| eosinophils, eosinophil ribonucleases, and their role in host defense against respiratory virus pathogens. | eosinophils remain among the most enigmatic of cells, as our appreciation of their detrimental activities--e.g., asthma and allergic disease--far outweighs our understanding of their beneficial effects. among the major secretory effector proteins of eosinophils are the ribonucleases eosinophil-derived neurotoxin (edn) and eosinophil cationic protein (ecp) in primates and their orthologs, the eosinophil-associated ribonucleases (ears) in rodents. the rapid diversification observed among these rib ... | 2001 | 11698487 |
| avian pneumoviruses and emergence of a new type in the united states of america. | avian pneumovirus (apv) primarily causes an upper respiratory disease recognized as turkey rhinotracheitis (trt) or swollen head syndrome (shs) in chickens. the virus was first isolated in south africa during the early 1970s and has subsequently been reported in europe, asia and south america. in february 1997, a serologically distinct apv isolate was officially reported in the usa following an outbreak of trt during the previous year. this was the first report of these virus types in the usa; t ... | 2000 | 11706845 |
| glucocorticoid administration accelerates mortality of pneumovirus-infected mice. | the use of glucocorticoids for the treatment of symptoms associated with respiratory syncytial virus (rsv) infection has been questioned. to evaluate the sequelae of glucocorticoid administration in the setting of pneumovirus infection in vivo, hydrocortisone was administered to mice infected with pneumonia virus of mice (pvm), a pneumovirus and natural rodent pathogen that is closely related to rsv and replicates the signs and symptoms of severe human rsv infection. results showed that hydrocor ... | 2001 | 11740726 |
| vaccination of turkeys with an avian pneumovirus isolate from the united states. | four-week-old poults obtained from avian pneumovirus (apv) antibody-free parents were vaccinated with different serial 10-fold dilutions of cell culture-propagated apv vaccine. the birds were vaccinated with 50 microl into each conjunctival space and nostril (total of 200 microl). each poult of each group was vaccinated in groups that received doses of 4 x 10(4), 4 x 10(3), 4 x 10(2), 4 x 10(1), or 4 x 10(0) 50% tissue culture infective dose (tcid50) of apv vaccine, respectively. respiratory sig ... | 2001 | 11785871 |
| isolation of avian pneumovirus from mallard ducks that is genetically similar to viruses isolated from neighboring commercial turkeys. | our earlier studies demonstrating avian pneumovirus (apv) rna in wild geese, sparrows, swallows, starlings and mallard ducks suggested that wild birds might be involved in the circulation of apv in the united states. to determine whether turkey virus can be transmitted to the free flying birds, we placed apv-negative mallard ducks next to a turkey farm experiencing a severe apv outbreak and in an area with a large population of waterfowls. the sentinel ducks did not develop clinical apv disease ... | 2002 | 11864753 |
| pathogenic and immunosuppressive effects of avian pneumovirus in turkeys. | avian pneumovirus (apv) causes a respiratory disease in turkeys. the virus has been associated with morbidity and mortality due to secondary infections. our objective was to determine if apv caused immunosuppression in the t-cell or b-cell compartments and to study the pathogenesis of the disease in apv maternal antibody-lacking 2-wk-old commercial turkeys. apv was administered by the eyedrop/intranasal route. observations were made for gross lesions, viral genome, and t-cell mitogenesis and cyt ... | 2002 | 11922327 |
| avian reovirus sigma c protein contains a putative fusion sequence and induces fusion when expressed in mammalian cells. | the biological functions of the structural protein sigma c, from avian reovirus strain ram-1, were investigated in this study. a putative fusion peptide in sigma c was recognized in the deduced amino acid sequence by homology with pneumovirus fusion sequences, and it was thus postulated that this protein may be involved in the formation of syncytia in cells infected with ram-1. the sigma c gene was cloned and expressed in mammalian (cos7) cells and the sigma c protein was found to induce syncyti ... | 1995 | 7747439 |
| efficacy of avian pneumovirus vaccines against an avian pneumovirus/escherichia coli o2:k1 dual infection in turkeys. | the clinical, pathological and microbiological outcome of a challenge with avian pneumovirus (apv) and escherichia coli o2:k1 was evaluated in turkeys vaccinated with an attenuated apv vaccine and with or without maternally derived antibodies. two groups of two-week-old poults, one with and one without maternally derived antibodies against apv, were vaccinated oculonasally with attenuated apv subtype a or b. a third group remained unvaccinated. eleven weeks later, the turkeys were inoculated int ... | 2002 | 11936883 |
| development and evaluation of an enzyme-linked immunosorbent assay for the detection of antibodies to avian pneumovirus. | the development and evaluation of an enzyme-linked immunosorbent assay (elisa) for the detection of antibodies to avian pneumovirus (apv) in chicken or turkey sera is described. the assay was capable of detecting serological responses as early as 11 days after chickens had been experimentally exposed to apv. the assay was evaluated by testing 4989 chicken or turkey sera from canada (a known apv-negative country) and by testing 1190 chicken or turkey sera assumed positive from evidence of other l ... | 1994 | 7702500 |
| molecular epidemiology of subgroup c avian pneumoviruses isolated in the united states and comparison with subgroup a and b viruses. | the avian pneumovirus (apv) outbreak in the united states is concentrated in the north-central region, particularly in minnesota, where more outbreaks in commercial turkeys occur in the spring (april to may) and autumn (october to december). comparison of the nucleotide and amino acid sequences of nucleoprotein (n), phosphoprotein (p), matrix (m), fusion (f), and second matrix (m2) genes of 15 u.s. apv strains isolated between 1996 and 1999 revealed between 89 and 94% nucleotide sequence identit ... | 2002 | 11980943 |
| pathogenesis of avian pneumovirus infection in turkeys. | avian pneumovirus (apv) is the cause of a respiratory disease of turkeys characterized by coughing, ocular and nasal discharge, and swelling of the infraorbital sinuses. sixty turkey poults were reared in isolation conditions. at 3 weeks of age, serum samples were collected and determined to be free of antibodies against apv, avian influenza, hemorrhagic enteritis, newcastle disease, mycoplasma gallisepticum, mycoplasma synoviae, mycoplasma meleagridis, ornithobacterium rhinotracheale, and borde ... | 2002 | 12014494 |
| infectious agents associated with respiratory disease in pheasants. | in a case-control study of the infectious agents associated with natural outbreaks of respiratory disease in pheasants, 28 batches of birds from sites affected by disease and eight batches of birds from unaffected sites were examined by six veterinary laboratories in england, wales and scotland, and tested for mycoplasmas, other bacteria and viruses. sinusitis was the commonest sign of disease and was associated with mycoplasma gallisepticum as detected by pcr in the trachea (p < 0.05) and conju ... | 2002 | 12054135 |
| reduced efficacy of hemorrhagic enteritis virus vaccine in turkeys exposed to avian pneumovirus. | avian pneumovirus (apv) is an immunosuppressive respiratory pathogen of turkeys. we examined the effect of apv infection on the vaccine efficacy of hemorrhagic enteritis virus (hev) vaccines. apv was inoculated in 2-wk-old turkeys. two or four days later, an attenuated hev vaccine (hevp30) or marble spleen disease virus (msdv) vaccine were administered. virulent hev challenge was given 19 days after hev vaccination. apv exposure compromised the ability of hevp30 and msdv to protect turkeys again ... | 2002 | 12061644 |
| experimental infection of turkeys with avian pneumovirus and either newcastle disease virus or escherichia coli. | avian pneumoviruses (apvs) are rna viruses responsible for upper respiratory disease in poultry. experimental infections are typically less severe than those observed in field cases. previous studies with apv and escherichia coli suggest this discrepancy is due to secondary agents. field observations indicate apv infections are more severe with concurrent infection by newcastle disease virus (ndv). in the current study, we examined the role of lentogenic ndv in the apv disease process. two-week- ... | 2002 | 12061652 |
| in vitro effects of some steroidal hormones on the replication of avian pneumovirus. | the effects of testosterone, oestradiol, progesterone and cortisone on the in vitro replication of avian pneumovirus in tracheal organ cultures (toc) were investigated. samples of cell-associated and cell-free virus from toc, grown in medium containing these hormones, were taken at selected intervals. progesterone and cortisone caused a slight increase in cell-associated virus. testosterone and oestradiol caused a slight delay and decrease in virus replication when compared with the controls. al ... | 2002 | 12069273 |
| new isolates of pneumonia virus of mice (pvm) from japanese rat colonies and their characterization. | two virus strains were isolated from the lungs of athymic rats and mice used as sentinel animals in 2 colonies of laboratory rats in japan in which antibodies to the pneumonia virus of mice (pvm) had been detected. the new isolates were identified as pvm by the following characteristics: rna virus, susceptibility to ether treatment, long filamentous viral structure in the cytoplasm of infected cells, and hemagglutinating activity in various erythrocytes, including those of mice and rats. in addi ... | 1995 | 7601231 |
| effect of an immunomodulator on the efficacy of an attenuated vaccine against avian pneumovirus in turkeys. | since 1997, avian pneumovirus (apv) has caused estimated annual losses of $15 million to the minnesota turkey industry. in order to develop an attenuated live vaccine against apv, we serially passaged a minnesota isolate of apv (apv/mn/turkey/1-a/97) in vitro in cell cultures for 41 passages. laboratory experiments with this high-passage virus (p41) indicated that the attenuated virus provided immunogenic protection to turkeys against challenge with virulent apv, although some birds showed mild ... | 2002 | 12243518 |
| pathogenicity, transmissibility, and tissue distribution of avian pneumovirus in turkey poults. | the pathogenicity, transmissibility, tissue distribution, and persistence of avian pneumovirus (apv) in turkey poults were investigated in three experiments. in the first experiment, we inoculated 2-wk-old commercial turkey poults oculonasally with apv alone or in combination with bordetella avium. in the dually infected group, clinical signs were more severe, the virus persisted longer, the bacteria invaded more respiratory tissues, and the birds had higher antibody titer than the group exposed ... | 2002 | 12243529 |
| comparison of enzyme-linked immunosorbent assays and virus neutralization test for detection of antibodies to avian pneumovirus. | two different whole-virus enzyme-linked immunosorbent assays (elisas), developed in ohio (oh) with apv/minnesota/turkey/2a/97 and in minnesota (mn) with apv/colorado/turkey/97, and the virus neutralization (vn) test were used to test 270 turkey serum samples from 27 minnesota turkey flocks for avian pneumovirus (apv) antibodies. in addition, 77 turkey serum samples and 128 ostrich serum samples from ohio were tested. none of the turkey samples from ohio had antibodies to apv by the vn test and o ... | 2002 | 12243535 |
| turkey rhinotracheitis virus: in vivo and in vitro polypeptide synthesis. | turkey rhinotracheitis (trt) virus is a paramyxovirus associated with recent outbreaks of acute respiratory disease in turkeys. on morphological criteria it resembles the pneumoviruses more than the other members of the paramyxovirus family. in this communication we report the identification of five virus-induced polypeptides in trt virus-infected bs-c-1 cells. the mr of these polypeptides were estimated as 38k, 35k, 30k, 19k and 15k from their electrophoretic mobility in sds-polyacrylamide 6 to ... | 1988 | 3356982 |
| characterization of a virus associated with turkey rhinotracheitis. | a virus associated with turkey rhinotracheitis was purified and its morphology and structural polypeptides were compared with those of the bovine, human and murine members of the genus pneumovirus. the isolate possessed surface projections 13 to 14 nm in length and a helical nucleocapsid 14 nm in diameter with a pitch of 7 nm. approximately seven presumed viral polypeptides were observed. their apparent molecular weights were 200 x 10(3) (200k), 84k, 54k, 42k, 37k, 31k and 14k; two of these, the ... | 1988 | 3356981 |
| pneumovirus-like characteristics of the mrna and proteins of turkey rhinotracheitis virus. | electronmicroscopy has indicated that turkey rhinotracheitis virus (trtv), the causative agent of an acute respiratory disease in turkeys, is a member of the paramyxoviridae family. to determine if trtv belongs to one of the three defined genera of this family (paramyxovirus, morbillivirus and pneumovirus) we have analysed the rna and proteins induced during replication of trtv in vero cells. following replication in the presence of actinomycin d 10 polyadenylated rna bands, ranging in mr from 0 ... | 1988 | 3195218 |
| experimental and field evaluation of a live vaccine against avian pneumovirus. | the attenuation of an avian pneumovirus (apv) isolate (apv/mn/turkey/1-a/97) by 63 serial passages in cell culture (seven in chicken embryo fibroblasts and 56 in vero cells) and its evaluation as a live attenuated vaccine in turkey poults is described. the birds were vaccinated with two different doses of attenuated virus (10(4.5) median tissue culture infectious dose (tcid(50))/ml and 10(2.5) tcid(50) /ml) at 2 weeks of age, and were challenged 2 weeks later with virulent apv. no clinical signs ... | 2002 | 12396339 |
| detection and differentiation of avian pneumoviruses (metapneumoviruses). | the available detection methods for avian pneumoviruses (turkey rhinotracheitis virus; genus metapneumovirus) in turkeys, domestic fowl and other species are reviewed. the advantages and disadvantages of virus isolation techniques, virus or genome (polymerase chain reaction) detection and serology are discussed. some of the problems likely to be encountered are considered, including the detection of yet to be discovered subtypes, as are the factors that are likely to influence the outcome of the ... | 2002 | 12396356 |
| replication and clearance of respiratory syncytial virus: apoptosis is an important pathway of virus clearance after experimental infection with bovine respiratory syncytial virus. | human respiratory syncytial virus is an important cause of severe respiratory disease in young children, the elderly, and in immunocompromised adults. similarly, bovine respiratory syncytial virus (brsv) is causing severe, sometimes fatal, respiratory disease in calves. both viruses are pneumovirus and the infections with human respiratory syncytial virus and brsv have similar clinical, pathological, and epidemiological characteristics. in this study we used experimental brsv infection in calves ... | 2002 | 12466134 |
| detection of avian pneumovirus in wild canada (branta canadensis) and blue-winged teal (anas discors) geese. | choanal cleft swab samples from 770 wild canada geese (branta canadensis) and 358 blue-winged teal (anas discors), captured for relocation or banding, were examined for the presence of avian pneumovirus (apv) rna by reverse transcription (rt)-polymerase chain reaction (pcr) and for virus isolation. the swab samples were pooled into groups of 5 or 10. sixty eight of 102 (66.7%) pooled goose samples were rt-pcr positive for apv rna. thirteen of 52 (25.0%) pooled blue-winged teal samples were rt-pc ... | 2002 | 12495069 |
| altered pathogenesis of severe pneumovirus infection in response to combined antiviral and specific immunomodulatory agents. | we report here the responses of mice with symptomatic pneumovirus infection to combined antiviral and specific immunomodulatory agents. mice infected with pneumonia virus of mice, a natural mouse pathogen that replicates the signs and symptoms of severe infection with respiratory syncytial virus (rsv), responded to the antiviral agent ribavirin when it was administered in the setting of endogenous (gene deletion) or exogenous (antibody-mediated) blockade of the mip-1alpha proinflammatory signali ... | 2003 | 12502841 |
| the mumps virus nucleocapsid mrna sequence and homology among the paramyxoviridae proteins. | the nucleotide sequence of mumps virus nucleocapsid protein (np) mrna has been determined from two overlapping cdna clones and confirmed by partial sequencing of the mrna and the genome. the mrna contains 1844 nucleotides excluding poly(a) and encodes a protein of 553 amino acids with a calculated molecular weight of 61,792. a comparison of the mumps virus nucleocapsid protein sequence with that of other paramyxoviruses revealed a moderate degree of homology (33.1%) with the newcastle disease vi ... | 1989 | 2718626 |
| immunity to avian pneumovirus infection in turkeys following in ovo vaccination with an attenuated vaccine. | fertile turkey eggs after 24 days of incubation were vaccinated in ovo with a commercial live attenuated subtype a avian pneumovirus (apv) vaccine. hatchability was not adversely affected. when a high dose (10 times maximum commercial dose) of vaccine was tested in maternal antibody negative (ma-) eggs, mild clinical signs developed in a small proportion of the poults for 1-4 days only. post-vaccination antibody titres at 3 weeks of age were significantly higher than those seen when the same dos ... | 2003 | 12615430 |
| sequence and in vitro expression of the m2 gene of turkey rhinotracheitis pneumovirus. | negative-stranded virion rna and oligonucleotide primers complementary to fusion (f) protein gene sequences were used to generate cdna clones, revealing that the gene 5'-proximal to the f protein corresponded to the m2 (22k) gene, as in respiratory syncytial (rs) virus. the transcription start signal, gggacaagu, was identical to that of the f and matrix (m) proteins of turkey rhinotracheitis virus (trtv). there were two sequences with the potential to function as transcription termination/poly(a ... | 1992 | 1607858 |
| susceptibility of an avian pneumovirus isolated from minnesota turkeys to physical and chemical agents. | survival characteristics of a minnesota avian pneumovirus (apv) isolated from a turkey nasoturbinate, propagated in tissue culture, and exposed to various physiochemical treatments were determined. these characteristics included survivability under various conditions. specifically, apv was viable at temperatures of -70 c and -20 c for over 26 wk, 4 c for less than 12 wk, 20 c for less than 4 wk, 37 c for 48 hr, and 50 c for less than 6 hr. in addition, apv survived 12 freeze/thaw cycles with no ... | 2000 | 10879914 |
| characterization of avian metapneumoviruses isolated in the usa. | avian pneumovirus (apv; officially known as turkey rhinotracheitis virus) is an emergent pathogen of birds in the usa that results in upper respiratory tract disease in turkeys. six years after the first outbreak in the usa, the disease continues to ravage turkey flocks, primarily in the state of minnesota. from 1997 to 2000, the industry recorded losses estimated at 15 million us dollars per annum. researchers have developed sensitive diagnostic techniques, including the enzyme-linked immunosor ... | 2002 | 12665110 |
| subtype b avian metapneumovirus resembles subtype a more closely than subtype c or human metapneumovirus with respect to the phosphoprotein, and second matrix and small hydrophobic proteins. | avian metapneumovirus (ampv) subtype b (ampv/b) nucleotide sequences were obtained for the phosphoprotein (p), second matrix protein (m2), and small hydrophobic protein (sh) genes. by comparison with sequences from other metapneumoviruses, ampv/b was most similar to subtype a ampv (ampv/a) relative to the us subtype c isolates (ampv/c) and human metapneumovirus (hmpv). strictly conserved residues common to all members of the pneumovirinae were identified in the predicted amino acid sequences of ... | 2003 | 12686426 |
| identification of amino acids that are critical to the processivity function of respiratory syncytial virus m2-1 protein. | the m2-1 protein of respiratory syncytial virus (rsv) is a transcription processivity factor that is essential for virus replication. the function of rsv m2-1 protein can be examined by using an rsvlacz minigenome assay in vitro since the expression of the lacz gene is dependent on m2-1. the m2-1 protein of pneumonia virus of mice (pvm), also a member of the pneumovirus genus, functions poorly in the rsvlacz minigenome assay despite conservation of the cys(3)-his(1) motif at its n terminus and a ... | 2003 | 12692207 |
| avian pneumovirus infection in minnesota turkeys: experimental reproduction of the disease. | avian pneumovirus (apv) is an emerging viral respiratory disease agent of turkeys in minnesota. clinical signs of apv infection include open mouth breathing, ocular and nasal discharge, and swelling of infraorbital sinuses. the virus spreads rapidly among flocks of susceptible turkeys and is associated with increased mortality rates. a flock of 11-wk-old turkeys experienced a respiratory problem characterized by coughing, sneezing, swollen sinuses, and nasal discharge. the reverse transcriptase- ... | 2000 | 10737667 |
| fusion protein predicted amino acid sequence of the first us avian pneumovirus isolate and lack of heterogeneity among other us isolates. | avian pneumovirus (apv) was first isolated from turkeys in the west-central us following emergence of turkey rhinotracheitis (trt) during 1996. subsequently, several apv isolates were obtained from the north-central us. matrix (m) and fusion (f) protein genes of these isolates were examined for sequence heterogeneity and compared with european apv subtypes a and b. among us isolates the m gene shared greater than 98% nucleotide sequence identity with only one nonsynonymous change occurring in a ... | 2000 | 10725547 |
| detection of antibodies to avian pneumovirus by a micro-indirect immunofluorescent antibody test. | a micro-indirect immunofluorescent antibody (micro-ifa) test with a 96-well, flat-bottomed microplate was developed for measuring avian pneumovirus (apv) antibodies. two japanese apv strains (mm-1, 8597/cv94) isolated at different places and times and vero cells were used for antigen preparation in this test. the test results were compared with those of a serum neutralization (sn) test. by the micro-ifa test, specific immunofluorescent antigens were observed in the cytoplasm of cells infected wi ... | 1999 | 10494406 |
| profilin is required for viral morphogenesis, syncytium formation, and cell-specific stress fiber induction by respiratory syncytial virus. | actin is required for the gene expression and morphogenesis of respiratory syncytial virus (rsv), a clinically important pneumovirus of the paramyxoviridae family. in hep-2 cells, rsv infection also induces actin stress fibers, which may be important in the immunopathology of the rsv disease. profilin, a major regulator of actin polymerization, stimulates viral transcription in vitro. thus, we tested the role of profilin in rsv growth and rsv-actin interactions in cultured cells (ex vivo). | 2003 | 12740026 |
| detection of sendai virus and pneumonia virus of mice by use of fluorogenic nuclease reverse transcriptase polymerase chain reaction analysis. | sendai virus may induce acute respiratory tract disease in laboratory mice and is a common contaminant of biological materials. pneumonia virus of mice (pvm) also infects the respiratory tract and, like sendai virus, may induce a persistent wasting disease syndrome in immunodeficient mice. reverse transcriptase-polymerase chain reaction (rt-pcr) assays have proven useful for detection of sendai virus and pvm immunodeficient animals and contaminated biomaterials. fluorogenic nuclease rt-pcr assay ... | 2003 | 12784851 |
| sequence analysis of the matrix (m2) protein gene of avian pneumovirus recovered from turkey flocks in the united states. | we here report the comparative sequence and phylogenetic analysis of the avian pneumovirus subgroup c (apv c) matrix (m2) gene of cell culture-adapted isolates and clinical samples. limited heterogeneity was observed among the m2 sequences, suggesting that diagnostic tests and vaccines against apv c are likely to exhibit broad cross-reactivity. | 2003 | 12791921 |
| detection and characterization of proteins encoded by the second orf of the m2 gene of pneumoviruses. | the nucleotide sequence of the m2 gene of pneumonia virus of mice (pvm) was determined. the sequence showed that the gene encoded a protein of 176 amino acids with a predicted molecular mass of 20165 da from a major orf, which is smaller than the equivalent proteins encoded by human, bovine and ovine respiratory syncytial (rs) viruses. the pvm m2 protein is conserved, having 41% similarity to the equivalent human rs virus protein. in common with the m2 genes of the rs viruses and avian pneumovir ... | 1999 | 10466798 |
| subgroup c avian metapneumovirus (mpv) and the recently isolated human mpv exhibit a common organization but have extensive sequence divergence in their putative sh and g genes. | the genes encoding the putative small hydrophobic (sh), attachment (g) and polymerase (l) proteins of the colorado isolate of subgroup c avian pneumovirus (apv) were entirely or partially sequenced. they all included metapneumovirus (mpv)-like gene start and gene end sequences. the deduced colorado sh protein shared 26.9 and 21.7 % aa identity with its counterpart in human mpv (hmpv) and apv subgroup a, respectively, but its only significant aa similarities were to hmpv. conserved features inclu ... | 2003 | 12867649 |
| comparison of f-, g- and n-based rt-pcr protocols with conventional virological procedures for the detection and typing of turkey rhinotracheitis virus. | fifty-six reverse transcriptions followed by a polymerase chain reaction (rt-pcr) were developed and/or assessed to detect and to type turkey rhinotracheitis virus (trtv). twenty-seven primers corresponding to sequences either common to both a and b viruses, or type-specific were respectively defined in the fusion (f), attachment (g) and nucleocapsid (n) proteins genes. only one n-based rt-pcr detected 21/21 trtvs isolated in four countries since 1985. molecular typing (rt-pcr) and antigenic typ ... | 1999 | 10446646 |
| development and evaluation of a blocking enzyme-linked immunosorbent assay for detection of avian metapneumovirus type c-specific antibodies in multiple domestic avian species. | the first cases of infection caused by avian metapneumoviruses (ampvs) were described in turkeys with respiratory disease in south africa during 1978. the causative agent was isolated and identified as a pneumovirus in 1986. ampvs have been detected in domestic nonpoultry species in europe, but tests for the detection of these viruses are not available in the united states. to begin to understand the potential role of domestic ducks and geese and wild waterfowl in the epidemiology of ampv, we ha ... | 2003 | 12904358 |
| molecular characterization of brazilian avian pneumovirus isolates: comparison between immunochemiluminescent southern blot and nested pcr. | avian pneumovirus (apv) causes acute respiratory tract infection both in turkeys (turkey rhinotracheitis) and chickens (swollen head syndrome (shs)) with sudden onset and rapid spread through the flocks. in this study, an immunochemiluminescent southern blot rt-pcr assay was employed to detect a f gene transcript of the apv in two european turkey isolates and two brazilian chicken isolates. limiting dilution pcr was carried out to compare the sensitivity of immunochemiluminescent southern blot a ... | 1999 | 10381093 |
| chimeric pneumovirus nucleocapsid (n) proteins allow identification of amino acids essential for the function of the respiratory syncytial virus n protein. | the nucleocapsid (n) protein of the pneumovirus respiratory syncytial virus (rsv) is a major structural protein which encapsidates the rna genome and is essential for replication and transcription of the rsv genome. the n protein of the related virus pneumonia virus of mice (pvm) is functionally unable to replace the rsv n protein in a minigenome replication assay. using chimeric proteins, in which the immediate c-terminal part of the rsv n protein was replaced with the equivalent region of the ... | 2003 | 13679601 |
| investigation into avian pneumovirus persistence in poults and chicks using cyclosporin a immunosuppression. | one-day-old poults or two-week old chicks were infected oculonasally with avian pneumovirus. cloacal swabs were collected for virus isolation as were selected tissues (harderian gland, turbinates, trachea, lungs and kidneys) from birds killed at regular intervals up to 33 days post infection (p.i.) for poults, and up to 40 days p. i. for chicks. in an attempt to induce virus re-excretion, the t-cell-suppressor cyclosporin a (csa) was given for 12 days starting from three weeks p.i. in poults and ... | 1999 | 10208895 |
| avian pneumovirus and its survival in poultry litter. | the survival of avian pneumovirus (apv) in turkey litter was studied at different temperature (room temperature, [approximately 22-25 c], 8 c, and -12 c) conditions. built-up turkey litter from a turkey breeder farm known to be free of apv was obtained and was divided into two portions. one portion was sterilized by autoclaving and the other portion was kept nonautoclaved. both samples were inoculated with a vero cell-propagated minnesota isolate of apv subtype c (apv/mn2a) with a titer of 10(5) ... | 2003 | 14562910 |
| sequence polymorphism of the predicted human metapneumovirus g glycoprotein. | the putative g glycoprotein genes of 25 human metapneumovirus (hmpv) field isolates obtained during five consecutive epidemic seasons (1997 to 2002) were sequenced. sequence alignments identified two major genetic groups, designated groups 1 and 2, and two minor genetic clusters within each major group, designated subgroups a and b. extensive nucleotide and deduced amino acid sequence variability was observed, consisting of high rates of nucleotide substitutions, use of alternative transcription ... | 2004 | 14993653 |
| human respiratory syncytial virus matrix protein is an rna-binding protein: binding properties, location and identity of the rna contact residues. | the human respiratory syncytial virus (hrsv) matrix (m) protein is a structural internal membrane protein. here we have shown that, like its orthomyxovirus and rhabdovirus counterparts, it has rna-binding capacity, as determined by retardation of (32)p-labelled riboprobes in gel electrophoresis, cross-linking with uv light and northern-western assays. its binding to rna was neither sequence-specific nor showed a length requirement, although it had cooperative kinetics with a k(d) of 25 nm and pr ... | 2004 | 14993657 |
| respiratory syncytial virus, pneumonia virus of mice, and influenza a virus differently affect respiratory allergy in mice. | respiratory viral infections in early childhood may interact with the immune system and modify allergen sensitization and/or allergic manifestations. in mice, respiratory syncytial virus (rsv) infection during allergic provocation aggravates the allergic t helper (th) 2 immune response, characterized by the production of il-4, il-5, and il-13, and inflammatory infiltrates. however, it is unclear whether the rsv-enhanced respiratory allergic response is a result of non-specific virus-induced dama ... | 2004 | 15005745 |
| control of nonsegmented negative-strand rna virus replication by sirna. | our laboratory provided the first proof-of-concept that double-stranded short interfering rna (ds-sirna) can act as potent and specific antiviral agents. designed against specific mrnas of nonsegmented negative-stranded rna (nnr) viruses, sirnas abrogated expression of the corresponding viral proteins, and generated the predicted viral phenotypes. knockdown was demonstrated across different genera: respiratory syncytial virus (rsv), a pneumovirus; vesicular stomatitis virus (vsv), a rhabdovirus; ... | 2004 | 15068877 |
| effects of bacterial coinfection on the pathogenesis of avian pneumovirus infection in turkeys. | four- and nine-week-old poults were inoculated with cell culture propagated avian pneumovirus (apv) into each conjunctival space and nostril, followed by inoculation 3 days later with escherichia coli, bordetella avium (ba), or ornithobacterium rhinotracheale or a mixture of all three (ebo). clinical signs were evaluated on days 3, 5, 7, 9, 11, and 14 postinoculation (pi) of apv. the poults were euthanatized on days 2, 4, 6, 10, and 14 pi, and blood and tissues were collected. the poults that re ... | 2004 | 15077796 |
| cold-adapted strain of avian pneumovirus as a vaccine in one-day-old turkeys and the effect of inoculation routes. | to determine the optimum route of vaccination, we inoculated 1-day-old turkeys with a cold-adapted strain of avian pneumovirus (apv) by oculonasal, oral, or aerosol route. another two groups served as nonvaccinated-challenged and nonvaccinated-nonchallenged groups. birds in all vaccinated and nonvaccinated-challenged groups were challenged with virulent apv 3 wk postvaccination. after challenge, no vaccinated bird developed clinical signs or virus shedding, whereas nonvaccinated-challenged birds ... | 2004 | 15077809 |
| animal pneumoviruses: molecular genetics and pathogenesis. | pneumoviruses are single-stranded, negative-sense, nonsegmented rna viruses of the family paramyxoviridae, subfamily pneumovirinae, and include pathogens that infect humans (respiratory syncytial virus and human metapneumovirus), domestic mammals (bovine, ovine, and caprine respiratory syncytial viruses), rodents (pneumonia virus of mice), and birds (avian metapneumovirus). among the topics considered in this review are recent studies focused on the roles of the individual virus-encoded componen ... | 2004 | 15084507 |
| matrix protein gene nucleotide and predicted amino acid sequence demonstrate that the first us avian pneumovirus isolate is distinct from european strains. | avian pneumovirus (apv) is the etiological agent of turkey rhinotracheitis (trt). outbreaks of trt first occurred in the us during may, 1996 and continued through june, 1997. this is the first report of these virus types in the us that was previously considered exotic to the us and canada. the us isolate, apv/co, was replicated in chick embryo fibroblasts (cef) and poly-a rna from apv/co infected cef cells was purified for cdna synthesis. degenerate oligonucleotide primers were used to amplify n ... | 1998 | 9879761 |
| antigenic and genetic variability of human metapneumoviruses. | human metapneumovirus (hmpv) is a member of the subfamily pneumovirinae within the family paramyxo- viridae. other members of this subfamily, respiratory syncytial virus and avian pneumovirus, can be divided into subgroups on the basis of genetic or antigenic differences or both. for hmpv, the existence of different genetic lineages has been described on the basis of variation in a limited set of available sequences. we address the antigenic relationship between genetic lineages in virus neutral ... | 2004 | 15200856 |
| significance of interactions between escherichia coli and respiratory pathogens in layer hen flocks suffering from colibacillosis-associated mortality. | this study aimed to examine the significance of interactions between escherichia coli and various respiratory pathogens during outbreaks of colibacillosis-associated mortality in layer hen flocks under field conditions. for this purpose, a case-control study involving 20 control flocks with baseline mortality and 20 flocks with increased mortality due to e. coli septicaemia and polyserositis, was conducted. in each colibacillosis flock, blood samples were taken from 20 hens at the onset of clini ... | 2004 | 15223556 |
| microwave or autoclave treatments destroy the infectivity of infectious bronchitis virus and avian pneumovirus but allow detection by reverse transcriptase-polymerase chain reaction. | a method is described for enabling safe transit of denatured virus samples for polymerase chain reaction (pcr) identification without the risk of unwanted viable viruses. cotton swabs dipped in avian infectious bronchitis virus (ibv) or avian pneumovirus (apv) were allowed to dry. newcastle disease virus and avian influenza viruses were used as controls. autoclaving and microwave treatment for as little as 20 sec destroyed the infectivity of all four viruses. however, both ibv and apv could be d ... | 2004 | 15223557 |
| towards the routine application of nucleic acid technology for avian disease diagnosis. | the use of nucleic acid technology (polymerase chain reaction, probing, restriction fragment analysis and nucleotide sequencing) in the study of avian diseases has largely been confined to fundamental analysis and retrospective studies. more recently these approaches have been applied to diagnosis and what one might call real-time epidemiological studies on chickens and turkeys. at the heart of these approaches is the identification and characterisation of pathogens based on their genetic materi ... | 1997 | 9276989 |
| genetic variability of the g glycoprotein gene of human metapneumovirus. | human metapneumovirus (hmpv) has been associated with respiratory illnesses like those caused by human respiratory syncytial virus (hrsv) infection. similar to other pneumoviruses, genetic diversity has been reported for hmpv. little information is currently available on the genetic variability of the g glycoprotein (g), which is the most variable gene in rsv and avian pneumovirus. the complete nucleotide sequences of the g open reading frame (orf) of 24 canadian hmpv isolates were determined. p ... | 2004 | 15297494 |
| avian rhinotracheitis. | turkey rhinotracheitis, now commonly termed avian pneumovirus (apv) infection, is associated with serious welfare and economic problems in susceptible populations of turkeys and probably also of chickens. the infection principally affects the upper respiratory tract, although egg-laying performance may also be affected in breeding turkeys. secondary infections exacerbate the effects of the primary virus infection. the virus persists for only a short time both in the host and in the environment a ... | 2000 | 10935282 |
| nuclear heat shock response and novel nuclear domain 10 reorganization in respiratory syncytial virus-infected a549 cells identified by high-resolution two-dimensional gel electrophoresis. | the pneumovirus respiratory syncytial virus (rsv) is a leading cause of epidemic respiratory tract infection. upon entry, rsv replicates in the epithelial cytoplasm, initiating compensatory changes in cellular gene expression. in this study, we have investigated rsv-induced changes in the nuclear proteome of a549 alveolar type ii-like epithelial cells by high-resolution two-dimensional gel electrophoresis (2de). replicate 2d gels from uninfected and rsv-infected nuclei were compared for changes ... | 2004 | 15479789 |
| development of a reverse-genetics system for avian pneumovirus demonstrates that the small hydrophobic (sh) and attachment (g) genes are not essential for virus viability. | avian pneumovirus (apv) is a member of the genus metapneumovirus of the subfamily pneumovirinae. this study describes the development of a reverse-genetics system for apv. a minigenome system was used to optimize the expression of the nucleoprotein, phosphoprotein, m2 and large polymerase proteins when transfected into vero cells under the control of the bacteriophage t7 promoter. subsequently, cdna was transcribed from the virion rna to make a full-length antigenome, which was also cloned under ... | 2004 | 15483235 |
| the chemokine macrophage-inflammatory protein-1 alpha and its receptor ccr1 control pulmonary inflammation and antiviral host defense in paramyxovirus infection. | in this work, we explore the responses of specific gene-deleted mice to infection with the paramyxovirus pneumonia virus of mice (pvm). we have shown previously that infection of wild type mice with pvm results in pulmonary neutrophilia and eosinophilia accompanied by local production of macrophage-inflammatory protein-1 alpha (mip-1 alpha). here we examine the role of mip-1 alpha in the pathogenesis of this disease using mice deficient in mip-1 alpha or its receptor, ccr1. the inflammatory resp ... | 2000 | 10946298 |
| reduced clearance of respiratory syncytial virus infection in a preterm lamb model. | respiratory syncytial virus (rsv) causes significant respiratory disease in children worldwide. for the study of severe rsv disease seen in preterm infants, a suitable animal model is lacking. the novel hypothesis of this study was that preterm lambs are susceptible to bovine rsv (brsv) infection, an analogous pneumovirus with ruminant host specificity, and that there would be age-dependent differences in select rsv disease parameters. during rsv infection, preterm lambs had elevated temperature ... | 2004 | 15555538 |
| specific detection of avian pneumovirus (apv) us isolates by rt-pcr. | this report details the development of an rt-pcr assay for the specific detection of us isolates of avian pneumovirus (apv). of the several primer pairs tested, two sets of primers derived from the matrix gene of apv were able to specifically detect the viral rna of apv. the nucleotide sequence comparison of the pcr products of apv isolates from minnesota suggested that these viruses were closely related to the colorado strain of apv, but were distinct from subtypes a and b european isolates of ... | 2000 | 10948996 |
| animal models for studying respiratory syncytial virus infection and its long term effects on lung function. | human respiratory syncytial virus (hrsv) infection causes a spectrum of illnesses ranging from mild infection to life-threatening bronchiolitis and respiratory failure. human studies on the pathogenesis of rsv infection are invaluable, but animal models permit advances with the use of experimental strategies that would be inappropriate in human studies. | 2004 | 15577578 |
| inhibition of interferon-mediated antiviral responses by influenza a viruses and other negative-strand rna viruses. | | 2001 | 11162793 |
| design, validation, and absolute sensitivity of a novel test for the molecular detection of avian pneumovirus. | this study describes attempts to increase and measure sensitivity of molecular tests to detect avian pneumovirus (apv). polymerase chain reaction (pcr) diagnostic tests were designed for the detection of nucleic acid from an a-type apv genome. the objective was selection of pcr oligonucleotide combinations, which would provide the greatest test sensitivity and thereby enable optimal detection when used for later testing of field materials. relative and absolute test sensitivities could be determ ... | 2004 | 15586577 |
| the pneumonia virus of mice infection model for severe respiratory syncytial virus infection: identifying novel targets for therapeutic intervention. | pneumonia virus of mice (pvm) is the first infection model that replicates features of severe human respiratory syncytial virus (hrsv) disease in the mouse. the pvm model has highlighted the importance of inflammation to the pathogenesis of severe disease, demonstrating that the inflammatory response remains active and acute even when virus replication ceases in response to appropriate antiviral therapy. the fact that the inflammatory response continues and is not completely linked to ongoing vi ... | 2005 | 15626452 |
| a multiplex reverse transcription-polymerase chain reaction assay for newcastle disease virus and avian pneumovirus (colorado strain). | newcastle disease virus (ndv) and avian pneumovirus (apv) cause newcastle disease and rhinotracheitis respectively, in turkeys. both of these viruses infect the respiratory system. a one-tube, multiplex, reverse transcription-polymerase chain reaction (rt-pcr) assay for the detection of both ndv and colorado strain of apv (apv-col) was developed and evaluated. the primers, specific for each virus, were designed from the matrix protein gene of apv-col and the fusion protein gene of ndv to amplify ... | 2000 | 11195650 |
| protective efficacy of high-passage avian pneumovirus (apv/mn/turkey/1-a/97) in turkeys. | a u.s. isolate of avian pneumovirus (apv), apv/mn/turkey/1-a/97, was attenuated by serial cell culture passages in chicken embryo fibroblasts (seven passages) and vero cells (34 passages). this virus was designated as apv passage 41 (p41) and was evaluated for use as a live vaccine in commercial turkey flocks. the vaccine was inoculated by nasal and ocular routes in 2-to-4-wk-old turkeys in 10 turkey flocks, each with 20,000-50,000 birds. only 2 birds per 1000 birds were inoculated in each flock ... | 2001 | 11569731 |
| evaluation of five different antigens in enzyme-linked immunosorbent assay for the detection of avian pneumovirus antibodies. | five different antigens were evaluated in enzyme-linked immunosorbent assay (elisa) tests for the detection of avian pneumovirus (apv) antibodies. two of the 5 antigens were prepared from recent apv isolates from minnesota. the 2 older isolates were passage 63 of a strain currently used as a live, attenuated vaccine and a colorado strain isolated for the first time in the united states and currently used in an elisa test. the fifth antigen is based on an apv recombinant n-protein. basic paramete ... | 2005 | 15690946 |
| persistence of mycoplasma gallisepticum in chickens after treatment with enrofloxacin without development of resistance. | the ability of the avian pathogen mycoplasma gallisepticum to persist despite fluoroquinolone treatment was investigated in chickens. groups of specific pathogen free chickens were experimentally infected with m. gallisepticum and treated with enrofloxacin at increasing concentrations up to the therapeutic dose. when m. gallisepticum could no longer be re-isolated from chickens, birds were stressed by inoculation of infectious bronchitis virus or avian pneumovirus. although m. gallisepticum coul ... | 2005 | 15737482 |
| key role of chlamydophila psittaci on belgian turkey farms in association with other respiratory pathogens. | two hundred turkey sera from eight belgian and two french farms were tested for the presence of antibodies against avian pneumovirus (apv), ornithobacterium rhinotracheale (ort), mycoplasma gallisepticum, mycoplasma meleagridis and chlamydophila psittaci. at slaughter, c. psittaci, apv and ort antibodies were detected in 94, 34 and 6.5% of the turkeys, respectively. no antibodies against m. gallisepticum or m. meleagridis were present. additionally, turkeys on three belgian farms were examined f ... | 2005 | 15795081 |
| neonatal avian pneumovirus infection in commercial turkeys. | eleven market turkey flocks developed a respiratory disease characterized by coughing, swollen sinuses and nasal discharge. these symptoms first appeared between 3 and 16 days of age. avian pneumovirus (apv) rna was detected by reverse transcriptase (rt)-polymerase chain reaction (pcr) in six of six flocks tested. apv was detected by immunohistochemistry in turbinates of three of three affected flocks tested. virus isolation attempts were negative. ten of 11 flocks became seropositive on the apv ... | 2002 | 11922343 |
| rapid detection of avian pneumovirus in tissue culture by microindirect immunofluorescence test. | an indirect immunofluorescence (ifa) test with a 96-well, flat-bottomed microplate was developed to detect avian pneumovirus (apv) antigen in vero cell cultures. samples of nasal turbinates and swabs from infraorbital sinuses and trachea were collected from 4-week-old poults experimentally inoculated with apv. the apv titers by tissue culture ifa staining were compared with that of visual reading of cytopathic effect (cpe). the ability of ifa staining to detect apv antigen correlated well with v ... | 2002 | 11939343 |
| inflammatory responses to pneumovirus infection in ifn-alpha beta r gene-deleted mice. | pneumonia virus of mice (pvm; family paramyxoviridae) is a natural pathogen of rodents that reproduces important clinical features of severe respiratory syncytial virus infection in humans. as anticipated, pvm infection induces transcription of ifn antiviral response genes preferentially in wild-type over ifn-alphabetar gene-deleted (ifn-alphabetar-/-) mice. however, we demonstrate that pvm infection results in enhanced expression of eotaxin-2 (ccl24), thymus and activation-regulated chemokine ( ... | 2005 | 16177121 |
| differential expression of proinflammatory cytokine genes in vivo in response to pathogenic and nonpathogenic pneumovirus infections. | pneumonia virus of mice (pvm; paramyxoviridae, subfamily pneumovirinae) is an important pathogen for the study of physiologically relevant acute inflammatory responses in rodent hosts. in contrast to the severe symptomatology observed in response to infection with pvm strain j3666, infection with strain 15 resulted in few clinical symptoms, limited cellular inflammatory response, and no production of macrophage inflammatory protein-1alpha or monocyte chemoattractant peptide (mcp)-1. microarray a ... | 2002 | 12089656 |
| subtyping of new brazilian avian metapneumovirus isolates from chickens and turkeys by reverse transcriptase-nested-polymerase chain reaction. | the aim of this study was to improve a reverse transcriptase (rt)-nested-polymerase chain reaction (pcr) able to differentiate avian pneumovirus (apv) subtypes a and b, and to characterize new brazilian isolates. representative apv strains and clinical field samples from chickens and turkey flocks were amplified in the chicken embryo-related cell line. viral rna was extracted from harvested cells, and submitted to cdna synthesis. the primers utilized for rt-pcr were compatible with the g gene of ... | 2005 | 16191694 |
| antigenic cross-reactivity among avian pneumoviruses of subgroups a, b, and c at the matrix but not nucleocapsid proteins. | earlier findings from our laboratory based on analysis of nucleotide and predicted amino acid sequence identities of 15 avian pneumoviruses (apvs) isolated from the united states (subgroup c) demonstrated that the viruses were phylogenetically separated from the european subgroup a and subgroup b viruses. here, we investigated whether viruses from the three subgroups were cross-reactive by testing field sera positive for each of the apv subgroups in an enzyme-linked immunosorbent assay (elisa) t ... | 2002 | 12243541 |
| activation and inactivation of antiviral cd8 t cell responses during murine pneumovirus infection. | pneumonia virus of mice (pvm) is a natural pathogen of mice and has been proposed as a tractable model for the replication of a pneumovirus in its natural host, which mimics human infection with human respiratory syncytial virus (rsv). pvm infection in mice is highly productive in terms of virus production compared with the situation seen with rsv in mice. because rsv suppresses cd8 t cell effector function in the lungs of infected mice, we have investigated the nature of pvm-induced cd8 t cell ... | 2005 | 16272314 |
| seroprevalence of human metapneumovirus in japan. | a new human pneumovirus, provisionally designated human metapneumovirus, was discovered by dutch researchers. we examined 142 serum samples from the general population aged from 1 month to 35 years in japan for human metapneumovirus antibody by indirect immunofluorescence assays using human metapneumovirus-infected monkey kidney cells. the overall prevalence of human metapneumovirus infection was 72.5%. the seropositive rate was lowest in the age group of 6 months to 1 year and gradually increas ... | 2003 | 12696118 |
| lack of antigenic relationships between avian pneumovirus and four avian paramyxoviruses. | avian paramyxoviruses (pmvs) and avian pneumovirus (apv) belong to the family paramyxoviridae. antigenic relationships between pmvs were shown previously, hence, this study was designed to investigate possible antigenic relationships between apv and four avian pmvs (pmv-1, pmv-2, pmv-3, and pmv-7). enzyme-linked immunosorbent assay (elisa), hemagglutination inhibition (hi) test, and virus neutralization (vn) test in chicken embryos and in vero cells were used. the hi test was performed with the ... | 2003 | 12713174 |
| deduced amino acid sequence of the small hydrophobic protein of us avian pneumovirus has greater identity with that of human metapneumovirus than those of non-us avian pneumoviruses. | we report here the nucleotide and deduced amino acid (aa) sequences of the small hydrophobic (sh) gene of the avian pneumovirus strain colorado (apv/co). the sh gene of apv/co is 628 nucleotides in length from gene-start to gene-end. the longest orf of the sh gene encoded a protein of 177 aas in length. comparison of the deduced aa sequence of the sh protein of apv/co with the corresponding published sequences of other members of genera metapneumovirus showed 28% identity with the newly discover ... | 2003 | 12727346 |
| transcriptional analysis of the response of poultry species to respiratory pathogens. | respiratory tract diseases are the single most important cause of economic loss due to infections among poultry populations worldwide. however, the molecular mechanisms of the host response to infections remain unknown. here, we review the literature and describe the adoption of a conceptually simple approach to understand the genetic and biochemical responses of host cells during infection with respiratory pathogens, such as avian pneumovirus (apv). the strategy that we have adopted integrates ... | 2003 | 12817442 |
| the cytoplasmic domain of the f protein of human respiratory syncytial virus is not required for cell fusion. | the cytoplasmic domains of the fusion proteins encoded by several viruses play a role in cell fusion and contain sites for palmitoylation associated with viral protein trafficking and virus assembly. the fusion (f) protein of human respiratory syncytial virus (hrsv) has a predicted cytoplasmic domain of 26 residues containing a single palmitoylated cysteine residue that is conserved in bovine rsv f protein, but not in the f proteins of other pneumoviruses such as pneumonia virus of mice, human m ... | 2006 | 16432027 |
| suppression of pattern-recognition receptor tlr4 sensing does not alter lung responses to pneumovirus infection. | toll-like receptors (tlr) are an important component in the innate immune response to a wide variety of pathogens. recently, a series of studies has addressed the hypothesis that tlr4 also participates in the host innate response against respiratory syncytial virus (rsv), the leading cause of lower respiratory tract infections in infants and young children. in most of the studies available, rsv, which is not a natural pathogen of mice, has been systematically used in mouse models of human bronch ... | 2006 | 16458035 |
| duration of immunity engendered by a single dose of a cold-adapted strain of avian pneumovirus. | the duration of immunity after a single dose of a cold-adapted strain of avian pneumovirus (apv) was studied. turkeys were vaccinated at 1 wk of age and challenged with virulent virus 3, 7, 10, and 14 wk later. nonvaccinated groups were also challenged at the same times. no clinical signs were observed in the vaccinated birds after vaccination or after any challenge. no viral rna was shed by the vaccinated birds after any challenge. the nonvaccinated birds shed viral rna after all challenges. av ... | 2006 | 16548335 |
| differential resistance/susceptibility patterns to pneumovirus infection among inbred mouse strains. | respiratory syncytial virus (rsv) is a prominent cause of airway morbidity in children under 1 yr of age. it is assumed that host factors influence the severity of the disease presentation and thus the need for hospitalization. as a first step toward the identification of the underlying genes involved, this study was undertaken to establish whether inbred mouse strains differ in susceptibility to pneumonia virus of mice (pvm), the murine counterpart of rsv, which has been shown to accurately mim ... | 2006 | 16556725 |
| respiratory dysfunction and proinflammatory chemokines in the pneumonia virus of mice (pvm) model of viral bronchiolitis. | we explore relationships linking clinical symptoms, respiratory dysfunction, and local production of proinflammatory chemokines in the pneumonia virus of mice (pvm) model of viral bronchiolitis. with a reduced inoculum of this natural rodent pathogen, we observe virus clearance by day 9, while clinical symptoms and respiratory dysfunction persist through days 14 and 17 postinoculation, respectively. via microarray and elisa, we identify expression profiles of proinflammatory mediators mip-1alpha ... | 2006 | 16563455 |
| attempts to improve on a challenge model for subtype c avian pneumovirus. | respiratory disease caused by avian pneumovirus (apv) has a strong negative impact on the economy of the turkey industry in many countries. progress in developing vaccines against this infection in the us has been slow partly because of the lack of a consistent challenge model to conduct vaccine efficacy studies. this study was designed to determine whether in vivo passages of a us isolate of apv, designated subtype c (apv-c), would increase virus virulence, leading to consistent clinical signs ... | 2006 | 16595303 |
| stimulation of pneumovirus-specific cd8+ t-cells using a non-toxic recombinant ricin delivery system. | internalisation of the plant toxin ricin occurs by retrograde transport which delivers the toxin to the er where it intersects with the mhc class i system for peptide antigen display. here, we describe the generation of an inactivated, non-toxic, ricin molecule fused to a peptide which elicits a cd8+ t-cell response in mice directed against pneumonia virus of mice, a pneumovirus related to human respiratory syncytial virus. the ricin fusion elicited a significant t-cell response when delivered b ... | 2007 | 16650896 |
| presence of avian pneumovirus subtypes a and b in japan. | four avian pneumovirus (apv) isolates from chickens clinically diagnosed with swollen head syndrome were genetically characterized as to the subtypes of the virus in japan. the results of reverse transcriptase-polymerase chain reactions based on subtype-specific primers and direct sequence analysis of g genes indicated subtypes a and b but not c or d of apv were present in japan. several routes or sources are conceivable for apv to invade into japan. | 2003 | 12887210 |
| seroprevalence of avian influenza virus, infectious bronchitis virus, reovirus, avian pneumovirus, infectious laryngotracheitis virus, and avian leukosis virus in nigerian poultry. | eight poultry farms in nigeria, including chickens from nine breeder, 14 broiler, 28 pullet, 11 layer, and three cockerel flocks, were tested for antibody seroprevalence to the following poultry viruses of potential economic importance: infectious bronchitis virus (ibv), avian reovirus, avian pneumovirus (apv), infectious laryngotracheitis virus (iltv), avian influenza virus (aiv), and avian leukosis virus (alv). serum samples were collected between 1999 and 2004 and were tested for antibodies u ... | 2006 | 16863071 |
| diminished expression of an antiviral ribonuclease in response to pneumovirus infection in vivo. | the mouse eosinophil-associated ribonucleases (mears) are species specific, divergent orthologs of the human antiviral rnase a ribonucleases, eosinophil-derived neurotoxin (rnase 2) and eosinophil cationic protein (rnase 3). we show here that mear 2 is also an antiviral ribonuclease, as micromolar concentrations promote a approximately sixfold reduction in the infectivity of pneumonia virus of mice (pvm) for target respiratory epithelial cells in vitro. although initially identified as a compone ... | 2003 | 12927308 |
| mucosal inoculation with an attenuated mouse pneumovirus strain protects against virulent challenge in wild type and interferon-gamma receptor deficient mice. | protective mechanisms underlying the responses to mucosal vaccination are not yet clearly defined. using the natural mouse pneumovirus pathogen, pneumonia virus of mice (pvm), we explore responses of wild type and interferon-gamma (ifngamma) receptor gene-deleted mice to virulent challenge after mucosal vaccination with an attenuated virus strain. serum neutralizing antibodies develop after intranasal inoculation with 30 pfu of attenuated, replication-competent pvm strain 15, which correlate wit ... | 2007 | 17052820 |
| interaction between a live avian pneumovirus vaccine and two different newcastle disease virus vaccines in broiler chickens with maternal antibodies to newcastle disease virus. | broiler chicks with maternal antibodies to newcastle disease virus (ndv) but none to avian metapneumovirus (apv) were divided into six groups. one group was kept as an unvaccinated control group. three of the other groups were vaccinated at 1 day old with live apv vaccine or one of two live ndv vaccines (vg/ga or hb1). the remaining two groups received the apv vaccine in combination with either of the two ndv vaccines at 1 day old. at intervals after vaccination for up to 42 days, distribution o ... | 2006 | 17121730 |
| seroprevalence of avian pneumovirus in minnesota turkeys. | avian pneumovirus (apv) causes respiratory tract infection in turkeys and was first seen in the united states in colorado in late 1996. in early 1997, the disease was recognized in minnesota and caused estimated losses of up to 15 million dollars per year. this virus has not been reported in the other turkey producing states. we here report the seroprevalence of apv in minnesota from august 1998 to july 2002. the average rate of seroprevalence has been 36.3% (range = 14.2%-64.8%). a seasonal bia ... | 2003 | 14562899 |