| a bir motif containing gene of african swine fever virus, 4cl, is nonessential for growth in vitro and viral virulence. | an african swine fever virus (asfv) gene with similarity to viral and cellular inhibitor of apoptosis genes (iap) has been described in the african isolate malawi lil-20/1 (orf 4cl) and a cell-culture-adapted european virus, ba71v (orf a224l). the similarity of the asfv gene to genes involved in inhibiting cellular apoptosis suggested the gene may regulate apoptosis in asfv-infected cells and thus may function in asfv virulence and/or host range. sequence analysis of additional african and europ ... | 1997 | 9143281 |
| [swine plague: symptoms, epizootiology and diagnosis]. | the clinical signs, laboratory diagnosis and modes of transmission of classical swine fever are described. special attention is paid to combinations of signs of disease which should arise suspicion to the veterinary practitioner in the present epizootic. | 1997 | 9157622 |
| influence of breed-related factors on the course of classical swine fever virus infection. | | 1997 | 9172299 |
| development of microscopic lesions in splenic cords of pigs infected with african swine fever virus. | acute forms of african swine fever are characterized by hemorrhagic lesions in the lymphoid organs. this paper reports the evolution of lesions in the splenic cords of pigs inoculated with african swine fever (asf) virus (strain malawi'83). ultrastructural examination of the splenic cords of the infected pigs revealed numerous macrophages attached to the muscle cells harboring virus replication center and cytopathic effects at 3 dpi (days post-infection). from 5 dpi, the splenic cords contained ... | 1997 | 9172845 |
| molecular characterization of hog cholera virus. | an efficient tissue culture system was established which allowed to obtain substantial quantities of hog cholera virus (hcv) from the cell free tissue culture supernatant. after preparation of viral rna and cdna synthesis, the complete hcv genome was cloned and sequenced. comparison with published bvdv sequences revealed a surprisingly high homology between hcv and bvdv at both the nucleotide and the amino acid level. in addition host cellular sequences were identified in bvdv genomes. the genom ... | 1991 | 9210921 |
| cdna probes for the detection of pestiviruses. | probes were prepared from genomic rna of hog cholera virus (hcv) after synthesis of cdna and cloning. six probes were selected according to their place on the viral genome determined by sequencing and comparison with bvdv sequence. these probes were hybridized with two strains of hcv (alfort and nord), two strains of bovine viral diarrhea (bvdv) (nadl, new york) and four strains of border disease (bd) (lyon 1, lyon 2, aveyron, iemvt). this panel of six probes seem to be able to differentiate pes ... | 1991 | 9210941 |
| differentiation of pestiviruses by a hog cholera virus-specific genetic probe. | a hog cholera virus (hcv)-specific genetic probe has been generated after cloning of the genomic viral rna. this probe distinguished between hcv and the closely related bovine viral diarrhoea virus (bvdv). furthermore, it detected a broad spectrum of hcv strains and isolates which differ in their phenotype such as virulence. | 1991 | 9210943 |
| polymerase chain reaction amplification of segments of pestivirus genomes. | reverse transcription followed by polymerase chain reaction (pcr) amplification of a region of the viral genome at the 3' end of the glycoprotein(s) gene was employed with the aim of determining its applicability as a diagnostic tool for pestiviruses. candidate primers were designed, from homologous segments detected by comparison between the sequences of strains nadl, osloss and alfort. a segment of 634 base pairs on the glycoprotein gene was targeted for amplification. segments of five pestivi ... | 1991 | 9210946 |
| blocking antibodies inhibit complete african swine fever virus neutralization. | a persistent non-neutralized african swine fever virus (asfv) fraction is found with most convalescent swine sera in in vitro neutralization assays. to study this phenomenon, antisera from convalescent pigs infected with different virus isolates and showing complete or incomplete virus neutralization were used. different experiments determined that incomplete neutralization of asfv is caused neither by virus aggregation, nor low affinity or stability of virus-antibody complexes. additionally, at ... | 1997 | 9213385 |
| african swine fever virus-specific cytotoxic t lymphocytes recognize the 32 kda immediate early protein (vp32). | african swine fever (asf) virus-specific cytotoxic t lymphocyte (ctl) activity has been studied in a model in which sla inbred minipigs were experimentally infected with an attenuated isolate of the virus. the ctl assays were performed using alveolar macrophages as target cells. the specific lysis is mediated by purified cd8+ lymphocytes but not by cd4+ cells and can be blocked by incubation with anti-sla class i monoclonal antibodies. the purified cd8+ population produced high levels of interfe ... | 1997 | 9213386 |
| protein cell receptors mediate the saturable interaction of african swine fever virus attachment protein p12 with the surface of permissive cells. | previous studies have demonstrated that the entry of african swine fever virus (asfv) into vero cells and swine macrophages is mediated by saturable binding sites located on the plasma membrane. the asfv protein p12 has been implicated in virus attachment to the host cell, but the cellular component responsible for the interaction with the virus is largely unknown. we have studied the binding of recombinant p12 and asfv to different cell lines. permissive cells were able to bind p12 in saturable ... | 1997 | 9213394 |
| proteolytic processing in african swine fever virus: evidence for a new structural polyprotein, pp62. | we have identified an open reading frame (orf), cp530r, within the ecori c' fragment of the african swine fever virus (asfv) genome that encodes a polyprotein of 62 kda (pp62). antisera raised against different regions of orf cp530r recognized a polypeptide of 62 kda in asfv-infected cells during the late phase of virus replication, after the onset of viral dna synthesis. pulse-chase experiments showed that polyprotein pp62 is posttranslationally processed to give rise to two proteins of 35 kda ... | 1997 | 9223468 |
| [bovine diarrhea virus: an update]. | bovine viral diarrhea virus (bvdv) is a pathogen of cattle, member of the family flaviviridae, genus pestivirus, which also includes classical swine fever virus (csfv, or hog cholera virus), and border disease virus of sheep (bdv). it causes important economical losses associated mainly with reproductive failure. pestiviruses are small enveloped viruses, with a diameter of about 40 nm. the nucleocapsid is probably icosahedral . the genome consists of a single stranded positive rna, encoding appr ... | 1997 | 9229725 |
| a solid-phase enzyme linked immunosorbent assay using monoclonal antibodies, for the detection of african swine fever virus antigens and antibodies. | an improved solid-phase enzyme linked immunosorbent assay (elisa) using monoclonal antibodies was developed to detect an african swine fever virus protein (vp73) in pig samples. the use of monoclonal antibodies against vp73 allowed a sensitive and specific sandwich elisa. this assay detected a limiting antigen concentration of 0.05 microgram/ml of vp73, lower than the detection limit of 0.6 microgram/ml obtained by using polyclonal antibodies by the same elisa. the whole virus particle was detec ... | 1997 | 9255732 |
| characterization of five monoclonal antibodies specific for swine class ii major histocompatibility antigens and crossreactivity studies with leukocytes of domestic animals. | a set of five monoclonal antibodies (mab) against porcine major histocompatibility complex (mhc), or swine leukocyte antigens (sla), class ii molecules has been characterized. these mabs appear to recognize monomorphic determinants on sla-dr (2f4, 1f12 and 2e9/13) and sla-dq (bl2h5 and bl4h2) molecules, as assessed by flow cytometry and immunoprecipitation. by western blot, the 2f4, 1f12, bl2h5 and bl4h2 epitopes were located on the beta-chains of these molecules. mabs 2f4 and 1f12 crossreact wi ... | 1997 | 9258612 |
| glycoprotein erns of pestiviruses induces apoptosis in lymphocytes of several species. | classical swine fever virus and bovine virus diarrhea virus are members of the genus pestivirus, which belongs to the family of the flaviviridae. recently, envelope glycoprotein erns was identified as an rnase. rnases can express different biological actions. they have been shown to be neurotoxic, antihelminthic, and immunosuppressive. we studied the immunosuppressive properties of erns in vitro. the glycoprotein totally inhibited concanavalin a-induced proliferation of porcine, bovine, ovine, a ... | 1997 | 9261392 |
| a conserved african swine fever virus ikappab homolog, 5el, is nonessential for growth in vitro and virulence in domestic swine. | an african swine fever virus (asfv) gene with similarity to the cellular inhibitor of nfkappab (ikappab) was described in the pathogenic african isolate malawi lil-20/1 (orf 5el) and a cell-culture-adapted european virus, ba71v (orf a238l). recently, this gene was shown to be a functional ikappab homolog capable of downregulating nfkappab-regulated gene expression. this observation suggests the gene may be of significance to aspects of asfv pathogenesis and virulence in domestic swine by interfe ... | 1997 | 9281518 |
| comparison of the complete genomic sequence of the border disease virus, bd31, to other pestiviruses. | the genus pestivirus is composed of hog cholera virus (hcv) [also known as classical swine fever virus (csfv)], bovine viral diarrhea virus (bvdv), and border disease virus (bdv). complete sequences have been published for hcv (or csfv) and the two genotypes of bvdv (bvdv1 and bvdv2). in this study the complete sequence of the border disease virus (bdv), bd31, was determined. bd31 was isolated from a lamb with hairy shaker syndrome and is the bdv type virus offered by atcc (atcc vr-996). the gen ... | 1997 | 9282788 |
| [activation of proteinases and acid phosphatase in swine leukocytes infected with the swine classical plague virus]. | the activities of proteinases active at neutral ph and of acid phosphatase increases after freezing and defrosting and hypotonic shock in porcine leukocytes in vitro infected with the classical hog cholera virus in comparison with intact cells. the enzymes in the cells from animals both immune and nonimmune to hog cholera were activated upon infection with both virulent and vaccine strains of the virus. no proteinase activity was detected in the culture medium in which infected porcine leukocyte ... | 1997 | 9297106 |
| [a comparative phylogenetic analysis of the coding portion of the genes for structural protein e1 in the shi-min' strain and in other strains of the classic hog cholera virus]. | the primary nucleotide sequence of the fragment of e1 (gp51-55) gene (772 bp in length) of virulent strain shi-min' of classical swine fever virus (csfv) has been determined. multiple alignments of the e1 gene fragments of various strains and isolates of csfv, which are homologues to the cloned fragment, has been carried out; the phylogenetic tree has been plotted and the consensus sequence has been determined. the strain shi-min', which was used as a control csfv strain in former soviet republi ... | 1997 | 9297292 |
| changes in swine macrophage phenotype after infection with african swine fever virus: cytokine production and responsiveness to interferon-gamma and lipopolysaccharide. | cytokines produced by cells of the immune system, including macrophages, can influence inflammatory responses to viral infection. this has been exploited by viruses, which have developed strategies to direct the immune response towards ineffective responses. african swine fever virus (asfv) is a double-stranded dna virus that infects macrophages of domestic swine. in this study, primary cells of monocyte macrophage lineage were obtained from the lungs, peritoneum or blood of domestic swine and, ... | 1997 | 9301535 |
| likelihood of introducing selected exotic diseases to domestic swine in the continental united states of america through uncooked swill. | to help policy makers determine the need for current regulations (which require cooking of swill prior to feeding to swine), an assessment of the likelihood of exposing domestic swine in the continental united states of america (usa) to selected foreign animal disease agents by feeding uncooked swill was carried out. the hazard was assumed to originate from contraband food items entering the usa and subsequently being discarded in household waste. such food waste may be collected by licensed was ... | 1997 | 9329117 |
| antiviral activity of an extract from leaves of the tropical plant acanthospermum hispidum. | incubation of the alphaherpesviruses pseudorabiesvirus (prv) and bovine herpesvirus 1 during infection of cell cultures with an extract prepared from the leaves of acanthospermum hispidum impaired productive replication of these viruses in a concentration-dependent manner whereas propagation of classical swine fever virus, foot-and-mouth disease virus and vaccinia virus was not affected. the 50% inhibitory concentration for cell growth (ic50) was 107 +/- 5 microliters/ml, and the concentration r ... | 1997 | 9330761 |
| [quality management in the serodiagnosis of european swine fever: results of comparative tests]. | in the course of inter-laboratory quality management comparative serological tests on classical swine fever (csf) are conducted once per year. results from tests carried out in 1994 and 1995 indicate that most regional diagnostic laboratories were able to classify the test sera correctly as csf-positive, bovine viral diarrhea (bvd)-positive and negative, respectively. difficulties were encountered in the differential diagnosis of csf and bvd in neutralisation tests. there is a need to improve th ... | 1997 | 9340262 |
| subdivision of the pestivirus genus based on envelope glycoprotein e2. | conventionally, the genus pestivirus of the family flaviviridae has been divided into bovine viral diarrhea virus (bvdv), classical swine fever virus (csfv), and border disease virus (bdv). to date, bdv and bvdv have been isolated from different species, whereas csfv seems to be restricted to swine. pestiviruses are structurally and antigenically closely related. envelope glycoprotein e2 is the most immunogenic and most variable protein of pestiviruses. we cloned e2 genes of many different pesti ... | 1997 | 9356345 |
| double-labelling immunohistochemical study of megakaryocytes in african swine fever. | bone marrow samples from pigs infected with the highly virulent malawi'83 or moderately virulent dominican republic (dr'78) isolates of african swine fever virus were studied by means of a double labelling immunohistochemical technique which stained the major structural protein vp73 of the virus and megakaryocytes simultaneously. in pigs infected with the highly virulent malawi'83 isolate, 2.2 per cent of megakaryocytes were vp73+ five days after inoculation, and at six and seven days 2.5 and 9. ... | 1997 | 9364707 |
| inhibition of pestivirus infection in cell culture by envelope proteins e(rns) and e2 of classical swine fever virus: e(rns) and e2 interact with different receptors. | pure preparations of envelope glycoproteins e(rns) and e2 of classical swine fever virus (csfv) synthesized in insect cells were used to study infection of porcine and bovine cells with the pestiviruses csfv and bovine viral diarrhoea virus (bvdv). almost 100% inhibition of infection of porcine kidney cells with csfv was produced by 100 microg/ml e(rns). after removal of the virus no e(rns) was needed in the overlay medium (growth medium) to maintain this level of inhibition. in contrast, 100% i ... | 1997 | 9367363 |
| structure-function analysis of the triphosphatase component of vaccinia virus mrna capping enzyme. | the n-terminal 60 kda (amino acids 1 to 545) of the d1 subunit of vaccinia virus mrna capping enzyme is an autonomous bifunctional domain with triphosphatase and guanylyltransferase activities. we previously described two alanine cluster mutations, r77 to a (r77a)-k79a and e192a-e194a, which selectively inactivated the triphosphatase component. here, we characterize the activities of 11 single alanine mutants-e37a, e39a, q60a, e61a, t67a, t69a, k75a, r77a, k79a, e192a, and e194a-and a quadruple ... | 1997 | 9371657 |
| characterization of an african swine fever virus 20-kda dna polymerase involved in dna repair. | african swine fever virus (asfv) encodes a novel dna polymerase, constituted of only 174 amino acids, belonging to the polymerase (pol) x family of dna polymerases. biochemical analyses of the purified enzyme indicate that asfv pol x is a monomeric dna-directed dna polymerase, highly distributive, lacking a proofreading 3'-5'-exonuclease, and with a poor discrimination against dideoxynucleotides. a multiple alignment of family x dna polymerases, together with the extrapolation to the crystal str ... | 1997 | 9388236 |
| biologically safe, non-transmissible pseudorabies virus vector vaccine protects pigs against both aujeszky's disease and classical swine fever. | envelope glycoprotein d (gd) of pseudorabies virus (prv) is essential for penetration but is not required for cell-to-cell spread. when animals are inoculated with a phenotypically complemented prv gd mutant, the virus is able to spread locally by means of direct cell-to-cell transmission, but progeny virions released by infected cells are non-infectious because they lack gd. therefore, the virus cannot be transmitted from inoculated animals to other animals. this property makes a prv gd mutant ... | 1997 | 9400982 |
| detection of virus or virus specific nucleic acid in foodstuff or bioproducts--hazards and risk assessment. | there are two possibilities for virus contamination of foodstuff and bioproducts of animal origin: i) the presence of endogenous virus as a result of an acute or subclinical infection of animal raw material used for food processing or ii) contamination of food in the course of processing or thereafter. the latter must be considered as the highest risk for human consumers since the viral contamination mostly is caused by virus shedding people and the transmitted viruses are obligate human pathoge ... | 1997 | 9413526 |
| inactivation of the rnase activity of glycoprotein e(rns) of classical swine fever virus results in a cytopathogenic virus. | envelope glycoprotein e(rns) of classical swine fever virus (csfv) has been shown to contain rnase activity and is involved in virus infection. two short regions of amino acids in the sequence of e(rns) are responsible for rnase activity. in both regions, histidine residues appear to be essential for catalysis. they were replaced by lysine residues to inactivate the rnase activity. the mutated sequence of e(rns) was inserted into the p10 locus of a baculovirus vector and expressed in insect cell ... | 1998 | 9420210 |
| a prokaryotic-like mode of cytoplasmic eukaryotic ribosome binding to the initiation codon during internal translation initiation of hepatitis c and classical swine fever virus rnas. | initiation of translation of hepatitis c virus and classical swine fever virus mrnas results from internal ribosomal entry. we reconstituted internal ribosomal entry in vitro from purified translation components and monitored assembly of 48s ribosomal preinitiation complexes by toe-printing. ribosomal subunits (40s) formed stable binary complexes on both mrnas. the complex structure of these rnas determined the correct positioning of the initiation codon in the ribosomal "p" site in binary compl ... | 1998 | 9420332 |
| organization and diversity of the 3'-noncoding region of classical swine fever virus genome. | specific pcr primers were selected to amplify a 359 bp dna fragment flanking the 3'-part of the polymerase gene and the 3'-noncoding (3'-nc) region of the genome of classical swine fever virus (csfv). in rt-pcr the selected fragment was amplified from the genomes of 27 viral strains collected from europe, america and asia over a period of a half century as well as from three vaccine strains of csfv. eight pcr products were sequenced using an automatic sequencing device. nucleotide sequence analy ... | 1997 | 9421882 |
| [development of technology for culturing classical swine fever virus in cultured animal cells]. | the sensitivities of ten continuous cell strains to three hcv strains (shi-min, lk-vniivvim. and lk-k) are assessed. the virus has been cultured by different methods: stationary, roller, suspension culturing, and using deae-2.5 microcarrier. the infective activity of the virus cultured by different methods in different cultures varied from 5.0 to 7.5 lg ccid50/ml. | 1997 | 9424851 |
| effect of husbandry methods on seropositivity to african swine fever virus in sardinian swine herds. | multiple logistic regression was used on serological data collected in the context of the sardinian african swine fever (asf) eradication program from pig farms in the province of nuoro, sardinia. the monthly percentage of asfv-positive herds decreased significantly from october 1994 through march 1996 (p < 0.001). the farm-level risk of seropositivity to african swine fever virus (asfv) was higher in free-range farms than in partial-confinement farms (odds ratios (or) varied between 4.9 in octo ... | 1997 | 9443330 |
| a nonessential african swine fever virus gene uk is a significant virulence determinant in domestic swine. | sequence analysis of the right variable genomic region of the pathogenic african swine fever virus (asfv) isolate e70 revealed a novel gene, uk, that is immediately upstream from the previously described asfv virulence-associated gene nl-s (l. zsak, z. lu, g. f. kutish, j. g. neilan, and d. l. rock, j. virol. 70:8865-8871, 1996). uk, transcriptionally oriented toward the right end of the genome, predicts a protein of 96 amino acids with a molecular mass of 10.7 kda. searches of genetic databases ... | 1998 | 9444996 |
| the evolution of virus-induced apoptosis. | viruses from several different families are able to exploit their host's cell death programmes so as to maximize viral fitness. consideration of the evolution of such strategies has lead to the suggestion that the virus should inhibit apoptosis, in order to prolong the life of the cell and thereby maximize the number of progeny virions. the host, on the other hand, should stimulate apoptosis thereby inhibiting viral growth and blocking viral spread. for example, the function of the latent membra ... | 1997 | 9447732 |
| an improved elisa for the detection of serum antibodies directed against classical swine fever virus. | the complex-trapping-blocking (ctb) elisa for detection of antibodies against classical swine fever virus (csfv) using two monoclonal antibodies (mabs) directed against envelope glycoprotein e2, has been improved using recombinant csfv e2-antigen. the newly developed ceditest elisa for csfv-ab is a modification of the ctb-elisa as described by wensvoort et al. (1988) and bloemraad et al. (1993). the old ctb-elisa format comprised of a two-step, single-dilution test which had to be performed by h ... | 1997 | 9460193 |
| infection with classical swine fever virus: effects on phenotype and immune responsiveness of porcine t lymphocytes. | t lymphocytes obtained from pigs infected with a lethal dose of classical swine fever virus were analysed for phenotypic changes in the composition of t-cell subpopulations and for alterations in their immune responsiveness in vitro during the course of disease. viral antigen detected in all subpopulations and the selective depletion of cd4- cd8- gamma/delta t cells showed that peripheral blood t lymphocytes were affected in the terminal stage (14-19 days post-infection) of classical swine fever ... | 1998 | 9460919 |
| characterization of a bovine viral diarrhea virus isolated from roe deer in germany. | the 5' untranslated region (5' utr) of cytopathogenic pestiviruses isolated from two seronegative roe deer (capreolus capreolus) in northern germany was partially sequenced and compared with those of 28 other pestiviruses. due to the occurrence within a narrow location and the complete identity of the sequenced fragments from both roe deer isolates (sh9 and sh11) they seem to belong to the same bovine virus diarrhea virus (bvdv) strain called sh9/11. this strain is highly homologous (up to 93% i ... | 1998 | 9476225 |
| inhibition of nuclear factor kappab activation by a virus-encoded ikappab-like protein. | certain viruses have evolved mechanisms to counteract innate immunity, a host response in which nuclear factor kappab (nf-kappab) transcription factors play a central role. african swine fever virus encodes a protein of 28.2 kda containing ankyrin repeats similar to those of cellular ikappab proteins, which are inhibitors of nf-kappab. transfection of the african swine fever virus ikappab gene inhibited tumor necrosis factor- or phorbol ester-induced activation of kappab- but not ap-1-driven rep ... | 1998 | 9479002 |
| sequence and organization of the left multigene family 110 region of the vero-adapted l60v strain of african swine fever virus. | sequencing of the left variable region of the l60v vero cell-adapted strain of african swine fever virus (asfv) showed the presence of three genes belonging to multigene family 110 (mgf110) and of a fourth unrelated gene. this gene was separated from the mgf110 genes by a region rich in direct repeats. the first mgf110 gene, v1l, with 104 codons, was only moderately related to the other two, w1l and w2l, with 124 and 80 codons, respectively. these two genes were closely related, w2l being a trun ... | 1997 | 9482593 |
| genetic heterogeneity of classical swine fever virus in central europe. | the aim of this work was to genetically characterize central european isolates of classical swine fever virus (csfv) and to evaluate the applicability of molecular analysis in the epizootiology of csfv infections. thirty four viruses, derived from central european pigs or wild boar, were examined. all of these viruses were detected by each of three sets of oligonucleotide primers which had been designed for the specific rt-pcr amplification of different genomic regions. comparative sequence anal ... | 1997 | 9495535 |
| generation of cytopathogenic subgenomic rna of classical swine fever virus in persistently infected porcine cell lines. | two biological clones (a.1 and b.2) of the classical swine fever virus strain alfort/187 and the recombinant virus va187-1, derived from a cdna clone of alfort/187, were used to establish persistently infected cultures of the swine kidney cell lines sk-6 and pk-41. it was found that 100% of the cells in the passaged cultures were positive for viral antigen throughout the course of the experiment. additionally, supernatants collected upon passaging of the cells continuously contained high titers ... | 1997 | 9498611 |
| african swine fever virus infection in the argasid host, ornithodoros porcinus porcinus. | the pathogenesis of african swine fever virus (asfv) infection in ornithodoros porcinus porcinus was examined in nymphal ticks infected with the asfv isolate chiredzi/83/1. at times postinfection (p.i.) ranging from 6 h to 290 days, ticks or dissected tick tissues were titrated for virus and examined ultrastructurally for evidence of virus replication. the asfv infection rate in ticks was 100% in these experiments, and virus infection was not associated with a significant increase in tick mortal ... | 1998 | 9499019 |
| lymphocyte apoptosis during classical swine fever: implication of activation-induced cell death. | infection of pigs with classical swine fever virus (csfv), a member of the flaviviridae family, causes a severe leukopenia, particularly notable with the lymphocytes. the goal of this study was to analyze mechanisms behind this csfv-induced lymphopenia. to this end, the kinetics of leukocyte depletion, the appearance of apoptotic cells, and virus infection of leukocytes after infection of pigs with the virulent csfv strain brescia were analyzed. depletion of b and t lymphocytes was noted as earl ... | 1998 | 9499036 |
| a retention signal necessary and sufficient for endoplasmic reticulum localization maps to the transmembrane domain of hepatitis c virus glycoprotein e2. | the hepatitis c virus (hcv) genome encodes two envelope glycoproteins (e1 and e2). these glycoproteins interact to formin a noncovalent heterodimeric complex which is retained in the endoplasmic reticulum (er). to identify whether e1 and/or e2 contains an er-targeting signal potentially involved in er retention of the e1-e2 complex, these proteins were expressed alone and their intracellular localization was studied. due to misfolding of e1 in the absence of e2, no conclusion on the localization ... | 1998 | 9499075 |
| african swine fever virus is wrapped by the endoplasmic reticulum. | african swine fever (asf) virus is a large dna virus that shares the striking icosahedral symmetry of iridoviruses and the genomic organization of poxviruses. both groups of viruses have a complex envelope structure. in this study, the mechanism of formation of the inner envelope of asf virus was investigated. examination of thin cryosections by electron microscopy showed two internal membranes in mature intracellular virions and all structural intermediates. these membranes were in continuity w ... | 1998 | 9499098 |
| thrombocytopenia associated with apoptotic megakaryocytes in a viral haemorrhagic syndrome induced by a moderately virulent strain of african swine fever virus. | a viral haemorrhagic syndrome was induced in 14 pigs by inoculation with an african swine fever (asf) virus strain of moderate virulence, to determine changes in megakaryocyte (mk) numbers and morphology and thus to assess the role of these cells in the thrombocytopenia characteristic of subacute asf. the strain tested induced changes in the proportion of different types of mk (typical nucleated mks, apoptotic mks and immature mks); it also caused subcellular lesions over the first 7 days post-i ... | 1998 | 9500234 |
| the public health risks associated with wild and feral swine. | wild swine populations (sus scrofa) are present in many regions of the world. large feral populations in north america and australia are principally derived from introduced domestic pigs. in europe, most wild boar are found in germany and poland. while wild swine are certainly a significant reservoir of infection for domestic swine diseases (for example, african swine fever virus in wild boar in sardinia), these swine generally do not constitute a major public health risk. brucella suis infectio ... | 1997 | 9501373 |
| the presence of rna splicing signals in the cdna construct of the e2 gene of classical swine fever virus affected its expression. | e2 is the major neutralizing antigen for classical swine fever virus (csfv) infection. previously, we have cloned and sequenced the e2 cdna of taiwan strain p97 by the reverse transcription-polymerase chain reaction (rt-pcr) method from csfv-infected tissue. the presence of rna splicing donor and acceptor sites were found in the cdna sequence. in this study, transfection of e2 cdna into mammalian cells resulted in the production of a spliced rna. site-directed mutagenesis of the donor and accept ... | 1997 | 9504767 |
| a new assay for classical swine fever virus based on cytopathogenicity in porcine kidney cell line fs-l3. | a new assay termed the dome disappearance method for classical swine fever virus (csfv) using fs-l3 cells with serum-free culture medium was developed. the csfv live vaccine gpe- strain grows well and shows a slight cytopathic effect (cpe) in fs-l3 cells. this cpe results in the disappearance of the unique fluid-filled multicellular domes on a single monolayer of fs-l3 cells. by using this phenomenon, dome disappearance, as a marker of infection, it was possible to determine the titers of csfv a ... | 1998 | 9506817 |
| deletion of a cd2-like gene, 8-dr, from african swine fever virus affects viral infection in domestic swine. | an african swine fever virus (asfv) gene with similarity to the t-lymphocyte surface antigen cd2 has been found in the pathogenic african isolate malawi lil-20/1 (open reading frame [orf] 8-dr) and a cell culture-adapted european virus, ba71v (orf ep402r) and has been shown to be responsible for the hemadsorption phenomenon observed for asfv-infected cells. the structural and functional similarities of the asfv gene product to cd2, a cellular protein involved in cell-cell adhesion and t-cell-med ... | 1998 | 9525608 |
| a novel method for pestivirus genotyping based on palindromic nucleotide substitutions in the 5'-untranslated region. | a simple and practical method was developed for pestivirus genotyping based on analysis of the secondary structures in the 5'-untranslated region (utr). three stable stem-loop structures, v1, v2 and v3, predicted by computer in the 5'-utr, included strictly conserved consensus base-pairings which are shared by all the genotypes of pestivirus or are characteristic to each genotype of pestivirus. on the basis of the palindromic nucleotide substitution at the secondary structural level, six genotyp ... | 1998 | 9562417 |
| evolution of viral dna-dependent dna polymerases. | dna viruses as their host cells require a dna-dependent dna polymerase (pol) to faithfully replicate their genomic information. large eukaryotic dna viruses as well as bacterial viruses encode a specific pol equipped with a proofreading 3'-5'-exonuclease, and other replication proteins. all known viral pol belong to family a and family b pol. common to all viral pol is the conservation of the 3'-5'-exonuclease domain manifested by the three sequence motifs exo i, exo ii, and exo iii. the polymer ... | 1998 | 9562890 |
| is the major capsid protein of iridoviruses a suitable target for the study of viral evolution? | iridoviruses are large cytoplasmic dna viruses that are specific for different insect or vertebrate hosts. the major structural component of the non-enveloped icosahedral virus particles is the major capsid protein (mcp) which appears to be highly conserved among members of the family iridoviridae, phycodnaviridae, and african swine fever virus. the amino acid sequences of the known mcps were used in comparative analyses to elucidate the phylogenic relationships between different cytoplasmic dna ... | 1998 | 9562891 |
| an experimental infection with classical swine fever virus in weaner pigs. i. transmission of the virus, course of the disease, and antibody response. | the spread of classical swine fever (csf) virus (strain lorraine), originally isolated in the first csf infected herd of the 1993-1994 belgian epizootic, was examined in an isolation unit with three adjacent pens and 15 weaner pigs per pen. virus was introduced through experimental inoculation of one weaner pig in the middle pen (pen 2). the experimentally inoculated pig became viraemic 4 days post-inoculation (dpi) and the pen mates at 12 (n = 9) and 14 dpi (n = 5). the first viraemia in pens 1 ... | 1998 | 9563158 |
| an experimental infection with a classical swine fever virus in weaner pigs. ii. the use of serological data to estimate the day of virus introduction in natural outbreaks. | in a companion paper a logistic regression model of seroprevalence over time was developed on the basis of data obtained during an experimental infection of weaner pigs with classical swine fever (csf) virus. the model was applied to seroprevalence data from three outbreaks of the 1993-1994 epizootic to test whether the model could predict correctly the day of virus introduction into the herd. it was concluded that the logistic regression model has potential as a tool to estimate in retrospect t ... | 1998 | 9563159 |
| the african swine fever virus proteins p54 and p30 are involved in two distinct steps of virus attachment and both contribute to the antibody-mediated protective immune response. | the nature of the initial interactions of african swine fever (asf) virus with target cells is only partially known, and to date only the asf virus protein p12 has been identified as a viral attachment protein. more recently, antibodies to viral proteins p54 and p30 have been shown to neutralize the virus, inhibiting virus binding and internalization, respectively. therefore, we investigated the role of these proteins in the receptor-mediated asf virus endocytosis in swine macrophages, the natur ... | 1998 | 9568043 |
| specific interaction of eukaryotic translation initiation factor 3 with the 5' nontranslated regions of hepatitis c virus and classical swine fever virus rnas. | translation of hepatitis c virus (hcv) and classical swine fever virus (csfv) rnas is initiated by cap-independent attachment (internal entry) of ribosomes to the approximately 350-nucleotide internal ribosomal entry segment (ires) at the 5' end of both rnas. eukaryotic initiation factor 3 (eif3) binds specifically to hcv and csfv iress and plays an essential role in the initiation process on them. here we report the results of chemical and enzymatic footprinting analyses of binary eif3-ires com ... | 1998 | 9573242 |
| complete genomic sequence of border disease virus, a pestivirus from sheep. | the genus pestivirus of the family flaviviridae comprises three established species, namely, bovine viral diarrhea virus (bvdv), classical swine fever virus (csfv), and border disease virus from sheep (bdv). in this study, we report the first complete nucleotide sequence of bdv, that of strain x818. the genome is 12,333 nucleotides long and contains one long open reading frame encoding 3, 895 amino acids. the 5' noncoding region (ncr) of bdv x818 consists of 372 nucleotides and is thus similar i ... | 1998 | 9573288 |
| the major structural protein of african swine fever virus, p73, is packaged into large structures, indicative of viral capsid or matrix precursors, on the endoplasmic reticulum. | african swine fever virus (asfv) is a large enveloped dna virus that shares the striking icosahedral symmetry of iridoviruses. to understand the mechanism of assembly of asfv, we have been studying the biosynthesis and subcellular distribution of p73, the major structural protein of asfv. sucrose density sedimentation of lysates prepared from infected cells showed that newly synthesized p73 was incorporated into a complex with a size of 150 to 250 kda. p73 synthesized by in vitro translation mig ... | 1998 | 9573294 |
| a recombinant classical swine fever virus stably expresses a marker gene. | the gene coding for bacterial chloramphenicol acetyltransferase (cat) was inserted in frame into the viral npro gene of the full-length cdna clone pa187-1 of the classical swine fever virus (csfv) strain alfort/187. rna transcribed in vitro from the resulting plasmid was transfected into sk-6 porcine kidney cells. infectious progeny virus va187-cat recovered from transfected cells had growth characteristics indistinguishable from those of parental virus va187-1. in cells infected with va187-cat ... | 1998 | 9573312 |
| inducible gene expression from african swine fever virus recombinants: analysis of the major capsid protein p72. | a method to study the function of individual african swine fever virus (asfv) gene products utilizing the escherichia coli lac repressor-operator system has been developed. recombinant viruses containing both the laci gene encoding the lac repressor and a strong virus late promoter modified by the insertion of one or two copies of the lac operator sequence at various positions were constructed. the ability of each modified promoter to regulate expression of the firefly luciferase gene was assaye ... | 1998 | 9580160 |
| expression of the glycoprotein e2 of the classical swine fever virus in escherichia coli. | the glycoprotein e2 sequences of classical swine fever virus (strain p97) were cloned, sequenced and expressed in e. coli. result from sds-polyacrylamide gel electrophoresis analysis of expressed proteins revealed the presence of a prominently stained band corresponding to a molecular mass of 61 kda, which is in agreement with the predicted size from the dna sequence. the recombinant e2 protein contained an aminoterminal tag of six histidines that could be used for purification by the nickel che ... | 1998 | 9592734 |
| [last remedy against hog cholera remains on the shelf]. | | 1997 | 9599160 |
| expression of african swine fever virus envelope protein j13l inhibits vaccinia virus morphogenesis. | the african swine fever virus (asfv) strain malawi lil20/1 open reading frame (orf) j13l was expressed in vaccinia virus (vv) from a strong synthetic late promoter as either a complete orf (vsj1) or lacking codons 1-31 (vsj2). each recombinant vv produced a small plaque which rapidly reverted to a normal size upon passage. the yield of infectious virus from a single cycle infection with vsj1 or vsj2 was reduced 50- to 100-fold compared to wild-type (wt) and a revertant virus (vsj5) in which the ... | 1998 | 9603332 |
| characterization of african swine fever virion proteins j5r and j13l: immuno-localization in virus particles and assembly sites. | the j5r open reading frame (orf) of the malawi lil 20/1 african swine fever virus (asfv) isolate encodes a 111 amino acid protein with a putative transmembrane domain at the n terminus. antisera raised against the predicted c-terminal peptide were used to identify the j5r protein by western blotting in cells infected with asfv or with recombinant vaccinia virus expressing the j5r orf. this showed that the j5r protein migrates with an apparent molecular mass of 23-25 kda, depending on the virus i ... | 1998 | 9603333 |
| a conserved african swine fever virus right variable region gene, l11l, is non-essential for growth in vitro and virulence in domestic swine. | the right variable region of the african swine fever virus (asfv) genome is known to contain genes with functions involving virus virulence and host range in swine. a novel open reading frame, orf l11l, which was absent in the non-pathogenic, cell culture-adapted european isolate ba71v, was identified in the pathogenic african isolate malawi lil-20/1. the location of l11l in the right variable region, together with its absence in ba71v, suggested that l11l may have a function in virus virulence ... | 1998 | 9603334 |
| cloning, expression and sequence analysis of the classical swine fever virus nucleocapsid protein. | the dna complementary to the 5'-terminal 1929 nucleotides of classical swine fever virus (csfv; alias hog cholera virus, hcv) lpc vaccine strain rna was cloned and sequenced. the sequence encompasses a 5'-noncoding region (ncr) of 264 nucleotides and an open reading frame (orf) of 1665 nucleotides. the cloned sequence contains genes of four viral proteins, p23, nucleocapsid (core) protein, e0 and part of e1 proteins. alignment of the 5'-terminal 1929 nucleotides of lpc strain with other strains ... | 1998 | 9608668 |
| the recombinant nucleocapsid protein of classical swine fever virus can act as a transcriptional regulator. | the cdna of the nucleocapsid (core) protein of classical swine fever virus (csfv) was generated by reverse transcription-polymerase chain reaction (rt-pcr) and cloned into a eukaryotic expression vector. the effect of the recombinant core protein on the transcriptional regulation of cellular as well as viral promoters was studied. using transient transfection assay, our results demonstrated that the core protein can activate the promoter of human heat shock protein 70 gene, and suppressed the sv ... | 1998 | 9617770 |
| differentiation of types 1a, 1b and 2 bovine viral diarrhoea virus (bvdv) by pcr. | there are two genotypes among bovine viral diarrhoea viruses (bvdv), bvdv1 and bvdv2. within the bvdv1 genotype there are two distinct subgenotypes, bvd1a and bvd1b. serology and monoclonal antibody binding are used to differentiate bvdv from classical swine fever virus (csfv) and border disease virus (bdv), the other members of the pestivirus genus. these techniques are less useful in the differentiation and segregation of viruses within the bvdv species. in this study, differential polymerase ... | 1998 | 9633045 |
| african swine fever: a disease characterized by apoptosis. | the cell tropism, organ distribution and resultant pathology of african swine fever were compared in domestic pigs infected with lethal (malawi) and sublethal (malta) isolates of african swine fever virus (asfv). after infections with both isolates, asfv was predominantly localized in cells of the mononuclear phagocytic system and was not observed in endothelial cells in lymphoid tissue. more severe tissue destruction and cell depletion, associated with high levels of infected macrophages, were ... | 1998 | 9634085 |
| the pathogenesis of african swine fever in the resistant bushpig. | bushpigs and warthogs are natural reservoir hosts of african swine fever virus (asfv) in the wild, showing no clinical signs of disease when infected with the same highly virulent isolates of asfv that induce rapid, haemorrhagic death in domestic pigs. in contrast to domestic pigs, infection of bushpigs with malawi isolate results in low levels of virus replication and lymphocyte apoptosis within the spleen, and a relatively low spread of virus to other lymphoid tissues. however, at 10 days post ... | 1998 | 9634086 |
| development of new cloning vectors for the production of immunogenic outer membrane fusion proteins in escherichia coli. | the pseudomonas aeruginosa lipoprotein gene (opri) was modified by cloning an in-frame polylinker in both orientations at the end of opri. the resulting plasmids pvub1 and pvub2 allow high lipoprotein production in e. coli after iptg induction. the modified lipoproteins are present in the outer membrane and surface-exposed. outer membrane-bound fusion proteins of different sizes were produced and used to generate antibodies without use of adjuvant. an 87 bp dna fragment from the vp72 capsid prot ... | 1996 | 9636324 |
| modulation of t cell and monocyte function in the spleen following infection of pigs with african swine fever virus. | infection of pigs with many strains of african swine fever virus (asfv) has been shown to cause a loss or marked decrease in the ability of splenocytes to respond to mitogens. these observations have been extended by cell fractionation and reconstitution experiments to show that the mitogen stimulated proliferative capacity of both the cd4+ and cd8+ t cells is affected. similarly, monocytes which are directly infectable by virus, are functionally defective as antigen presenting cells when added ... | 1998 | 9646434 |
| entry of african swine fever virus into vero cells and uncoating. | african swine fever virus (asfv) enters vero cells by adsorptive endocytosis [valdeira, m.l., geraldes, a., 1985. morphological study on the entry of african swine fever virus into cells, biol cell. 55, 35-40]. electron microscopy of a lysosomotropic drug-controlled penetration indicated that this step takes place in the endosomes, after fusion between the viral envelope and the limiting membrane of the endosome. inhibition studies with colcemid, cytochalasin b, sodium azide, dinitrophenol, lyso ... | 1998 | 9646445 |
| development and evaluation of a novel antigen capture assay for the detection of classical swine fever virus antigens. | an antigen-capture enzyme immunoassay (eia) was developed to detect classical swine fever virus (csfv) antigen directly from 10% w/v tissue suspension. the assay, based on the sandwich principle, uses a biotinylated monoclonal antibody bound to streptavidin-coated microplates as the capture system and a swine anti-csfv antibody and rabbit anti-swine hrpo-conjugate as the detector system. the antigen-capture eia was compared with conventional virus isolation and polymerase chain reaction (pcr) fo ... | 1998 | 9646447 |
| molecular characterization of the 3' noncoding region of classical swine fever virus vaccine strains. | the genomes of classical swine fever virus (csfv) vaccine strains are poorly characterized, and the mechanisms for their attenuation remain unknown. the aim of the present study was to characterize the 3' noncoding region (3' ncr) of a number of attenuated vaccine strains of csfv in order to examine changes in the viral genome after attenuation. the results showed that the 3' ncr:s of porcivac, rovac, russian lk and original chinese vaccine strain contain insertions very similar to that present ... | 1998 | 9654685 |
| low density blood granulocytic cells induced during classical swine fever are targets for virus infection. | classical swine fever virus infection of pigs causes a severe leukopenia and immunosuppression. in the present study, the kinetics of virus infection, and identification of target cells for the virus in peripheral blood were analysed. virus infection was often not detectable before 5-7 days p.i. a minority of animals yielded detectable infected cells at 3 days p.i., but < 5% pbmc. it was not until 10 days p.i. that this figure increased-to 35-70% pbmc depending on the animal. detailed analysis o ... | 1998 | 9656461 |
| membrane-anchored incorporation of a foreign protein in recombinant influenza virions. | the rna polymerase i system for in vivo synthesis of recombinant influenza vrna molecules was used for the expression of a chimeric protein, consisting of the 341-amino-acid ectodomain of the glycoprotein e2 of classical swine fever virus and the 37-amino-acid c-terminal membrane anchor of the influenza virus hemagglutinin (ha). during infection with an influenza a helper virus the amplified pseudo-viral rna was packaged into progeny virions together with influenza vrna segments. the foreign fus ... | 1998 | 9656996 |
| african swine fever virus infection of the bushpig (potamochoerus porcus) and its significance in the epidemiology of the disease. | warthog (phacochoerus aethiopicus), giant forest hog (hylochoerus meinertzhageni) and bushpig (potamochoerus porcus) are known to be susceptible to infection with african swine fever (asf) virus. little however, is known about the ecology of the disease in the bushpig. this study has shown that the bushpig remains viraemic for between 35 and 91 days following infection during which time it is able to infect the tick vector o. moubata. these ticks were able to transmit the disease to pigs. the vi ... | 1998 | 9659687 |
| [the situation of classical swine fever in wild boars in the european community and selected aspects of disease transmission]. | the situation of classical swine fever (csf) in europe is described on the basis of the literature. in the european community, csf is present among wild boars in germany (federal states mecklenburg-western pomerania, brandenburg and lower saxony), in france (northern vosges) and in italy (regio emìlìa romagna in 1997 and sardinia--enzootically infected). infected wild boars are important as a source of infection for domestic pigs in germany. selected aspects of the transmission of csf virus from ... | 1998 | 9674308 |
| a viral mechanism for inhibition of the cellular phosphatase calcineurin. | the transcription factor nfat (nuclear factor of activated t cells) controls the expression of many immunomodulatory proteins. african swine fever virus inhibits proinflammatory cytokine expression in infected macrophages, and a viral protein a238l was found to display the activity of the immunosuppressive drug cyclosporin a by inhibiting nfat-regulated gene transcription in vivo. this it does by binding the catalytic subunit of calcineurin and inhibiting calcineurin phosphatase activity. | 1998 | 9677199 |
| full-length gbv-c/hgv genomes from nine japanese isolates: characterization by comparative analyses. | the genomes of nine gbv-c/hgv isolates from japanese chronic hepatitis patients were fully sequenced and characterized. they shared 85% nucleotide sequence homology with previously characterized isolates from the us and west africa. homology studies and phylogenetic analyses showed that the japanese isolates formed a third group distinct from the established groups 1 and 2. the genetic distances between the three groups of gbv-c/hgv were very similar to the distances between the two classical sw ... | 1998 | 9687865 |
| border disease of sheep and goats. | border disease (bd) is a congenital virus disease of sheep and goats first reported in 1959 from the border region of england and wales. bd virus (bdv) is a pestivirus in the genus flaviviridae and is closely related to classical swine fever virus and bovine virus diarrhoea virus (bvdv). nearly all isolates of bdv are non-cytopathogenic (ncp) in cell culture. there are no defined serotypes but pestiviruses isolated from sheep exhibit considerable antigenic diversity and three distinct antigenic ... | 1998 | 9689745 |
| ultrastructural pathology of the bone marrow in pigs inoculated with a moderately virulent strain (dr'78) of african swine fever virus. | interpretation of changes in bone marrow during infectious processes is quite complex. this paper reports bone marrow lesions observed in pigs inoculated with a moderately virulent asf virus strain and studies their relationship to the pathogenesis of the disease. in this work, we have carried out the structural and ultrastructural study of the bone marrow of 14 large white x landrace pigs that were inoculated by the intramuscular route with 10(5) 50% hemodsorbing doses (had50) of the dominican ... | 1998 | 9690128 |
| macrophage culture: influence of species-specific incubation temperature. | cultured mammalian cells are traditionally maintained at 37 degrees c, despite the fact that core body temperatures differ considerably among mammals. considering the body temperature of the adult pig, comparison was made of porcine macrophage cultures maintained at 37 degrees c and 39.2 degrees c. examination of the cells showed that granularity was higher in macrophages maintained at 39.2 degrees c, although no differences in cell size were observed. the density of mhc class i and ii expressio ... | 1998 | 9692868 |
| a novel approach to the detection of classical swine fever virus by rt-pcr with a fluorogenic probe (taqman). | detection of classical swine fever virus (csfv) and its discrimination from other pestiviruses can be achieved by virus isolation (vi) in cell cultures, antigen detection, or molecular analysis. to simplify the latter, a 5'-nuclease assay (taqman) was developed for the rapid and specific detection of csfv with the minimum of downstream pcr processing. a pair of 5'-non-coding region, panpestivirus-specific pcr primers were assessed in a one-step reverse transcription-pcr with each of 36 diverse p ... | 1998 | 9694320 |
| detection of african swine fever virus in infected pig tissues by immunocytochemistry and in sity hybridisation. | the techniques for determining cellular sites of establishment and persistence of african swine fever virus (asfv) were established in susceptible domestic pigs and the resistant african reservoir hosts, the warthog and bushpig. detection, both in vitro and in vivo, was achieved by in situ hybridisation and immunocytochemistry, focusing principally on specific probes for vp73, a major capsid protein. hybridisation of radio-labelled probes for dna and rna was relatively insensitive and time consu ... | 1998 | 9694328 |
| migration of mitochondria to viral assembly sites in african swine fever virus-infected cells. | an examination by electron microscopy of the viral assembly sites in vero cells infected with african swine fever virus showed the presence of large clusters of mitochondria located in their proximity. these clusters surround viral factories that contain assembling particles but not factories where only precursor membranes are seen. immunofluorescence microscopy revealed that these accumulations of mitochondria are originated by a massive migration of the organelle to the virus assembly sites. v ... | 1998 | 9696857 |
| classical swine fever virus leader proteinase npro is not required for viral replication in cell culture. | the sequence encoding the viral leader proteinase npro was replaced by the murine ubiquitin gene in a full-length cdna clone of the classical swine fever virus (csfv) strain alfort/187. the recombinant virus va187-ubi showed growth characteristics similar to those of the parent va187-1 virus. at two occasions cells infected with va187-ubi exhibited a cytopathic effect and were found to contain a subgenomic viral rna. this rna lacked the same viral genes as the subgenomic rna which has been found ... | 1998 | 9696875 |
| [procoagulant activity in swine leukocytes, infected with the swine classical plague virus]. | an increased level of the procoagulant activity (pca) has been observed in porcine leukocytes in vitro infected with virulent or vaccine strains of hog cholera virus in comparison with intact cells. pca was similarly induced in infected leukocytes from swine immune to hog cholera virus. increased pca levels were detected in culture medium with leukocytes from intact and immune animals infected in vitro with both virulent and vaccine strains of hog cholera virus in comparison with the pca levels ... | 1998 | 9702815 |
| critical factors affecting the diagnostic reliability of enzyme-linked immunosorbent assay formats. | this paper aims to evaluate different formats of the enzyme-linked immunosorbent assays (elisas) for detection of virus-specific antibodies and focuses on factors that may influence the diagnostic reliability of such tests. newly developed and well-established elisas for detection of infections of bovine herpesvirus 1 (bhv1), bovine respiratory syncytial virus (brsv), classical swine fever virus (csfv), pseudorabies virus (prv) and bovine viral diarrhoea virus (bvdv) are used as examples. differ ... | 1998 | 9713894 |
| cholesterol affects african swine fever virus infection. | african swine fever virus (asfv) enters cells by receptor mediated endocytosis and requires a fusion event between the viral envelope and the limiting membrane of the endosome at low ph. in order to investigate the role of cholesterol in the early stages of asfv infection, we have studied the effect of the removal of cell and viral membrane cholesterol by cholesterol oxidase treatment of cells and virions, as well as the effect of some inhibitors of cholesterol synthesis on the infectious pathwa ... | 1998 | 9714715 |
| isolation and characterization of cytopathogenic classical swine fever virus (csfv). | two new classical swine fever virus (csfv) isolates obtained from naturally infected swine were found to exhibit a cytopathogenic (cp) phenotype. according to their reactivity with monoclonal antibodies (mabs) the isolates cpbw1 and cpmvp1 were classified as antigenic types "lothringen'92" and "flandern'90", respectively. in northern blot analyses and pcr assays csfv rna of subgenomic length was detected in infected cells indicating the presence of defective interfering particles. nucleotide seq ... | 1998 | 9722875 |
| serological and immunohistochemical study of african swine fever in wild boar in spain. | a serological and immunohistochemical study of african swine fever was carried out in wild boar killed in seven municipalities in the north of the province of córdoba during two hunting seasons (1991-92 and 1992-93), when the area was affected by the disease. fourteen of 147 wild boar analysed by elisa and immunoblotting had antibodies to african swine fever virus. the immunohistochemical study revealed that four cases (two seropositive and two seronegative) showed immunoreactivity to the anti-v ... | 1998 | 9725185 |
| intracellular virus dna distribution and the acquisition of the nucleoprotein core during african swine fever virus particle assembly: ultrastructural in situ hybridisation and dnase-gold labelling. | african swine fever virus (asfv) is a large complex icosahedral double-stranded dna virus that replicates in the cytoplasm of susceptible cells. assembly of new virus particles occurs within the perinuclear viroplasm bodies known as virus factories. two types of virus particle are routinely observed: "fulls," which are particles with an electron-dense dna-containing nucleoid, and "empties," which consist of the virus protein and membrane icosahedral shell but are without the incorporation of the ... | 1998 | 9740789 |
| pathogenesis of mucosal disease, a deadly disease of cattle caused by a pestivirus. | two biotypes of pestiviruses, cytopathogenic (cp) and non-cytopathogenic (noncp) viruses, are distinguished by their effects on tissue culture cells. in contrast to the bovine viral diarrhoea virus (bvdv) system, only a few cp border disease virus (bdv) and cp classical swine fever virus (csfv) strains have been described. antigenically closely related noncp and cp bvdv can be isolated from cattle with fatal mucosal disease (md) and are called a virus pair. the generation of cp bvdv in an animal ... | 1998 | 9741637 |