Publications

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[characteristics of local anti-aphthous immunity as demonstrated by the titer of foot-and mouth disease virus in vaccinated cattle]. 195813547474
adaptation of the type c cattle virus of foot-and mouth disease to the brain of the white mouse. 195813594720
[foot and mouth disease virus in tissue culture in vitro. vi. preparation and titration of anti-foot and mouth disease serum obtained from cattle]. 195813624145
chemical and electrophoretic studies of the serums of cattle infected naturally with asia-1 type foot-and-mouth disease virus. 196113734388
growth of foot-and-mouth disease virus in dispersed tissue cells: i. methods of production.methods are described for rapid and economical production of large quantities of foot-and-mouth disease virus in stationary cultures of trypsin-dispersed bovine kidney cells in a simple medium. yields of between 10(7) and 10(8) plaque-forming units per milliliter were obtained from serum-free cultures containing approximately a million and a half viable trypsin-dispersed cells per milliliter. some of the advantages and disadvantages of these methods of virus production are discussed.196217649388
further studies of the early antibody in the sea of cattle and guinea pigs infected with foot-and-mouth disease virus. 196414218596
observations on the duration of immunity in cattle after experimental infection with foot-and-mouth disease virus. 196414234053
secretion of foot-and-mouth disease virus and antibody in the saliva of infected and immunized cattle. 196514317611
long-term observations on the antibody responses of cattle vaccinated with modified strains of foot-and-mouth disease virus. i. primary responses. 196514330933
isolation of variants during passage of a strain of foot-and-mouth disease virus in partly immunized cattle. 19654283920
influence of salts on foot-and-mouth disease virus.the effect of sodium and magnesium chloride in 1 and 2 m concentration at temperatures of 37 and 50 c on type c, strain 149, foot-and-mouth disease virus during storage for 6 days was studied. the exclusively passaged cattle strain and its tissue culture-adapted line were compared. preparations of the various chemicals and their concentrations were made directly in suspensions of the virus, which, together with untreated control virus suspensions, were stored at indicated temperatures and tested ...19664289623
[survival in cattle of the modified foot-and-mouth disease virus]. 19664296536
studies on the carrier state of cattle exposed to foot-and-mouth disease virus. 19665219023
further information on the persistence of infective foot-and-mouth disease virus in cattle exposed to virulent virus strains. 19665995671
detection of foot-and-mouth disease virus antibodies. i. "passive" hemagglutination test.a passive hemagglutination test has been developed to detect and measure foot-and-mouth disease virus (fmdv) antibody by using glutaraldehyde as a coupling reagent. an optimal concentration of 10 to 40 mug of virus per ml with 0.25% glutaraldehyde at 25 c for 1 hr was established for the sensitization of sheep erythrocytes. a reaction time of 18 hr at 4 c or 2 hr at 37 c induced good agglutination in the presence of specific antibody. sensitization was carried out in phosphate buffer, whereas ag ...19704318573
further information on the survival of modified foot-and-mouth disease virus in cattle. 19704337797
foot-and-mouth disease virus in cattle and pigs: use of polyethylene glycol or dextran for purifying 19s gamma-m immunoglobulin from sera. 19714325971
detection of foot-and-mouth disease virus antibodies. ii. use of fractionated bovine antisera for improving the specificity of a "passive" hemagglutination test.because 7s immunoglobulin (ig) g antibodies of low type specificity were present in mixtures with highly specific 19s igm antibodies, many bovine antisera to foot-and-mouth disease virus (fmdv) type a(12), strain 119 cross-reacted with type o of fmdv and to some degree with type c in the passive hemagglutination (ha) test. after 19s igm antibodies were separated by density gradient centrifugation or precipitated with 4% (w/v) polyethylene glycol, the antigen could be determined with "block" ha t ...19714329433
the survival of foot-and-mouth disease virus in african buffalo with non-transference of infection to domestic cattle. 19744364599
the effect of repeated vaccination in an enzootic foot-and-mouth disease area on the incidence of virus carrier cattle.a comparison was made of the incidence of foot-and-mouth disease virus ;carrier' cattle in an unvaccinated enzootic area and an area where routine 6-monthly vaccination with an inactivated vaccine had been carried out for 3-4 years. the incidence of carriers in the vaccinated area was 0.49% as compared to 3.34% in the non-vaccinated area. the results indicate that, provided the immune status of the vaccinated herd is maintained at a level sufficient to prevent outbreaks of clinical disease and t ...19744370898
production, isolation, and partial characterization of three foot-and-mouth disease virus temperature-sensitive mutants.three high temperature-sensitive (ts) mutants of foot-and-mouth disease virus were characterized by their relative abilities to grow at 33 or 38.5 c, to kill infant mice, to infect guinea pigs, and to produce foot-and-mouth disease in steers. mutants ts-24 and ts-42 did not grow at 38.5 c; both may have produced considerable quantities of noninfectious virus particles at 33 c. a third mutant, ts-22, appeared "leaky" because it multiplied to a limited extent during prolonged incubation at the non ...1975166915
cross-reactions of normal bovine serums to foot-and-mouth disease virus in plaque-reduction neutralization and radial immunodiffusion.serums from 150 cattle with no known exposure to foot-and-mouth disease (fmd) virus were tested by both the plaque-reduction neutralization (prn) technique and the radial immunodiffusion (rid) technique to evaluate the significance and the extent of cross-reactions in these tests. serums from 30 cattle from each of 5 locations were tested against representative viruses of each of the 7 types of fmd virus. high levels of cross-reactions with both the rid and prn techniques were found in serums of ...1975167625
growth of foot-and-mouth disease virus in the upper respiratory tract of non-immunized, vaccinated, and recovered cattle after intranasal inoculation.non-immunized, vaccinated, and recovered cattle were inoculated intranasally with various doses of foot-and-mouth disease virus. samples of oesophageal-pharyngeal (op) fluid were taken periodically for up to 7 days after inoculation and virus titres of these samples were plotted as pharyngeal virus growth curves. in non-immunized cattle, the length of the lag period and of the growth period were inversely proportional to the dose of virus given. maximum titres were observed when clinical signs w ...1976180177
[local interferon production in cattle after intranasal infection with avirulent ibr/ipv virus and its effect on a subsequent infection with foot-and-mouth disease virus]. 1976183421
survival of foot-and-mouth disease virus in cheese.persistence of foot-and-mouth disease virus during the manufacture of cheddar, mozzarella, camembert cheese prepared from milk of cows experimentally infected with the virus was studied. cheese samples were made on a laboratory scale with commercial lactic acid starter cultures and the microbial protease marzyme as a coagulant. milk was heated at different temperatures for different intervals before it was made into cheese. food-and-mouth disease virus survived the acidic conditions of cheddar a ...1976184130
effect of heat on foot-and-mouth disease virus (fmdv) in the components of milk from fmdv-infected cows.foot-and-mouth disease virus (fmdv) survived in skim milk, cream and the pelleted cellular debris components of milk obtained from fmdv-infected cows after pasteurization at 72 degrees c for 0-25 min. virus was recovered from whole milk of infected cows after that milk was heated at 72 degrees c. for 5 min. and from the skim milk component after it was heated at the same temperature for 2 min. evaporation of the whole milk samples after they were heated at 72 degrees c. for 3 min. did not inacti ...1976185284
pathogenesis of foot-and-mouth disease: clearance of the virus from the circulation of cattle and goats during experimental viraemia.viraemia is an important aspect of the pathogenesis of infectious diseases, but the mechanisms of entry and removal of virus from the vascular system particularly in natural hosts are poorly understood. the results of this study showed that the clearance of foot and mouth disease virus (fmdv) from the circulation of cattle and goats followed the general rules for the clearance of inert particulate materials and other viruses from the circulation. high doses of infused fmdv were cleared less effi ...1976185289
a foot-and-mouth disease vaccine for swine.an inactivated vaccine containing purified foot-and-mouth disease virus type o1, strain brugge, emulsified with incomplete freund's adjuvant was studied in swine. the antigen mass ranged from 0.02 to 416 mug in 0.25 ml of vaccine. at 90 days postinoculation (dpi) 33 to 100% of the swine which had been inoculated with 0.72% mug or larger amounts of antigen were protected against challenge. there was little protection at 182 dpi although the neutralizing titers obtained with 2.9, 34.6 and 416 mug ...1976187292
[use of indirect complement fixation test for studying foot and mouth disease virus].the indirect complement-fixation test was used in experiments for the subtype differentiation, and with the agar gel diffusion and the serum neutralization test was studied the immunity in cattle that had already recovered from foot-and-mouth disease or were immunized against the disease. it was found that the indirect complement-fixation test is instrumental in the demonstration of the antigenic differences between the foot-and-mouth viruses. comparative experiments have shown that the indirect ...1976189484
an evalutation of some methods of assay of foot-and-mouth disease antigen for vaccines.the relative merits of various in vitro assay systems for the measurement of the quality and quantity of foot-and-mouth disease virus vaccine antigen will be discussed. the assay systems include : viral infectivity, complement fixing activity, particle counts, radial diffusion titre and single radial haemolysis titre. the predictive value of the tests for the immunogenicity of the final vaccine product will be evaluated against the results of 50% protective dose titres determined in guinea pigs ...1976198302
antibody response of tropical range cattle to foot-and-mouth disease virus. i. comparison of three tests. 1976198305
cultivation of foot and mouth disease virus in bovine leukocyte cultures for use in the complement fixation test.bovine leukocyte cultures achieved good growth after 72 hours of cultivation. foot-and mouth disease (fmd) virus type 0 multiplied in such cultures to a titre of 10(6) tcid50/0.1 ml. the cell culture-grown virus was found to be suitable for the complement fixation test (cft) after purification and concentration with calcium phosphate.19769808
[several criteria of evaluation of foot-and-mouth disease virus reproduced in cell cultures in suspension].the study of the plaques produced by viruses asia and o1 reveals different properties which may depend on the virus or on the cell or its method of culture. antigenic differences and subsequent immunological differences correspond to differences in plaques. on the other hand, the cell line in suspension evolves both in its morphology and its receptivity during the passages. all these variations imply the observations of quantitative and qualitative criteria of evaluation in order to prepare vacc ...197671255
further observations of foot and mouth disease virus type s.a.t 1 infection of cattle in tanzania. 197616300346
cross reaction between bovine enterovirus and south african territories i5 foot-and-mouth disease virus.a bovine enterovirus (e76t) isolated from a 2-year-old bull produced serologic cross reactions to south african territories (sat) i5 foot-and-mouth disease virus when inoculated into guinea pigs and cattle. cross-reacting serum titers to sat i5 virus of 1:320 by the plaque-reduction neutralization test and 1:20 by the radial immunodiffusion test occurred in 2 steers after they were inoculated with the e76t virus. in 1 steer, maximal cross-reacting titers appeared related to a 2nd exposure to the ...1978204230
cross reactions of normal bovine sera with foot-and-mouth disease virus: incidence, duration, and effect of shipping stress.serum samples were obtained from 30 hereford steers in an area known to be free of foot-and-mouth disease (fmd) viruses as follows: before shipment and 4 times during a 70-day period after shipment; the sera were tested for the presence of cross-reacting antibody to various viruses. percentages of sera containing cross-reacting antibody to fmd virus detected by the plaque-reduction neutralization and the radial immunodiffusion techniques were higher for the fmd viruses asia and sat i5 than for t ...1978206170
in vitro comparison of foot-and-mouth disease virus subtype variants causing disease in vaccinated cattle.foot-and-mouth disease virus isolates of types o, a and sat 2, from diseased animals in herds routinely vaccinated twice a year were compared antigenically with the vaccine strains in the complement-fixation, neutralization and radial immunodiffusion tests. it was found that strains which had readily infected vaccinated cattle had r values against the vaccine strain in the complementfixation and radial immunodiffusion tests of 30 or less, while strains causing primary outbreaks with little sprea ...1978206626
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
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
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
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
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
detection and quantification of igm, iga, igg1 and igg2 antibodies against foot-and-mouth disease virus from bovine sera using an enzyme-linked immunosorbent assay.a simple solid-phase enzyme immunoassay is described for the detection of antibody classes showing activity against foot-and-mouth disease (fmd) virus in bovine sera. the assay achieves a preliminary separation of the specific class of antibody from other serum proteins through immuno-adsorption to class-specific immunoglobulin-coated wells of micro-titre plates. the specific antibody is reacted with fmd virus, which is then detected by an enzyme-labelled anti virus igg.19816257779
identification of a protein kinase activity in purified foot- and-mouth disease virus.purified preparations of foot-and-mouth disease virus types a, o, and c contain a protein kinase activity which can transfer the gamma phosphate of [32p]atp to virion structural proteins vp2 and vp3 and exogenous acceptor proteins. utilizing protamine sulfate as an acceptor, the kinase activity can be demonstrated in disrupted virus but not in intact virus. the enzyme is heat labile with optimal activity at ph 7 or greater. serine residues of protamine sulfate were identified as the amino acid p ...19816268834
vesicular exocytosis of foot- and -mouth disease virus from mammary gland secretory epithelium of infected cows.foot-and-mouth disease virus particles were observed by electron microscopy in the cytoplasma of alveolar secretory cells of the bovine mammary gland after contact exposure of uninfected cows to pits with foot-and-mouth disease. virus, contained in membrane-limited vesicles, was released from the basal and peranuclear portions of the cells into the intracellular and extracellular spaces by an exocytotic mechanism similar to that of the release of th milk-fat globule. virus was released into the ...19816271913
cloned viral protein vaccine for foot-and-mouth disease: responses in cattle and swine.a dna sequence coding for the immunogenic capsid protein vp3 of foot-and-mouth disease virus a12, prepared from the virion rna, was ligated to a plasmid designed to express a chimeric protein from the escherichia coli tryptophan promoter-operator system. when escherichia coli transformed with this plasmid was grown in tryptophan-depleted media, approximately 17 percent of the total cellular protein was found to be an insoluble and stable chimeric protein. the purified chimeric protein competed e ...19816272395
a micro-enzyme-lavelled immunosorbent assay (micorelisa) for the detection of foot-and-mouth disease virus antigen and antibody.the indirect technique of a micro-enzyme-labelled immunosorbent assay (microelisa) was standardized and found efficient in detecting the foot-and-mouth disease virus antigen in cell culture fluids, mice carcases and cattle tongue epithelium as well as the antibody titre of sera.19816112866
subtyping of foot-and-mouth disease virus by the micro-enzyme-labelled immunosorbent assay (microelisa).the micro-enzyme-labelled immunosorbent assay (microelisa) was used successfully for the subtyping of foot-and-mouth disease (fmd) virus strains recovered from field outbreaks. the rabbit anti-guinea pig globulin-peroxidase conjugate employed in the indirect microelisa has the advantage of being used with any of the seven types of fmd virus.19816112867
serological differentiation of foot-and-mouth disease virus on electron microscope grids coated with protein a and antibody.a serological technique using electron microscope grids coated with protein a and antiserum was able to detect foot-and- mouth disease virus particles in oesophageal-pharyngeal fluids from infected cattle without the need for prior concentration of the sample. the technique was adapted to differentiate serologically among foot-and-mouth disease virus types a, o and c with antigen-adsorbed sera. when grids were coated with heterotypic antigenadsorbed antisera, the homotypic antigen could be obser ...19816280815
sensitivity of seven different types of cell cultures to three serotypes of foot-and-mouth disease virus.the ability of bovine tongue origin foot-and-mouth disease virus serotypes a, o and c to replicate in seven different types of cell cultures was studied. primary and secondary calf thyroid cells were equivalent in susceptibility to bovine kidney cell cultures passaged up to five times. calf thyroid cells lost their susceptibility after two passages. cryopreserved bovine kidney cell cultures passaged three and four times were equivalent in susceptibility to sensitive calf thyroid and bovine kidne ...19826284329
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 ...19826285433
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 ...19826287701
concentration of foot-and-mouth disease virus in milk of cows infected under simulated field conditions. 19826292275
competition for cellular receptor sites among selected aphthoviruses.the competition between different types of aphthoviruses (foot-and-mouth disease virus [fmdv]) for receptor site utilization was determined. the southern african territories (sat) types of fmdv absorbed poorly to bhk-21 cells as measured by a radioactivity binding assay but grew to relatively high titers on these cells. on bk cells, however, all three sat types bound well and competed with each other for receptor sites. in addition, unlabeled fmdv types a12 and o1b were able to completely inhibi ...19826297430
stimulation by heterotypic antigens of foot-and-mouth disease virus antibodies in vaccinated cattle.immunisation of cattle with foot-and-mouth disease virus failed to raise a level of antibody that provides protection against heterotypic challenge. further the 12s substructure, produced from the 146s particle, was ineffective in providing protection against challenge by homotypic virus. these findings suggest considerable antigenic differences in the virus serotypes and between the virus and its substructure. inoculation of homologous 12s and heterologous 1246s and 12s antigens into vaccinated ...19826179141
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 ...19826278697
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 ...19836189669
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 ...19836297845
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 ...19836302144
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 ...19836306155
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 ...19836310850
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 ...19836312518
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 ...19836313290
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 ...19836315737
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 ...19836315813
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 ...19836318421
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 ...19836321000
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. ...19836322643
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 ...19836099640
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 ...19846323757
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 ...19846330120
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 ...19846088803
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 ...19846090465
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 ...19846093338
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 ...19846099140
indirect immunofluorescence and immunodiffusion tests in the detection of antibodies to foot-and-mouth disease virus.the antibody response detected by indirect immunofluorescence (iif) as well as that directed against 140 s and virus infection associated antigen (via), as detected by agar immunodiffusion, was studied in three mammal species susceptible to foot and mouth disease virus, after challenge with living virus, immunization and hyperimmunization with inactivated virus, and immunization followed by challenge. by spot indirect immunofluorescence, antibodies were detected only in animals undergoing an act ...19852983488
dose-response evaluation of a genetically engineered foot-and-mouth disease virus polypeptide immunogen in cattle.four groups of 9 cattle each were vaccinated with 10, 50, 250, or 1,250 micrograms of foot-and-mouth disease (fmd) virus a12 vp1 fusion protein that was produced in escherichia coli and emulsified in an oil adjuvant. the groups given the 10 and 50 micrograms of antigen were revaccinated at 15 weeks and were challenge exposed at 30 weeks; 5 of 9 and 7 of 9 cattle, respectively, were protected from fmd virus infection. the remaining 2 groups, vaccinated with 250 or 1,250 micrograms of antigen, wer ...19852986495
detection of foot-and-mouth disease virus antibody using counterimmunoelectrophoresis and serum neutralisation tests.a comparative investigation was made on the applicability, sensitivity and specificity of counterimmunoelectrophoresis (ciep) for the rapid detection of antibody to foot-and-mouth disease virus in cattle sera using as reference a standard serum neutralisation test. the ciep test was sensitive and exhibited a reasonable specificity.19852992139
buffalo in the northern natal game parks show no serological evidence of infection with foot-and-mouth disease virus.a total of 594 sera collected from buffalo (syncerus caffer) in the hluhluwe/umfolozi game reserve complex, ndumu game reserve and the eastern shores of lake st lucia were examined for antibody to sat 1, 2 and 3 types of foot-and-mouth disease (fmd) virus in neutralization tests. no neutralization of sat 2 or 3 viruses was exhibited by any of the sera tested at final dilutions greater than 10. a small proportion (2,9%) of sera neutralized sat 1 virus at dilutions up to 10, but these were conside ...19852995896
biochemical characterization of an aphthovirus type 0(1) strain campos attenuated for cattle by serial passages in chicken embryos.the biochemical properties of a virulent and an attenuated strain of foot-and-mouth disease virus (fmdv) type 0(1) campos (0(1)c) were compared in order to establish differences that could account for their altered biological functions. the avirulent strain (0(1)c-o/e) was derived from the virulent strain 0(1)c by serial passages in chicken embryos. analysis of the rnase t1-generated oligonucleotides of the viral rna through one- and two-dimensional (2d) gel electrophoresis (fingerprints) reveal ...19852998071
a study of antigenic variants of foot-and-mouth disease virus by polyacrylamide gel electrophoresis of their structural polypeptides.twenty-nine foot-and-mouth disease (fmd) type a virus strains, previously classified serologically as distinct subtypes were analysed by polyacrylamide gel electrophoresis (page) to determine the extent of variation in the pattern of the structural polypeptides and to evaluate the technique as an aid to existing subtyping techniques. the majority of the subtypes examined had distinct polypeptide patterns, however, some variation also occurred between strains within a subtype. the position of vp2 ...19852412337
variation in foot-and-mouth disease virus isolates in kenya: an examination of field isolates by t1 oligonucleotide fingerprinting.ribonuclease t1 oligonucleotide maps of strains of 4 of the endemic serotypes of foot-and-mouth disease virus isolated in kenya between 1964 and 1982 have been compared with data obtained in complement-fixation and neutralization tests. there was a continual change in the oligonucleotide maps obtained for all the serotypes examined. this genetic heterogeneity was generally associated with antigenic variation. viruses isolated during the 12-month course of an epidemic of the sat 1 serotype showed ...19852413611
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 ...19852415086
biochemical characterization of a foot-and-mouth disease virus strain attenuated for cattle. brief report.wild-type, virulent (a-24 cruzeiro subtype) foot-and-mouth disease virus (fmdv), a related attenuated strain and revertants of the attenuated strain were examined by titration on primary bovine kidney (pbk) and baby hamster kidney (bhk-21) cells, as well as, by infection of unweaned mice. wild type virus grew equally well in all three systems, whereas the attenuated strain had a titer 2-3 log lower in pbk cells than in the other 2 assays. within 9 successive passages in bhk-21 cells the attenuat ...19863006639
protection of cattle against foot-and-mouth disease by a synthetic peptide.a chemically synthesized peptide consisting essentially of two separate regions (residues 141 to 158 and 200 to 213) of a virus coat protein (vp1) from the o1 kaufbeuren strain of foot-and-mouth disease virus was prepared free of any carrier protein. it elicited high levels of neutralizing antibody and protected cattle against intradermolingual challenge by inoculation with infectious virus. comparative evaluation of this peptide with a single-site peptide (residues 141 to 158) in guinea pigs su ...19863008333
potential for the transmission of foot-and-mouth disease virus from african buffalo (syncerus caffer) to cattle.foot-and-mouth disease viruses of types sat 1 and sat 2 isolated from diseased cattle and carrier buffalo, either on the same farm or in the same ecological area within a short time of each other, were compared by t1 oligonucleotide mapping. no similarity was observed between the maps obtained, indicating that the different populations of virus were unique to each species and that no interspecies transmission had occurred.19863010415
[a hitherto unknown reaction pattern in vertebrate cells (riv). 2. the protective effect of riv particle preparations against foot-and-mouth disease in guinea pigs].further observations concerning the previously described riv-particles are reported. they were isolated from a diploid cell line of bovine origin, embryonal duck fibroblasts and bhk-21 cells. a protective effect against foot-and-mouth-disease virus in guinea pigs could be observed following inoculation with the riv-preparation of bovine origin. all 3 preparations isolated from the 3 cell lines showed immunologic cross reactions.19863020838
a new enzyme-linked immunosorbent assay (elisa) for the detection of antibodies against foot-and-mouth disease virus. i. development and method of elisa.a liquid-phase blocking sandwich elisa has been developed for the quantification of antibodies against foot-and-mouth disease virus which may replace the virus neutralisation (vn) test. this test employs the incubation of a constant amount of antigen with a range of test serum dilutions in the liquid-phase before being assayed using a trapping elisa. thus it does not rely on the availability or growth of tissue culture cells. the assay is rapid and relatively simple to perform, reagents are used ...19863021854
a new enzyme-linked immunosorbent assay (elisa) for the detection of antibodies against foot-and-mouth disease virus. ii. application.the liquid-phase blocking sandwich elisa has been evaluated for the serological study of antibodies against foot-and-mouth disease virus (fmdv). the titres recorded for sera from a population of more than 300 british uninfected, unvaccinated cattle which were examined against each of the seven immunologically distinct fmdv types were less than 1 in 40. a positive correlation between elisa and vn titres was recorded for sera either vaccinated or involved in outbreaks of fmdv. the overall regressi ...19863021855
antigenic comparison of foot-and-mouth disease virus serotypes with monoclonal antibodies.the capsid structures of the 7 serotypes of foot-and-mouth disease virus have been compared utilizing a series of neutralizing monoclonal antibodies which were previously shown to recognize at least 4 distinct epitopes on type a12 virus. a radioimmune binding assay using radioactively labeled antigens and the monoclonal antibodies revealed that certain conformation dependent epitopes are conserved among a subtypes, while some continuous epitopes are conserved among a subtypes as well as other fm ...19863026110
proceedings - embryo transfer in the canadian cattle industry status of disease transmission studies and thier relationship to the international movement of bovine embryos.the current, generally accepted approach to formulating health requirements for the international movement of embryos is to base them on the health status of the male and female donor animals. the alternative approach of basing them on the health status of the embryos themselves has been blocked by the lack of scientific information about the potential of the early embryo to transmit agents of infectious disease. consequently, most research into infectious disease transmission by embryos has had ...198617422615
embryo transfer as a means of controlling the transmission of viral infections. vii. the in vitro exposure of bovine and porcine embryos to foot-and-mouth disease virus.when 169 zona pellucida-intact bovine embryos were exposed to 10(6) pfu/ml of foot-and-mouth disease virus and then washed, no infectious virus was detected on any of the embryos. fmd viral infectivity was found, however, in association with 14 of 42 hatched (zona pellucida-free) bovine embryos and in a small number of zona pellucida-intact porcine embryos. the porcine embryos were assayed individually and in groups of 8 embryos. four of the 124 individual embryos and 2 of the 9 groups of embryo ...198616726224
peptide vaccine--a new approach to a safer foot-and-mouth disease virus vaccine.a synthetic peptide, of which the region of the major antigenic determinant of foot-and-mouth disease virus serotype o1k located on the coat protein vp1 consists, was coupled to different protein carriers. comparing the potency of the conjugates to elicit neutralising antibodies it has been shown that klh was the best carrier protein. using different amounts of peptide a (aa 144-aa 159) the dependence of neutralising antibody response on the amount of injected peptide has been demonstrated. pept ...19873032213
multiple variants in foot-and-mouse disease virus (fmdv) populations: the achilles heel for peptide and rec. dna vaccines?variants of type a10 fmdv were isolated by passage of virus in bhk-cells in the presence of a neutralizing anti-peptide serum or monoclonal antibodies. these variants which were no longer neutralized by the particular anti-peptide serum or monoclonal antibody were easily obtained from (crude) virus populations ("cattle" virus and bhk-adapted virus). the rapidity of isolation (in two or three passages) suggested that these variants are already present in normal virus populations. all (plaque puri ...19873034708
effect of lysosomotropic compounds on early events in foot-and-mouth disease virus replication.the effect of three lysosomotropic compounds, chloroquine, monensin and nh4cl, on the replication of foot-and-mouth disease virus (fmdv) type a12 was studied. viral replication was almost totally inhibited by 0.5 mm chloroquine, 50 microm monensin, or 25 mm nh4cl. monensin and nh4cl affected replication when added either before or within the first hour of infection. chloroquine, however, still inhibited viral replication when added up to 2.5 h after infection. assays of binding of radiolabeled v ...19873037820
enzyme-linked immunosorbent assay (elisa) for the detection of antibodies against foot-and-mouth disease virus. iii. evaluation of antibodies after infection and vaccination.investigations using a liquid-phase blocking sandwich enzyme-linked immunosorbent assay (elisa) for the measurement of antibodies against foot-and-mouth disease virus (fmdv) in sera from sheep and from cattle are reported, and results compared with those obtained by virus neutralization (vn) tests. serum antibody titres in sheep after primary vaccination and in cattle challenged with a natural aerosol after vaccination were similar by elisa and vn. however, the antibody levels detected in sera o ...19873428376
serologic survey of viral antibodies in the peruvian alpaca (lama pacos).sera from more than 100 alpacas (lama pacos) from the peruvian southern sierra were examined for antibodies to 8 viruses known to infect other domestic animals. on the basis of these serologic findings and previously published serologic or clinical data, it is now known that the alpaca can be infected with the following viruses: parainfluenza-3, bovine respiratory syncytial virus, bovine herpesvirus-1, bluetongue virus, border disease virus, influenza a virus, rotavirus, rabies virus, vesicular ...19873826854
infection of cattle by airborne foot-and-mouth disease virus: minimal doses with o1 and sat 2 strains.equipment has been constructed and methods developed for exposing individual cattle to two strains of foot-and-mouth disease (fmd) virus in aerosols to determine the minimal infective dose by the respiratory route. the aerosols used were produced either artificially by a spinning-top aerosol generator, in which case they were of homogeneous small particle size (less than 3 micron in diameter) or else they were derived naturally from infected pigs, in which case the particles were heterogeneous i ...19872832913
antigenic comparison of the polypeptides of foot-and-mouth disease virus serotypes and other picornaviruses.the cross-reactivity of proteins coded for by the seven serotypes of foot-and-mouth disease virus (fmdv) was assessed by reaction of infected cell lysates with polyclonal and monospecific antisera against the structural and nonstructural proteins of fmdv type a12 strain 119ab. it was shown that the homologous polypeptides from most serotypes are antigenically related. the least cross-reactivity occurred between vp1, vp3, and the protease (3c) of type a12 and south african territories types 1 and ...19872437694
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