serological procedures to determine time of infection of pigs with porcine was found possible to correlate serological responses to porcine parvovirus (ppv) with the time after infection. two procedures were used for ppv antibody measurement: an immunodiffusion technique to measure precipitating antibody and a haemagglutination inhibition (hi) procedure to measure concentration of 2-mercaptoethanol (2-me) sensitive antibody. both procedures successfully related antibody titres to time post-infection, but it was considered that a 2 m 2-me hi procedure showed the grea ...1978687263
prevalence of porcine parvovirus-induced reproductive failure: an abattoir study. 1978659307
elimination of porcine parvovirus from infected cell cultures by inclusion of homologous antiserum in the nutrient medium.cell cultures of porcine fetal kidney and porcine adult thyroid gland were freed of infection with porcine parvovirus by adding homologous viral antiserum to their nutrient medium. the use of antiserum appeared practical and effective for eliminating the virus from contaminated cell lines.1978629467
the effect on reproductive performance of porcine parvovirus infection in a susceptible pig acute episode of reproductive failure occurred following natural introduction of porcine parvovirus to a susceptible herd of 48 breeding sows. serological data gave a close estimate of the time that infection spread through the herd, and enabled a correct forecast of the reproductive failure that followed. severe fetal mummification was seen over a three-week period. epidemiological data is presented strongly linking in utero parvovirus infection with the mummification that occurred, and the ...1977560744
prenatal infection following maternal exposure to porcine parvovirus on either the seventh or fourteenth day of gestation.intranasal and oral exposure of two gilts to porcine parvovirus on either the seventh or 14th day of gestation resulted in prenatal infection. normal appearing fetuses and necrotic remnants of what were believed embryos and extraembryonic membranes were found when the gilts were necropsied seven weeks after exposure. the presence of masses of porcine parvovirus antigen throughout necrotic tissues of six of seven embryos, but not in any of the nine normal appearing fetuses suggested that embryoni ...1979427636
serological responses in pigs vaccinated with inactivated porcine parvovirus.the safety and immunogenicity of inactivated porcine parvovirus (ppv) vaccines were investigated. both beta-propiolactone and formalin successfully inactivated virus without destroying immunogenicity, which was considerably enhanced by incorporation of a gel adjuvant in the vaccine. using the formalised-gel vaccine, initial antibody responses were demonstrated in susceptible piglets and adult pigs at 7 days after vaccination. these antibody responses persist at significant levels for at least 6 ...1977565631
replication of porcine parvovirus in peripheral blood lymphocytes, monocytes, and peritoneal macrophages.porcine peripheral blood lymphocytes (pbl), peripheral blood monocytes, and peritoneal macrophages were examined for their ability to support porcine parvovirus (ppv) replication. the cell cultures were infected with the nadl-2 strain of ppv at 0.1 multiplicity of infection. pbl cultures were stimulated with the following phytomitogens: phytohemagglutinin m, concanavalin a, and pokeweed mitogen. unstimulated pbl cultures infected with ppv and uninfected pbl stimulated with phytomitogens served a ...1979574124
effect of inseminating seropositive gilts with semen containing porcine parvovirus. 1979487052
an outbreak of swine foetal mummification associated with porcine parvovirus. 1977856144
observations on rapid diagnosis of porcine parvovirus in mammified foetuses. 1977856145
effect of porcine parvovirus on development of fertilized pig eggs in vitro. 1979435962
reproductive disease experimentally induced by exposing pregnant gilts to porcine parvovirus.porcine parvovirus (ppv) was administered intravenously or intranasally and orally between the 22nd and the 81st days of gestation to 20 pregnant gilts that were free of hemagglutination-inhibiting (hi) antibody for ppv. gilts were exposed to 1 or both of 2 strains (nadl-7, nadl-2) of ppv and were killed 21 or more days later. fetal and maternal fluids and tissues collected at necropsy were tested for ppv, viral antigen, and hi antibody. transplacental infection occurred with 11 of 12 gilts give ...1976999067
demonstration of parvovirus in canadian swine and antigenic relationships with isolates from other countries.a canadian isolate of porcine parvovirus, isolated from cultured pig thyroid cells, was shown to be antigenically indistinguishable from a british (59e/63) and a german (g10/1) strain when treated by the modified direct complement-fixation, the hemagglutination-inhibition and the fluorescent antibody tests. these tests also revealed that antibodies to parvoviruses were detectable in a large proportion of the conventionally raised pigs in the provinces of quebec and ontario. cell cultures, prepar ...1978356941
letter: rapid diagnostic techniques for detection of porcine parvovirus infection in mummified foetuses. 1976944570
immunoglobulins in blood serum of foetal pigs.a total of 1,147 samples of blood serum, collected from porcine foetuses, were examined for the presence of immunoglobulin. the foetuses, from 182 sows, were sampled at abattoirs in queensland during 1975. for detection and measurement of immunoglobulins, rabbit anti-pig serum and monospecific anti-pig igg, anti-pig igm and anti-pig iga were employed in immunoelectrophoresis, double diffusion and single radial immuno-diffusion assays. twenty-four foetuses (from 7 litters) had detectable igg or i ...1978655968
[verification of the plum pox virus (ppv) using the tray test (author's transl)].a comparison of 6 host plants reacting by local lesion if infected by the plum pox virus (ppv) demonstrated that beside chenopodium foetidum schrad. also nicandra physaloides (l). gärtner, nicardra physaloides violacea bitter and verbena officinalis l. are pretty well suitable to verify the ppv serving as locally reacting test plants. using the tray test, the ppv was verifiable by separated leaves of c. foetidum schrad., n. physaloides violacea bitter, n. physaloides (l.) gärtner and v. officina ...1978664936
antibody to porcine, feline and rat parvoviruses in various animal species.porcine, feline and rat parvoviruses were shown to be antigenically distinct. specific antibody to feline and rat parvoviruses was shown in a high proportion of porcine sera, and to the porcine parvovirus in sera from cattle, sheep, cats, guinea-pigs, mice and rats, but not from horse, dog, rabbit, chicken or human.1976951520
efficacy of an inactivated virus vaccine for prevention of porcine parvovirus-induced reproductive failure.gilts vaccinated im either once (4 gilts) or twice (2 gilts) with an acetylethyleneimine-inactivated porcine parvovirus (ppv) vaccine before they were bred were subsequently exposed intranasally and orally to virulent ppv at about the 40th day of gestation (from 37 to 43 days). at 2 weeks after vaccination, all had hemagglutination-inhibiting (hi) titers for ppv (from 20 to 80) which decreased by the time the immunity was challenged with virulent virus (from 10 to 40), but increased thereafter ( ...1979464358
an enzyme-linked immunosorbent assay for detection of porcine parvovirus in fetal 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
observations on the pathogenesis of porcine parvovirus infection.differences in the pathogenesis of porcine parvovirus (ppv) were shown when pregnant gilts were infected by the oral and intramuscular (i.m.) routes. by the oral route, ppv took 23-32 days to cross the placenta following infection of the dam, as compared to 15 days by the i.m. route, successful transplacental infection occurred following oral infection of dams only in the second third of gestation, whilst i.m. infection resulted in infection of foetuses in both first and second thirds of gestati ...1976986801
experimentally induced infection of neonatal swine with porcine pigs were exposed to porcine parvovirus (ppv) and killed at postinoculation day (pid) 3 or 7. signs of illness and lesions were not seen. hemagglutination-inhibition (hi) antibodies for ppv were present in the serums of pigs killed on pid 7. as detected by viral isolation and immunofluorescence, ppv was mainly located in rapidly proliferating tissues. heaviest concentration of viral antigen was in the germinal centers of lymph nodes and lightest concentration of antigen was in the ce ...19751098530
porcine parvovirus infection in vitro: a study model for the replication of parvoviruses. ii. kinetics of virus and antigen production. 1976986740
virus-like particles in buffy coat cells of normal goats and goats infected with progressive pneumonia electron microscopy, virus-like particles (vlp) were seen in neutrophils and lymphocytes from buffy coats prepared from 5 goats inoculated with progressive pneumonia virus (ppv) and 3 noninoculated goats. the vlp were 80 to 120 nm in diameter, limited by a unit membrane, and resembled ppv, visna virus, and other members of the oncornavirus family. some vlp seemed to have electron-dense nucleoids and external spikes. in neutrophils, vlp were observed budding into vacuoles; rarely, intravacuola ...1975167620
pathogenesis of in utero infection: experimental infection of five-week-old porcine fetuses with porcine parvovirus.injection of porcine parvovirus (ppv) into the allantoic fluid of 3 or 4 fetuses of each of 4 litters of ppv-immune gilts early in gestation (34 to 36 days) resulted in fetal maceration and mummification. a high concentration of virus demonstrated in many tissues of fetuses collected 1 week after initial intraallantoic exposure indicated extensive viral replication. progressively lesser amounts of virus were isolated from tissues of macerated and mummified fetuses collected after longer interval ...19751098529
elevated concentrations in serum immunoglobulins due to infection by ovine progressive pneumonia virus.sixty-seven serum samples were obtained from 2 sheep flocks. agar gel immunodiffusion (agid) was used to separate progressive pneumonia virus (ppv)-infected sheep from noninfected sheep by the presence of precipitating antibodies. immunoglobulin (ig), total protein, and albumin concentrations were then measured from all 67 sera to determine whether differences existed between ppv-infected and non-infected sheep. a significant difference (p less than 0.0005) was found in both total protein and ig ...1979110182
pathogenesis of porcine parvovirus infection: pathology and immunofluorescence in the foetus. 1977332722
experimental porcine parvovirus infection of foetal pigs resulting in abortion, histological lesions and antibody formation. 1977591653
porcine parvovirus: frequency of naturally occurring transplacental infection and viral contamination of fetal porcine kidney cell cultures.the frequency of naturally occurring transplacental infection of swine with porcine parvovirus (ppv) and one of the possible consequences of such infection--the presence of ppv in cell cultures prepared from fetal tissues--were investigated. transplacental infection was indicated by the presence of high titers of hemagglutination inhibiting (hi) antibody for ppv in serums of 0-day-old, hysterectomy-derived, colostrum-deprived pigs of 3 of 82 litters. all letters were farm-raised dams. moreover, ...1975163603
porcine parvovirus infection in ontario: incidence and diagnosis in herds with reproductive failures. 1979526907
a standardised haemagglutination inhibition test for porcine parvovirus antibody.basic variables of the haemagglutination inhibition (hi) test for porcine parvovirus antibody were investigated. nonspecific serum inhibitors were satisfactorily removed without loss of specific antibody when undiluted serum was adsorbed with 25 percent kaolin in borate saline at ph 9.0. natural haemagglutinins in test serums could be completely removed using 0.1 ml of packed erythrocytes to 0.6 ml of kaolin treated serums. adsorption of prediluted serum resulted in a depression of specific anti ...19761016168
experimental in utero infection of fetal pigs with a porcine utero infection of fetuses of six specific-pathogen-free large white sows at 35, 48, 55, 72, 99, and 105 days was studied. the fetuses were infected by direct inoculation of porcine parvovirus into the amniotic sac. the inoculation consisted of 0.25 ml of tissue culture fluid containing 10(5.5) mean tissue culture infective doses per ml of porcine parvovirus strain g10/1. fetuses of one uterus horn were infected, whereas fetuses in the opposite horn were given 0.25 ml of noninfected cell cult ...19751165118
a microneutralization test for the assay of porcine parvovirus antibody. 19751169929
prevalence of antibodies to porcine enteroviruses and porcine parvovirus in body fluids of fetal pigs from small vs large litters. 1976175042
[experiments to verify the plum pox virus (ppv) by communicating it on chenopodium foetidum schrad. (author's transl)]. 19751242554
[examinations concerning the range of host plants of the plum pox virus (ppv) (author's transl)]. 19751242553
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
[porcine parvovirus infection and stillbirth in swine. ii. sero-epizootiological survey (author's transl)]. 19751241629
[porcine parvovirus infection and stillbirth in swine. i. virus isolation from stillborn piglets (author's transl)]. 19751241628
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
observations on the epidemiology of porcine parvovirus.evidence presented suggests that porcine parvovirus is highly stable and infective. introduction of virus to susceptible herds results in 100% infection rate within the following 3 months. active immunity is associated with high persistent levels of haemagglutination-inhibitating (hi) antibody (greater than 256), piglets suckling immune sows acquiring hi titres between 10,000 and 40,000. loss of passive immunity, measured by hi, occurs in a majority of pigs between 14 and 26 weeks of age (mean 2 ...1976985234
immunoglobulins in porcine umbilical cord blood and maternal placenta.studies were made of the immunoglobulin (ig) in serums from umbilical cord of newborn pigs and maternal placenta. the neutralization test for porcine parvovirus and japanese encephalitis virus was carried out with the serum of the sow and that of the umbilical cord of the newborn pig. comparative studies of the serums from the dam and the umbilical cord were also done with gel filtration. of 20 umbilical cord serum samples, igg was seen in 5 samples (25%), iga in 1 sample (5%), and igm in 9 samp ...19761275337
fetal mummification associated with porcine parvovirus infection.a crossbred gilt farrowed 2 mummified fetuses at term, but subsequently developed uterine inertia and became listless. the remaining 5 fetuses of the litter (4 mummified and 1 normal appearing) were collected by hysterectomy. porcine parvovirus (ppv) was isolated from tissues of the mummified fetuses, and masses of viral antigen were detected throughout the same tissues when cryostat sections were examined by immunofluorescence microscopy. serum from the normal-appearing fetus of this litter had ...19751126862
experimental infection of 35, 50 and 60 day old pig foetuses with porcine parvovirus.foetuses of six seronegative gilts, two of which each respectively 35, 50 and 60 days pregnant, were inoculated intrauterinely with porcine parvovirus (ppv) and examined 7 and 11 days after inoculation. hi antibody was not detected in any of the foetuses although all but one gilt developed low levels of antibody. all but one of the foetuses inoculated with ppv died in utero prior to examination at 11 days after inoculation. infection also spread to non-inoculated litter mates. histological chang ...1978743053
reproductive failure in swine associated with maternal seroconversion for porcine parvovirus.reproductive failure occurred in a swine herd in which the epizootiology of enteroviruses and the porcine parvovirus were being studied. three virgin boars that were seropositive for the parvovirus were mated to seronegative, previously unmated gilts. the 11 gilts that farrowed had small litters, with high perinatal mortality. the remaining 12 gilts were marketed because of infertility, and the reproductive tracts were examined. pathologic findings included early embryonal death attributed to vi ...19751126861
histopathological changes of the brain in swine fetuses naturally infected with procine parvovirus.during a period from 1971 to 1972, some cases of stillbirth and abortion associated with porcine parvovirus infection were recognized in swine herds in japan. the brain was examined histopathologically in five stillborn piglets and four dead fetuses from which the parvoviruses had been isolated. similar histological changes were observed in all the piglets and fetuses, except one piglet which was free from recognizable lesions. the brain lesions were considered to belong to the category of menin ...19751121331
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
a current assessment of the role of porcine parvovirus as a cause of fetal porcine 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
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
pathogenesis of in utero infection: experimental infection of eight- and ten-week-old porcine fetuses with porcine parvovirus.selected numbers of fetuses in each of 4 pregnant gilts were exposed to a porcine parvovirus by injecting the virus into the allantoic fluid at gestation day 56 or 70. the fetuses were examined on postexposure day 7 or 14. when pregnancy was terminated, 2 of 15 exposed fetuses were dead. several fetuses tested at post-exposure day 14 had hemagglutination-inhibiting antibodies to porcine parvovirus. virus was detected most frequently and in highest concentration in the parenchymatous organs of th ...19751200446
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
isolation of porcine parvovirus from aborted piglets. 1977275675
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
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
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
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
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
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
porcine parvovirus in pig herds in southern africa.evidence of the presence of porcine parvovirus in southern africa is given and the diagnostic significance of this finding is discussed. minor abnormalities in the replication of the virus were observed.19751219104
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
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
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
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
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
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
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
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
development of a vaccine preventing parvovirus-induced reproductive failure in 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
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
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 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
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
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
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
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
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
molecular cloning of porcine parvovirus dna for the purpose of obtaining viral antigen synthesis in 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
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
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
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
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
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
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
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
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
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
[experimental studies on maedi-visna].in order to study pathogenicity of sheep lentiviruses, to obtain monospecific sera and to perfect elisa, 3 experiments with different strains were carried out for 4 yr. in expt 1, one clone only of a french maedi-visna strain (564-79) elicits a clear seroconversion in inoculated sheep. in expt 2, k1514 is more immunogenic than k796 and ppv: intratracheal route seems more efficient than intracerebral route. sheep infected by ts mutants (expt 3) are early positive as wild strain k796. nevertheless ...19882838220
parvovirus-like particles associated with diarrhea in unweaned piglets.numerous parvovirus-like particles, 18 to 26 nm in diameter, were detected by electron microscopy in the intestinal contents of two to three week old piglets with mild to severe diarrhea, in six quebec pig herds. hemagglutination of guinea pig and african green monkey red blood cells was obtained with clarified intestinal contents. two isolates were found to be antigenically related to porcine and canine parvoviruses, while another differed from the porcine parvovirus using the hemagglutination- ...19852412678
antigenic relationships among autonomous parvoviruses.the antigenic relatedness of minute virus of mice (mvm), kilham rat virus (kr), h-1 virus (h-1), haemorrhagic encephalopathy of rats virus (her), porcine parvovirus (ppv), canine parvovirus (cpv), feline panleukopenia virus (fpv), goose parvovirus (gpv) and bovine parvovirus (bpv) was studied by immunofluorescence microscopy (fa) and by serum neutralization (sn). an antigenically related group comprising mvm, kr, her, ppv, cpv and fpv was recognized by fa and most reactions within the group were ...19862432167
expression of the plum pox virus coat protein region in escherichia coli.a cdna complementary to the 3' end of plum pox virus (ppv) rna was sequenced. the sequence was investigated for the presumable coat protein cistron by computer-aided translation. a fragment containing the stop codon of the polyprotein gene and a putative virus-specific protease cleavage site was subcloned into an e. coli expression vector. it is shown by immunological analysis that the coat protein cistron is located within the subcloned region.19892655276
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 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
polarized entry of canine parvovirus in an epithelial cell line.the binding and uptake of canine parvovirus (cpv) in polarized epithelial cells were investigated by growing the cells on a permeable support and inoculating with the virus either from the apical or basolateral surface. binding of radiolabeled cpv occurred preferentially on the basolateral surface. in contrast, when a similar experiment was carried out on nonpolarized a72 cells, virus binding occurred regardless of the direction of virus input. binding appeared to be specific for cpv and could n ...19892657102
artificial cleavage site recognized by plum pox potyvirus protease in escherichia coli.a synthetic plum pox virus (ppv) nib-cp cleavage site was recognized by a ppv protease in an in vivo escherichia coli expression system. the presence of the natural nib-cp cleavage site did not affect processing at the artificial one. however, although both the proteases and the cleavage sites of ppv and tobacco etch virus show high sequence homology, a similar cassette from the tobacco etch virus nib-cp junction was not efficiently recognized by the ppv protease.19892657098
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
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
an enzyme-linked immunosorbent assay for detection of antibodies to porcine 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
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
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
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