| replication of african swine fever virus in cell cultures. | infection-specific, nonstructural, african swine fever virus antigens, as visualized by the immunofluorescence technique, appeared as fine stipplings, evenly distributed in the cytoplasm and nucleus of vero cells and in monocytes by postinoculation hour (pih) 3. cytoplasmic inclusion bodies (ib) appeared at pih 4 and continued to increase in size up to pih 8. the viral dna was solely synthesized within the ib of infected monocytes, as evidenced by an autoradiographic chase experiment; maximum sy ... | 1980 | 7004279 |
| field evaluation of enzyme-linked immunosorbent assay for detection of antibody to african swine fever virus. | the enzyme-linked immunosorbent assay (elisa) for detection of antibodies to african swine fever virus was evaluated under field conditions in the dominican republic. a total of 3,402 swine serums were tested by elisa. all elisa-positive serums (n = 224) and 426 of 2,760 elisa-negative serums were retested by indirect immunofluorescence (iif). there were no antibodies to asf virus detected by iif in elisa-negative serums. by iif, antibodies were detected in only a small portion of the elisa-posi ... | 1981 | 7027849 |
| african swine fever: a reassessment. | | 1981 | 7034503 |
| a reliable enzyme linked immunosorbent assay for african swine fever using the major structural protein as antigenic reagent. | | 1981 | 7034688 |
| inactivation of african swine fever virus in tissues by gamma radiation. | | 1982 | 7046538 |
| complement-mediated lysis of african swine fever virus-infected cells. | using an homologous pig system, th lysis of african swine fever virus-infected cells by antibody and complement was investigated. the optimal conditions necessary for lysis are described, and it was found that the system was unique amongst reported virus infections in that infected cells were lysed by the classical complement pathway and not the alternative pathway. development of antibody capable of initiating complement-mediated lysis was relatively late in the infected pig, although functiona ... | 1982 | 7076281 |
| production and titration of african swine fever virus in porcine alveolar macrophages. | the broncho-alveolar lavage of a pig (20-40 kg) contains about 1.6 x 10(9) alveolar cells, half of which were macrophages. the number of cells in the lavage of bacille calmette guerin (bcg)-treated pigs increased about 4-fold. both african swine fever virus-infected porcine alveolar macrophages and blood monocytes produced about 1000 hemadsorption units/cell, a value 10-fold larger than that obtained in virus-infected vero cells. porcine alveolar cells could be stored frozen and, after thawing, ... | 1982 | 7085838 |
| the immunological response of pigs and guinea pigs to antigens of african swine fever virus. | pigs vaccinated with glutaraldehyde-fixed alveolar macrophages (am) infected with african swine fever virus (asfv) had an accelerated serological response after subsequent challenge and a slight reduction in levels of viraemia. vaccination of pigs with detergent-treated infected am produced no detectable serological response and no protection against homologous challenge. guinea pigs were vaccinated with glutaraldehyde-fixed asfv-infected cells, detergent-treated infected cells, detergent-treate ... | 1982 | 7165511 |
| western hemisphere isolates of african swine fever virus: asymptomatic carriers and resistance to challenge inoculation. | convalescent clinically normal pigs were tested for the persistence of african swine fever (asf) infection. one group of pigs was examined 135 days after inoculation with a brazilian isolate and a 2nd group was examined 110 days after inoculation with a dominican republic isolate. susceptible pigs exposed by contact to these groups remained clinically normal. these contact pigs plus 2 more pigs added to each group developed asf after being fed and inoculated with tissues collected from recovered ... | 1980 | 7212418 |
| sedimentation coefficient of african swine fever virus. | the sedimentation coefficient of the infective unit of african swine fever in tissue culture harvest fluids was measured in a preparative ultracentrifuge. the boundary locator method used also permitted making an estimate of heterogeneity. the sedimentation coefficient ranged from 3,000 to 8,000 svedberg units, representing many classes of infective particles. electron microscopy on culture fluids from infected cells showed many kinds of virus-containing units. sucrose-cscl gradient centrifugati ... | 1980 | 7212420 |
| photographic defocusing: a means to render recognizable line traced models of negatively stained biological specimens. | a simple method of obtaining analogue images from traced models of biological specimens is presented. it consists of the photographic defocusing of traced models and it is illustrated with negatively stained cylindrical forms of the asfv; the black lines of the trace in the model correspond to the negative stain surrounding the viral morphological subunits as seen in the electron micrograph. the photographic defocusing is the means by which the traced model is filtered and is used to introduce g ... | 1981 | 7241589 |
| [use of the hemadsorption method to demonstrate the african swine fever virus in angola]. | attempts were made to modify the hemadsorption method used in the demonstration of the african swine fever virus. use was made of fourteen strains of the virus with known hemadsorption properties and infectious titers, which were replicated in leukocyte cultures of swine blood, in three variants: (a) at direct infection of the cultures without changing the medium; (b) at infecting with changing the medium and adding erythrocytes to the new medium; and (c) infecting the cultures with changing the ... | 1981 | 7303482 |
| induced african swine fever in feral pigs. | feral pigs trapped in florida were exposed by intranasal/oral inoculation or contact to african swine fever virus isolants from the iberian peninsula and the dominican republic. all exposed pigs became sick and died or were killed after becoming moribund. necropsy revealed lesions typical of african swine fever, but several pigs had marked hemorrhage surrounding the kidneys or rectum or in the gastric, hepatic, or ventral abdominal region that, in the field, might have suggested trauma or poison ... | 1981 | 7309606 |
| african swine fever virus (malta/78) in pigs. | | 1981 | 7345110 |
| dna-dependent rna polymerase in african swine fever virus. | | 1980 | 7355576 |
| a microtechnique for the titration for african swine fever virus. | african swine fever virus isolates were titrated in swine monocyte cultures established in microtitre trays. although technically simpler and less laborious than conventional tube assays the microtitration assay was less sensitive, but for routine and comparative titrations offers distinct advantages. | 1980 | 7377975 |
| experimental transmission of african swine fever virus by ornithodoros coriaceus, an argasid tick indigenous to the united states. | three ticks, indigenous to the united states, were assessed for their ability to maintain and transmit african swine fever virus (asfv). amblyomma americanum and a cajennense adults and nymphs maintained virus for 4 to 7 days after engorging on infected swine blood; however, virus was not carried through the subsequent molt of nymphs and it was not transmitted vertically to the eggs and larvae of the infected females. on refeeding of the ticks, infection was not transmitted to healthy swine. orn ... | 1980 | 7406278 |
| lymphocyte responses to african swine fever virus infection. | the immunological response of pigs infected with african swine fever virus was related to both quantitative and qualitative changes in the lymphocyte population. the cytolytic effect of the virus on lymphocytes caused a proportionally greater drop in b cell than in t cell numbers. a blastogenic test was developed to measure the appearance of specifically sensitised lymphocytes in the circulation. these appeared about 10 days after infection in animals infected with attenuated virus; pigs infecte ... | 1980 | 7414064 |
| proteins specified by african swine fever virus. i. analysis of viral structural proteins and antigenic properties. | at least 28 polypeptides have been identified in intracellular virus, with molecular weights ranging from 11,500 to 243,000 daltons. by treatment with nonidet p-40 and 2-mercaptoethanol it is possible to obtain subviral particles that have lost some proteins and have a density in cscl of 1.31 g/cm3 which is higher than that of the complete virus (1.23 g/cm3). after addition of nacl the virus loses its major protein vp73 which indicates that it is localized in the viral envelope. cores obtained a ... | 1980 | 7436740 |
| experimental infection of warthos (phacochoerus aethiopicus) with african swine fever virus. | although there were no obvious signs of illness following experimental infection of young warthog with african swine fever virus, the animals developed viraemias between 10(2,4) and 10(3,6) hd50/ml within the first week of infection, and virus concentrations in a number of lymphatic tissues attained high levels (greater than or equal to 10(6) hd50/g). unlike in blood, and to some extent in the spleen, virus titres in lymph nodes did not decline appreciable during the 33-day observation period, s ... | 1980 | 7454231 |
| a simplified method for detection of african swine fever antibodies by immunoelectroosmophoresis. | | 1980 | 7459509 |
| synthesis of substituted 1-norbornylamines with antiviral activity. | the reaction of (+/-)-camphor (7) with triflic anhydride (tf2o) yields the bridgehead triflate 8. the nametkin rearrangement of 8 to 3 was realized by treatment with triflic acid (tfoh). the solvolysis of the bridgehead triflates 3 and 8 in acetonitrile affords the n-acetyl-1-norbornylamines 4 and 9. the pd(0)-catalyzed hydrogenation of 4 and 9 gives the amides 5 and 10. the corresponding 1-norbornylamines 2 and 13 and the n-ethyl derivatives 1, 6, 11, and 12 were obtained by basic hydrolysis or ... | 1995 | 7473574 |
| [localizing the major peptides of african swine fever virus and virus-associated enzymes in the virion structure]. | african swine fever virus polypeptides with molecular weight of 120, 78, 69, 59, 56, 45, 39, 28, 26, 24, 16, and 14 kd are the major proteins in the purified virions, as shown by electrophoresis and immunoblotting. a mixture of proteases and pancreatic lipase hydrolyzed the polypeptides of 120 and 78 kd in viral preparations at low concentrations of enzymes, polypeptides of 69, 56, 45, 39, 28, and 14 kd disappeared after treatment with this mixture at medium concentrations, and 26 kd polypeptide ... | 1995 | 7477038 |
| [apoptosis in the african swine fever virus-swine mononuclear phagocyte system]. | routine electronmicroscopic examination of interactions between african swine fever virus and mononuclear phagocytes showed signs of apoptosis as a morphological phenomenon and form of cellular death in an infected culture treated with defective interfering virus particles and in target cells under the effect of virus specific cytotoxic t-lymphocytes. the morphology of induced apoptosis in the aforesaid virus-cell system is illustrated and described in detail. | 1995 | 7477039 |
| african swine fever virus structural protein p72 contains a conformational neutralizing epitope. | we have previously described a monoclonal antibody (mab 135d4) to an unidentified 70- to 72-kda african swine fever virus (asfv) protein that exhibited high levels of neutralizing activity against various virulent asfv isolates. here, we identify the reactive asfv protein as the major virus structural protein p72. in vitro-translated products of the p72 protein gene were specifically immunoprecipitated by mab 135d4. immunoprecipitation of a nested set of truncated p72 in vitro translation produc ... | 1994 | 7514322 |
| uses of flow cytometry in virology. | this article reviews some of the published applications of flow cytometry for in vitro and in vivo detection and enumeration of virus-infected cells. sample preparation, fixation, and permeabilization techniques for a number of virus-cell systems are evaluated. the use of flow cytometry for multiparameter analysis of virus-cell interactions for simian virus 40, herpes simplex viruses, human cytomegalovirus, and human immunodeficiency virus and its use for determining the effect of antiviral comp ... | 1994 | 7530594 |
| pathological changes in the renal interstitial capillaries of pigs inoculated with two different strains of african swine fever virus. | african swine fever is a viral disease of pigs characterized predominantly by haemorrhagic lesions. this paper reports the lesions observed in the renal interstitial capillaries of pigs inoculated with african swine fever virus strains of differing virulence: the malawi'83 strain (haemadsorbent and highly virulent) and the dominican republic'78 strain (haemadsorbent and moderately virulent). in pigs infected with the malawi'83 strain, petechial haemorrhages and microhaemorrhages were observed 5 ... | 1995 | 7560303 |
| experimental african swine fever: apoptosis of lymphocytes and virus replication in other cells. | in order to determine the cause of cellular death of lymphocytes in pigs with acute african swine fever and the relationships between african swine fever virus (asfv) and interstitial cells, ten pigs were inoculated with a highly virulent strain of asfv (malawi '83) and samples taken for ultrastructural study of hepatic and renal interstitial tissues. we demonstrated death by apoptosis of lymphocytes and virus replication in fibroblasts, smooth muscle cells and endothelial cells in the interstit ... | 1995 | 7561784 |
| inactivation of viruses in liquid manure. | the stability of some viruses and methods of virus inactivation in liquid manure are reviewed. the authors discuss experimental data on the stability of foot and mouth disease virus, classical swine fever virus, aujeszky's disease virus, african swine fever virus, swine influenza virus, porcine paramyxovirus, bovine virus diarrhoea virus and transmissible gastroenteritis of pigs virus. recommendations and practical advice are given for the choice and application of chemical disinfectants for slu ... | 1995 | 7579641 |
| inhibition of il-2r and sla class ii expression on stimulated lymphocytes by a suppressor activity found in homogenates of african swine fever virus infected cultures. | virus free supernatants (vfs) obtained by ultracentrifugation of homogenates of african swine fever (asf) virus infected cultures inhibited the proliferative response and the expression in peripheral blood mononuclear cells of two activation molecules, the il-2 receptor (il-2r) and the swine mhc class ii antigens (sla ii), induced by several stimuli (lectins, pma plus the calcium ionophore a23187 or specific antigen). this inhibition was time dependent: no effect was seen on il-2r expression whe ... | 1995 | 7611879 |
| vectors for the genetic manipulation of african swine fever virus. | plasmid vectors designed to facilitate the genetic manipulation of african swine fever virus (asfv) are described. our results demonstrate that the beta-glucuronidase enzyme (gus) can be used to follow gene expression in asfv-infected cells. infectious plaques formed by asfv expressing gus are visually detectable, thus providing a simple and highly sensitive method for the selection of asfv recombinants. these and previous results have allowed us to construct two chimeric gene cassettes that con ... | 1995 | 7612241 |
| production and purification of recombinant african swine fever virus attachment protein p12. | the conditions for cultivation of spodoptera frugiperda (sf9) insect cells for production of recombinant baculoviruses have been studied, to scale-up and improve the efficiency of the process for production of the african swine fever virus attachment protein p12 in the baculovirus expression system. it was shown that the total virus and recombinant protein production in insect cells infected with the acp12 recombinant baculovirus were slightly dependent on cell density, but largely dependent on ... | 1995 | 7612242 |
| isolation and characterization of tk-deficient mutants of african swine fever virus. | african swine fever virus induces the synthesis of thymidine kinase (tk) in bhk tk-negative cells as an immediate early protein. the tk gene is not essential for growth of asfv in cell culture and a stable viral strain deficient in tk has been isolated (e70ntkp). the genetic lesion of this asfv tk- strain was identified by tk gene nucleotide sequencing, showing a nucleotide deletion leading to a -1 frameshift and a nonsense codon residue downstream of the deletion. the availability of this viabl ... | 1995 | 7625127 |
| localization of the african swine fever virus attachment protein p12 in the virus particle by immunoelectron microscopy. | the african swine fever virus attachment protein p12 was localized in the virion by immunoelectron microscopy. purified virus particles were incubated, before or after different treatments, with p12-specific monoclonal antibody 24bb7 and labeled with protein a-colloidal gold. untreated virus particles showed labeling only in lateral protrusions that followed the external virus envelope. mild treatment of african swine fever virions with the nonionic detergent octyl-glucoside or with ethanol onto ... | 1993 | 7679861 |
| virulent african swine fever virus isolates are neutralized by swine immune serum and by monoclonal antibodies recognizing a 72-kda viral protein. | convalescent swine serum to african swine fever virus (asfv) isolate e75 neutralized the infectivity of virulent asfv isolates e75, e70, lisbon 60, malawi lil 20/1 and a low passage tissue culture adapted variant of e75, e75cv/v3, by 86-97% in vero and macrophage cell cultures. a monoclonal antibody, mab-135d4, recognizing an asfv protein of 72 kda also exhibited strong neutralizing activity with these viruses. unexpectedly, both e75 immune sera and mab-135d4 failed to neutralize high passage ti ... | 1993 | 7690502 |
| [glycoproteins from the african swine fever virus]. | the composition of african swine fever virus (asfv) glycoproteins was studied. isolate-specific major gp 110-140 was identified by radioimmunoprecipitation in lysate of porcine bone marrow cells infected with hemadsorbing virus strains. carbohydrates constitute about 50% of the total mass of gp 110-140. a quantitative method is proposed for identification of the serologic relationships between asfv hemadsorbing strains. a possible role of asfv glycoprotein carbohydrates in the hemadsorption, vir ... | 1994 | 7716925 |
| african swine fever virus gene j13l encodes a 25-27 kda virion protein with variable numbers of amino acid repeats. | the african swine fever virus (asfv) j13l gene encodes a 177 amino acid protein (19.0 kda) with a putative transmembrane domain between residues 32 and 52. there is a potential signal peptide cleavage site at residue 54 and several possible motifs for phosphorylation and myristylation. rabbit antisera raised against a synthetic peptide from the c terminus of the j13l orf identified proteins of 25-27 kda in cells infected with a recombinant vaccinia virus expressing the j13l orf, in asfv-infected ... | 1995 | 7730797 |
| ultrastructural study of the renal tubular system in acute experimental african swine fever: virus replication in glomerular mesangial cells and in the collecting ducts. | despite the considerable attention given to kidney lesions in african swine fever (asf), a number of questions remain to be answered. structural and ultrastructural examination showed that a highly virulent isolate of asf virus (malawi 83) replicated in glomerular mesangial cells and renal collecting duct epithelial cells, with hyperplasia of the latter in infected pigs. replication in mesangial cells may be due to their contact with the bloodstream, as well as to their phagocytic capacity and h ... | 1995 | 7733828 |
| the role of fibrinolysis in the pathogenesis of the haemorrhagic syndrome produced by virulent isolates of african swine fever virus. | the activity of several proteins involved in fibrinolysis and the morphological changes in the blood vessel walls of pigs infected with highly virulent (malawi'83) and moderately virulent (dominican republic '78-dr'78) asf virus isolates were determined. pigs infected with the malawi'83 virus developed an increased fibrinolytic activity due to high plasma levels of tissue-plasminogen activator (t-pa) of 71.3 +/- 22.8 iu/ml (mean +/- sd), which correlated well with an increased activation of inte ... | 1995 | 7740481 |
| promoter analysis of an african swine fever virus gene encoding a putative elongation factor. | | 1995 | 7758704 |
| highly specific confirmatory western blot test for african swine fever virus antibody detection using the recombinant virus protein p54. | a western blot technique using a recombinant protein has been developed to confirm positive results obtained in african swine fever (asf)-specific antibody detection by elisa. the new confirmatory western blot is based on the use of protein p54, one of the most antigenic asf virus structural proteins, expressed in escherichia coli fused to the n-terminus of ms2 polymerase. the recombinant western blot assay was highly specific and equally sensitive for asf virus-infected pigs detection as the co ... | 1995 | 7769024 |
| a comparison of three avidin-biotin complex immunoenzyme systems for detection of african swine fever virus antigen in paraffin-embedded tissues. | the sensitivity and specificity of 3 avidin-biotin complex (abc) immunostaining systems were compared on paraffin-embedded tissues from african swine fever virus (asfv)-infected pigs. results were also compared with immunofluorescent detection on cryosections of the same tissue for optimal detection of asfv antigen. the abc-alkaline phosphatase (abc-ap) and abc-peroxidase (abc-po) systems were at least as sensitive as direct fluorescent antibody (fa) and 10-fold more sensitive than the abc-gluco ... | 1995 | 7779959 |
| early infection of interdigitating dendritic cells in the pig lymph node with african swine fever viruses of high and low virulence: immunohistochemical and ultrastructural studies. | the role of interdigitating dendritic cells (idcs) in the early pathogenesis of african swine fever (asf) was investigated using mandibular lymphoid tissue from normal pigs and pigs inoculated oronasally with highly virulent lisbon 60 (l-60) and moderately virulent dominican republic 1979 (dr-2) asf virus (asfv) isolates. paraffin-embedded tissue sections were immunostained for asfv antigen and s-100 protein, a marker of idcs, using an avidin-biotin alkaline phosphatase procedure. swine idcs wer ... | 1995 | 7779960 |
| african swine fever interference with foot-and-mouth disease infection and seroconversion in pigs. | initial oral infection of pigs with either highly virulent (l-60) or moderately virulent (dr-2) african swine fever virus (asfv), followed in 3 days with exposure to foot-and-mouth disease virus (fmdv) (tongue inoculation and contact), failed to cause fmdv infection or seroconversion in 18 of 22 l-60-infected pigs and 13 of 34 dr-2-infected pigs. of the 13 dr-2-infected pigs remaining free of foot-and-mouth disease (fmd), 2 pigs survived to 24 days without antibody to fmdv, despite constant cont ... | 1995 | 7779962 |
| african swine fever virus infection of skin-derived dendritic cells in vitro causes interference with subsequent foot-and-mouth disease virus infection. | highly purified skin-derived dendritic cells (sddcs) isolated from swine skin by a simple novel method were cultured for 24 hours before independent or sequential inoculation with african swine fever virus (asfv) and foot-and-mouth disease virus (fmdv). by avidin-biotin immunohistochemical staining, asfv antigen was detected in 50% of sddcs as early as 1.5 hours postinfection (hpi) and in 80% by 3 hpi when cytopathic effect was noted. cell lysis was detected with fmdv infection as early as 8 hpi ... | 1995 | 7779963 |
| characterization of a ubiquitinated protein which is externally located in african swine fever virions. | an antiserum was raised against the african swine fever virus (asfv)-encoded ubiquitin-conjugating enzyme (ubcv1) and used to demonstrate by western blotting (immunoblotting) and immunofluorescence that the enzyme is present in purified extracellular virions, is expressed both early and late after infection of cells with asfv, and is cytoplasmically located. antiubiquitin serum was used to identify novel ubiquitin conjugates present during asfv infections. this antiserum stained virus factories ... | 1995 | 7853518 |
| porcine immune responses to african swine fever virus (asfv) infection. | immune responses mediating protection against asfv are poorly understood. anti-asfv antibodies may influence the course of the clinical disease but they have never been found to neutralize the virus. recent developments on cellular defense mechanisms, using swine protection models, and on the induction and role of some cytokines warrant further investigation on these areas. | 1994 | 7856069 |
| mapping and sequence of the gene encoding protein p17, a major african swine fever virus structural protein. | the gene encoding protein p17, a major structural protein of african swine fever virus, has been mapped and sequenced. protein p17 was purified from dissociated virus by reverse-phase hplc and the amino acid sequence of a peptide obtained after digestion of protein p17 with cyanogen bromide was determined by automated edman degradation. to map the gene encoding protein p17, a mixture of 17-mer oligonucleotides based upon a part of the amino acid sequence was hybridized to cloned african swine fe ... | 1995 | 7856088 |
| replication of transfected plasmid dna by cells infected with african swine fever virus. | recombinant plasmids containing african swine fever virus (asfv) dna fragments covering all the virus genome were transfected into infected cells in order to detect viral origins of dna replication. plasmid replication was monitored by sensitivity to mboi, which cleaves only replicated, unmethylated dna, and resistance to dpni, which cleaves only the same methylated sequence. all the recombinants replicated to a similar extent, indicating that asfv does not use a preferred origin for dna replica ... | 1995 | 7886943 |
| an african swine fever virus gene with similarity to the t-lymphocyte surface antigen cd2 mediates hemadsorption. | an open reading frame, lmw8-dr, in the african swine fever virus (asfv) genome possesses striking similarity to the lymphocyte membrane antigen cd2. all characterized cd2 domains, including the amino-terminal signal sequence, igv, hinge, igc2, stalk, transmembrane, and proline-rich carboxy cytoplasmic domains, are highly conserved in the asfv gene. critical residues for the binding of the lymphocyte function-associated antigen (lfa-3) and cd59 and for t-cell activation are also partially conserv ... | 1994 | 7907198 |
| characterization and molecular basis of heterogeneity of the african swine fever virus envelope protein p54. | it has been reported that the propagation of african swine fever virus (asfv) in cell culture generates viral subpopulations differing in protein p54 (c. alcaraz, a. brun, f. ruiz-gonzalvo, and j. m. escribano, virus res. 23:173-182, 1992). a recombinant bacteriophage expressing a 328-bp fragment of the p54 gene was selected in a lambda phage expression library of asfv genomic fragments by immunoscreening with antibodies against p54 protein. the sequence of this recombinant phage allowed the loc ... | 1994 | 7933107 |
| detection of african swine fever virus protein vp73 in tissues of experimentally and naturally infected pigs. | | 1994 | 7948208 |
| insect iridescent virus type 6 encodes a polypeptide related to the largest subunit of eukaryotic rna polymerase ii. | cytoplasmic dna viruses encode a dna-dependent rna polymerase (ddrp) that is essential for transcription of viral genes. the amino acid sequences of known large subunits of ddrps contain highly conserved regions. oligonucleotide primers, deduced from two conserved domains [rqp(t/s)lh and nadfdgde] were used in pcr experiments for the detection of the corresponding gene of the genome of insect iridescent virus type 6, also known as chilo iridescent virus (civ). a specific dna product of about 150 ... | 1994 | 8021587 |
| nucleotide sequence of a 55 kbp region from the right end of the genome of a pathogenic african swine fever virus isolate (malawi lil20/1). | the nucleotide sequence of a 55098 bp region from the right end of the genome of a virulent african swine fever virus (asfv) isolate (malawi lil20/1) has been determined. translation of the sequence identified 67 major open reading frames (orfs) which are closely spaced and read from both dna strands. at six positions intergenic tandem repeat arrays are found. comparison of the predicted amino acid sequences of encoded proteins with protein sequence databases identified a number of homologies. t ... | 1994 | 8021596 |
| two novel multigene families, 530 and 300, in the terminal variable regions of african swine fever virus genome. | here, we describe two novel multigene families (mgf) present in the terminal variable regions of the african swine fever virus (asfv) genome. mgf530 includes at least six related orfs (averaging 530 amino acids) containing four well-conserved domains and amino acid identities ranging from 24 to 55%. mgf300 is composed of three orfs (averaging 300 amino acids) containing three highly conserved domains and amino acid identities ranging from 25 to 46%. amino terminal regions of predicted mgf530 and ... | 1994 | 8030263 |
| nucleotide sequence of the telomeric region of the african swine fever virus genome. | the 4-kb terminal bcli fragment of african swine fever virus (asfv) dna, including the inverted terminal repetition (itr), was cloned and sequenced. the sequence showed that the 2.1-kb itr is composed of a 301-nucleotide-long unique sequence immediately adjacent to the terminal hairpin loop, a set of 38 tandem direct repeats of a 34-nucleotide degenerate sequence, another unique intervening sequence with no remarkable features, and a set of 5 tandem repeats of a 27-nucleotide unit unrelated in s ... | 1994 | 8030278 |
| swine-reconstituted scid mice as a model for african swine fever virus infection. | injection of swine peripheral blood mononuclear cells into mice with severe combined immunodeficiency (scid), resulted in the stable long-term establishment of a functional swine immune system (scid-sw). swine immunoglobulins were present in the serum of scid-sw mice and swine cells were detected in the blood as well as in lymph nodes and spleen using monoclonal antibodies raised against cell subpopulations. swine lymphocytes from reconstituted scid mice responded in vitro to specific antigens o ... | 1994 | 8046401 |
| attempted transovarial and venereal transmission of african swine fever virus by the iberian soft tick ornithodoros (pavlovskyella) marocanus (acari: ixodoidea: argasidae). | transovarial transmission experiments were conducted with three groups of ornithodoros (pavlovskyella) marocanus velu; one group consisted of 27 pairs of adults that had been fed as larvae on a pig with a viremia of 10(7.4) had50/ml of african swine fever virus (asfv). the second and third groups each consisted of 100 pairs of adults fed on a viremic pig (10(4.5) had50/ml) as adults. the first group underwent five gonotrophic cycles over a 554-d period. the second and third groups underwent thre ... | 1994 | 8057310 |
| [clinical and anatomo-pathological differences in 2 strains of african swine fever virus in angola]. | african swine fever (asf) is prevalent in angola. it is caused by several strains of viruses, among which silva-porto and huambo 85. a clinical and anatomo-pathological comparative test carried out on the natural and experimental disease showed different and significant characteristics in the behaviour of these two strains. silva-porto generates clinical signs characterized by an haemorrhagic generalized diathesis more marked on the skin, organs and viscera. in addition, the anatomo-pathological ... | 1993 | 8073167 |
| chilo iridescent virus encodes a putative helicase belonging to a distinct family within the "dead/h" superfamily: implications for the evolution of large dna viruses. | the complete nucleotide sequence of the ecori dna fragment m (7099 bp; 0.310-0.345 map units) of the genome of insect iridescent virus type 6--chilo iridescent virus (civ)--was determined. a 606 codon open reading frame located in this region encoded a protein (p69) related to a distinct family of putative dna and/or rna helicases belonging to the "dead/h" superfamily. unique sequence signatures were derived that allowed selective retrieval of the putative helicases of the new family from amino ... | 1994 | 8073636 |
| african swine fever virus encodes a cd2 homolog responsible for the adhesion of erythrocytes to infected cells. | we have identified an open reading frame, ep402r, within the ecori e' fragment of the african swine fever virus genome that encodes a polypeptide of 402 amino acid residues homologous to the adhesion receptor of t cells, cd2. transcription of ep402r takes place during the late phase of virus replication. the disruption of ep402r, achieved through the replacement of a 354-bp-long fragment from within ep402r by the marker gene lacz, does not affect the virus growth rate in vitro but abrogates the ... | 1993 | 8102411 |
| analysis of the nucleotide sequence of a 43 kbp segment of the genome of variola virus india-1967 strain. | sequencing and computer analysis of the nucleotide sequence of the variola virus strain india-1967 (var) genome segment (43069 bp) from the region of hindiii c, e, r, q, k, h dna fragments has been carried out. forty-three potential open reading frames (orfs) have been identified, and the polypeptides encoded by them have been compared with the analogous proteins of vaccinia virus strain copenhagen (cop). orf e7r of var is much shorter than the cop analog. the other polypeptides coded by the pot ... | 1993 | 8109158 |
| identification of genes encoding zinc finger proteins, non-histone chromosomal hmg protein homologue, and a putative gtp phosphohydrolase in the genome of chilo iridescent virus. | five rna transcripts of about 1.2 to 1.7 kilobases were mapped to a part of the genome of insect iridescent virus type 6 (chilo iridescent virus; civ) between genome coordinates 0.832 and 0.856 within the ecori dna fragment f. the nucleotide sequence of this particular region (5702 base pairs) of the civ genome was determined. the dna sequence contains a number of perfect direct, inverted, and palindromic repeats including three clusters of tandemly organized repetitive dna elements located betw ... | 1994 | 8121799 |
| genetic identification and nucleotide sequence of the dna polymerase gene of african swine fever virus. | the dna polymerase gene of african swine fever virus (asfv) was mapped by marker rescue experiments using a phosphonoacetic acid-resistant mutant and hybridization with an oligonucleotide probe designed from the most conserved motif of family b dna polymerases. viral dna fragments mapping in this region were cloned and sequenced. an open reading frame coding for a 1244 amino acid long peptide with a molecular mass of 142.5 kda was determined from the sequence. a unique feature of asfv dna polyme ... | 1994 | 8121806 |
| multigene families in african swine fever virus: family 505. | sequencing of restriction fragment ecori a-sali c of african swine fever virus has revealed the existence of a multigene family, designated family 505 because of the average number of amino acids in the proteins, composed of seven homologous and tandemly arranged genes. all the genes of family 505 are expressed during infection. primer extension analysis showed that transcription is initiated a short distance (3 to 62 nucleotides) from the start codon of the corresponding open reading frame. the ... | 1994 | 8139051 |
| epidemiology of classical swine fever in sardinia: a serological survey of wild boar and comparison with african swine fever. | a serological survey was carried out to establish the distribution of classical swine fever among wild boar in sardinia, where that disease and african swine fever have been endemic in free-ranging domestic pigs and wild boar living in the mountainous areas of the province of nuoro for several years. blood samples were collected from 4752 wild boar shot during the period december 1988 to january 1992. an overall prevalence of 11 per cent was observed and the almost constant rate of about 9.8 per ... | 1994 | 8171792 |
| nucleotide sequence and variability of the inverted terminal repetitions of african swine fever virus dna. | african swine fever virus (asfv) genome is a large (170-190 kb) double-stranded dna molecule with structural features similar to those of poxviruses. prominent among those features are the presence of a hairpin loop structure at the end of the dna molecule and terminal-inverted repeats (tir). the tirs have been previously demonstrated by electron microscopy and cross-hybridization of terminal restriction fragments. we have determined the sequence of both left and right dna ends from the ba71v vi ... | 1994 | 8178480 |
| virus-host interactions in african swine fever: the attachment to cellular receptors. | biochemical and morphological techniques have shown that african swine fever virus (asfv) enters susceptible cells by a mechanism of receptor-mediated endocytosis. the virus binds to a specific, saturable site in the cell and this interaction is required for a productive infection. a structural asfv protein of 12kda (p12) has been identified to be involved in the recognition of the cellular receptor, on the basis of the specific binding of the polypeptide to sensitive vero cells. protein p12 is ... | 1993 | 8219802 |
| african swine fever virus genome content and variability. | a 55 kilobase pair (kb) region from the right end of the virulent african swine fever virus isolate, malawi lil20/1, has been sequenced. the 68 major open reading frames (orfs) encoded are generally closely spaced and read from both dna strands across the complete sequence. comparison of the amino acid sequences of predicted orfs with sequence databases identified 15 orfs which encode proteins that are similar to proteins of known function. two orfs are homologous to copies of multigene family 3 ... | 1993 | 8219803 |
| the relative density of cd44-positive porcine monocytic cell populations varies between isolations and upon culture and influences susceptibility to infection by african swine fever virus. | african swine fever (asf) virus has been reported to infect cells of the monocyte family, probably macrophage-like cells, but there is variation in the apparent susceptibility of these cells. we have demonstrated that the phenotype and activity of porcine monocytic cells varies between different isolations and also upon culture. the variation during culture is dependent upon the phenotype of the cells at the time of isolation. as for the susceptibility of porcine monocytes/macrophages to infecti ... | 1993 | 8225410 |
| persistence of african swine fever antibody reactivity on elisa and immunoblotting assays. | | 1993 | 8236717 |
| african swine fever virus interaction with microtubules. | the role of microtubules in intracellular transport of african swine fever virus (asfv) and virus-induced inclusions was studied by immunofluorescence using anti-asfv and anti-tubulin antibodies, by electron microscopy of infected vero cells and by in vitro binding of virions to purified microtubules. mtc, a reversible colchicine analogue, was used to depolymerize microtubules. in cells treated with mtc multiple large inclusions containing asfv antigens and particles were observed in the cytopla ... | 1993 | 8241964 |
| mapping and sequence of the gene encoding the african swine fever virion protein of m(r) 11500. | the gene encoding the african swine fever virus protein of m(r) 11,500, present in the virus particle, has been mapped and sequenced in the genome of the vero cell-adapted virus strain ba71v. a serum raised against virion proteins of m(r) 12,000 to 13,000 isolated from polyacrylamide gels was used to screen a plasmid expression library, containing viral dna random fragments, that expresses viral polypeptides fused to beta-galactosidase. using this method, we have identified and sequenced the ope ... | 1993 | 8245848 |
| long-term persistent infection of swine monocytes/macrophages with african swine fever virus. | long-term persistent infection was established in 100% of pigs (n = 19) experimentally infected with african swine fever virus (asfv). viral dna was detected in peripheral blood mononuclear leukocytes (pbml) at greater than 500 days postinfection by a pcr assay. infectious virus was not, however, isolated from the same pbml samples. in cell fractionation studies of pbml, monocytes/macrophages were found to harbor viral dna during the persistent phase of infection. this result indicates that mono ... | 1994 | 8254776 |
| passively transferred african swine fever virus antibodies protect swine against lethal infection. | the role of anti-viral antibodies in homologous protective immunity to a virulent african swine fever virus (asfv) strain e75 was examined by passive transfer experiments in swine. eighty-five percent of animals (n = 14) that received anti-asfv immunoglobulin (ig) survived challenge infection, while 100% mortality was observed in control group animals (n = 28) that received anti-pseudorabies virus ig, normal swine ig, or phosphate-buffered saline. with the exception of a significantly delayed an ... | 1994 | 8259670 |
| two putative african swine fever virus helicases similar to yeast 'deah' pre-mrna processing proteins and vaccinia virus atpases d11l and d6r. | two open reading frames (orfs) of african swine fever virus (asfv) encoding putative helicases have been sequenced. the two genes, termed d1133l and b962l, are located in the central region of the viral genome, but are separated by about 40 kb of dna. both genes are expressed late during asfv infection of vero cells, after replication of viral dna has begun. contiguous to d1133l, three other orfs (d129l, d79l and d339l), encoding putative proteins of unknown function, have been sequenced. protei ... | 1993 | 8262374 |
| nucleotide sequence of a nucleoside triphosphate phosphohydrolase gene from african swine fever virus. | a putative nucleoside triphosphate phosphohydrolase (ntpase) gene of african swine fever virus was identified by using a degenerate oligonucleotide probe derived from the nucleoside triphosphate binding motif, which is highly conserved among viral and cellular ntpases. the probe hybridized with fragments sali e and ecori q, which is entirely contained in the former one. sequencing of this region revealed an open reading frame, designated q706l, coding for a protein of 706 amino acids, with a cal ... | 1993 | 8266720 |
| characterization of vaccinia virus gene b12r. | we report the characterization of vaccinia virus gene b12r which is predicted to encode a 33k protein with 36% amino acid identity to the serine/threonine protein kinase encoded by vaccinia virus gene b1r. s1 nuclease protection experiments showed that gene b12r is transcribed early during infection from an initiation site 11 bp upstream of the open reading frame (orf). the gene encodes a 33k polypeptide that is not required for virus replication in tissue culture nor for virus virulence in a mu ... | 1993 | 8277291 |
| the dna polymerase-encoding gene of african swine fever virus: sequence and transcriptional analysis. | the putative dna polymerase-encoding gene of african swine fever virus has been sequenced. the gene, designated g1207r, is located in the central region of the viral genome, and encodes a protein of 1207 amino acids (aa) with a predicted m(r) of 139,835. the gene is transcribed at both early and late stages of infection into a 4.1-kb rna. transcription is initiated at tsp, 8 nucleotides (nt) upstream from the start codon. open reading frame (orf) g1207r contains four direct repeats in tandem clo ... | 1993 | 8293992 |
| [lipids from the african swine fever virus]. | the lipids of highly purified african swine fever virus (asfv) propagated in porcine bone marrow cells were observed to contain 25.6% phospholipids, 9.7% monoglycerides, 14.1% cholesterol, 17.8% free fatty acids, 14.4% diglycerides, 13.6% triglycerides, and 6.7% cholesterol ethers. diethyl ether extracts mono-, di-, triglycerides, free fatty acids, 50% of cholesterol and cholesterol ethers, and 25% of phospholipids from the virus. analysis of the 14c-sodiumacetate incorporation into viral, cellu ... | 1993 | 8302309 |
| african swine fever virus encodes a serine protein kinase which is packaged into virions. | nucleotide sequencing of the sali j region of the virulent malawi (lil20/1) strain of african swine fever virus (asfv) identified an open reading frame (orf), designated j9l, with extensive similarity to the family of protein kinases. this orf encodes a 35.1-kda protein of 299 amino acids which shares 24.6% amino acid identity with the human pim-1 proto-oncogene and 21.0% identity with the vaccinia virus b1r-encoded protein kinase. the asfv orf contains the motifs characteristic of serine-threon ... | 1993 | 8331722 |
| an african swine fever virus gene with a similarity to eukaryotic rna polymerase subunit 6. | | 1993 | 8332503 |
| polyprotein processing in african swine fever virus: a novel gene expression strategy for a dna virus. | this report shows that african swine fever virus (asfv)--a large dna-containing virus--synthesizes a polyprotein to produce several of its structural proteins. by immunoprecipitation analysis, we have found that asfv polyprotein is a 220 kda myristoylated polypeptide (pp220) which, after proteolytic processing, gives rise to four major structural proteins: p150, p37, p34 and p14. processing of the asfv polyprotein takes place at the consensus sequence gly-gly-x and occurs through an ordered casc ... | 1993 | 8335009 |
| inhibition of african swine fever virus binding and infectivity by purified recombinant virus attachment protein p12. | the african swine fever virus protein p12, involved in virus attachment to the host cell, has an apparent molecular mass of 17 kda in sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions. we have also identified 12- and 10-kda forms of the p12 protein in infected vero cells and found that the mature 17-kda protein is the only form present in virus particles. the p12 protein has been produced in large amounts in spodoptera frugiperda insect cells infected with a ... | 1993 | 8350406 |
| characterization of a soluble hemagglutinin induced in african swine fever virus-infected cells. | hemadsorption (had) of erythrocytes to the surface of african swine fever virus (asfv)-infected cells is a well-known phenomenon but hemagglutination of pig erythrocytes in the supernatant of asfv-infected cells has not been reported before. we report here the discovery of a pig erythrocyte-agglutinating activity released to the in vitro cell culture medium by cells infected with some isolates of asfv. this finding allowed the identification and characterization of a soluble hemagglutinin (ha) m ... | 1993 | 8372447 |
| three african swine fever virus genes encoding proteins with homology to putative helicases of vaccinia virus. | sequence analysis of the sali g, h, i and j restriction fragments of the african swine fever virus (asfv) genome from the virulent isolate malawi (lil20/1) identified three open reading frames (orfs) encoding predicted proteins of 125.0k (g10l), 80.4k (j10l) and 58.0k (j11l) which showed homology to members of the dna and rna helicase superfamily. orfj10l was related to protein 4 of the kluyveromyces lactis killer plasmid pkg12 and to two putative helicases, d6r and d11l, of vaccinia virus. orf ... | 1993 | 8376971 |
| african swine fever virus guanylyltransferase. | the gene coding for the guanylyltransferase of african swine fever virus has been identified and sequenced. the gene, designated np868r, is located within fragments ecori n' and d of the virus genome (ba71v strain) and encodes a protein with a predicted molecular mass of 99.9 kda that shares significant similarity with the large subunit of both vaccinia and shope fibroma virus capping enzymes, with percentages of identity of 20.6 and 21.8%, respectively. a protein of 95 kda was induced in escher ... | 1993 | 8382399 |
| the identification of an african swine fever gene with conserved helicase motifs and a striking homology to herpes virus origin binding protein, ul9. | | 1993 | 8389041 |
| an african swine fever virus gene with similarity to the proto-oncogene bcl-2 and the epstein-barr virus gene bhrf1. | an open reading frame, lmw5-hl, in the african swine fever virus genome displays a high degree of similarity to the proto-oncogene bcl-2 and, to a lesser degree, the epstein-barr virus gene bhrf1. a highly conserved central region is found in all three proteins. lmw5-hl encodes a protein of 18 kda that is present in infected porcine macrophages at both early and late times postinfection. the similarity of lmw5-hl to bcl-2 and bhrf1 suggests a role for it in cell maintenance during productive or ... | 1993 | 8389936 |
| african swine fever virus thymidylate kinase gene: sequence and transcriptional mapping. | a putative thymidylate kinase gene of african swine fever virus has been identified at the left end of the sali i' fragment of the virus genome. the gene, designated a240l, has the potential to encode a protein of 240 amino acids with an m(r) of 27,754 and is transcribed early after infection. primer extension analysis indicates that transcription is initiated a short distance from the first atg codon of open reading frame a240l. the deduced amino acid sequence of this open reading frame shows s ... | 1993 | 8393914 |
| three adjacent genes of african swine fever virus with similarity to essential poxvirus genes. | nucleotide sequencing of the right end of the salij fragment of the highly virulent malawi lil20/1 strain of african swine fever virus (asfv) has revealed three adjacent genes with similarity to: serine-threonine protein kinases; members of the putative helicase superfamily sf2; and the vaccinia virus 56 kda abortive late protein. all three genes are transcribed to the left with respect to the orientation of the asfv genome. gene l19il predicts a protein similar to serine-threonine protein kinas ... | 1993 | 8397501 |
| duplicated genes within the variable right end of the genome of a pathogenic isolate of african swine fever virus. | the right variable region of the genome of a pathogenic strain of african swine fever virus (asfv), malawi lil20/1, has been sequenced and 15 open reading frames (orfs) identified by computer analysis. eight of these orfs were found to be similar to previously described asfv orfs and three of these belong to two previously described multiple gene families (mgf), 360 and 110. four of the remaining five orfs belong to a novel mgf, designated mgf 100, and the last orf encodes a protein that is simi ... | 1993 | 8409937 |
| identification of the gene encoding the major capsid protein of fish lymphocystis disease virus. | the gene encoding the major capsid protein (mcp) of fish lymphocystis disease virus (flounder isolate; flcdv-f) has been identified by pcr using oligonucleotide primers corresponding to different regions of the mcp of tipula iridescent virus (tiv), iridescent virus 22 (iv22) and chilo iridescent virus (civ). dna fragments of 0.4 kbp, 0.5 kbp and 0.27 kbp in size were amplified using oligonucleotide primers corresponding to amino acids (aa) 146 to 153 (primer 1) and 274 to 268 (primer 6), or aa 1 ... | 1993 | 8409939 |
| transcriptional mapping of a late gene coding for the p12 attachment protein of african swine fever virus. | the transcriptional characterization of the gene coding for the p12 attachment protein of the african swine fever virus is presented. the results obtained have been used to generate the first detailed transcriptional map of an african swine fever virus late gene. novel experimental evidence indicating the existence of major differences between the mechanisms controlling the transcription of late genes in african swine fever virus and poxviruses is provided. | 1993 | 8416381 |
| high-level expression in escherichia coli of the gene coding for the major structural protein (p72) of african swine fever virus. | the gene encoding the major structural protein (p72) of african swine fever virus (asfv) has been expressed in escherichia coli using a t7 rna polymerase system. the use of a recombinant plasmid which contains the entire gene inserted between the t7 promoter and the transcription terminator of the expression vector allowed us to obtain a high expression level of the intact viral protein. this polypeptide, which appears in the insoluble fraction of the bacterial extracts, showed an intense reacti ... | 1993 | 8428668 |
| african swine fever virus encodes a dna ligase. | sequencing of the ecori n' fragment of african swine fever virus (asfv) dna revealed an open reading frame encoding a protein similar to atp-dependent dna ligases. when the gene encoding this protein was expressed in escherichia coli, a protein of the expected molecular mass was labeled in bacterial extracts upon incubation with [alpha-32p]atp. the recombinant protein comigrated in sds-page with the putative viral dna ligase detected in extracts of infected cells. we demonstrate that the recombi ... | 1993 | 8438592 |
| activity of several s-adenosylhomocysteine hydrolase inhibitors against african swine fever virus replication in vero cells. | several inhibitors of s-adenosylhomocysteine (adohcy) hydrolase have been found to selectively suppress the replication of african swine fever virus (asfv) in vero cells. of the compounds tested, 3-deazaneplanocin a proved to be the most potent and selective inhibitor of asfv replication. its selectivity index (si) was 3000. then followed 9-(trans-2',trans-3'-dihydroxycyclopentyl)-3- deazaadenine (si = 2500), the 4'beta-vinyl derivative of 9-(trans-2',trans-3'-dihydroxycyclopentyl)adenine (si = ... | 1993 | 8460931 |
| an african swine fever virus gene with similarity to bacterial dna binding proteins, bacterial integration host factors, and the bacillus phage spo1 transcription factor, tf1. | | 1993 | 8464748 |
| african swine fever virus specific porcine cytotoxic t cell activity. | african swine fever virus (asfv) specific, cytotoxic t lymphocyte (ctl) activity has been studied in a protection model in which sla inbred miniature swine are experimentally inoculated with a naturally occurring, non-fatal asfv isolate (nhv). peripheral blood mononuclear cells (pbmc) from such infected swine show significant activity in ctl assays, using cultured asfv-infected porcine blood derived macrophages as target cells. this ctl activity is elicited from pbmc by in vitro restimulation of ... | 1993 | 8470951 |
| sequence and characterization of the major early phosphoprotein p32 of african swine fever virus. | the gene encoding protein p32, the most abundant and immunogenic protein induced by african swine fever virus at early times of infection, has been mapped in the ecori c' fragment of the genome of the vero cell-adapted virus strain ba71v. sequencing analysis has shown the existence of an open reading frame, named c'204l, encoding 204 amino acids. the protein is phosphorylated in serine residues located in the 115 n-terminal amino acids and was phosphorylated when expressed in cells infected with ... | 1993 | 8474154 |