Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| [immunohistochemical studies on organ tropism of different biotypes of bvd virus in experimentally infected sheep fetuses]. | paraffin sections from various organs of sheep fetuses following transplacental infection with non-cytopathogenic (ncp) bovine viral diarrhoea virus (bvdv) or cytopathogenic (cp) bvdv were stained immunohistochemically with bvdv-specific monoclonal antibodies. comparison of the distribution of viral antigen in sections from fetuses of experiment a revealed that in organs such as parotid, thyroid, thymus, lung, spleen, kidney, liver and skin from 20 days post inoculation (p.i.) onwards numerous a ... | 1997 | 9445784 |
| cytotoxic t-lymphocyte responses in cattle infected with bovine viral diarrhea virus. | a system for a reproducible in vitro restimulation of bovine viral diarrhea virus (bvdv)-specific cytotoxic t-cells (ctl) was developed. lymphocyte cultures of bvdv-immunised cattle were stimulated with infectious bvdv isolate pt810 and recombinant bovine interleukin-2 for 12 to 25 days. a specific lysis of concanavalin a-stimulated bvdv-infected autologous target cells was observed, whereas allogeneic bvdv-infected target cells were only marginally lysed as detected by flow cytometry. bvdv-spec ... | 1997 | 9451457 |
| an improved elisa for the detection of serum antibodies directed against classical swine fever virus. | the complex-trapping-blocking (ctb) elisa for detection of antibodies against classical swine fever virus (csfv) using two monoclonal antibodies (mabs) directed against envelope glycoprotein e2, has been improved using recombinant csfv e2-antigen. the newly developed ceditest elisa for csfv-ab is a modification of the ctb-elisa as described by wensvoort et al. (1988) and bloemraad et al. (1993). the old ctb-elisa format comprised of a two-step, single-dilution test which had to be performed by h ... | 1997 | 9460193 |
| evidence for biotype-specific effects of bovine viral diarrhoea virus on biological responses in acutely infected calves. | the relationship between the two biotypes of bovine viral diarrhoea virus (bvdv) and the biological responses they induce was studied in 3- to 6-month-old calves inoculated intranasally with a homologous pair of non-cytopathic and cytopathic strains. marked differences in virological and serological events occurred following exposure to a specific bvdv strain. the non-cytopathic biotype was frequently recovered from nasal secretions and blood cells during the first 28 days post-inoculation where ... | 1998 | 9460918 |
| diagnostic studies of abortion in danish dairy herds. | diagnostic findings in 218 aborted bovine foetuses are reported. the materials were examined in a matched case-control study of 69 danish dairy herds with a sudden increase in the number of abortions and a corresponding 69 control herds. foetuses aborted during the subsequent 6-month period were examined to identify the cause of abortion if possible. a total of 186 specimens were submitted from case herds and 32 from control herds. a likely cause of abortion was diagnosed in 73 foetuses. the mos ... | 1997 | 9465775 |
| level of viral antigen in blood leucocytes from cattle acutely infected with bovine viral diarrhoea virus. | blood samples from 24 calves undergoing experimental acute infection with a non-cytopathogenic bovine viral diarrhoea virus (bvdv) were examined for viral antigen in peripheral leucocytes with an enzyme-linked immunosorbent assay (elisa), and for presence of virus in blood plasma in a cell culture assay. with the antigen elisa, low positive values were detected in leucocytes sampled on days 3-4 from two of eight animals inoculated intranasally, and on days 11-13 from three of 16 animals inoculat ... | 1997 | 9467300 |
| characterization of a bovine viral diarrhea virus isolated from roe deer in germany. | the 5' untranslated region (5' utr) of cytopathogenic pestiviruses isolated from two seronegative roe deer (capreolus capreolus) in northern germany was partially sequenced and compared with those of 28 other pestiviruses. due to the occurrence within a narrow location and the complete identity of the sequenced fragments from both roe deer isolates (sh9 and sh11) they seem to belong to the same bovine virus diarrhea virus (bvdv) strain called sh9/11. this strain is highly homologous (up to 93% i ... | 1998 | 9476225 |
| serologic evidence of bovine viral diarrhea virus in free-ranging rabbits from germany. | from 1993 to 1995, 100 blood samples and 97 spleen samples of free-ranging rabbits (oryctolagus cuniculus) from northern germany were tested for prevalence of different bovine viral diarrhea virus (bvdv) antibodies and bvdv antigen, respectively. forty sera (40%) were positive for antibodies to one or more of three cytopathogenic bvdv strains (nadl, grub 313/83, and roe deer isolate sh9/11). microneutralization test (nt) titers ranged from 5 to 13. moreover, 13 of 35 nt positive sera also were p ... | 1998 | 9476243 |
| comparison of rt-pcr assay and virus isolation in cell cultures for the detection of bovine viral diarrhoea virus (bvdv) in field samples. | the virus isolation-immunoperoxidase test (ipx) on cell cultures and the reverse transcription-polymerase chain reaction (rt-pcr) assay were compared for the detection of bovine viral diarrhoea virus (bvdv) directly in serum samples. material for this study consisted of 403 sera originating from cattle in 41 bvdv-infected finnish dairy herds and one suckler cow herd. the presence of virus was demonstrated in 48 samples by both assays. in addition, two more samples were found to be positive by th ... | 1997 | 9491443 |
| genetic heterogeneity of bovine viral diarrhoea viruses isolated in southern africa. | seventy three field isolates of bovine viral diarrhoea virus (bvdv), obtained from cattle in mozambique and south africa, were characterised by comparative nucleotide sequence analysis of part of the 5' non-coding region (5'ncr) of the viral genome. the target region was amplified by reverse transcription-polymerase chain reaction (rt-pcr). the amplicons were cloned in puc 19 plasmid and both strands were sequenced by t7 polymerase dideoxynucleotide chain-termination sequencing or directly by cy ... | 1997 | 9495536 |
| identification of bovine viral diarrhea virus nonstructural polypeptide ns4b/p38. | the bovine pestivirus polyprotein is processed into at least 11 mature polypeptides. previous studies with polyprotein region-specific antiserum raised against beta-galactosidase fusion proteins or synthetic peptides allowed the assignment of viral non-structural proteins to specific segments of the bvdv genome. however, the gene product from the ns4b/p38 region of the viral genome remained to be demonstrated directly. bvdv cdna fragments predicted to encode part of ns4b/p38 (from codon 2521 to ... | 1997 | 9498617 |
| characterization of an autonomous subgenomic pestivirus rna replicon. | as an initial approach to define the requirements for the replication of bovine viral diarrhea virus (bvdv), a member of the flaviviridae family with a positive-strand rna genome, full-length genomic and subgenomic rnas were originated by in vitro transcription of diverse bvdv cdna constructs and transfected into eucaryotic host cells. rna replication was measured either directly by an rnase protection method or by monitoring the synthesis of viral protein. when full-length bvdv crna was initial ... | 1998 | 9499097 |
| [cytopathogenic bovine viral diarrhea viruses induce apoptosis in bovine cell cultures]. | the pestivirus bovine viral diarrhea (bvd) virus is the causative agent of mucosal disease (md) of cattle. from persistently infected animals, only the non-cytopathogenic biotype bvd virus can be isolated. cattle succumbing to md additionally harbour cytopathogenic bvd virus. while cp bvd virus isolates induce a cytopathic effect (cpe) in susceptible monolayer cell cultures, infection with ncp bvd virus isolates has no visible effect. the purpose of this study was to investigate the correlation ... | 1998 | 9499630 |
| evaluation of bovine viral diarrhea virus control using a mathematical model of infection dynamics. | a mathematical model for infection with bovine viral diarrhea virus (bvdv) was created comprising a series of coupled differential equations. the model architecture is a development of the traditional model framework using susceptible, infectious and removed animals (the sir model). the model predicts 1.2% persistent infection (within the range of field estimates) and is fairly insensitive to alterations of structure or parameter values. this model allows us to draw important conclusions regardi ... | 1998 | 9500167 |
| detection of bvdv in bovine embryos derived from persistently infected heifers by pcr. | 1998 | 9501387 | |
| experimental mucosal disease of cattle: changes in cell proliferation in lymphoid tissues and intestinal epithelium. | in mucosal disease of cattle, the initial and most severe lesions are found in the lymphoid follicles and intestinal crypts, both sites showing a high cell proliferation rate. in the present study, the changes in the number and distribution of proliferating cells were investigated immunohistologically, by demonstrating the proliferation-associated nuclear antigen, ki-67. tissues were obtained from 30 cattle, all of which had a persistent natural infection with non-cytopathogenic (ncp) bovine vir ... | 1997 | 9502270 |
| a new assay for classical swine fever virus based on cytopathogenicity in porcine kidney cell line fs-l3. | a new assay termed the dome disappearance method for classical swine fever virus (csfv) using fs-l3 cells with serum-free culture medium was developed. the csfv live vaccine gpe- strain grows well and shows a slight cytopathic effect (cpe) in fs-l3 cells. this cpe results in the disappearance of the unique fluid-filled multicellular domes on a single monolayer of fs-l3 cells. by using this phenomenon, dome disappearance, as a marker of infection, it was possible to determine the titers of csfv a ... | 1998 | 9506817 |
| replication of cytopathic and noncytopathic bovine viral diarrhea virus in zona-free and zona-intact in vitro-produced bovine embryos and the effect on embryo quality. | the aim of the present study was to determine whether or not cytopathic (cp) and noncytopathic (ncp) bovine viral diarrhea virus (bvdv) are able to replicate within in vitro-produced embryos and to investigate whether inoculation of embryos with bvdv affects their normal development. zona pellucida (zp)-free oocytes, zygotes, 8-cell-stage embryos, morulae, and hatched blastocysts (hb) were incubated for 1 h in 1 ml of minimal essential medium containing 10(6.00) tissue culture infectious dose (t ... | 1998 | 9510977 |
| changes in levels of viremia in cattle persistently infected with bovine viral diarrhea virus. | virus isolation and serum neutralizing antibody titers were determined over a period of time from samples collected from animals persistently infected with bovine viral diarrhea virus (bvdv). to evaluate over time the ability to detect bvdv by virus isolation from serum or white blood cell preparations, 4 persistently infected calves were monitored from birth until 70 days of age. in 3 of 4 persistently infected calves, virus isolation from serum and white blood cells was negative until approxim ... | 1998 | 9526856 |
| severe acute bovine viral diarrhea in ontario, 1993-1995. | in 1993, noncytopathic bovine viral diarrhea virus (bvdv) strains with enhanced virulence caused unprecedented outbreaks of severe acute bovine viral diarrhea (bvd) in dairy, beef, and veal herds in ontario (canada). fever, pneumonia, diarrhea, and sudden death occurred in all age groups of cattle. abortions often occurred in pregnant animals. gross lesions in the alimentary tract were similar to those associated with mucosal disease, especially in animals >6 months of age. cattle of all age gro ... | 1998 | 9526857 |
| evaluation of a single dilution elisa system for detection of seroconversion to bovine viral diarrhea virus, bovine respiratory syncytial virus, parainfluenza-3 virus, and infectious bovine rhinotracheitis virus: comparison with testing by virus neutralization and hemagglutination inhibition. | a single-dilution quantitative enzyme-linked immunosorbent assay (elisa) system, based on commercial elisa kits, for the simultaneous detection of seroconversion to bovine viral diarrhea virus (bvdv), bovine respiratory syncytial virus (brsv), parainfluenza-3 virus (pi3v), and infectious bovine rhinotracheitis virus (ibrv) was evaluated by testing acute and convalescent serum pairs from 564 cattle in 145 outbreaks of respiratory disease. seroconversion to bvdv, brsv, pi3v and ibrv was detected i ... | 1998 | 9526859 |
| the replicative intermediate molecule of bovine viral diarrhoea virus contains multiple nascent strands. | the replication of bovine viral diarrhoea virus (bvdv) rna is considered to involve replicative intermediates (ri) and replicative forms (rf) of virus rna. these rna species were radiolabelled metabolically by 3h-uridine in bvdv-infected cells and separated by sucrose gradient centrifugation. rna in the fractions was then digested with rnase a in high salt (2 x ssc) and the rnase-resistance was determined. using the baltimore formula, this led to the calculation that the ri of bvdv contained 6-7 ... | 1998 | 9541623 |
| a monoclonal antibody-based immunoperoxidase monolayer (micro-isolation) assay for detection of type 1 and type 2 bovine viral diarrhea viruses. | a monoclonal antibody (mab)-based immunoperoxidase monolayer assay (ipma) for detection of bovine viral diarrhea virus (bvdv) was developed and compared with an existing bovine polyclonal antibody (pab)-based ipma. a pool of 5 mabs, 4 mabs produced to a type 1 bvdv and 1 mab produced to a type 2 bvdv, was utilized in the mab-ipma. the mabs were chosen for inclusion in the pool because of their broad cross-reactivities with type 1 and/or type 2 bvdv, their apparent avidities for antigen, their re ... | 1998 | 9553717 |
| expression of a 50 kda putative receptor for bovine viral diarrhea virus in bovine fetal tissues. | the expression of a 50 kda bovine viral diarrhea virus putative receptor in different bovine fetal tissues from 3-month old fetuses was studied. the receptor expression was examined by immunocytochemical staining and by immunoblotting using antiidiotypic probe (anti-d89). intense specific staining in enterocytes of the small and large intestines, cortical tubular epithelial cells of kidneys, respiratory epithelial cells of the trachea and esophageal mucosal epithelial cells was observed, demonst ... | 1998 | 9553718 |
| transport of viruses through fetal membranes: an in vitro model of perinatal transmission. | a model system for perinatal transmission of viral infections was developed and transport of infectious virus particles through fetal membranes was investigated. viruses of different families known to cause serious intrauterine infections were selected, including relevant and model viruses: the dna-viruses hsv-1 and -2 as well as the animal herpes viruses bhv-1 and shv-1, the rna-virus bvdv as a model for hepatitis c virus, hiv-1 and -2, and ppv as a model for parvovirus b19. migration of infect ... | 1998 | 9557298 |
| bovine viral diarrhea virus strain oregon: a novel mechanism for processing of ns2-3 based on point mutations. | bovine viral diarrhea virus (bvdv) isolates can either be cytopathogenic (cp) or noncytopathogenic (noncp). while both biotypes express the nonstructural protein ns2-3, generation of ns3 strictly correlates with the cp phenotype. the production of ns3 is usually caused by cp specific genome alterations, which were found to be due to rna recombination. molecular analyses of the cp bvdv strain oregon revealed that it does not possess such genome alterations but nevertheless is able to generate ns3 ... | 1998 | 9557702 |
| insertion of a sequence encoding light chain 3 of microtubule-associated proteins 1a and 1b in a pestivirus genome: connection with virus cytopathogenicity and induction of lethal disease in cattle. | pestiviruses represent the first rna viruses for which recombination with cellular protein-coding sequences has been reported. as a result of such recombinations cytopathogenic (cp) pestiviruses can develop from noncytopathogenic (noncp) viruses. in the case of bovine viral diarrhea virus (bvdv), the generation of cp mutants is linked to the induction of the lethal syndrome mucosal disease (md) in cattle. the cp bvdv jacp was isolated from an animal which had come down with md. the genome of jac ... | 1998 | 9557703 |
| a novel method for pestivirus genotyping based on palindromic nucleotide substitutions in the 5'-untranslated region. | a simple and practical method was developed for pestivirus genotyping based on analysis of the secondary structures in the 5'-untranslated region (utr). three stable stem-loop structures, v1, v2 and v3, predicted by computer in the 5'-utr, included strictly conserved consensus base-pairings which are shared by all the genotypes of pestivirus or are characteristic to each genotype of pestivirus. on the basis of the palindromic nucleotide substitution at the secondary structural level, six genotyp ... | 1998 | 9562417 |
| infectious bovine viral diarrhea virus (strain nadl) rna from stable cdna clones: a cellular insert determines ns3 production and viral cytopathogenicity. | bovine viral diarrhea virus (bvdv), strain nadl, was originally isolated from an animal with fatal mucosal disease. this isolate is cytopathic in cell culture and produces two forms of ns3-containing proteins: uncleaved ns2-3 and mature ns3. for bvdv nadl, the production of ns3, a characteristic of cytopathic bvdv strains, is believed to be a consequence of an in-frame insertion of a 270-nucleotide cellular mrna sequence (called cins) in the ns2 coding region. in this study, we constructed a sta ... | 1998 | 9573238 |
| complete genomic sequence of border disease virus, a pestivirus from sheep. | the genus pestivirus of the family flaviviridae comprises three established species, namely, bovine viral diarrhea virus (bvdv), classical swine fever virus (csfv), and border disease virus from sheep (bdv). in this study, we report the first complete nucleotide sequence of bdv, that of strain x818. the genome is 12,333 nucleotides long and contains one long open reading frame encoding 3, 895 amino acids. the 5' noncoding region (ncr) of bdv x818 consists of 372 nucleotides and is thus similar i ... | 1998 | 9573288 |
| detection of bovine viral diarrhea virus in the ovaries of cattle acutely infected with bovine viral diarrhea virus. | bovine viral diarrhea virus (bvdv) is recognized worldwide as a major cause of economic loss in cattle. infection with bvdv can result in several clinical outcomes. however, the reproductive consequences may be the most important. infertility, early embryonic death, abortion, and congenital anomalies have all been reported following acute infection with bvdv. the cause of infertility following acute bvdv infection is not known. bvdv has been isolated from the bovine ovary and has been associated ... | 1998 | 9576337 |
| detection of cytopathic bovine viral diarrhea virus in the ovaries of cattle following immunization with a modified live bovine viral diarrhea virus vaccine. | economic loss from infection with bovine viral diarrhea virus (bvdv) is of worldwide concern. the unique pathogenesis and antigenic variability of bvdv have made this virus challenging to control. vaccination programs are a major component of control and prevention strategies. both killed and modified live vaccines are commercially available. choice between killed and modified live vaccines is controversial. of major concern is the safety of modified live vaccines. little information is availabl ... | 1998 | 9576338 |
| prevalence of bovine viral diarrhea virus genotypes and antibody against those viral genotypes in fetal bovine serum. | one thousand lots of pooled fetal bovine serum (fbs) were tested for contamination with bovine viral diarrhea virus (bvdv) and/or for contamination with neutralizing antibody against bvdv. noncytopathic or cytopathic bvdv was isolated from 203 lots of fbs. analysis of the viral isolates identified 115 type 1 and 65 type 2 bvdv isolates. an additional 23 virus isolates were mixtures of > or = 2 bvdv isolates and were not classified to viral genotype. further characterization of the type 1 viruses ... | 1998 | 9576339 |
| distribution of antibody titers to bovine viral diarrhea virus in infected, exposed, and uninfected beef cattle. | 1998 | 9576349 | |
| prevalence of antibodies to bovine virus diarrhoea virus and other viruses in bulk tank milk in england and wales. | bulk tank milk samples from 1070 dairy herds in england and wales were tested by elisa for antibodies to bovine virus diarrhoea virus (bvdv). a subset of 341 herds was tested by elisa for antibodies to bovine herpesvirus 1 (bhv-1), bovine respiratory syncytial virus (brsv) and bovine coronavirus (bcv). none of the herds had less than 40 dairy cows and none had been vaccinated against bvdv. the prevalence of bvdv antibody-positive herds in the national population was estimated at 95 per cent and ... | 1998 | 9586130 |
| the duration of antibodies against bovine virus diarrhoea virus in bulk milk. | fifty-eight dairy herds, suspected to be recently infected with bovine virus diarrhoea virus (bvdv) due to a rise in bvdv antibodies in bulk milk, were followed over a two-year period. in 34 (59%) of these 58 herds (group 1), pooled milk samples from heifers or pooled blood samples from calves were negative for bvdv antibodies. in this group as many as 53 and 76% of the herds again had antibody-negative bulk milk one and two years after the positive sample, respectively. of the remaining herds, ... | 1998 | 9592949 |
| the effect of bovine virus diarrhoea virus on reproduction in recently infected norwegian dairy herds. | a group of 32 dairy herds, recently infected with bovine virus diarrhoea virus (bvdv), was compared with a control group consisting of 75 bvdv free herds during a 3-year-period. variables related to reproduction were registered. results of multiple antibody examinations in bulk milk as well as samples of milk and blood from younger animals were used to select the herds. the incidence of abortions was statistically significantly different in the 2 groups, while the number of stillbirths, weak bor ... | 1998 | 9592950 |
| mapping of a type 1-specific and a type-common epitope on the e2 (gp53) protein of bovine viral diarrhea virus with neutralization escape mutants. | bovine viral diarrhoea viruses (bvdv) have recently been segregated into two genotypes, bvdv 1 and bvdv 2. however, the antigenic differences and similarities of bvdv 1 and bvdv 2 remain poorly defined. in this study, the e2 epitopes of two neutralizing monoclonal antibodies (mabs) produced against an isolate of bvdv 1 were mapped. the mab 157, previously determined to be broadly cross-reactive to bvdv, was discovered to be bvdv 1-specific, whereas mab 348 bound to and neutralized bvdv 2. both m ... | 1998 | 9617771 |
| the immune response of cattle, persistently infected with noncytopathic bvdv, after superinfection with antigenically semi-homologous cytopathic bvdv. | cattle persistently infected (pi) with noncytopathic (ncp) bovine virus diarrhea virus (bvdv) are at risk for developing fatal mucosal disease (md), which is considered to occur after superinfection with antigenically homologous cytopathic (cp) bvdv. in this study, we intranasally inoculated four pi-animals, that were pi with 2 ncp bvdv strains with 10(5) tcid50 antigenically closely related cp bvdv. two pi-animals were inoculated with 10(5) tcid50 ncp bvdv and one pi-animal, with virus free cel ... | 1998 | 9618867 |
| [pestivirus as causative agent of abortion and perinatal mortality in cattle and sheep in switzerland]. | the causal involvement of bovine viral diarrhoea virus (bvdv) and border disease virus (bdv) infection in bovine and ovine abortion and perinatal mortality remain unclear. from 1992 until 1994, 213 bovine and 31 ovine foetuses as well as 36 calves and 25 lambs which had died perinatally were investigated. tissue samples were tested for the presence of pestiviruses and serum or fluid from the body cavities were analysed for the presence of pestivirus antibodies. detection of pestiviruses was perf ... | 1998 | 9618985 |
| the ns5a/ns5 proteins of viruses from three genera of the family flaviviridae are phosphorylated by associated serine/threonine kinases. | phosphorylation of the expressed ns5a protein of hepatitis c virus (hcv), a member of the hepacivirus genus of the family flaviviridae, has been demonstrated in mammalian cells and in a cell-free assay by an associated kinase activity. in this report, phosphorylation is also shown for the ns5a and ns5 proteins, respectively, of bovine viral diarrhea virus (bvdv) and yellow fever virus (yf), members of the other two established genera in this family. phosphorylation of bvdv ns5a and yf ns5 was ob ... | 1998 | 9621090 |
| a novel nested reverse transcription pcr detects bovine viral diarrhoea virus in fluids from aborted bovine fetuses. | a nested reverse transcription-pcr (rt-pcr) was developed to detect pestivirus nucleic acid in fetal fluids and to study the number of bovine abortions associated with bvdv infection. three techniques for the extraction of viral rna from fetal fluids were compared; phenol:chloroform method, treatment with catrimox-14 followed by guanidium isothiocyanate buffer and the qiagen total rna kit. the qiagen kit was the most sensitive and reproducible and therefore adopted. after cdna synthesis, initial ... | 1998 | 9628223 |
| persistent bovine pestivirus infection localized in the testes of an immuno-competent, non-viraemic bull. | a post-pubertal bull on an artificial insemination station was found to be persistently shedding bovine viral diarrhoea virus (bvdv) in semen over a period of eleven months, while demonstrating no viraemia. circulating antibodies to bvdv were consistently high, suggesting that the immune system was challenged repeatedly. post-mortem findings confirmed that the virus was sequestered in the testes of the bull. it is hypothesized that the bvdv in this immuno-competent bull was protected from the bu ... | 1998 | 9631528 |
| persistently infected cattle stabilise bovine viral diarrhea virus leading to herd specific strains. | animals persistently infected with bvdv are important in the epizootiology of the bovine viral diarrhea (bvd) because they are a permanent source of contamination within a herd. these animals produce large quantities of virus and have, therefore, been proposed as responsible for generating antigenic variability. however, limited studies have failed to detect antigenic or genetic changes in viruses isolated at different time from persistently infected animals. one hypothesis to account for this s ... | 1998 | 9631529 |
| differentiation of types 1a, 1b and 2 bovine viral diarrhoea virus (bvdv) by pcr. | there are two genotypes among bovine viral diarrhoea viruses (bvdv), bvdv1 and bvdv2. within the bvdv1 genotype there are two distinct subgenotypes, bvd1a and bvd1b. serology and monoclonal antibody binding are used to differentiate bvdv from classical swine fever virus (csfv) and border disease virus (bdv), the other members of the pestivirus genus. these techniques are less useful in the differentiation and segregation of viruses within the bvdv species. in this study, differential polymerase ... | 1998 | 9633045 |
| bovine viral diarrhea virus replication in bovine follicular epithelial cells derived from persistently infected heifers. | bovine follicle fluid and oocytes surrounded by follicular epithelial (fe) cells were collected from ovaries of two heifers persistently infected with bovine viral diarrhea virus (bvdv). bvdv was present in the follicle fluid at a higher titer than in serum. the oocytes were matured in vitro under culture conditions of 39 degrees c in humidified air containing 5% co2. in vitro fertilization was performed after 24 hr in culture (the day of insemination was defined as day 1), and culture was conti ... | 1998 | 9637289 |
| segregation of bovine viral diarrhea virus isolated in japan into genotypes. | it was suggested that 3 strains of bovine viral diarrhea virus (bvdv) isolated from persistently infected calves in tochigi prefecture in japan belonged to bvdv type ii. it was recognized lack of psti site on the 5'-untranslated region of genome of them as well as bvdv type ii reported previously. inoculated with the 3 strains, the calves showed the mild decrease of platelet counts which was specific clinical sign of bvdv type ii. we should report that the 3 strains were the first bvdv type ii i ... | 1998 | 9637291 |
| experimental induction of mucosal disease: consequences of superinfection of persistently infected cattle with different strains of cytopathogenic bovine viral diarrhea virus. | mucosal disease (md) can be induced in cattle persistently infected with noncytopathogenic bovine viral diarrhea virus (ncp bvd virus) by superinfecting them with antigenically related cytopathogenic (cp) bvd virus strains. while some of these animals succumb to early onset md after 2 to 3 weeks post infectionem (p.i.), others only react by producing neutralizing antibodies against the cp bvd virus strain and may develop late onset md after longer incubation periods. the aim of this study was to ... | 1998 | 9638140 |
| nucleotide sequence homology to bovine viral diarrhea virus 2 (bvdv 2) in the 5' untranslated region of bvdvs from cattle with mucosal disease or persistent infection in japan. | cytopathogenic and non-cytopathogenic bovine viral diarrhea viruses (bvdvs) were isolated from cattle with mucosal disease or persistent infection in japan. these isolates were compared for antigenic properties by cross-neutralization tests with japanese reference strains of bvdv belonging to classical type 1. significantly low cross-reactivity to reference strains was noted, indicating the viruses to possibly represent a new serotype in japan. thus, to determine the genotype of the isolates, nu ... | 1998 | 9646457 |
| [clinical-virologic course after superinfection of persistently infected cattle with cytopathogenic bovine viral diarrhea virus strains]. | vaccination with live cytopathogenic (cp) bovine viral diarrhoea virus (bvdv) is often used for control of this disease. in animals which are persistently infected with noncytopathogenic (ncp) bvdv this can lead to the outbreak of mucosal disease (md). to simulate vaccination of such animals and to monitor the clinical-virological course after superinfection, nine clinically healthy calves which were persistently viremic were superinfected with different cp bvdv strains. one animal succumbed to ... | 1998 | 9646556 |
| genome instability in bvdv: an examination of the sequence and structural influences on rna recombination. | the cytopathogenic biotype of the pestivirus, bovine viral diarrhea virus, is frequently a product of nonhomologous recombination in the region of the genome encoding the viral ns2-ns3 proteins. the possibility that sequences or structures in this region contributed to a hotspot for rna recombination was examined. a pcr-based strategy was used to examine viral genomic rna isolated from tissue samples of cattle persistently infected with the noncytopathogenic biotype of the virus. analysis of two ... | 1998 | 9657953 |
| specificity and duration of neutralizing antibodies induced in healthy cattle after administration of a modified-live virus vaccine against bovine viral diarrhea. | to determine the duration for cross-neutralizing antibodies stimulated by administration of a single dose of a modified-live vaccine against bovine viral diarrhea virus (bvdv) to seronegative cattle. | 1998 | 9659549 |
| organ and tissue distribution of the antigen of the cytopathogenic bovine virus diarrhea virus in the early and advanced phase of experimental mucosal disease. | to study the development of lesions in mucosal disease, the spread of cytopathogenic (cp) bovine virus diarrhea virus (bvdv) to different organs was examined in relation to the time post inoculation (pi). mucosal disease was induced in 15 persistently viremic cattle from two herds by intranasal inoculation with antigenically similar cp bvdv strain. this strain reacted with one additional monoclonal antibody when compared to the corresponding herd-specific non cytopathogenic (ncp) isolate. twelve ... | 1997 | 9672623 |
| experimental infection with babesia divergens in cattle persistently infected with bovine virus diarrhoea virus. | nine norwegian red cattle, aged 7-14 months, persistently infected with bovine virus diarrhoea virus (bvdv) were inoculated with a swedish strain of babesia divergens. six persistently infected cattle of the same age and breed were kept as controls. blood and serum samples were collected regularly during the observation period. rectal temperatures were recorded every morning for 25 days post infection, and the animals were examined clinically on a daily basis. sera were examined for antibodies t ... | 1998 | 9673578 |
| alpha-glucosidase inhibitors as potential broad based anti-viral agents. | n-linked oligosaccharides play many roles in the fate and functions of glycoproteins. one function is to assist in the folding of proteins by mediating interactions of the lectin-like chaperone proteins calnexin and calreticulin with nascent glycoproteins. these interactions can be prevented by inhibitors of the alpha-glucosidases and this causes some proteins to be misfolded and retained within the endoplasmic reticulum. in human immunodeficiency virus (hiv) and hepatitis b virus (hbv) the misf ... | 1998 | 9678587 |
| bovine viral diarrhoea virus induces apoptosis in blood mononuclear cells by a mechanism largely dependent on monocytes. | the induction of apoptosis by bovine viral diarrhoea virus (bvdv) was examined in bovine peripheral blood mononuclear cells (pbmc) incubated with an antigenically homologous pair of non-cytopathic and cytopathic bvdv. our results show that the cytopathic biotype, in contrast to the non-cytopathic counterpart, induces apoptosis in pbmc. flow cytometry analysis of cells undergoing apoptosis revealed that: (1) monocytes constitute the major cell population undergoing apoptosis; (2) cytopathic virus ... | 1998 | 9680138 |
| lesions and distribution of viral antigen following an experimental infection of young seronegative calves with virulent bovine virus diarrhea virus-type ii. | during the past several years, acute infections with bovine viral diarrhea virus (bvdv) have been causally linked to hemorrhagic and acute mucosal disease-like syndromes with high mortality. the majority of bvdvs isolated in such cases have been classified as type ii on the basis of genetic and antigenic characteristics. it was our objective to examine clinical disease, lesions and potential sites of viral replication, following experimental bvdv type ii infection in young calves. on approximate ... | 1998 | 9684044 |
| immunohistochemical evidence for the localization of bovine viral diarrhea virus, a single-stranded rna virus, in ovarian oocytes in the cow. | bovine viral diarrhea virus (bvdv) is a single-stranded rna virus responsible for enteric disease and reproductive failure in cattle. the virus can pass vertically from cow to fetus, causing abortion, birth of malformed calves, and calves born with persistent and life-long infections. in this study, we investigated the tropism of bvdv in ovarian tissue from persistently infected animals. three heifers persistently infected with bvdv were euthanatized and their ovaries were recovered. a specimen ... | 1998 | 9684968 |
| border disease of sheep and goats. | border disease (bd) is a congenital virus disease of sheep and goats first reported in 1959 from the border region of england and wales. bd virus (bdv) is a pestivirus in the genus flaviviridae and is closely related to classical swine fever virus and bovine virus diarrhoea virus (bvdv). nearly all isolates of bdv are non-cytopathogenic (ncp) in cell culture. there are no defined serotypes but pestiviruses isolated from sheep exhibit considerable antigenic diversity and three distinct antigenic ... | 1998 | 9689745 |
| epidemiologic herd-level assessment of causative agents and risk factors for winter dysentery in dairy cattle. | to test the association between exposure to bovine coronavirus (bcv) and outbreaks of winter dysentery (wd) in dairy herds and to examine other risk factors for outbreaks of wd in dairy herds. | 1998 | 9706203 |
| detection of bovine viral diarrhea virus (bvdv) using reverse transcription polymerase chain reaction assay. | the reverse transcription polymerase chain reaction (rt-pcr) was applied to detect bovine viral diarrhea virus (bvdv) for the rapid diagnosis. the primers were selected from the p80 region of bvdv gene. the rt-pcr assay detected all of the 17 bvdv strains tested including cytopathogenic and non-cytopathogenic strains, while specific amplification was not observed from 17 bovine viruses other than bvdv. detection limit of the assay was 10(1.5) tcid50/ml. sera and organ samples were collected from ... | 1998 | 9713819 |
| critical factors affecting the diagnostic reliability of enzyme-linked immunosorbent assay formats. | this paper aims to evaluate different formats of the enzyme-linked immunosorbent assays (elisas) for detection of virus-specific antibodies and focuses on factors that may influence the diagnostic reliability of such tests. newly developed and well-established elisas for detection of infections of bovine herpesvirus 1 (bhv1), bovine respiratory syncytial virus (brsv), classical swine fever virus (csfv), pseudorabies virus (prv) and bovine viral diarrhoea virus (bvdv) are used as examples. differ ... | 1998 | 9713894 |
| prevalence of antibodies to bovine viral diarrhoea virus and/or border disease virus in domestic ruminants. | a total of 62 sera collected from cattle, buffalo, sheep, goats and camels were investigated for the presence of antibodies to bovine viral diarrhoea (bvd) virus. the prevalence of neutralizing antibodies to bvd virus was 49.2, 52.0, 27.5, 31.4 and 52.5% in cattle, buffalo, sheep, goats and camels, respectively. the positive sera were titrated against bvd virus (bvdv) strains nadl and oregon c24v; the latter is closely related to border disease (bd) virus. the frequency distributions of the anti ... | 1998 | 9719767 |
| long-term viral serology of semi-free-living and captive ungulates. | between 1973 and 1994, blood samples were collected at whipsnade wild animal park (uk) from three ungulate species kept in enclosures, including 28 european bison (bison bonasus), 37 scimitar-horned oryx (oryx dammah), and 49 père david's deer (elaphurus davidianus), and also from 144 semi-free-living chinese water deer (hydropotes inermis). these samples were tested for the presence of antibodies against three bovine viral diarrhea virus (bvdv)-like strains, three alpha-herpesvirus strains, enz ... | 1998 | 9732031 |
| pathogenesis of mucosal disease, a deadly disease of cattle caused by a pestivirus. | two biotypes of pestiviruses, cytopathogenic (cp) and non-cytopathogenic (noncp) viruses, are distinguished by their effects on tissue culture cells. in contrast to the bovine viral diarrhoea virus (bvdv) system, only a few cp border disease virus (bdv) and cp classical swine fever virus (csfv) strains have been described. antigenically closely related noncp and cp bvdv can be isolated from cattle with fatal mucosal disease (md) and are called a virus pair. the generation of cp bvdv in an animal ... | 1998 | 9741637 |
| maternal recognition of foetal infection with bovine virus diarrhoea virus (bvdv)--the bovine pestivirus. | pestiviruses are the veterinary viruses with genome homology to human hepatitis c virus (hcv). this group includes classical swine fever virus (csfv), border disease virus of sheep (bdv) and bovine virus diarrhoea virus (bvdv). there are some similarities in the pathology of all three virus infections; in utero transmission to the foetus can cause early embryonic losses, severe congenital abnormalities and, particularly with bvdv, lifelong persistent infections. in situ hybridisation studies hav ... | 1998 | 9741639 |
| influence of concurrent bvdv infection on the igm response of calves experimentally infected with bovine respiratory syncytial virus. | 1998 | 9762762 | |
| ribosomal s27a coding sequences upstream of ubiquitin coding sequences in the genome of a pestivirus. | molecular characterization of cytopathogenic (cp) bovine viral diarrhea virus (bvdv) strain cp rit, a temperature-sensitive strain widely used for vaccination, revealed that the viral genomic rna is about 15.2 kb long, which is about 2.9 kb longer than the one of noncytopathogenic (noncp) bvdv strains. molecular cloning and nucleotide sequencing of parts of the genome resulted in the identification of a duplication of the genomic region encoding nonstructural proteins ns3, ns4a, and part of ns4b ... | 1998 | 9765411 |
| identification and characterization of an rna-dependent rna polymerase activity within the nonstructural protein 5b region of bovine viral diarrhea virus. | nonstructural protein 5b (ns5b) of bovine viral diarrhea virus (bvdv) contains sequence motifs that are predictive of an rna-dependent rna polymerase activity. we describe the expression and purification of the bvdv ns5b protein derived from an infectious cdna clone of bvdv (nadl strain). bvdv ns5b protein was active in an in vitro rna polymerase assay using homopolymeric rna or bvdv minigenomic rna templates. the major product was a covalently linked double-stranded molecule generated by a "cop ... | 1998 | 9765490 |
| virulence markers in the 5' untranslated region of genotype 2 bovine viral diarrhea virus isolates. | virulence markers to distinguish high from low virulence bovine viral diarrhea virus genotype 2 isolates have not been previously reported. the objective of this study was to identify virulence markers by evaluating the primary and secondary structures of the 5'-untranslated region of low and high virulence bovine viral diarrhea virus genotype 2 isolates. the nucleotide sequences of the entire 5'-untranslated region mrna of eight bovine viral diarrhea virus genotype 2 isolates, four of high viru ... | 1998 | 9770430 |
| an rt-pcr assay for the specific detection of classical swine fever virus in clinical samples. | a simple reverse transcriptase-polymerase chain reaction (rt-pcr) assay has been developed for the specific amplification of dna after reverse transcription of rna from the classical swine fever virus (csfv). a pair of oligonucleotides was selected from an area of high homology in the genome of csfv strains, but which differed from the corresponding sequences in the genome of bovine viral diarrhea virus (bvdv) strains. using these primers (csfv1-csfv2), a csfv specific dna band of 174 bp was amp ... | 1998 | 9779556 |
| an experimental study of a concurrent primary infection with bovine respiratory syncytial virus (brsv) and bovine viral diarrhoea virus (bvdv) in calves. | experimental infections with bovine respiratory syncytial virus (brsv) and bovine viral diarrhoea virus (bvdv) were performed to study the effect of concurrent brsv and bvdv infections. twelve seronegative calves, in 3 groups, were inoculated on a single occasion with pure brsv (group a), brsv and noncytopathogenic bvdv (group b) or mock infected (group c). mild respiratory symptoms were recorded 4 to 5 days post inoculation (dpi) in group a and group b calves. one calf in group a was severely a ... | 1998 | 9787488 |
| [the occurrence of bvd virus infections in lower austrian dairy farms]. | bulk tank milk samples from 5,024 dairy herds in lower austria were tested by elisa for antibodies to bovine virus diarrhoea virus (bvdv). approximately 54 per cent of the herds had a low level of bulk tank antibody unsuspected of recent infection with bvdv. in 512 herds, which had a high level of bulk tank antibody suggestive of recent infection with bvdv, milk samples from 5-10 primiparous cows, respectively were tested by elisa for antibodies to bvdv. in 287 (56.1%) of these 512 herds only an ... | 1998 | 9793236 |
| evaluation of the suitability of a commercial bovine viral diarrhoea virus antigen capture elisa for diagnostic testing. | the suitability of a commercial bovine viral diarrhoea virus (bvdv) antigen capture enzyme-linked immunosorbent assay (elisa) for routine diagnostic testing of bovine serum samples was evaluated by comparing the elisa results of 214 sera with those obtained after two passages in roller tube cultures of fetal bovine lung cells and immunofluorescent staining using fluorescein isothiocyanate-conjugated hyperimmune bvdv anti-serum. in addition, 208 of these samples were tested by virus isolation in ... | 1998 | 9805483 |
| acute pulmonary lesions in sheep experimentally infected with bovine viral diarrhoea virus. | six sheep, aged 6-8 months and seronegative for pestivirus, were inoculated intranasally, through the tracheal wall, and intrabronchially with a non-cytopathogenic isolate of bovine viral diarrhoea virus (ncpbvdv). infected sheep were killed in pairs on post-inoculation day (pid) 2, 4 and 6. they all exhibited transient leucopenia or lymphopenia, or both. platelet counts decreased but remained within normal limits. bvdv was isolated from buffy coats and tissues of all sheep inoculated with ncpbv ... | 1998 | 9807729 |
| clinical and immunologic responses of vaccinated and unvaccinated calves to infection with a virulent type-ii isolate of bovine viral diarrhea virus. | to determine efficacy of a modified-live type-i isolate of bovine viral diarrhea virus (bvdv) vaccine in protecting calves from infection with a virulent type-ii isolate, and to determine which type of immune response (i.e., humoral or cellular) correlates with protection. | 1998 | 9810390 |
| inactivation of viruses by beta-propiolactone in human cryo poor plasma and igg concentrates. | virus inactivation by cold treatment with beta-propiolactone (bpl) was investigated in human cryo poor plasma and purified igg concentrates spiked with relevant human viruses or appropriate animal model viruses. the samples were treated with 0.1 or 0.25% bpl for 300 or 480 min, respectively. residual infectivity was determined by standard microtitration assays on tissue culture cells. the inactivation of all viruses tested was more effective in igg than in plasma. igg: r1=4-5.5 log10 for vesicul ... | 1998 | 9811521 |
| cis-acting rna elements required for replication of bovine viral diarrhea virus-hepatitis c virus 5' nontranslated region chimeras. | pestiviruses, such as bovine viral diarrhea virus (bvdv), share many similarities with hepatitis c virus (hcv) yet are more amenable to virologic and genetic analysis. for both bvdv and hcv, translation is initiated via an internal ribosome entry site (ires). besides ires function, the viral 5' nontranslated regions (ntrs) may also contain cis-acting rna elements important for viral replication. a series of chimeric rnas were used to examine the function of the bvdv 5' ntr. our results show that ... | 1998 | 9814762 |
| protection of pregnant cattle and their fetuses against infection with bovine viral diarrhea virus type 1 by use of a modified-live virus vaccine. | to determine efficacy of a vaccine containing modified-live bovine viral diarrhea virus (bvdv) type 1 for protecting pregnant cows and their fetuses against virulent heterologous bvdv type 1. | 1998 | 9829398 |
| effect of concurrent experimentally induced bovine respiratory syncytial virus and bovine viral diarrhea virus infection on respiratory tract and enteric diseases in calves. | to compare experimentally induced concurrent bovine viral diarrhea virus (bvdv) and bovine respiratory syncytial virus (brsv) infection with single virus infection. | 1998 | 9829401 |
| insertion of a bovine smt3b gene in ns4b and duplication of ns3 in a bovine viral diarrhea virus genome correlate with the cytopathogenicity of the virus. | bovine viral diarrhea virus (bvdv) infection in cattle can lead to the development of a fatal syndrome called mucosal disease (md). the induction of md requires co-existence of two biotypes of bvdv: cytopathic (cp) and non-cytopathic (ncp). studies have shown that in some cases, cp viruses are generated from ncp viruses by cellular gene insertions, duplications or rearrangements in the viral genome. cellular ubiquitin gene is the most frequently reported insert in bvdv 1. here we report the find ... | 1998 | 9833880 |
| genetic analysis of the internal ribosome entry segment of bovine viral diarrhea virus. | pestiviruses and hepaciviruses are atypical members of the flaviviridae due to their unique biological properties, including the utilization of internal ribosome entry for translation initiation. in contrast to internal initiation in picornaviruses, which depends on numerous canonical initiation factors, the mode of internal ribosome entry in pestiviruses and hepaciviruses resembles prokaryotic translation initiation. to identify functionally important elements within the bovine viral diarrhea v ... | 1998 | 9837801 |
| validation of the heat treatment step used in the production of diaspirin crosslinked hemoglobin (dclhb) for viral inactivation. | a series of experiments was performed to assess the ability of the heat treatment step used in the manufacture of diaspirin crosslinked hemoglobin (dclhb) to inactivate viruses. in-process solutions (reaction mixtures after the crosslinking process) from six different manufacturing lots were used as test media in a 1:680 scaled down system in which the key process parameters used in the large scale production were duplicated. the inactivation of five different viruses (bovine viral diarrhea viru ... | 1998 | 9844723 |
| use of polymerase chain reaction to simultaneously detect and type bovine viral diarrhoea viruses isolated from clinical specimens. | the techniques of indirect immunofluorescence (if), immuno-peroxidase (ip) staining and the one-step reverse transcriptase polymerase chain reaction (rt-pcr) were compared for detection of 102 isolates of bovine viral diarrhoea virus (bvdv) in infected cell cultures. the bvdv was obtained from bovine clinical specimens, including sera, buffy coats and tissues, submitted from farms located in the states of iowa and wisconsin, united states of america. the if technique detected 88/102 (86.3%) of t ... | 1998 | 9850544 |
| detection of antibodies to bovine viral diarrhoea virus (bvdv) and characterization of genomes of bvdv from brazil. | an elisa for the detection of antibodies to bovine viral diarrhea virus (bvdv) was developed based on antigens derived from a genotype i bvdv strain isolated in switzerland. using monoclonal antibodies we showed that this antigen contained the conserved non-structural protein ns3 whereas it essentially lacked the more strain-specific e2 surface glycoprotein. this elisa has a sensitivity of 97.5% and a specificity of 99.2% as compared to the serum neutralization test (snt). preliminary experiment ... | 1998 | 9850989 |
| a stable cell line with a proportion of cells persistently infected with bovine viral diarrhoea virus. | bovine turbinate (btu) and lamb testis (lt) cell lines persistently infected with bovine viral diarrhoea virus (bvdv) arose as a result of a single change of medium containing commercial foetal calf serum. infected cells comprise 30% and 50% respectively, of the total cell population, determined by immunohistochemical staining. the ratio of positive cells has remained unchanged during successive passages. characterization of the persistently-infected btu cells (btui) showed that only full length ... | 1998 | 9850992 |
| monoclonal antibodies to the e2 protein of a new genotype (type 2) of bovine viral diarrhea virus define three antigenic domains involved in neutralization. | bovine viral diarrhea virus (bvdv) has recently been segregated into two genotypes, namely, bvdv 1 and bvdv 2. viruses of the bvdv 2 genotype are a cause of hemorrhagic and acute fatal disease in cattle in the us and canada. in this study, monoclonal antibodies (mabs) to the newly described bvdv 2 were produced after immunization with virus or a combination of virus and e2 peptide. from an original panel of 17 mabs, 13 mabs were identified as e2-specific by reactivity with a bvdv 2 recombinant e ... | 1998 | 9870585 |
| prolonged nasal shedding and viraemia of cytopathogenic bovine virus diarrhoea virus in experimental late-onset mucosal disease. | a calf persistently infected with bovine virus diarrhoea virus (bvdv) was super-infected with a heterologous bvdv strain, c874, which contained non-cytopathogenic and cytopathogenic viruses. high titres of cytopathogenic bvdv were recovered in the three to four weeks after the challenge. thereafter low titres of cytopathogenic virus were recovered repeatedly from the blood and the nose, with the titres in nasal secretions increasing in the four weeks before the onset of clinical signs. neutralis ... | 1998 | 9871955 |
| new methods for inactivation of lipid-enveloped and non-enveloped viruses. | two new methods are described for inactivating lipid-enveloped and non-enveloped viruses in plasma-derived products such as coagulation factors and intravenous immunoglobulin (igiv). iodine/sephadex delivers iodine to igiv solutions in a slow, controlled way and allows for inactivation of > or = 4 logs of porcine parvovirus (ppv), a hardy non-enveloped virus, under conditions which do not measurably damage the structural or functional properties of the igiv, and with essentially no iodination of ... | 1998 | 9873761 |
| distribution of bovine virus diarrhoea virus in tissues and white blood cells of cattle during acute infection. | this study is performed to gain knowledge about the quantitative distribution of bovine virus diarrhoea virus (bvdv) in tissues and white blood cells (wbc) at different intervals after acute infection. ten specific pathogen-free calves were intranasally inoculated with 10(5) 50% tissue culture infective dose of the non-cytopathic bvdv strain 4800. twelve hours after inoculation tonsil biopsies were taken and wbc were collected daily for virus isolation and titration. each day one calf was killed ... | 1998 | 9874100 |
| anti-viral effect of interferon-alpha on bovine viral diarrhea virus. | to get basic information to control persistent virus infection among domestic animals by cytokines, the antiviral activity of four natural human cytokines against bovine viral diarrhea virus (bvdv) was evaluated. normal bovine peripheral blood mononuclear leukocytes (pbml) and fetal bovine muscular cells (fbmc) were treated with varying doses of human interferon (ifn)-alpha, ifn-gamma, tumor necrosis factor (tnf)-alpha and tnf-beta. the antiviral activity in treated cells was measured by the tit ... | 1998 | 9879534 |
| de novo initiation of rna synthesis by a recombinant flaviviridae rna-dependent rna polymerase. | recombinant rna-dependent rna polymerases have been reported to synthesize rnas by extending from the 3' hydroxyl of a template or an oligonucleotide primer. de novo initiation has not been reported. establishment of such an assay would facilitate the analysis of the initiation requirements and allow the testing of antiviral compounds specifically targeting initiation. using chemically synthesized rnas and dnas, we demonstrate that the recombinant rna-dependent rna polymerase (ns5b) of bovine vi ... | 1999 | 9887312 |
| synergistic effects of bovine respiratory syncytial virus and non-cytopathic bovine viral diarrhea virus infection on selected bovine alveolar macrophage functions. | the effect of bovine respiratory syncytial virus (brsv) and non-cytopathic bovine viral diarrhea virus (ncpbvdv) infection on selected bovine alveolar macrophage (am) functions was investigated. alveolar macrophages were harvested from 2- to 6-month-old calves seronegative for brsv and bvdv and inoculated with approximately 1 median cell culture infective dose of virus per am. control, brsv infected, ncpbvdv-infected and brsv-ncpbvdv coinfected am cultures were evaluated for fc receptor expressi ... | 1999 | 9918333 |
| seroepidemiology of undifferentiated fever in feedlot calves in western canada. | the relationships between 4 bacterial and 3 viral antibody titers and morbidity (undifferentiated fever (uf)) and mortality were investigated in recently weaned beef calves. blood samples from 100 animals that required treatment for uf (cases) and 100 healthy control animals (controls) were obtained: upon arrival at the feedlot (arrival), at the time of selection as a case or control (selection), and at approximately 33 d of the feeding period (convalescent). seroconversion to pasteurella haemol ... | 1999 | 9919366 |
| antigenic characterization of brazilian bovine viral diarrhea virus isolates by monoclonal antibodies and cross-neutralization. | nineteen brazilian isolates of bovine viral diarrhea virus (bvdv) were characterized antigenically with a panel of 19 monoclonal antibodies (mabs) (corapi wv, donis ro and dubovi ej (1990) american journal of veterinary research, 55: 1388-1394). eight isolates were further characterized by cross-neutralization using sheep monospecific antisera. analysis of mab binding to viral antigens by indirect immunofluorescence revealed distinct patterns of reactivity among the native viruses. local isolate ... | 1998 | 9921280 |
| sensitivity comparison for detection of respiratory bovine coronaviruses in nasal samples from feedlot cattle by elisa and isolation with the g clone of hrt-18 cells. | a monoclonal antibody-based capture enzyme-linked immunosorbent assay (elisa) was developed to detect respiratory bovine coronavirus (rbcv) antigens in nasal swabs collected from cattle showing signs of respiratory tract disease following shipping. these samples had been previously tested for rbcv by inoculation of g clone cultures of human rectal tumor cells (hrt-18g) and for bovine herpes virus 1, parainfluenza virus 3, bovine adenovirus, bovine respiratory syncytial virus, and bovine viral di ... | 1999 | 9925206 |
| phylogenetic evidence for the improved rna higher-order structure in internal ribosome entry sequences of hcv and pestiviruses. | the strong requirement for a small segment of the 5'-proximal coding sequence of hepatitis c virus (hcv) is one of the most remarkable features in the internal initiation of hcv mrna translation. phylogenetic analysis and rna folding indicate a common rna structure of the 5' untranslated region (utr) of hcv and the animal pestiviruses, including hcv types 1-11, bovine viral diarrhea (bvdv), border disease virus (bdv) and hog cholera (hocv). although the common rna structure shares similar featur ... | 1998 | 9926403 |
| prevalence of bovine virus diarrhoea virus infection in belgian white blue cattle in southern belgium. | a study was conducted in southern belgium to determine the prevalence of bovine viral diarrhoea virus (bvdv) infection in belgian white blue herds. blood samples were taken from 9685 cattle, representing all the stock on 61 farms, by local veterinarians to screen for persistently infected animals and to determine their serological status against bvdv. some of the herds (42.5%) were selected because of a prior positive diagnosis of bvdv or on the grounds of suspicion of bvd. a capture enzyme-link ... | 1999 | 9990704 |
| epidemiological features and economical importance of bovine virus diarrhoea virus (bvdv) infections. | infections with bovine virus diarrhoea virus (bvdv) are widespread throughout the world. although the prevalence of infection varies among surveys, the infection tends to be endemic in many populations, reaching a maximum level of 1-2% of the cattle being persistently infected (pi) and 60-85% of the cattle being antibody positive. persistently infected cattle are the main source for transmission of the virus. however, acutely infected cattle as well as other ruminants, either acutely or persiste ... | 1999 | 10028165 |
| distribution of viral antigen in uterus, placenta and foetus of cattle persistently infected with bovine virus diarrhoea virus. | the tissue distribution and cellular localisation of bovine virus diarrhoea virus (bvdv) was investigated in the uterus, placentomes, intercotyledonary foetal membranes and foetal organs of three persistently infected (pi) pregnant heifers. the uterus and ovaries of a non-pregnant pi heifer were also included in the study. cryostat sections were examined using immunohistochemical techniques and monoclonal antibodies against bvdv. a double immunofluorescence technique was used to identify bvdv po ... | 1999 | 10028166 |