| continued freedom from bluetongue virus infection in cattle and sheep in western australia south of latitude 26 degrees s. | | 1996 | 8937679 |
| genetically engineered particulate virus-like structures and their use as vaccine delivery systems. | the orbivirus genus within the family reoviridae consists of nonenveloped architecturally complex viruses. the icosahedral viruses are 810 a diameter in size and are comprised of two protein shells containing seven proteins (vp1-vp7), surrounding a genome of ten double-stranded rna segments. the prototype virus, bluetongue virus (btv), is the etiological agent of a disease that can reach epidemic proportions among sheep and cattle. to develop highly protective virus-like particles, we have devel ... | 1996 | 8957671 |
| in vitro susceptibility of goat mononuclear cells to bluetongue virus. | goat peripheral blood mononuclear cells were cultured and their susceptibility to bluetongue virus (btv) serotype 1 was tested. a small number of adherent and non-adherent cells were found positive for btv antigens by immunoperoxidase and immunofluorescence tests. both adherent and non-adherent cells supported limited level of viral replication as evidenced by low titre in the biological assay, thus indicating their susceptibility. | 1996 | 8979494 |
| improved method for counting virus and virus like particles. | an improved method for counting virus and virus like particles by electron microscopy (em) was developed. the procedure involves the determination of the absolute concentration of pure or semi-pure particles once deposited evenly on em grids using either centrifugation or antibody capture techniques. the counting of particles was done with a microfiche unit which enlarged approximately 50 x the image of particles on a developed negative film which had been taken at a relatively low magnification ... | 1996 | 9002073 |
| characterization of jkt-7400, an orbivirus which grows in aedes albopictus mosquito cells: evidence pointing to a minor virion protein, vp6, as the rna guanylyltransferase. | jkt-7400 virus, an orbivirus originally isolated from culex mosquitos, was plaque purified and adapted to aedes albopictus mosquito cells. conditions which enhance viral cytopathic effect and optimize plaque formation are described. in contrast to bluetongue virus, the prototype orbivirus, no replication of jkt-7400 virus in vertebrate cells was observed. the core particle of jkt-7400 virus contains 10 segments of dsrna and three minor proteins, vp1, vp4, and vp6. the inner shell contains two ma ... | 1997 | 9024806 |
| bluetongue virus in laboratory-reared culicoides variipennis sonorensis: applications of dot-blot, elisa, and immunoelectron microscopy. | an avidin-biotin complex (abc) dot-blot, an antigen capture enzyme-linked immunosorbent assay (elisa), and immunoelectron microscopy (iem) were used to detect bluetongue (blu) virus or viral antigen or both in adult culicoides variipennis sonorensis wirth & jones. the dot-blot and elisa procedures detected viral antigen in 10-22% (depending on serotype) of the biting midges infected with blu-2, blu-10, blu-13, and blu-17 and approximately 68% of the midges infected with blu-11. iem analyses reve ... | 1997 | 9086705 |
| applications of dot-blot, elisa, and immunoelectron microscopy to field detection of bluetongue virus in culicoides variipennis sonorensis: an ecological perspective. | an avidin-biotin complex (abc) dot-blot, an antigen capture enzyme-linked immunosorbent assay (elisa), and immunoelectron microscopy (iem) were used to detect bluetongue (blu) virus and viral antigen in field-collected c. varriipennis sonorensis wirth & jones from an enzootic blu area in northeastern colorado. this is the 1st attempt to apply these immunodiagnostic methods to an epidemiologically relevant, large-scale ecological system. one of the 1,800 midges (0.0005%) was positive by the dot-b ... | 1997 | 9086706 |
| prevalence of antibodies to bluetongue, bovine herpesvirus 1 and bovine viral diarrhea/mucosal disease viruses in water buffaloes in minas gerais state, brazil. | a serological survey to detect water buffaloes with antibodies to bluetongue virus (btv), bovine herpesvirus 1 (bhv 1) and bovine viral diarrhea/mucosal disease virus (bvd/mdv) was performed in minas gerais state, brazil. precipitating antibodies against btv were detected by the agar gel immunodiffusion test (agid) in 54.4% of the serum samples tested. microplate serum-neutralization tests revealed that 14.7% and 52.7% of the water buffaloes had antibodies to bhv 1 and bvd/mdv, respectively. the ... | 1996 | 9091990 |
| contamination of genetically engineered chinese hamster ovary cells. | in late 1988, during production of a recombinant protein for phase i clinical trials, a failure of the cell culture production system occurred due to contamination of the cells by an orbivirus [1]. the incident occurred at bioferon gmbh & co, laupheim, germany, a joint venture of biogen, inc., cambridge, ma, and dr. renstschler arzneimittel gmbh & co (bioferon is currently a wholly owned subsidiary of rentschler and is now known as dr. rentschler biotechnologie gmbh). the investigation into, and ... | 1996 | 9119137 |
| abortion and death in pregnant bitches associated with a canine vaccine contaminated with bluetongue virus. | | 1996 | 9119141 |
| stable protein-rna interaction involves the terminal domains of bluetongue virus mrna, but not the terminally conserved sequences. | the interaction of bluetongue virus (btv) proteins with viral rna was investigated in vitro by means of a biochemical approach. by subjecting cytoplasmic extracts from virus-infected baby hamster kidney cells and in vitro synthesized radiolabeled rna to ultraviolet cross-linking assays, we demonstrated that, of all the btv proteins, ns2 becomes most intimately associated with the labeled viral rna. competition binding studies indicated that ns2 has the greatest affinity for the 3' region of the ... | 1997 | 9123855 |
| serologic survey for infectious pathogens in free-ranging american bison. | from november 1991 through march 1992, we evaluated 101 free-ranging american bison (bison bison) from yellowstone national park, wyoming (usa) for exposure to infectious organisms that commonly infect cattle. no titers were detected for bluetongue virus, bovine leukemia virus, or campylobacter fetus in these 101 bison. detectable antibodies occurred against anaplasma marginale (eight of 76, 11%), bovine respiratory syncytial virus (31 of 101, 31%), bovine viral diarrhea (31 of 101, 31%), bovine ... | 1997 | 9131564 |
| pathogen exposure patterns among sympatric populations of bighorn sheep, mule deer and cattle. | we sampled sympatric bighorn sheep (ovis canadensis, n = 31), mule deer (odocoileus hemionus, n = 38), and domestic cattle (n = 26) in the san bernadino mountains of southern california (usa) for the presence of psoroptes spp. mites and for serologic evidence of exposure to bluetongue virus (btv) and babesia spp. from 1991 through 1994, psoroptes spp. infestations were found on 12 (44%) of 27 bighorn sheep. no mites were found on mule deer or cattle. the btv serum antibody prevalence in a cohort ... | 1997 | 9131583 |
| baculovirus-expressed nonstructural protein ns2 of bluetongue virus induces a cytotoxic t-cell response in mice which affords partial protection. | virus-specific cytotoxic t lymphocytes were generated in two strains of mice (balb/c and cba/ca) against baculovirus recombinant proteins (minor and nonstructural) derived from bluetongue virus serotype 10. immunization of mice with recombinant baculovirus insect cell extracts expressing the nonstructural protein ns2 (bac-ns2) conferred partial protection against infection with vaccinia virus expressing the ns2 protein. this protective immunity was mediated by cd8+ cells. in contrast, no protect ... | 1997 | 9144367 |
| characterization of tubular structures composed of nonstructural protein ns1 of african horsesickness virus expressed in insect cells. | the characteristic tubules that are produced during the orbivirus infection cycle are composed of a major viral nonstructural protein, ns1. to characterize the ns1 gene and gene product of african horsesickness virus (ahsv), a full-length cdna copy of the ns1 gene of ahsv-6 was cloned and the nucleotide sequence determined. ns1 was highly conserved within the ahsv serogroup with between 95-98% conservation of amino acids among ns1 of ahsv-6, ahsv-4 and ahsv-9. the structure of ahsv ns1 tubules w ... | 1997 | 9152425 |
| baculovirus multigene expression vectors and their use for understanding the assembly process of architecturally complex virus particles. | the baculovirus expression vector is a eukaryotic dna viral vector for the cloning and expression of foreign genes in cultured lepidopteran insect cells and insects. it has become an important tool for the large-scale production of recombinant proteins for a variety of applications including the structure-function analysis of genes and their gene products. we have developed a number of baculovirus multigene expression vectors and utilized these to understand the assembly process of multicomponen ... | 1997 | 9185857 |
| bluetongue virus detection: a safer reverse-transcriptase polymerase chain reaction for prediction of viremia in sheep. | a reversible target capture viral rna extraction procedure was combined with a reverse-transcriptase nested polymerase chain reaction (pcr) to develop a capture pcr assay providing a rapid and safe prediction method for circulating bluetongue virus in infected ruminants. this new assay was compared with virus isolation and a recently developed antigen-capture enzyme-linked immunosorbent assay (elisa) for the detection of bluetongue virus. eight warhill crossbred sheep were inoculated subcutaneou ... | 1997 | 9211228 |
| cell-mediated immune response and il-2 production in white-tailed deer experimentally infected with hemorrhagic disease viruses. | hemorrhagic disease, caused by various serotypes of two closely related orbivirus serogroups, the epizootic hemorrhagic disease viruses (ehdv) and the bluetongue viruses (btv), is a major cause of morbidity and mortality in white-tailed deer (wtd) in the united states. despite the importance of hemorrhagic disease in wtd, little is known about host defense mechanisms triggered by infection with either causative virus or how that immune response is modulated by challenge with closely related orbi ... | 1997 | 9223232 |
| vp7: an attachment protein of bluetongue virus for cellular receptors in culicoides variipennis. | the importance of vp7 of bluetongue virus (btv) in the binding of btv to membrane proteins of the btv vector culicoides variipennis was investigated. core btv particles, prepared from whole viruses, lacked outer proteins vp2 and vp5 and had vp7 exposed. more core particles and whole viruses bound to membrane preparations of adults of c. variipennis and kc cells, which were cultured from this vector insect, than to membrane preparations of manduca sexta larvae. more core particles than whole viru ... | 1997 | 9225038 |
| [seroprevalence of viral infections in llamas (lama glama) in the republic of argentina]. | this study reports the seroprevalence of bovine viral infections in llamas (lama glama) in argentina. this is the first study made in the country including 390 llamas and testing antibodies against eight viruses. samples were collected from nine farms distributed in three different provinces: buenos aires, córdoba and jujuy. the samples were tested for antibodies against eight viruses known to infect cattle: bovine herpesvirus type 1 (bhv-1), bovine viral diarrhea virus (bvdv), bovine adenovirus ... | 1997 | 9229724 |
| bluetongue virus seropositivity in sheep flocks in north west frontier province, pakistan. | the objectives of this study were to describe the prevalence and distribution of serum antibodies to bluetongue virus (btv) in a sample of 38 sheep flocks in northern areas of the north west frontier province of pakistan and to identify demographic and productivity variables that are associated with btv seropositivity. blood samples were taken from a random sample of ewes in each flock in april 1995. the owners of the flocks were interviewed regarding some demographic, husbandry and productivity ... | 1997 | 9234437 |
| simulation analysis of the effect of herd immunity and age structure on infection of a cattle herd with bluetongue viruses in queensland, australia. | a state-transition model based on leslie matrix formulation was used to investigate the effects of herd immunity and age structure on the infection of a simulated cattle herd with bluetongue viruses under australian climatic conditions. increasing duration of immunity decreased the prevalence of infection. a duration of immunity of 33 months was consistent with prevalence estimates made from previous serological studies of bluetongue virus. herd prevalence displayed slowly dampening cyclical var ... | 1997 | 9234438 |
| testicular atrophy in a mule deer population. | monitoring mule deer (odocoileus hemionus) on a former plutonium production site along the columbia river at the hanford site, washington (usa) revealed 27 (23%) of 116 adult males had unusually shaped, velvet-covered antlers and abnormally developed testicles. we captured 32 males to examine age-class differences and the ratio of affected to unaffected deer and determine whether affected testicles were atrophic or hypoplastic. we found testicular atrophy in most deer with velvet-covered antlers ... | 1997 | 9249686 |
| in vitro replication of epizootic hemorrhagic disease and bluetongue viruses in white-tailed deer peripheral blood mononuclear cells and virus-cell association during in vivo infections. | in vitro and in vivo infections were conducted to determine if the epizootic hemorrhagic disease (ehd) and bluetongue (bt) viruses would replicate in peripheral blood mononuclear (pbm) cells of white-tailed deer (odocoileus virginianus). all of the north american ehd and bt viruses (ehd virus serotypes 1 and 2, and bt virus serotypes 2, 10, 11, 13, and 17) replicated in vitro in cultures of white-tailed deer pbm cells. however, this replication appeared to be monocyte-dependent and was not enhan ... | 1997 | 9249704 |
| host defense responses associated with experimental hemorrhagic disease in white-tailed deer. | our objectives were to examine the immunity conferred by epizootic hemorrhagic disease virus serotype 2 (ehdv-2) infection in white-tailed deer (odocoileus virginianus) and determine if this immunity was protective during challenge with homologous (ehdv-2) or heterologous (bluetongue virus serotype 10; btv-10) virus. trials were conducted in the fall of 1992 and 1993. in the first experiment, naive white-tailed deer were infected intradermally and subcutaneously with ehdv-2 and monitored via phy ... | 1997 | 9249705 |
| an atomic model of the outer layer of the bluetongue virus core derived from x-ray crystallography and electron cryomicroscopy. | bluetongue virus (btv), which belongs to the reoviridae family and orbivirus genus, is a non-enveloped, icosahedral, double-stranded rna virus. several protein layers enclose its genome; upon cell entry the outer layer is stripped away leaving a core, the surface of which is composed of vp7. the structure of the trimeric vp7 molecule has previously been determined using x-ray crystallography. the articulated vp7 subunit consists of two domains, one which is largely alpha-helical and the other, s ... | 1997 | 9261080 |
| structures of orbivirus vp7: implications for the role of this protein in the viral life cycle. | bluetongue virus (btv) is the prototypical virus of the genus orbivirus in the family reoviridae and causes an economically important disease in domesticated animals, such as sheep. btv is larger and more complex than any virus for which comprehensive atomic level structural information is available. its capsid is made primarily from four structural proteins two of which, vp3 and vp7, form a core which remains intact as the virus penetrates the host cell. each core particle contains 780 copies o ... | 1997 | 9261081 |
| serogrouping and topotyping of sudanese and united states strains of epizootic hemorrhagic disease virus using pcr. | the potential use of the recently reported polymerase chain reaction (pcr) protocol for detection of united states epizootic hemorrhagic disease virus (ehdv) serotype 1 (ehdv-1) and serotype 2 (ehdv-2) ribonucleic acid in cell culture and clinical specimens was evaluated for detection of sudanese ehdv strains. ehdv serotype 5 (ehdv-5) and ehdv, isolate 318 (untyped) designated (ehdv-318), recovered from sentinel calves at the khartoum university farm (sudan) were studied. rna from ehdv-5 and ehd ... | 1997 | 9280388 |
| the role of cell-mediated immunity in the pathogenesis of bluetongue virus serotype 11 in the experimental infection of vaccine/sensitized calves. | the cellular immune response of cattle to virulent and avirulent (inactivated) bluetongue virus (btv) was studied. each of three calves received three vaccinations (sensitizations) with binary ethyleneimine (bei)-inactivated btv, 3 weeks apart. the sensitized animals were challenged with btv-11 strain uc8 3 weeks after the last vaccination. btv-seropositive and btv-seronegative calves were used as controls. the animals were bled weekly for virus isolation and for evidence of cell-mediated immuni ... | 1997 | 9280389 |
| structure of broadhaven virus by cryoelectron microscopy: correlation of structural and antigenic properties of broadhaven virus and bluetongue virus outer capsid proteins. | the three-dimensional structure of broadhaven virus (brdv) has been determined to 23 a resolution by cryoelectron microscopy and image processing. as predicted from sequence homology, the brdv structure resembles that of bluetongue virus (btv) with the notable exception of one of the outer shell proteins. the cores of brdv and btv are identical at medium resolution; they have a diameter of 710 a and the vp7 trimers are arranged on a t = 13 icosahedral lattice. the outer shell proteins, vp5 of br ... | 1997 | 9281498 |
| brightness speeds search for structures great and small. | | 1997 | 9297237 |
| identification of a salivary vasodilator in the primary north american vector of bluetongue viruses, culicoides variipennis. | several species of culicoides biting midges are important pests and vectors of pathogens affecting humans and other animals. bluetongue is the most economically important arthropod-borne animal disease in the united states. culicoides variipennis is the primary north american vector of the bluetongue viruses. a reddish halo surrounding a petechial hemorrhage was noticed at the site of c. variipennis blood feeding in previously unexposed sheep and rabbits. salivary gland extracts of nonblood-fed ... | 1997 | 9311653 |
| bluetongue virus vp6 protein binds atp and exhibits an rna-dependent atpase function and a helicase activity that catalyze the unwinding of double-stranded rna substrates. | rna-dependent atpase and helicase activities have been identified associated with the purified vp6 protein of bluetongue virus, a member of the orbivirus genus of double-stranded rna (dsrna; reoviridae family) viruses. in addition, the protein has an atp binding activity. rna unwinding of duplexes occurred with both 3' and 5' overhang templates, as well as with blunt-ended dsrna, an activity not previously identified in other viral helicases. although little sequence similarity to other helicase ... | 1997 | 9311795 |
| projection structure of vp6, the rotavirus inner capsid protein, and comparison with bluetongue vp7. | the rotavirus nucleocapsid protein (vp6) is the major structural protein of inner capsid particles (icp). vp6 is essential for rna transcription and binds to a virally encoded glycoprotein receptor (nsp4) involved in the rotavirus assembly pathway. to explore the structure of vp6, two-dimensional (2d) crystals of vp6 were generated and examined by electron microscopy and image processing. fourier transforms computed from low-dose images of negatively stained 2d vp6 crystals displayed complete da ... | 1997 | 9325096 |
| efficacy of vaporized hydrogen peroxide against exotic animal viruses. | the efficacy of vapor-phase hydrogen peroxide in a pass-through box for the decontamination of equipment and inanimate materials potentially contaminated with exotic animal viruses was evaluated. tests were conducted with a variety of viral agents, which included representatives of several virus families (orthomyxoviridae, reoviridae, flaviviridae, paramyxoviridae, herpesviridae, picornaviridae, caliciviridae, and rhabdoviridae) from both avian and mammalian species, with particular emphasis on ... | 1997 | 9327555 |
| antibodies against some viruses of domestic animals in southern african wild animals. | twenty-four species of south african wild animals were tested for the presence of antibodies against the viruses of 16 common diseases of domestic animals. positive results were obtained for african horsesickness, equine encephalosis, equid herpes virus-1, infectious bovine rhinotracheitis, allerton disease (herpes mammillitis), lumpy skin disease, parainfluenza, encephalomyocarditis, bluetongue, wesselsbron disease, bovine ephemeral fever, and akabane disease complex. no antibodies could be dem ... | 1997 | 9352558 |
| effect of bovine herpes virus-1, bluetongue virus and akabane virus on the in vitro development of bovine embryos. | bovine oocytes enclosed by follicular epithelial (fe) cells were exposed to bovine herpes virus-1 (bhv-1), bluetongue virus (btv) and akabane virus (av), matured in culture for 24 h and then in vitro fertilized. in the bhv-1-exposed group, bhv-1 was isolated from medium 3 days after in vitro fertilization at a high titer, and a severe cytopathic effect was observed in the fe cells. oocytes in the bhv-1-exposed group developed to the 2-cell to 8-cell stage, but failed to develop into blastocysts. ... | 1997 | 9355248 |
| effects of domain-switching and site-directed mutagenesis on the properties and functions of the vp7 proteins of two orbiviruses. | based on the crystal structure of the vp7 major core protein of bluetongue virus serotype 10 (btv-10) and that of the top domain of the vp7 protein of african horsesickness virus serotype 4 (ahsv-4), chimeras and site-directed mutants of the proteins were constructed and the products analyzed with respect to their properties and functions. chimeras with the central upper domain of btv-10 vp7 replaced by that of ahsv-4 vp7 (construct bab) formed trimers, as did the converse construct (aba). furth ... | 1997 | 9356334 |
| monitoring of culicoides spp. at a site enzootic for hemorrhagic disease in white-tailed deer in georgia, usa. | biting midges of the genus culicoides (diptera: ceratopogonidae) were monitored at a georgia (usa) site where epizootic hemorrhagic disease (ehd) and bluetongue (bt) viruses are enzootic among white-tailed deer (odocoileus virginianus). collections were made using a captive white-tailed deer and light traps from june 1993 through november 1994. we collected 210,482 females from the captive deer during morning and evening periods. predominant species were c. lahillei (73%), c. stellifer (16%), c. ... | 1996 | 9359063 |
| hemorrhagic disease in white-tailed deer in texas: a case for enzootic stability. | although antibodies to viruses in both the epizootic hemorrhagic disease virus (ehdv) and bluetongue virus (btv) sero-groups have been reported from white-tailed deer (odocoileus virginianus) in texas (usa), there are few reports of hemorrhagic disease (hd) in these populations. to understand the extent and diversity of exposure to the north american ehdv and btv serotypes in these deer populations, we serologically tested 685 white-tailed deer collected from november 1991 through march 1992 thr ... | 1996 | 9359074 |
| internal image rabbit anti-idiotypic antibody detects sheep antibodies to the bluetongue virus core protein vp7. | rabbit polyclonal anti-idiotypic antibodies (anti-id) were generated against three murine monoclonal antibodies (mabs) specific for the group-specific antigen vp7 of bluetongue virus (btv) by the sequential immunization method. it was demonstrated by serological tests that part of the anti-id possesses the characteristics of internal image anti-id. by affinity purification against the individual mabs, the internal image anti-id, designated rab2-a, was isolated and identified as specific for the ... | 1995 | 9373343 |
| identification of an antigenic peptide specific for bluetongue virus using phage display expression of ns1 sequences. | ns1 is a non-structural protein associated with the replication of bluetongue virus (btv), an orbivirus (reoviridae) that infects sheep and cattle. ns1 is potentially useful as a diagnostic antigen since the presence of specific antibodies is an indication that the virus has replicated in the host. it is, however, not antigenically unique and cross-reacts serologically with the analogous protein of the related epizootic haemorrhagic disease virus (ehdv). | 1995 | 9373350 |
| histamine and eicosanoid levels in plasma and peripheral blood leucocyte cultures during experimental infection of cattle with bluetongue virus serotype 11. | three calves were sensitized with three doses of inactivated btv-11 uc8 strain and then experimentally infected with the homologous virus. in addition, four btv-seronegative heifers were also experimentally infected with btv-11. granulocyte rich fractions of peripheral blood leucocyte (pbl-grf) cultures from btv-sensitized/infected calves and from control unexposed cattle were exposed in vitro with btv-11. histamine, leukotriene (lt) c4 and prostaglandin (pg) d2 were assayed in supernatant fluid ... | 1997 | 9394610 |
| association between risk of seroconversion of sentinel cattle to bluetongue viruses and culicoides species (diptera: ceratopogonidae) in queensland, australia. | the association between risk of seroconversion of sentinel cattle to bluetongue viruses and the number of culicoides brevitarsis kieffer and c. wadai kitaoka caught by light traps was investigated using survival analysis. eight sentinel herds that seroconverted to bluetongue viruses between 1990 and 1994, and for which insect-trapping data were available, were selected for inclusion in the study. these herds were located at six sites along the eastern coast of queensland, australia, from approxi ... | 1997 | 9443333 |
| antibody responses and protective immunity to recombinant vaccinia virus-expressed bluetongue virus antigens. | the role of individual viral proteins in the immune response to bluetongue virus (btv) is not clearly understood. to investigate the contributions of the outer capsid proteins, vp2 and vp5, and possible interactions between them, these proteins were expressed from recombinant vaccinia viruses either as individual proteins or together in double recombinants, or with the core protein vp7 in a triple recombinant. comparison of the immunogenicity of the vaccinia expressed proteins with btv expressed ... | 1997 | 9477479 |
| sequential distribution of neurovirulent and avirulent strains of bluetongue virus in neonatal mice by rt-pcr. | neurotropism of bluetongue virus (blu) has been demonstrated in the developing brain of fetal ruminants and neonatal mouse models. two strains of blu serotype 11, uc8 and uc2, differentiated by their electrophoretic characteristics and abilities to cause brain lesions in bovine fetuses and neonatal mice were investigated to determine differences in tissue distribution in new born mice following subcutaneous inoculation. tissue analysis by reverse transcriptase-polymerase chain reaction (rt-pcr) ... | 1998 | 9505972 |
| a leucine zipper-like domain is essential for dimerization and encapsidation of bluetongue virus nucleocapsid protein vp4. | the bluetongue virus (btv) minor protein vp4, with molecular mass of 76 kda, is one of the seven structural proteins and is located within the inner capsid of the virion. the protein has a putative leucine zipper near the carboxy terminus of the protein. in this study, we have investigated the functional activity of this putative leucine zipper by a number of approaches. the putative leucine zipper region (amino acids [aa] 523 to 551) was expressed initially as a fusion protein by using the pmal ... | 1998 | 9525620 |
| membrane organization of bluetongue virus nonstructural glycoprotein ns3. | the smallest rna segment (s10) of bluetongue virus (an orbivirus, family reoviridae) encodes two closely related nonstructural proteins, the 229-amino-acid (aa) ns3 and the 216-aa ns3a. the proteins are found in glycosylated and nonglycosylated forms in infected cells (x. wu, h. iwata, s.-y. chen, r. w. compans and p. roy j. virol. 66:7104-7112, 1992). the ns3/ns3a proteins have two hydrophobic domains (aa 118 to 141 and 162 to 182) and two potential asparagine-linked glycosylation sites (aa 63 ... | 1998 | 9525663 |
| a nested pcr for detection of north american isolates of bluetongue virus based on ns1 genome sequence analysis of btv-17. | a nested polymerase chain reaction (pcr)-based assay, for detection of bluetongue virus (btv) ribonucleic acid in cell culture and tissue samples, was developed. two pairs of oligonucleotide primers (btv1 and btv4 and btv2 and btv3), selected from non-structural protein 1 (ns1) gene of btv-17, were used for the nested pcr in two amplification steps. first a 826-bp product was amplified using an outer primer pair btv1 and btv4. the second amplification, using nested or internal primer pair btv2 a ... | 1998 | 9549851 |
| seasonal abundance and parity of stock-associated culicoides species (diptera: ceratopogonidae) in different climatic regions in southern africa in relation to their viral vector potential. | seasonal abundance and parity in culicoides populations, in the vicinity of livestock, were determined at seven sites in five different climatic regions with 220 v down-draught blacklight-traps. in 418 collections made between october 1983 and december 1986, a total of 2,134,171 culicoides, of which 342,571 were identified to species level and sexed, were collected; 267 of these collections (182,321 culicoides) were graded for parity. in the frost-free summer rainfall area, culicoides were colle ... | 1997 | 9551477 |
| toxorhynchites-fluorescent antibody system for the detection of bluetongue virus from culicoides midges (diptera: ceratopogonidae). | a new system, the toxorhynchites-fluorescent antibody (tfa) test in which the larvae of toxorhynchites splendens mosquitoes were used for the detection of bluetongue virus (btv) from culicoides midges, was developed. twenty-seven pools of culicoides midges were collected from bluetongue-prone areas of tamil nadu by use of the light-trap and suction-trap methods. a suspension of each pool was injected intrathoracically into t. splendens iv instar larvae and inoculated onto vero cell monolayers. a ... | 1997 | 9551482 |
| abattoir survey of sheep and goats in the gambia. | an abattoir survey of sheep and goats was carried out in the gambia for one year. a total of 1248 goats and 438 sheep, predominantly young females, were slaughtered and sampled. sixty per cent of the females of both species were pregnant. there were no significant differences between the dressing percentages of different breeds and age groups. sex and stage of pregnancy had a significant influence on carcase yields in both species. in goats the highest carcase yields were obtained during the ear ... | 1998 | 9569483 |
| sequence and cognitive analyses of two virulence-associated markers of bluetongue virus serotype 17. | genome segments 2 and 3 were completely sequenced for one virulent and one avirulent bluetongue serotype 17 (blu-17). these two segments were previously shown to exhibit virulence-associated markers. the marker on segment 2 was characterized as a change in the neutralization domain on its protein product, vp2. the nucleotide sequences for segments 2 were 94.5% identical, and their predicted proteins differed by 34 amino acids or 3.7%. three clusters of variability were identified which may be in ... | 1997 | 9612723 |
| the complete sequence of four major structural proteins of african horse sickness virus serotype 6: evolutionary relationships within and between the orbiviruses. | the amino acid sequences of four major capsid proteins of african horse sickness virus (serotype 6, ahsv-6) have been determined from analyses of cdna clones representing the l2, l3, m6 and s7 rna segments. the ahsv-6 l3 rna segment has an open reading frame of 2715 base pairs and encodes the inner capsid protein vp3 which comprises 905 amino acids. the vp3 layer forms the subcore of the virion and is surrounded by the vp7 protein which is encoded by the s7 gene. the ahsv-6 s7 gene was found to ... | 1998 | 9617769 |
| the effects of pharmacological and lentivirus-induced immune suppression on orbivirus pathogenesis: assessment of virus burden in blood monocytes and tissues by reverse transcription-in situ pcr. | we investigated the effects of pharmacological and lentivirus-induced immunosuppression on bluetongue virus (btv) pathogenesis as a mechanism for virus persistence and induction of clinical disease. immunologically normal and immunosuppressed sheep were infected subcutaneously with btv serotype 3 (btv-3), a foreign isolate with unknown pathogenicity in north american livestock, and with north american serotype 11 (btv-11). erythrocyte-associated btv rna was detected earlier and at greater concen ... | 1998 | 9621018 |
| provide a context for disease emergence. | | 1998 | 9621214 |
| culicoides in relation to transmission of african horse sickness virus in the gambia. | twelve light trap collections made near overnight shelters of horses and donkeys in four villages in the central river division of the gambia captured fourteen species of biting midge of the genus culicoides. five species new to the gambia were identified. this brought the number of recognized species of culicoides (after a revision of c. schultzei) to twenty-nine in the gambia. species known or suspected as vectors of african horse sickness virus (ahsv) and bluetongue virus (btv) comprised 83% ... | 1998 | 9622369 |
| the use of lectin-dependent lysis for detection of cytotoxic t lymphocytes in outbred animals. | the assessment of cytotoxic t lymphocyte (ctl) specificity and levels of activity is often important in the analysis of an immune response to viral infection or vaccination. however, the restriction of ctl lysis to cells bearing self major histocompatibility complex proteins makes this analysis difficult in outbred animals. the data presented here demonstrate that lysis by ctl can be measured on allogeneic or xenogeneic target cells in the presence of concanavalin a, if the ctl are first restimu ... | 1998 | 9671129 |
| guanylyltransferase and rna 5'-triphosphatase activities of the purified expressed vp4 protein of bluetongue virus. | we have examined the rna-capping enzyme activities of bluetongue virus (btv) minor core protein, vp4. recombinant btv vp4 protein was purified to homogeneity from insect cell culture infected with a baculovirus vp4 of btv serotype 10. we demonstrate that the purified protein, and vp4 encapsidated in core-like particles, react with gtp and covalently bind gmp via a phosphoamide linkage, a characteristic feature of guanylyltransferase enzyme. vp4 also catalyses a gtp-ppi exchange reaction indicati ... | 1998 | 9671555 |
| evaluation of bluetongue virus diagnostic tests in free-ranging bighorn sheep. | five bluetongue virus (btv) diagnostic tests were evaluated for use in free-ranging bighorn sheep. we sampled one bighorn sheep population four times between 1989 and 1995. the tests evaluated included virus isolation (vi), polymerase-chain reaction (pcr), serum neutralization (sn), agar-gel immunodiffusion (agid), and competitive enzyme-linked immunosorbent assay (c-elisa). the c-elisa, agid and sn tests had high levels of agreement in determining serogroup exposure in bighorn sheep. we used ma ... | 1998 | 9689659 |
| pcr detection of north american and central african isolates of epizootic hemorrhagic disease virus (ehdv) based on genome segment 10 of ehdv serotype 1. | pcr amplification technology for the detection of epizootic hemorrhagic disease virus (ehdv) ribonucleic acid in cell culture and clinical specimens was developed. with oligoribonucleotide primers selected from genome segment 10 of ehdv serotype 1 (ehdv-1), which codes for two nonstructural proteins (ns3 and ns3a), the pcr-based assay resulted in a 535-bp pcr product. rnas from north american ehdv-1 prototype, ehdv-2 prototype, and a number of ehdv field isolates, including the central african i ... | 1998 | 9705400 |
| seroprevalence of selected disease agents from free-ranging black bears in florida. | sera obtained from 66 free-ranging florida black bears (ursus americanus floridanus) from three geographic areas of florida (usa) between november 1993 and august 1995 were tested for antibodies to 13 disease agents. antibody prevalences were 3 positive of 37 tested (8%) coxiella burnetti, 37 of 66 (56%) toxoplasma gondii, 3 of 61 (5%) bluetongue virus/epizootic hemorrhagic disease virus (btv/ehdv), 4 of 66 (6%) canine adenovirus-type 1, 5 of 66 (8%) canine distemper virus (cdv), 10 of 62 (16%) ... | 1998 | 9706572 |
| phylogenetic analysis of the s10 gene of field and laboratory strains of bluetongue virus from the united states. | the sequence of the s10 gene segment of the united states prototype strains of btv serotypes 10, 11, 13, and 17 obtained from the american type culture collection (atcc), the commercial modified live virus vaccine strains of btv serotypes 10, 11, and 17, and 20 field isolates of btv serotypes 10, 11, 13, and 17 was determined to better define the molecular epidemiology of btv infection in the us. all s10 gene segments were 822 nucleotides in length with two in-frame initiation codons (nucleotide ... | 1998 | 9712508 |
| health evaluation of free-ranging guanaco (lama guanicoe). | twenty free-ranging guanaco (lama guanicoe) in chubut province, argentina, were immobilized for health evaluations. all but two animals appeared to be in good condition. hematology, serum chemistry, and vitamin and mineral levels were measured, and feces were evaluated for parasites. serology tests included bluetongue, brucellosis, bovine respiratory syncitial virus, bovine viral diarrhea/mucosal disease, equine herpesvirus 1, infectious bovine rhinotracheitis, johne's disease (mycobacterium par ... | 1998 | 9732026 |
| selection of an scfv phage antibody that recognizes bluetongue virus from a large synthetic library and its use in elisas to detect viral antigen and antibodies. | a filamentous phage library displaying a vast repertoire of synthetic single chain fragment variable (scfv) antibody fragments was subjected to affinity selection on purified bluetongue virus (btv) particles. after four rounds of selection and amplification, 73 out of a total of 90 fusion phage clones tested were found to bind to purified btv in elisa. one of these, the clone producing the highest elisa signal, was selected for an investigation of its potential as an immunodiagnostic reagent. th ... | 1998 | 9741056 |
| structure of double-shelled rice dwarf virus. | rice dwarf virus (rdv), a member of the reoviridae family, is a double-stranded rna virus. infection of rice plants with rdv reduces crop production significantly and can pose a major economic threat to southeast asia. a 25-a three-dimensional structure of the 700-a-diameter rdv capsid has been determined by 400-kv electron cryomicroscopy and computer reconstruction. the structure revealed two distinctive icosahedral shells: a t=13l outer icosahedral shell composed of 260 trimeric clusters of p8 ... | 1998 | 9765392 |
| bluetongue research in china. | | 1998 | 9770771 |
| the atomic structure of the bluetongue virus core. | the structure of the core particle of bluetongue virus has been determined by x-ray crystallography at a resolution approaching 3.5 a. this transcriptionally active compartment, 700 a in diameter, represents the largest molecular structure determined in such detail. the atomic structure indicates how approximately 1,000 protein components self-assemble, using both the classical mechanism of quasi-equivalent contacts, which are achieved through triangulation, and a different method, which we term ... | 1998 | 9774103 |
| culicoides variipennis (diptera: ceratopogonidae) complex in virginia. | immature culicoides variipennis (coquillett) were sampled from aquatic habitats throughout virginia, reared to adults, and examined by isozyme electrophoresis to assess their taxonomic status. data from 22 counties showed that c. v. variipennis is widespread and common, the predominant taxon throughout virginia, and genetically similar to c. v. variipennis in maryland. because c. v. variipennis is considered an inefficient vector of the bluetongue viruses, this observation is consistent with the ... | 1998 | 9775615 |
| bluetongue virus core protein vp4 has nucleoside triphosphate phosphohydrolase activity. | the intact virion of bluetongue virus comprises ten segments of dsrna enclosed in two concentric protein capsids. the core, which is transcriptionally active, includes three minor proteins (vp1, vp4 and vp6) which are considered to be the candidates for the core-associated enzymes that transcribe and modify full-length mrna copies for each of the ten genome segments. using purified recombinant vp4 protein and core-like particles containing vp4, in this report it is demonstrated that vp4 has nucl ... | 1998 | 9780054 |
| biggest virus molecular structure yet! | | 1998 | 9783739 |
| new generation of african horse sickness virus vaccines based on structural and molecular studies of the virus particles. | african horse sickness virus (ahsv) is a member of the genus orbivirus, which also includes bluetongue virus (btv) and epizootic haemorrhagic disease (ehdv) virus. these orbiviruses have similar morphological and biochemical properties, with distinctive pathobiological properties and host ranges. sequencing studies of the capsid proteins have revealed evolutionary relationships between these viruses. biochemical studies of the viruses together with the expression of individual proteins and prote ... | 1998 | 9785506 |
| structural studies of orbivirus particles. | we are using crystallographic methods to investigate the structure of ahsv and btv. our initial approach was to investigate the structure of the major protein component of the viral core, vp7(t13). this trimeric protein has been studied in several crystal forms from both orbiviruses and reveals a structure made up of conserved domains, capable of conformational changes and possessing a cleavage site. further crystallographic analyses of native particles have provided a picture of the vp7(t13) an ... | 1998 | 9785510 |
| characterization of two african horse sickness virus nonstructural proteins, ns1 and ns3. | each of the ten segments of the african horse sickness virus (ahsv) genome encodes at least one viral polypeptide. this report focuses on the nonstructural proteins ns1 and ns3, which are encoded by genome segments 5 and 10 respectively. the ns1 protein assembles into tubular structures, which are characteristically produced during orbivirus replication in infected cells. ns1 expressed by a recombinant baculovirus in sf9 cells also forms tubules, which were analysed electron microscopically. the ... | 1998 | 9785511 |
| phylogenetic analysis of african horse sickness virus segment 10: sequence variation, virulence characteristics and cell exit. | african horse sickness virus (ahsv) genome segment 10 encodes the non-structural proteins ns3/ns3a, which is involved in release of virus from cells. full length segment 10 cdnas were amplified by reverse transcription-polymerase chain reaction, from isolates of ahsv serotypes 2, 3, 4, 5, 7, 8 and 9. these cdnas were cloned, sequenced and their phylogenetic relationships analysed. high levels of sequence homology were detected in segment 10 from some isolates of different serotypes, confirming t ... | 1998 | 9785513 |
| use of reverse transcriptase-polymerase chain reaction (rt-pcr) and dot-blot hybridisation for the detection and identification of african horse sickness virus nucleic acids. | a coupled reverse transcriptase-polymerase chain reaction assay (rt-pcr) for the detection of african horse sickness virus (ahsv) dsrna, has been developed using genome segment 7 as the target template for primers. rna from isolates of all nine ahsv serotypes were readily detected. the potential inhibitory effects of either ethylene diamine tetra acetic acid (edta) or heparin on the rt-pcr were eliminated by washing blood samples before lysis of the red blood cells and storage. there was a close ... | 1998 | 9785517 |
| rice ragged stunt oryzavirus genome segment s4 could encode an rna dependent rna polymerase and a second protein of unknown function. | the complete nucleotide sequence of genome segment s4 of rice ragged stunt oryzavirus (rrsv, thai-isolate) was determined. the 3823 bp sequence contains two large open reading frames (orfs). orf1, spanning nucleotides 12 to 3776, is capable of encoding a protein of m(r) 141,380 (p4a). the p4a amino acid sequence predicted from the nucleotide sequence contains sequence motifs conserved in rna-dependent rna polymerases (rdrps). when compared for evolutionary relationships with rdrps of other reovi ... | 1998 | 9787664 |
| bluetongue virus serotypes 1 and 3 infection in poll dorset sheep. | to study the clinical signs following bluetongue virus serotypes 1 and 3 infection in poll dorset sheep. | 1998 | 9791715 |
| some epidemiological and economic aspects of a bluetongue-like disease in cattle in south africa--1995/96 and 1997. | in december 1995 to march 1996 and the early summer of 1997 south africa experienced above average rainfall which favoured the occurrence of culicoides transmitted diseases. during this period several outbreaks of an uncommon disease of cattle occurred over a large part of the country. the clinical signs were similar to those of infection with the viruses of bluetongue (bt) and epizootic haemorrhagic disease of deer (ehd). virus isolation from cattle and culicoides yielded both viruses. dual inf ... | 1998 | 9809318 |
| capping and methylation of mrna by purified recombinant vp4 protein of bluetongue virus. | the core of bluetongue virus (btv) is a multienzyme complex composed of two major proteins (vp7 and vp3) and three minor proteins (vp1, vp4, and vp6) in addition to the viral genome. the core is transcriptionally active and produces capped mrna from which all btv proteins are translated, but the relative role of each core component in the overall reaction process remains unclear. previously we showed that the 76-kda vp4 protein possesses guanylyltransferase activity, a necessary part of the rna ... | 1998 | 9811835 |
| rapid screening of embryonated chicken eggs for bluetongue virus infection with an antigen capture enzyme linked immunosorbent assay. | the sensitivity and specificity of an antigen capture elisa have been compared with virus isolation in cell culture. bluetongue virus (blu) (serotype 23) from the blood of a sheep was titrated by inoculating embryonated chicken eggs (eces) and detecting viral antigen in chicken embryo livers using an antigen capture enzyme linked immunosorbent assay (elisa) (stanislawek et al., 1996. detection by elisa of bluetongue antigen directly in the blood of experimentally infected sheep. vet. microbiol. ... | 1998 | 9820573 |
| vector competence of culicoides bolitinos and c. imicola for south african bluetongue virus serotypes 1, 3 and 4. | the susceptibility of field-collected culicoides bolitinos to infection by oral ingestion of bluetongue virus serotypes 1, 3 and 4 (blu 1, 3 and 4) was compared with that of field-collected c. imicola and laboratory reared c. variipennis sonorensis. the concentration of the virus per millilitre of bloodmeal was 10(5.0) and 10(6.0)tcid50 for blu 4 and 10(7.2)tcid50 for blu 1 and 3. of 4927 c. bolitinos and 9585 c. imicola fed, 386 and 287 individual midges survived 10 days extrinsic incubation, r ... | 1998 | 9824821 |
| the prevalence of antibody to the viruses of bovine virus diarrhoea, bovine herpes virus 1, rift valley fever, ephemeral fever and bluetongue and to leptospira sp in free-ranging wildlife in zimbabwe. | the prevalence of antibody to the viruses of bovine virus diarrhoea (bvd), bovine herpes virus typel (bhv1), rift valley fever (rvf), bovine ephemeral fever (bef) and bluetongue (bt) and to leptospira sp. was determined in wildlife populations in zimbabwe. evidence of infection with bvd virus was found in 14 of the 16 species examined but was greatest in eland taurotragus oryx, nyala tragelaphus angasi and bushbuck tragelaphus scriptus. persistent infection with bvd virus was found in 1 of 303 a ... | 1998 | 9825798 |
| induction of t cell response by bluetongue virus core-like particles expressing a t cell epitope of the m1 protein of influenza a virus. | a cd4+ t cell epitope of the influenza virus matrix protein corresponding to the c terminus (qayqkrmgvqmqrfk) was inserted into the vp7 gene of bluetongue virus (btv). the chimeric protein was expressed by a dual recombinant autographa californica polyhedrosis virus (acnpv), which encodes the two inner capsid proteins vp3 and vp7 of btv. when spodoptera frugiperda cells (sf9 cells) were infected with this recombinant btv, core-like particles (clps) were formed as demonstrated by electron microsc ... | 1998 | 9832322 |
| bovine torovirus: sequencing of the structural genes and expression of the nucleocapsid protein of breda virus. | breda virus (brv), a member of the genus torovirus, is an established etiological agent of diarrhea of cattle, which is found as two separate serotypes, brv-1 and brv-2. in this study, a 7.5 kb fragment of the brv-1 genome that bracketed the genes for the structural proteins of brv was amplified by long rt-pcr and the amplicon purified and sequenced directly. sequence analysis revealed the presence of four open reading frames (orf) corresponding to the peplomer (s), envelope (m), and nucleocapsi ... | 1998 | 9879765 |
| molecular characterization of double-stranded rna segments encoding the major capsid proteins of a palyam serogroup orbivirus that caused an epizootic of congenital abnormalities in cattle. | cdna cloning of the double-stranded rna genome of chuzan virus, a member of the palyam serogroup orbiviruses, was carried out and the complete nucleotide sequences of rna segments 2, 3, 6 and 7, encoding the major capsid proteins vp2, vp3, vp5 and vp7, respectively, were determined. the individual segments had single open reading frames and short inverted repeats adjacent to the conserved terminal sequences. comparative sequence analysis with other serogroups of the genus orbivirus suggested tha ... | 1999 | 9934703 |
| ige responses to bluetongue virus (btv) serotype 11 after immunization with inactivated btv and challenge infection. | to test the hypothesis that development of a btv-specific ige response plays a role in clinical disease manifestation, the humoral immune response of cattle to inactivated and virulent btv was studied. three calves received three sensitizing immunizations of inactivated btv, 3 weeks apart. the btv-sensitized animals, two non-sensitized btv-seropositive and 4 btv-seronegative control cattle. were challenge-exposed with btv-11, uc8 strain. all cattle inoculated with inactivated btv developed group ... | 1999 | 10051184 |
| duration of bluetongue viraemia and serological responses in experimentally infected european breeds of sheep and goats. | the duration of viraemia and the serological responses were studied in two breeds of sheep and two breeds of goats, experimentally infected with bluetongue (bt) virus serotype 4. viraemia, detectable by cell culture and embryonated chicken egg inoculation, lasted from the third to sixth day until the 27th-54th day post infection (p.i.). significant differences between sheep and goats were not recorded. lesbos sheep and goats together appeared to have significantly longer viraemias (n = 9, mean 4 ... | 1999 | 10063533 |
| iridescent virus infection in culicoides variipennis sonorensis and interactions with the mermithid parasite heleidomermis magnapapula. | | 1999 | 10066406 |
| a study on bluetongue virus infection in saudi arabia using sentinel ruminants. | four sentinel herds comprising cattle, sheep and goats were established at various localities in saudi arabia. maternal bluetongue antibodies were detected in all four sentinel herds but disappeared in 4-6 months, immediately followed by seroconversion in all. serological results indicated that the animals were recently exposed to bt virus serotypes 10, 12, 15 and 20. the epidemiology of the disease in saudi arabia is discussed. | 1998 | 10192836 |
| congenital baylisascaris sp. larval migrans in a newborn lamb. | a 3-day-old domestic lamb, moribund since birth, was submitted as part of a diagnostic effort concerning weak newborn lambs due possibly to congenital bluetongue virus infection. gross lesions were consistent with such an event. histologic examination of cerebrum and cerebellum revealed multiple granulomas, the age of which required prenatal development. these contained larvae compatible with those of baylisascaris sp. this finding together with evidence that parents of children with neural larv ... | 1999 | 10207377 |
| cross-reactive epitope mimics in a fragmented-genome phage display library derived from the rickettsia, cowdria ruminantium. | epitopes can be mapped by comparing immunoaffinity-selected peptides from fragmented-gene display libraries with the target gene. with larger libraries derived from unsequenced genomes, this is not possible. spurious epitope mimics may be created by expressing dna in a variety of meaningless reading frames and orientations. | 1999 | 10231087 |
| antigenic profile of african horse sickness virus serotype 4 vp5 and identification of a neutralizing epitope shared with bluetongue virus and epizootic hemorrhagic disease virus. | african horse sickness virus (ahsv) causes a fatal disease in horses. the virus capsid is composed of a double protein layer, the outermost of which is formed by two proteins: vp2 and vp5. vp2 is known to determine the serotype of the virus and to contain the neutralizing epitopes. the biological function of vp5, the other component of the capsid, is unknown. in this report, ahsv vp5, expressed in insect cells alone or together with vp2, was able to induce ahsv-specific neutralizing antibodies. ... | 1999 | 10329555 |
| characterisation of monoclonal antibodies to epizootic hemorrhagic disease virus of deer (ehdv) and bluetongue virus by immunisation of mice with ehdv recombinant vp7 antigen. | immunisation of mice with recombinant vp7 antigen of epizootic hemorrhagic disease virus of deer (ehdv) induced serum antibody responses to ehdv. however, from the 19 monoclonal antibodies (mab) produced from these mice, 15 were specific for ehdv and four for bluetongue virus (btv). no mabs were identified with the specificity for an epitope of vp7 shared by both ehdv and btv in spite of the fact that they share a large portion of homology in vp7 amino acids composition. these mabs were divided ... | 1999 | 10333467 |
| serological survey of viral antibodies in llamas (lama glama) in argentina. | this study analysed sera from 390 llamas (lama glama) from nine farms located in three different argentine provinces: buenos aires, cordoba and jujuy. the samples were tested for antibodies against 8 virus known to infect cattle: bovine herpesvirus type 1 (bhv-1), bovine viral diarrhea virus (bvdv), bovine adenovirus (badv iii), bovine enterovirus (bev), bovine rotavirus (brv), bluetongue virus (btv), bovine leukaemia virus (blv), and foot-and-mouth virus (fmdv) by conventional methods such as s ... | 1999 | 10337237 |
| the highly ordered double-stranded rna genome of bluetongue virus revealed by crystallography. | the concentration of double-stranded rna within the bluetongue virus core renders the genome segments liquid crystalline. powder diffraction rings confirm this local ordering with a 30 a separation between strands. determination of the structure of the bluetongue virus core serotype 10 and comparison with that of serotype 1 reveals most of the genomic double-stranded rna, packaged as well-ordered layers surrounding putative transcription complexes at the apices of the particle. the outer layer o ... | 1999 | 10338212 |
| isolation of bluetongue virus serotype 2 from native sheep in india. | | 1999 | 10343380 |
| detection of bluetongue virus genome segment 6 sequences by rt-pcr. | reverse transcription-pcr (rt-pcr) technique was adopted to amplify a 101 basepair nucleotide sequence of bluetongue virus (btv) genome segment 6. the specificity of the amplicon was determined by its approximate size in 3% agarose gel electrophoresis, digestion with restriction enzyme mspi, dot-blot hybridization and cycle sequencing. the technique was found to be suitable for detection of bluetongue virus in infected cell culture and clinical samples. | 1998 | 10356966 |
| the structure of a cypovirus and the functional organization of dsrna viruses. | cytoplasmic polyhedrosis virus (cpv) is unique among the double-stranded rna viruses of the family reoviridae in having a single capsid layer. analysis by cryo-electron microscopy allows comparison of the single shelled cpv and orthoreovirus with the high resolution crystal structure of the inner shell of the bluetongue virus (btv) core. this suggests that the novel arrangement identified in btv, of 120 protein subunits in a so-called 't=2' organization, is a characteristic of the reoviridae and ... | 1999 | 10360362 |
| the barriers to bluetongue virus infection, dissemination and transmission in the vector, culicoides variipennis (diptera: ceratopogonidae). | transmission of bluetongue virus (btv) by a vector species of culicoides was studied using immunohistochemistry, virus titration and in vitro transmission tests. adult female c. variipennis were used from two colonies that are either "transmission competent" or "transmission refractory" after oral infection with btv. intrathoracic (i.t.) injection of btv into the haemocoel always resulted in a fully disseminated infection and transmission of virus in saliva. however, after ingestion of an infect ... | 1999 | 10365165 |