Biomedical subjects

S R Bolin

Publications and source records attributed to S R Bolin.

At least 19 recordsLinked to original sources

PubMed1992

Analysis of the bovine viral diarrhea virus genome for possible cellular insertions.

Mucosal disease is the most severe disease resulting from bovine viral diarrhea virus (BVDV) infection in cattle. Two biotypes of BVDV may be isolated from animals with mucosal disease: cytopathic (cp) and noncytopathic (ncp). These "pairs" of cp/ncp viruses are often closely related and it has been suggested that the cp virus arises from a ncp virus by insertion of cellular RNA in the p125 region of the BVDV genome. We have used four pairs of cp/ncp BVDV isolated from cattle with mucosal disease, to examine the genomic sequence of the region of the genome coding for the nonstructural protein p125 (processed to p54/p80 in cp viruses) by PCR analysis and sequencing. We did not detect any cellular gene insertions in any of the four ncp viruses; however, we found a large duplication of the p80 gene and a ubiquitin gene insertion in three of the four cp isolates. Our results suggest that cellular RNA insertions in the p125 region may contribute significantly to the cytopathogenicity of BVDV. However, this does not appear to be the only mechanism of cytopathogenicity as we did not detect any insertions or duplications in one of the cp viruses. Comparison of the DNA sequence in the p80 region revealed greater homology within the "pairs" than to NADL, which lend further support to the hypothesis that a cp virus is originated from a ncp virus.

Amino Acid Sequence↗

PubMed1992

Differences in virulence between two noncytopathic bovine viral diarrhea viruses in calves.

A noncytopathic bovine viral diarrhea virus (BVDV), BVDV-890, isolated from a yearling heifer that died with extensive internal hemorrhages, was compared for virulence in calves with noncytopathic BVDV-TGAN, isolated from an apparently healthy persistently infected calf. After challenge exposure with BVDV-890, nonimmune calves (n = 7) developed fever > 40 C, diarrhea, leukopenia, lymphopenia, neutropenia, and thrombocytopenia. Most calves (n = 6) died or were euthanatized by 19 days after challenge exposure. Challenge exposure with BVDV-890 did not induce disease in 2 calves that had congenital persistent infection with BVDV or in 3 calves that had neutralizing antibody titer > 4 against BVDV-890. After challenge exposure with BVDV-TGAN, nonimmune calves (n = 7) developed fever > 40 C and, rarely, diarrhea or lymphopenia. All of those calves survived challenge exposure. The average maximal titer of BVDV-890 isolated from serum was 1,000 times that of BVDV-TGAN. In calves infected with BVDV-890, the average maximal percentages of lymphocytes and platelets associated with virus were greater than those found in calves infected with BVDV-TGAN. Additional findings of epidemiologic significance were prolonged shedding of virus and delayed production of viral-neutralizing antibody in 1 calf challenge-exposed with BVDV-890. Also, after production of neutralizing antibody, mutant virus that was refractory to neutralization was isolated from calves challenge-exposed with BVDV-TGAN.

Animals↗

PubMed1991

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 would result in no hybridization. The probe originating nearest the 5' end of the viral RNA, ND001, detected 86% of the viral isolates while the other probes detected from 19% to 57%. Both cytopathic and noncytopathic isolates were detected by these synthetic probes. A cocktail of these probes were used to specifically detect BVDV RNA extracted directly from tissues of cattle either persistently or acutely infected.

Animals↗

PubMed1991

Hybridization analysis of genomic variability among isolates of bovine viral diarrhoea virus using cDNA probes.

Genomic variability among 28 cytopathic and 37 non-cytopathic isolates of BVDV was evaluated using hybridization analysis. Total RNA, isolated from cell cultures infected with BVDV, was probed with each of three plasmids containing cDNA derived from the cytopathic BVDV-NADL isolate. The three cDNA plasmid probes represented about 40% of the BVDV-NADL genome. The probes originated from the 5' end of the viral genome, the region of the genome coding for the p80 polypeptide and the 3' end of the genome. Three temperatures, 63 degrees C, 53 degrees C and 43 degrees C, were used for hybridization and washing and allowed approximately 29%, 36%, and 43% mismatch, respectively. Fifteen of the BVD viral isolates differed by less than 29% from BVDV-NADL in all three of the regions probed. Seventeen of the BVD viral isolates differed between 36% and 43% from BVDV-NADL in all three of the regions probed. Ten viral isolates differed by more than 43% from BVDV-NADL in all the regions probed. The remaining viral isolates exhibited different levels of similarity to BVDV-NADL in the three areas probed.

Animals↗

PubMed1991

Antigenic and genomic comparison between non-cytopathic and cytopathic bovine viral diarrhoea viruses isolated from cattle that had spontaneous mucosal disease.

Antigenic and genomic relationships between five pairs of non-cytopathic and cytopathic bovine viral diarrhoea (BVD) viruses isolated from cattle with mucosal disease were examined. Antigenic similarity was evaluated by studying the binding characteristics of 10 monoclonal antibodies (MAbs) directed against the gp53 BVD virus glycoprotein. The MAb binding match between members of the same virus pair ranged from 10/10 to 7/10. The genomic relationships was evaluated by studying the hybridization characteristics of two cDNA probes and six complementary 20 base oligomer probes with virus DNA, selected on the basis of conservation between published BVD virus sequences; cDNA probes were hybridized at two stringencies (60 degrees C and 45 degrees C). The match of hybridization results between members of the same virus pair ranged from 4/4 to 1/4 with the cDNA probes and from 6/6 to 3/6 with the oligomer probes. The results indicate that members of the same virus pair can differ at both the antigenic and genomic levels.

Animals↗

PubMed1991

Methods for detection and frequency of contamination of fetal calf serum with bovine viral diarrhea virus and antibodies against bovine viral diarrhea virus.

Methods used by the National Animal Disease Center to test fetal calf serum for contamination with bovine viral diarrhea virus (BVDV) and antibodies against BVDV are described. Using those methods, virus was isolated from 332 of 1,608 (20.6%) lots of raw fetal calf serum obtained specifically for the Center and 93 of 190 (49%) lots of commercially available fetal calf serum. Virus neutralization and immunoperoxidase staining tests were used to detect antibodies against BVDV in 224 of the 1,608 (13.9%) lots of raw fetal calf serum. Both BVDV and antibodies against BVDV were detected in 50 lots of raw serum. The molecular specificity of antibodies against BVDV was determined by radioimmunoprecipitation. Lots of fetal calf serum that contained BVDV-specific antibodies that did not neutralize virus were identified.

Animals↗

PubMed1991

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 BVD-TGAC virus, but were detected against the vaccine virus. Neutralizing antibodies against selected noncytopathic BVD viruses were not detected in several samples of serum that had neutralizing antibodies against the vaccine virus and BVD-TGAC virus. Noncytopathic BVD virus was isolated from sera obtained from 3 cows less than 4 years old. Two cows were available for further testing, and persistent infection with BVD virus was confirmed in both cows. The BVD viruses isolated from those cows were not neutralized by several samples of sera. Immunoprecipitation of polypeptides induced by the vaccine virus was done with selected samples of serum. Two patterns of immuno-precipitated viral-induced polypeptides were identified. One pattern was consistent with exposure of cows with live virus. The other pattern was consistent with exposure of cows with only the killed virus vaccine.

Animals↗

PubMed1991

Viral contamination of fetal bovine serum used for tissue culture: risks and concerns.

Four viral contaminants have been routinely detected in unprocessed and commercial lots of fetal bovine serum: bacteriophage, infectious bovine rhinotracheitis, parainfluenza-3 and bovine viral diarrhea virus (BVDV). Of those, BVDV is consistently present in a majority of commercial lots of fetal bovine serum. Methods for BVDV detection and removal are reviewed. The tentative role of an unclassified pestivirus in microcephaly of infants has been reported. Its significance remains uncertain.

Animals↗

PubMed1991

Lesions and localization of viral antigen in tissues of cattle with experimentally induced or naturally acquired mucosal disease, or with naturally acquired chronic bovine viral diarrhea.

Tissues from cattle that died of experimentally induced mucosal disease (n = 3), naturally acquired mucosal disease (n = 6), or naturally acquired chronic bovine viral diarrhea (n = 4) were examined. Consistent findings were lymphocytic depletion of lymphoid tissues, degeneration of myenteric ganglion cells, and mild adrenalitis. Intracytoplasmic viral antigen was detected in myenteric ganglia and in endocrine glandular cells. Noncytopathic virus was isolated from all cattle, and cytopathic virus was isolated from 12 of 13 cattle.

Animals↗

PubMed1991

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 (P less than 0.05) decrease in random migration under agarose, Staphylococcus aureus ingestion, cytochrome-C reduction, iodination, antibody-independent cell-mediated cytotoxicity, oxidant production, and cytoplasmic calcium flux were observed in neutrophils from cattle persistently infected with BVD virus, compared with noninfected control cattle. Incubation of neutrophils from noninfected controls with rBoIFN gamma significantly (P less than 0.05) decreased random migration under agarose, cytochrome-C reduction, and cytoplasmic calcium flux. Neutrophils from cattle persistently infected with BVD virus also had decreased random migration under agarose after incubation with rBoIFN gamma; in addition, antibody-independent cell-mediated cytotoxicity, elastase release, and cytoplasmic calcium flux were significantly enhanced. The rBoIFN gamma induced significantly (P less than 0.05) different effects on chemotaxis, cytochrome-C reduction, iodination, and cytoplasmic calcium flux of neutrophils from infected and control cattle. The rBoIFN gamma was more effective at improving the function of neutrophils from cattle persistently infected with BVD virus, compared with neutrophils from controls. Lymphocytes from infected cattle had decreased blastogenesis in response to phytohemagglutinin, concanavalin A, and pokeweed mitogen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

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 viral isolate, demonstrated that cells in superinfected cultures contained both viral biotypes. Immunoprecipitation was used to compare the temporal detection of viral induced polypeptides in superinfected cultures to that of cultures infected with a single viral biotype. In single cytopathic viral infections, viral induced polypeptides of 80 kDa and 53-56 kDa are detected simultaneously, but in superinfections a 4 h gap occurred between detection of the 53-56 kDa polypeptide and detection of the 80 kDa polypeptide.

Animals↗

PubMed1990

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 depletion, and paracortical lymphocytic hyperplasia. At necropsy, cytopathic virus was recovered from 4/4 calves and noncytopathic virus was isolated from 2/4 calves. Neutralizing antibodies to noncytopathic bovine viral diarrhea virus were detected in the two calves from which noncytopathic virus was not recovered. Immunohistochemical analysis of lymphoid tissues demonstrated a small, randomly distributed population of mononuclear cells that contained bovine viral diarrhea viral antigen in 7/8 calves.

Animals↗

PubMed1990

Control of bovine virus diarrhoea virus.

Bovine virus diarrhoea (BVD) virus is ubiquitous in cattle populations throughout the world. Strategies for controlling BVD virus infections are continually evolving. Current control procedures are based on identification and elimination of persistently infected cattle, which are a primary source of virus for non-infected cattle, and immunisation with killed or modified live virus vaccines. Additional concerns for control are the possible contamination of semen, embryos and biologicals with virus. In the near future, genetically engineered nucleic acid probes and subunit vaccines containing selected elements of the BVD virus may be available for incorporation into control procedures.

Animals↗

PubMed1990

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. Other viral-induced polypeptides of 115,000, 80,000, 48,000, and 25,000 daltons were precipitated with sera from some vaccinates. Precipitation of those polypeptides was related to the vaccine used. When multiple viral polypeptides were precipitated, the 53,000- to 56,000-dalton polypeptide appeared immunodominant.

Animals↗

PubMed1990

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 antigen were inconclusive for neutrophils, but viral antigen was found in the cytoplasm of mononuclear leukocytes. A distinct and highly pure population of eosinophils was identified during flow cytometric analysis of neutrophil populations from 2 of 9 cattle.

Animals↗

PubMed1989

Specificity of neutralizing and precipitating antibodies induced in healthy calves by monovalent modified-live bovine viral diarrhea virus vaccines.

Serum was obtained at weekly intervals after vaccination of 6 healthy calves with either of 2 commercially available monovalent modified-live bovine viral diarrhea (BVD) virus vaccines. Detectable neutralizing antibodies to each of 10 cytopathic and 10 noncytopathic isolates of BVD virus were produced by 1 or more of the calves by 14 days after vaccination, but no calf produced detectable neutralizing antibodies to all 20 BVD viruses. At that time, precipitating antibodies against viral-induced polypeptides of approximately 115,000; 80,000; 56,000; 48,000; 39,000; and 25,000 daltons were detected in sera from some calves. Also at that time, specificity of the antibodies for polypeptides of certain viruses was detected. At 21 days after vaccination, each calf produced neutralizing antibodies to all 20 BVD viruses. At that time, precipitating antibodies to each of the aforementioned viral induced polypeptides were detected in serum from each calf. Precipitating antibodies to viral induced polypeptides of 61,000 and 37,000 daltons were detected in samples of sera obtained from some calves at 42 days after vaccination.

Animals↗

PubMed1989

Prevalence estimation from pooled samples.

Under certain conditions, prevalence can be estimated by testing samples from individual members or by pooling samples from members into a group and by testing the sample from the group as a single unit. Pooled tests are more accurate than individual tests when P is less than 10%. Optimal group size is 1.6/P. Efficiency decreases slowly with suboptimal size and rapidly with overly large size.

Animals↗

PubMed1988

Viral and viral protein specificity of antibodies induced in cows persistently infected with noncytopathic bovine viral diarrhea virus after vaccination with cytopathic bovine viral diarrhea virus.

Neutralizing and nonneutralizing antibodies to bovine viral diarrhea (BVD) virus were detected in 3 cows persistently infected with noncytopathic BVD virus after vaccination with modified-live cytopathic BVD virus. Neutralizing antibodies detected in serum samples from each persistently infected cow at 3 weeks after vaccination were highly specific for certain isolates of cytopathic BVD virus and reacted only with a viral protein with a molecular weight of 53,000. Neutralizing antibodies to 1 of 3 isolates of noncytopathic BVD virus were detected in a serum sample obtained at 12 weeks after vaccination from 1 of 3 persistently infected cows. Nonneutralizing antibodies were detected in all cows at 7 to 12 weeks after vaccination. The nonneutralizing antibodies were less specific for isolates of BVD virus and reacted with viral proteins with molecular weights of 115,000, 80,000, 53,000, and 47,000.

Animals↗