| comparison of three animal viruses with circular single-stranded dna genomes. | no common antigenic determinants and no dna sequence homologies were detected when three animal viruses, chicken anaemia agent (caa), porcine circovirus (pcv), and psittacine beak and feather disease virus (pbfdv), all of which possess circular single-stranded dna genomes, were compared. negative contrast electron microscopy showed that pcv and pbfdv particles were 30% smaller than caa particles and lacked the surface structure of caa. | 1991 | 2006901 |
| purification and biochemical characterization of chicken anaemia agent. | chicken anaemia agent (caa) was purified using differential centrifugation and successive cycles of equilibrium density gradient centrifugation using sucrose and cscl. the purification method was dependent on the use of an antigen-detecting elisa based on a caa-specific monoclonal antibody. virus particles banded at a density of 1.33 to 1.34 g/ml in cscl and measured 23.5 +/- 0.8 nm in diameter. purified preparations contained one major polypeptide (mr 50,000) and a single-stranded, circular dna ... | 1990 | 2109040 |
| porcine circovirus antigens in pk-15 cell line (atcc ccl-33) and evidence of antibodies to circovirus in canadian pigs. | permanent infection of a pk-15 (atcc ccl-33) cell line by the porcine circovirus was demonstrated. this virus appears to be common in the canadian swine population as indicated by the presence of antibodies detected by indirect immunofluorescence or immunoperoxidase tests in the serum of culled sows and sows in commercial herds. one source of the pk-15 cell line was found to be free of circovirus antigen. | 1989 | 2686830 |
| viral dna from cells infected with porcine circovirus. | it has been demonstrated earlier that the genome of the porcine circovirus (pcv) isolated from virions is a circular single-stranded dna (ssdna). this report describes the isolation and characterization of pcv-specific dna from infected cell cultures. two types of double-stranded dna (dsdna) were observed which behaved like supercoiled and relaxed circular molecules, respectively. both types of dsdna displayed infectivity in transfection experiments and are regarded as replicative forms (rf) of ... | 1988 | 2851903 |
| mammalian dna polymerase alpha: a replication-competent holoenzyme form from calf thymus. | calf thymus dna polymerase alpha, like the replication-specific dna polymerase iii holoenzyme of escherichia coli, can be isolated as a distinct complex. a specific multiprotein form of the polymerase alpha, a form designated replication-competent (rc) holoenzyme, consists of a complex of a polymerase-primase core and at least six other polypeptides. the rc holoenzyme can efficiently replicate several naturally occurring templates, including the genomic dna of the porcine circovirus (pcv). the d ... | 1987 | 2894679 |
| calf thymus dna polymerase delta: purification, biochemical and functional properties of the enzyme after its separation from dna polymerase alpha, a dna dependent atpase and proliferating cell nuclear antigen. | we have established a novel procedure to purify calf thymus dna polymerase delta from cytoplasmic extracts. the enzyme has typical properties of dna polymerase delta including a 3' - greater than 5' exonuclease activity and efficiently replicates natural occurring genomes such as primed single-stranded m13 dna and single-stranded porcine circovirus dna, this last one thanks to an associated or contaminating primase activity. a processivity of at least a thousand bases was evident and this in the ... | 1988 | 2899882 |
| replication of single-stranded porcine circovirus dna by dna polymerases alpha and delta. | porcine circovirus is the only mammalian dna virus so far known to contain a single-stranded circular genome (tischer et al. (1982) nature 295, 64-66). replication of its small viral dna (1.76 kb) appears to be dependent on cellular enzymes expressed during s-phase of the cell cycle (tischer et al. (1987) arch. virol. 96, 39-57). in this paper we have exploited the porcine circovirus genome to probe for in vitro initiation and elongation of dna replication by different preparations of calf thymu ... | 1988 | 3207761 |
| replication of porcine circovirus: induction by glucosamine and cell cycle dependence. | multiplication of porcine circovirus (pcv) was found to be inducible by treatment of infected cell cultures with 300 mm glucosamine. one day after glucosamine treatment and after growth in fresh medium, an increase in the number of cells containing virus antigen of up to 50 times as compared to mock-treated cultures was observed. analysis of this phenomenon revealed that replication of pcv dna was induced. only aminohexoses but not hexoses and acetylated aminohexoses were efficacious. the course ... | 1987 | 3619654 |
| studies on epidemiology and pathogenicity of porcine circovirus. | antibodies to porcine circovirus (pcv) which is the smallest animal virus known so far were found in 77-95 per cent of sera from slaughter pigs gathered in berlin and two districts of northern germany. about 60 per cent of these positive sera had relatively high titres similar to those in experimentally infected pigs 3-6 weeks after infection. this indicates that the animals might have become infected during the fattening period. sera from 2-3 year old pigs from a laboratory animal breeding inst ... | 1986 | 3778212 |
| occurrence and role of an early antigen and evidence for transforming ability of porcine circovirus. | by means of indirect immunofluorescence assay (ifa) using natural swine immune serum and hyperimmune serum from rabbits infected with porcine circovirus (pcv), a pcv antigen was detected present prior to the onset of viral and cellular dna synthesis in nucleoli of cells of synchronized and growth stimulated infected ps cell cultures grown for more than 12 h in the presence of hydroxyurea. the number of cells containing specifically fluorescing nucleoli increased with increasing time of growth in ... | 1995 | 7503680 |
| presence of antibodies reacting with porcine circovirus in sera of humans, mice, and cattle. | antibodies reacting with porcine circovirus (pcv) were found in sera of humans, mice, and cattle by means of an indirect immunofluorescence assay (ifa) and an elisa. in man, the highest seroprevalence (23.9% in ifa and 30.2% in elisa) was found among hospitalized patients with fever of partially unclear etiology. non-hospitalized "healthy" persons of the former german democratic republic showed a significantly higher number of positive sera (ifa = 20%) than blood donors from berlin-west (ifa = 8 ... | 1995 | 7544971 |
| poly(a) addition site mapping and polyadenylation signal analysis in a plant circovirus replication-related gene. | the transcripts of a genomic component of coconut foliar decay virus (cfdv), a plant circovirus with a single-stranded dna genome, were characterized by sequencing the 3' termini of the respective cdna clones. it was shown that transcription of the putative replication-related gene terminated at one major site (six bases downstream of the termination codon) in electroporated barley mesophyll protoplasts and that the resulting transcripts were polyadenylated. a deletion downstream of the aataaa s ... | 1995 | 7645233 |
| pathogenesis of porcine circovirus; experimental infections of colostrum deprived piglets and examination of pig foetal material. | the results of virus and antigen distribution following experimental infection of colostrum deprived pigs with pig circovirus (pcv) by oral/nasal and intravenous routes are reported. pcv and antigen were detected using virus isolation and indirect immunofluorescence on cryostat sections respectively. pcv antigen was detected in tissues throughout the body but primarily in spleen thymus, and lung. no pcv antigen or virus was detected in tissue samples from the central nervous system. examination ... | 1995 | 7667906 |
| circovirus infection in european racing pigeons. | | 1995 | 7762128 |
| distribution of antibodies to porcine circovirus in swine populations of different breeding farms. | an enzyme linked immunosorbent assay (elisa) was developed for mass antibody screening to porcine circovirus (pcv) in pig herds of different age groups and of different husbandries. infection with pcv was found to be common in all swine herds tested, with only one exception, a herd at a small farm. statistically, the percentage of pcv negative sera decreased and titer levels increased with increasing age of the pigs. within individual age groups, differences were found to exist between different ... | 1995 | 7794114 |
| particles resembling circovirus in the bursa of fabricius of pigeons. | histological examination of the bursae from 12 pigeons under 4 months old revealed basophilic globular inclusion bodies, 5 to 25 microns in diameter, in the cytoplasm and the nuclei of the various bursal follicular cells. electron microscopy of these inclusions revealed large electron-dense areas containing non-enveloped icosahedral viral particles, 14-19 nm in diameter, either loosely arranged or in paracrystalline array. similar basophilic globular inclusion bodies were seen in the spleen and ... | 1994 | 7832721 |
| computer search of transcription control sequences in small plant virus dna reveals a sequence highly homologous to the enhancer element of histone promoters. | the positions of nucleotide sequences which can act as binding sites for plant transcriptional trans-acting protein factors have been mapped in dna of plant circovirus--coconut foliar decay virus (cfdv). it was found that cfdv promoter region contains sequence motif homologous to the regulatory type i element of plant histone genes. we have also found the presence of the element i motifs in dnas of other small plant viruses. taking into account the mechanism of regulation of histone gene express ... | 1994 | 7841461 |
| production, preliminary characterisation and applications of monoclonal antibodies to porcine circovirus. | the preparation of monoclonal antibodies (mabs) to porcine circovirus is described. preliminary characterisation was carried out on nine mabs obtained from two fusions and included isotyping, virus neutralisation assays and indirect immunofluorescence staining patterns obtained following immunostaining of both a porcine circovirus (pcv)-persistently infected pig kidney (pk/15/w) and vero (vero-pcv) cell line. significant differences in the staining patterns were observed in both cell lines which ... | 1994 | 7856071 |
| evidence of circovirus infection in british pigs. | | 1994 | 7941278 |
| some biological and physico-chemical properties of porcine circovirus. | some important biological and physico-chemical characteristics of porcine circovirus are reported. these include a study on the host distribution in nature, levels of colostrum-derived antibodies in piglets from sero-positive sows and the susceptibility of a range of cell cultures to infection with this virus. the results of haemagglutination studies, resistance to ph 3, chloroform and heat are also reported as are comparative buoyant densities and sedimentation coefficients of porcine circoviru ... | 1994 | 7941842 |
| infection of leucocyte cell cultures derived from different species with pig circovirus. | cultures of leucocyte cells were prepared from pig bone marrow, peripheral blood, lung washings, thymus and lymph nodes. cell cultures were also prepared from peripheral blood from sheep, cattle and a human. immunofluorescent (if) staining of all these cultures, following inoculation with pig circovirus (pcv), detected virus replication in all the cell cultures derived from pigs and in the cell cultures derived from cattle. virus replication in pig leucocyte cell cultures was confirmed by demons ... | 1994 | 7975152 |
| a retrospective study of circovirus infection in pigeons: nine cases (1986-1993). | circovirus infections were diagnosed in 12 pigeons from the united states 4 pigeons from australia, and 1 pigeon from canada (1986-1993). circovirus was identified by electron microscopic examination of basophilic botryoid cytoplasmic inclusions that had a histologic appearance similar to that of psittacine beak and feather disease virus inclusions. inclusions were seen in splenic, bursal, gut-associated, and bronchus-associated lymphoid tissue macrophages and in bursal epithelial cells. inclusi ... | 1994 | 8068746 |
| vaccination and challenge studies with psittacine beak and feather disease virus. | psittacine beak and feather disease virus (pbfdv) was administered to adult galahs (eolophus roseicapillus) by mouth or by intramuscular injection. concentration of pbfdv antibodies in serum and excretion of pbfdv were monitored by haemagglutination inhibition (hi) and haemagglutination (ha) respectively. after oral administration, 17 of 18 galahs remained clinically normal and a small rise in antibody titre was detected in 3 of 18 birds. after intramuscular administration, antibody was detected ... | 1993 | 8117208 |
| circovirus-like infection in a pigeon. | | 1993 | 8286462 |
| circovirus-like particles in the bursae of young racing pigeons. | | 1996 | 8677611 |
| effect of porcine circovirus infection on porcine alveolar macrophage function. | the effect of porcine circovirus (pcv) infection of porcine alveolar macrophage cultures on some of the functional properties of these cells are reported. pcv infection of alveolar macrophages did not effect their ability to phagocytose and kill complement-coated yeast cells or the expression of fc or complement receptors. a transient increase in major histocompatibility complex (mhc) class i expression in pcv-infected cells were observed 4 days after infection and a decrease in the number of ce ... | 1996 | 8677632 |
| circovirus in pigeons. | | 1995 | 8746857 |
| sequence of porcine circovirus dna: affinities with plant circoviruses. | the complete nucleotide sequence (1759 nt) of the ssdna genome of porcine circovirus (pcv) was determined from a cloned dsdna replicative form isolated from pcv-infected cells. sequence analysis detected no significant nucleic acid or protein similarity with another animal circovirus, chicken anaemia virus (cav) but, surprisingly, the highest protein similarity was obtained between the product of the largest predicted pcv orf (orf1; encoding a potential protein of 35.7 kda) and a putative protei ... | 1997 | 9010307 |
| two mrnas are transcribed from banana bunchy top virus dna-1. | we have mapped the mrna transcripts of banana bunchy top virus (bbtv) dna-1. northern hybridization and 3' race analysis identified two poly-adenylated rnas associated with bbtv dna-1. previously, one major orf in the virion sense of dna-1 had been identified, which encoded a putative replication protein (rep). an mrna was identified in bbtv infected bananas that was clearly transcribed from this rep orf. further, a second transcript was identified which mapped to an orf completely within the re ... | 1997 | 9010308 |
| mapping and characterization of the origin of dna replication of porcine circovirus. | the origin of dna replication of porcine circovirus (pcv) was mapped to a 111-bp fragment. on top of a hairpin, a nonanucleotide (tagtattac) homologous to nonanucleotides of other viruses was identified. mutation of this element abolishes replication. pcv may be related to a virus family characterized by single-stranded circular dna genomes, rolling-circle replication, and homology of their rep proteins. | 1997 | 9032401 |
| [circovirus infections in pigeons]. | the first detection of circovirus infection in pigeons in germany is described. the existing experiences with this still little known pigeon disease are summarized and similarities to circovirus infections in other species are shown. | 1997 | 9157630 |
| detection and characterization of porcine circovirus associated with postweaning multisystemic wasting syndrome in pigs. | | 1997 | 9187809 |
| isolation of circovirus from lesions of pigs with postweaning multisystemic wasting syndrome. | postweaning multisystemic wasting syndrome (pmws), an apparently new disease, has been recognized in swine herds in western canada. young pigs with this disease have progressive weight loss, tachypnea, dyspnea, and jaundice, accompanied by interstitial pneumonia, lymphadenopathy, hepatitis, and nephritis. we examined more than 400 pigs from more than 70 herds in alberta, saskatchewan, and manitoba with cases of pmws. a small virus was isolated from a range of tissues from 8 of 8 affected pigs ex ... | 1998 | 9442952 |
| piglet wasting disease. | | 1997 | 9466392 |
| identification of a protein essential for replication of porcine circovirus. | the largest open reading frame of porcine circovirus (orf 4) encodes a protein of 312 amino acids. the predicted gene product of orf 4 shows similarities to rep proteins of other plant circoviruses and geminiviruses. three motifs have been identified that are characteristic for proteins involved in rolling circle replication and the consensus sequence for a putative dntp-binding box (gks) has been found. in this paper, experimental evidence is presented which indicates that orf 4 encodes the rep ... | 1998 | 9472624 |
| isolation of porcine circovirus-like viruses from pigs with a wasting disease in the usa and europe. | samples of lung, liver, kidney, pancreas, spleen, and lymph node from pigs with postweaning multisystemic wasting syndrome from california (usa) and samples of mesenteric lymph nodes from similarly diseased pigs from brittany (france) were examined by light microscopy, in situ hybridization (ish), and/or virus isolation. whole genomic probes for porcine circovirus (pcv) and chicken anemia virus (cav) were used for ish. tissue homogenate supernatants were inoculated onto pk/15 cells for virus iso ... | 1998 | 9526853 |
| nucleotide sequence of porcine circovirus associated with postweaning multisystemic wasting syndrome in pigs. | this article describes the nucleotide sequence of a porcine circovirus (pcv) which possesses a high degree of association with postweaning multisystemic wasting syndrome (pmws), a newly described disease of young pigs. the dna sequence of this pmws-associated pcv (pmws pcv) has 68% homology with that of a previously published nonpathogenic strain of pcv. the strains appear to be closely related yet distinct from one another. | 1998 | 9573301 |
| novel porcine circoviruses from pigs with wasting disease syndromes. | | 1998 | 9602519 |
| porcine circovirus infection in northern ireland. | | 1998 | 9612920 |
| characterization of cis-acting elements affecting strength and phloem specificity of the coconut foliar decay virus promoter. | during replication in its host plant, coconut foliar decay virus (cfdv) remains restricted to the phloem tissue. previous in vivo studies on subgenomic cfdv dna had provided evidence for the phloem specificity of the cfdv promoter. here, new promoter constructs are described which are distinguished by the presence or absence of various cis-acting signals and which gave rise to a 16-fold higher reporter gene (beta-glucuronidase) activity (reaching 30% of the cauliflower mosaic virus 35s promoter) ... | 1998 | 9634093 |
| transcription analysis of porcine circovirus (pcv). | this study focuses on gene expression of porcine circovirus (pcv) in order to identify viral genes and their corresponding mrna transcripts. by northern blot analysis, the existence of three mrnas could be demonstrated. two mrnas are encoded by the viral (-)-strand and one is encoded by the viral (+)-strand. the (+)-strand encoded mrna transcript is 990 nucleotides (nt) long and corresponds to the open reading frame (orf) 1, as shown by s1 mapping. the start point of this transcript is located a ... | 1998 | 9654680 |
| circovirus-like viral associated disease in weaned pigs in indiana. | inclusion bodies with staining affinity and ultrastructural characteristics typical of circoviruses that stained positive for porcine circovirus (pcv)-like virus were demonstrated in association with granulomatous lesions in multiple tissues of three clinically ill 10- to 12-week-old pigs. a syndrome of poor growth and wasting in 5-15% of weaned pigs was an intermittent problem on a 450-sow one-site farrow-to-finish swine farm in indiana. routine diagnostic testing did not demonstrate a cause. g ... | 1998 | 9684976 |
| detection of a novel strain of porcine circovirus in pigs with postweaning multisystemic wasting syndrome. | swine infectious agents, especially viruses, are potential public health risks associated with the use of pig organs for xenotransplantation in humans. therefore, there is a need for better characterization of swine viruses and for the development of diagnostic tests for their detection. we report here isolation of a novel strain of porcine circovirus (pcv) from pigs with postweaning multisystemic wasting syndrome (pmws). affected pigs exhibited severe interstitial pneumonia and lymphoid depleti ... | 1998 | 9705388 |
| characterization of novel circovirus dnas associated with wasting syndromes in pigs. | porcine circovirus (pcv) was initially recognized as a contaminant of continuous pig kidney cell lines and was not thought to be pathogenic. antibodies reactive to the cell culture isolate of pcv (pcv pk-15) are prevalent in the swine population worldwide. recently, pcv pk-15-like antigen and nucleic acid were demonstrated in lesions associated with wasting syndromes in pigs in north america and europe. monoclonal antibodies raised to circoviruses isolated from pigs with wasting syndromes highli ... | 1998 | 9747726 |
| beak and feather disease virus and porcine circovirus genomes: intermediates between the geminiviruses and plant circoviruses. | circoviruses are a diverse group of animal and plant pathogens with undefined relationships to one another but for their non-geminate, non-enveloped capsids and circular, single-stranded dna genomes. the sequences of the beak and feather disease virus and porcine circovirus genomic dnas are presented and analyzed in the context of the other members of the family. sequence comparisons, inferred phylogenies, and geographic occurrence suggest that the ambisense circoviruses, particularly the beak a ... | 1998 | 9787657 |
| psittacine beak and feather disease virus nucleotide sequence analysis and its relationship to porcine circovirus, plant circoviruses, and chicken anaemia virus. | cloning and sequencing of the circular, single-stranded dna of one isolate of psittacine beak and feather disease virus (bfdv) demonstrate a genome composed of a circular molecule of 1993 nucleotide bases. an analysis of the assembled replicative form demonstrated seven open reading frames (orfs) (three in the virion strand and four in the complementary strand), potentially encoding seven viral proteins of >8.7 kda. high amino acid sequence similarity was demonstrated between a potential 33.3-kd ... | 1998 | 9791035 |
| porcine circovirus infection in the republic of ireland. | | 1998 | 9836405 |
| viruses and virus-like particles identified in ostrich gut contents. | samples of either gut content from ostriches showing symptoms of enteritis, or allantoic fluid of eggs inoculated with ostrich isolates, were examined for the presence of viral agents by direct negative-contrast electron microscopy. only a few virus types could be identified with certainty, namely a circovirus (1 sample), a coronavirus (1 sample), a member of either the toga- or bunyaviridae (1 sample), enterovirus (16 samples) and paramyxovirus (26 samples). a large number of samples contained ... | 1998 | 9850509 |
| reproduction of lesions of postweaning multisystemic wasting syndrome in gnotobiotic piglets. | neonatal gnotobiotic piglets were inoculated with tissue homogenates and low- and high-passage cell culture material to determine if the lesions of the newly described porcine postweaning multisystemic wasting syndrome (pmws) could be reproduced. for this, 17 3-day-old gnotobiotic piglets were inoculated intranasally with pelleted chloroform-treated, filtered extracts from cell cultures, filter-sterilized homogenates of lymphoid tissue from pmws-affected piglets, or control materials. piglets we ... | 1999 | 9925205 |
| pathological, immunohistochemical, and in-situ hybridization studies of natural cases of postweaning multisystemic wasting syndrome (pmws) in pigs. | fifteen pigs from five farms on which there had been a previous clinical and histopathological diagnosis of postweaning multisystemic wasting syndrome (pmws) were investigated. at necropsy, enlargement of lymph nodes was the most obvious lesion; other lesions were non-collapsed lungs, ulceration of the gastric pars oesophagica, and cranioventral pulmonary consolidation. microscopical lesions attributable to pmws were found in lymphoid organs (including lymph nodes, tonsil, peyer's patches and sp ... | 1999 | 10098016 |
| identification of a novel gc-rich 113-nucleotide region to complete the circular, single-stranded dna genome of tt virus, the first human circovirus. | the sequence data (h. okamoto et al., hepatol. res. 10:1-16, 1998) of a newly discovered single-stranded dna virus, tt virus (ttv), showed that it did not have the terminal structure typical of a parvovirus. elucidation of the complete genome structure was necessary to understand the nature of ttv. we obtained a 1.0-kb amplified product from serum samples of four ttv carriers by an inverted, nested long pcr targeted for nucleotides (nt) 3025 to 3739 and 1 to 216 of ttv. the sequence of a clone o ... | 1999 | 10196248 |
| evidence for circovirus in cattle with respiratory disease and from aborted bovine fetuses. | | 1999 | 10200889 |
| association of hepatitis viruses with hepatocellular carcinoma in thailand. | hepatocellular carcinoma (hcc) represents the most common form of malignant tumor among males in thailand, an area endemic for hepatitis b virus (hbv) infection. various risk factors have been associated with the development of hcc, among them exposure to certain toxins, and infection with hepatitis viruses, in particular hbv, as well as hcv in areas non-endemic for hbv infection. to examine the association of hepatitis viruses with hcc, our group investigated 101 patients who had been clinicall ... | 1999 | 10213123 |
| isolation and characterisation of circoviruses from pigs with wasting syndromes in spain, denmark and northern ireland. | a porcine circovirus (pcv) was isolated from tissues of pigs with wasting syndromes from spain, denmark and n. ireland. the antigenic profiles of these viruses were determined by indirect immunofluorescence assays using polyclonal antisera and monoclonal antibodies (mabs) prepared against previously isolated pcvs. a rapid and convenient pcr-based test was developed and used for the genotyping of these pcv isolates. these pcv isolates were found to be antigenically and genomically similar to prev ... | 1999 | 10227473 |
| "the clinical scope of porcine reproductive and respiratory syndrome virus infection has expanded since 1987": an alternative perspective. | | 1999 | 10332837 |
| experimental reproduction of severe wasting disease by co-infection of pigs with porcine circovirus and porcine parvovirus. | colostrum-deprived pigs were infected intranasally with a recent isolate of porcine circovirus (pcv2) and a porcine parvovirus (ppv), both from canadian pigs with post-weaning multisystemic wasting syndrome (pmws). four pigs were inoculated with pcv2 alone, three with ppv alone, five with a combined pcv2/ppv inoculum, and two with a chloroform-treated combined pcv2/ppv inoculum. pigs were killed 21-26 days after infection and tissue samples examined for gross and microscopical lesions and for th ... | 1999 | 10373289 |
| evidence that a plant virus switched hosts to infect a vertebrate and then recombined with a vertebrate-infecting virus. | there are several similarities between the small, circular, single-stranded-dna genomes of circoviruses that infect vertebrates and the nanoviruses that infect plants. we analyzed circovirus and nanovirus replication initiator protein (rep) sequences and confirmed that an n-terminal region in circovirus reps is similar to an equivalent region in nanovirus reps. however, we found that the remaining c-terminal region is related to an rna-binding protein (protein 2c), encoded by picorna-like viruse ... | 1999 | 10393941 |
| typing of porcine circovirus in clinical specimens by multiplex pcr. | a multiplex pcr assay was developed to detect and differentiate between the porcine circovirus (pcv) infecting persistently the pk 15 cell line (pcv type i) and the pcv associated with postweaning multisystemic wasting syndrome (pmws) (pcv type ii). dna products with unique sizes characteristic of each type of pcv were obtained. sequencing of these products demonstrated that the nucleotide sequences were type-specific. tissue samples from a total of 42 field cases from québec were studied, among ... | 1999 | 10403678 |
| experimental inoculation of conventional pigs with tissue homogenates from pigs with post-weaning multisystemic wasting syndrome. | this report describes the experimental inoculation of conventional pigs with a tissue homogenate obtained from two pigs affected with postweaning multisystemic wasting syndrome (pmws). eight 2-month-old pigs were inoculated by the intranasal route, and two pigs were left as uninfected controls. clinical signs, rectal temperatures and body weights were recorded. pigs were necropsied at days 14 or 21 post-inoculation, and tissue samples were taken for histopathology and porcine circovirus (pcv) in ... | 1999 | 10405306 |
| post-weaning multisystemic wasting syndrome in spain. | | 1999 | 10460036 |
| identification and incidence of porcine circovirus in routine field cases in québec as determined by pcr. | | 1999 | 10466832 |
| a comparison of in situ hybridization and immunohistochemistry for the detection of a new porcine circovirus in formalin-fixed tissues from pigs with post-weaning multisystemic wasting syndrome (pmws). | post-weaning multisystemic wasting syndrome (pmws) is a recently identified condition affecting pigs in north america and europe. porcine circovirus antigen and nucleic acid have been demonstrated associated with lesions, and a new porcine circovirus designated pcv2 has been recovered from tissues of these animals. in this study, in situ hybridisation and immunohistochemical protocols were developed, optimized and compared for their relative sensitivity in detecting pcv2 antigens and nucleic aci ... | 1999 | 10471021 |
| in-situ hybridization for the detection of porcine circovirus in pigs with postweaning multisystemic wasting syndrome. | in-situ hybridization with a non-radioactive digoxigenin-labelled probe was used to detect porcine circovirus (pcv) in formalin-fixed paraffin wax-embedded tissues from 10 weaned pigs with naturally occurring postweaning multisystemic wasting syndrome (pmws). a 530 base pair dna fragment from an open reading frame 1 was generated by the polymerase chain reaction. by in-situ hybridization, a distinct positive signal was detected in all 10 pigs. the morphology of host cells was preserved despite t ... | 1999 | 10486162 |
| [possible pathogen: porcine circovirus (pcv)]. | | 1999 | 10486869 |
| ultrastructure of porcine circovirus in persistently infected pk-15 cells. | the ultrastructure of porcine circovirus was examined in persistently infected porcine kidney (pk)-15 cells. virus-infected pk-15 cells had large numbers of intracytoplasmic inclusions, and a few cells had intranuclear inclusions. intracytoplasmic inclusions were dispersed throughout the cytoplasm but were most numerous in the perinuclear cytoplasm. inclusion were of various sizes, round to oval, and electron dense and were of two general types. inclusions of the first type were small (0.1-0.5 m ... | 1999 | 10490204 |
| observations on pigeon circovirus infection in ontario. | subclinical pigeon circovirus infection was diagnosed in 1-day-old to 6-week-old birds from a loft with no history of clinical disease. pigeons from other lofts presented with various illnesses and were found at necropsy to be concurrently infected with pigeon circovirus. | 1999 | 10495910 |
| a universal polymerase chain reaction for the detection of psittacine beak and feather disease virus. | a universal pcr assay was designed that consistently detected psittacine beak and feather disease virus (bfdv) in psittacine birds affected with psittacine beak and feather disease (pbfd) from different geographic regions across australia. primers within open reading frame 1 (orf1) of the bfdv genome consistently amplified a 717 bp product from blood and/or feathers of 32 birds with pbfd lesions. the pcr did not amplify a product from the feathers or blood from 7 clinically normal psittacine bir ... | 1999 | 10501171 |
| electron microscopical observations of psittacine beak and feather disease in an umbrella cockatoo (cacatua alba). | psittacine beak and feather disease (pbfd) was diagnosed in an umbrella cockatoo (cacatua alba) with severe feather dystrophy and loss. electron microscopically, the intranuclear and intracytoplasmic inclusion bodies observed by light microscopy were composed of viral particles forming paracrystalline arrays, whorls, semicircles or concentric circles. recovered viral particles from the skin and feather follicle tracts were icosahedral and 15 to 20 nm in diameter. | 1999 | 10535515 |
| detection of porcine circovirus from lesions of a pig with wasting disease in japan. | a wasting disease characterized by progressive weight loss and dyspnea has been observed in weaning pigs on a farm in yamagata prefecture in 1998. histopathologic findings in an affected pig were bronchointerstitial pneumonia and intracytoplasmic clusters of basophilic inclusions in macrophages of lymph nodes, which were similar to those in pigs with postweaning multisystemic wasting syndrome (pmws) recently reported in north america and europe. porcine circovirus (pcv)-like particles were obser ... | 1999 | 10563289 |
| multiplex pcr for detection and typing of porcine circoviruses. | sets of oligonucleotide primers were designed according to the sequences of the open reading frames (orfs) orf1 and orf2 of the prototype nonpathogenic pk-15 strain of porcine circovirus (pcv) type 1 (pcv-1). by the pcr performed with the various primer sets, genomic dna or rna from other bacterial or viral pathogens of the respiratory tracts of pigs could not be amplified. a positive amplification reaction could be visualized with dna extracted from a viral suspension containing as few as 10 vi ... | 1999 | 10565907 |
| persistent infection with chicken anaemia virus and some effects of highly virulent infectious bursal disease virus infection on its persistency. | chicken anaemia virus (cav) infectivity and the effect of highly virulent infectious bursal disease virus (hv ibdv) infection on cav's infectivity were examined in chickens inoculated with cav or inoculated dually with cav and hv ibdv. five chickens inoculated dually with hv ibdv at 35 days old and then with cav at 40 days old exhibited no clinical signs of disease, but showed atrophic bursae of fabricius when necropsied 4 weeks later. upon examining the chickens at 7 days postinoculation (dpi) ... | 1999 | 10607503 |
| reproduction of lesions of postweaning multisystemic wasting syndrome by infection of conventional pigs with porcine circovirus type 2 alone or in combination with porcine parvovirus. | post-weaning multisystemic wasting syndrome (pmws) has recently emerged as an important disease of pigs in north america, europe and asia. porcine circovirus type 2 (pcv2) and porcine parvovirus (ppv) have been isolated from affected pigs. to investigate the pathogenicity of these isolates, groups of colostrum-deprived conventional pigs were inoculated with pcv2 alone (n=4), ppv alone (n=3) or dually with pcv2 and ppv (n=7) and examined post mortem between 21 and 26 days post-infection (dpi). tw ... | 2000 | 10627387 |
| characterisation of pcv-2 isolates from spain, germany and france. | the new isolated circovirus variant pcv-2 is discussed to be the etiological agent of a new emerging swine disease with a variable morbidity and high lethality, postweaning multisystemic wasting syndrome (pmws). pmws has been diagnosed in north america and west europe. clinical signs include dyspnea, loss of weight, lymph node enlargement and lymphocyte depletion in lymphoid tissues. this report describes the characterisation of pcv-2 isolates from animals affected with pmws from germany, spain ... | 2000 | 10653918 |
| identification of porcine circovirus in tissues of pigs with porcine dermatitis and nephropathy syndrome. | thirty-three pigs affected by porcine dermatitis and nephropathy syndrome, 30 from spain and three from the usa, were investigated in order to detect porcine circovirus (pcv) in their tissues. a standard in situ hybridisation technique using a specific dna 317-bp probe based on a well-conserved sequence of pcv (which recognises both pcv-1 and pcv-2) was applied to formalin-fixed, paraffin-embedded tissues. twenty-eight of the 30 spanish pigs and all three american pigs had pcv in at least one ti ... | 2000 | 10678809 |
| pcr detection and characterization of type-2 porcine circovirus. | a polymerase chain reaction (pcr) assay was developed for detecting porcine circovirus (pcv). the assay readily detected type-2 pcv (pcv-2) and type-1 pcv (pcv-1). the pcr primers were designed based on dna sequences conserved in all reported pcv genomes. type 1 pcv and type 2 pcv both produced 438 bp amplification products, which were easily identified and differentiated from one another by restriction fragment length polymorphism (rflp) analysis. porcine circovirus was detected in 55% (931/169 ... | 2000 | 10680656 |
| prevalence of the newly described human circovirus, ttv, in united states blood donors. | a novel nonenveloped single-stranded circular dna virus (ttv) was recently identified. the prevalence of ttv in blood donors in the united states is, however, still unclear. | 2000 | 10686010 |
| porcine circoviruses: a review. | porcine circoviruses (pcv) are small nonenveloped dna viruses containing a unique single-stranded circular genome. previously, no recognized link was found between pcv infection of pigs and disease, and pcv was considered a nonpathogenic agent. over the last 5 years, a "novel" pcv, designated pcv2, has been associated with various disease syndromes in pigs, primarily postweaning multisystemic wasting syndrome (pmws). pigs with pmws have a variety of clinical signs, including debility, dyspnea, p ... | 2000 | 10690769 |
| coinfection by porcine circoviruses and porcine parvovirus in pigs with naturally acquired postweaning multisystemic wasting syndrome. | postweaning multisystemic wasting syndrome (pmws) is an emerging disease in swine. recently, the disease has been reproduced with inocula containing a newly described porcine circovirus (pcv), designated pcv 2, and porcine parvovirus (ppv). in order to determine if these viruses interact in naturally acquired pmws, affected tissues from field cases were examined by immunohistochemistry (ihc) and polymerase chain reaction (pcr) for pcv 2 and ppv, as well as by pcr for the other recognized porcine ... | 2000 | 10690771 |
| pmws and porcine dermatitis nephropathy syndrome in great britain. | | 2000 | 10706335 |
| prevalence of tt virus infection in blood donors with elevated alt in the absence of known hepatitis markers. | recently a novel dna virus (tt virus) has been identified in japan and shown to be associated with elevated aminotransferase levels after blood transfusion. the exact role of ttv in the pathogenesis of liver disease is yet to be established. our aim was to determine the prevalence and role of ttv in the pathogenesis of elevated transaminases in healthy blood donors in the absence of markers for viral hepatitis a-c. | 2000 | 10710073 |
| porcine postweaning multisystemic wasting syndrome in korean pig: detection of porcine circovirus 2 infection by immunohistochemistry and polymerase chain reaction. | this report describes the first diagnosis of porcine circovirus (pcv) infection in weaned pigs with postweaning multisystemic wasting syndrome in korea by immunohistochemistry and polymerase chain reaction. the most unique lesions were multifocal granulomatous inflammation affecting lymph nodes, liver, and spleen, characterized by infiltrates of epithelioid macrophages and multinucleated giant cells. circoviral antigen was detected in formalin-fixed sections and was usually present in large, rou ... | 2000 | 10730945 |
| a sequential study of experimental infection of pigs with porcine circovirus and porcine parvovirus: immunostaining of cryostat sections and virus isolation. | the sequential tissue distribution of virus was investigated using virus isolation and immunofluorescence tests in 1-day-old piglets inoculated with porcine circovirus 2 (pcv2) and/or porcine parvovirus (ppv). enlarged mesenteric lymph nodes were seen in the pig inoculated with pcv2 alone and killed at 26 days post-inoculation (pi). one of the pigs inoculated with pcv2 and ppv and killed at 21 days pi had an enlarged liver. the pig killed at 26 days pi in this group had enlarged liver, kidneys a ... | 2000 | 10763376 |
| high frequency of postnatal transmission of tt virus in infancy. | dna of tt virus (ttv), a novel human circovirus, was tested for in 116 mother-infant pairs who had participated in the adult t-cell leukemia prevention program (app) in nagasaki, japan, and refrained from breast-feeding. by polymerase chain reaction with okamoto's seminested primers, 36 of the 115 (31%) mothers were positive. at the age of 6-8 months, 7 of 29 (24%) and 6 of 72 (8%) infants born to infected and uninfected mothers were positive, respectively (p = 0.047; rr, 2.90). maternal ttv dna ... | 2000 | 10795520 |
| viral wasting syndrome of swine: experimental reproduction of postweaning multisystemic wasting syndrome in gnotobiotic swine by coinfection with porcine circovirus 2 and porcine parvovirus. | one-day-old gnotobiotic piglets were inoculated intranasally with in vitro passaged porcine circovirus 1 (pcv-1), pcv-2, and porcine parvovirus (ppv) alone or in combination (pcv-1/pcv-2, pcv-1/ppv, and pcv-2/ppv). piglets were evaluated for 1) the development of porcine postweaning multisystemic wasting syndrome (pmws), 2) distribution of viral antigens by immunochemistry, and 3) viremia and the presence of viral dna in nasal and ocular secretions and feces. all single agent-infected piglets an ... | 2000 | 10810990 |
| porcine circovirosis in spain. | | 2000 | 10839241 |
| differential recognition of orf2 protein from type 1 and type 2 porcine circoviruses and identification of immunorelevant epitopes. | two types of porcine circovirus (pcv) have been isolated and are referred to as pcv1 and pcv2. pcv1 represents an apathogenic virus, whereas pcv2 is associated with post-weaning multisystemic wasting syndrome. the two pcvs are related, since they display about 70% identity based on nucleotide sequences. in order to discriminate between common and type-specific antigens, an immunocytological approach was used following transfections with cloned circovirus dnas, as well as recombinant proteins exp ... | 2000 | 10859388 |
| development of probes to differentiate porcine circovirus types 1 and 2 in vitro by in situ hybridization. | porcine circovirus type 1 (pcv1), a pk-15 cell line contaminant, and porcine circovirus type 2 (pcv2), associated with post-weaning multisystemic wasting syndrome (pmws), are genetically and antigenically related. several techniques have been developed to detect pcv, including in situ hybridization (ish). previously reported probes used for ish may hybridize with both pcv1 and pcv2 nucleic acids. we attempted to produce probes for ish that can detect and differentiate pcv2 from pcv1 in pcv-infec ... | 2000 | 10865154 |
| pdns, pmws and porcine circovirus type 2 in scotland. porcine dermatitis and nephropathy syndrome. post-weaning multisystemic wasting syndrome. | | 2000 | 10872790 |
| genetic characterization of type 2 porcine circovirus (pcv-2) from pigs with postweaning multisystemic wasting syndrome in different geographic regions of north america and development of a differential pcr-restriction fragment length polymorphism assay to detect and differentiate between infections with pcv-1 and pcv-2. | postweaning multisystemic wasting syndrome (pmws) is an emerging disease in swine. increasing evidence indicates that a variant strain of porcine circovirus (pcv), designated type 2 pcv (pcv-2), is responsible for pmws. to determine the extent of genetic heterogeneity of pcv-2 isolates, the complete genomes of six pcv-2 isolates from different regions of north america were amplified by pcr and sequenced. sequence and phylogenetic analyses confirmed that two distinct genotypes of pcv exist: nonpa ... | 2000 | 10878032 |
| atrophy of the primary lymphoid organs of meat pigeons in italy associated with circoviruslike particles in the bursa of fabricius. | during a survey effected in a meat pigeon slaughterhouse of central italy, atrophy of primary lymphoid organs (bursa of fabricius and thymus) and hypoplasia of bone marrow were observed. histologic, ultrastructural, and hematologic examinations were performed on a total of 80 randomly selected 30-day-old meat pigeons. by histologic studies, lymphocytic depletion and necrosis with cyst formations in the bursa of fabricius were detected in all subjects that showed thymus and bursa atrophy at necro ... | 2000 | 10879928 |
| severe leukopenia and liver necrosis in young african grey parrots (psittacus erithacus erithacus) infected with psittacine circovirus. | this paper describes the signs, clinical pathology, and postmortem findings in 14 young african grey parrots (psittacus erithacus erithacus) that were naturally infected with psittacine beak and feather disease (pbfd) virus (psittacine circovirus). all but two of the parrots had severe leukopenia at clinical presentation. two other parrots also had severe anemia. all birds died within 3 wk after presentation. postmortem examination documented liver necrosis in 11 of 14 birds and secondary bacter ... | 2000 | 10879931 |
| pcv-2-associated pdns in northern ireland in 1990. porcine dermatitis and nephropathy syndrome. | | 2000 | 10887989 |
| characterization of immune response of young pigs to porcine circovirus type 2 infection. | a longitudinal study was conducted to characterize the immune response of young swine to infection with porcine circovirus type 2 (pcv-2). five 8-week-old cesarean-derived, colostrum-deprived pigs were inoculated intranasally and intramuscularly with a field isolate of pcv-2 at a concentration of 10(4) tcid50/ml. along with monitoring for clinical signs and viremia, serum samples were collected from all pigs at day 0 and thereafter every 7 days postinoculation (pi) until the termination of the s ... | 2000 | 10892995 |
| absence of evidence for porcine circovirus type 2 in cattle and humans, and lack of seroconversion or lesions in experimentally infected sheep. | no antibodies to porcine circovirus type 2 were detected in sera from cattle, sheep and humans. experimental infection of lambs with this virus failed to produce lesions or seroconversion. | 2000 | 10893163 |
| evidence of porcine circovirus infection in pigs with wasting disease syndrome from 1985 to 1999 in hokkaido, japan. | an epizootiological survey with histopathological methods was conducted for porcine circovirus in 220 diseased pigs (1-200 days old) in 49 farms from 1985 to 1999. histopathological lesions containing pcv antigen were detected mainly in the lymphoid tissues from 42 of 189 diseased pigs (22.2%) in 4 of 45 farms (8.9%) from 1990 to 1999. the rate of positive pigs gradually increased from 1997 onward and pcv infection was found in 50% of diseased pigs in 1999. histopathologically, the lesions in th ... | 2000 | 10907690 |
| serum antibodies to porcine circovirus type 1 and type 2 in pigs with and without pmws. | | 2000 | 10909911 |
| retrospective serological survey of antibodies to porcine circovirus type 1 and type 2. | a retrospective serological survey was performed to determine the presence of antibodies to porcine circovirus type 1 (pcv1) and porcine circovirus type 2 (pcv2) in serum samples collected from sows at slaughterhouses in canada in 1985, 1989, and 1997. each serum sample was tested by indirect immunofluorescence on pcv-free pk15 cells, on pcv1-infected pk15 cells and on pcv2-infected pk15 cells. for the 3 years studied, sera positive to pcv1 and pcv2 were identified and the number of sera positiv ... | 2000 | 10935885 |
| open reading frame 2 of porcine circovirus type 2 encodes a major capsid protein. | porcine circovirus 2 (pcv2), a single-stranded dna virus associated with post-weaning multisystemic wasting syndrome of swine, has two potential open reading frames, orf1 and orf2, greater than 600 nucleotides in length. orf1 is predicted to encode a replication-associated protein (rep) essential for replication of viral dna, while orf2 contains a conserved basic amino acid sequence at the n terminus resembling that of the major structural protein of chicken anaemia virus. thus far, the structur ... | 2000 | 10950986 |
| isolation and characterization of porcine circovirus type 2 from pigs showing signs of post-weaning multisystemic wasting syndrome in the netherlands. | pigs with wasting syndrome were examined for macroscopic and histopathological lesions, and for porcine circovirus (pcv). histopathological lesions were comparable to those previously documented for post-weaning multisystemic wasting syndrome (pmws). in addition, in seven out of ten examined pmws-affected pigs focal-to-slight mononuclear meningitis and focal cerebral mononuclear infiltrates (4 out of 10) were observed. a virus was isolated from organs and sera from pigs showing wasting syndrome. ... | 2000 | 10952449 |
| quantitative, competitive pcr analysis of porcine circovirus dna in serum from pigs with postweaning multisystemic wasting syndrome. | a competitive pcr (cpcr) assay was developed for monitoring porcine circovirus (pcv) dna in serum samples from piglets. the cpcr was based on competitive coamplification of a 502- or 506-bp region of the pcv type 1 (pcv1) or pcv2 orf2, respectively, with a known concentration of competitor dna, which produced a 761- or 765-bp fragment, respectively. the cpcr was validated by quantification of a known amount of pcv wild-type plasmids. we also used this technique to determine pcv genome copy numbe ... | 2000 | 10970408 |