| analysis of naturally occurring deletion variants of african swine fever virus: multigene family 110 is not essential for infectivity or virulence in pigs. | a comparison of uncloned african swine fever virus isolates with their cloned counterparts revealed the presence of genetic variants in three out of seven uncloned field virus populations tested. five different virus clones were isolated from the uncloned kir69 virus stock by limit dilution. structural analysis of the variants showed that they differed by single deletions of 10-16 kilobases in the region located between 6.8 and 27 kilobases from the left dna terminus. there was no homology betwe ... | 1990 | 2330671 |
| evaluation of sensitivity of different antigen and dna-hybridization methods in african swine fever virus detection. | elisa, immunodot and dna hybridization methods have been adapted to detect african swine fever virus (asfv), and their sensitivities were compared using virus obtained from cell cultures. about 2.3 x 10(2) 50% hemadsorbing doses (had50) of virus were detected with elisa sandwich using an anti-asfv igg biotinylated followed by avidin-peroxidase. the immunodot technique showed similar sensitivity, detecting about 4.6 x 10(2) had50 of virus. asfv-dna was detected using radioactive dna probes and mo ... | 1990 | 2347889 |
| pulmonary intravascular macrophages in lungs of pigs inoculated with african swine fever virus of differing virulence. | the role of pulmonary intravascular macrophages (pim) in a viral infection has been studied by structural and ultrastructural methods with two strains of the african swine fever (asf) virus: the virulent strain e70 and the attenuated strain e75. pulmonary intravascular macrophages were the cells of the mononuclear phagocyte system of the lung most involved in the replication of strain e70, showing a marked cytopathic effect and necrosis. concurrently, their size and number increased sharply. thi ... | 1990 | 2365848 |
| pestivirus glycoprotein which induces neutralizing antibodies forms part of a disulfide-linked heterodimer. | neutralizing monoclonal antibodies directed against hog cholera virus (hcv) precipitated two hcv-encoded glycoproteins, hcv gp55 and hcv gp33. immunoassay with bacterial fusion proteins and western immunoblotting with extracts from infected cells revealed that the antibodies recognized only hcv gp55. coprecipitation of hcv gp33 was shown to be due to intermolecular disulfide bridges. one of the antibodies also reacted with the major glycoprotein of another pestivirus, bovine viral diarrhea virus ... | 1990 | 2370675 |
| absence of ornithodoros moubata, the vector of african swine fever virus, from the main pig producing area of cameroon. | no evidence for the presence of soft ticks of the ornithodoros moubata complex was found during a survey of african swine fever carried out between 1985 and 1988 in the west province and southern parts of the north west and south west provinces of cameroon. the survey consisted of interviews of veterinary assistants and farmers, distribution of a questionnaire and tick searches both manually and with carbon dioxide traps. the absence of warthogs (phacochoerus aethiopicus) from these areas was al ... | 1990 | 2371751 |
| evidence for an acid phosphatase in african swine fever virus. | an acid phosphatase activity has been detected in purified preparations of african swine fever virus. purified viral cores obtained after nonidet-p40 and 2-mercaptoethanol treatment of the virus retained the activity as assayed with nitrophenyl phosphate as substrate at ph 5. enzyme cytochemistry by electron microscopy showed that the acid phosphatase activity is localized mainly inside the core of the virion. the molecular weight and the isoelectric point of the virus acid phosphatase activity ... | 1990 | 2386433 |
| sequence and evolutionary relationships of african swine fever virus thymidine kinase. | the thymidine kinase gene of african swine fever virus was mapped in a 1.4-kb ecori-psti fragment located in the left half of the eco ri k fragment of african swine fever virus dna by using degenerate oligonucleotide probes derived from regions of the thymidine kinase sequence conserved in several poxviruses, man, mouse, and chicken. the nucleotide sequence of this region revealed an open reading frame of 196 codons, whose translated amino acid sequence showed significant similarity to the thymi ... | 1990 | 2389555 |
| nucleotide sequence of hog cholera virus rna: properties of the polyprotein encoded by the open reading frame spanning the viral genomic rna. | hog cholera virus rna was cloned and sequenced. a single major open reading frame (orf), encoding an amino acid sequence of 3898 residues, was found in the second reading frame of the sequence of one of the cdna strands. we demonstrated that the orf spans the length of the viral sense rna, which implies that it is translated into a precursor polyprotein. several properties of this polyprotein, like hydrophobicity, position of putative protease cleavage sites, distribution of n-linked glycosylati ... | 1990 | 2402871 |
| monoclonal antibodies of african swine fever virus: antigenic differences among field virus isolates and viruses passaged in cell culture. | an analysis of the binding properties of a collection of monoclonal antibodies to african swine fever virus particles showed that virus field isolates passaged in porcine macrophages changed antigenically more than a strain of a cell-adapted virus passaged in vero cells. from seven clones isolated from the spleen of a field-infected pig, we found four clones that had the same antigenic properties, one clone that had large changes in proteins p150 and p27 and small changes in proteins p37 and p14 ... | 1986 | 2422393 |
| production of monoclonal antibodies against swine fever virus and their use in laboratory diagnosis. | thirteen hybridoma cell lines which secrete monoclonal antibodies (mcas) against swine fever virus (sfv) strain brescia were produced. the hybrid cells resulted from fusion of p3x63-ag8.653 myeloma cells with splenocytes of balb/c mice which had been immunized with purified sfv. screening of supernatant fluids was performed by an indirect enzyme-linked immunosorbent assay (elisa) and an immunoperoxidase monolayer assay (ipma). the ipma, and an immunoperoxidase test (ipt) performed on cryostat se ... | 1986 | 2428160 |
| [studies of the antigen structure of pestiviruses using monoclonal antibodies]. | | 1987 | 2448112 |
| epitopic diversity of african swine fever virus. | african swine fever (asf) is caused by an icosahedral cytoplasmic, double stranded dna virus. in the acute form of the disease, pigs die from disseminated intravascular coagulation (dic) with extensive damage of the free and fixed macrophage systems and the reticular epithelial cells of the thymus; mortality is virtually 100%. in recent years, subacute and chronic forms of asf have become more prevalent in the field, especially in outbreaks occurring outside the continent of africa, and virus is ... | 1988 | 2451366 |
| an enzyme immunoassay employing monoclonal antibodies and detecting specifically antibodies to classical swine fever virus. | an enzyme immunoassay (complex-trapping-blocking elisa, ctb elisa) for the detection of antibodies against classical swine fever virus (sfv) has been developed. the ctb elisa employs two monoclonal antibodies directed against different antigenic sites of sfv. a set of 2545 pig sera was tested in the ctb elisa and in the neutralizing peroxidase-linked assay (npla) for neutralizing antibody to sfv. the ctb elisa and the npla confirmed each other in 97% of the sera. the ctb elisa detects low-level ... | 1988 | 2459837 |
| variable and constant regions in african swine fever virus dna. | an analysis of the sali restriction pattern of african swine fever virus dna showed that the sali recognition sites did not change after more than 100 virus passages in porcine macrophages. the virus strain ba71v, obtained from the virus isolate ba71 by adaptation to grow in vero cells, differed from the nonadapted virus in two deletions with a length of 2.5 and 7 kb located close to the dna ends. a restriction analysis of several virus clones obtained from a naturally infected pig revealed leng ... | 1989 | 2464873 |
| high titre hog cholera virus production on cytodex 3 microcarrier cultures. | in an attempt to produce hog cholera virus (hcv) preparations of high titre, optimal growth and trypsinization conditions of pk-15 microcarrier cell cultures were defined. infecting a pk-15 cytodex 3 microcarrier culture with hcv increased the yield of virus more than 10 times compared with conventional monolayer culture in roux flasks. | 1989 | 2470336 |
| topographical and functional mapping of epitopes on hog cholera virus with monoclonal antibodies. | competitive binding studies and antigen capture assays were done with monoclonal antibodies (mabs) raised against hog cholera virus (hcv) to map the corresponding epitopes. a model was constructed in which the 13 epitopes were situated in four distinct antigenic domains: a, b, c and d. domain a was subdivided into a1, a2 and a3. the functional relevance of this model was assessed by the characterization of pestivirus strains, by neutralization studies with the mabs, and by isolation of variants ... | 1989 | 2479712 |
| a survey of wild swine in the united states for evidence of hog cholera. | the results of surveillance for hog cholera (hc) in wild swine (sus scrofa) collected from throughout the united states from 1979 to 1987 are presented. sera collected from 1,218 wild swine and tissues from 637 were evaluated for hc antibodies and virus, respectively. included within this surveillance were samples from santa cruz and santa rosa islands, california, where hc virus had been deliberately introduced into wild swine during the 1950's in attempts to eradicate these animals. all evalua ... | 1989 | 2536850 |
| differentiation of hog cholera and bovine virus diarrhoea viruses in pigs using monoclonal antibodies. | monoclonal antibodies against hog cholera and bovine viral diarrhoea viruses were assayed on organ tissue sections of experimentally infected animals. the animals had been infected simultaneously with both viruses. the antibodies were tested using an indirect immunofluorescence test and an indirect enzyme immunoassay with a biotin/streptavidin/peroxidase detection system. a polyclonal hyperimmune serum was used as a control in direct immunofluorescence tests. both techniques based on monoclonal ... | 1989 | 2538980 |
| application of peroxidase labelled antibody assays for detection of porcine igg antibodies to hog cholera and bovine viral diarrhea viruses. | rapid, sensitive peroxidase labelled antibody (pla) assays using microtiter systems, were developed for detection of hog cholera virus (hcv) and cross-reacting bovine viral diarrhea virus (bvdv) antibodies in pig sera. hcv-infected pig kidney cell line (pk 15) prepared in microtiter plates were fixed and used in pla assays. after inoculation with test serum, bound antibodies (hcv/bvdv) were reacted with either horseradish peroxidase (hrp) conjugated anti-porcine immunoglobulin (h & l) or biotiny ... | 1989 | 2541152 |
| demonstration of bovine virus diarrhoea virus antigen in formalin fixed, paraffin embedded tissue using a streptavidin/biotin technique. | the detection of bovine virus diarrhoea virus (bvdv) antigen in sections from formalin fixed, paraffin embedded tissue is described. pre-digestion of the sections with 0.02 per cent protease xiv for 18 hours at 4 degrees c is necessary to unmask formalin fixed antigen. a hyperimmune antiserum prepared in a pig, using a combination of bvdv and hog cholera virus inoculations, linked to a biotinylated anti-pig/streptavidin peroxidase detection system demonstrated antigen in a wide range of tissues ... | 1989 | 2544973 |
| hog cholera virus--characterization of specific antiserum and identification of cdna clones. | a specific antiserum was raised against the pestivirus inducing hog cholera (hog cholera virus, hcv). using immunoprecipitation and sds-page, this antiserum served for comparison of hcv-induced proteins with those from a related and better characterized pestivirus, bovine viral diarrhea virus (bvdv). in addition to immunological relationships, the apparent molecular weights of some proteins induced by both viruses were quite similar. hcv genomic rna was found to be about 12 kb in length, compara ... | 1989 | 2545029 |
| characterization of porcine and some ruminant pestiviruses by cross-neutralization. | serologic relationships between 11 pestivirus strains that originated from pigs and five that originated from cattle or sheep were studied by cross-neutralization. experiments were performed with pig and sheep sera raised against the strains. the results were analysed by a computerized taxonomic procedure. the 16 viruses were classified into four distinct serologic groups. all hog cholera virus (hcv) strains were classified in one group; the other three groups consisted of strains that can infec ... | 1989 | 2552645 |
| general characteristics and viral susceptibility of a newborn pig kidney (npk) continuous culture. | we have developed a fibroblastic-like continuous culture of newborn pig kidney (npk). the current cell line was serially passaged 160 times and appeared to be well suited for production and assay of a number of viruses affecting pigs, such as pig parvovirus, pseudorabies and transmissible gastroenteritis. the cell line appeared aneuploid, with a modal chromosome number of 36 and induced tumors, classified as fibrosarcoma, in athymic mice. | 1989 | 2555655 |
| antigenic differentiation of pestivirus strains with monoclonal antibodies against hog cholera virus. | thirty-one bovine viral diarrhoea virus (bvdv) or border disease virus (bdv) strains and 94 hog cholera virus (hcv) strains were grown in cell culture, and characterized by immunostaining with 13 monoclonal antibodies (mabs) and one polyclonal serum (pab) against hcv. all 125 strains were recognized by the pab. none of the bvdv or bdv strains were detected by the 13 mabs. seven mabs detected all 94 hcv strains. six other mabs detected heterogeneity among and within hcv strains. the mabs are usef ... | 1989 | 2560281 |
| diversity of african swine fever virus. | an african swine fever virus is an heterogeneous population, consisting of clones having different biological characteristics in respect to hemadsorption, virulence, infectivity, plaque size, and antigenic determinants. the following observations were made: nonhemadsorbing virus (nhv) have been segregated from field isolates from haiti (ht-1) and a bone marrow- and buffy coat-passaged portuguese isolate (l'60bm89bc1) and appear as a major, minor, or equal mixture with hemadsorbing viruses in the ... | 1985 | 2581483 |
| [molecular characterization of the hog cholera virus]. | the molecular biology of hog cholera virus (hcv) was studied. after reverse transcription of the viral rna the cdna was cloned in the expression vector lambda gt11. hcv clones were identified using antibodies as a probe. partial sequencing of one hcv-derived cdna clone revealed a high degree of homology to a portion of the bovine viral diarrhea virus (bvdv). one goal of these studies is the preparation of defined, effective and safe vaccines against pestiviruses. | 1989 | 2590156 |
| in vitro transcription by cytoplasmic extracts from cells infected with african swine fever virus. | a cell-free system for the study of transcription of african swine fever virus (asfv) mrna was developed from cytoplasmic extracts of infected cells permeabilized with lysolecithin. extracts prepared from infected cells early and late after infection incorporated [alpha-32p]utp into acid-insoluble material that was resistant to dnase and sensitive to rnase. the incorporation was inhibited by actinomycin d but not by alpha-amanitin. the presence of the nuclei was not required. in vitro transcript ... | 1989 | 2596035 |
| experimental infection of pregnant goats with swine fever virus. | thirteen pregnant goats were inoculated intravenously with the ald strain of virulent swine fever (sf) virus on days 64-84 of gestation. dams showed transient and mild viremia, and produced high serum neutralizing (sn) antibody after inoculation. six inoculated dams were reared until parturition occurred and bore six apparently normal, one apparently normal but dead, one mummified and three edematous kids. neutralizing antibody was demonstrated in the pre-colostral sera obtained from all normal ... | 1989 | 2672548 |
| antibodies to bovine serum albumin in swine sera: implications for false-positive reactions in the serodiagnosis of african swine fever. | antibodies to bovine serum albumin were detected in swine sera by use of an immunoblotting technique. such sera had false-positive reactions, as determined by results of african swine fever virus serodiagnostic techniques when bovine serum albumin was a contaminant in the soluble cytoplasmic antigen obtained from infected cells cultured in the presence of bovine serum. the soluble cytoplasmic antigen obtained from cell cultures infected with african swine fever virus in the presence of porcine s ... | 1989 | 2672914 |
| infection of pigs with the cameroon isolate (cam/82) of african swine fever virus. | african swine fever (asf) was produced in eight pigs by exposure to donors infected with the cameroon/82 isolate of african swine fever virus. the primary clinical sign was pyrexia of more than 40 degrees c first observed 10 to 13 days post-exposure (dpe) in all pigs; other clinical signs were rarely observed. the most frequent post-mortem lesion was haemorrhage in the visceral lymph nodes. other lesions included excess fluid in the abdominal cavity and petechial haemorrhages in the kidneys. vir ... | 1989 | 2715397 |
| gly-gly-x, a novel consensus sequence for the proteolytic processing of viral and cellular proteins. | three african swine fever virus structural proteins of relative molecular weights 150,000, 37,000, and 34,000 (p150, p37, and p34) are derived from precursors with relative molecular weights 220,000, 60,000, and 39,000 (pp220, pp60, and pp39) by proteolytic cleavage after the second gly residue in the sequence gly-gly-ala/gly. a search of the national biomedical research foundation data bank revealed that several adenovirus proteins, ubiquitin, and an interferon-induced 15-kda protein are also d ... | 1989 | 2722819 |
| a study of african swine fever virus infected ticks (ornithodoros moubata) collected from three villages in the asf enzootic area of malawi following an outbreak of the disease in domestic pigs. | a detailed study was made in 1983-5 in three villages in mchinji district in the african swine fever (asf) enzootic area of malawi, following an outbreak of asf which affected all three villages. ticks of the ornithodoros moubata complex were collected from both pig sties and houses shortly after the outbreak, and approximately 24% contained asf virus. the proportion of ticks infected did not differ significantly in the three villages, or more surprisingly in different types of premises, and was ... | 1989 | 2737257 |
| the entry of african swine fever virus into vero cells. | the entry of african swine fever virus into vero cells has been investigated by both biochemical and morphological techniques. a quantitative electron microscopy analysis of the early steps of the infection has shown that african swine fever virus enters vero cells by a receptor-mediated endocytosis mechanism. the internalization of virus particles is a temperature- and energy-dependent process, since it did not take place at 4 degrees or in the presence of naf and 2,4-dinitrophenol. to determin ... | 1989 | 2741349 |
| molecular cloning and nucleotide sequence of the genome of hog cholera virus. | a cdna clone derived from genomic rna of hog cholera virus (hcv) was identified using an oligonucleotide complementary to the rna encoding a hexapeptide from the putative rna-dependent rna polymerase of the closely related bovine viral diarrhea virus (bvdv). this clone served as a probe for screening different size-selected cdna libraries. after molecular cloning and nucleotide sequencing the hcv genome was shown to consist of 12,284 nucleotides containing one long open reading frame. sequence c ... | 1989 | 2763466 |
| clearance of african swine fever virus from infected tick (acari) colonies. | three laboratory colonies of the argasid tick onithodoros moubata porcinus van der merwe were started from collections made in 1983 at three different sites in zimbabwe. all of the colonies contained ticks infected with african swine fever (asf) virus that was readily transmitted by bite to domestic pigs. although they were maintained on virus-free pig blood, asf virus infections persisted in the colonies for at least 1 yr. despite the fact that asf virus passes transstadially, sexually, and tra ... | 1989 | 2769711 |
| virus-specific cellular blastogenesis and interleukin-2 production in swine after recovery from african swine fever. | animals recovered from viral diseases represent an important model to study the host cellular and humoral immune responses to the etiologic agents. this is particularly important for african swine fever virus (asfv) infections in which antibodies have little or no virus-neutralizing effect. pigs surviving experimental infection with the naturally occurring low-virulent, nonhemadsorbing asfv/nh/p68 (nhv) isolate did, however, exhibit virus-specific t-cell activities, as measured by a variety of a ... | 1989 | 2802312 |
| genetic variation of african swine fever virus: variable regions near the ends of the viral dna. | restriction endonuclease maps of the variable dna regions of african swine fever virus field isolates from the iberian peninsula showed that the changes in length are located in the terminal-inverted repetitions and in unique sequences close to the dna ends. analysis of nine clones derived from the spleen of an infected pig revealed the existence of frequent length changes within the inverted terminal repetitions. in each clone, changes occurred symmetrically at both terminal-inverted repetition ... | 1989 | 2815584 |
| mechanical transmission of capripox virus and african swine fever virus by stomoxys calcitrans. | stomoxys calcitrans can act as an efficient mechanical vector of capripox virus and african swine fever virus. capripox virus was transmitted to a susceptible goat by flies infected 24 hours previously and the virus survived in some flies for at least four days. african swine fever virus was transmitted to susceptible pigs by flies infected one hour and 24 hours previously and the virus survived in these flies for at least two days without apparent loss of titre. | 1987 | 2820006 |
| genome analysis of african swine fever virus isolated in italy in 1983. | an african swine fever virus (asfv) isolated in an 1983 outbreak of the disease in piemonte, italy, was related by restriction endonuclease analysis of the viral genome to asfv strains isolated in the dominican republic (1978), haiti (1981) and cameroon (1982). | 1987 | 2821672 |
| physical characterization of the genome of a cattle isolate of capripoxvirus. | hindiii, pstl, aval, and sali site maps have been determined for the genome of a cattle isolate of capripoxvirus, kc-1. the length of the genome was estimated, by summation of the lengths of individual hindiii fragments, to be 145.6 kb, and the genome was shown to possess terminally repeated regions 1.13-6.23 kb in length. the restriction site maps demonstrate that the genome of kc-1 does not possess a high degree of nucleotide sequence homology with the genomes of isolates of orthopoxvirus, par ... | 1987 | 2821685 |
| african swine fever virus dna: deletions and additions during adaptation to growth in monkey kidney cells. | restriction enzyme cleavage maps for the fragments produced by cla i, sal i and sma i have been constructed for african swine fever virus (asfv) dna grown in pig leukocytes (strain e70 l6) and after adaptation to growth in ms monkey kidney cells (strain e70ms14). the mapping data revealed that before adaptation to growth in ms cells, the size of the dna from asfv strain e70 l6 was l73 kbp and after adaptation it was only l56 kbp. the decrease in size was produced by deletions and additions mainl ... | 1987 | 2827611 |
| [transmission of pestiviruses between animal species: experimental infection of swine with the virus of bovine virus diarrhea (bvd) and of cattle with the virus of european swine fever (esp)]. | | 1987 | 2827988 |
| use of enzyme-linked immunosorbent assays in diagnosis of viral diseases in domestic livestock. | | 1987 | 2829767 |
| genetic stability of african swine fever virus grown in monkey kidney cells. brief report. | viral dna subpopulations were produced when the asfv was grown in monkey kidney ms cells. they were detected after 44 passages but not during the first 14 passages or in the unadapted asfv e 70 strain grown in pig leukocytes. different viral variants were isolated and their genomes were characterized. restriction enzyme site variations were detected in both terminal fragments, cla i-m and sal i-f, and in the internal fragments clal-o and sma i-h. these variations result in changes in the size of ... | 1988 | 2829794 |
| neutralizing antibody development following sequential inoculation of pigs with strains of bovine viral diarrhea virus and hog cholera virus. | | 1987 | 2830743 |
| [lyophilized combined live vaccine against swine fever and aujeszky's disease]. | | 1987 | 2831830 |
| antiviral activity of uridine 5'-diphosphate glucose analogues against some enveloped viruses in cell culture. | twenty five analogues of uridine 5'-diphosphate glucose were screened against herpes simplex type 2, vaccinia virus, sindbis virus and african swine fever virus. after screening, the compound 5'-[[[[(2",3",4",6"-tetra-o-benzoyl-alpha-d- glucopyranosyl)oxi]carbonyl]amino]sulfonyl]uridine (2), the synthesis of which has been reported (camarasa et al., j. med. chem. 28, 40-46, 1985), was selected for further study. this compound showed in vitro activity against all viruses tested. the replication o ... | 1987 | 2837144 |
| identification of hog cholera viral isolates by use of monoclonal antibodies to pestiviruses. | a collection of 90 field isolates of hog cholera virus (hcv) was used to test the specificity of four hybridoma cell lines secreting monoclonal antibodies against pestiviruses. reaction of virus isolates and monoclonal antibodies was controlled by an indirect immunofluorescence assay (ifa). two monoclonal antibodies which had been generated against hc virus strain "alfort 187" were reactive only with hcv field isolates and an hcv reference strain but not with bovine viral diarrhoea virus (bvdv) ... | 1988 | 2837867 |
| molecular cloning and restriction enzyme mapping of an african swine fever virus isolate from malawi. | dna prepared from a field isolate of african swine fever virus, which causes high mortality and severe disease in domestic pigs, was cloned in bacteriophage lambda and plasmid vectors. clones containing dna inserts overlapping with each other and together covering the complete genome, apart from short fragments close to the cross-linked termini of the genome, were obtained. a complete restriction enzyme site map of the genome for three enzymes was deduced. | 1988 | 2839602 |
| characteristics of the porcine kidney cell line ib-rs-2 clone d10 (ib-rs-2 d10) which is free of hog cholera virus. | a brazilian stock of clone c17 of the ib-rs-2 porcine kidney cell line which was contaminated with hog cholera virus (hcv) was cloned. one clone designated ib-rs-2 d10 was determined to be free of hcv, 20 other viruses, and mycoplasma. ib-rs-2 d10 cells possessed the same viral susceptibility pattern as the contaminated parent cells to the viruses of foot-and-mouth disease, swine vesicular disease, vesicular exanthema of swine, transmissible gastroenteritis, and several other viruses. the ib-rs- ... | 1988 | 2840431 |
| natural infections of pigs with bovine viral diarrhoea virus associated with signs resembling swine fever. | between 1976 and 1985 while using immunofluorescence in the laboratory diagnosis of swine fever (sf), 13 incidents of bovine viral diarrhoea virus (bvdv) infection were detected in the netherlands. ultimate differentiation between swine fever virus (sfv) and bvdv was based on herd evidence supported by comparative antibody studies on sera from pigs inoculated with the isolate and from contact pigs in the herd of origin, using reference strains of sfv and bvdv. recently differentiation of sfv and ... | 1988 | 2848298 |
| bovine viral diarrhoea virus infections in piglets born to sows vaccinated against swine fever with contaminated vaccine. | on eight farms a congenital pestivirus infection in piglets was detected which could be traced to vaccination of the dams against swine fever (sf). viruses isolated from the piglets were not recognised by monoclonal antibodies (mcas) against swine fever virus (sfv) and were shown to be bovine viral diarrhoea virus (bvdv) or border disease virus. the expected 'chinese' strain of sfv could not be demonstrated in the batch of vaccine that had been used on these farms. instead, a contaminating pesti ... | 1988 | 2848299 |
| the application of monoclonal antibody panels to characterize pestivirus isolates from ruminants in great britain. | monoclonal antibodies were prepared against bovine virus diarrhoea virus and hog cholera virus. they were used to test 101 field isolates of ruminant pestivirus in a simple binding assay using an indirect immunoperoxidase label on fixed cell cultures. the monoclonals were divided into three panels: (1) pestivirus group specific, (2) hog cholera specific, (3) selectively reactive with ruminant pestiviruses. the reaction patterns with panel 3 were analyzed by a computer spreadsheet to determine th ... | 1988 | 2849388 |
| african swine fever virus and aids. | | 1986 | 2869298 |
| aids and african swine fever virus. | | 1986 | 2876270 |
| a rapid serum neutralization test in microplates for the detection of antibodies to hog cholera virus. | the fluorescent antibody serum neutralization (fasn) test for the detection of antibodies to hog cholera virus was developed utilizing 96-well and terasaki microplates. this microtechnique, especially when performed in terasaki plates, offers some advantage if compared with conventional fasn in coverslip cell cultures, being easier and more rapid, saving of reagents and allowing simple microscopic observation. | 1989 | 2913021 |
| detection of african swine fever virus antibodies by immunoblotting assay. | an immunoblotting assay has been adapted to detect antibodies against african swine fever virus. the electrophoretic transfer of proteins and the immunoreaction conditions were optimized, using 4 ma/cm2 of current intensity and 10 micrograms of soluble cytoplasmic antigen of infected cells per strip. filters of polyvinylidene difluoride showed the highest capacity for protein absorption, but nitrocellulose filters showed lower backgrounds. the specificity and the pattern of the proteins induced ... | 1989 | 2914218 |
| saturable binding sites mediate the entry of african swine fever virus into vero cells. | binding experiments of 3h-labeled african swine fever virus to susceptible vero cells have shown the presence of saturable binding sites for african swine fever virus on the plasma membrane. the scatchard analysis of the binding data at equilibrium indicates the existence of about 10(4) cellular receptor sites per cell with a dissociation constant (kd) of 70 pm. virus entry into vero cells is mediated by a saturable component, since tritiated african swine fever virus saturable binding and uptak ... | 1989 | 2916331 |
| african swine fever virus-induced proteins on the plasma membranes of infected cells. | the african swine fever virus-induced proteins on plasma membranes of infected cells have been studied by two different procedures, iodination and incubation of infected cells labeled with [35s]methionine with a specific antiserum, obtained from pigs immunized with a monkey stable cell-adapted african swine fever virus. the combined use of both procedures identified proteins ip56, ip51, ip35, ip34, ip31, ip30, ip25.5, ip23.5, ip16, ip15, ip14, and ip12 as viral antigens exposed on the surface of ... | 1989 | 2916332 |
| morphological study on the entry of african swine fever virus into cells. | the early interactions between african swine fever virus (asfv) and monkey kidney cells in culture, and the effect of chloroquine were studied by electron microscopy. our results indicate that asfv uptake occurs by endocytosis: after attachment to the cell surface, the virions were seen in coated pits and were internalized by endocytosis in endosomes and finally in lysosomes. virions in coated vesicles were never seen. all these steps were completed in about 15 min. direct penetration of viruses ... | 1985 | 2937495 |
| [simultaneous vaccination against aujeszky's disease and european hog cholera]. | | 1985 | 2986592 |
| screening for neutralizing antibodies against hog cholera- and/or bovine viral diarrhea virus in danish pigs. | | 1985 | 2994428 |
| preliminary serological characterization of bovine viral diarrhoea virus strains using monoclonal antibodies. | five monoclonal antibodies against the bovine viral diarrhoea (bvd) viral strain nadl were isolated and characterized by an indirect immunofluorescence assay. extensive cross-reactions were detected when the antibodies were tested with 12 heterologous bvd and four hog cholera (hc) viral strains. one antibody reacted with all strains tested. two antibodies were specific for cytopathogenic bvd viruses, but failed to react with hc virus. the other antibodies reacted to varying degrees with bvd and ... | 1986 | 3022462 |
| detection of antibodies against african swine fever virus using infected monolayers and monoclonal antibodies. | three monoclonal antibodies, specific for porcine igg, igm and iga, were used to develop isotype-specific immunoperoxidase monolayer assays for the detection of antibodies against african swine fever virus. a mixture of anti-igm and anti-igg monoclonal antibodies was used in an assay designed for screening sera. this test was compared with a commercially available elisa by using experimental sera and field sera obtained after an outbreak of african swine fever on two farms in the netherlands in ... | 1988 | 3046107 |
| [the biochemistry of the african swine fever virus]. | | 1988 | 3046133 |
| a study on the susceptibility of minipig kidney (mpk) and rabbit kidney (rk13) cell line cultures to the lapinized chinese strain of hog cholera virus. | the susceptibility of two established cell lines of pig (mpk = minipig kidney) and rabbit (rk13 = rabbit kidney) origin to the lapinized chinese (lc) strain of hog cholera virus (hcv) was studied. spleen cells from rabbits infected with the virus under study were inoculated to cell cultures of either mpk and rk13 cells and subsequent passages were made by culturing the trypsinized infected cells with the normal cells. only the mpk cell line appeared to be susceptible to virus replication. since ... | 1988 | 3063925 |
| proteins specified by african swine fever virus: v. identification of immediate early, early and late proteins. | autoradiographic analysis of polypeptides separated by polyacrylamide gel electrophoresis revealed that, after infection with asfv, ms cells synthesized at least 44 new polypeptides, that could be classified as immediate early, early or late proteins. a new viral polypeptide (ip 78) was detected by treatment of cells with cycloheximide for 14 hours. | 1987 | 3101652 |
| detection of dna viruses by radioactive and non radioactive dna probes: application to african swine fever virus. | a molecular hybridization technique using radioactive and non radioactive dna probes, has been used to detect asfv dna immobilized on nitrocellulose paper. it is based on the use of plasmid prpel-2 as a hybridization probe. this plasmid contain the h-clai dna fragment (size 5.6 kbp) from the spain-70 strain of asfv. the sensitivity of detection using radioactive 32p-probes (specific activity about 2 x 10(8) cpm per microgram) was about 20 pg of viral dna. the 32p-prpel-2 dna probe can detect abo ... | 1987 | 3101653 |
| phosphorylation of african swine fever virus proteins in vitro and in vivo. | highly purified african swine fever virus contains a cyclic amp-independent protein kinase which phosphorylates endogenous virus proteins with a specific activity of about 0.45 pmol/microgram of virus protein. the major substrates for the virion protein kinase in vitro were the structural proteins p10 and p9. both proteins were phosphorylated preferentially at serine residues. a possible relationship between protein p10 phosphorylation and rna synthesis in vitro by the virion-associated rna poly ... | 1988 | 3139081 |
| effect of interferon-alpha, interferon-gamma and tumour necrosis factor on african swine fever virus replication in porcine monocytes and macrophages. | bovine interferon-alpha i1 (ifn-alpha i1) and porcine interferon-gamma (ifn-gamma) inhibited african swine fever virus replication in both porcine monocytes and alveolar macrophages. the most potent antiviral activity was observed with ifn-gamma-treated alveolar macrophages. the production of both a virulent (cc83) and a non-virulent (ba71) isolate of the virus was inhibited. bovine tumour necrosis factor alpha did not show antiviral activity in either monocytes or alveolar macrophages. rather, ... | 1988 | 3143809 |
| susceptibility of a minipig kidney cell line (mpk) to hog cholera virus. | a comparitive study on the different susceptibility of mpk cells (minipig kidney cell line) and pk15 cells (pig kidney cell line) to the hog cholera virus (hcv) was conducted. higher hcv titres (3 log10) were reached on mpk cells compared with pk15 cells. | 1988 | 3173126 |
| [immunomorphological studies of swine vaccinated with an attenuated vaccine against swine fever]. | | 1988 | 3178400 |
| genetic diversity of african swine fever virus isolates from soft ticks (ornithodoros moubata) inhabiting warthog burrows in zambia. | the genomes of african swine fever virus isolates collected from soft ticks (ornithodoros moubata) inhabiting warthog burrows in four areas of zambia were compared by restriction enzyme site mapping. isolates from different areas showed considerable diversity. the regions of genomes that differed between isolates were distributed throughout the virus genome, although some more conserved regions were identified, such as the right-hand third of the genome. the genomes of seven isolates from neighb ... | 1988 | 3199101 |
| association of african swine fever virus with the cytoskeleton. | the association of african swine fever virus (asfv) with the cytoskeleton was investigated. immunofluorescent studies of asfv infected cells with anti-asfv serum showed a temporal and spatial development of viral inclusions which moved from a peripheral to a perinuclear location and fused to give a single large perinuclear factory. the migration and fusion of viral inclusions was inhibited by colchicine suggesting a function for microtubules in assembly site organization not previously described ... | 1988 | 3201825 |
| a protein of molar mass 12 kda incorporates into the membrane of asf virus-infected cells. | an african swine fever virus-induced protein of molar mass 12 kda (p12) was studied in virus-infected vero cells using the monoclonal antibody 18b.b11. protein p12 is incorporated into the membrane of infected cells about 7 h post-infection and is not present in purified african swine fever virus particles. the synthesis of protein p12 is sensitive to cytosine arabinoside. | 1988 | 3201826 |
| the distribution of african swine fever virus isolated from ornithodoros moubata in zambia. | african swine fever (asf) has been reported in the eastern province of zambia since 1912 and is now considered to be enzootic there. a survey of the distribution of asf virus in zambia was carried out by virus isolation from ornithodoros moubata ticks collected from animal burrows in national parks and game management areas in northern, eastern, central and southern zambia. asf virus was isolated from ticks in all areas examined. the prevalence of infection in o. moubata was between 0.4% in sout ... | 1988 | 3215286 |
| hog cholera virus: identification and characterization of the viral rna and the virus-specific rna synthesized in infected swine kidney cells. | virus-specific rna in swine kidney cells infected with hog cholera virus and the rna of gradient-purified virions were identified and characterized. the time curve for virus replication in sk-6 cells was established. the logarithmic phase of virus growth was between 4 and 12 h after virus adsorption. virus production was maximum at 20 h after virus adsorption. analysis of cytoplasmic rna in a neutral agarose gel showed that the time curve for synthesis of a high molecular weight rna in infected ... | 1988 | 3223061 |
| mapping and sequence of the gene encoding protein p37, a major structural protein of african swine fever virus. | the gene encoding protein p37, one of the major structural proteins of african swine fever (asf) virus has been mapped and sequenced. protein p37 was obtained from purified virions and the first 27 amino acids from its nh2-terminal end were identified by automatic edman degradation. to map the gene encoding protein p37, a mixture of 20-mer deoxyoligonucleotides based upon a part of this amino acid sequence was hybridized to cloned asf virus restriction fragments. this allowed localization of the ... | 1988 | 3245132 |
| correlation between b-cell mitogenicity and immunosuppressor effects of a protein released by porcine monocytes infected with african swine fever virus. | virus-free supernatants of cultured swine monocytes infected by african swine fever virus (asfv) suppressed in vitro proliferation of porcine and human blood mononuclear cells in response to phytohemagglutinin and the in vivo primary immune response of c57bl/6 mice against sheep rbc. the supernatants were fractionated by discontinuous ion-exchange chromatography and subfractionated by double-step preparative isoelectric focusing. the pool of the most purified active subfractions (f5'ep-asfv) is ... | 1988 | 3266831 |
| the protective value of vaccine-induced neutralising antibody titres in swine fever. | the relationship between vaccine-induced antibody titres against swine fever virus (sfv), as measured by the neutralisation peroxidase-linked assay (npla), and protection against virus multiplication, excretion and transmission, disease and death was studied in 46 pigs. the pigs were housed individually and challenged intranasally with 100 pig id50 of the virulent brescia strain of sfv. in order to detect virus transmission, a swine fever (sf)-susceptible sentinel pig was placed in contact with ... | 1988 | 3287757 |
| an enzyme-linked immunosorbent assay (elisa) for detection of antibodies against swine fever virus using horseradish-peroxidase-protein-a as conjugate. | | 1988 | 3289886 |
| double labeling immunohistological study of african swine fever virus-infected spleen and lymph nodes. | to identify cells in situ in which african swine fever (asf) virus is present, a double immunohistological labeling technique was used on sections of asf-infected spleen and lymph nodes. cells were identified by an indirect immunoalkaline phosphatase technique using monoclonal antibodies (moab) reactive against different leukocyte subsets. asf virus, detected by a direct immunoperoxidase method using swine immunoglobulin g (igg) anti-asf virus antigens, was not present in t helper or in t cytoto ... | 1988 | 3293303 |
| a hemolymph test for the detection of african swine fever virus in ornithodoros coriaceus (acari: argasidae). | | 1987 | 3295242 |
| prospects for the use of embryos in the control of disease and the transport of genotypes. | transfer and low temperature storage of embryos are now proven techniques for a number of mammalian species. these techniques are useful in control of disease and in saving genotypes from infected animals. the place of embryos in the epidemiology of disease depends upon whether the causative organism can gain entry to the oocyte before or at fertilisation and on whether the young embryo can be invaded by organisms in the uterine environment. there is little evidence that important live-stock dis ... | 1987 | 3297016 |
| hog cholera virus: art and facts. | the aim of this review is to summarize the informations accumulated during the two last decades on hog cholera virus, a member of the pestivirus genus. different aspects concerning the virus-host cell interactions, and the structural and antigenic properties of the virion itself are successively analyzed. despite numerous works, many basic informations are still lacking, which can be explained by the difficulties inherent to the study of this virus. | 1987 | 3304110 |
| cytopathogenic effect of african swine fever virus for pig monocytes: characterization and use in microassay. | a microculture assay is described for the titration of african swine fever virus (asfv) using swine monocytes contained in mononuclear leucocyte (mnl) microcultures. titration endpoints were determined by observing cytopathogenic effects (cpe) of asfv infected monocytes with an inverted microscope at 40 x magnification. cpe was a late event following the detection of asfv antigens in monocytes by radioimmune assay, immunofluorescence and hemadsorption. it began with the detachment, enlargement a ... | 1987 | 3307125 |
| [cultivation and demonstration of the classic swine fever virus]. | experiments were carried out for the cultivation and indication of the swine pestivirus in several continuous and in primary cell lines, using lapinized and field strains of the virus. it was demonstrated that in the various cell cultures the strains used showed varying rates of growth. in pk-15 and pig embryonic kidney cell lines, the field strains and the virulent vratsa strain replicated with no preliminary adaptation, forming numerous large fluorescent plaques at the 16th to 18th hour. in th ... | 1987 | 3307133 |
| the host response to african swine fever virus. | | 1987 | 3310105 |
| inhibition of virus replication in the tonsils of pigs previously vaccinated with a chinese strain vaccine and challenged oronasally with a virulent strain of classical swine fever virus. | after an oronasal (o.n.) infection with classical swine fever (c.s.f.) virus, virus multiplication can be detected in the tonsils from day 2 post infection (p.i.) till death. the course of viral replication during the first 10 days after o.n. challenge exposure of pigs, previously vaccinated with a chinese strain vaccine in the presence or absence of maternal antibodies, was studied using direct immunofluorescence techniques on cryostat sections and virus isolations. when piglets were challenged ... | 1987 | 3310377 |
| potential arthropod vectors of african swine fever virus in north america and the caribbean basin. | in an effort to identify arthropods that might serve as vectors and perhaps reservoirs of african swine fever virus (asfv) if it were to enter the u.s.a., the blood-sucking insect triatoma gerstaeckeri and four species of ticks of the genus ornithodoros were established in colonies capable of reproducing in numbers sufficient to enable thorough studies to be made of their asfv vector potentials. a nymphal stage of t. gerstaeckeri carried the virus for 41 days and retained it through one molt, bu ... | 1987 | 3326244 |
| correlations between titres from direct immunofluorescence and bioassay for assessment of potency of "celvivac" swine fever live vaccine. | | 1987 | 3327482 |
| moderately virulent african swine fever virus infection: blood cell changes and infective virus distribution among blood components. | blood samples of pigs infected with a moderately virulent african swine fever virus (asfv) isolate, obtained from the dominican republic (dr-ii), were monitored temporally for viremia, infective asfv association with major blood components, differential changes in blood cell composition, and plasma antibodies to asfv. after intranasal/oral virus inoculation, pigs underwent acute infection and illness that resolved. acute illness began on postinoculation day (pid) 4 and continued to pid 11, and p ... | 1988 | 3358545 |
| effect of inhibitors of the host cell rna polymerase ii on african swine fever virus multiplication. | the role of the host cell rna polymerase ii in african swine fever (asf) virus growth has been examined using inhibitors of this enzyme. the adenosine analog 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole (drb), an inhibitor of mrna precursor synthesis in mammalian cells, strongly inhibits the production of infectious progeny virus in vero cells, but does not significantly affect the synthesis of virus-specific macromolecules. on the other hand, virion assembly seems to proceed normally in the ... | 1988 | 3363868 |
| classical swine fever: virulence and tissue distribution of a 1986 english isolate in pigs. | following the recurrence of classical swine fever in the united kingdom in 1986, a virus isolated from a single outbreak was studied. a major factor in the spread of this disease is considered to be the presence of infectious virus in tissues taken from animals at certain stages of infection, although their condition may escape detection by routine inspection either before or after slaughter. intranasal inoculation of the isolate into eight-week-old pigs reproduced the acute form of the disease. ... | 1988 | 3394221 |
| inhibition of african swine fever virus dna synthesis by (s)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine. | the acyclic nucleotide analogue (s)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(s)-hpmpa] is a potent and selective inhibitor of african swine fever virus (asfv) replication. using the dna-dna hybridization technique with plasmid prpel-2 as probe, we have shown that (s)-hpmpa exerts a specific, dose-dependent, inhibitory effect on viral dna synthesis. also, (s)-hpmpa inhibits the production of late viral proteins, especially ip-73, in asfv-infected ms and vero cells. when evaluated under th ... | 1988 | 3395330 |
| a model virus-cell system to study the persistence of african swine fever virus. | the persistence of african swine fever virus (asfv) on vero cells was induced by using 5-iodo-2'-deoxyuridine (idu). after the persistence was established, several cycles of decreasing virus production were observed with intervals in which no virus could be detected. these latency-like periods could last from 15 to 25 days. after three and a half months the cells appeared to be "cured" and no virus was detected during almost three years. these "cured" cells (vero-l) were more resistant to superi ... | 1988 | 3401116 |
| isolation of african swine fever virus from ticks of the ornithodoros moubata complex (ixodoidea: argasidae) collected within the african swine fever enzootic area of malawi. | ticks of the ornithodoros moubata complex were collected from domestic pig sties and dwelling houses, and from a warthog habitat, and tested for the presence of african swine fever (asf) virus. collections were made in 9 of the 24 districts of malawi, these being primarily the districts in which o. moubata is most numerous. asf virus was isolated from ticks collected in both domestic pig sties and houses in certain villages in mchinji district where asf outbreaks had recently occurred. mchinji d ... | 1988 | 3402546 |
| outbreaks of classical swine fever in great britain in 1986. | classical swine fever was confirmed in 10 herds in britain between april 10 and june 25, 1986 and typical acute disease was seen in nine of them. serological evidence of exposure to classical swine fever virus was found in a further seven herds which, together with another nine, were slaughtered as dangerous contacts. altogether 7781 pigs in 26 herds were slaughtered at a cost of 450,101 pounds for compensation alone. in order to detect subclinical disease, the majority of traced herds were bloo ... | 1988 | 3420768 |
| [development, status and responsibilities in control and immunoprevention of swine fever in east germany]. | | 1987 | 3442451 |
| [effective preventive dose of riems swine fever vaccine for aerogenic immunization]. | | 1987 | 3442453 |