PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “NEWCASTLE DISEASE VIRUS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

Primaquine diphosphate: inhibition of Newcastle disease virus replication.

The response of Newcastle disease virus replication to primaquine, an antimalarial drug, was examined in chicken embryo cells (CEC). Virus-induced hemadsorption was completely inhibited by 250 mug of primaquine per ml. At lower concentrations, hemadsorption inhibition was dose dependent. Primaquine retarded virus-induced redistribution of receptor sites on the host cell plasma membrane as shown by the failure of infected, drug-treated CEC to be agglutinated with concanavalin A. The production of infectious progeny virus was substantially inhibited by the addition of primaquine at various times postinfection. When the drug was added early in the virus replication cycle, viral ribonucleic acid (RNA) synthesis was inhibited; however, when the drug was added late in the cycle, stimulation of RNA synthesis was observed. Primaquine was also shown to retard the incorporation of [(14)C]amino acids into proteins of virus-infected CEC. We suggest that the major role of primaquine is inhibition of protein synthesis; this results in changes in: hemadsorption, redistribution of lectin receptors, release of progeny, and virus-induced RNA synthesis.

Agglutination↗

Use of BHK cell culture-adapted Newcastle disease virus for immunization of chicks.

Newcastle disease virus mesogenic (Komarov) strain adapted to BHK21 suspension culture was used as a vaccine. The tissue culture-adapted virus was found to be potent and safe when administered to chicks by the intramuscular route. Potency was assessed by challenge test as well as by serology by haemagglutination inhibition and ELISA tests. The ELISA test appeared to be sensitive, efficacious and correlated well with the challenge test.

Adaptation, Physiological↗

Evolution of pigeon Newcastle disease virus strains.

Twenty-seven Newcastle disease virus isolates obtained during the years 1998 and 1999 from racing pigeons were shown to be antigenically indistinguishable from the pigeon paramyxovirus type 1 (PPMV-1) viruses isolated in the years 1983 and 1984. Partial sequencing of 240 base pairs of the F gene demonstrated at least 94.7% identity at the nucleotide level between isolates from 1983 and 1984, and more recent viruses isolated in 1998 and 1999. Most of the nucleotide changes observed were silent mutations as only six amino acid changes were observed. Three amino acid substitutions were observed in the F2/F1 cleavage site. The sequence of the F2/F1 cleavage site of all isolates was typical for pathogenic paramyxovirus 1 viruses. Amino acids at the F2/F1 cleavage site changed from (112)GRQKRF(117) to (112)RRQKRF(117), (112)RRKKRF(117) or (112)RRRKRF(117). The motif (112)RRQKRF(117) was present in the majority of the isolates but the intracerebral pathogenicity indexes of PPMV-1 isolates having this motif was highly variable but largely lower (mean, 0.69) than that reported for PPMV-1 viruses isolated in the years 1983 and 1984 (mean, 1.44).

Amino Acid Sequence↗

Newcastle disease virus infection of L cells.

Newcastle disease virus (NDV) California strain reportedly grows poorly in L cells but replicates very well in chicken embryo cells. NDV-infected L cell cultures show a characteristic virus growth curve with respect to uridine incorporation, but plaque assays of the virus produced 24 h postinfection (PI) show no infectious particles when assayed on L cell monolayers and only a very low titer on chick cell monolayers. Plasma membranes isolated and purified from infected L cells 8 h PI contain all of the major virion proteins. In addition, NDV-infected L cells show a 50% loss of H-2 antigenic activity, a phenomenon previously observed in cells productively infected with vesicular stomatitis virus. These results suggest that at least part of the normal process of NDV maturation occurs in NDV-infected L cells. Sodium dodecyl sulfate-polyacrylamide gel patterns of supernatant virus purified from cells radiolabeled with amino acids from 3 to 24 h PI in the presence of actinomycin D show that all the major NDV structural proteins are present. Electron micrographs of NDV-infected L cells show extensive virus maturation at cell membranes. It can be concluded that infection of L cells with NDV results in a normal production of virus-specific RNA, synthesis of all the major structural proteins, association of the viral envelope proteins with the L cell plasma membrane, and the loss of cell surface H-2 antigenic activity. However, most of the virus particles produced are noninfectious.

Animals↗

Adequacy of commercial lentogenic vaccines against Canadian strains of viscerotropic Newcastle disease virus.

Three field strains of Newcastle Disease virus, designated S20, S21 and S23, isolated from chickens or turkeys in Ontario during the 1971-72 epizootic, were characterized as velogenic viscerotropic viruses. No significant antigenic differences were demonstrated among B1, LaSota and a field strain (S23) of velogenic vescerotropic virus by haemagglutination inhibition or protection tests. Primary water vaccination of chicks with commercial B1 and LaSota vaccines at five weeks of age and aerosol revaccination with the same strains four weeks later resulted in protection that lasted 16 weeks after revaccination against experimental challenge with strain S23. The differences in haemagglutination inhibition titres noted when the homologous or the heterologous viruses were used as haemagglutinating antigen were not statistically significant. The rates of decay of virus neutralizing and haemagglutination inhibition antibodies in vaccinated birds showed a divergence indicating the possible duality of antibodies measured in serum neutralization and haemagglutination inhibition tests.

Administration, Oral↗

Beneficial treatment of patients with advanced cancer using a Newcastle disease virus vaccine (MTH-68/H).

Newcastle Disease Virus Vaccine (MTH-68/H) was administered to patients suffering from advanced neoplastic diseases after non-efficient tumor-destructive treatment. Case reports of selected patients suggest promising effects of this treatment. A prospectively-randomized clinical study (phase III; in accordance with Good Clinical Practice, GCP) was proposed to confirm these results and is currently under consideration.

Adult↗

Velogenic Newcastle disease virus in captive wild birds.

Newcastle disease virus (NDV) was isolated from the faeces of seven different species of clinically healthy captive wild birds. All seven NDV isolates were characterized as velogenic based on the mean death time in embryonated hens' eggs and the intracerebral pathogenicity index in day-old chicks. Three of the isolates were placed in group C1 based on the reactions with monoclonal antibodies. The role of captive wild birds in the epidemiology of Newcastle disease is briefly discussed.

Animals↗

Generation of recombinant lentogenic Newcastle disease virus from cDNA.

Recombinant lentogenic Newcastle disease virus (NDV) of the vaccine strain Clone-30 was reproducibly generated after simultaneous expression of antigenome-sense NDV RNA and NDV nucleoprotein, phosphoprotein and RNA-dependent RNA polymerase from plasmids transfected into cells stably expressing T7 RNA polymerase. For this purpose, the genome of Clone-30, comprising 15186 nt, was cloned and sequenced prior to assembly into a full-length cDNA clone under control of a T7 RNA polymerase promoter. Recombinant virus was amplified by inoculation of transfection supernatant into the allantoic cavity of embryonated specific-pathogen-free (SPF) chicken eggs. Two marker restriction sites comprising a total of five nucleotide changes artificially introduced into noncoding regions were present in the progeny virus. The recombinant NDV was indistinguishable from the parental wild-type virus with respect to its growth characteristics in cell culture and in embryonated eggs. Moreover, an intracerebral pathogenicity index of 0.29 was obtained for both viruses as determined by intracerebral inoculation of day-old SPF chickens, proving that the recombinant NDV is a faithful copy of the parental vaccine strain of NDV.

Amino Acid Sequence↗

Nucleotide sequence of the envelope protein genes of a highly virulent, neurotropic strain of Newcastle disease virus.

The envelope glycoproteins of Newcastle disease virus (NDV), hemagglutinin-neuraminidase (HN) and fusion (F) proteins, play important roles in determining the host immune response and the virulence of that particular virus strain. The complete nucleotide sequence of the HN and F genes of a highly neurovirulent strain of NDV (Texas G. B., 1948) was determined in an effort to study the molecular basis of this strain's neurotropic properties. Comparison of the predicted amino acid sequences for the HN and F among the American NDV strains revealed that the Texas G. B. and Beaudette C envelope genes are closely related to each other and are less closely related to the avirulent B1 Hitchner strain. We have found 11 amino acid changes in the predicted HN protein between the Beaudette C and Texas G. B. strain but only 2 conservative amino acid changes (amino acids 11 and 197) in the F protein between these two strains. Although the virulence of NDV strains has been related to sequences at the cleavage site of F0, the property of neurovirulence cannot depend solely upon these sequences because there are no sequence differences between the Beaudette C and Texas G. B. strains. We suggest that the neurovirulence phenotype could be due to the molecular properties of the HN protein; however, we cannot exclude the possibility that the two conservative amino acid differences between the two F proteins could also play a role in determining the phenotypic differences between these two virus strains.

Amino Acid Sequence↗

Antigenic differences between strains of Newcastle disease virus.

Comparison of strains of Newcastle disease virus by kinetic neutralization tests and immunodiffusion tests (after virion disruption by ether and Tween 80) enabled antigenic differences to be demonstrated between four out of five strains tested. No correlation was demonstrated between the antigenic structure and virulence of these strains.

Antigens, Viral↗

Nucleotide sequence and vaccinia expression of the nucleoprotein of a highly virulent, neurotropic strain of Newcastle disease virus.

The nucleoprotein (NP) of Newcastle disease virus (NDV) was selected to study the relative importance of an internal structural protein in the avian immune response. The NP gene of the virulent, neurotropic NDV Texas GB (TGB) strain was cloned and sequenced. Nucleotide sequence data for the NP gene allowed comparison of the deduced amino acid sequences for the NP genes of NDV-TGB and the avirulent duck isolate NDV-D26. These comparisons demonstrated an 89% nucleotide sequence homology and a 97% homology between the deduced amino acid sequences. The NDV-TGB NP expressed in recombinant vaccinia virus (rVAC) was electrophoretically and immunologically identical to the wild-type NDV-TGB. Although inoculation of chickens with the recombinant vaccinia virus expressing the NDV NP gene elicited anti-NDV antibodies in higher titers than in birds inoculated with live LaSota NDV, this strong anti-NDV response did not protect against lethal challenge with NDV-TGB.

Amino Acid Sequence↗

Studies on the pathogenicity of Newcastle disease virus isolates in guinea fowl.

Newcastle disease viruses isolated from chickens and guinea fowl were characterized as viscerotropic, velogenic strains on the basis of their mean death time, intracerebral pathogenicity index, intravenous pathogenicity index and cloacal and conjunctival mean death time. The pathogenesis of the disease caused by both the strains was studied in 4-week-old guinea fowl. Both strains had an incubation period of 5 days and the birds showed dullness, depression, anorexia, diarrhoea and paralysis of the legs. They also exhibited nervous signs such as incoordination, muscle tremors and trembling of the neck at the advanced stage of the disease. Mortality reached 52% in the group infected with the chicken isolate but it was only 8% in the birds infected with the guinea fowl isolate. No specific changes were observed at post-mortem examination except haemorrhages at the tip of the glands of the proventriculus and in the caecal tonsil. Changes in the lymphoid organs and brain were always present in both the groups. Despite the low mortality, the guinea fowl isolated had multiplied in various organs in the birds. In both groups, the frequency of virus isolation increased from 5 to 10 days post infection.

Animals↗

Experimental infection of vaccinated slaughter ostriches in a natural, open-air feedlot facility with virulent Newcastle disease virus.

The presence of virulent Newcastle disease virus (NDV) since the 1993-94 epidemic in southern Africa holds major implications for the export of ostrich products from this region. A challenge experiment with this field strain was conducted in open-air feedlot facilities under strict biosecurity measures. The experiment was designed to follow vaccination and preslaughter quarantine regulations currently enforced in South African export ostrich facilities in order to determine the viremia period and immune response under these specific circumstances. One hundred forty-three slaughter ostriches were allocated into three test groups, according to the time period between pretrial vaccination and challenge (1-2 mo, 2-4 mo, 4-6 mo), and an unchallenged control group. All birds in the test groups were challenged by oral, tracheal, and ocular routes with a field isolate of NDV. They were slaughtered over the next 4 wk on nine separate occasions and bled on 12 occasions. Virus isolation was attempted from seven sets of pooled samples from each bird to determine the viremia period and the serum antibody concentrations were measured by hemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA) methods to establish an immune response curve. NDV could be back-isolated only up to day 9 postinfection and from only six ostriches with poor immune response titers and corresponding to a rise in antibody levels above an indirect ELISA optical density reading of 0.33. Virus could be recovered only from brain and respiratory tract tissue. The HI test was less sensitive than the ELISA. Immune response curves did not differ significantly between the groups and peaked on day 14 post-infection. From these data, ELISA titers would appear to be a good indicator of the probability that an ostrich will be clinically infected after velogenic NDV challenge. These results also suggest that the current vaccination schedule enforced by the South African Veterinary Authorities results in protective immunity in up to 95% of slaughter ostriches from export approved facilities. The standard 30-day preslaughter quarantine period introduced as part of Crimean-Congo hemorrhagic fever virus control measures also appears sufficient to encompass the determined NDV viremia period of 9-11 days in slaughter ostriches.

Abattoirs↗

Characterisation of Newcastle disease viruses isolated in India.

Eleven Newcastle disease virus (NDV) isolates obtained from outbreaks of disease in chickens (9) and Japanese quail (2) in Tamil Nadu, India were characterised in pathogenicity tests, antigenically, using mouse monoclonal antibodies (MAbs), and other established tests devised to distinguish between different strains. All 11 isolates were shown to be highly virulent for chickens. In indirect immunoperoxidase tests used to assess the ability of a panel of 28 MAbs to bind to infected cell cultures, 10 of the isolates showed an identical reaction pattern, the other isolate (No. 4) failed to react with one MAb which bound to cells infected with the other isolates. Isolates 9 was unstable at pH 3 while the other 10 were stable. All other properties were shared by the 11 isolates.

Animals↗

[Variability and the virulence of the Newcastle disease virus].

Six isolates of the Newcastle Disease virus (NDV), taken at different periods of time after provocation of immune birds with velogenous viscerotrophic strain, are used. It is shown that the virulence of the initial NDV challenge strain remains unchanges up the 46th day of persistence. The isolate, taken after 70 days of carriage, manifests a considerably decreased virulence. It is established that the reduced virulence is not genetically stable and reverts towards the initial one following passage through appropriate host organism. The latent infection with NDV is examined from ecological and practical aspects.

Animals↗

Apoptosis in chicken embryo fibroblasts caused by Newcastle disease virus.

The GB strain of Newcastle disease virus (NDV) was used to infect chicken embryo fibroblasts (CEF). At various times after infection, CEF were harvested and processed for DNA extraction, flow cytometry and electron microscopy. Agarose gel electrophoresis of the DNA at 12 h after infection, showed a laddering pattern, indicating fragmentation of cellular DNA. Flow cytometry analysis of the infected cells showed an increase in the population of smaller cells (apoptotic cells). Electron microscopic examination showed extensive cellular necrosis, but also showed some other cells with condensed chromatin and with extensive perinuclear fragmentation of chromatin; apoptotic bodies could also be readily seen. These data suggest that NDV infection of CEF causes apoptosis, in addition to necrosis.

Animals↗

Clinical and immunological effects of Newcastle disease virus vaccine on bovine papillomatosis.

Newcastle disease virus (NDV) has antineoplastic and immunostimulatory properties, and it is currently being clinically tested in anticancer therapy. In order to analyze the immunostimulatory effects of NDV on bovine papillomatosis, we inoculated 14 cows subcutaneously with an attenuated vaccine containing the LaSota strain of NDV (LS-NDV). Four cows with papillomatosis served as controls. Serum samples were collected from each animal 1 h before and, 7 and 21 days after inoculation. In inoculated cows, on days 7 and 21 the mean antibody titers were log2 2.43 +/- 0.92 and log2 5.57 +/- 0.72 by haemagglutination inhibition (HI), and the mean levels of tumor necrosis factor-alpha (TNF-alpha) were 5.80 +/- 4.19 and 5.39 +/- 2.66 ng/ml by WEHI-164 cytotoxicity assay. Significant differences between inoculated and control animals were evident for antibody titers on day 21 and clinical scores on day 60. A correlation was evident between the TNF-alpha activities and clinical scores on day 21. The clinical observations at day 60 showed that the papillomas in five cows were completely resolved (36%), one animal had no alterations on clinical appearance of the tumor (7%), and papillomas in eight cows were regressed (57%). In conclusion, these results demonstrated that inoculation of LS-NDV vaccine stimulates an antibody response and limited increase in TNF-alpha activity and may enhance clinical recovery in bovine papillomatosis.

Adjuvants, Immunologic↗