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the rna helicase ci from plum pox potyvirus has two regions involved in binding to rna.the plum pox virus (ppv) protein ci is an rna helicase, whose function in the virus replication is still unknown. recently, an rna binding domain was mapped to a region of the ci protein that includes the arginine-rich motif vi typical of rna helicases of the superfamily sf2. in the present study, a second region involved in rna binding activity of the ci protein has been identified. northwestern assays with a series of maltose-binding protein fusions that contain different ci fragments showed t ...19968690088
comparison of the safety and immunogenicity of a pneumococcal conjugate with a licensed polysaccharide vaccine in human immunodeficiency virus and non-human immunodeficiency virus-infected children.to compare the safety and immunogenicity of a 5-valent pneumococcal conjugate vaccine to a licensed 23-valent polysaccharide pneumococcal vaccine in hiv-infected and non-hiv-infected children > or = 2 years old.19968852905
first findings of plum pox virus in walnut trees (juglans regia l.)plum pox virus (ppv) was transmitted from infected buds and leaves of walnut tree (juglans regia l.) on the following herbaceous indicators: chenopodium foetidum schrad., nicotiana bigelovii var. quadrivalvis fuchs., n. clevelandii x n. glutinosa. a positive elisa reaction with antisera against ppv was obtained from infected buds and leaves of juglans regia l. and from attacked leaves of indicator plants.19968886101
acute outbreak of porcine parvovirus infection in mozambique.investigations were made to determine the causal agent of an acute outbreak of abortions recorded in a swine herd in mozambique. isolation of porcine parvovirus and demonstration of its specific antibodies accomplished by using enzyme-linked immunosorbent assay, haemagglutination inhibition and immunofluorescent tests, indicated that porcine parvovirus was the causal agent of the abortions. other pathogenic agents causing reproductive failure, e.g. pseudorabies virus, leptospira or brucella spec ...19958966762
processing of the plum pox virus polyprotein at the p3-6k1 junction is not required for virus viability.proteolytic processing of the potyvirus polyprotein is mainly performed by the virus-encoded nia protease, whose cleavage sites are characterized by conserved heptapeptide sequences. partial processing at the cleavage site present between the p3 and 6k1 cistrons by the plum pox potyvirus (ppv) nia protease has been previously shown to occur in vitro. we have now studied the role of polyprotein processing at the p3-6k1 junction in vivo, using a full-length ppv cdna clone. ppv mutant transcripts c ...19959049341
localization of fruit tree viruses by immuno-tissue printing in infected shoots of malus sp. and prunus sp.immuno-tissue printing protocols for the localization of apple chlorotic leaf spot virus (aclsv), stem grooving virus (sgv) and plum pox virus (ppv) in shoots of prunus and malus in vitro have been established for routine diagnosis in a virus elimination program. since these viruses belong to different virus genera, the protocols were adapted according to the properties of the virus under investigation. accumulation of aclsv was highest in the base of the stem and decreased towards the apex of t ...19958537455
detection of respiratory syncytial virus by reverse transcription-pcr and hybridization with a dna enzyme immunoassay.nasal aspirates from 238 infants hospitalized with acute respiratory infections during the winter of 1994 and 1995 were tested for respiratory syncytial virus (rsv) by immunofluorescence assay (ifa) and the viral isolation technique (vit) and by two pcr and hybridization methods: reverse transcription pcr 1 (rt-pcr1), which amplifies the rnas of all rsv strains, and rt-pcr-2, which allows subgroup classification of rsv. rt-pcr-1 and rt-pcr-2 detected viral sequences in 56.7% (135 of 238) and 48. ...19958586738
diagnosis of fetal infection with porcine parvovirus by in situ hybridization.in situ hybridization (ish) for the diagnosis of fetal infection with porcine parvovirus (ppv) was compared with immune electron microscopy (iem) and serology by immunofluorescence (if) for its sensitivity and its applicability in a routine diagnostic laboratory. the technique was applied to the examination of sections of formalin-fixed paraffin-embedded tissues from 68 fetuses. fifty-three of these fetuses were diagnosed serologically since they had a crown rump length of more than 17 cm, i.e. ...19958748552
age-specific prevalence of porcine parvovirus antibody in feral pigs from a site in the northern territory. 19958787527
properties of the active plum pox potyvirus rna polymerase complex in defined glycerol gradient fractions.as a first step in the study of the replication of plum pox virus (ppv) rna, an in vitro virus-specific rna polymerase activity was characterized in a crude membrane extract (martin and garcia, 1991). in this study, we report the fractionation of the crude membrane extract by centrifugation in glycerol gradients. the sedimentation properties after different treatments of the crude extract and its insensitivity to micrococcal nuclease treatment suggest that the rna polymerase activity was localiz ...19957483826
virucidal short wavelength ultraviolet light treatment of plasma and factor viii concentrate: protection of proteins by antioxidants.the use of solvent/detergent mixtures and various forms of heat treatment to inactivate viruses has become widespread in the preparation of blood derivatives. because viruses that lack lipid envelopes and/or are heat resistant, eg, hepatitis a virus (hav) or parvovirus b19 may be present, the use of two methods of virus elimination that operate by different mechanisms has been advocated. we now report on short wavelength ultraviolet light (uvc) irradiation for virus inactivation and enhancement ...19957492794
interferon induction in peripheral blood mononuclear leukocytes of man and farm animals by poxvirus vector candidates and some poxvirus constructs.prototypes of three poxvirus genera--orthopoxvirus (opv), parapoxvirus (ppv), avipoxvirus (apv)--and newcastle disease virus (ndv) as a control, as well as three recombinant opv strains and one recombinant apv strain, were incubated in vitro with peripheral blood mononuclear leukocytes (pbml) of man, sheep and swine. antiviral activity was determined in pbml culture supernatants at different time intervals after virus cell interaction using a cytopathic effect inhibition bioassay. additionally, ...19957502485
rna helicase activity of the plum pox potyvirus ci protein expressed in escherichia coli. mapping of an rna binding domain.the plum pox potyvirus (ppv) cylindrical inclusion (ci) protein fused to the maltose binding protein (mbp) has been synthesized in escherichia coli and purified by affinity chromatography in amylose resin. in the absence of any other viral factors, the fusion product had ntpase, rna binding and rna helicase activities. these in vitro activities were not affected by removal of the last 103 amino acids of the ci protein. however, other deletions in the c-terminal part of the protein, although leav ...19957538661
transmission by aphids of a naturally non-transmissible plum pox virus isolate with the aid of potato virus y helper component.two spanish plum pox virus (ppv) isolates, 5.15 and 3.3, were used in transmission experiments involving the aphid vector myzus persicae, with woody and herbaceous host plants. these isolates differ in the size of their coat protein (cp) and sequence analysis revealed that isolate 3.3 has a 15 amino acid deletion near the n terminus of the cp, affecting the same positions as in a previously reported non-aphid-transmissible ppv isolate from germany. aphid transmission experiments showed that isol ...19957561767
immunogenicity of poliovirus b and t cell epitopes presented by hybrid porcine parvovirus particles.we have analysed the potential capacity of hybrid porcine parvovirus (ppv) capsids to present foreign epitopes to the immune system. foreign sequences were introduced into the n and c termini of ppv vp2, which was previously shown to assemble spontaneously into parvovirus-like particles. the integrity of the c terminus was shown to be essential for preserving the structure of the capsid and therefore could not be used for epitope fusion. in contrast, insertion of sequences corresponding to t and ...19957561778
expression of the plum pox coat protein gene in transgenic nicotiana tabacum plants.plant expression vector pbi 121 containing the gene encoding coat protein of plum pox virus of the skierniewice isolate (cp ppv-s) was prepared (clone pcm1). the construct was used for transformation of nicotiana tabacum plants using an agrobacterium tumefaciens based system. about 82% of kanamycin resistant plant lines contained a transgene (the sequence of cp ppv-s) but only 81% of them actively expressed the ppv-s coat protein gene as measured by rt-pcr.19957653168
adventitious pestivirus rna in live virus vaccines against bovine and swine diseases.live virus vaccines against bovine and porcine diseases were examined for the presence of adventitious pestivirus rna or pestiviruses by reverse transcription-polymerase chain reaction (pcr). pestivirus rna was detected in the live virus vaccines against akabane disease, ibaraki disease, infectious bovine rhinotracheitis, porcine parvovirus infection, transmissible gastroenteritis and japanese encephalitis. pestivirus rna or pestivirus in the fetal bovine serum used to grow the host cells used t ...19957762264
nucleotide sequence of the coat protein gene of the skierniewice isolate of plum pox virus (ppv).the coat protein (cp) gene of the skierniewice isolate of plum pox virus (ppv-s) has been amplified using the reverse transcription--polymerase chain reaction (rt-pcr), cloned and sequenced. the nucleotide sequence of the gene and the deduced amino-acid sequence of ppv-s cp were compared with those of other ppv strains. the nucleotide sequence showed very high homology to most of the published sequences. the motif: asp-ala-gly (dag), important for the aphid transmissibility, was present in the a ...19947913278
porcine parvovirus associated with cutaneous lesions in piglets. 19947948207
return to oestrus after first insemination in sow herds (incidence, seasonality, and association with reproductivity and some blood parameters).as no systematic study has been done to get an accurate estimate of the incidence of return to oestrus after first insemination in sows in the netherlands, the objectives of this investigation were: 1) to obtain an estimate of the incidence of return to oestrus after insemination at the herd level; 2) to investigate the association between incidence of return to oestrus after first insemination and reproduction characteristics in order to get an impression of the economic importance of reproduct ...19947985351
a novel non-mineral oil-based adjuvant. ii. efficacy of a synthetic sulfolipopolysaccharide in a squalane-in-water emulsion in pigs.the adjuvanticity of a sulfolipopolysaccharide (slp) incorporated into a squalane-in-water emulsion (slp/s/w) was compared with that of a mineral oil-in-water (o/w) adjuvant currently used in commercial porcine vaccines. groups of pigs were immunized twice with vaccines comprising either inactivated influenza virus (iflu3 containing strains a/swine, mrc-11 and x-79), inactivated pseudorabies virus (iprv), live pseudorabies virus (prv) or inactivated porcine parvovirus (ippv) as antigen and slp/s ...19948085386
sensitive non-radioactive nucleic acid hybridization assay for plum pox virus detection.a new non-radioactive sandwich hybridization assay was designed to simplify the analysis of a large number of plant samples. plant material was homogenized in 0.5% sds and added directly to the hybridization reaction, in which a pair of identifying probes were used. one of the probes was biotinylated capture rna specific for plum pox virus (ppv) strain sk-68; the other rna probe was synthesized from a plasmid bearing the adjacent sequence of this strain and was labelled with digoxigenin (dig). b ...19947709075
a serologic survey of selected viral and bacterial diseases of european wild hogs, great smoky mountains national park, usa.blood samples were collected from 108 wild hogs (sus scrofa) from the great smoky mountains national park (gsmnp), usa, february to july 1990. we found no antibodies for swine brucellosis, pseudorabies, bovine virus diarrhea virus or porcine rotavirus infection. antibody titers to porcine parvovirus were found in 15 (14%) samples and antibody to one or more leptospiral serovars was found in 48 (44%) samples. thirty-nine (89%) of the 44 positive samples reacted to all five leptospiral serovars te ...19948151810
use of polymerase chain reaction to detect porcine parvovirus associated with swine embryos.the role of porcine parvovirus (ppv) in inducing reproductive failure in swine has been extensively documented. however, information is not available as to the risk of ppv transmission by embryo transfer. using the polymerase chain reaction (pcr) technique, ppv-specific dna was detected in association with 4-day-old porcine embryos incubated in vitro in the presence of nadl-8 strain of ppv, despite attempts to rid the embryos of virus by either washing or treatment with pronase or trypsin. the p ...19948192255
[recent developments in the diagnosis of parapoxviruses].neutralizing and non-neutralizing monoclonal antibodies against parapoxviruses (ppv) were generated by immunizing balb/c-mice with gradient-purified ppv orf d-1701 or purified envelopes. epitope specificity studies identified three distinct epitopes localized in the virus envelope. these antigenic sites allowed a differentiation between orf and stomatitis papulosa viruses. for a rapid diagnosis of parapoxviruses transmission-electron microscopy, immunofluorescence- or immunoperoxidase-staining, ...19947519370
production and characterization of monoclonal antibodies to plum pox virus and their use in differentiation of mediterranean isolates.monoclonal antibodies (mabs) specific to plum pox virus (ppv) were prepared by fusing myeloma cell lines to spleen cells of mice immunized with purified virus, including virus prepared with protease inhibitors to preserve the integrity of the coat protein (cp). the characterized mabs could be used in elisa to differentiate several mediterranean ppv isolates differing in their geographical origin and cp size. at least seven antigenic sites could be established based on the recognition pattern and ...19947526822
rapid immunoassay for the detection of genital herpes infection.we evaluated a new affinity membrane strip test for the diagnosis of herpetic genital infections. test strip results, which are available by immunoassay in 30 min without the need for special equipment, were compared with the results of viral culture.199418475363
genomic organization and mapping of transcription and translation products of the nadl-2 strain of porcine parvovirus.the nadl-2 strain of ppv was cloned into puc19 and independent infectious clones were sequenced. this permitted a correction of published sequences and to predict a cruciform structure as an alternative to the 5'-hairpin of the "-" strand. this 5'-end structural covariance is shared with other parvoviruses of the same group and two alternative sequences ("flip" and "flop") were present in the region of the cruciform. transcript and translation product mapping allowed the prediction of the locati ...19938212598
monoclonal antibodies suitable for plum pox virus determination.monoclonal antibodies (mabs) to plum pox virus (ppv) were obtained after immunization of balb/c mice with purified ppv-w isolate. spleen cells from a mouse showing a high serum titer were used for fusion with sp2/0-ag14 myeloma cells. culture supernatants were screened for specific antibody production against ppv-w isolate using indirect elisa. a total of six stable hybridoma lines producing mabs of igg class were obtained. all four ppv isolates tested (w, a, d and m) can be distinguished by the ...19938314598
a new method for rapidly removing contaminating micro-organisms from porcine parvovirus or pseudorabies virus master-seed suspensions.virus-contaminated cell cultures are a major problem in the bio-industry. methods employed to date to remove contaminating micro-organisms are slow and costly, and a new method is proposed here which is simple and rapid. the method uses polyacrylamide beads coated with specific antibodies which yielded bead-antibody-virus complexes when suspended in the virus solution to be cleared. the purified virus was propagated in cells which show phagocytic activity. vaccine master-seed virus is shown to b ...19938383386
tissue tropisms of porcine parvovirus in swine.late-term gestation swine fetuses, similar to adult animals, are able to effectively mount immune response and survive porcine parvovirus (ppv) infection. an exception to this is the kresse strain of ppv, which causes fetal death in late-term gestation swine fetuses. in an effort to understand the basis for this profound difference in pathogenicity between kresse strain and the prototype strain of ppv, nadl-8, studies were designed to examine potential difference in sites of replication and quan ...19938390826
an economic assessment of porcine parvovirus vaccination.a decision analysis model was designed to evaluate the cost effectiveness of a vaccination program for preventing endemic or epidemic porcine parvovirus (ppv) induced reproductive failure in a 100-sow pig herd. the results showed that the cost of vaccination was less than the cost incurred by continuing endemic ppv infection, or the cost of a severe epidemic. a long term vaccination program is a cost effective method for controlling ppv-induced reproductive failure in pig herds suffering endemic ...19938393655
role of the tk+ phenotype in the stability of pigeonpox virus recombinant.insertion of foreign dna containing the e. coli gpt marker by homologous recombination in the pigeonpox virus (ppv) thymidine kinase (tk) gene and selection for the presence of this dna in the viral genome produced unstable recombinants after 3 plaque purifications. we highlight the persistence of duplicated tk dna sequences arising from single crossing over, due to the growth advantage of tk+ virus. restoration of the tk function by coinsertion of the vaccinia virus tk gene led to stable tk+ re ...19938394070
3'-terminal sequence of the plum pox virus ps and ŏ6 isolates: evidence for rna recombination within the potyvirus group.the sequence of the 3'-terminal 1768 nucleotides of the ps and ŏ6 isolates of plum pox virus (ppv) has been determined and compared with that of the equivalent regions of other ppv isolates sequenced previously. the sequenced region is part of the ppv open reading frame encoding the last 186 amino acids of the nib protein and the coat protein (cp, 330 amino acids), followed by a non-coding region of 220 nucleotides and a poly(a) tail. ppv-ps and ppv(-)ŏ6, just like ppv-el amar, show rather high ...19938445362
evaluation of testing algorithms following the use of combination hiv-1/hiv-2 eia for screening purposes.the licensure of combination human immunodeficiency virus type 1 and type 2 (hiv-1/hiv-2) enzyme immunoassays (eias) by the food and drug administration has been accompanied by a recommendation that u.s. blood banks begin testing the nation's blood supply for hiv-2 by june 1, 1992. the performance of a recently licensed combination hiv-1/hiv-2 eia (genetic systems) was evaluated using 3100 sera collected in the united states. a total of 2,049 sera were obtained from populations with low risk for ...19938457381
[suppression of replication of swine parvoviral antisense rna against the ns ppv gene in swine thyroid gland cells].the possibility of suppression of porcine parvovirus (ppv) reproduction in the culture of thyroid gland cells of a swine that contain the integrated genes for asrna against the nonstructural proteins of the virus has been studied. 10 cell lines with the asrna genes have been obtained. the line with the maximal number of integrated gene copies was used to inflict with the parvovirus. the expression of asrna in this cell line was shown to lead to 95% suppression of ppv replication as compared with ...19938510680
immunodetection of the plum pox virus helper component in infected plants and expression of its gene in transgenic plants.tobacco plants (nicotiana tabacum cv. xanthi) have been transformed via agrobacterium tumefaciens vectors, with cdnas corresponding to the plum pox virus (ppv) cistron 2 encoding helper component (hc-pro) and with the first two and half cistrons of the ppv genome. presence of the hc-pro in ppv-infected plants and transgenic plants transformed with the gene coding for this protein was investigated using specific polyclonal antibodies produced against the ppv hc-pro. the results suggest that two p ...19938517789
comparative sequence analysis of four complete primary structures of plum pox virus strains.the complete nucleotide sequence of plum pox virus (ppv) strain sk 68 was determined from a series of overlapping cdna clones. the exact 5' terminus was determined by direct rna sequencing. the rna sequence was 9786 nucleotides in length, excluding a 3' terminal poly(a) sequence. the large open reading frame starts at nucleotide position 147 and is terminated at position 9568. comparison of cistrons from other plum pox virus strains with those predicted for the sk 68 strain indicated the same ge ...19938122394
[the infectious causes of abortion and stillbirth in swine in switzerland].fetuses and placentae of 171 cases of porcine abortion, stillbirth and mummification were examined for pathological lesions, bacterial infections and ppv (porcine parvovirus) infection. furthermore igg (immunoglobulin g) levels were determined in fetal body fluids. selected maternal sera were tested for antibodies against leptospira, aujeszky's disease and hog cholera. ppv infection was diagnosed in 29.2% of all cases. bacterial abortion was diagnosed in 8.2%. indications for an infectious agent ...19938128797
[return to estrus following first insemination in sow herds (incidence and association with reproductivity and various blood parameters)].as no systematic study has been done to get an accurate estimate of the incidence of return to oestrus after first insemination in sows in the netherlands, the objectives of this investigation were: 1) to obtain an estimate of the incidence of return to oestrus after insemination at the herd level; 2) to investigate the association between incidence of return to oestrus after first insemination and reproduction characteristics to get an impression of the economic importance. these objectives wer ...19937505958
comparison of the virulence of two isolates of porcine parvovirus in 72-day-old porcine fetuses.two strains of porcine parvovirus (ppv), designated kresse and nadl-8, were compared for relative virulence in porcine fetuses. strain kresse was injected into the amniotic fluid of all fetuses of 1 uterine horn of each of 2 pregnant gilts at 72 days of gestation. strain nadl-8 was administered similarly to fetuses of 4 other gilts at the same stage of gestation. all gilts were killed and necropsied 35 days later. selected tissues of all fetuses were tested for infectious virus and viral antigen ...19921325191
immunohistological diagnosis of rabbit haemorrhagic disease (rhd).in the present study the diagnostic use of a biotinylated serum from an immune rabbit was investigated by means of an avidin-biotin-complex (abc)-peroxidase method on paraffin sections. 15 cases of rhd which had been verified histologically and/or by haemagglutination test (ha), 4 suspected cases and 3 cases without history of rhd were included (cases 1 to 22). from 5 prospective cases a wider tissue range was examined (cases 23 to 25 and 29 to 30). furthermore lungs, liver and placenta of 3 fet ...19921325718
field trials of an inactivated virus vaccine against porcine parvovirus.serological response and reproductive performance were estimated in field trials of an inactivated virus vaccine against porcine parvovirus. experiments were carried out in 10 selected pig breeding herds. a total of 277 seronegative gilts were used. two hundred and twenty animals were vaccinated twice before mating, fourteen days apart and revaccinated after farrowing. blood samples were obtained from both vaccinated and non-vaccinated (57 animal) control gilts, one week after the 2nd dose of va ...19921325724
an enzyme-linked immunosorbent assay for detection of porcine parvovirus in fetal tissues.an enzyme-linked immunosorbent assay for porcine parvovirus was developed for laboratory detection of parvovirus antigen in fetal tissues and compared with the fluorescent antibody and haemagglutination tests. the elisa proved to be superior in terms of specificity, sensitivity, speed of performance and ease of interpretation.19921331147
the response of pregnant gilts previously given an inactivated preparation of porcine parvovirus (ppv) to challenge infection with a fully virulent ppv.eight 40-day pregnant gilts, previously treated with an adjuvanted-inactivated viral preparation (aivp) obtained with a field strain of porcine parvovirus (ppv) together with 4 pregnant untreated controls, were subjected to challenge infection with a virulent strain of ppv at the 40th day of gestation. after challenge, all controls became febrile for 2 to 8 days, whereas only one gilt among those which had been treated with the aivp experienced fever which lasted 4 days. virus was consistently r ...19921331715
antigenic variant of swine influenza virus causing proliferative and necrotizing pneumonia in pigs.a new antigenic variant of swine influenza virus was isolated from the lungs of pigs experiencing respiratory problems in 7 different swine herds in quebec. pigs of different ages were affected, and the main clinical signs were fever, dyspnea, and abdominal respiration. coughing was not a constant finding of the syndrome. at necropsy, macroscopic lesions included the overall appearance of pale animals, general lymphadenopathy, hepatic congestion, and consolidation of the lungs. histopathologic f ...19921333815
reproductive failure associated with porcine parvovirus in an enzootically infected pig herd.two outbreaks of porcine parvovirus occurred in a unit of 380 sows, with a subsequent decrease in the size of gilts' litters. of the 203 gilts and 64 primiparous sows which were seronegative at the time of insemination, 134 gilts and 55 primiparous sows seroconverted during pregnancy. of the second parity sows nine of 271 were still seronegative at the time of insemination but all nine seroconverted during their third gestation. the gilts that seroconverted during their first pregnancy produced ...19921338661
antibodies to some swine diseases in commercial piggeries in central zambia.blood samples were taken from 121 sows and gilts on 7 commercial piggeries located around lusaka (zambia). the samples tested negative for antibodies to aujeszky's disease, transmissible gastroenteritis (tge), swine influenza, hog cholera and brucellosis. seventy-eight pigs from 5 farms had positive titres to porcine parvovirus. eighteen sera showed positive titres to leptospira celledoni.19921339985
restriction of porcine parvovirus replication in nonpermissive cells.swine testicle (st) cells and madin-darby canine kidney (mdck) cells differ in their ability to support replication of porcine parvovirus (ppv). viral replication events in st cells, a permissive cell type, and mdck cells, a nonpermissive cell type, were compared in an attempt to elucidate putative mechanisms of restrictive virus replication. radiolabeled ppv bound to the cell surface of both cell types equally well and the binding was shown to be ppv specific, indicating that the restriction wa ...19921370555
construction of a chimeric viral gene expressing plum pox virus coat protein.the capsid-encoding gene of plum pox virus (ppv) was fused with the leader sequence of the coat protein mrna (cp) of tobacco mosaic virus by a novel mutagenesis technique which involves reverse transcription of minus-strand rna [synthesized by in vitro transcription of a double-stranded (ds) cdna clone], using an ad hoc synthetic oligodeoxynucleotide as primer. the resulting cdna was rendered ds and cloned into the plasmid, pbluescribe m13+. transcription of this chimeric construction produced r ...19921398133
the complete nucleotide sequence of pepper mottle virus genomic rna: comparison of the encoded polyprotein with those of other sequenced potyviruses.the complete nucleotide sequence of a pepper mottle virus isolate from california (pepmov c) has been determined from cloned viral cdnas. the pepmov c genomic rna is 9640 nucleotides excluding the poly(a) tail and contains a long open reading frame starting at nucleotide 168 and potentially encoding a polyprotein of 3068 amino acids. comparison of the pepmov c presumptive polyprotein with those of other sequenced members of the potyvirus group, including tobacco etch virus (tev), tobacco vein mo ...19921413501
stillbirths, mummies, abortions, and early embryonic death.stillbirths, mummies, abortions, and early embryonic death have a substantial impact on the profitability of a farm in both endemic and epidemic conditions. fetal death is highly dependent on stage of gestation. implantation occurs around day 14 postmating in sows, and fetal death of an entire litter at this time usually results in a regular return to service. if more than four embryos remain alive, the sow may go on to farrow normally. if fetal death occurs after implantation but before calcifi ...19921446274
production of porcine parvovirus empty capsids with high immunogenic activity.the vp2 gene of porcine parvovirus was cloned in the baculovirus system and expressed in insect cells. the resulting product was present in high yield. it self-assembled into particles which were structurally and antigenically indistinguishable from regular ppv capsids. a high degree of purity of the recombinant capsids was obtained by ammonium sulphate precipitation of cell lysates. these virus-like particles were used as antigen in the immunization of two pigs. the pigs elicited an immune resp ...19921523879
the ns and capsid genes determine the host range of porcine parvovirus.porcine parvovirus is an autonomous parvovirus which normally infects pigs and multiplies in porcine cells in vitro. in this report, we describe the properties of a variant designated p2, which has extended its host range to include canine cells. the variant was able to produce cytopathic effects (cpe) in canine cells, unlike the prototype nadl-2 strain. the variant also produced higher viral antigen and infectivity titers in canine cells than the nadl-2 strain, whereas both strains produced cpe ...19921532105
infectious in vivo transcripts of a plum pox potyvirus full-length cdna clone containing the cauliflower mosaic virus 35s rna promoter.a full-length cdna clone of an aphid non-transmissible isolate of plum pox potyvirus (ppv) was rendered biologically active when placed under the control of the cauliflower mosaic virus 35s rna promoter and the nopaline synthase polyadenylation signal. the cdna was constructed so that the exact 5' end of the ppv rna was present at the transcription initiation site. inoculation of plasmid dna onto nicotiana benthamiana led to systemic infection, whereas local lesions were produced in chenopodium ...19921545225
a monoclonal antibody which recognizes cell surface antigen and inhibits porcine parvovirus replication.monoclonal antibody technologies were applied to the study of early events in porcine parvovirus (ppv) infections in vitro. balb/c mice were immunized with whole swine testicle cells and hybridomas were produced following fusion with myeloma cells. resultant clones were screened firstly in an elisa system, to detect monoclonal antibody recognition of swine testicle cells, and secondly, in a fluorescent antibody test to detect monoclonal antibody which inhibited production of ppv antigen. one clo ...19921562235
proteolytic processing of the plum pox potyvirus polyprotein by the nia protease at a novel cleavage site.the expression of potyvirus genomic rna takes place through translation of its unique long and functional open reading frame into a large polyprotein that undergoes extensive proteolytic processing. most of the cleavages are performed by the virus-encoded nia protease, which cuts the polyprotein at defined sites that are characterized by conserved heptapeptide sequences. we have demonstrated in vitro cleavage activity by the plum pox potyvirus (ppv) nia protease at a novel site, previously ident ...19921585641
nucleotide sequence of the 3'-terminal region of potato virus a rna.the sequence of the 3'-terminal region of the genome of the potato virus a (pva) was obtained from two independent cdna clones. this sequence is 1383 nucleotides long and contains an open reading frame of 1178 nucleotides, ending with the translation termination codon taa and followed by untranslated region of 205 nucleotides. since the n-terminal amino acid of the coat protein of pva was blocked, the position of the putative coat protein cleavage site has been deduced by searching for consensus ...19921604933
a delphi exercise used to identify potential causes of variation in litter size of ontario swine.forty-eight people, considered to the swine experts, were asked to collaborate in a delphi exercise to identify the factors which they believed affect litter size in ontario swine. the panel included 16 animal scientists, 16 pork producers, and 16 veterinarians in swine practice. the ten factors with the highest ratings were parity of the sow, mycotoxins in the feed, infections with porcine parvovirus or leptospira spp., breeding gilts on their second versus first observed estrus, the timing of ...199217423928
a current assessment of the role of porcine parvovirus as a cause of fetal porcine death.one hundred one litters containing 1 or more dead porcine fetuses were collected at an iowa abattoir during a 2-month interval and examined for evidence of viral infection. each of 1,137 fetuses (302 dead, 835 alive) of these litters was tested for porcine parvovirus (ppv) antigens by direct immunofluorescence microscopy (fa) of fetal lung. antigens of ppv were detected in the lungs of most of the fetuses of 11 of the litters. the 11 fa-positive litters contained 105 dead (100 fa-positive) and 1 ...19911645596
experimental in utero infection of pig foetuses with porcine parvovirus (ppv).pig foetuses of various gestational ages were exposed to experimental infection with porcine parvovirus (ppv) in utero. inoculation of 40-, 50- and 60-day-old foetuses with ppv caused foetal death and mummification and spread of the infection to non-inoculated foetuses. inoculation at 80 and 100 days gestation caused pathological lesions of various degrees whereas spread of infection occurred only sporadically. serological examinations of foetuses of different ages suggest that immunocompetence ...19911653481
catalytic antisense rnas produced by incorporating ribozyme cassettes into cdna.a simple strategy is described for the generation of catalytic hammerhead-type ribozymes (rz) that can be used as highly specific endoribonucleases to cleave a particular target rna. the technique requires that a cloned cdna fragment is available which encodes at least a part of the target rna. about 25 different restriction recognition sequences can be utilized to incorporate specifically designed dna cassettes into the cdna. besides some nucleotides which are specific for a certain restriction ...19911660835
outbreaks in quebec pig farms of respiratory and reproductive problems associated with encephalomyocarditis virus.encephalomyocarditis virus (emcv) was isolated from tissues of aborted fetuses and weaned and suckling piglets from 4 different pig farms in quebec. the farms were experiencing reproductive failure in sows of different parities concomitant to respiratory problems in suckling and postweaning piglets. at necropsy, gross lesions were confined to the lung and consisted of pulmonary congestion and edema of various degrees. lesions of multifocal interstitial to proliferative pneumonia were found in th ...19911662074
outbreaks of porcine parvovirus disease in panama.the first recorded isolation of porcine parvovirus (ppv) in panama is described. the outbreaks of ppv disease were characterised by a high prevalence of mummified foetuses, stillborn and weak pigs and a common source of exposure. diagnosis was based on virus isolation and by demonstrating viral antigen in lungs of affected foetuses. six farms in four different provinces were involved. rapid control of the epizootic was achieved through the use of an inactivated ppv vaccine in the affected farms.19911662424
molecular biology of the viral haemorrhagic disease virus of rabbits.viral haemorrhagic disease virus (vhdv) of rabbits is a small, nonenveloped dna virus which contains a linear, single-stranded genome approximately 7,000 bases in length. the virions are icosahedral in symmetry, consisting of 180 subunits with pentamer-hexamer clustering. the capsid is composed of four structural polypeptides: vp1:60-61 kda, vp2:54.7 kda, vp3:52 kda, and vp4:26-28 kda. vp1 is a major structural polypeptide which constitutes approximately 54.7% of the total viral proteins. there ...19911760580
predicting human immunodeficiency virus type 1-positive sera by using two enzyme immunoassay kits in a parallel testing format.two algorithms for screening sera for antibody to human immunodeficiency virus type 1 were compared for their efficiency in identifying a true-positive sample in a population with heterogeneous risk factors, using the criteria of specificity and positive predictive value (ppv). in the first algorithm, all sera were screened by using a single enzyme immunoassay (eia) kit, and a specificity of 98.6% and a ppv of 69.3% was calculated for true-positive sera. the second algorithm employed two differe ...19911774256
nucleotide sequence of the 3'-terminal region of the rna of the el amar strain of plum pox potyvirus.the nucleotide sequence of the 3'-terminal 4773 nucleotides of the rna of a widely divergent, aphid-transmissible strain of plum pox potyvirus isolated from egypt (ppv-el amar) was determined. the sequenced region covers the carboxy terminus of the cylindrical inclusion (ci) gene, and the putative 6k protein, the nia protease, the nib rna polymerase and the coat protein genes, linked together as one large open reading frame (orf) in a fashion similar to the canonical genomic organization of othe ...19911856701
polymerase chain reaction (pcr) amplification for the detection of porcine parvovirus.a polymerase chain reaction (pcr) amplification method was developed and evaluated to detect porcine parvovirus (ppv). a pair of 20-base primers and an oligonucleotide probe were derived from the dna sequences common to two isolates of ppv, nadl-8 and nadl-2. the primers flanked 118-bp nucleotides within the region coding for the major structural protein vp2. after dna amplification of ppv replicative form (rf), a 158-bp fragment was detected in agarose gels. this amplified fragment was shown to ...19911874916
the complete nucleotide sequence of pea seed-borne mosaic virus rna.the complete nucleotide sequence of the rna genome of pea seed-borne mosaic virus (psbmv) was determined from cloned cdna and by direct sequencing of viral rna. the psbmv genomic sequence was determined to be 9924 nucleotides in length excluding the poly(a) tract. the rna contained an open reading frame (orf) of 9618 nucleotides with the potential to encode a polyprotein with a calculated mr of 364000 (364k). the orf was flanked by a 5' untranslated leader sequence of 143 nucleotides and a 3' un ...19911940858
identification of the initiation codon of plum pox potyvirus genomic rna.the expression of plum pox potyvirus (ppv) genomic rna takes place through translation of its unique long and functional open reading frame (orf) into a large polyprotein that undergoes extensive proteolytic processing. in this paper we show that the aug recognized as the initiation codon of the ppv orf by in vitro translation systems is the one found at nucleotide position 147, in spite of the presence at position 36 of an in-phase aug that marks the start of the orf. deletion of a substantial ...19911962436
proteolytic activity of plum pox virus-tobacco etch virus chimeric nia proteases.plasmids encoding chimeric nia-type proteases made of sequences from the potyviruses plum pox virus (ppv) and tobacco etch virus (tev) have been constructed. their proteolytic activity on the large nuclear inclusion protein (nib)-capsid protein (cp) junction of each virus was assayed in escherichia coli cells. the amino half of the protease seemed to be involved neither in the enzymatic catalysis nor in substrate recognition. in spite of the large homology among the ppv and tev nia-type protease ...19912015911
plum pox potyvirus rna replication in a crude membrane fraction from infected nicotiana clevelandii leaves.in vitro synthesis of plum pox potyvirus (ppv)-specific nucleic acid has been measured in a crude fraction prepared from leaves of ppv-infected nicotiana clevelandii plants. using alkali and dnase treatments, the synthesized nucleic acid was shown to be rna. the electrophoretic mobility and the differing sensitivity to rnase at high and low salt concentrations allowed the identification of in vitro products probably corresponding to replicative form and replicative intermediate rna, as well as t ...19912016593
comparison of two rapid methods for detection of respiratory syncytial virus (rsv) (testpack rsv and ortho rsv elisa) with direct immunofluorescence and virus isolation for the diagnosis of pediatric rsv infection.the ability of two commercial immunoassays to detect respiratory syncytial virus (rsv) in respiratory specimens was evaluated as follows: 152 specimens were tested by testpack rsv (abbott), and 72 were tested by ortho rsv elisa (ortho). test outcomes were compared with those of virus isolation alone, direct immunofluorescence assay (dfa) alone, or virus isolation and/or dfa. testpack rsv versus virus isolation showed 91% sensitivity, 96% specificity, 93% positive predictive value (ppv), and 95% ...19912037684
molecular cloning of porcine parvovirus dna for the purpose of obtaining viral antigen synthesis in bacteria.an expression of porcine parvovirus 1.05 kb dna fragment was obtained in escherichia coli under the control both of pr-lambda and lac-promoters. the product of expression under pr-control was demonstrated to show ppv-specific antigenic properties. its electrophoretic mobility corresponded to a molecular weight of approximately 45 kd.19902102651
dot hybridization detection of plum pox virus using 32p-labeled rna probes representing non-structural viral protein genes.a cdna library covering the complete genome of plum pox virus strain d (ppv d) has been obtained, and an endonuclease restriction map derived from it. this map was superposed on the ppv genomic organisation map, established for a nonaphid transmissible strain of ppv (maiss et al., 1989). this allowed us to select seven probes, corresponding to different regions on the ppv genome. these probes were tested in a dot-blot hybridization assay for the detection of ppv. probes of various lengths (0.25 ...19902148174
[the effect of parvovirus vaccination in sows through their 4th parity and the role of influenza h1n1 virus].the effects of vaccination of a porcine parvovirus (ppv) in gilts and the first four litters were studied in a pig-breeding herd. in addition to determination of the technical results, ppv and influenza (h1n1) titres were measured. from the serological findings it was apparent that ppv and influenza (h1n1) virus circulated during the trial. the number of total-born and live-born piglets was significantly higher in the first litter when ppv-vaccinated and non-vaccinated gilts were compared. on th ...19902156355
development of a vaccine preventing parvovirus-induced reproductive failure in pigs.an inactivated porcine parvovirus (ppv) vaccine for the prevention of ppv-induced reproductive failure in pigs was developed, using virus grown in cell culture, inactivated with beta-propiolactone and adjuvanted with aluminum hydroxide. the vaccine was tested for safety by subcutaneous injection into pregnant gilts. there were no signs of abnormal reactions nor evidence of ppv infection in the gilts or their foetuses when they were sacrificed 6 weeks after vaccination. to demonstrate that the va ...19902165775
persistence of porcine parvovirus in swine infected in utero and followed through maturity.the potential of porcine parvovirus (ppv) to persistently infect swine exposed in utero was studied. forty eight 80- to 95-day-old fetuses from 5 ppv seropositive sows were inoculated intramusculary with a virulent strain of ppv or with cell culture medium (controls). blood samples were collected at birth prior to nursing and at monthly intervals thereafter and tested for antibodies to ppv. virus-inoculated and control pigs were euthanized at either 1 week before birth (-1), at birth (0) and at ...19902166412
establishment of transformed swine fibroblast cell lines using sv40 large t antigen.swine testicle cell lines were established by transformation of primary swine testicle (pst) cells with an sv40 plasmid (psv3-neo), which contains genes conferring resistance to neomycin and expressing sv40 large t antigen. plasmid dna was transfected into pst cells using a lipofection system. two related plasmids, psv2-neo and psv5-neo, failed to induce transformed cells. cells transformed with psv3-neo formed single colonies that were resistant to the antibiotic, g418, and expressed large t an ...19902175590
comparison of commercial kits for the detection of antibody to human immunodeficiency virus type 1 (hiv-1) in nigeria.four commercial kits for the detection of antibodies to hiv-1 were compared with regard to their sensitivity, specificity and positive predictive value. the wellcozyme competitive enzyme immunoassay was the least sensitive (62.5%), while roche eia, was the most sensitive (100%). all the commercial kits gave false negative results except the roche eia system. the serodia particle agglutination test had the least positive predictive value of 26.9% while roche eia had the highest (88.9%). our resul ...19902191859
sensitive enzyme immunoassay for the rapid diagnosis of influenza a virus infections in clinical specimens.samples of nasopharyngeal secretion (nps) from 100 infants and small children admitted for acute respiratory disease during the period from january to march 1989 were examined for the presence of influenza a virus. all samples were tested by enzyme immunoassay (eia), fluorescent antibody (fa) technique and by isolation in cell culture 3-6 h after they were obtained from the patients. of 24 influenza strains found by isolation, 21 were detected by eia and 19 were fa+. in comparison with virus iso ...19902203125
the complete nucleotide sequence of an infectious clone of porcine parvovirus, strain nadl-2.the complete nucleotide sequence of an infectious clone of porcine parvovirus, strain nadl-2, was determined. the nucleotide sequence organization of the viral genome was found to be similar to that of the other autonomous parvoviruses, such as canine parvovirus and minute virus of mice.19902219713
replication of two porcine parvovirus isolates at non-permissive temperatures.previous studies have shown that replication in vitro of the porcine parvovirus (ppv) isolate, kbsh, was restricted at 39 degrees c but not at 37 degrees c. in contrast, replication of the kresse isolate was restricted at 37 degrees c but not at 39 degrees c. in this study, kresse and kbsh isolates were passaged up to ten times in swine testicle (st) cells at non-permissive temperatures, and at subsequent passage viral protein synthesis, viral dna synthesis, and progeny virus were evaluated. kbs ...19902222184
rna helicase: a novel activity associated with a protein encoded by a positive strand rna virus.most positive strand rna viruses infecting plants and animals encode proteins containing the so-called nucleotide binding motif (ntbm) (1) in their amino acid sequences (2). as suggested from the high level of sequence similarity of these viral proteins with the recently described superfamilies of helicase-like proteins (3-5), the ntbm-containing cylindrical inclusion (ci) protein from plum pox virus (ppv), which belongs to the potyvirus group of positive strand rna viruses, is shown to be able ...19902263459
mutational analysis of plum pox potyvirus polyprotein processing by the nia protease in escherichia coli.a binary escherichia coli expression system has been used to study the pathway for proteolytic processing of the plum pox potyvirus (ppv) polyprotein. trans cleavage at the carboxyl end of the cylindrical inclusion protein occurred, although with lower efficiency than that at the large nuclear inclusion protein-capsid protein junction. no trans cleavage at the carboxyl end of the small nuclear inclusion protein (nia) was detected. the proteolytic activities at different cleavage sites of several ...19902273380
porcine parvovirus survey. 19902309430
excretion of porcine parvovirus through the genital tract of boars.the putative binding of porcine parvovirus (ppv) to semen components in vitro was examined along with the shedding pattern of ppv in oronasally infected boars. porcine parvovirus dna was determined to be bound to spermatozoa that had been incubated in vitro with ppv and washed to remove loosely adherent virus. to determine whether ppv was shed in the semen, four 8-month-old boars, seronegative for ppv, were inoculated oronasally with a virulent strain of ppv. prior to virus inoculation, a cathet ...19902316910
infectious in vitro transcripts from a plum pox potyvirus cdna clone.a full-length cdna clone of the 9786 nt plum pox virus (ppv) rna genome has been cloned downstream from a phage t7 rna polymerase promoter. the rnas synthesized by in vitro run-off transcription in the presence of the 5' cap analog m7gpppg were infectious in nicotiana clevelandii plants. no infectivity was detected when the transcriptions were carried out in the absence of the cap analog. inoculations of the local lesion host chenopodium foetidum indicated that the infectivity of the synthetic t ...19902371774
construction of an infectious genomic clone of porcine parvovirus: effect of the 5'-end on dna replication.the linear single-stranded dna genome of the porcine parvovirus, an autonomous parvovirus, was cloned in duplex form into the bacterial plasmid puc18 using a simple and reliable method. these clones were stable during propagation in escherichia coli jm109. the recombinant clones of porcine parvovirus were infectious when transfected into monolayers of swine testes cells as identified by the development of cytopathic effect, indirect immunofluorescence with specific antiserum, and hemagglutinatio ...19902371779
multiplication of attenuated and virulent porcine parvoviruses in colostrum-deprived, neonatal pigs.colostrum-deprived, neonatal, 2 days old pigs were inoculated with the attenuated ht-/sk or the virulent 90hs strain of porcine parvovirus (ppv) by the oral or subcutaneous route and sacrificed 2, 4 or 6 days after inoculation. then, comparison was made on viral multiplication in pigs between the two strains. pigs inoculated with the ht-/sk strain showed no detectable viremia or hi antibody responses against ppv within 6 days after inoculation. only in pigs inoculated by the subcutaneous route, ...19901962832
detection of porcine parvovirus using nonradioactive nucleic acid hybridization.nonradioactive slot blot hybridization assays were established for the detection of porcine parvovirus (ppv), using either a digoxigenin-labeled dna probe or a biotinylated rna probe. all probes were prepared from a 3.3-kb pst1-ecor1 dna fragment of the nadl8 isolate of ppv. the sensitivity and specificity of the probes in a slot blot system were evaluated in comparison with a 32p-radiolabeled rna probe. using an anti-digoxigenin alkaline phosphatase detection system, at least 1 ng of viral repl ...19901965580
development of hybridization probes on the basis of recombinant dna to identify porcine parvoviruses and rotaviruses.porcine parvovirus (ppv) and porcine rotavirus (prv) infections can be diagnosed, and the diagnosis greatly contributes to their control. for the diagnosis of ppv and prv of pigs recombinant dna were obtained which could be used as hybridization probes. homology between ppv-rna and cloned cdna was confirmed, and the ability of plasmid probes to detect prv was demonstrated. hybridization with preparations of both ppv-infected cells and purified ppv gave positive reproducible results. the results ...19901966361
in vitro exposure of preimplantation porcine embryos to porcine parvovirus.early porcine embryos at the four- to eight-cell stage can be infected with either the virulent (nadl-8) or avirulent kbsh strain of porcine parvovirus (ppv) by microinjection or by incubation of embryos with virus. treatment of embryos by microinjection of virus or incubation in media with virus did not significantly inhibit in vitro development of the embryos when compared with untreated controls. rna-dna hybridization was used to identify the presence of virus associated with embryos. it was ...199016726750
the interferon sensitivity of selected porcine viruses.the objective of this study was to compare the sensitivity of 11 porcine viruses to the antiviral effects of porcine interferon-alpha in serum from piglets which had been infected 19 h previously with transmissible gastroenteritis virus, and of porcine interferon-beta prepared in pk-15 cells by induction with polyinosinic:polycytidylic acid, in yield reduction assays in pig kidney cells which were treated with interferon before virus challenge, and both before and after virus challenge. the most ...19892492445
evaluation and simplification of the world health organization clinical case definition for paediatric aids.the world health organization (who) clinical case definition for paediatric aids was tested during a 1-month period on 221 consecutive hospitalized children in kigali, rwanda. relevant clinical features not included in the who case definition were also evaluated. thirty-four out of the 221 children (15.4%) were hiv seropositive. although the specificity of the who case definition was high (92%), the sensitivity and the positive predictive value (ppv) were low (41 and 48%, respectively). the foll ...19892500955
an enzyme-linked immunosorbent assay for detection of antibodies to porcine parvovirus.an enzyme-linked immunosorbent assay (elisa) was developed for detection of antibodies to porcine parvovirus (ppv). antisera to ppv were raised in pigs, for which ppv grown on pk15 cells was used for primary intranasal inoculations, and ppv cultured on autologous kidney cells for booster immunisations. a competition elisa was developed, based on the principle of a double antibody sandwich assay, using immunoglobulin fractions prepared from these sera. the elisa was compared with a haemagglutinat ...19892542351
characterization of a parvovirus isolated from the diarrheic feces of a pig.a small dna virus was isolated from the feces of a sow with diarrhea and identified as a parvovirus on the basis of its properties. the virus replicated preferentially in cell cultures of swine origin, including primary porcine thyroid gland and kidney cell cultures in which the cytopathic effect developed. the virus agglutinated erythrocytes of guinea pig, mouse and human group o but not these of chicken. the growth of the virus was inhibited by 5-iodo-2'-deoxyuridine. the virus was resistant t ...19892544760
in vitro assessment of viral antigen content in inactivated aluminum hydroxide adjuvanted vaccines.antigen capture enzyme immunoassays (elisa) were developed to assess the antigenic content of inactivated aluminum hydroxide (ah) adjuvanted porcine parvovirus, pseudorabies, and infectious bovine rhinotracheitis vaccines. reference preparations of these viruses were constructed as a basis for comparison. because ah-associated elisa interference was largely circumvented, the need for isotopic or complex antigen-adjuvant desorption methods was eliminated. a 4-parameter logistic model related opti ...19892550498
a serological survey of swine parvovirus infection in italy.a serological survey to detect the presence of porcine parvovirus (ppv) infection in italy and its geographic distribution was conducted. 1,332 samples of serum collected in 1983/1984/1985 were taken from pig breeding herds and, to a lesser extent, from fattening piggeries of representative regions of italy. they were tested using the hemagglutination inhibition test (hit). the results of the serological study indicate that parvovirus infection is widespread in italian herds having 70.3% of sera ...19892550741
nucleotide sequence analysis of the capsid genes and the right-hand terminal palindrome of porcine parvovirus, strain nadl-2.the genome of the porcine parvovirus, strain nadl-2, has been cloned and the sequence of map units 28 to 100, which is 3670 bp in length and contains the capsid coding regions and the right-hand terminal palindrome, has been determined. the sequence shows extensive homology with other parvoviruses such as mvm, h-1, cpv, and fpv in the capsid coding region. given the information available from these sequences, the regulatory and capsid coding regions for ppv have been proposed and the amino acid ...19892596019
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