| pilot scale thermal treatment of pig slurry for the inactivation of animal virus pathogens. | this paper describes a pilot scale treatment plant that has been designed and built for the thermal inactivation in pig slurry of two viruses that infect pigs--african swine fever virus (asfv) and swine vesicular disease virus (svdv). the plant treats pig slurry continuously at a rate of up to 100 litres/hour and functions by heating the slurry, maintaining at least 99.99% of the slurry at the required temperature for a minimum period of 5 minutes, and then recovering the heat to raise the tempe ... | 1999 | 10565423 |
| the rna-dependent rna polymerases of different members of the family flaviviridae exhibit similar properties in vitro. | the virus-encoded rna-dependent rna polymerase (rdrp), which is required for replication of the positive-strand rna genome, is a key enzyme of members of the virus family flaviviridae. by using heterologously expressed proteins, we demonstrate that the 77 kda ns5b protein of two pestiviruses, bovine viral diarrhoea virus and classical swine fever virus, and the 100 kda ns5 protein of the west nile flavivirus possess rdrp activity in vitro. as originally shown for the rdrp of hepatitis c virus, r ... | 1999 | 10573150 |
| an african swine fever virus orf with similarity to c-type lectins is non-essential for growth in swine macrophages in vitro and for virus virulence in domestic swine. | an african swine fever virus (asfv) orf, 8cr, with similarity to the c-type lectin family of adhesion proteins has been described in the pathogenic isolate malawi lil-20/1. the similarity of 8cr to cellular and poxvirus genes associated with cell adhesion, cell recognition and virus infectivity suggested that 8cr may be of significance to asfv-host cell interactions. sequence analysis of the 8cr orf from additional pathogenic asfv isolates demonstrated conservation among isolates from both pig a ... | 1999 | 10573162 |
| the effectiveness of routine serological surveillance: case study of the 1997 epidemic of classical swine fever in the netherlands. | the authors describe the value of routine serological surveillance in detecting the introduction of classical swine fever virus into a disease-free population. the first investigation concerned the question of whether the epidemic of classical swine fever (csf), which occurred from 1997 to 1998 in the netherlands, could have been detected using the existing monitoring system for notifiable diseases. the investigation used data from the csf epidemic of 1997/1998 and from the existing monitoring s ... | 1999 | 10588006 |
| classical swine fever: the european experience and a guide for infected areas. | classical swine fever (csf) (hog cholera) virus infection is still of world-wide concern, either because of the direct effects of the disease on swine breeding in areas where the virus is epizootic or enzootic, or as a threat in areas where the virus has been eradicated. the authors provide an overview of the characteristics of the disease. special emphasis is placed on the chronic form of disease, particularly in the late stages of eradication programmes. in the early 1980s, the european union ... | 1999 | 10588007 |
| in vitro inhibition of the replication of haemorrhagic septicaemia virus (vhsv) and african swine fever virus (asfv) by extracts from marine microalgae. | we have screened for in vitro inhibition of viral replication with extracts from the following marine microalgae: porphyridium cruentum, phaeodactylum tricornutum, tetraselmis suecica, chlorella autotrophica, dunaliella tertiolecta, dunaliella bardawil, isochrysis galbana, isochrysis galbana var tiso, ellipsoidon sp. and tetraselmis tetrathele. we have used as viral models two enveloped viruses of significant economic importance, the viral hemorrhagic septicemia virus (vhsv) of salmonid fish and ... | 1999 | 10588334 |
| vaccination with a single dose of a recombinant porcine adenovirus expressing the classical swine fever virus gp55 (e2) gene protects pigs against classical swine fever. | a recombinant porcine adenovirus (rpav) with the gp55 (e2) gene from the classical swine fever virus (csfv) 'weybridge' strain inserted into the right hand end of the pav serotype 3 (pav3) genome was constructed. expression of gp55 was directed by the major late promoter and tri-partite leader sequences located and cloned from pav3. no compensatory deletions of pav dna sequences were made. vaccination of outbred pigs with a single dose of the recombinant virus (rpav-gp55) resulted in complete pr ... | 2000 | 10590324 |
| phylogenetic comparison and molecular epidemiology of classical swine fever virus. | the genetic diversity of classical swine fever virus (csfv) was studied by rt-pcr amplification and sequencing of a 409 bp fragment of the ns5b polymerase region. a total of 106 viruses isolated from 20 countries over a period of 52 years (1945-1997) were included in the phylogenetic study. the results showed that the viruses could be divided into two main groups. group 1 consisted of asian and south american isolates from the 1980s, as well as of old european and american isolates. group 2 cons ... | 1999 | 10595410 |
| classical swine fever virus in plasma and peripheral blood mononuclear cells of acutely infected swine. | the distribution of classical swine fever virus (csfv) in plasma, monocytes, t and b lymphocytes in peripheral blood was monitored during experimentally induced acute classical swine fever infection in piglets. six piglets were infected with 10(3.8) tcid50 of virus and blood samples taken up to 18 days post-inoculation (p.i.). infectious virus was detected in monocytes, t and b lymphocytes to similar titres in five of the six infected piglets. infectious virus was detected earlier in plasma than ... | 1999 | 10605368 |
| determination of the onset of the herd-immunity induced by the e2 sub-unit vaccine against classical swine fever virus. | for a recently developed e2 subunit vaccine against classical swine fever (csf), the reduction in transmission, at different moments after vaccination, was assessed by animal experiments and statistical calculations. two experiments were performed to estimate the reproduction ratio r. experiment 1 consisted of three groups and experiment 2 of two groups each of 10 pigs. in four of these groups, all pigs were vaccinated intramuscularly with the vaccine. the pigs in the fifth group remained unvacc ... | 2000 | 10618535 |
| laboratory decision-making during the classical swine fever epidemic of 1997-1998 in the netherlands. | the national reference laboratory for classical swine fever (csf) virus in the netherlands examined more than two million samples for csf virus or serum antibody during the csf epizootic of 1997-1998. the immense amount of samples and the prevalence of border disease (bd) virus and bovine viral diarrhoea (bvd) virus infections in dutch pig herds necessitated the diagnostic efforts of the laboratory to be focused on generating csf specific test results throughout the eradication campaign. detecti ... | 1999 | 10619155 |
| transmission of classical swine fever virus within herds during the 1997-1998 epidemic in the netherlands. | in this paper, we describe the transmission of classical swine fever virus (csf virus) within herds during the 1997-1998 epidemic in the netherlands. in seven herds where the infection started among individually housed breeding stock, all breeding pigs had been tested for antibodies to csf virus shortly before depopulation. based upon these data, the transmission of csf virus between pigs was described as exponential growth in time with a parameter r, that was estimated at 0.108 (95% confidence ... | 1999 | 10619156 |
| quantification of the transmission of classical swine fever virus between herds during the 1997-1998 epidemic in the netherlands. | in this study, we describe a method to quantify the transmission of classical swine fever virus (csfv) between herds from data collected during the 1997-1998 epidemic in the netherlands. from the contacts between infected herds and the serological findings shortly before depopulation, we estimated the week of virus introduction and the length of the period over which the herd emitted virus for each csfv-infected herd. from these data, we estimated the infection-rate parameter beta (the average n ... | 1999 | 10619157 |
| the 1997-1998 classical swine fever epidemic in the netherlands--a survival analysis. | the aim of this analysis was to characterise the temporal pattern of infection during the 1997/98 classical swine fever (csf) epidemic in the netherlands and hence identify and quantify risk factors for infection in different enterprise types and areas. survival analysis and cox proportional hazards regression were used to describe the epidemic. substantial differences in temporal survival patterns (herd breakdown rate) were found between areas where different control policies operated. factors ... | 1999 | 10619158 |
| spatial and stochastic simulation to evaluate the impact of events and control measures on the 1997-1998 classical swine fever epidemic in the netherlands. ii. comparison of control strategies. | using the spatial, temporal and stochastic simulation model intercsf, several alternative pre-emptive slaughter strategies that could have been applied in the dutch classical swine fever (csf) epidemic of 1997-1998 were evaluated. furthermore, effects of changes in some disease-spread and disease-control parameters were studied. intercsf simulates the spread of csf between farms through local spread and contacts (animals, transport and persons). disease spread is affected by control measures imp ... | 1999 | 10619161 |
| an african swine fever virus erv1-alr homologue, 9gl, affects virion maturation and viral growth in macrophages and viral virulence in swine. | the african swine fever virus (asfv) genome contains a gene, 9gl, with similarity to yeast erv1 and alr genes. erv1 has been shown to function in oxidative phosphorylation and in cell growth, while alr has hepatotrophic activity. 9gl encodes a protein of 119 amino acids and was highly conserved at both nucleotide and amino acid levels among all asfv field isolates examined. monospecific rabbit polyclonal antibody produced to a glutathione s-transferase-9gl fusion protein specifically immunopreci ... | 2000 | 10627538 |
| regulation of calcineurin by growth cone calcium waves controls neurite extension. | growth cones generate spontaneous transient elevations of intracellular ca(2+) that regulate the rate of neurite outgrowth. here we report that these ca(2+) waves inhibit neurite extension via the ca(2+)-dependent phosphatase calcineurin (cn) in xenopus spinal neurons. pharmacological blockers of cn (cyclosporin a and deltamethrin) and peptide inhibitors of cn [the xenopus cn (xcn) autoinhibitory domain and african swine fever virus protein a238l] block the ca(2+)-dependent reduction of neurite ... | 2000 | 10627609 |
| african swine fever virus ep153r open reading frame encodes a glycoprotein involved in the hemadsorption of infected cells. | the open reading frame ep153r, located within the ecori e' fragment of the african swine fever (asf) virus genome, is predicted to encode a membrane protein of 153 amino acids that presents significant homology to the n-terminal region of several cd44 molecules. ep153r contains multiple putative sites for n-glycosylation, phosphorylation, and myristoylation, a central transmembrane region, a c-type animal lectin-like domain, and a cell attachment sequence. transcription of ep153r takes place at ... | 2000 | 10639320 |
| characterization of the african swine fever virus protein p49: a new late structural polypeptide. | the open reading frame b438l, located within the ecori b fragment of the african swine fever virus genome, is predicted to encode a protein of 438 amino acids with a molecular mass of 49.3 kda. it presents a cell attachment rgd (arg-gly-asp) motif but no other significant similarity to protein sequences in databases. northern blot and primer extension analysis showed that b438l is transcribed only at late times during virus infection. the b438l gene product has been expressed in escherichia coli ... | 2000 | 10640542 |
| observations on the quasispecies composition of three animal pathogenic rna viruses. | the quasispecies nature of three animal pathogenic rna viruses of field origin was examined by testing variants of classical swine fever virus (csfv) originating from geographically different areas, feline coronavirus (fcov) detected from the same animal by successive sampling, and rabbit haemorrhagic disease virus (rhdv) originating from successive outbreaks in the same geographic area. clinical samples were investigated using reverse transcriptase polymerase chain reaction (rt-pcr) and ensuing ... | 1999 | 10641337 |
| infections with flaviviridae. | the family of the flaviviridae contains 3 genera: (i) the hepaciviruses, to which belongs hepatitis c virus (hcv), (ii) the flaviviruses and (iii) the pestiviruses. over 140 million people, more than four times the number of hiv-positive individuals, are chronically infected with the hcv. hepatitis g virus (hgv) has not yet been assigned to a genus. the impact of this recently discovered virus is yet to be established. infections with flaviviruses such as yellow fever virus (yfv), dengue fever v ... | 1999 | 10655776 |
| 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 |
| 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 |
| african swine fever virus protease, a new viral member of the sumo-1-specific protease family. | african swine fever virus (asfv) is a complex dna virus that employs polyprotein processing at gly-gly-xaa sites as a strategy to produce several major core components of the viral particle. the virus gene s273r encodes a 31-kda protein that contains a "core domain" with the conserved catalytic residues characteristic of sumo-1-specific proteases and the adenovirus protease. using a cos cell expression system, it was found that protein ps273r is capable of cleaving the viral polyproteins pp62 an ... | 2001 | 11031264 |
| origins of the csf outbreak. | | 2000 | 11037735 |
| molecular epidemiology of a large classical swine fever epidemic in the european union in 1997-1998. | a big epidemic of classical swine fever (csf) occurred in the european community in 1997. the first case was reported at the beginning of january 1997 from germany. the disease presumably spread to the netherlands, and from there to italy, spain and eventually to belgium. about 30 isolates from these outbreaks were analysed by comparison of the nucleotide sequence data generated from fragments of both the e2 glycoprotein gene (190 nucleotides) and from the 5'-nontranslated region (5'-ntr; 150 nu ... | 2000 | 11042397 |
| epidemiology of classical swine fever in germany in the 1990s. | in germany, 424 outbreaks of csf in domestic pigs and a great number of cases in wild boar were recorded between 1990 and 1998. most of the federal states ('bundesländer') were affected. epidemiological data from field investigations combined with genetic typing allowed to distinguish seven unrelated epidemics and a number of sporadic outbreaks in domestic pigs. detailed epidemiological data was available for 327 outbreaks. it was found that 28% of these were primary outbreaks. most of them were ... | 2000 | 11042398 |
| a serological survey on classical swine fever (csf), aujeszky's disease (ad) and porcine reproductive and respiratory syndrome (prrs) virus infections in french wild boars from 1991 to 1998. | in early 1992, a csf epizootic was clinically recognised in a wild boar population of approximately 1300 animals within an area of 250km(2) located in the east of france. in order to check the csf situation in wild boars outside this area, a serological survey was carried out in the rest of france, for 8 consecutive years (1991-1998). this paper reports on the results obtained during this survey which included wild boars shot during the hunting period but also boars reared within fences. around ... | 2000 | 11042399 |
| genetic typing of classical swine fever virus isolates from the territory of the czech republic. | epizootiological studies based on genetic typing were performed using 14 isolates from outbreaks of classical swine fever (csf) in domestic pigs and wild boar in the czech republic which occurred between 1991 and 1998. they were compared with austrian, slovakian, hungarian, polish and german isolates. the aim of this study was to characterise the csf virus isolates and find out the possible relationships between the outbreaks in domestic pigs and wild boar, and to map the spread of the virus in ... | 2000 | 11042400 |
| classical swine fever virus: a second ring test to evaluate rt-pcr detection methods. | six laboratories participated in a study to compare the sensitivity and specificity of rt-pcr tests for the detection of classical swine fever virus (csfv). sets of coded samples were prepared by serial dilution of positive samples and then distributed to each of the laboratories. one set comprised 25 samples of random primed cdna, synthesised from viral rna representative of different pestiviruses. the other set comprised samples of blood and serum obtained from virus-free or csfv-infected pigs ... | 2000 | 11042401 |
| efficacy of the classical swine fever (csf) marker vaccine porcilis pesti in pregnant sows. | the efficacy of the classical swine fever (csf) subunit marker vaccine porcilis pesti based on baculovirus expressed envelope glycoprotein e2 of csf virus (csfv) was evaluated in pregnant sows. ten gilts were vaccinated with one dose of marker vaccine, followed by a second dose 4 weeks later. four gilts remained unvaccinated and received a placebo at the same times. thirty-three days after the second vaccination all animals were artificially inseminated. neither local or systemic reactions nor a ... | 2000 | 11042402 |
| safety and efficacy of a classical swine fever subunit vaccine in pregnant sows and their offspring. | in the study three groups with five pregnant sows each were used. the animals were vaccinated twice, 2 weeks apart, in different stages of gestation, i.e. +/-4, +/-8 and +/-12 weeks after insemination and then 14 days later, respectively. from each group of sows three litters were randomly selected and vaccinated twice, 4 weeks apart, at 5 and 9, 7 and 11, and 9 and 13 weeks of life, respectively. blood for serological investigations by virus neutralisation test and elisa tests (for e(rns) antib ... | 2000 | 11042403 |
| detection of classical swine fever virus in semen of infected boars. | during the classical swine fever (csf) epidemic in 1997 in the eu member states germany, italy, spain and the netherlands, boars in an artificial insemination (ai) centre were found to be infected with csf virus. this raised a question of epidemiological importance which could not be answered immediately. can csf virus be shed by semen of infected boars and what conclusions concerning the risk of spreading csf infection by semen can be drawn. experimental studies were conducted to answer this qu ... | 2000 | 11042404 |
| the genetic basis for cytopathogenicity of pestiviruses. | two biotypes of pestiviruses, cytopathogenic (cp) and noncp viruses, can be distinguished by their effects on tissue culture cells. identification of cp bovine viral diarrhea virus (bvdv) has been frequently reported since antigenically closely related noncp and cp bvdv can be isolated from cattle with fatal mucosal disease (md) and are called a virus pair. in contrast to the bvdv system, only few cp border disease virus (bdv) and cp classical swine fever virus (csfv) strains have been described ... | 2000 | 11042405 |
| comparative immunohistopathology in pigs infected with highly virulent or less virulent strains of hog cholera virus. | eight pigs were inoculated subcutaneously with a highly virulent hog cholera virus (hcv) strain ald. the infected pigs developed severe illness and became moribund on postinoculation day (pid) 7 or pid 10. histologic lesions were characterized by severe generalized vasculitis, necrosis of lymphocytes, and encephalitis. hcv antigen was detected in crypt tonsilar epithelial cells, macrophages, and reticular endothelial cells of lymphoid tissues. antigen localization corresponded well with histolog ... | 2000 | 11055862 |
| classical swine fever: essex ban to stay in place. | | 2000 | 11083043 |
| laboratory diagnosis, epizootiology, and efficacy of marker vaccines in classical swine fever: a review. | detection of classical swine fever virus (csfv) can be achieved by a range of assays of which the most commonly used are: immunohistochemical and virus culture techniques. new developments have enabled the detection of viral proteins by enzyme-linked immunosorbent assays (elisas) and the detection of the viral genome by rt- pcr. so far, laboratory findings show that the latter assays may supplement or replace the conventional techniques in the near future. the detection of serum antibody against ... | 2000 | 11087126 |
| transmission of classical swine fever virus by artificial insemination during the 1997-1998 epidemic in the netherlands: a descriptive epidemiological study. | in the course of the 1997-1998 csf epidemic in the netherlands, two semen collection centres (scc) became infected. as an eradication strategy for an acute crisis situation, it was concluded that all semen of the boars at the sccs collected and distributed in the risk period of 28 january to 7 march 1997 was potentially contaminated (suspect semen). as a consequence, a total of 1,680 pig herds, mainly located in the southern part of the netherlands, were officially declared csf suspect. the purp ... | 2000 | 11087136 |
| deletions of structural glycoprotein e2 of classical swine fever virus strain alfort/187 resolve a linear epitope of monoclonal antibody wh303 and the minimal n-terminal domain essential for binding immunoglobulin g antibodies of a pig hyperimmune serum. | the major structural glycoprotein e2 of classical swine fever virus (csfv) is responsible for eliciting neutralizing antibodies and conferring protective immunity. the current structural model of this protein predicts its surface-exposed region at the n terminus with a short stretch of the c-terminal residues spanning the membrane envelope. in this study, the n-terminal region of 221 amino acids (aa) covering aa 690 to 910 of the csfv strain alfort/187 e2, expressed as a fusion product in escher ... | 2000 | 11090160 |
| production and characterization of monoclonal antibodies to brazilian isolates of bovine viral diarrhea virus. | three brazilian isolates of bovine viral diarrhea virus (bvdv), antigenically distinct from the standard north american isolates, were selected to immunize balb/c mice in order to obtain hybridoma cells secreting anti-bvdv monoclonal antibodies (mabs). two hybridoma clones secreting mabs, reacting specifically with bvdv-infected cells (mabs 3.1c4 and 6.f11), were selected after five fusions and screening of 1001 hypoxanthine-aminopterin-thymidine-resistant clones. these mabs reacted in an indire ... | 2000 | 11105099 |
| 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 |
| identification and characterization of a spliced c-type lectin-like gene encoded by rat cytomegalovirus. | the english isolate of rat cytomegalovirus (rcmv) encodes a 20-kda protein with a c-type lectin-like domain that is expressed in the delayed-early and late phases of the viral replication cycle. genomic sequence analysis of the restriction fragment kpnr of rcmv revealed significant homology to several c-type lectin-containing molecules implicated in natural killer (nk) and t-cell interactions, as well as genes from four poxviruses and african swine fever virus. the gene is spliced into five exon ... | 2001 | 11134273 |
| ribosomal binding to the internal ribosomal entry site of classical swine fever virus. | most eukaryotic mrnas require the cap-binding complex elf4f for efficient initiation of translation, which occurs as a result of ribosomal scanning from the capped 5' end of the mrna to the initiation codon. a few cellular and viral mrnas are translated by a cap and end-independent mechanism known as internal ribosomal entry. the internal ribosome entry site (ires) of classical swine fever virus (csfv) is approximately 330 nt long, highly structured, and mediates internal initiation of translati ... | 2000 | 11142379 |
| classical swine fever virus: clinical, virological, serological and hematological findings after infection of domestic pigs and wild boars with the field isolate "spante" originating from wild boar. | a classical swine fever virus (csfv) field isolate originating from wild boar was investigated on its virulence in domestic pigs and wild boar. three weaner pigs and two wild boars (yearlings) were intranasally inoculated with the isolate "spante" and tested for clinical, virological, hematological and serological findings until day 31 after infection (p. i.). one day p. i. the piglets were put in contact to three sentinel pigs. during a period of 31 d neither the domestic pigs nor the wild boar ... | 2000 | 11153219 |
| rna triphosphatase component of the mrna capping apparatus of paramecium bursaria chlorella virus 1. | paramecium bursaria chlorella virus 1 (pbcv-1) elicits a lytic infection of its unicellular green alga host. the 330-kbp viral genome has been sequenced, yet little is known about how viral mrnas are synthesized and processed. pbcv-1 encodes its own mrna guanylyltransferase, which catalyzes the addition of gmp to the 5' diphosphate end of rna to form a gpppn cap structure. here we report that pbcv-1 encodes a separate rna triphosphatase (rtp) that catalyzes the initial step in cap synthesis: hyd ... | 2001 | 11160672 |
| chimeric (marker) c-strain viruses induce clinical protection against virulent classical swine fever virus (csfv) and reduce transmission of csfv between vaccinated pigs. | two live recombinant vaccines (flc9 and flc11) against classical swine fever (csf) were evaluated for their capacity to reduce transmission of virulent csf virus (csfv) among vaccinated pigs. in flc9 the 5' terminal half of the e2 gene of the c-strain, a csfv vaccine strain, was exchanged with the homologous gene of the bovine viral diarrhoea virus (bvdv) strain 5250, the e(rns) gene was exchanged likewise in the chimeric flc11 virus. both recombinant vaccines induce an antibody response in pigs ... | 2001 | 11163670 |
| dna-mediated protection against classical swine fever virus. | four eukaryotic expression plasmids containing the entire e2 gene sequence of classical swine fever virus (csfv) were constructed: (a) pcdst, with 5' signal and 3' transmembrane sequences; (b) pcdsw, with 5' signal sequence only; (c) pcdwt, with transmembrane sequences only; and (d) pcdww, containing the e2 gene alone. all four plasmids were readily transfected into bhk-21 cells, with pcdst and pcdsw resulting in secretion of e2 antigen. the latter two plasmids were also shown to induce a humora ... | 2001 | 11163677 |
| development of a competitive elisa using a truncated e2 recombinant protein as antigen for detection of antibodies to classical swine fever virus. | the sequence encoding a truncated e2 glycoprotein of the alfort/187 strain of classical swine fever virus (csfv) was expressed in escherichia coli using the pet expression system and the recombinant product purified by ni-nta agarose affinity chromatography. the antigenicity of this recombinant protein was demonstrated by immunoblot using anti- csfv-specific antibodies. a monoclonal antibody was produced against the truncated e2 protein and used as competitor in an elisa for the detection of ant ... | 2001 | 11170845 |
| the non-haemadsorbing african swine fever virus isolate asfv/nh/p68 provides a model for defining the protective anti-virus immune response. | african swine fever virus asfv/nh/p68 is a naturally occurring, non-haemadsorbing and non-fatal isolate. longitudinal clinical and immunological studies on 31 pigs inoculated oronasally or intramuscularly with this isolate defined two discrete groups of animals: those developing asf chronic type lesions and those remaining asymptomatic. animals developing lesions had viraemia and fever late after infection, nk activity levels close to that of control animals and high levels of anti-asfv specific ... | 2001 | 11172092 |
| depletion of cd4(+) and cd8(high+) t-cells before the onset of viraemia during classical swine fever. | leukopenia, in particular lymphopenia, is a characteristic early event during classical swine fever (csf). this was the case in both highly virulent (csf virus (csfv) strain brescia) and moderately virulent (csfv uelzen) infections. the leukopenia involved leukocyte sub-populations in a disparate manner, with b-lymphocytes, helper t-cells and cytotoxic t-cells being the most affected. depletion of lymphocyte sub-populations occurred 1-4 days before virus could be detected by rt-pcr in the serum. ... | 2001 | 11182144 |
| duration of the protection of an e2 subunit marker vaccine against classical swine fever after a single vaccination. | the period during which pigs are protected after vaccination is important for the successful usage of a marker vaccine against classical swine fever virus (csfv) in an eradication programme. in four animal experiments with different vaccination-challenge intervals we determined the duration of protection of an e2 subunit marker vaccine in pigs after a single vaccination. unvaccinated pigs were included in each group to detect transmission of the challenge virus. three groups of six pigs were vac ... | 2001 | 11182497 |
| 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 |
| african swine fever virus iap homologue inhibits caspase activation and promotes cell survival in mammalian cells. | african swine fever virus (asfv) a224l is a member of the inhibitor of apoptosis protein (iap) family. we have investigated the antiapoptotic function of the viral iap both in stably transfected cells and in asfv-infected cells. a224l was able to substantially inhibit caspase activity and cell death induced by treatment with tumor necrosis factor alpha and cycloheximide or staurosporine when overexpressed in vero cells by gene transfection. we have also observed that asfv infection induces caspa ... | 2001 | 11222676 |