| 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 |
| detection of african swine fever virus by a biotinylated dna probe: assay on cell cultures and field samples. | african swine fever virus was detected in various samples using a molecular hybridization technique. a fragment located in a constant area of the viral genome was biotin-labelled. this probe, when present at a concentration of 100 ng/ml of the hybridization solution, could detect 10 pg of target dna immobilized on nitrocellulose with cellular dna and rna. the virus was evidenced after being passaged on monkey kidney cells, either 8 h post-inoculation (pi) if the multiplicity of infection (moi) w ... | 1991 | 1897870 |
| 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 |
| 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 |
| antiviral activity of sulfated polysaccharides against african swine fever virus. | the polyanionic substances lambda and kappa carrageenan, pentosan polysulfate, fucoidan, dextran sulfate and heparin were investigated for their inhibitory effect on the replication of african swine fever virus (asfv) in vitro. lambda carrageenan was the most efficacious with a selectivity index, as based on the ratio of the 50% cytotoxic concentration to the 50% antiviral effective concentration, of 120, followed by pentosan polysulfate with 30, kappa carrageenan 13.3 and fucoidan 10. dextran s ... | 1991 | 1713439 |
| mapping and molecular characterization of a functional thymidine kinase from amsacta moorei entomopoxvirus. | a thymidine kinase (tk) gene from the entomopoxvirus of amsacta moorei (amepv) has been identified, mapped, cloned, and sequenced. the amepv tk was shown to be biologically functional as cloning of the gene into a tk-derivative of the orthopoxvirus vaccinia creates a tk+ virus. the gene has been localized to a 1.5-kb ecori-q dna fragment which maps to the far left end of the viral genome. sequence analysis reveals an open reading frame (orf) of 182 amino acids potentially encoding a polypeptide ... | 1992 | 1733099 |
| 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 |
| 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 |
| 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 |
| experimental african swine fever: evidence of the virus in interstitial tissues of the kidney. | | 1989 | 2711573 |
| interferon-gamma production by african swine fever virus-specific lymphocytes. | peripheral blood mononuclear cells (pbmc) from inbred pigs that were immunized with autologous macrophages infected with the african swine fever (asf) virus ba71v, a nonvirulent virus isolate, proliferated and produced interleukin-2 in response to homologous and heterologous isolates of the asf virus. they produced, however, interferon (ifn) only when challenged in vitro with homologous or attenuated isolates of the asf virus, but not with heterologous or virulent isolates. the ifn was ph 2 labi ... | 1992 | 1738818 |
| 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 |
| 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 sequences of the ribonucleotide reductase genes from african swine fever virus show considerable homology with those of the orthopoxvirus, vaccinia virus. | two african swine fever virus (asfv) recombinant plasmids containing large inserts of dna have been sequenced at random, and translations of the dna sequence have been compared to libraries of vaccinia virus protein sequences. among other genes identified by their extensive homology with vaccinia virus genes were the large and small subunits of ribonucleotide reductase. a 5.5-kb fragment from the malawi (lil20/1) strain of asfv was identified as containing the genes for both these subunits. the ... | 1991 | 1871976 |
| 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 |
| 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 |
| 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 |
| 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 |
| in vitro dna replication by cytoplasmic extracts from cells infected with african swine fever virus. | a cell-free system that catalyzes dna replication was prepared from cytoplasmic extracts of vero cells infected with african swine fever virus (asfv). the cells were permeabilized with lysolecithin and disrupted by mild mechanical action and the nuclei were removed by low-speed centrifugation. extracts prepared from infected cells at the time of maximal dna replication incorporated [alpha-32p]dttp into acid-insoluble material that was sensitive to dnase and resistant to rnase. the reaction was i ... | 1990 | 2219742 |
| african swine fever virus and aids. | | 1986 | 2869298 |
| african swine fever and aids. | | 1986 | 2873310 |
| aids and african swine fever virus. | | 1986 | 2876270 |
| 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 |
| african swine fever virus fatty acid acylated proteins. | labeling experiments with [3h]palmitic and [3h]myristic acids of african swine fever virus-infected vero cells have shown that 11 proteins induced during infection are covalently bound to myristic acid and that palmitic acid was not attached to viral proteins. the time course of synthesis of the myristylated polypeptides and the requirements of viral dna replication indicated that the myristylated proteins, with the exception of a 13-kda protein, belong to the late class of viral proteins. the m ... | 1991 | 1962463 |
| 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 |
| 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 |
| expression and characterization of the thymidine kinase gene of african swine fever virus. | the thymidine kinase (tk) gene of african swine fever virus (asfv) was located within the viral genome by using two degenerate oligonucleotide probes derived from sequences of the vaccinia virus and cellular tk genes. the tk gene was mapped within a 0.72-kbp bglii-xhoi fragment (0.242 to 0.246 map units) derived from a 23.9-kbp sali-b fragment of the asfv genome. identification of this region as the asfv tk gene was confirmed by expression of tk in escherichia coli and by the synthesis of active ... | 1991 | 1987368 |
| 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 |
| protein p22 of african swine fever virus: an early structural protein that is incorporated into the membrane of infected cells. | the open reading frame k'177, located at the left end of the african swine fever virus genome, codes for an early induced structural protein of 22,000 da (p22), which is released from the viral particle by the nonionic detergent n-octyl-beta-d-glucopyranoside under conditions that solubilize external viral structural proteins. the predicted amino acid sequence of the protein contains a hydrophobic region at its n-terminus with characteristics of a signal peptide and, at early times after virus i ... | 1991 | 1994575 |
| 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 |
| 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 |
| african swine fever virus attachment protein. | treatment of african swine fever virus particles with nonionic detergents released proteins p35, p17, p14, and p12 from the virion. of these proteins, only p12 bound to virus-sensitive vero cells but not to virus-resistant l or ibrs2 cells. the binding of p12 was abolished by whole african swine fever virus and not by similar concentrations of subviral particles that lacked the external proteins. a monoclonal antibody (24bb7) specific for p12 precipitated a protein that, when analyzed by sodium ... | 1991 | 2016759 |
| a hemolymph test for the detection of african swine fever virus in ornithodoros coriaceus (acari: argasidae). | | 1987 | 3295242 |
| role of b and t lymphocytes in the specific immunosuppression induced by a protein released by porcine monocytes infected with african swine fever virus. | some immunobiological aspects of host responses to an immunosuppressive protein (p36) released by porcine monocytes upon infection with african swine fever virus were analysed in a murine system. treatment of normal, adult c57bl/6 mice with p36 (i) significantly delayed allogenic skin graft rejection; (ii) suppressed the specific plaque-forming cell response to immunization with heterologous erythrocytes; but (iii) induced marked increases in the numbers of 'background' splenic ig-secreting plaq ... | 1991 | 2025617 |
| 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 |
| the host response to african swine fever virus. | | 1987 | 3310105 |
| inhibition of african swine fever virus in cultured swine monocytes by phosphonoacetic acid (paa) and by phosphonoformic acid (pfa). | the use of phosphonoacetic (paa) and phosphonoformic acid (pfa) as inhibitors of african swine fever virus (asfv) replication in porcine monocytes/macrophages (mo) was investigated. at concentrations sufficient to inhibit replication, hemadsorption, and cytopathogenic damage by high inocula of asfv, both antiviral agents were cytostatic and suppressed the dna-synthetic growth response of porcine mo to the mo-specific colony-stimulating factor-1 (csf-1). paa and pfa inhibited asfv-associated dna- ... | 1990 | 2148081 |
| 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 |
| interferon cures cells lytically and persistently infected with african swine fever virus in vitro. | human interferon alpha (ifn-alpha) and interferon gamma (ifn-gamma) inhibit african swine fever (asf) virus replication in vero cells. ifn-alpha and ifn-gamma exert a synergistic inhibition. human tumor necrosis factor (tnf) does not inhibit asf virus replication in this cell line, but in combination with ifns it has antiviral enhancing activity. analysis of the mechanism of inhibition suggests that the action of these cytokines blocks a step that comes prior to dna replication. the 2'-5' a synt ... | 1990 | 1695091 |
| comparison of two antigens for use in an enzyme-linked immunosorbent assay to detect african swine fever antibody. | two african swine fever virus (asfv) antigens were tested for use in an elisa to detect antibody to asfv. antigens used were the cytoplasmic soluble fraction (cs-p) of infected cells grown in the presence of porcine serum and the semipurified viral structural protein vp73 (svp73). both antigens were tested by elisa against 72 sera obtained during several asf field episodes and from asfv-inapparent carriers. of the 72 sera, only 2.8% has positive results by elisa against cs-p antigen; 60% of posi ... | 1990 | 2240773 |
| 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 |
| phosphonylmethoxyalkylpurines and -pyrimidines as inhibitors of african swine fever virus replication in vitro. | several phosphonylmethoxyalkylpurine and -pyrimidine derivatives related to (s)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(s)-hpmpa] and 9-(2-phosphonylmethoxyethyl)adenine (pmea) were evaluated as inhibitors of african swine fever virus (asfv) replication in vero cells. (s)-hpmpa has previously been shown to inhibit asfv replication at a minimum inhibitory concentration (mic) of 0.01 microgram/ml with a selectivity index of 15000. of the new compounds tested, the following emerged as the ... | 1987 | 3451699 |
| comparative efficacy of broad-spectrum antiviral agents as inhibitors of african swine fever virus replication in vitro. | various nucleoside analogues, selected on the basis of their previously established broad-spectrum antiviral properties, were evaluated for their potency and selectivity as inhibitors of the in vitro replication of the iridovirus, african swine fever virus (asfv). the test compounds included (s)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine [(s)-hpmpa], 9-(2-phosphonylmethoxyethyl)adenine, (rs)-3-adenin-9-yl-2-hydroxypropanoic acid isobutyl ester, (s)-9-(2,3-dihydroxypropyl)adenine, carbocyclic ... | 1987 | 3475038 |
| modulation of porcine peripheral blood-derived macrophage functions by in vitro infection with african swine fever virus (asfv) isolates of different virulence. | macrophages play an important role in defense against invading pathogens and neoplastic diseases. their ability to maintain their functional characteristics is also important in the survival of the host. loss of macrophage function during infection may be important in determining resistance or susceptibility of a host species. in this communication, we describe the effect of asfv replication, in macrophages in vitro, on the functional characteristics of these cells. infection with asfv did not a ... | 1987 | 3509675 |
| production of monoclonal antibodies specific for african swine fever virus following in vitro primary immunization of mouse splenocytes in the presence of stimulated t lymphocyte supernatants. | splenocytes from non-immune mice were stimulated in vitro using a kit of cytokine preparations (obtained from murine mlr and el-4 cell cultures), and concomitantly immunized with african swine fever (asf) virus antigen. in addition, fusions were performed at 5 days after primary or secondary stimulation/immunization. the detection of specific antibodies in the culture supernatants was not successful. in contrast, specific antibody-producing hybridomas could be generated, and this was at least co ... | 1991 | 1765668 |
| [african swine fever in the netherlands]. | african swine fever (asf) was diagnosed for the first time in the netherlands on a farm near the hague, illegally feeding swill from hospitals, hotels and restaurants. laboratory diagnosis was based initially on the indirect immunofluorescence test (ift) and the immunoperoxidase monolayer assay (ipma) for antibodies in tissue extracts and later on confirmed by the direct-ift on cryostat sections, animal inoculation and haemadsorption. clinical signs and post-mortem lesions were consistent with t ... | 1986 | 3518145 |
| inhibitory effect of african swine fever virus on lectin-dependent swine lymphocyte proliferation. | the incubation of swine peripheral blood mononuclear cells (pbmc) with african swine fever (asf) virus preparations strongly inhibited the proliferative response of lymphocytes to pha and other lectins. the inhibition, which persisted after inactivation of the virus by uv radiation, was dependent upon the dose and the time that virus preparations were present in cultures. when virus preparations were fractionated by ultracentrifugation, the inhibitory activity resulted to be soluble, whereas no ... | 1990 | 2251767 |
| in vitro and in vivo association of african swine fever virus with swine erythrocytes. | the association of african swine fever virus (asfv) with swine erythrocytes in vivo, in high titers, was verified by inoculating 30 pigs with 17 asfv isolates and assaying their plasma and washed erythrocyte fractions for residual virus. viral antigens were specifically localized on the surface of in vitro and in vivo swine erythrocytes, using the fluorescent antibody technique and 3 monoclonal antibodies specific for asfv. the same monoclonal antibodies immunoprecipitated virus-specific polypep ... | 1986 | 3521406 |
| identification of african swine fever viral antigens in the hemolymph of soft ticks (argasidae: ornithodoros) by the immunodot blot test. | the immunodot blot test was used to identify african swine fever virus (asfv) antigens in the hemolymph from soft ticks (ornithodoros coriaceus) fed on asfv-infected pigs. the immunodot blot test was sensitive and specific for asfv antigens and has potential field application. hemolymph from field-collected ticks can be screened for asfv and a variety of other tick-borne pathogens using this test. | 1986 | 3532842 |
| glomerular pathology in surviving pigs experimentally infected with african swine fever virus. | twelve miniature pigs were inoculated with an attenuated african swine fever virus to study glomerular involvement in surviving pigs. in acute phase, kidneys were severely affected and displayed a glomerular capillary thrombosis with fibrin deposition in vascular lumen, detected by immunofluorescence. fibrin-positive deposits were progressively cleared between one to three months after infection in surviving pigs. the histological picture in kidneys of surviving pigs, up to one post-infection ye ... | 1991 | 1806048 |
| effect of macrophage-specific colony-stimulating factor (csf-1) on swine monocyte/macrophage susceptibility to in vitro infection by african swine fever virus. | swine cells of the monocyte/macrophage lineage (mm) proliferate and survive for several weeks in vitro in medium supplemented with the murine macrophage-specific hematopoietic growth factor, colony-stimulating factor 1 (csf-1). the extent to which mm, cultured in csf-1, supported african swine fever virus (asfv) growth in vitro was investigated. mm, cultured in medium with csf-1, were sensitive to infection and viral-induced cytopathogenic damage by both natural field isolates of asfv and fibrob ... | 1990 | 2281603 |
| genetic variation and multigene families in african swine fever virus. | the genome of a virulent strain (lis57) of african swine fever virus differs from that of the vero-cell-adapted strain (ba71v) in several deletions located in the variable regions. the region which contains the most differences is located 8-20 kb from the left end. the dna sequence of this region was obtained from lis57 virus dna and compared with the overlapping sequences of ba71v virus. this comparison revealed that the changes in the variable regions result in differences in the number of gen ... | 1990 | 2219721 |
| multigene families in african swine fever virus: family 110. | the genome of african swine fever virus was screened for the existence of repetitive sequences by hybridization between different cloned restriction fragments covering the viral dna. several sets of repeated sequences were detected in fragments located close to the dna ends. one of these groups of repetitions involved fragments located at both ends of the genome. the remaining groups involved fragments that were located exclusively at the left end. the sequence of a 3.2-kilobase segment spanning ... | 1990 | 2325202 |
| proteins synthesized in african swine fever virus-infected cells analyzed by two-dimensional gel electrophoresis. | at least 74 acidic and 37 basic proteins are synthesized in african swine fever virus (asfv)-infected monkey cells not detected in uninfected cells analyzed by two-dimensional gel electrophoresis. essentially all the proteins synthesized early during infection are also observed at late times. the use of inhibitors such as cycloheximide and phosphonoacetate has led to the identification of 34 immediate early and 13 delayed early polypeptides. therefore 64 proteins were classified as late polypept ... | 1987 | 3629977 |
| in vitro immune serum-mediated protection of pig monocytes against african swine fever virus. | serum samples from pigs that had recovered from infection with a dominican republic isolate of african swine fever virus (asfv) were mixed with dilutions of the virus, then assayed in microcultures of normal pig mononuclear leukocytes to determine whether the samples contained antibodies that protected monocytes against the virus. protection was determined by the difference in titer (log10) between virus mixed with healthy pig serum and virus mixed with immune pig serum, using 50% cytopathogenic ... | 1987 | 3631688 |
| ultrastructure of the liver in pigs with experimental african swine fever. | | 1987 | 3672813 |
| multigene families in african swine fever virus: family 360. | a group of cross-hybridizing dna segments contained within the restriction fragments rk', rl, rj, and rd' of african swine fever virus dna were mapped and sequenced. analysis of these sequences revealed the presence of a family of homologous open reading frames in regions close to the dna ends. the whole family is composed of six open reading frames with an average length of 360 coding triplets (multigene family 360), four of which are located in the left part of the genome and two of which are ... | 1990 | 2325203 |
| mapping and sequence of the gene coding for protein p72, the major capsid protein of african swine fever virus. | the gene encoding protein p72, the major structural protein of african swine fever virus and one of the most immunogenic proteins in natural infection has been mapped and sequenced. the gene was mapped by using oligonucleotide probes deduced from amino acid sequences of tryptic peptides obtained from purified protein p72. this allowed the location of the gene in fragment ecori b of african swine fever virus dna. the nucleotide sequence obtained from this region revealed an open reading frame enc ... | 1990 | 2327074 |
| 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 |
| inactivation and inhibition of african swine fever virus by monoolein, monolinolein, and gamma-linolenyl alcohol. brief report. | monoolein, monolinolein and (most strongly) gamma-linolenyl alcohol inactivate asf virus and inhibit its replication in vero cells at 25 micrograms/ml while at 10 micrograms/ml no inactivation occurs but inhibition of replication in tissue culture is observed. this suggests two possibly different action mechanisms. | 1986 | 3707358 |
| 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 |
| 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 |
| 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 |
| 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 |
| inhibition of african swine fever infection in the presence of immune sera in vivo and in vitro. | in assay cultures, sera from african swine fever convalescent pigs inhibited infection by homologous african swine fever virus. the infection-inhibition capacity did not correspond with the virus-neutralizing capacity. the serum did not prevent infection by heterologous virulent viruses. sera from pigs challenge inoculated with the homologous virulent virus and later with a heterologous virulent virus inhibited the infection by different heterologous virulent viruses. these sera did not interfer ... | 1986 | 3729125 |
| 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 |
| hblv is not asfv. | | 1988 | 3196489 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| an immunological approach to vaccines against african swine fever virus. | until recently there were no published reports of any immunological mechanism which could curtail the replication of african swine fever virus (asfv). we have now described three such mechanisms--complement dependent lysis, antibody dependent cellular cytotoxicity and cytotoxic t lymphocytes. this paper discusses the likely role which each might play during asfv infection and indicates where this research might help with a disease where no effective vaccine is available. | 1985 | 3873757 |
| 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 |
| comparative ultrastructure of iridoviridae. | | 1985 | 3893905 |
| african swine fever virus. | | 1985 | 3893908 |
| the epidemiology of african swine fever: the role of free-living hosts in africa. | the known distribution of african swine fever (asf) virus in africa is reviewed in relation to the distributions of its free-living hosts as are the infection rates of these species in different localities in southern africa. mechanisms by which asf virus is maintained in its sylvatic state and ways in which the infection may enter domestic pig populations are discussed. | 1985 | 3911134 |
| application of prpel2 plasmid to detect african swine fever virus by dna-dna hybridization. brief report. | a diagnostic assay has been developed to detect african swine fever virus in field samples. it is based on the use of 32p-dna from prpel2 plasmid as a hybridization probe. this plasmid contains essentially the h-clai dna fragment from the spain-70 strain of african swine fever virus. | 1986 | 3942504 |
| purification and properties of african swine fever virus. | we describe a method for african swine fever (asf) virus purification based on equilibrium centrifugation in percoll density gradients of extracellular virions produced in infected vero cells that yielded about 15 +/- 9% recovery of the starting infectious virus particles. the purified virus preparations were essentially free of a host membrane fraction (vesicles) that could not be separated from the virus by previously described purification methods. the purified virus sedimented as a single co ... | 1985 | 3989907 |
| effect of chloroquine on african swine fever virus infection. | when present during the whole infective cycle, the lysosomotropic drug, chloroquine, inhibited cytopathic changes and production of african swine fever virus (asfv) in vero cells. this inhibition decreased when the drug was added from 1 h to 4 h after infection. chloroquine had no effect on the virus nor on viral adsorption and internalization. electron microscopy showed that, in the presence of the drug, the virions were retained in large vacuoles having a lysosomal appearance. this inhibition ... | 1985 | 3998709 |
| the role of antibody in protection against african swine fever virus. | intraperitoneal immunization of pigs with anti-african swine fever virus (asfv) antibody protected them against the effects of challenge with asfv. this protection, which was exemplified by a reduction in pyrexia and viraemia plus an increased survival time, appeared to be mediated through the effects of complement-dependent antibody-mediated cytotoxicity (cdac) or antibody dependent cell mediated cytotoxicity (adcc). experiments suggested that the reduction in viraemia was associated with compl ... | 1985 | 4035978 |
| monoclonal antibodies against african swine fever viral antigens. | monoclonal antibodies specific for african swine fever (asf) viral proteins of 14, 32, 73, 174, and 240 kda were produced and characterized. immunoelectron microscopy detected the 73 kda but not the 14-, 32-, or 240-kda proteins at the surface of the virion. the 32-kda protein was detected by radioimmunoassay 2 hr after infection of porcine monocytes and vero cells, was detected in the seven widely divergent asfv isolates tested, and stained brilliantly virus-infected cells in indirect immunoflu ... | 1985 | 4060578 |
| mechanism of thrombocytopenia in african swine fever. | pigs were inoculated with an african swine fever (asf) isolate of moderate virulence, and the changes in the number of circulating blood platelets during infection were correlated with the appearance of antiviral antibody and fluctuations in total plasma hemolytic complement concentrations. thrombocytopenia was detected by postinoculation days (pid) 7 and 8, and antiviral antibody was detected by pid 7, using an indirect immunofluorescence technique. the total hemolytic complement concentration ... | 1985 | 4062007 |
| polypeptides and structure of african swine fever virus. | extracellular and intracellular african swine fever virus (asfv) was purified using a two-phase aqueous polymer system. both the structure of the virus and the polypeptides present during the purification procedure were studied. after peg/dextran phase separation and centrifugation through 20% (w/v) ficoll, 79% of input infectivity was recovered as semi-purified virus. the density of the virus after equilibrium centrifugation in sucrose was 1.19 g/ml. the envelope of the virion consisting of a u ... | 1985 | 4072397 |
| experimental transmission of african swine fever virus by ornithodoros savignyi (audouin). | the 'sand tampan', ornithodoros savignyi, is susceptible to oral infection with african swine fever (asf) virus in the laboratory. infected ticks can transmit the virus transstadially and are able to maintain it for at least 106 days. transmission of asf virus by infected ticks to healthy pigs was achieved on five separate occasions between 50 and 106 days after infection. pigs infected in this way developed typical acute african swine fever. the distribution of o savignyi in africa suggests tha ... | 1985 | 4081341 |
| chemical structure of african swine fever virus investigated by electron microscopy. | | 1967 | 4168517 |