Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| comparison of the agar gel immunodiffusion test and elisa in the detection of bovine leukosis virus antibody in cattle persistently infected with bovine virus diarrhoea virus. | when six cattle persistently infected with bovine virus diarrhoea virus (bvdv) were inoculated with lymphocytes infected with bovine leukosis virus (blv), a depressed antibody response to blv was observed by elisa which was due to a decrease in igg1 synthesis. the elisa was more sensitive and more reliable than the agar gel immunodiffusion (agid) test in detecting blv infection in cattle persistently infected with bvdv. decreased antibody responses were manifested in the agid test by negative, i ... | 1989 | 2560859 |
| susceptibility of a fetal tongue cell line derived from bighorn sheep to five serotypes of bluetongue virus and its potential for the isolation of viruses. | a cell line (bhfte) was derived from a tongue explant of a bighorn sheep fetus (ovis canadensis nelsoni). the cells have been maintained through 23 serial passages, and the modal number of chromosomes was calculated to be 55. monolayer cultures were shown to be susceptible to various viruses, including bluetongue virus (btv). of 5 btv serotypes (2, 10, 11, 13, and 17) tested, each produced a cytopathic effect (cpe) on initial passage at 33 c. a field isolate (serotype 10) of btv from a black-tai ... | 1989 | 2562198 |
| detection of bovine viral diarrhea virus by spot hybridization with probes prepared from cloned cdna sequences. | a cytopathic strain of bovine viral diarrhea virus (bvdv) was purified from infected cell culture fluids by isopycnic density-gradient centrifugation. genomic rna was extracted and tailed with adenine residues at the 3' end with poly-a polymerase. double-stranded complementary dna (cdna) was synthesized, using the poly-a-tailed rna as a template and oligo-dt as a primer, and then cloned into the puc9 plasmid. virus-specific cdna sequences, varying in length from 0.5 to 2.5 kilobases (kb), were o ... | 1989 | 2562207 |
| [molecular characterization of the hog cholera virus]. | the molecular biology of hog cholera virus (hcv) was studied. after reverse transcription of the viral rna the cdna was cloned in the expression vector lambda gt11. hcv clones were identified using antibodies as a probe. partial sequencing of one hcv-derived cdna clone revealed a high degree of homology to a portion of the bovine viral diarrhea virus (bvdv). one goal of these studies is the preparation of defined, effective and safe vaccines against pestiviruses. | 1989 | 2590156 |
| [bovine virus diarrhea/mucosal disease virus: diagnosis and approach in clinical practice]. | recent studies on bovine virus diarrhoea (bvd virus) afforded a deeper understanding of the epizootiology of this virus. it is of vital importance to determine whether bvd virus infection occurs within the uterus prior to the 120th day of gestation, during a later stage of pregnancy or after birth. when infection occurs before the 120th day of gestation, normal or abnormal calves which persistently carry the bvd virus, will be delivered. when infection occurs during a later stage of gestation, t ... | 1989 | 2678589 |
| detection and elimination of adventitious agents in continuous cell lines. | the national veterinary services laboratories (nvsl) routinely monitors continuous cell lines (ccl's) used for veterinary biologicals and diagnostic virology. all veterinary biologicals produced in ccl's must follow the master seed concept which limits the use of the master seed ccl to up to 20 passages beyond the passage level characterized and deposited at nvsl. all cll's are evaluated for the presence of adventitious agents such as mycoplasma, bovine viral diarrhea virus, and other bacteria a ... | 1989 | 2759356 |
| molecular cloning and nucleotide sequence of the genome of hog cholera virus. | a cdna clone derived from genomic rna of hog cholera virus (hcv) was identified using an oligonucleotide complementary to the rna encoding a hexapeptide from the putative rna-dependent rna polymerase of the closely related bovine viral diarrhea virus (bvdv). this clone served as a probe for screening different size-selected cdna libraries. after molecular cloning and nucleotide sequencing the hcv genome was shown to consist of 12,284 nucleotides containing one long open reading frame. sequence c ... | 1989 | 2763466 |
| the frequency, distribution and effects of antibodies, to seven putative respiratory pathogens, on respiratory disease and weight gain in feedlot calves in ontario. | during 1983-85, 279 calves requiring treatment for bovine respiratory disease and 290 comparison (control) animals from 15 different groups of feedlot calves were bled on arrival and again at 28 days postarrival. their sera were then analyzed for antibodies to seven putative respiratory pathogens. on arrival, the prevalences of indirect agglutination titers to pasteurella haemolytica, p. haemolytica cytotoxin, mycoplasma bovis and m. dispar were greater than 50%, the prevalence of titers to bovi ... | 1989 | 2766158 |
| interaction between pasteurella haemolytica, sulfadiazine/trimethoprim, and bovine viral diarrhea virus. | a study was designed to develop and define a sc tissue chamber as a suitable device for establishing a soft-tissue infection model in cattle and to use this model to study the interaction between pasteurella haemolytica, sulfadiazine/trimethoprim, and bovine viral diarrhea virus (bvdv). thermoplastic tissue chambers were implanted in the paralumbar fossae of 20 calves. at 35 days after implantation, calves were allotted to 4 groups of equal size and the calves in 2 groups were inoculated intratr ... | 1989 | 2802333 |
| thrombocytopenia associated with acute bovine virus diarrhea infection in cattle. | thrombocytopenia was observed in 15 of 146 cases of clinically acute bovine viral diarrhea virus (bvdv) infection in adult cattle. platelet counts ranged from 2,000 to 33,000/microliters. clinically, a bleeding tendency was manifested by bloody diarrhea, petechial and ecchymotic hemorrhage, epistaxis, and abnormal bleeding from injection sites. coagulation testing (six cases) gave no evidence of disseminated intravascular coagulation. bone marrow aspirates were suggestive of active marrow necros ... | 1989 | 2926719 |
| genetic comparison of ovine and bovine pestiviruses. | viral rna oligonucleotide fingerprinting was used to compare genetic relationship among pestiviruses originating from ovine or bovine host species. ovine pestiviruses, including reference border disease virus and 2 border disease isolates originating from natural pestivirus infections of sheep, appeared to have a more distant genetic relationship among themselves than with certain bovine pestiviruses. a closer genetic relatedness was evident between border disease virus and 3 noncytopathic bovin ... | 1990 | 1964772 |
| some immune responses in cattle exposed to mycobacterium paratuberculosis after injection with modified-live bovine viral diarrhea virus vaccine. | delayed-type hypersensitivity responses to mycobacterium paratuberculosis purified protein derivative (ppd) were decreased in cows experimentally exposed to m. paratuberculosis 7 days after exposure to a modified-live bovine viral diarrhea virus (ml-bvdv) vaccine. in vitro lymphocyte blastogenic responses to phytohemagglutinin were decreased in each of 3 cows 7 days after exposure to ml-bvdv vaccine. also, decreased lymphocyte blastogenic responses to m. paratuberculosis ppd were observed in cul ... | 1990 | 1965582 |
| prospective serology and analysis in diagnosis of dairy cow abortion. | a prospective serologic investigation was undertaken on 3 california dairies (herds 1, 3, and 4, as previously designated in a report on abortion surveillance) to determine if fetal loss was associated with infectious disease agents in cows. the diagnostic problem in these herds was typical of many dairies in that abortions were not discovered for several months and aborted fetuses were seldom recovered. blood from approximately 100 pregnant cows in each herd was sampled at monthly intervals, be ... | 1990 | 1965632 |
| diagnosis of bovine viral diarrhea virus infection using monoclonal antibodies. | the monoclonal antibody (mab) d89 against bovine viral diarrhea virus (bvdv) was used in conjunction with fluorescein-conjugated anti-mouse immunoglobulin in an indirect fluorescent antibody (ifa) procedure on frozen tissue sections and cell culture. during the 2-year study, bvdv was isolated from specimens submitted in 460 cases. the d89 mab detected all but 2 bvdv isolates, both cytopathic. in 316 of the cases in which bvd virus was detected by ifa, specimens were inoculated on bovine turbinat ... | 1990 | 1965635 |
| molecular biology of bovine virus diarrhoea virus. | our understanding of the molecular biology of bovine virus diarrhoea virus (bvdv) has greatly increased over the past several years. the development of monoclonal antibodies (mab's) has identified a key antigen of bvdv while at the same time providing evidence for considerable variation in this protein. mab's, particularly those directed against the p80 protein, can be developed for use in diagnostic tests while others may be useful in molecular epidemiological studies of bvdv. the successful cl ... | 1990 | 1966716 |
| ruminant pestivirus infection in pigs. | ruminant pestivirus infections of pigs have a worldwide distribution. the prevalence is varied and depends mainly on (i) contact with cattle, (ii) age of pigs and (iii) degree of homology of virus strains used for serology, with field strains of bovine virus diarrhoea virus (bvdv) infecting pigs. emphasis should be laid on sources of bvdv other than cattle, e.g. contaminated vaccines and fetal calf serum. the need for differentiation of pestiviruses (hog cholera, bovine virus diarrhoea and borde ... | 1990 | 1966720 |
| bovine virus diarrhoea virus: speculation and observations on current concepts. | this final chapter highlights the advances and some of the unanswered questions concerning bovine virus diarrhoea virus (bvdv) presented in this review by specialists from around the world. persistently viraemic cattle play an essential role in the dissemination of bvdv but it is suggested that acute infections with the virus are also important. the role of latency is considered but, as yet, there is no evidence that it plays a part in pathogenesis. it is well established that bvdv, border disea ... | 1990 | 1966724 |
| electron microscopy of bovine virus diarrhoea virus. | bovine virus diarrhoea virus (bvdv) has been (tentatively) identified by electron microscopy in purified virus preparations, in infected cell cultures and in tissues and cells from infected animals. these studies have revealed a spherical membrane-bound particle with a diameter of 40-60 nm. the membrane is smooth, bilaminar and surrounds a dense or semi-dense core of 20-25 nm. the core particle may be isometric or hexagonal. in studies of the morphogenesis of bvdv in infected cell cultures, it w ... | 1990 | 1966727 |
| immunological responses to bovine virus diarrhoea virus infections. | infection of normal calves with bovine virus diarrhoea virus (bvdv) is a transient self-limiting infection that can result in a period of immunosuppression. the virus appears to be able to replicate in all of the major lymphocyte sub-populations as well as in accessory cells. this may result in the leukopenia that is often a sequel of infection and affects b-cells as well as the t-cell sub-populations expressing either bocd4 or bocd8 antigens. b and t-cell responses are affected as a consequence ... | 1990 | 1966728 |
| cytopathic and non-cytopathic biotypes of border disease virus induce polypeptides of different molecular weight with common antigenic determinants. | ten monoclonal antibodies have been raised against lysates of cells infected with cytopathic border disease virus (bdv). these antibodies all recognize non-cytopathic bdv and react with a number of different strains of bovine viral diarrhoea virus (bvdv). studies with radiolabelled cell lysates show that all the antibodies precipitate two polypeptides of apparent mr 80,000 and 130,000 from cells infected with cytopathic virus and a single polypeptide of apparent mr 120,000 from cells infected wi ... | 1990 | 1693167 |
| identification of conserved epitopes on a hog cholera virus protein. | eight monoclonal antibodies directed against the hog cholera virus (hcv) strain alfort/187 and displaying broad cross-reactivity with other hcv strains were characterized. an enzyme immunoassay on fixed monolayers of porcine or bovine cells infected with 14 different strains and isolates of hcv and 12 bovine viral diarrhea viruses (bvdv), respectively, showed that all antibodies reacted with hcv only. seven antibodies recognized all hcv tested, thus indicating that they were directed against con ... | 1990 | 1693844 |
| monoclonal antibodies to the p80/125 gp53 proteins of bovine viral diarrhea virus: their potential use as diagnostic reagents. | monoclonal antibodies reactive to the bovine viral diarrhea virus (bvdv) protein gp53 were produced and characterized. these antibodies and our panel of anti-p80/125 monoclonal antibodies were tested for their cross-reactivity with 11 different north american and european (danish) bvdv strains and isolates including viruses of both cytopathic and noncytopathic biotypes. the four anti-gp53 monoclonal antibodies were neutralizing for the homologous danish cytopathic isolate and cross-reacted with ... | 1990 | 1696159 |
| comparison of persistence of seven bovine viruses on bovine embryos following in vitro exposure. | the ability of seven cytopathic strains of bovine viruses to adhere to the zona pellucida of six-to-eight day-old bovine embryos were compared. embryos were exposed to virus by placing them either in virus suspensions or by culturing them on infected bovine turbinate cultures for 18-24 h. after exposure to bovine virus diarrhea virus (bvdv), infectious bovine rhinotracheitis virus (ibv), bluetongue virus (btv), pseudorabies virus (prv), vesicular stomatitis virus (vsv), parainfluenza 3 virus (pi ... | 1990 | 2107070 |
| clinical aspects of bovine virus diarrhoea virus infection. | bovine virus diarrhoea virus (bvdv) infection of cattle results in a wide range of clinical manifestations. this article reviews the clinical responses associated with bvdv and discusses these diseases in terms of acute infection in immunocompetent cattle, fetal infection, infection in cattle immunotolerant to and persistently infected with bvdv and finally mucosal disease. | 1990 | 2132152 |
| the pathogenesis of bovine virus diarrhoea virus infections. | bovine virus diarrhoea virus (bvdv) disease in cattle ranges from the transient acute infections, which may be inapparent or mild, to mucosal disease which is inevitably fatal. on occasions the acute infections can lead to clinical episodes of diarrhoea and agalactia but as these syndromes cannot be reproduced experimentally, the pathogenesis remains unclear. the immunosuppressive effect of acute bvdv infections can enhance the clinical disease of other pathogens and this may be an important par ... | 1990 | 2132154 |
| epidemiology of bovine virus diarrhoea virus. | a better understanding of the epidemiology and pathogenesis of bovine virus diarrhoea virus (bvdv) has emerged in recent years. fetal infections and in particular those resulting in birth of persistently infected calves are of central importance for the epidemiology of bvdv. a prevalence of persistently infected, viraemic animals of about 1% is found in denmark and elsewhere by examination of randomly collected blood samples. a recent field study shows that 53% of randomly selected herds in an a ... | 1990 | 2132155 |
| thrombocytopenia and hemorrhages in veal calves infected with bovine viral diarrhea virus. | the relationship between bovine viral diarrhea virus (bvdv) infection and thrombocytopenia was studied in 18 veal calves experimentally infected with bvdv. all calves were free of bvdv, and 13 calves were free of serum neutralizing antibodies to bvdv before virus inoculation. calves were inoculated at approximately 10 days of age, and platelet counts were monitored over a period of several weeks. ten additional calves housed in close proximity were kept as uninoculated controls. a profound decre ... | 1990 | 2154423 |
| attempts to characterize bovine viral diarrhea virus isolated from cattle after immunization with a contaminated vaccine. | bovine viral diarrhea virus (bvdv) was isolated from 28 animals with a history of immunization against respiratory disease with a vaccine contaminated with bvdv. the vaccine-derived parental virus strain and the 28 isolates were analyzed using 10 monoclonal antibodies (mabs) directed against different epitopes and antigenic domains on the major envelope glycoprotein of bvdv. none of the isolates displayed a reaction pattern identical with the parental virus. instead, seven different reaction pat ... | 1990 | 2155768 |
| experimental transmission of bovine viral diseases by insemination with contaminated semen or during embryo transfer. | three experimental approaches were used to study transmission of blue tongue (bt), infectious bovine rhinotracheitis (ibr) and bovine virus diarrhoea (bvd) viruses. these were insemination with contaminated semen, experimental infection of embryo donor cows, or transfer of embryos experimentally exposed to virus in vitro to normal recipients. parameters assessed included number and quality of embryos produced, virus detection (isolation and electron microscopy), serology and histopathology. all ... | 1990 | 2155769 |
| hepatitis c virus shares amino acid sequence similarity with pestiviruses and flaviviruses as well as members of two plant virus supergroups. | hepatitis c virus (hcv) is an important human pathogen that is associated with transfusion-related non-a, non-b hepatitis. recently, hcv cdna was cloned and the nucleotide sequence of approximately three-quarters of the virus genome was determined. a region of the predicted polyprotein sequence was found to share similarity with a nonstructural protein encoded by dengue virus, a member of the flavivirus family. we report here that hcv shares an even greater degree of protein sequence similarity ... | 1990 | 2156259 |
| effect of host cell on the in vitro characteristics expressed by two bovine viral diarrhea virus strains. | growth curves, immunofluorescence assays and radioimmunoprecipitation analysis of bovine viral diarrhea virus (bvdv)-specified polypeptides were used to determine the susceptibility of bovine endothelial cells (becs) to infection with strains of bvdv. one strain of the virus, ny1, normally non-cytopathic when grown in bovine turbinate cells (btus), did not parallel this type behavior in becs. virus replication kinetics, morphological changes in infected cells and resolution of viral polypeptides ... | 1990 | 2156373 |
| a study of some pathogenetic aspects of bovine viral diarrhea virus infection. | the cytopathic (cp) tvm-2 strain of bovine viral diarrhea virus (bvdv) induced in calves a severe disease, characterized by the clinical picture which is usually reported for the acute primary infection observed under natural conditions. in contrast, the calves inoculated with a different biotype of bvdv, the non-cytopathic (ncp) new york-1 strain, remained clinically normal with the only evidence of virus replication in these calves being the recovery of the virus from their pharyngeal swabbing ... | 1990 | 2157576 |
| antibodies to bovine parvovirus acquired by neonatal pigs through ingestion of virus and antibody in the diet. | the ability of pigs to respond immunologically to ingestion of bovine parvovirus (bpv) was tested by feeding 4 cesarean-derived, colostrum-deprived (cdcd) pigs a live virus-contaminated, liquid diet for the first 4 weeks of life. virus-neutralizing (vn) antibodies were detected in the serum of 2 of the 4 pigs when they were 4 weeks old. antibody titer remained at about the same level for several weeks, then decreased during the remainder of the 29-week interval of testing. the relative reactivit ... | 1990 | 2158254 |
| insemination of susceptible and preimmunized cattle with bovine viral diarrhoea virus infected semen. | six susceptible and six preimmunized heifers were inseminated with semen from a bull persistently infected with bovine viral diarrhoea virus (bvdv). they had poor rates of conception, but ultimately, all but one conceived. eleven, apparently normal, calves were born, none of which showed evidence of bvdv infection. | 1990 | 2158848 |
| an enzyme-linked immunosorbent assay (elisa) for antibodies to bovine viral diarrhea virus. | a single dilution enzyme-linked immunosorbent assay (elisa) was developed to detect antibodies to bovine viral diarrhea (bvd) virus in cattle sera. viral antigen (nadl strain) was grown in a pig kidney cell line (pk15), and after removal of nuclear debris, was purified by ultracentrifugation through a potassium tartrate cushion. antigen grown in embryonic bovine tracheal epithelial cells was also satisfactory. the test used a high salt buffer to minimize nonspecific reactivity, polyethylene glyc ... | 1990 | 2159672 |
| range of viral neutralizing activity and molecular specificity of antibodies induced in cattle by inactivated bovine viral diarrhea virus vaccines. | the range of neutralizing activity to bovine viral diarrhea (bvd) virus and viral protein specificity of antibodies induced by 3 inactivated vaccines were evaluated by use of samples of sera obtained from 13 cattle 14 days after vaccination. viral neutralizing antibodies wee detected in all cattle to each of 10 noncytopathic and 10 cytopathic isolates of bvd virus. a viral-induced polypeptide (53,000 to 56,000 daltons) was detected by radioimmunoprecipitation with serum from all vaccinates. othe ... | 1990 | 2159737 |
| in vitro interactions of cytokines and bovine viral diarrhea virus in phytohemagglutinin-stimulated bovine mononuclear cells. | bovine viral diarrhea (bvd) virus inhibited phytohemagglutinin (pha)-stimulated bovine peripheral blood mononuclear cell (pbmc) proliferation and bovine interleukin-2 (il-2) production. in the controls, the heat-inactivated bvd virus was not capable of suppressing the pha-stimulated pbmc proliferation. presence of exogenous cytokines, such as purified human il-2, recombinant bovine interleukin-1 (rbovil-1), recombinant bovine il-2, and recombinant human il-6 failed to reverse the bvd virus-induc ... | 1990 | 2161582 |
| intracellular virus-induced polypeptides of pestivirus border disease virus. | intracellular virus specific polypeptides of pestivirus, border disease virus (bdv) in bovine turbinate cells were analysed by radio-immunoprecipitation with specific antisera. eleven viral polypeptides with molecular weights of 220, 165, 118, 84, 66, 58, 55, 53, 45, 37 and 31 kda, respectively, were detected in infected cells. of these, the 165, 118, 84, 66, 58, 55, 53, 45 and 31 kda proteins were found to be glycosylated. comparative studies indicated that the polypeptides induced by bdv share ... | 1990 | 2161595 |
| in vitro production of antibodies to bovine virus diarrhoea virus by peripheral blood mononuclear cells from cattle immunized by infection. | a method for in vitro production of antibodies to bovine virus diarrhoea virus (bvdv) by peripheral blood mononuclear cells (pbmc) was developed. the pbmc were cultured in microtitre plates coated with detergent-solubilized bvdv and the supernatants were tested in an enzyme-linked immunosorbent assay which detects igg antibodies to bvdv. following incubation of pbmc with an optimal concentration of pokeweed mitogen for 5 days, antibodies to bvdv were detected in culture supernatants of pbmc from ... | 1990 | 2162096 |
| molecular cloning and nucleotide sequence of hog cholera virus strain brescia and mapping of the genomic region encoding envelope protein e1. | genomic rna of hog cholera virus (hcv) strain brescia was cloned and sequenced. the nucleotide sequence was deduced from overlapping cdna clones and comprises 12,283 nucleotides. we cloned the complete 3' end of the hcv genome, but could not unequivocally prove that the cdna sequence also completely covers hcv rna at the 5' end. the hcv genome contained one large open reading frame, which spans the viral plus strand rna and encodes an amino acid sequence of 3898 residues with a calculated molecu ... | 1990 | 2162104 |
| specific sequence amplification of bovine viral diarrhoea virus nucleic acid. | bovine viral diarrhoea virus (bvdv) causes infection of cattle worldwide and is a common contaminant of cell cultures in the laboratory. methods of diagnosis for bvdv are time-consuming and inconsistent. we describe the development of an in vitro test based on enzymatic dna amplification with thermus aquaticus dna polymerase of sequences of bvdv cdna reverse transcribed from viral rna. specific sequences were amplified from infected cell cultures and clinical material using laboratory and field ... | 1990 | 2162162 |
| viral protein production in homogeneous and mixed infections of cytopathic and noncytopathic bvd virus. | experiments were conducted to examine dual infection of cultured cells with cytopathic and noncytopathic bovine viral diarrhea virus (bvdv). cell monolayers infected with a noncytopathic bvdv isolate and subsequently superinfected with a cytopathic bvdv isolate were refractive to the cytopathic effects of the cytopathic bvdv isolate, as reported in the literature. immunofluorescence staining of superinfected cultures with monoclonal antibodies specific for the cytopathic or the noncytopathic vir ... | 1990 | 2162163 |
| detection of bovine viral diarrhea virus genome in leukocytes from persistently infected cattle by rna-cdna hybridization. | a bovine viral diarrhea virus (bvdv) cdna library was constructed. one cloned complementary dna sequence was used as a probe to detect bvdv rna by hybridization in infected cell cultures and in mononuclear leukocytes from persistently infected cattle by dot blot and in situ hybridization. the cdna probe hybridized with all cytopathic and noncytopathic bvdv isolates tested. the hybridization results were consistent with results obtained using conventional subculturing and immunofluorescent staini ... | 1990 | 2162729 |
| surveillance for persistent bovine viral diarrhea virus infection in four artificial insemination centers. | four large bovine artificial insemination centers implemented a program of surveillance of resident and newly acquired bulls for persistent bovine viral diarrhea virus infection. infection was identified in 12 of 1,538 bulls. several clinical abnormalities, including acute and chronic mucosal disease, were evident among the persistently infected bulls. semen produced by such bulls consistently contained bovine viral diarrhea virus, and such contamination was not always accompanied by diminished ... | 1990 | 2163996 |
| the coding region for the 54-kda protein of several pestiviruses lacks host insertions but reveals a "zinc finger-like" domain. | we sequenced cdnas, amplified by the polymerase chain reaction (pcr), which correspond to the carboxy-terminal portion of the 54-kda protein of various cytopathic (cp) or noncytopathic (ncp) pestiviral strains. except for the previously described insertions in two cp strains of the bovine viral diarrhea virus (bvdv), we did not find comparable insertions in this gene in eight pestiviral strains. the predicted amino acid sequences of this 54-kda protein portion contain a conserved cysteine-rich s ... | 1990 | 2164736 |
| a group level analysis of the associations between antibodies to seven putative pathogens and respiratory disease and weight gain in ontario feedlot calves. | the associations, at the group level, between serological titer to pasteurella haemolytica surface antigens (ph), pasteurella haemolytica cytotoxin (ph-cytox), infectious bovine rhinotracheitis virus (ibrv), bovine virus diarrhea virus (bvdv), parainfluenza-3 virus (piv3), respiratory syncytial virus (rsv), mycoplasma dispar (md), m. bovis (mb), and respiratory disease treatment rates, relapse rates, and 28 day weight gains were investigated in 14 groups of calves entering two feedlots during ye ... | 1990 | 2165846 |
| antigenic variations in bovine viral diarrhea viruses detected by monoclonal antibodies. | five murine monoclonal antibodies (mabs) against the nadl strain of bovine viral diarrhea (bvd) virus were developed, identified, and characterized. four of the mabs were directed against a 53-kilodalton (kda) viral protein, and one was specific to a 47-kda polypeptide. competitive radioimmunoassay showed that two mabs were specific to related epitopes of the 53-kda protein, and the other three mabs were each specific to a different epitope. the mabs were used to study heterogeneity among bvd vi ... | 1990 | 2168436 |
| characterization of a panel of monoclonal antibodies and their use in the study of the antigenic diversity of bovine viral diarrhea virus. | a panel of 40 monoclonal antibodies (mab) specific for bovine viral diarrhea virus (bvdv) was produced, and each mab was characterized and grouped according to its viral protein specificity, immunoglobulin subclass, virus-neutralizing activity, and immunoreactivity with a large collection of bvdv isolates. the mab were found to be specific for 1 of 3 sets of related viral-induced proteins found in cells infected with the singer strain of bvdv. group-1 mab were specific for the 80- and 118-kiloda ... | 1990 | 2168687 |
| experimental primary postnatal bovine viral diarrhea viral infections in six-month-old calves. | eight clinically healthy calves were inoculated intranasally, four with either noncytopathic or four with cytopathic bovine viral diarrhea virus, and were necropsied 5 or 12 days post-inoculation. the most frequent gross lesion associated with noncytopathic or cytopathic viral infection was proximal colonic mural edema. consistent microscopic findings were acute to subacute tracheitis, mild enterocolitis with edema, petechial hemorrhages of mesenteric lymph nodes with mild follicular lymphocytic ... | 1990 | 2169664 |
| elisa detection of bovine viral diarrhoea virus specific antibodies using recombinant antigen and monoclonal antibodies. | a panel of monoclonal antibodies was prepared by immunization of balb/c mice with moredun (bd) virus strains. these antibodies were characterized by immunofluorescence and seroneutralization against bd, bvd and hog cholera (hc) virus strains, and radioimmunoprecipitation of bvd-infected cells extracts. the mabs reacting with the majority of the pestivirus strains recognize the 80 kda antigen of the bvd cytophathic strains. the 80 kda antigen of the bvd/osloss virus strain has been cloned and exp ... | 1990 | 2169672 |
| immunohistological detection of bovine viral diarrhoea virus antigen in the central nervous system of persistently infected cattle using monoclonal antibodies. | in a total of 25 cattle persistently infected with bovine viral diarrhoea virus (bvdv) the distribution of viral antigens in the central nervous system was studied. using a panel of monoclonal antibodies (anti pestivirus c16; anti cytophathic bvdv c38; anti cytopathic and non-cytopathic bvdv c42; anti gp53 bvdv ca-1 and ca-3) and the indirect immunoperoxidase technique, bvdv antigen was located exclusively in neurons. predilection sites for viral persistence were cerebral cortex and hippocampus. ... | 1990 | 2169673 |
| pathogenesis of mucosal disease and molecular aspects of bovine virus diarrhoea virus. | studies carried out over three decades, on the pathogenesis and epidemiology of bovine virus diarrhoea virus (bvdv), have provided the basis for our understanding of the aetiology of mucosal disease. experimental reproduction of the disease has demonstrated the mechanism of sequential infection and the role of the two virus biotypes. the need for "homogeneity" between the biotypes, causing mucosal disease, has demonstrated the precision of immunotolerance. the origin of the cytopathogenic biotyp ... | 1990 | 2169681 |
| investigation of bovine viral diarrhea virus infections in a range beef cattle herd. | bovine viral diarrhea virus (bvdv) infections resulting in clinical disease developed in calves, despite vaccination of dams and high maternal bvdv antibody titers in calves. eight persistently infected (pi) calves born to immunocompetent dams were identified in the herd. neutralizing bvdv antibody titers of pi calves had decreased greatly by the time the calves were 1 to 2 months old. antibody titers of pi calves decreased more rapidly than antibody titers of calves that were not pi. reduced an ... | 1990 | 2170313 |
| comparative pathogenicity of selected bovine viral diarrhea virus isolates in gnotobiotic lambs. | the infectivity and pathogenicity of selected bovine viral diarrhea virus (bvdv) isolates were determined in gnotobiotic, colostrum-deprived neonatal lambs. five-day-old cesarean-derived gnotobiotic lambs were exposed to 1 of 10 bvdv isolates via aerosol suspension. these isolates were from tissues or secretions of calves or lambs affected with respiratory tract disease, weak neonatal calves, aborted bovine fetuses, or reference singer or draper bvdv. the pathogenicity of each isolate, relative ... | 1990 | 2173447 |
| frequency of association of noncytopathic bovine viral diarrhea virus with bovine neutrophils and mononuclear leukocytes before and after treatment with trypsin. | enriched populations of neutrophils and mononuclear leukocytes from 9 cattle persistently infected with noncytopathic bovine viral diarrhea virus were analyzed for frequency of association with virus, using flow cytometric procedures. trypsinization of neutrophils decreased the frequency of viral association from 0.82% to 0.49%. similar treatment of mononuclear leukocytes decreased the frequency of viral association from 5.53% to 4.81%. results of immunocytochemical procedures to locate viral an ... | 1990 | 2173452 |
| flow cytometric detection of bovine viral diarrhea virus in peripheral blood leukocytes of persistently infected cattle. | flow cytometry was investigated for detection of bovine viral diarrhea virus (bvdv) in peripheral blood mononuclear leukocytes of persistently infected cattle. the mononuclear leukocytes were purified by sedimentation in a gradient of ficoll-paque, fixed, permeabilized, and then labelled by indirect immunofluorescence using biotinylated immunoglobulins from a porcine antiserum to bvdv. flow cytometric analysis of blood samples obtained from persistently infected cattle revealed virus in 3.0-21.0 ... | 1990 | 2174298 |
| experimental pestivirus infections in newborn goat kids. | two experiments were carried out in which 37 healthy newborn goat kids were inoculated with a non-cytopathic ovine (bdv) or a cytopathic bovine pestivirus (bvdv) by intramuscular or intracerebral injection. no kids showed signs of disease or gross lesions which could be attributed to these viruses, but inoculated kids had lower mean growth rates than the controls. significant histological changes in the cns of 14 kids were restricted largely to the white matter and consisted mainly of hypercellu ... | 1990 | 2175318 |
| detection of bovine viral diarrhea virus in serum from cattle by dot blot hybridization assay. | a dot blot hybridization assay was developed for use as a rapid screening test to detect bovine viral diarrhea virus (bvdv) in serum from infected cattle. a 1.1. kilobase cdna, prepared from the bvdv genome, was molecularly cloned and used in this study. insert cdna was removed from the puc9 plasmid vector by pst-i restriction endonuclease digestion and purified from plasmid dna by agarose electrophoresis and electroelution. the hybridization probe was prepared by nick translation in the presenc ... | 1990 | 2175527 |
| antigenic comparisons of hog cholera virus isolates from europe, america and asia using monoclonal antibodies. | nineteen monoclonal antibodies (mabs) with specificity for hog cholera virus (hcv) were prepared. they were used in an immune binding (peroxidase linked) assay to determine the reaction patterns of hcv isolates from europe, brazil, usa, japan and malaysia, as well as laboratory reference strains of the virus. a further panel of 17 mabs raised against bovine virus diarrhoea virus (bvdv) was included in the study, together with 5 mabs raised against a non-hcv pestivirus of porcine origin. all the ... | 1990 | 2178905 |
| a new approach for the diagnosis of hog cholera. | pestiviruses were isolated from seven cases of suspect hog cholera. using peroxidase conjugates of monoclonal antibodies (mabs) six isolates were identified as hog cholera viruses (hcv), while one isolate was of ruminant origin, possibly bovine viral diarrhea virus. in parallel attempts were made to develop an elisa for the detection of hcv-specific antibodies in pig sera. the mab hctc26 coated to polystyrol plates efficiently captured the major viral glycoprotein gp53 from crude antigen suspens ... | 1990 | 2178908 |
| attaching and effacing escherichia coli infection as a cause of diarrhea in young calves. | a form of enteric escherichia coli infection was identified in 60 calves from 59 farming operations. the e coli responsible for these infections principally colonized the colon, inducing a distinctive lesion described as attaching and effacing. hemorrhagic enterocolitis or blood in the feces was observed on 40% of the farms. of affected calves, 86.6% were dairy calves (average age, 11.8 days). forty-four calves were infected concurrently with other enteropathogens (cryptosporidia, rotavirus, cor ... | 1990 | 2179181 |
| [epidemiologic studies of the detection of viral infection agents in calf losses in the weser-ems region]. | in 961 calves up to an age of 6 months which were sent to the animal health center in oldenburg between march 1987 and march 1990 for necropsy the results of determination of different viruses were calculated: bvd-, rota-, corona-, parainfluenza-3- (pi-3)-, bovine herpes-1 (bhv-1)- and bovine respiratory syncytial virus (brsv). in 122 and 104 randomly collected health calves of 22 farms antibodies against brsv and bovine adeno virus-types 5, 7 and 8 were determined. 50.1% of the necropsied calve ... | 1990 | 2245783 |
| bovine viral diarrhea virus-induced cerebellar disease in a calf. | bovine viral diarrhea virus (bvdv) was isolated from buffy coat cells of a 10-day-old calf with signs of cerebellar disease--ataxia, hypermetria, and intention head tremor. the tentative diagnosis was bvdv-induced cerebellar hypoplasia. at necropsy, gross lesions were not identified. histologic findings suggested bvdv-induced diffuse hypomyelination throughout the cns, as reported in the united kingdom and the netherlands. | 1990 | 2276963 |
| pestivirus glycoprotein which induces neutralizing antibodies forms part of a disulfide-linked heterodimer. | neutralizing monoclonal antibodies directed against hog cholera virus (hcv) precipitated two hcv-encoded glycoproteins, hcv gp55 and hcv gp33. immunoassay with bacterial fusion proteins and western immunoblotting with extracts from infected cells revealed that the antibodies recognized only hcv gp55. coprecipitation of hcv gp33 was shown to be due to intermolecular disulfide bridges. one of the antibodies also reacted with the major glycoprotein of another pestivirus, bovine viral diarrhea virus ... | 1990 | 2370675 |
| prevalence of antibodies to infectious bovine rhinotracheitis, parainfluenza 3, bovine respiratory syncytial, and bovine viral diarrhea viruses in cattle in saskatchewan and alberta. | a total of 1745 healthy cattle from 295 farms in saskatchewan and alberta was tested by elisa for antibodies to four viruses. antibodies to infectious bovine rhinotracheitis (ibr) virus were found in 37.8% of sera (59.5% of properties), to parainfluenza 3 (pi3) virus in 93.9% of sera (99.7% of properties), to bovine respiratory syncytial (brs) virus in 78.5% of sera (86.6% of properties), and to bovine viral diarrhea (bvd) virus in 40.6% of sera (66.7% of properties)the prevalence of pi3 viral a ... | 1990 | 17423704 |
| comparative serological response in calves to eight commercial vaccines against infectious bovine rhinotracheitis, parainfluenza-3, bovine respiratory syncytial, and bovine viral diarrhea viruses. | a field trial was conducted to compare the serological responses in calves to eight commercial vaccines against infectious bovine rhinotracheitis virus (ibrv), parainfluenza-3 virus (pi3v), bovine respiratory syncytial virus (brsv), and/or bovine viral diarrhea virus (bvdv). calves given ibrv, p13v, brsv, and bvdv vaccines had significantly higher antibodies to these viruses than unvaccinated controls; however, serological responses to killed bvdv vaccines were low. calves with preexisting antib ... | 1991 | 17423913 |
| an outbreak of fetal and neonatal losses associated with the diagnosis of bovine viral diarrhea virus. | a severe outbreak of dairy herd pregnancy wastage was investigated. at the beginning of the outbreak, a total of 121 lactating cattle were pregnant and considered to be at risk. overall, 33.1% of the population at risk aborted, while 25.6% gave birth to calves that either died during the early neonatal period or demonstrated signs compatible with congenital defects (abnormal births). a laboratory diagnosis of bovine viral diarrhea virus (bvdv) infection was made in two surviving neonatal calves ... | 1991 | 16727029 |
| rapid detection of bovine viral diarrhea virus by polymerase chain reaction. | the polymerase chain reaction was used to detect genomic sequences of the positive-stranded rna of bovine viral diarrhea virus (bvdv), a member of the family togaviridae. using a set of 20-bp primers located within the conserved 3' region of the bvdv genome, we were able to consistently amplify a 205-bp target sequence from bvdv cdna. bvdv rnas from cell culture-propagated bvdv reference strains, diverse unrelated cytopathic and noncytopathic field isolates, and clinical serum samples were trans ... | 1991 | 1709950 |
| immunofluorescence studies of biotype-specific expression of bovine viral diarrhoea virus epitopes in infected cells. | the expression of biotype-specific epitopes in cells infected with cytopathic (cp) and non-cytopathic (ncp) bovine viral diarrhoea virus (bvdv) was analysed by immunofluorescence. four monoclonal antibodies (mabs) directed against different epitopes on the viral glycoprotein gp48 were used. with cells infected with cpbvdv strain nadl, the four mabs yielded a strong and granular cytoplasmic fluorescence. the same pattern was observed when cells were infected with ncpbvdv 7443 with two of the mabs ... | 1991 | 1714946 |
| primary bovine viral diarrhoea virus infection in calves following direct contact with a persistently viraemic calf. | six calves, aged 24 to 58 days and not previously exposed to bovine viral diarrhoea virus (bvdv), were infected with this agent by nose-to-nose contact with a persistently bvdv viraemic calf. the study was conducted in two trials, using 3 calves in each. all 6 calves showed a peak interferon level in serum at 4 days post infection (dpi), and they seroconverted to bvdv at 16-21 dpi. the calves in trial 1 had diarrhoea for 2 or 3 days between 2 and 6 dpi and one calf again from 9 to 11 dpi. during ... | 1991 | 1719713 |
| anti-idiotypic antibodies mimic bovine viral diarrhea virus antigen. | polyclonal rabbit anti-idiotypic antibodies (anti-ids) against two neutralizing murine monoclonal antibodies (mabs) specific to a bovine viral diarrhea virus (bvdv) glycoprotein, 53 kda, were produced, purified, and characterized. each anti-id inhibited the binding of its respective mab to bvdv antigen in a competitive elisa and blocked the immunoprecipitation of the 53 kda protein by the mab. the anti-ids also inhibited the virus-neutralizing activity of their homologous mabs. these results sug ... | 1991 | 1722928 |
| mass screening of cattle sera against 14 infectious disease agents, using an elisa system for monitoring health in livestock. | mass screening elisa methods were developed for testing cattle serum for antibodies against 14 common livestock diseases simultaneously. the absorbance values were transformed to a %elisa (spectrophotometric antibody end point) by a computer interfaced with a microplate reader. a histogram indicating a cutoff point and a report for the veterinarian also was generated. the computer program produced a print-out of the antibody profile for each animal tested, the antibody concentration against each ... | 1991 | 1767993 |
| production and characterization of monoclonal antibodies against excretory-secretory products of fasciola hepatica. | four monoclonal antibodies (mabs) (9.49, 24.27, 46.71 and 179.57) were produced against fasciola hepatica excretory-secretory products. isotype analysis revealed the antibodies to be igm, igg3, igg1, and igm. in immunoblot assays, the mabs recognized different antigenic polypeptides migrating between 29 and 180 kda. specificity of the mabs was evaluated by elisa against antigens of fascioloides magna, anoplocephala magna, stichorchis subtriquetrus, haemonchus contortus, sheep liver extract (sle) ... | 1991 | 1788930 |
| viral cytopathogenicity correlated with integration of ubiquitin-coding sequences. | the rna genomes of cytopathogenic bovine viral diarrhea virus (bvdv) isolates contain insertions highly homologous to cellular sequences. for two of them the insert was identified as ubiquitin coding sequence. the genome of bvdv osloss contains exactly one ubiquitin gene monomer. in the case of bvdv cp1 the cellular insertion comprises one complete ubiquitin gene and part of a second monomer. the host cell-derived element in the cp1 genome is embedded in a large duplication of about 2.4 kb of vi ... | 1991 | 1846490 |
| transmission of bovine virus diarrhoea virus by blood feeding flies. | three species of blood-feeding flies (stomoxys calcitrans, haematopota pluvialis and hydrotaea irritans) were fed for five minutes on a bullock persistently infected with bovine virus diarrhoea virus (bvdv) containing 10(4.5)tcid50 non-cytopathic bvdv/ml serum, then subsequently fed on bvdv-free seronegative animals maintained in isolation. virus was isolated from recipient animals between days 5 and 10 using h pluvialis, and up to 72 hours after transmission with s calcitrans; virus isolation w ... | 1991 | 1850184 |
| detection of bvd viruses using synthetic oligonucleotides. | this study examined synthetic oligonucleotide probes as potential diagnostic tools for bovine viral diarrhea virus (bvdv). six 20-base sequences from across the genome were selected by homology analysis of the published genomic sequences of the nadl and osloss isolates of bvdv. rna was extracted from 22 bvdv isolates propagated in bovine turbinate (bt) cells, blotted, and probed with 32p end-labeled oligonucleotides. the stringency conditions used were such that more than a single base mismatch ... | 1991 | 1850232 |
| detection of bovine viral diarrhea (bvd) virus using the polymerase chain reaction. | the approach of reverse transcription (rt) followed by the polymerase chain reaction (pcr) was used to amplify three different fragments of the bovine viral diarrhea virus (bvdv) genome. two sets of primers framed two different regions within the gene coding for protein p80, the third set of primers was selected to amplify cdna within the envelope glycoprotein (gp53) region. all three sequences could be detected in the homologous strain (nadl), whereas only some of the fragments could be amplifi ... | 1991 | 1850892 |
| border disease in sheep caused by transmission of virus from cattle persistently infected with bovine virus diarrhoea virus. | two outbreaks of border disease occurred on farms with sheep flocks and breeding cattle. the infection of the pregnant sheep was probably caused by transmission of virus from calves persistently infected with non-cytopathic bovine virus diarrhoea virus (bvdv) which were kept in close confinement with the ewes during mid-pregnancy. border disease was also induced experimentally in eight lambs by exposing their dams at 38 to 78 days of gestation to a heifer persistently infected with bvdv. both th ... | 1991 | 1851350 |
| defective function of leukocytes from cattle persistently infected with bovine viral diarrhea virus, and the influence of recombinant cytokines. | cattle persistently infected with bovine viral diarrhea (bvd) virus have decreased neutrophil and lymphocyte functions. we reevaluated these functions and further characterized the inhibition of persistent bvd virus infection in neutrophils, using sensitive kinetic assays. in addition, the influence of in vitro incubation of neutrophils with recombinant bovine interferon gamma (rboifn gamma) and in vitro incubation of lymphocytes with recombinant bovine interleukin-2 was evaluated. significant ( ... | 1991 | 1852143 |
| hog cholera virus: molecular composition of virions from a pestivirus. | virions from hog cholera virus (hcv), a member of the genus pestivirus, were analyzed by using specific antibodies. the nucleocapsid protein was found to be a 14-kda molecule (hcv p14). an equivalent protein could also be demonstrated for virions from another pestivirus, bovine viral diarrhea virus. the hcv envelope is composed of three glycoproteins, hcv gp44/48, gp33, and gp55. all three exist in the form of disulfide-linked dimers in virus-infected cells and in virions; hcv gp44/48 and gp55 e ... | 1991 | 1870198 |
| cryptosporidiosis in neonatal calves: 277 cases (1986-1987). | from january 1986 through december 1987, 277 cases of cryptosporidiosis in calves were diagnosed by the south dakota state university diagnostic laboratory. cryptosporidium sp was the only pathogen identified in 142 (51.3%) of the calves. concurrent infections with rotavirus, coronavirus, escherichia coli, salmonella sp, bovine viral diarrhea virus, or other pathogens were identified in the remaining 135 calves. after elimination of cases involving autolyzed specimens or calves with chronic diar ... | 1991 | 1874678 |
| [veterinary medicine and molecular biology: possibilities and limits of virus detection]. | in the last years molecular biology has gained more and more influence in veterinary medicine, e.g. in animal breeding. in addition, methods of molecular biology may open new areas in the diagnosis of viral diseases, because they are fast and very sensitive. the following article displays an overview of molecular biological techniques that are currently in use for virus detection. in addition, the limits of these methods are discussed. in particular, the polymerase chain reaction (pcr) is descri ... | 1991 | 1902003 |
| effect of infection by bovine viral diarrhea virus (bvdv) in vitro on interleukin-1 activity of bovine monocytes. | the effect of bovine viral diarrhea virus (bvdv) infection in vitro on the interleukin-1 (il-1) activity of bovine monocytes was studied. supernatants from bvdv-infected monocytes suppressed il-1-stimulated proliferation of mouse thymocytes and masked lipopolysaccharide-stimulated il-1 activity of bovine monocytes in the mouse comitogen thymocyte assay. suppression of mouse thymocyte proliferation was restored by the addition of il-1. il-1 inhibitory activity was induced both by the prototype va ... | 1991 | 1949588 |
| comparison of flow cytometry and virus isolation in cell culture for identification of cattle persistently infected with bovine viral diarrhea virus. | detection of bovine viral diarrhea virus in 143 blood samples by virus isolation in cell culture and flow cytometry was performed. the material included 37 samples later shown to originate from persistently infected cattle. thirty-three samples were positive by virus isolation, and all 37 samples were positive by the flow cytometric assay. | 1991 | 1645374 |
| detection of cattle infected with bovine viral diarrhea virus using nucleic acid hybridization. | a ribonucleic acid (rna) hybridization assay to identify cattle infected by bovine viral diarrhea virus (bvdv) is described. the rna probe was derived from the coding region at the 3' end of the genome of the nadl strain of bvdv. total rna from infected cell cultures or peripheral blood leukocytes from suspect animals was extracted and applied to nylon membranes with a slot blot apparatus. peripheral blood leukocytes were tested concurrently for bvdv by virus isolation. the results of hybridizat ... | 1991 | 1645592 |
| comparison of cytopathic and noncytopathic isolates of bovine viral diarrhea virus by oligonucleotide fingerprinting. | the molecular technique of rna fingerprinting was used to characterize the genomes of 5 isolates of bovine viral diarrhea virus (bvdv): 2 viral pairs from the same animal, bvd-iln/bvd-ilc and bvd-tgan/bvd-tgac, and the cytopathic viral prototype, bvd-nadl. oligonucleotide patterns from the viruses were compared, and unique and overlapping oligonucleotides were identified. a comparison of the fingerprints indicated that the genome of each virus was distinguishable by the t1 rnase oligonucleotide ... | 1991 | 1645593 |
| quantitation of bovine viral diarrhea virus in embryo transfer flush fluids collected from a persistently infected heifer. | 1991 | 1645602 | |
| [a new enzyme immunoassay for the detection of antibodies against the bovine viral diarrhea virus]. | an enzyme-linked immunosorbent assay (elisa), using the nonstructural protein p125/80 of the bovine viral diarrhoea (bvd) virus as antigen, was used for screening bvd-specific antibodies in 468 bovine sera. the results were compared with those obtained in a standard neutralization test (nt). both tests reacted positive with 457 sera. the elisa gave positive results with eight sera which were negative in the nt whereas one serum was positive in the nt and negative in the elisa. two sera could not ... | 1991 | 1646493 |
| the vaccination and challenge with bovine viral diarrhea virus (bvdv) of calves previously infected with a non-cytopathic bvdv. | four calves were infected with noncytopathic (ncp) new york-1 strain of bovine viral diarrhea virus (bvdv). during the observation period of one month the calves remained clinically normal but the virus was repeatedly recovered from their pharyngeal swabbings and blood. thirty days following infection the four calves were vaccinated, together with two uninfected calves, with a modified-live vaccine containing cytopathic (cp) bvdv, infectious bovine rhinotracheitis virus and parainfluenza-3 virus ... | 1991 | 1647929 |
| [use of monoclonal antibodies for the differential diagnosis of pestivirus infections in swine]. | monoclonal antibodies (mab) specific for hog cholera virus (hcv), bovine viral diarrhoea virus (bvdv) or pestivirus were applied for the differential diagnosis of pestivirus infections in pigs. field virus isolated from 8 confirmed classical swine fever outbreaks and one suspect case was propagated in pk(15) cell cultures and identified by direct immunofluorescence (ifa) and peroxidase linked antibody (pla) assays. peroxidase-linked hcv, bvdv and pestivirus specific mab were applied in direct pl ... | 1991 | 1648800 |
| pestivirus gene expression: the first protein product of the bovine viral diarrhea virus large open reading frame, p20, possesses proteolytic activity. | the positive-strand rna genome of pestiviruses contains a single large open reading frame (orf) extending its entire length and is capable of encoding 450 kda of protein. studies have been undertaken with the purpose of elucidating the specific mechanisms involved in the biogenesis of the complete complement of pestivirus proteins. here, we report on gene expression at the 5' end of the genome of the prototype pestivirus, bovine viral diarrhea virus (bvdv). we demonstrate, using both a cell-free ... | 1991 | 1649345 |
| pestivirus bovine viral diarrhea virus polypeptides: identification of new precursor proteins and alternative cleavage pathways. | the genome of pestivirus bovine viral diarrhea virus (bvdv) contains a single 11,964 nt long open reading frame (orf) that is capable of encoding a 449 kda putative polyprotein. although previous studies have described many virus-coded polypeptides that are believed to arise by post- and/or co-translational proteolytic processing in infected cells, there are two separate regions in the orf for which no polypeptide products could be identified. in the present study using site specific antisera, w ... | 1991 | 1651034 |
| pestivirus gene expression: protein p80 of bovine viral diarrhea virus is a proteinase involved in polyprotein processing. | bovine viral diarrhea virus (bvdv), the prototypic pestivirus, possesses a positive-strand rna genome with a single large open reading frame (orf) encoding about 4000 amino acids. we have endeavored to elucidate the mechanisms involved in protein biogenesis by this pestivirus. here, we present our studies on gene expression from the viral nonstructural protein coding region encompassing the carboxy-terminal 60% of the orf. previous sequence and modeling analyses predicted the amino-terminal regi ... | 1991 | 1651596 |
| expression of the p80 region of bovine viral diarrhea virus and identification of specific antibodies to this recombinant protein in bovine sera. | a 917-base pair segment of the bovine viral diarrhea virus (bvdv) genome encoding part of the p80 region was cloned into plasmid gex-2t expression vector for expression as a fusion protein with glutathione-s-transferase (gst). when the p80 and gst sequences were in the same reading frames, the resulting gst-p80 fusion protein had a molecular mass of 58 kilodaltons (kda) in sds-page. extracts of control e. coli carrying only the vector plasmid (gex-2t) did not contain this new 58-kda protein band ... | 1991 | 1651719 |
| prevalence of ruminant pestivirus infections in namibia. | following several clinical cases of suspected bovine virus diarrhoea (bvd) on three namibian cattle farms, a serological survey was conducted on bovine, ovine, caprine and wild ruminant sera originating from different regions of the country. neutralizing antibodies to bvd virus (bvdv) were detected in 58% of 1,014 cattle sera, 14% of 618 sheep sera and 4.6% of 1,118 goat sera. sera from seven of ten wildlife species were positive with kudu, eland and giraffe having prevalence rates greater than ... | 1991 | 1652725 |
| sensitivity and specificity of an enzyme-linked immunosorbent assay for the detection of bovine viral diarrhea virus antibody in cattle. | a reliable bovine viral diarrhea (bvd) viral antigen was prepared from bvd virus grown on madin darby bovine kidney (mdbk) cells by solubilizing the virus with detergent mega-10 (decanoyl-n-methylglucamide) followed by removal of hydrophobic proteins with triton x-100 treatment. by these treatments, problems of high background associated with bvd viral antigen in the enzyme-linked immunosorbent assay (elisa) were eliminated. with this new antigen, an elisa was adapted to detect bovine serum anti ... | 1991 | 1653099 |
| comparative evaluation of the fluorescent antibody test and microtiter immunoperoxidase assay for detection of bovine viral diarrhea virus from bull semen. | an indirect immunoperoxidase staining technique (ip) is described for the detection of bovine viral diarrhea virus (bvdv) in bovine semen. the performance of the ip was compared to the reference immunofluorescent staining test in its ability to detect bvdv in 23 coded field semen samples. the ip assay which can be applied with ease to a large number of samples and does not require expensive fluorescence microscope equipment, appears to be an alternative method for bvdv detection. the ip assay ca ... | 1991 | 1653102 |
| serologic detection and practical consequences of antigenic diversity among bovine viral diarrhea viruses in a vaccinated herd. | samples of sera were obtained from 5,725 cows in a semiclosed herd. in each of the preceding 7 years, the herd was vaccinated against bovine viral diarrhea (bvd) with killed virus. neutralizing antibody tests were done on all samples of sera, using cytopathic virus, bvd-tgac virus, that was antigenically distinct from the vaccine virus. most samples of sera had high titers of neutralizing antibodies against bvd-tgac virus. in 48 samples of sera, neutralizing antibodies were not detected against ... | 1991 | 1654030 |
| replication of bovine viral diarrhoea virus in the bovine reproductive tract and excretion of virus in semen during acute and chronic infections. | five mature bulls were studied during an acute transient infection with bovine viral diarrhoea virus (bvdv). the bulls had been infected experimentally by the intranasal instillation of blood and serum from a cow which was a persistent carrier of the virus. infection was confirmed by the demonstration of a low titred viraemia in four of the five animals and by the seroconversion of all five. semen samples were collected from each bull on four occasions between seven and 14 days after infection. ... | 1991 | 1654660 |
| efficiency of various cloned dna probes for detection of bovine viral diarrhea viruses. | we have evaluated 24 cytopathic (cp) and 37 noncytopathic (ncp) strains of bovine viral diarrhea virus (bvdv) with a dot blot assay using four different genome segments of the nadl strain as hybridization probes (p80, p54, gp53, and gp62). the p80 and p54 probes hybridized to 23/24 (96%) and 22/24 (92%), respectively, of cp strains examined. in contrast, these same two probes only detected 16/37 (43%) and 5/37 (13%), respectively, of the ncp strains examined. the gp53 probe detected 18/24 (75%) ... | 1991 | 1654669 |