (fmdv) in immunodiffusion tests.the precipitating and neutralizing activities of normal bovine sera with fmdv were studied and compared. twenty-two out of 79 normal bovine sera gave a positive reaction in micro neutralization tests with fmdv type o, while six did so with type a. in rid tests 32 sera were positive with type o and 28 with type a virus. almost all of the 79 sera gave a positive reaction in the rid with trypsin treated virus of both types. after three to four fold concentration most sera also gave visible reaction ...1978211990
preadsorption of boar semen with kaolin: increased efficiency of foot-and-mouth disease virus detection.the boar semen-associated cytotoxic factor(s), but not the antiviral activity, were removed by adsorption with kaolin. although foot-and-mouth disease virus was efficiently removed from medium by kaolin or kieselguhr, the virus was not removed from semen-virus mixtures. because the cytotoxicity induced by boar semen apparently altered the ability of tissue culture cells to support virus replication, preadsorption with kaolin increased the probability of detecting this virus in semen samples.1978213994
[determination of the amount of the 140s-component of foot-and-mouth disease virus]. 1978214930
excretion of foot-and-mouth disease virus in oesophageal-pharyngeal fluid and milk of cattle after intranasal infection.the virus growth in the pharyngeal area and the virus excretion in milk of susceptible and vaccinated dairy cows after intranasal instillation of foot-and-mouth disease (fmd) virus type o1 were examined. ten vaccinated cows were purchased through a market. of these, nine had delivered their first calf. the cows were inoculated 2-9 months after having received the last dose of vaccine. all vaccinated cows resisted the intranasal challenge. the virus multiplied in the pharyngeal area but, compared ...1978215675
inactivated-concentrated virus antigen for indirect complement fixation test of foot-and-mouth disease.to the culture fluids of bhk-21 cells infected with each of types o, a, and asia 1 of foot-and-mouth disease virus was added acetylethyleneimine to 0.05% (v/v). the mixtures were incubated at 37 degrees c for 24 hours. to them were then added polyethylene glycol 6000 to 10% (w/v), and the mixtures concentrated to one-tenth of the initial volume. the resulting inactivated-concentrated virus antigens showed a complement fixation (cf) titer ranging from 12 to 24. the recovery rate of cf activity wa ...1978216926
the n-terminal sequence of three coat proteins of foot-and-mouth disease virus. 1978217392
[micromethod of determining the complement-binding properties of commercial series of the foot-and-mouth disease virus].investigations were carried out to establish the possibility of using a micromethod of the complement-fixation test to determine the complement-fixing properties of productional series of the foot-and-mouth disease virus. it was found that the micromethod referred to is an economically profitable and practically simple one. it is readily applicable requiring no particular apparatuses and equipment, is specific, and can successfully be used instead of the routinely employed cft method. the microm ...1978218334
[serologic study of 2 strains of foot-and-mouth virus, cultured in cell line ib-rs-2, clone 26-3].the antigenic characteristics of the two fmdv plaque size variants asq-pg and asq-pp were studied by serum neutralization kinetics. the results evidentiated that the antiserum asq-pg and asq-pp neutralized both variants at the same extent. the plaque population of these variants after passage in laboratory animals was compared in ib-rs-2 cells.1978224836
[effect of hormones on the susceptibility of the swine cell line ib-rs-2 to foot-and-mouth disease virus].the actions of hydrocortisone and insulin on the multiplication of foot-and-mouth disease virus were studied. the data obtained showed that the infectivity and the synthesis of the virus nucleic acid as evaluated through the plaque assay method and the kinetics of uridine-3h incorporation were increased or decreased by hydrocortisone (2 x 10(-6) m). the induction of both effects seems to be related to the carbohydrate metabolism: when the maintenance medium contained glucose or glucose plus calf ...1978224839
[isolation of foot-and mouth disease virus in swine with other diseases].the authors took a survey of foot-and-mouth disease samples of myocardium and tonsil from swine which was died without clinicals signs of foot-and-mouth disease, with isolation of virus, type o, a and c. it was observed and accentuated relation between the incidence of hog cholera, pneumonia and atipic foot-and-mouth disease, especially from suckling pigs.1978224841
[effects of polyionic compounds in the plaque formation of different strains of foot-and-mouth disease virus (fmdv) in the swine cell line ib-rs-2].the effects of dithylaminoethyl (deae)-dextran (dd) and dextran-sulfate (ds) were studied in some strains of the foot-and-mouth disease virus (fmdv). the strains asq-pg, cr and o, large plaque variants in ib-rs-2 cells, when dd or ds were added to the agar overlay, the plaques were inhibited. however, the strains asq-pp and ci, that are small plaque variants in ib-rs-2 cells, when to the agar overlay was added dd the plaques were greatly enhanced while when was added ds the plaques were inhibite ...1978224842
[swine cell sublines with different ploidies. iii. susceptibility to foot-and-mouth disease virus].ib-rs-10-ii subline with tetraploid level cells was more susceptible to the infection by the foot-and-mouth disease virus (fmdv) asq-pg strain than ib-rs-10-i subline with diploid level cells, when number and size of plaques and cytopathogenic effect of the virus were used as criteria. besides, the virus yield in one-cycle of infection was almost the double in ib-rs-10-ii than ib-rs-10-i cell subline and the near-tetraploid cells were more susceptible to be infected by the virus than the near-di ...1978224843
[influence of a hypertonic medium on cell susceptibility to foot-and-mouth disease virus].the influence of hypertonic medium on the relationship between two cell clones of ib-rs-2 swine line and the foot-and-mouth disease virus was studied. although the number of infected cells was increased by the cell treatment with the hypertonic medium, before or during the time of virus adsorption and penetration onto the cells, showed by the plaque number, the viral replication was partially inhibited as showed by the plaque size as by the viral yield in one-cycle of infection. on the other han ...1978224844
foot and mouth disease virus. i. stability of its ribonucleic acid. 1978202081
persistence of foot-and-mouth disease virus in butter and butter oil. 197827543
pre-lytic release of foot-and-mouth disease virus in cytoplasmic blebs.the pre-lytic release mechanism of foot-and-mouth disease virus was investigated by immunofluorescence, acridine orange staining, and electron microscopy in infected bovine and porcine kidney coverslip cultures. cells with cytoplasmic fluorescence and which were positive for single stranded rna with acridine orange staining were observed at 2 h after infection. scanning electron microscopy showed cytoplasmic blebs in all cultures examined 2 h after infection. rounded cells with virus inclusions ...197881266
effect of trypsin treatment on the antigenic characteristics of plaque variants of type-o 1 and type asia-1 foot-and-mouth disease viruses.antigenic differences were demonstrated between the large and small plaque variants of both types o1 and asia-1 foot-and-mouth disease viruses. treatment of the large and small plaque variants of the viruses with trypsin essentially abolished the observed antigenic differences. thus, these plaque variants have antigenically different trypsin-sensitive determinants that may influence their immunogenicity and infection capabilities.197882610
effect of trypsin and chymotrypsin on the polypeptides of large and small plaque variants of foot-and-mouth disease virus: relationship to specific antigenicity and infectivity.large and small plaque variants of a12 foot-and-mouth disease virus were shown to have specific antigenic determinants. large plaque virus antigenic specificity was destroyed by trypsin treatment, but the small plaque antigen was resistant despite cleavage of the trypsin-sensitive polypeptide. the cleavage of polypeptide vp3 by trypsin resulted in the formation of a new antigen not present on untreated virus. the effects of chymotrypsin and trypsin on the polypeptides of the plaque variants have ...197884854
[production of purified foot-and-mouth disease virus antigens and the specific sera against them].it was demonstrated that the use of laboratory techniques could be contributive to the production of purified antigens of the f.m.d. virus, such a-140 s, 12 s, and via. the isolated purified antigens were used to immunize guinea pigs, obtaining specific antisera against them. it was found that the latter contained specific complement-fixing and precipitating antibodies, while the 140 s serum also had neutralizing antibodies. the produced 140 s serum contained certain amounts of 12 s antibodies, ...197885363
[effect of the contrast conditions using solutions of phosphotungstic acid on the electron microscopic image of the foot-and-mouth disease virus].a method of negative staining of foot-and-mouth disease virus preparations permits to obtain separately positive (2% phosphotungstic acid solution, ph 3.0) and negative (2% pta solution, ph 6.8 +/- 8.0) stainings. when a 3--4% pta solution, ph 6.8 +/- 8.0 is used, simultaneous positive and negative staining of each virion is possible which characterizes the functional heterogeneity of the virion protein membrane in interaction with pta anions.197992099
resolution of block neutralization test curves into components of the foot-and-mouth disease virus system.classic neutralization studies by fazekas de st. groth and webster (8) on mixtures of influenza viruses and mixtures of rabbit antisera are reinterpreted in terms of a percentage contaminant in the stock used for the dilution series. a very small amount of a different virus changes the shape of quantal assay curves considerably, but even a large amount of a different antiserum has negligible effect on the shape and merely shifts the curve along the serum dilution axis. these conclusions are the ...197992300
antibody response against foot and mouth disease virus (fmdv). part ii: responses measured in fractionated sera of infected steers with complete virus, trypsin treated virus, 12 s virus subunits, via and heterologous virus. 197993833
comparative biochemical and serological analysis of five isolates of a single serotype of foot-and-mouth disease virus.a comparison has been made of some of the biochemical and serological characteristics of five isolates of foot-and-mouth disease virus (fmdv), serotype a. three of the viruses have been assigned to the same subtype, a22; the other two belong to different subtypes, a5 and a24. rna competition hybridization and two-dimensional electrophoresis of the oligonucleotides produced by ribonuclease t1 showed that the three a22 viruses formed a group which could be distinguished from the a5 and a24 viruses ...197994348
comparison of the antibodies elicited by the individual structural polypeptides of foot-and mouth disease and polio viruses.antibody produced against preparations of vp1, one of the four structural polypeptides of foot-and-mouth disease virus, neutralized the virus and reacted with both full and empty particles in radioimmunoassays (ria). antiserum against vp2 reacted with artificial empty particles of the virus but not with full particles. in contrast, none of the individual polypeptides of poliovirus produced antisera which neutralized the virus nor reacted with it in ria. however, antisera produced with vp1 and vp ...197994352
[effect of the ph of the medium on the morphology of bp cell cultures and their sensitivity to the foot-and-mouth disease virus]. 197934920
structure of foot-and-mouth disease virus capsid. 197938568
morphogenesis of foot-and-mouth disease virus. i. role of procapsids as virion precursors.the role of procapsids during foot-and-mouth disease virus multiplication was studied on infected bhk-21 cells. purified virus and procapsids were obtained by treating the infected cytoplasmic extracts with rnase and edta. the synthesis of virus, procapsids, and total particles was determined in pulse-chase experiments. a precursor-product relationship between procapsids and virions was obtained. the results show that the rate of synthesis of total particles (virus + procapsids) was linear from ...1979225534
antibody response against foot and mouth disease virus (fmdv). part i: responses measured in sera of vaccinated steers with complete virus, trypsin treated virus, 12 s virus subunits and heterologous virus. 1979225907
[interaction between foot-and-mouth disease virus and the cells of different chronically infected animals]. 1979228472
isolation of foot-and-mouth disease virus messenger rna from membrane-bound polyribosomes and characterization of its 5' and 3' termini. 1979228483
the relation of poly(a) length to specific infectivity of viral rna: a comparison of different types of foot-and-mouth disease virus. 1979228485
a blastogenic test for foot-and-mouth disease.a blastogenic test to detect peripheral blood leukocytes specifically sensitized to foot-and-mouth disease virus antigen is described. the test is carried out in microtitre plates and optimum conditions were found by titration. these employed 7.5 x 10(5) cells/well and 20 complement fixing units of antigen. peak [3h]thymidine incorporation was found to take place at 2-3 days.1979229161
application of the enzyme linked immunosorbent assay to the detection and identification of foot-and-mouth disease viruses.an indirect enzyme linked immunosorbent assay (elisa) was applied to the detection and identification of foot-and-mouth disease (fmd) virus types. the test proved successful for the specific detection of virus from infected tissue culture, and from epithelial tissues from bovines suspected of having fmd. the elisa compared favourably with the complement fixation (cf) test, being more sensitive and unaffected by anticomplementary factors.1979229162
factorial experimental design applied to the immunological study of two foot-and-mouth disease virus subtypes. 2. theoretical study of experimental models.a certain number of theoretical models of immunological relations that 2 foot-and-mouth disease viruses can support, were constructed so as to discuss in each case, the results of the factorial analysis of the data. this method provided a specific answer to each of the questions that were asked in the presence of a test of this kind. the results obtained with several immunological cross-tests comparable to that of the a greece 69-a allier viruses, illustrated most of the theoretical models.1979231920
factorial experimental design applied to the immunological study of two foot-and-mouth disease virus subtypes. 1. a greece 1969 -- a allier example.a double immunological cross-test, carried out with the index k method, is subjected to a statistical analysis by a factorial experiment. the a greece and a allier viruses, which have been taken as an example of the calculations procedure, seem to be in 2 immunologically different subtypes.1979231923
purification and identification of the rna-dependent rna polymerase of foot-and-mouth disease virus.the rna-dependent rna polymerase induced in bhk 21 cells by infection with foot-and-mouth disease virus has been isolated from the replication complex. it contains a major, virus-coded protein with mol. wt. 56 000 which appears from serological studies and tryptic peptide mapping to be the same as the virus infection associated (via) antigen and the protein p56 found in cells infected with the virus. other virus coded proteins and a host cell protein were present in the partially purified replic ...1979232134
stability and immunogenicity of empty particles of foot-and-mouth disease virus.three strains of foot-and-mouth disease virus were shown to contain significant amounts of naturally occurring 75s, empty particles as well as the infectious, 140s full particles. one of these strains--a pando (1970)--was studied in detail. the empty particles from this virus strain were shown to have an observed sedimentation coefficient of 67s in 0.04 m phosphate buffer; they were labile in sds, non-infectious and probably rna-free and, on heating, they broke down to 12s subunits as did the 14 ...1979218538
relationship between virus neutralization and serum protection bioassays for igg and igm antibodies to foot-and-mouth disease virus.the time interval between administering the serum and the virus was found to influence the results of the in vivo mouse protection test for foot-and-mouth disease antibodies. in particular, for both igg and igm antibodies to strain a12 virus, the mouse protection index increased from zero to a maximum at about 6 h and remained high for at least five days. variations in the antiserum concentration, on a log scale, had a proportional effect on the mouse protection index, if between 1 and 3. the co ...1979219135
detection and quantification of foot and mouth disease virus by enzyme labelled immunosorbent assay techniques.enzyme labelled immunosorbent assays (elisa) have been developed to detect and quantify foot and mouth disease (fmd) virus using flexible plastic microtitre plates. the methods were successful for the specific detection of fmd virus and were 50 to 100 times more sensitive than the complement fixation test. the application of the elisa techniques to fmd virus typing and subtyping, and to the assay of antigen concentration during manufacture of vaccines is discussed.1979219137
[foot-and-mouth disease in buffaloes (bubalus bubalis, linnaeus, 1758): search of antiantigen antibodies and isolation of the virus].the immune response to virus-infection-associated (via) antigen was studied in 379 indian buffalos (bubalus bubalis). these animals were vaccinated three times a year with commercial acetylethyleneimine (aei)--inactivated foot-and-mouth disease vaccines under field conditions. two months after the last vaccination, antibody against virus-infection-associated (via) antigen was found in 23 per cent. foot-and-mouth disease virus -- (fmdv) type c "waldmann" was isolated from oesophageal/pharyngeal f ...1979233417
sequence and location of the poly c tract in aphtho- and cardiovirus rna.the poly c tract in the rna of the aphtho- and cardio viruses has been examined in several isolates of foot-and-mouth disease virus (fmdv) and encephalomyocarditis (emc) virus. the length of the tract is variable, containing 100 to 170 bases in the fmdv isolates and 80 to 250 bases in the emc virus isolates. each poly c tract contains c. 10% a and u residues, located at the 5' end, i.e. most of the tract is a continuous run of c residues. the position of the tract on the genome was the same in e ...1979223128
the specific detection of foot-and-mouth disease virus whole particle antigen (140s) by enzyme labelled immunosorbent assay.a solid-phase micro-enzyme-labelled immunosorbent assay (elisa) using guinea pig antiserum against purified (140s) inactivated foot-and-mouth disease (fmd) virus has been used in a sandwich technique to specifically measure 140s virus in the presence of 12s material.1979222837
immune response to virus-infection-associated (via) antigen in cattle repeatedly vaccinated with foot-and-mouth disease virus inactivated by formalin or acetylethyleneimine.the results of experiments to investigate antibody to 'virus infection associated' (via) antigen in cattle repeatedly vaccinated with formalin- or acetylethyleneimine- (aei) inactivated foot-and-mouth disease (fmd) vaccines under laboratory conditions are reported. results are also presented from some vaccinated animals subsequently exposed to fmd infection. antibody against via was not detected before and after the first vaccination with formalin or aei-inactivated vaccine but did develop in al ...1979216744
[treatment of swine cell line with antibiotics: effect on growth kinetics and susceptibility to foot-and-mouth disease virus and to mycoplasma-like organisms].cell cultures treated with tylosin tartrate and kanamycin sulphate antibiotics were studied in relation to the cell growth rate, the susceptibility to the foot-and-mouth disease virus and to the microorganism eradication. these treatments did not affect the cell growth rate and the cell behavior to the viral infection. on the other hand, the decontamination of the intracytoplasmatic formas of mycoplasma-like organism was not observed.1979233199
[isolation of bovine cell lines and susceptibility to foot-and-mouth disease virus].morphology and chromosomes of cell sublines derived from two new bovine kidney lines are reported. cell susceptibility to the foot-and-mouth disease virus is discussed. one of the sublines showed epithelial-like cells, while the remainder, elonged fibroblastic-like cells. most of them had a diploid number of chromosomes. from these sublines only one was sensible to the foot-and-mouth disease virus.1979233200
some aspects of fmdv-production in growing cells and a closed system for concentration of fmdv by polyethylene glycol.different commercially available peptone preparations, all derived by enzymatic digestion of meat, were tested for their ability to replace the individual amino acids and polyethylene glycol (peg)-treated serum in bhk suspended cell culture growth medium. cell growth was not impaired if the individual amino acids were replaced by 3 g/l of peptone in combination with 3 g/l lah and 5% peg-treated bovine serum. the concentration of the latter could be reduced to 1% by gradually lowering the concent ...1979223924
[formation of immunity in sheep inoculated with varying doses of the foot-and-mouth disease virus 0194]. 1979217141
the use of frozen bhk21 c13 cells to control the biological parameters for cell and foot-and-mouth disease virus growth.in order to control the four primary variables (cells, serum, medium and physical conditions) in a cell or virus growth system it is important to have a reliable and constant positive control with which to compare any variable of the system components. the use of aliquots of a frozen cell population (stored at -136 degrees c) for this purpose is the subject of this paper. using such cells, tests have been established for the control of sera, media, cell susceptibility and the quality of serum tr ...1979223922
cell culture on beads used for the industrial production of foot-and-mouth disease virus.the microcarrier culture technique has been applied to a pig kidney cell line. microcarriers consisted of deae sephadex a 50 beads washed and containing carboxymethyl cellulose. sifted beads gave better results than unclassified material. cells for inoculum were prepared in roux flasks. the two types of fermentors which were used (operating capacity 100 l and 150 l) gave similar results. the growth of the cells can easily be followed by microscopic observation and cell count. the yields of cells ...1979223917
development of a methodology for the production of foot- and- mouth disease virus from bhk21 c13 monolayer cells grown in a 100 l (20 m2) glass sphere propagator. 1979223915
serological comparison of a type sat 2 foot-and-mouth disease virus isolate from sudan with other type sat 2 strains. 1979232850
[subtypes of foot-and-mouth disease virus type a. genetic markers of clones obtained from 4 strains isolated in argentina between 1961 and 1970].the results obtained studying the genetic markers g, t and rtc of different clones of subtypes of foot-and-mouth disease virus type a are presented in this paper. the subtypes were isolated during outbreaks of foot and mouth disease in argentine. no significative differences among the subtypes were observed with the t marker. for the other markers, the results seem to indicate a gradual change related with the serological variation. because of their sensibility to guanidine hidrochloride, it is ...1979231800
[protective effect in the serum of rabbits inoculated with bhk-21 cells infected with foot-and-mouth disease virus].the present investigation was developed to determine the presence of protecting effects in the serum of rabbits inoculated with bhk 21 cells infected with foot-and-mouth disease virus, subtype c2. the rabbits received 252 mg. of antigens harvested 60, 65, 75, 90, 120 and 210 minutes post infection. these antigens were inactivated with two procedure: formaldehyde 0.015% and beta-propiolactone 0.2% and were inyected with incomplete freund's adjuvant; the last inoculations were given with live anti ...1979231797
the nucleotide sequence at the 5' end of foot and mouth disease virus rna.foot and mouth disease virus rna has been treated with rnase h in the presence of oligo (dg) specifically to digest the poly(c) tract which lies near the 5' end of the molecule (10). the short (s) fragment containing the 5' end of the rna was separated from the remainder of the rna (l fragment) by gel electrophoresis. rna ligase mediated labelling of the 3' end of s fragment showed that the rnase h digestion gave rise to molecules that differed only in the number of cytidylic acid residues remai ...1979231762
foot-and-mouth disease virus immunogenic capsid protein vpt: n-terminal sequences and immunogenic peptides obtained by cnbr and tryptic cleavages.the immunogenic capsid protein (vpt), circa 30 kiladaltons (kd), of foot-and-mouth disease virus was examined for (i) its ability to induce neutralizing antibody in guinea pigs after chemical modifications and cnbr or tryptic cleavages and (ii) n-terminal amino sequence homology across three virus types. the immunogenicity of vpt was inactivated by glutaraldehyde treatment, carboxymethylation and maleylation or citraconylation. however, de-citraconylation restored part of the lost activity. clea ...1979231585
the challenge of vaccinated pigs with foot-and-mouth disease virus. 1979231356
a new method for the isolation of undegraded fmdv-specific rna from infected bhk cells.fractionation of foot-and-mouth disease virus infected cells by currently described procedures, leads to the appearance of variable amounts of heterogeneous single-stranded rna fragments. a new method based upon the fractionation of cultured cells at extremely low temperatures has been developed to minimize the degradation of the viral rnas by cellular nucleases. it was shown that the viral rnas obtained by this procedure were almost non-degraded, and similar to those found in other picornavirus ...1979229806
inhibition of foot and mouth disease virus and procapsid synthesis by zinc ions. brief report.zinc ions inhibit virus production and viral rna synthesis in fmdv infected-bhk 21 cells. the degree of inhibition depends upon the zinc concentration and the time of addition of the drug. a differential inhibition on virus and procapsids synthesis was observed.1979229792
viral interference phenomena induced by foot-and-mouth disease temperature-sensitive mutants in bovine kidney cells.cultures of bovine kidney (bk) cells infected with temperature-sensitive (ts) mutants of foot-and-mouth disease virus (fmdv) were incubated at 38.5 degrees c, a temperature nonpermissive for mutant virus growth and rna synthesis. the cells were subsequently resistant to viral growth and rna synthesis when superinfected with wild-type fmdv and with heterologous fowl plague virus. the extent of interference was proportional to the multiplicity of infection of the ts mutant. it increased with time ...1979229787
isolation and characterization of trypsin-resistant o1 variants of foot-and-mouth disease virus.strains of foot-and-mouth disease virus of types o1 and a10 were isolated which showed no significant loss of infectivity upon trypsinization. these 'trypsin-resistant' (tr) viruses were obtained by serial passage in bhk cells of virus that was trypsin-treated before inoculation of the cells. three o1 isolates were cloned and studied further. cell attachment of those tr o1 variants (otr1) was not reduced by trypsinization, unlike that of parent virus. the polypeptide compositions of tr viruses a ...1979225425
immunity to foot-and-mouth disease virus in guinea pigs: clinical and immune responses.clinical and immune responses were determined for guinea pigs infected with different doses of foot-and-mouth disease virus (fmdv) type a12, strain 119, administered by different routes. vesicles developed on the tongue or heel pad 1 day after these areas were intradermally inoculated with fmdv. however, vesicles did not develop on the feet and tongue until 3 to 4 days after the intradermal inoculation of fmdv in the flank skin or after intracardiac or subcutaneous inoculation. infected guinea p ...1979223986
colour determination of beef juices as an indicator of beef cooking temperatures.dominant wavelengths and other colour parameters of beef juices were investigated as predictors of maximum internal temperatures attained during beef cooking since beef imported by the usa from south american countries has to be cooked to a temperature compatible with the inactivation of the foot-and-mouth disease virus. although the correlation between these parameters was highly significant, the prediction error was high and similar in magnitude to that obtained with other methods. however, ac ...197922055351
[enzymatic synthesis and properties of dna, complementary to foot and mouth disease virus rna].the rnas of the aphthosa virus, serotypes a and o were isolated and characterized. the complementary dnas used in experiments on molecular hybridization with matrix rnas were synthesized on virion rnas by means of reverse transcriptase.19806165404
aspects of heat inactivation of foot-and-mouth disease virus in milk from intramammarily infected susceptible cows.in skim milk obtained from susceptible cows after intramammary and intravenous inoculation (primary infected milk), foot-and-mouth disease (fmd) virus type o1 was slower inactivated by heat treatment than virus that had been added to pre-exposure skim milk. residual virus infectivity in heated primary infected milk was more efficiently detected in bovine thyroid cell cultures than in secondary pig kidney (pk2) cell cultures. untreated primary infected milk was found to inhibit both fmd-virus and ...19806244342
foot-and-mouth disease virus production in glass sphere based monolayer systems of 0.1 to 100 l medium volume.the cell and virus productivity of a 3 mm glass sphere based unit process monolayer system was determined at scales of 0.1, 1, 10 and 100 litres medium capacity. enhanced yields were obtained up to the 10l size when compared with control roux bottle cultures. modifications of the operating conditions of the 100l system should bring this into line with the smaller-scale units.19806244996
the potential of recombination for the production of foot-and-mouth disease virus vaccine strains.biological proof of recombination in foot-and-mouth disease virus has been provided by studies on a large suite of conditional lethal mutants and a recombination map of approximately 70 mutations has been produced. however, recombination is a highly variable phenomenon and this has cast doubt on its validity and certainly on its applicability to such practical purposes as the production of good vaccine strains. evidence is presented to demonstrate (1) that the genetic map has a good correlation ...19806244999
foot and mouth disease virus production on microcarrier-grown cells.the industrial usefulness of the production of foot and mouth disease virus with microcarrier grown cells has been tested at a large scale. the vaccines, intended for pigs, prepared with such virus give a good level of immunity against virulent challenges. they are stable and free from side effects.19806245001
early interactions of foot-and-mouth disease virus with cultured cells. 19806249029
detection of antibodies against foot-and-mouth disease virus using purified staphylococcus a protein conjugated with alkaline phosphatase.purified protein a (pa) from staphylococcus aureus was conjugated with the enzyme alkaline phosphatase. this reagent reacted well with pig, rabbit and guinea pig igg and less well with mouse and bovine igg. radioactive 125i-labelled pa showed a similar affinity for the iggs examined. antibodies against foot-and-mouth disease virus contained in guinea pig, rabbit and pig serum were detected, using the enzyme-conjugated pa in indirect tests, which were of similar sensitivity to those using enzyme- ...19806249867
some virus diseases of domestic animals in the sultanate of oman.little is known of the occurrence of animal virus diseases in the sultanate of oman. this paper reports the results of a countrywide survey carried out in 1978 to establish the prevalence of some important viral pathogens of domestic animals with the dual purpose of providing baselines for future investigations and guidelines for those entrusted with disease control. foot-and-mouth disease virus type o, previously identified in oman in 1976, was isolated from clinically affected animals. in addi ...19806251586
biochemical aspects of variation in foot-and-mouth disease virus.the biochemical basis for variation in foot-and-mouth disease virus (fmdv) has been explored by analysis of the virus rna and the virus-induced and structural proteins of three isolates of the virus. two of the isolates were from serotype a and the third was from serotype o. hybridization studies of the rnas showed greater than 80% homology between the two type a viruses and about 65% homology between the two type a viruses and the virus of type o. the ribonuclease t1 maps of the three viruses g ...19806243341
temperature-sensitive mutants of foot-and-mouth disease virus with altered structural polypeptides. i. identification by electrofocusing.the structural polypeptides of foot-and-mouth disease virus were analyzed by electrofocusing in a polyacrylamide gel containing 9 m urea. three versions of the technique were used to accomodate the widely differing isoelectric points of the four polypeptides. vp2 was identified by comparing mature virus with procapsids. the selective actions of proteases on virions of two serotypes and on their 12s particles were examined. from this emerged a simple test for distinguishing the similarly sized po ...19806246262
temperature-sensitive mutants of foot-and-mouth disease virus with altered structural polypeptides. ii. comparison of recombination and biochemical maps.the structural polypeptides of foot-and-mouth disease virus were digested with staphylococcus aureus v8 protease in the presence of sodium dodecyl sulfate. the protease-resistant peptides derived from temperature-sensitive mutants were compared with those of the wild type by electrofocusing in a polyacrylamide gel. covariation between the charge shifts of different peptides indicated that they shared common sequences: only five independent peptides in all were derived from vp1, vp2, and vp3, acc ...19806246263
[the rotating aeration (system fuchs) for treatment of liquid animal and municipal wastes. 8. the effect of aerobic treatment of foot and mouth disease virus]. 19806248023
[laboratory trials of culturing bhk 21 c 13 cells in a roller using an enzymatic egg hydrolysate-based nutrient medium].experiments were carried out to find the optimal conditions for the replication of bhk 21 c 13 cells in one 1 roller glassware with the use of a nutrient medium containing products of the enzymatic breakdown of white of egg. studied was the sensitivity of these cells to the type c strain 'hungary' of the foot-and-mouth disease virus. two series of f. m. d. vaccines were produced, which proved to be sterile and innocuous for guinea pigs. immunogenicity trials with regard to these animals revealed ...19806266126
isolation of a foot-and-mouth disease polyuridylic acid polymerase and its inhibition by antibody.a template-dependent polyuridylic acid [poly(u)] polymerase has been isolated from bhk cells infected with foot-and-mouth disease virus (fmdv). enzyme activity in a 20,000 x g supernatant of a cytoplasmic extract was concentrated by precipitation with 30 to 50% saturated ammonium sulfate. the poly(u) polymerase was freed of membranes by sodium dodecyl sulfate and 1,1,2-trichlorotrifluoroethane extraction, and rna was removed by precipitation with 2 m licl. the solubilized poly(u) polymerase requ ...19806251248
morphogenesis of vesiculation in foot-and-mouth disease.the morphogenesis of vesiculation in cattle inoculated (aerosol expsoure) with foot-and-mouth disease virus was investigated by examining alternate, frozen sections of selected tissues stained by fluorescent antibody technique and with hematoxylin and eosin. viremia preceded the development of lesions, and virus appeared to be transported to the epithelium via papillae. lesions were initiated usually by the infection of single cells in the stratum spinosum adjacent to the papillae. three types o ...19806255841
serological and immunological relations between the 146s and 12s particles of foot-and-mouth disease virus.intact 146s particles of the seven serotypes of foot-and-mouth disease virus (fmdv) produce type-specific precipitating, complement-fixing and neutralizing antibodies in cattle and guinea-pigs. however, the 12s structural subunit, produced from the virus particle by mild acid treatment (ph 6) or by heating at 56 degrees c, although stimulating the production of precipitating and complement-fixing antibodies, produces only low levels of neutralizing antibody. nevertheless, 12s antibody in guinea- ...19806257825
characterization of a foot-and-mouth disease mutant temperature-sensitive for viral rna synthesis.a temperature-sensitive (ts) mutant of foot-and-mouth disease virus (fmdv) did not produce rna polymerase activity nor synthesize viral rna when incubated in cells solely at the nonpermissive temperature (38.5 degrees c). infected cells initially incubated at 38.5 degrees c and then shifted down to 33 degrees c synthesized increased amounts of viral rna at earlier times compared to infected cells kept at 33 degrees c throughout, indicating that rna polymerase precursors were synthesized at 38.5 ...19806243922
location of the initiation site for protein synthesis on foot-and-mouth disease virus rna by in vitro translation of defined fragments of the rna.an mrna-dependent reticulocyte lysate has been used to translate foot-and-mouth disease virus rna in vitro. polypeptides p16, p20a, and p88, which have been shown to be derived from the 5' end of the rna by pactamycin mapping experiments with infected cells, were preferentially synthesized in vitro. removal of vpg, the small protein covalently linked to the 5' end of the genome rna, had no effect on the translation of the rna. the two rna fragments (l and s) produced by specific digestion of the ...19806245254
variation in the susceptibility of bhk populations and cloned cell lines to three strains of foot-and-mouth disease virus.bhk monolayer and suspension cell populations maintained in different laboratories were found to vary in their susceptibility to infection with three strains of foot-and-mouth disease virus (fmdv). the susceptibility of parent cell populations was compared with that of individual clones of cells derived from them. the populations tested in this way consisted of a number of cell types, each expressing a different capacity to produce fmdv. the relative numbers of susceptible and insusceptible cell ...19806245630
structural proteins of hand, foot and mouth disease viruses.coxsackievirus a16 (ca16) and enterovirus 71 (e71), which cause hand, foot and mouth disease, were compared with respect to their polypeptide composition by page. only three proteins were resolved for ca16, whereas the four characteristic structural proteins of e71, (vp1, vp2, vp3 and vp4) were separated. the distribution of labeled proteins suggested that the molecular weights of vp2 and vp3 of ca16 were very similar. the smallest protein, vp4, of ca16 and e71 had the same molecular weight, but ...19806246027
a study of the level of nucleotide sequence conservation between the rnas of two types serotypes of foot-and-mouth disease virus.the level of nucleotide sequence conservation between the rnas of type a and type o foot-and-mouth disease virus (fmdv) has been compared by three methods. (i) rna hybridization of fragments containing either the poly(c) tract at the 5' end of the rna of the poly(a) tract at the 3' end of the rna indicates that there is a similar level of sequence conservation (65% homology) across the genome. rnase t1 fingerprinting of these fragments did not show the presence of any long regions of completely ...19806257826
a study of the cross-reacting antigens on the intact foot-and-mouth disease virus and its 12s subunits with antisera against the structural proteins.cross-reactions between two strains of foot-and-mouth disease virus (fmdv) belonging to different serotypes (a and o) were studied with intact virus and virus subunits and antisera produced against the isolated structural proteins. anti-vp1 type o serum showed cross-reactive neutralizing activity, in contrast to the sera raised against intact virus type o, whereas anti-vp1 type a serum only neutralized homologous virus. anti-vp2, vp3 and vp4 did not show neutralizing activity. in the enzyme-link ...19806257830
the application of a single radial haemolysis technique to foot-and-mouth disease virus-antibody study.experiments are described for the evaluation of the single radial haemolysis (srh) technique applied to fmd virus, using a method involving the coupling of either antigen or antibody to sheep erythrocytes. the antigen coupling method detected specific antibody but the technique was found to be impractical as it gave reproducible results only with purified virions. however, the antibody coupling technique gave clear zones of lysis using tissue culture harvest virus as well as purified virus, and ...19806246855
heterogeneity of the genome-linked protein of foot-and-mouth disease virus.the genome-linked protein of foot-and-mouth disease virus was examined by electrofocusing in polyacrylamide gels. two proteins of different charge and amino acid composition were found. the tryptic peptide maps of the proteins were dissimilar. the possible relationship between the two proteins is discussed.19806247501
nucleotide sequence heterogeneity of the rna from a natural population of foot-and-mouth-disease virus.the genomic rna from isolates of foot-and-mouth-disease virus (fmdv) of serological types o or c obtained during epizootic outbreaks have been analysed by two-dimensional gel electrophoresis of the t1 rnase-generated oligonucleotides (t1 fingerprinting). among virus isolates that are closely related serologically, 4-12 oligonucleotide changes were detected constitute the genome, the variations affect 0.7%-2.2% positions in fmdv rna. higher nucleotide-sequence divergence exists between the genomi ...19806260578
foot and mouth disease virus. properties of a clone selected by terminal dilution technique from the original population.using the terminal dilution technique, a cloned virus was selected in a tissue culture systems from a heterogenous population of the original virus. the different markers studied differentiated the cloned virus from the original virus on the basis of its following characters: 1. ability to grow more efficiently at 29 than at 37 degrees c. 2. unstability of its capsid as seen by: a. high degree of sensitivity to heating at 50 degrees c for 10 min of exposure to ph 6.4 for 10 min. b. more inactiva ...19806254429
comparison of the nucleotide sequence at the 5' end of rnas from nine aphthoviruses, including representatives of the seven serotypes.the sequence of about 70 nucleotides at the 5' end of the rnas of nine different aphthoviruses (foot-and-mouth disease viruses), including representatives of the seven serotypes of the virus, has been determined by partial enzyme digestion of (32)p-end-labeled s fragment-that part of the rna lying to the 5' side of the poly(c) tract and including the 5' end of the molecule. the s fragments were prepared from polyadenylated virus-specific rna extracted from infected cells by digestion with rnase ...19806257918
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