Publications

sero-surveillance of wild boar in the netherlands, 1996-1999.	from 1996 to 1999, blood samples were collected from wild boar shot during the hunting season in crown properties, national parks and the free wildlife belt in the netherlands. sera were screened for the presence of antibodies against classical swine fever virus (csfv), swine vesicular disease virus (svdv), aujeszky's disease virus (adv) and trichinella spiralis. the results of the sero-surveillance system indicate that csfv, svdv and adv are uncommon within the wild boar population. hence, the ...	2000	11107628
the inactivation of foot and mouth disease, aujeszky's disease and classical swine fever viruses in pig slurry.	the aim of the study was to investigate the decontamination of pig slurry containing exotic viruses of pigs, foot and mouth disease virus (fmdv), aujeszky's disease virus (adv) and classical swine fever virus (csfv). laboratory-scale decontamination experiments showed that fmdv, adv and csfv were heat inactivated in slurry within 3 min at 67 degrees c, 3 min at 62 degrees c and 3 min at 60 degrees c and in glasgow eagles medium within 5 min at 67 degrees c, 4 min at 65 degrees c and 2 min at 65 ...	2000	11119149
effects of infection of the tick ornithodoros moubata with african swine fever virus.	the effects of infection with african swine fever virus (asfv) on adult and nymphal ornithodoros moubata murray (ixodoidea, argasidae) ticks were examined. three groups of ticks were used, an uninfected control group, one group infected with the vic t90/1 isolate of asfv and another group infected with the liv 13/33 isolate of asfv. infection with asfv did not affect the oviposition rates of infected ticks when compared with uninfected ticks. there was no difference between infected and uninfect ...	2000	11129698
analysis of classical swine fever virus replication kinetics allows differentiation of highly virulent from avirulent strains.	to study the replication of classical swine fever virus (csfv) in cell culture, kinetics of viral plus-strand rna synthesis, of viral structural and non-structural protein expression as well as of secreted and cell-associated infectious virus were determined. highly virulent, moderately virulent and avirulent strains that were tested in standardized animal experiments to confirm their virulence were used to search for in vitro parameters allowing the differentiation of strains according to their ...	2000	10831853
rescue of infectious classical swine fever and foot-and-mouth disease virus by rna transfection and virus detection by rt-pcr after extended storage of samples in trizol.	a method for storing samples containing classical swine fever virus (csfv) or foot-and-mouth disease virus (fmdv), respectively, was developed, which abolishes the infectivity of both plus strand rna viruses, and allows storage of samples above 0 degrees c for an extended time, yet preserves the viral rna in a state which allows its detection by reverse transcription-polymerase chain reaction (rt-pcr), and even rescue of infectious virus after transfection of the extracted rna into susceptible c ...	2000	10856750
genetic grouping of classical swine fever virus by restriction fragment length polymorphism of the e2 gene.	a method for genetic grouping of classical swine fever viruses (csfv) was developed based on the restriction fragment length polymorphism (rflp) revealed by avaii, banii and pvuii digestion of rt-pcr amplified segments of the e2 gene. from inspection of the genetic sequences of thai isolates and reference strains, the rflp method was designed to be capable of differentiating all known genogroups and subgenogroups suggested by phylogenetic analysis of the csfv e2 gene. the method was applied to 6 ...	2000	10856761
apoptosis in the lymphatic organs of piglets inoculated with classical swine fever virus.	the involvement of apoptosis in the lymphatic organs of piglets infected with classical swine fever (csf) virus was investigated. piglets were inoculated with csf virus and 3, 5, 7 and 10 days post inoculation (dpi), the thymus, spleen and lymph node were examined. in the thymus cortex, macrophages phagocytizing the nuclear remnants or apoptotic bodies increased after 3 dpi. thymus atrophy due to the loss of the cortex increased markedly during the observation period. compact and shrunken nuclei ...	2000	10865147
mechanism of action of a pestivirus antiviral compound.	we report here the discovery of a small molecule inhibitor of pestivirus replication. the compound, designated vp32947, inhibits the replication of bovine viral diarrhea virus (bvdv) in cell culture at a 50% inhibitory concentration of approximately 20 nm. vp32947 inhibits both cytopathic and noncytopathic pestiviruses, including isolates of bvdv-1, bvdv-2, border disease virus, and classical swine fever virus. however, the compound shows no activity against viruses from unrelated virus groups. ...	2000	10869440
an outbreak of african swine fever in nigeria: virus isolation and molecular characterization of the vp72 gene of a first isolate from west africa.	the isolation of 98/asf/ng, a strain of african swine fever virus (asfv) associated with a 1998 epizootic in nigeria, is reported. this first isolate of the virus from west africa was identified through a successful polymerase chain reaction (pcr) amplification and sequencing of a 280 base pair (bp) fragment of the major capsid protein (vp72) gene. further amplification and sequence analysis of a 1.9 kilobase pair (kbp) fragment encompassing the complete vp72 gene showed that the isolate has a 9 ...	2000	10872875
pathogenesis of granulocytopenia and bone marrow atrophy during classical swine fever involves apoptosis and necrosis of uninfected cells.	granulocytopenia, a hematological hallmark of classical swine fever, is partially responsible for the suppression of innate immune defenses during classical swine fever. the present report demonstrates that this depletion was apparent as early as 3 days postinfection (p.i.). both mature peripheral and bone marrow neutrophils were affected, whereas immature neutrophils increased absolutely in the periphery and coincidentally immature myeloid progenitors in the bone marrow. these data suggest that ...	2000	10873748
experimental infections of rabbits with rabbit haemorrhagic disease virus monitored by polymerase chain reaction.	adult and 4-5-week-old rabbits were inoculated subcutaneously with rabbit haemorrhagic disease virus (rhdv). samples were prepared from various tissues at intervals postinoculation (pi) for the detection of viral rna and antigens. using a haemagglutination test (hat), viral antigens were detected in the liver, bile and spleen of the adult rabbits at and after 36 h pi. the reverse transcription-polymerase chain reaction (rt - pcr) showed that rhdvrna was present in the liver, bile and spleen as e ...	2000	10877972
pathogenesis of classical swine fever: renal haemorrhages and erythrodiapedesis.	thirty pigs were inoculated with a virulent isolate (quillota strain) of classical swine fever (hog cholera) virus to establish the chronological occurrence of lesions in the kidney and to determine the mechanism responsible for renal haemorrhages. the study included the use of histopathological, ultrastructural, immunohistochemical (detection of viral antigen gp55, mac387, lambda chains, cd3 and c1q) and morphometrical techniques (vascular area). renal interstitial oedema and haemorrhages were ...	2000	10906255
sequence analysis of e2 glycoprotein genes of classical swine fever viruses: identification of a novel genogroup in thailand.	thirty classical swine fever viruses (csfv) isolated in thailand between 1988 and 1996 were characterised by genetic sequence analysis of a part of their e2 coding regions, comparing the new data with that for representative reference viruses from other countries and continents. thai isolates were divided into three distinct genogroups, indicating multiple origins for the outbreaks. eighteen isolates from 1988-1995 form a new genogroup not previously described from any other geographical region. ...	2000	10916939
structure of african swine fever virus late promoters: requirement of a tata sequence at the initiation region.	a number of mutations, including deletions, linker scan substitutions, and point mutations, were performed in the promoter of the late african swine fever virus (asfv) gene coding for the capsid protein p72. the consequences of the mutations in terms of promoter activity were analyzed by luciferase assays using plasmids transfected into infected cells. the results showed that the promoter function is contained between nucleotides -36 and +5 relative to the transcription initiation site. moreover ...	2000	10933729
mechanism of inactivation of nf-kappa b by a viral homologue of i kappa b alpha. signal-induced release of i kappa b alpha results in binding of the viral homologue to nf-kappa b.	activation of the nuclear factor kappa b plays a key role in viral pathogenesis, resulting in inflammation and modulation of the immune response. we have previously shown that a238l, an open reading frame from african swine fever virus (asfv), encoding a protein with 40% homology to porcine i kappa b alpha exerts a potent anti-inflammatory effect in host macrophages, where it down-regulates nf-kappa b-dependent gene transcription and proinflammatory cytokine production. this paper reveals the me ...	2000	10934190
prevention of transplacental transmission of moderate-virulent classical swine fever virus after single or double vaccination with an e2 subunit vaccine.	the use of a vaccine against classical swine fever virus (csfv) during an outbreak of csf should lead to a reduction in the horizontal or vertical transmission of csfv. the reduction of vertical, i.e. transplacental, transmission of a moderate-virulent strain of csfv from the sow to its offspring was studied in sows vaccinated once or twice with a csfv e2 subunit vaccine. two groups of nine sows were vaccinated with one pd95 dose of the e2 subunit vaccine, approximately four weeks before insemin ...	2000	10952445
ultrastructural glomerular changes in experimental infection with the classical swine fever virus.	ultrastructural studies of glomerular changes were performed on 16 pigs experimentally infected with a highly virulent strain of the classical swine fever virus. our observations revealed the thickening of glomerular basement membranes, swelling of endothelial cells and cytoplasmic vacuolization within podocytes containing abundant viral particles. an early viral infection of podocytes was suggested as the cause of selective swelling of the foot processes of these cells with the consequent oblit ...	2000	10958244
detection of porcine enteroviruses by nrt-pcr: differentiation of cpe groups i-iii with specific primer sets.	porcine enteroviruses (pev) comprising at least 13 serotypes grouped into three species are described as causative agents of neurological disorders, fertility disorders, and dermal lesions of swine. despite their well-documented acid stability, enteric infection route, and similarity of clinical symptoms, most of the porcine enterovirus (pev) serotypes are set apart from the genus enterovirus of the picornaviridae. hence, pcr procedures used commonly to detect enteroviruses are not applicable to ...	2000	10960708
prospective characterization of full-length hepatitis c virus ns5a quasispecies during induction and combination antiviral therapy.	the hepatitis c virus (hcv) nonstructural 5a (ns5a) protein has been controversially implicated in the inherent resistance of hcv to interferon (ifn) antiviral therapy in clinical studies. in this study, the relationship between ns5a mutations and selection pressures before and during antiviral therapy and virologic response to therapy were investigated. full-length ns5a clones were sequenced from 20 hcv genotype 1-infected patients in a prospective, randomized clinical trial of ifn induction (d ...	2000	10982347
the cellular immune recognition of proteins expressed by an african swine fever virus random genomic library.	the cellular immune recognition of peptides expressed by an african swine fever virus (asfv) random genomic library has been studied. dna from the malawi (lil20/1) asfv isolate was randomly sheared by sonication, cloned into a plasmid vector downstream of a bacteriophage t7 promoter, and 72 recombinant plasmids were arbitrarily selected. these plasmids were transiently expressed following transfection into major histocompatibility complex (mhc) class i(+) class ii(-) matched pig skin cells, whic ...	2000	10986387
african swine fever virus protein a238l interacts with the cellular phosphatase calcineurin via a binding domain similar to that of nfat.	the african swine fever virus protein a238l inhibits activation of nfat transcription factor by binding calcineurin and inhibiting its phosphatase activity. nfat controls the expression of many immunomodulatory proteins. here we describe a 14-amino-acid region of a238l that is needed and sufficient for binding to calcineurin. by introducing mutations within this region, we have identified a motif (pxixitxc/s) required for a238l binding to calcineurin; a similar motif is found in nfat proteins. p ...	2000	11000210
passage of classical swine fever virus in cultured swine kidney cells selects virus variants that bind to heparan sulfate due to a single amino acid change in envelope protein e(rns).	infection of cells with classical swine fever virus (csfv) is mediated by the interaction of envelope glycoprotein e(rns) and e2 with the cell surface. in this report we studied the role of the cell surface glycoaminoglycans (gags), chondroitin sulfates a, b, and c (cs-a, -b, and -c), and heparan sulfate (hs) in the initial binding of csfv strain brescia to cells. removal of hs from the surface of swine kidney cells (sk6) by heparinase i treatment almost completely abolished infection of these c ...	2000	11000226
[the leukocyte count is a valuable parameter for detecting classical swine fever].	in this paper we describe a study of the use of the white blood cell count (wbcc) as a parameter for detecting outbreaks of classical swine fever (csf). meta-analysis of the results of challenge experiments revealed that oronasal infection of spf-pigs with the virulent csf virus (csfv) strains brescia or nl9201 resulted in a significant decrease in the average white blood cell count during the first week after inoculation of the virus. challenge of conventional finishing pigs and sows with the m ...	2000	11002499
bacterial lipoprotein based expression vectors as tools for the characterisation of african swine fever virus (asfv) antigens.	african swine fever virus (asfv) is the causative agent of an important pig disease for which protective mechanisms are still poorly understood. the present work was aimed at the characterisation of asfv antigens using previously reported vectors that allow their expression as fusion proteins with the bacterial lipoprotein opri. several recombinant clones induced sla-restricted, asfv-specific lymphoproliferation and one (a2) was demonstrated to stimulate asfv-specific ctl activity in vitro, in o ...	2000	11003474
characterization of lesions caused by a south american virulent isolate ('quillota') of the hog cholera virus.	in this study, macroscopic and histopathological lesions produced by a virulent south american isolate ('quillota') of hog cholera virus were studied. the virus was inoculated in doses of 10(5)tcid50 in each of 35 pigs of 20 kg live weight. the animals were slaughtered from 4 to 18 days post-inoculation. the presence of virus antigens in lymphatic tissue was confirmed by both direct immunofluorescence and avidin-biotin-peroxidase techniques in formalin-embedded tissue samples. histological secti ...	2000	11014061
csf virus in east anglia: where from?		2000	11014491
iridovirus homologues of cellular genes--implications for the molecular evolution of large dna viruses.	iridoviruses belong to the group of large cytoplasmic deoxyriboviruses and infect either insects or vertebrates. in analogy to other large dna viruses of eucaryotes it was found that iridoviruses encode a number of cellular protein homologues. the majority of these proteins represent orthologues of cellular enzymes involved in transcription, replication, and nucleotide metabolism. others may have the potential to interfere with cell cycle regulation or immune defence mechanisms of the host. this ...	2000	11022791
chimeric classical swine fever viruses containing envelope protein e(rns) or e2 of bovine viral diarrhoea virus protect pigs against challenge with csfv and induce a distinguishable antibody response.	three chimeric classical swine fever virus (csfv)/bovine viral diarrhoea virus (bvdv) full-length dna copies were constructed, based on the infectious dna copy of the csfv vaccine strain c. the antigenic region of e2 and/or the complete e(rns) gene were replaced by the analogous sequence of bvdv ii strain 5250. viable chimeric virus flc11, in which e(rns) was replaced, was directly recovered from supernatant of sk6.t7 cells transfected with full-length dna. viable chimeric virus flc9, in which e ...	2000	11027808
an experimental infection with classical swine fever in e2 sub-unit marker-vaccine vaccinated and in non-vaccinated pigs.	the clinical and virological protection induced by an e2 sub-unit marker-vaccine against classical swine fever (csf) was examined during an experimental infection in vaccinated and non-vaccinated pigs. forty-five pigs were equally distributed over three adjacent pens of an isolation unit, there was only indirect (airborne) contact between pigs in the different pens. in pen 3 all pigs were vaccinated twice with 4 weeks interval. pigs in pens 1 and 2 were not vaccinated. two weeks after booster va ...	2000	11027811
airborne transmission of classical swine fever virus under experimental conditions.	sixty-one pigs were housed in an isolation unit with three compartments and five pens. each compartment had its own ventilation system resulting in air currents flowing from compartment a (pens 1 to 3) towards compartment b (pen 4), but not towards compartment c (pen 5). classical swine fever virus was introduced by the experimental inoculation of one pig in the middle pen (pen 2) of compartment a. the virus infected the pigs in pen 4, following the prevalent air currents, and the compartmentali ...	2000	11195166
biochemical requirements of virus wrapping by the endoplasmic reticulum: involvement of atp and endoplasmic reticulum calcium store during envelopment of african swine fever virus.	enwrapment by membrane cisternae has emerged recently as a mechanism of envelopment for large enveloped dna viruses, such as herpesviruses, poxviruses, and african swine fever (asf) virus. for both asf virus and the poxviruses, wrapping is a multistage process initiated by the recruitment of capsid proteins onto membrane cisternae of the endoplasmic reticulum (er) or associated er-golgi intermediate membrane compartments. capsid assembly induces progressive bending of membrane cisternae into the ...	2000	10666244
[serosurveillance of notifiable veterinary diseases in wild boar in the netherlands].	during the hunting season 1996-1999, blood samples were collected from wild boar shot in the netherlands. sera were screened for presence of antibodies against classical swine fever virus (csfv), swine vesicular disease virus (svdv), aujeszky's disease virus (adv), and trichinella spiralis. the results indicate that csfv, svdv, and adv are uncommon in the wild boar population. therefore, it seems that csfv, svdv, and adv infection in the wild boar population is not an important reservoir in the ...	2000	10666784
effects of chlorine, iodine, and quaternary ammonium compound disinfectants on several exotic disease viruses.	the effects of three representative disinfectants, chlorine (sodium hypochlorite), iodine (potassium tetraglicine triiodide), and quaternary ammonium compound (didecyldimethylammonium chloride), on several exotic disease viruses were examined. the viruses used were four enveloped viruses (vesicular stomatitis virus, african swine fever virus, equine viral arteritis virus, and porcine reproductive and respiratory syndrome virus) and two non-enveloped viruses (swine vesicular disease virus (svdv) ...	2000	10676896
within-farm spread of classical swine fever virus--a blueprint for a stochastic simulation model.	a stochastic simulation model to investigate the transmission of classical swine fever (csf) virus within an infected farm is described. the model is structured according to the processes that occur within and between management groups (pig units or houses). it uses the individual pig as the unit of interest and estimates the number of animals in the states 'susceptible', 'infected', 'infectious', and 'removed' for each day of the disease incident. probabilities are assigned to the transitions b ...	2000	10682386
protection of pigs against classical swine fever with dna-delivered gp55.	classical swine fever virus causes significant mortality and morbidity in commercial piggeries in many countries in europe and asia. the protective antigen, gp55, is highly conformation-dependent and thus killed virus or bacterially produced proteins are not protective. this report demonstrates that dna vaccination with the gene encoding gp55 can provide protective immunity with inoculation of two doses of 25 microg dna or a single shot of 200 microg. furthermore, the dna can be delivered intram ...	2000	10699343
[laboratory findings during the classic swine fever epidemic of 1997-1998].	the results of the laboratory tests carried out by the institute for animal science and health (id-lelystad), the netherlands, on samples collected during the classical swine fever (csf) epidemic 1997-1998 are summarized in this article. the relevance of the different laboratory tests and various samples collected on the eradication of csf during an outbreak is evaluated.	2000	10705606
classical swine fever virus e(rns) deletion mutants: trans-complementation and potential use as nontransmissible, modified, live-attenuated marker vaccines.	an sk6 cell line (sk6c26) which constitutively expressed the glycoprotein e(rns) of classical swine fever virus (csfv) was used to rescue csfv e(rns) deletion mutants based on the infectious copy of csfv strain c. the biochemical properties of e(rns) from this cell line were indistinguishable from those of csfv e(rns). two e(rns) deletion mutants were constructed, virus flc23 and virus flc22. virus flc23 encoded only the utmost n- and c-terminal amino acids of e(rns) (deletion of 215 amino acids ...	2000	10708411
recombinant classical swine fever (csf) viruses derived from the chinese vaccine strain (c-strain) of csf virus retain their avirulent and immunogenic characteristics.	two recombinant classical swine fever (csf) viruses (flc2, flc3) transcribed from a dna copy of the genome of the chinese (c) strain, a csf virus vaccine strain, were characterized in vivo in rabbits and pigs. rabbits were inoculated intravenously with flc2 or flc3, the parent c-strain virus, a biologically cloned c-strain or csf virus strain brescia (c.1.1.1). after 24-96 h fever was detected in the rabbits inoculated with the different c-strain viruses. apart from those in the control group, a ...	2000	10738091
transient classical swine fever virus infection in wild boar piglets partially protected by maternal antibodies.	an experimental study was conducted to investigate the clinical course of classical swine fever (csf) in wild boar piglets partially protected by maternal antibodies. five healthy wild boar piglets with a low serum titre of colostral antibodies against csf virus were challenged with virulent csf virus at the age of three months. apart of reduced food intake and diarrhoea no major clinical symptoms were noticed after challenge. these signs were seen during the second and third week of infection, ...	2000	10743336
an arid family protein binds to the african swine fever virus encoded ubiquitin conjugating enzyme, ubcv1.	the nh(2)-terminal end of a protein, named smcp, which contains an arid (a/t rich interaction domain) dna binding domain and is similar to the mammalian smcy/smcx proteins and retinoblastoma binding protein 2, was shown to bind the african swine fever virus encoded ubiquitin conjugating enzyme (ubcv1) using the yeast two hybrid system and in in vitro binding assays. antisera raised against the smcp protein were used to show that the protein is present in the cell nucleus. immunofluorescence show ...	2000	10760505
[synthesis and immunochemical properties of the recombinant major surface glycoprotein e2 of the classical swine fever virus].	recombinant e2 protein from vaccine strain of classical swine fever virus (csfv) and from scfv virulent strain shimen was synthesized in sf-21 and high-five cell culture with baculovirus as the expressing vector. for secretion, hydrophobic c-terminal transmembrane domain was removed and n-terminal signal polypeptide of 38 amino acids was added. maximum accumulation of recombinant products in sf-21 cells was observed after 48 h and in medium 96 h after infection with recombinant baculovirus. in h ...	2000	10765548
[use of recombinant protein e2 of the classical swine fever virus for immunization of animals].	recombinant major surface glycoprotein e2 from virulent shimen strain of classical swine fever virus (csfv) has been tested for immunogenicity in animal immunization experiments. immunization of 3-month-old piglets with 200 micrograms of recombinant protein protected the animals from lethal challenge with virulent csfv strain. csfv-specific antibody detection test based on competitive elisa has been developed using the recombinant e2 protein. the test can evaluate specific antibody levels after ...	2000	10765549
introduction to classical swine fever: virus, disease and control policy.	classical swine fever virus is a spherical enveloped particle of about 40-60 nm in diameter with a single stranded rna genome of about 12,300 bases with positive polarity, classified as a pestivirus within the family flaviviridae. natural hosts are domestic and wild pigs. the virus causes one of the most severe diseases in pigs world wide with grave economic consequences. the clinical picture of classical swine fever is variable, depending on the age of the affected animals and viral virulence. ...	2000	10785320
structure and presentation of a world wide web database of csf virus isolates held at the eu reference laboratory.	a computerized database was generated with the epidemiological data of more than 600 csf virus strains and isolates kept in the eu reference laboratory for classical swine fever in hanover. in addition, as sequence data from defined regions of the genome are increasingly being used for genetic typing of new isolates and are thus being published, it was decided to integrate them into the database. in order to make the epidemiological and the sequence data available to other laboratories through t ...	2000	10785323
genetic typing of classical swine fever virus.	three regions of the classical swine fever virus (csfv) genome that have been widely sequenced were compared with respect to their ability to discriminate between isolates and to segregate viruses into genetic groups. sequence data-sets were assembled for 55 csfvs comprising 150 nucleotides of the 5' non-translated region, 190 nucleotides of the e2 envelope glycoprotein gene and 409 nucleotides of the ns5b polymerase gene. phylogenetic analysis of each data-set revealed similar groups and subgro ...	2000	10785324
classical swine fever virus: a ring test to evaluate rt-pcr detection methods.	six laboratories participated in an exercise to compare the sensitivity and specificity of rt-pcr tests for the detection of classical swine fever virus (csfv). two sets of coded samples were prepared by serial dilution of positive samples and then distributed to each of the laboratories. one set comprised 34 samples of random primed cdna. these had been synthesised from viral rna representative of seven different genetic subtypes of csfv. the other set comprised 40 clinical samples containing t ...	2000	10785325
survival and inactivation of classical swine fever virus.	classical swine fever virus, like many enveloped viruses, may be regarded as moderately fragile. it shows a short but variable survival time in the environment, depending on physical conditions, but may remain viable for prolonged periods in favourable circumstances as found, for example, in stored meat. published information is reviewed on the survival time of the virus under a variety of physical and chemical conditions, including the variable influence of environmental factors. the principles ...	2000	10785326
laboratory experience during the classical swine fever virus epizootic in the netherlands in 1997-1998.	from february 1997 till may 1998 the national reference laboratory for classical swine fever (csf) in the netherlands was confronted with millions of samples taken from pigs during an outbreak of csf in a pig dense region. in a limited period major logistic problems needed to be solved regarding the processing of samples and information at the laboratory facilities. in total over 2.3 million samples were examined by different csf diagnostic methods. the majority (approximately 2.1 million) of th ...	2000	10785328
development of a classical swine fever subunit marker vaccine and companion diagnostic test.	the development of a classical swine fever (csf) subunit marker vaccine, based on viral envelope glycoprotein e2, and a companion diagnostic test, based on a second viral envelope glycoprotein e(rns), will be described. important properties of the vaccine, such as onset and duration of immunity, and prevention of horizontal and vertical transmission of virus were evaluated. a single dose of the vaccine protected pigs against clinical signs of csf, following intranasal challenge with 100ld(50) of ...	2000	10785329
susceptibility of piglets to rabbit hemorrhagic disease virus following experimental infection.	the possibility exists that rabbit hemorrhagic disease virus (rhdv) can be transmitted to swine, through lapinized hog cholera virus (hcv) vaccine. to investigate the infectivity of rhdv in swine, 16 four- to six-week-old piglets were inoculated subcutaneously with rhdv, and samples of liver, lung, spleen, kidney, bile, adrenal gland, tonsil, mesenteric lymph node, thymus, urine, buffy coat, and feces were collected from each of 2 animals on days 0, 1, 2, 3, 5, 7, 14, and 28 post infection. usin ...	2000	10805254
detection of low-virulent classical swine fever virus in blood of experimentally infected animals: comparison of different methods.	the effectiveness of virus isolation, commercial antigen enzyme-linked immunosorbent assay (elisa), reverse transcriptase-polymerase chain reaction (rt-pcr), and flow cytometry in detection of a low-virulent classical swine fever virus (csfv) in blood in the early period of infection was evaluated. domestic pigs at the age of 6-8 weeks and young wild boars were inoculated with a low-virulent field isolate of csfv originating from a wild boar. this virus induced serious clinical reaction in only ...	1999	10825927
african swine fever virus infection induces tumor necrosis factor alpha production: implications in pathogenesis.	we have analyzed the production of tumor necrosis factor alpha (tnf-alpha) induced by in vitro infection with african swine fever (asf) virus (asfv) and the systemic and local release of this inflammatory cytokine upon in vivo infection. an early increase in tnf-alpha mrna expression was detected in asfv-infected alveolar macrophages, and high levels of tnf-alpha protein were detected by elisa in culture supernatants from these cells. when animals were experimentally infected with a virulent iso ...	1999	9971800
a lipid modified ubiquitin is packaged into particles of several enveloped viruses.	an anti-ubiquitin cross-reactive protein which migrates more slowly (6.5 kda) by sds-page than ubiquitin was identified in african swine fever virus particles. this protein was extracted into the detergent phase in triton x-114 phase separations, showing that it is hydrophobic, and was radiolabelled with both [3h]palmitic acid and [32p]orthophosphate. this indicates that the protein has a similar structure to the membrane associated phosphatidyl ubiquitin described in baculovirus particles. a si ...	1999	10037162
oral immunisation of swine with a classical swine fever vaccine (chinese strain) and transmission studies in rabbits and sheep.	seven experiments including a total of 47 pigs, 11 wild boars, 26 rabbits, 10 hares and 16 sheep were carried out to assess the efficacy, safety and transmission of the chinese vaccine strain of the classical swine fever virus (csfv) administrated by the oral route. within 3 weeks after oral vaccination, a clear seroconversion occurred in the pigs. six weeks after vaccination, vaccinated pigs were fully protected against a virulent challenge. the c-strain was not isolated from tonsils, spleen, l ...	1999	10063532
genetic heterogeneity of porcine and ruminant pestiviruses mainly isolated in japan.	the genetic variability of porcine and ruminant pestiviruses was studied by comparative nucleotide sequence analysis of 73 isolates (42 porcine and 31 ruminant), including 65 japanese isolates (35 porcine and 30 ruminant). the 5'-untranslated region (utr) amplified by reverse transcriptase-polymerase chain reaction (rt-pcr) was determined by direct sequencing and phylogenetic analysis was performed from the nucleotide sequence data. most porcine isolates were divided into two major subgroups, cl ...	1999	10068129
an experimental marker vaccine and accompanying serological diagnostic test both based on envelope glycoprotein e2 of classical swine fever virus (csfv).	envelope glycoprotein e2 is the most immunogenic protein of classical swine fever virus (csfv). in a proposed model of the antigenic structure of e2, the n-terminal half of e2 forms two independent structural antigenic units, a and bc. e2 without transmembrane region (e2-tmr) is expressed and secreted into the medium of insect cells by use of the baculovirus expression system. the immune response induced by e2 protects pigs against csfv. recently, we showed that the protective immune response to ...	1999	10073720
incidence of classical swine fever (csf) in wild boar in a densely populated area indicating csf virus persistence as a mechanism for virus perpetuation.	a virological survey was carried out to establish the distribution of classical swine fever (csf) virus among wild boar in the federal state of brandenburg, germany. organ materials and blood samples were collected from 11,670 wild boar shot or found dead during the period march 1995 to december 1997. in total 211 (1.8%) wild boar were positive for csf virus or antigen. the incidence of csf-positive animals decreased continuously from 4.6% at the beginning of the epidemic in 1995 to 0.7% in 1997 ...	1999	10085775
nuclear and nucleolar localization of an african swine fever virus protein, i14l, that is similar to the herpes simplex virus-encoded virulence factor icp34.5.	pcr analysis of the genomes of 18 different african swine fever virus (asfv) isolates showed that the i14l open reading frame (orf) was present as either a long form or short form in all of the isolates. sequencing of the orf from eight isolates confirmed that both forms of the orf were well conserved. antisera raised against the i14l protein identified the long form of the protein as a 21 kda protein expressed late during asfv infection. immunofluorescent analysis of transiently expressed haema ...	1999	10091989
[comparison of laboratory diagnostic methods for the detection of infection with the virus of classical swine fever in the early inspection phase: an experimental study].	virus isolation in the pk-15 cell culture, two commercial antigen elisas, reverse transcriptional-polymerase chain reaction (rt-pcr), and flow cytometry have been evaluated to detect viremic pigs in the early period of classical swine fever virus (csfv) infection. domestic pigs were experimentally inoculated with the virulent csfv strain 'alfort 187' and two field isolates. csfv isolation and rt-pcr were found to be the most sensitive methods for the detection of highly virulent csfv in the earl ...	1999	10189722
[detection of the hog cholera virus using the polymerase chain reaction].	a rapid and highly sensitive method for detecting hog cholera virus (hcv) based on a reverse transcription of the polymerase chain reaction (rt-pcr) is developed. primers complementary to the most homologous sites of virus genome in an area coding the precursor for glycoproteins gp44/gp48 are selected. detection of the virus in pathological material by the rt-pcr showed that use of these primers in amplification allows detection of different hcv strains.	1999	10190108
selective stimulation of hepatitis c virus and pestivirus ns5b rna polymerase activity by gtp.	ns5b of the hepatitis c virus is an rna template-dependent rna polymerase and therefore the key player of the viral replicase complex. using a highly purified enzyme expressed with recombinant baculoviruses in insect cells, we demonstrate a stimulation of rna synthesis up to 2 orders of magnitude by high concentrations of gtp but not with atp, ctp, utp, gdp, or gmp. enhancement of rna synthesis was found with various heteropolymeric rna templates, with poly(c)-oligo(g)12 but not with poly(a)-oli ...	1999	10196156
recovery of infectious classical swine fever virus (csfv) from full-length genomic cdna clones by a swine kidney cell line expressing bacteriophage t7 rna polymerase.	a new method for the recovery of infectious classical swine fever virus (csfv) from full-length genomic cdna clones of the c-strain was developed. classical reverse genetics is based on transfection of in vitro transcribed rna to target cells to recover rna viruses. however, the specific infectivity of such in vitro transcribed rna in swine kidney cells is usually low. to improve reverse genetics for csfv, a stable swine kidney cell line was established that expresses cytoplasmic bacteriophage t ...	1999	10204702
efficacy and stability of a subunit vaccine based on glycoprotein e2 of classical swine fever virus.	the purpose of this study was to determine the efficacy and stability of an e2 subunit vaccine against classical swine fever virus (csfv). the vaccine, which contains e2 produced in insect cells by a baculovirus expression vector is a potential marker vaccine, as it allows discrimination between infected and vaccinated pigs. several vaccination-challenge experiments were performed to determine the dose that protects 95% of the vaccinated pigs (pd95), and to determine the stability and efficacy o ...	1999	10227472
[classical swine fever in wild boars in switzerland].	in may 1998, wild boars with classical swine fever (csf) symptoms were detected in the southern part (canton ticino) of switzerland. csf virus was isolated from the submitted samples and rt-pcr followed by direct nucleotide sequencing of the 5' non-translated region showed that this virus was identical to the isolate previously recognized in wild boars from the area of varese (italy). in most animals, antibodies to csf virus were detected as well. an immediate measurement was taken by limiting t ...	1999	10228397
the biological effects induced in mice by p36, a proteinaceous factor of virulence produced by african swine fever virus, are mediated by interleukin-4 and also to a lesser extent by interleukin-10.	we have previously presented indirect evidence that both specific immunosuppression and lymphocyte mitogenicity induced in mice by p36, a proteinaceous factor of virulence produced by porcine monocytes infected by african swine fever virus, were consistent with a th2-driven response. here we show: (1) interleukin-4 (il-4) and interleukin-10 (il-10) mrna expression in the spleen and thymus of c57bl/6 mice were displayed early after p36 inoculation. the expression of thymic il-10 mrna occurred, ho ...	1999	10233720
ns5a, a nonstructural protein of hepatitis c virus, binds growth factor receptor-bound protein 2 adaptor protein in a src homology 3 domain/ligand-dependent manner and perturbs mitogenic signaling.	although hepatitis c virus (hcv) infection is an emerging global epidemic causing severe liver disorders, the molecular mechanisms of hcv pathogenesis remain elusive. the ns5a nonstructural protein of hcv contains several proline-rich sequences consistent with src homology (sh) 3-binding sites found in cellular signaling molecules. here, we demonstrate that ns5a specifically bound to growth factor receptor-bound protein 2 (grb2) adaptor protein. immunoblot analysis of anti-grb2 immune complexes ...	1999	10318918
closed one-tube reverse transcription nested polymerase chain reaction for the detection of pestiviral rna with fluorescent probes.	an assay was developed in which reverse transcription (rt), nested polymerase chain reaction (pcr) and accumulation of amplicon-specific fluorescence could take place in a single, closed reaction tube. the assay, which was classical swine fever virus rna-specific, was compared with other methods for detection of this virus, including various rt-pcr configurations, virus isolation and elisa. the new method was very sensitive, and less prone to giving false positive results compared to nested pcr ...	1999	10328538
replication of african swine fever virus dna in infected cells.	we have examined the ultrastructural localization of african swine fever virus dna in thin-sections of infected cells by in situ hybridization and autoradiography. virus-specific dna sequences were found in the nucleus of infected vero cells at early times in the synthesis of the viral dna, forming dense foci localized in proximity to the nuclear membrane. at later times, the viral dna was found exclusively in the cytoplasm. electron microscopic autoradiography of african swine fever virus-infec ...	1999	10329562
localization of pestiviral envelope proteins e(rns) and e2 at the cell surface and on isolated particles.	the glycoproteins e(rns) of classical swine fever virus (csfv) and e(rns) and e2 of bovine viral diarrhoea virus (bvdv) are shown to be located at the surface of infected cells by the use of indirect immunofluorescence and by cytofluorometric analysis. the positive immunostaining of the cell surface was further analysed by immunogold electron microscopy and it could be shown that only extracellular virions were labelled. gold granules were not seen at the cellular plasma membrane. in contrast to ...	1999	10355762
[use of monoclonal antibodies for studying the classical hog cholera virus].	numerous monoclonal antibodies (mab) to hog cholera virus are a highly specific and effective instrument for studies of this agent. panels of mab for differential diagnosis of pestiviruses are characterized. international reference panel of 30 mabs is a result of cooperation of european scientists; it was approved as the official reference for assessing all available and new diagnostic agents. mab permit intraspecies differentiation between hog cholera virus strains and, which is particularly im ...	1999	10358897
the african swine fever virus prenyltransferase is an integral membrane trans-geranylgeranyl-diphosphate synthase.	in a previous study, it was shown that the protein encoded by the gene b318l of african swine fever virus (asfv) is a trans-prenyltransferase that catalyzes in vitro the condensation of farnesyl diphosphate and isopentenyl diphosphate to synthesize geranylgeranyl diphosphate and longer chain prenyl diphosphates (alejo, a., yáñez, r. j., rodríguez, j. m., viñuela, e., and salas, m. l. (1997) j. biol. chem. 272, 9417-9423). to investigate the in vivo function of the viral enzyme, we have determine ...	1999	10364254
african swine fever virus: a b cell-mitogenic virus in vivo and in vitro.	the two major characteristics of pathogenesis in african swine fever virus (asfv) infections of domestic pigs are massive b-cell apoptosis and haemorrhage. the effects of asfv on porcine b cells have therefore been systematically examined in vivo, by using virus-infected pigs and scid-beige mice reconstituted with porcine bone marrow, and in vitro, by using porcine b-cell lines and b cells from normal and asfv-infected pigs. secretion of porcine ig was stimulated by asfv both in vivo and in bone ...	1999	10374963
mutations in the ns5a gene predict response to interferon therapy in japanese patients with chronic hepatitis c and cirrhosis.	the virus genotype, serum hcv-rna level and liver histology are reported to be important factors in the response to interferon therapy. recent studies have revealed that hcv ns5a 2209-2248 amino acid changes affect the response to interferon therapy of genotype 1b chronic hepatitis c. in contrast, some studies done in western countries have reported no such correlation. in the present study, interferon therapy was given to 58 japanese patients, including 15 liver cirrhosis patients. ns5a 2209-22 ...	1999	10381214
comparative sequence analysis of classical swine fever virus isolates from the epizootic in the netherlands in 1997-1998.	sixteen classical swine fever virus (csfv) field isolates from outbreaks of classical swine fever from the period between february 1997 and march 1998 in the netherlands were sequence analysed. parts of the 5' noncoding region (5'ncr) and the e1/e2 gene were sequenced after rt-pcr. the obtained sequences were compared with isolates of recent outbreaks in europe and those of former outbreaks in the netherlands. sequence alignment of the 5'ncr region (321 bp) revealed that the isolates of the dutc ...	1999	10384890
genetic variation in the 5' end and ns5b regions of classical swine fever virus genome among japanese isolates.	sixteen clinical strains of classical swine fever virus (csfv) isolated in japan were subjected to analyses of nucleotide sequence variations in the 5' end and ns5b regions of the genome. these isolates were divided into three genovars, csfv-1, csfv-2 and csfv-3, based on palindromic nucleotide substitutions at the three variable loci in the 5' untranslated region (utr). phylogenetic trees constructed from nucleotide sequences in the 5'-utr and ns5b gene indicated that the csfv strains were divi ...	1999	10385204
virus antigen expression and alterations in peripheral blood mononuclear cell subpopulations after classical swine fever virus infection.	depletion in the number of lymphocytes and viral persistence are thought to be the most important outcomes of classical swine fever virus (csfv) infection. to define the change in peripheral blood mononuclear cells (pbmc) and virus replication in leukocytes after csfv infection, 8-week old pigs were infected with the lpc vaccine strain or virulent csfv (hcv-yl strain). changes in the relative number of pbmcs were analyzed by flow cytometry. the results showed a significant increase in the relati ...	1999	10392774
[genetic characteristics of the kc vaccine strain of hog cholera virus: comparative analysis of the primary sequence of surface glycoprotein e(rns), e1, and e2 genes].	primary structure of a genome fragment of attenuated strain cs of hog cholera virus (hcv) coding for three surface glycoproteins erns, e1, and e2 (fragment size 2379 nucleotides) is analyzed. by the nucleotide sequence the homology between strain cs and ten other virulent and attenuated hcv strains in this area is 84.9-94.6%, 87.2-94.6% in gene erns, 84.6-96.9% in gene e1, and 83.3-94.3% in gene e2. by amino acid sequence the homology is 90.9-94.3%, 92.9-95.0%, 92.3-95.6%, and 88.9-94.1%, respec ...	1999	10396731
genetic analysis of pestiviruses at the 3' end of the genome.	specific pcr primers were selected for each pestivirus genotype which flanked the 3'-part of the ns5b gene and more than three quarters of the 3'-utr. pcr products were sequenced in both directions using an automatic sequencing device and analyzed by computer package program dnastar. a comparative analysis of the 3' untranslated region (3'-utr) of 82 viruses, representing the four genotypes of the pestivirus genus, provided a similar phylogenetic grouping as other genomic regions. intertypic rec ...	1999	10403696
prevalence of gbv-c/hepatitis g virus rna and e2 antibody among subjects infected with human immunodeficiency virus type 1 after parenteral or sexual exposure.	gb virus c (gbv-c) or hepatitis g virus (hgv) is transmitted by the parenteral route but the importance of sexual transmission needs to be ascertained. gbv-c/hgv infections were investigated using rna and e2-antibody detection methods in 80 subjects infected by the human immunodeficiency virus type 1 (hiv-1) divided into 4 groups of 20 individuals each according to their main risk factor for hiv-1 infection: blood product recipients (group 1), intravenous drug users (group 2), homosexuals (group ...	1999	10421404
phenotypic analysis of peripheral leukocytes in piglets infected with classical swine fever virus.	the phenotypic changes in circulating leukocytes in swine fever influenced by classical swine fever virus (csfv) infection with different strain virulence was studied in piglets. the phenotypic differences were measured by monoclonal antibodies specific for porcine differentiation antigens. the pattern of phenotypic change varied with the virulence of csfv. infection with virulent, but not the attenuated strain of csfv resulted in the dramatic early loss of cd8-bearing t lymphocytes from the cir ...	1999	10425241
laboratory-scale inactivation of african swine fever virus and swine vesicular disease virus in pig slurry.	two methods were evaluated for the inactivation of african swine fever (asv) and swine vesicular disease (svd) viruses in pig slurry: chemical treatment and heat treatment. the addition of naoh or ca(oh)2 at different concentration/time combinations at 4 degrees c and 22 degrees c was examined, as was virus stability at different temperature/time combinations. asf virus (asfv) was less resistant to both methods than svd virus (svdv). in slurry from one source, asfv was inactivated at 65 degrees ...	1999	10432596
cytopathogenic and noncytopathogenic rna replicons of classical swine fever virus.	to determine the minimal requirements for autonomous rna replication of classical swine fever virus (csfv), genomes having in-frame deletions within the genes for structural and flanking nonstructural proteins were constructed, based on an infectious cdna clone of csfv alfort/187. rna was transcribed in vitro from the respective plasmids and transfected into sk-6 swine kidney cells. the replication competence of the rna was determined by immunostaining transfected cells for csfv ns3 protein and ...	1999	10438869
classical swine fever in sardinia: epidemiology of recent outbreaks.	a variable region of the gene encoding the major glycoprotein (e2) of classical swine fever virus (csfv) was sequenced from 12 sardinian isolates which had been obtained from three geographically distinct regions of the island. phylogenetic analysis of these viruses and others characterized in previous studies [1, 2] indicated that (a) the sardinian viruses were all members of the common european subgroup 2.3 and were clearly distinct from live vaccines recently used in this area; (b) they could ...	1999	10459661
transmission of classical swine fever virus by artificial insemination.	classical swine fever (csf) virus was introduced into an artificial insemination centre during the csf epizootic of 1997-1998 in the netherlands. the risk of further spread of csf virus via contaminated semen was recognised, but could not be assessed because scientific data on this issue were not available. an animal experiment was performed to determine whether csf virus could be transmitted via artificial insemination with contaminated semen. three boars were inoculated with a csf virus field ...	1999	10466500
design and construction of african swine fever virus chimeras incorporating foreign viral epitopes.	in the present work we have studied the feasibility of introducing foreign epitopes into the african swine fever virus (asfv) particle by genetic manipulation of the virus. for this purpose, we developed specific transfer vectors containing the gene encoding for the highly antigenic structural asfv protein p54 in which foreign sequences were introduced. dna sequences encoding continuous linear epitopes, the antigenic site a from foot-and-mouth disease virus (fmdv) vp1 protein and the da3 antigen ...	1999	10481737
virus-specific cell receptors are necessary, but not sufficient, to confer cell susceptibility to african swine fever virus.	the entry of african swine fever (asf) virus into vero cells and swine macrophages is mediated by saturable binding sites located in the plasma membrane, which have been related, as in other virus-cell systems, to the sensitivity of the cell to the virus. in order to define this correlation, we have analyzed up to 16 cell lines derived from different species for their sensitivity to virus infection, to determine the step in the virus infective cycle that was blocked in each resistant cell, the p ...	1999	10481739
african swine fever virus replication in the midgut epithelium is required for infection of ornithodoros ticks.	although the malawi lil20/1 (mal) strain of african swine fever virus (asfv) was isolated from ornithodoros sp. ticks, our attempts to experimentally infect ticks by feeding them this strain failed. ten different collections of ornithodorus porcinus porcinus ticks and one collection of o. porcinus domesticus ticks were orally exposed to a high titer of mal. at 3 weeks postinoculation (p.i.), <25% of the ticks contained detectable virus, with viral titers of <4 log(10) 50% hemadsorbing doses/ml. ...	1999	10482612
immunohistochemical detection of hog cholera virus antigen in paraffin wax-embedded tissues from naturally infected pigs.	in 17 pigs submitted for diagnosis in 1980, hog cholera was confirmed by viral isolation, by a direct immunofluorescent antibody test for viral antigen, and by the presence of characteristic histopathological lesions. in the present study, hog cholera viral antigen was demonstrated in these pigs by immunohistochemical examination of formalin-fixed paraffin wax-embedded tissues that had been stored for 18 years. viral antigen was detected in crypt epithelial cells of the tonsil, collecting tubula ...	1999	10486165
diva vaccines that reduce virus transmission.	this brief review deals with the effect of diva (differentiating infected from vaccinated individuals) vaccines (also termed marker vaccines) on transmission of herpesviruses and pestiviruses in swine and cattle. pseudorabies and bovine herpesvirus 1 diva vaccines have been demonstrated to reduce transmission of wild-type virus in populations of pigs and cattle in the laboratory as well as in the field. a subunit diva vaccine based on the immunodominant e2 protein of classical swine fever virus ...	1999	10486928
genetic diversity of pestiviruses: identification of novel groups and implications for classification.	the complete npro coding sequences were determined for 16 pestiviruses isolated from cattle, pig, and several wild ruminant species including reindeer, bison, deer, and bongo. phylogenetic analysis enabled the segregation of pestiviruses into the established species bovine viral diarrhea virus-1 (bvdv-1), bvdv-2, border disease virus (bdv), and classical swine fever virus (csfv). for bvdv-1 five distinct subgroups were identified, while bvdv-2, bdv, and csfv were each subdivided into two subgrou ...	1999	10489341
molecular epidemiology of classical swine fever in cuba.	the origin and evolution of the classical swine fever (csf) epizootic that occurred in cuba from 1993 to 1997 has been investigated by the analysis of e2 gene sequences from 15 representative viral isolates as well as the vaccine and the challenge strains used in this country. in the phylogenetic tree derived from these sequences, the cuban isolates were located in a defined cluster within the previously reported genomic subgroup 1.2. this cluster was related, although distinguishable, from the ...	1999	10500283
experimental infection of slaughter pigs with classical swine fever virus: transmission of the virus, course of the disease and antibody response.	the spread of classical swine fever virus was investigated in an isolation unit containing four pens, each containing six slaughter pigs. one pig in the middle pen of three adjacent pens was inoculated intramuscularly and intranasally with the virus. the fourth pen was located in a separate compartment. the pens were visited in a strict order to study, first, the effect of indirect contact via contaminated clothing and footwear on the spread of the virus to adjacent pens and, secondly, the airbo ...	1999	10504066
african swine fever virus dutpase is a highly specific enzyme required for efficient replication in swine macrophages.	the african swine fever virus (asfv) gene e165r, which is homologous to dutpases, has been characterized. a multiple alignment of dutpases showed the conservation in asfv dutpase of the motifs that define this protein family. a biochemical analysis of the purified recombinant enzyme showed that the virus dutpase is a trimeric, highly specific enzyme that requires a divalent cation for activity. the enzyme is most probably complexed with mg(2+), the preferred cation, and has an apparent k(m) for ...	1999	10515998
does porcine reproductive and respiratory syndrome virus potentiate classical swine fever virus infection in weaner pigs?	fifteen 6-week-old crossbred weaners weighing about 12 kg each were randomly divided into three groups of five animals each. one group of pigs was inoculated first with porcine reproductive and respiratory syndrome (prrs) virus and then 3 days later with csf virus. the second group received classical swine fever (csf) virus, while the third group was inoculated with prrs virus only. the aim of the experiment was to determine whether a primary prrs virus infection influences the clinical outcome ...	1999	10528545
intermediate stages in monocyte-macrophage differentiation modulate phenotype and susceptibility to virus infection.	the kinetics of monocyte-macrophage differentiation was analysed using two swine workshop cluster (swc) cd molecules: swc1 and swc9. myeloid cells were selected by labelling for the common myeloid antigen, swc3. confirmation of macrophage identification used acid phosphatase and phagocytosis activities. during differentiation, swc1 was gradually lost. swc9 was absent on monocytes but up-regulated early. consequently, monocytes were swc1+ swc9- and macrophages were swc1- swc9+. an additional, int ...	1999	10540219
recovery and assay of african swine fever and swine vesicular disease viruses from pig slurry.	assaying samples for infectious virus is more difficult when the sample is toxic to cells used in the assay, e.g. with samples of infected pig slurry. various techniques were compared for the recovery of african swine fever virus (asfv) and swine vesicular disease virus (svdv) in pig slurry. extraction with freon led to 80-100% recovery of svdv added to pig slurry. the assay sensitivity enabled undiluted, centrifuged sample to be put directly onto monolayers of ib-rs2 cells, allowing a minimum d ...	1999	10540248
classical swine fever virus is genetically stable in vitro and in vivo.	phylogenetic analyses of large numbers of classical swine fever strains have revealed a high degree of sequence conservation in the genomic regions examined, suggesting either a recent common ancestor or a low evolution rate. this low variability is in contrast to findings with other rna viruses. to investigate the consequence of this apparent genetic stability on phylogenetic examinations, the belgian field isolate wingene'93 was passaged in pigs as well as in cell culture by various methods. s ...	1999	10542017
differentiation between vaccine strain and field isolates of classical swine fever virus using polymerase chain reaction and restriction test.	the cs vaccine strain of classical swine fever virus is a derivative from the lk parental strain that has been used in russia for more than 30 years. a 10697 nucleotide fragment of the cs strain's genome has been sequenced. sixteen unique restriction markers have been found in the cs genome comparing to the following strains: alfort187, alfort tubingen, brescia, cap, glentorf, ald, gpe-, chinese, c-strain, riems, p97. fourteen of these sites (aflii, avai, cfoi, eco47ii, haeii, kpni, muni, nspi, ...	1999	10547932
mutations abrogating the rnase activity in glycoprotein e(rns) of the pestivirus classical swine fever virus lead to virus attenuation.	classical swine fever (csf) is a severe hemorrhagic disease of swine caused by the pestivirus csf virus (csfv). amino acid exchanges or deletions introduced by site-directed mutagenesis into the putative active site of the rnase residing in the glycoprotein e(rns) of csfv abolished the enzymatic activity of this protein, as demonstrated with an rnase test suitable for detection of the enzymatic activity in crude cell extracts. incorporation of the altered sequences into an infectious csfv clone ...	1999	10559339
csiro's 'natural' vaccines.		1999	10561787