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 163 records · Page 9Linked to original sources

Relationship of plaque size and virulence for chickens of 14 representative Newcastle disease virus strains.

Ability of 14 Newcastle disease virus strains to produce large plaques was related to virulence for chickens. Plaque-size comparisons were made under standard conditions in chick embryo cell monolayers. All plaque-producing strains showed a range of plaque sizes modified to a degree by the overlay medium used. An increase in size was found for most strains under methyl-cellulose overlay medium. Markedly larger plaques were found under this medium for both Calif-RO and Calif-CG strains. Heterogeneity in plaque size was most pronounced in velogenic (high virulence) strains. Only populations of small plaques were found in mesogenic (intermediate virulence) strains, and plaques were rarely found in lentogenic (low virulence) strains. Statistical analysis showed that the plaque size of velogenic strains differed significantly from mesogenic strains. None of the 11 plaque-producing strains had a normal distribution of plaque sizes, owing primarily to the presence of different genotypes within the plaquing population of a strain. This was demonstrated by derivation of clones from two of the strains. The populations of the large (Herts L) and small (Herts S) clear plaque clones derived from Eng-Herts were homogenous and distinct from one another on the basis of plaque size. Herts L was more virulent than Herts S. Although Herts L became more heterogenous in respect to plaque size upon repeated passage in embryonated eggs, no decrease in virulence of the strain was observed.

Agar↗

Standardization of a duplex RT-PCR for the detection of Influenza A and Newcastle disease viruses in migratory birds.

Influenza A and Newcastle disease viruses are pathogens of social and economical importance known to be disseminated throughout the world by migratory birds. Many efforts have been made to control the introduction of these viruses into new environments, and complete world surveillance has yet to be achieved. Virus isolation and immunofluorescence techniques are time consuming, have inherent limited sensitivity and present a lack of host cells permissive universally to all Influenza A viruses. In this paper, the use of a duplex RT-PCR is described capable of sorting out any NDV and Influenza A virus strain simultaneously in oral and cloacal swab specimens. This method includes fluorescent detection of amplicons that provide accurate analysis of many DNA fragments within one base discrimination. Reference viruses were used for standardization of the assay and samples from wild-type viruses were screened, with four positive results for Influenza A detected in migratory birds captured in the state of Sao Paulo. This screening test can be considered a first step for further studies of these viruses circulating in avian species in Brazil, and hopefully will contribute to broaden the sample spectrum from wild birds, leading to a better understanding of these viruses and their participation in the southeastern region of the country.

Animals↗

Recent isolates of Newcastle disease virus in Australia.

Forty-five recently isolated strains of Newcastle disease virus and the V4 vaccine strain of Newcastle disease virus were used to infect experimental chickens. Neither V4 nor any of the new strains produced detectable clinical disease. All the viruses produced an antibody response and spread by contact. Some of the newly isolated viruses produced a more rapid serological response than V4 virus did. Dual or multiple infections with one of the new strains of Newcastle disease virus, infectious bronchitis virus and Escherichia coli did not enhance the pathogenicity of any of the agents.

Animals↗

Different pools of free myoinositol in chick-embryo cells as indicated by infection with Newcastle-disease virus.

Infection of chicken fibroblasts with Newcastle-disease virus indicates that cellular inositol is compartmented in at least two pools. Only the smaller pool is directly connected with the biosynthesis of phosphatidylinositol. Entrance of exogenous inositol into this pool is inhibited by phlorizin but not by the virus. Three hours after infection Newcastle-disease virus blocks the entrance of inositol from the small pool into one (or more) subsequent larger pool(s). About five hours after infection the virus enhances the catabolism of phosphatidylinositol in chicken cells and about seven hours after infection the permeability of the plasma membrane increases.

Animals↗

[A recombinant fowlpox virus expressing the fusion protein of Newcastle disease virus strain F48E8 and its protective efficacy].

The transfer vector pFGF1175-1 was constructed by insertion the fusion protein gene of Newcastle disease virus (NDV) F48E8 strain into the insertion vector pFG1175-1, downstream of P7.5 promotor, and then transfected chicken embryo fibroblast (CEF) cell cultures which had been infected with fowlpox virus (FPV) Chinese vaccine strain 282E4 for 3-4 hours. Recombinant FPV with blue plaques were selected and purified in CEF cell culture laid agar containing X-gal. The recombinant FPV named rFPV-NDF was confirmed expressing NDV fusion protein by indirect immunofluorescence assay, and could protect chickens against virulent NDV challenge, The protective rate was 96.7%.

Animals↗

The immune response of the chick following viral vaccinations and immunization with sheep red blood cells.

The effects of viral vaccinations and immunization with sheep red blood cells (SRBC) on the humoral response of pullets were investigated. Pullets were vaccinated with Marek's disease virus, Newcastle disease virus (NDV), infectious bronchitis virus (IBV), and infectious bursal disease virus at appropriate ages used in commercial practice. At seven weeks, the pullets were intramuscularly immunized with SRBC. NDV and IBV antibodies were detected by hemagglutination-inhibition tests. Hemagglutination (HA) titers were established against SRBC. IBV antibody titers were not affected by vaccination or by immunization with SRBC. NDV antibody titers were significantly increased by vaccination and by immunization with SRBC. The SRBC agglutinin response was also positively affected by vaccination. The HA titer increase consisted of a rise in 2-mercaptoethanol (2-ME)-sensitive antibodies and a fall in 2-ME-resistant antibodies.

Animals↗

[Synthesis of virus-specific RNA under conditions of homologous and heterologous interference by Newcastle disease virus].

Homologous and heterologous interference by Newcastle disease virus (NDV) was manifested in a marked inhibition of virus-specific RNA synthesis of both the interacting viruses. Inactivation of the interfering NDV by irradiation reduced its capacity to inhibit the synthesis of virus-specific RNA of the homologous virus, leaving its effect on the synthesis of RNA of the heterologous virus unchanged. In contrast, treatment of cell cultures with heparin leading to reduced interferon production eliminated the heterologous interference but did not affect the homologous interference.

Animals↗

Growth of Newcastle disease virus and rubella virus in rheumatoid and nonrehumatoid synovial cell cultures.

Rheumatoid and nonrheumatoid synovial cell cultures were challenged with Newcastle disease virus and rubella virus in an attempt to confirm reports that rheumatoid synovial cells are relatively resistant to infection with these viruses. Newcastle disease virus caused complete cell destruction by day 7 in both rheumatoid and nonrheumatoid cultures, and peak virus titers were similar. Rubella virus replicated in both rheumatoid and nonrheumatoid synovial cell cultures, and no consistent differences in virus titers were detected. Rubella-infected cell lines were observed for up to 28 days and no virus-specific cytopathic effect was seen.

Adolescent↗

[Characteristics of 24S and 35S virus-specific RNA in cells infected with Newcastle disease virus].

The properties of 24S and 35S virus-specific RNAs of Newcastle disease virus were studied after denaturation. It was shown that 60-80% of 24S and 35SRNA consisted of agglomerates of molecules of virus-specific 18S RNA. Undissociable upon denaturation, 24S RNA contained mainly the same components as undenaturated RNA and consisted completely of sequences of virus-specifis 18S RNA. Undissociable 35S RNA contained no "heavy" heterogenous material present in the intact undenaturated RNA and 75% of it consisted os sequences of 18S virus-specific RNA. Some sequences present in undissociable 24S RNA were absent in undissociable 35S RNA. The aggregation of virus-specific na-transcripts and subsequent formation of covalent bonds between transcripts as well as possible formation of "solid" transcripts of the adjacent genes are discussed.

Newcastle disease virus↗

Restitution of hemagglutinating activity to spikeless particles of HVJ (Sendai virus) by glycoprotein components of Newcastle disease virus.

Spikeless particles of HVJ (Sendai virus) lacking in hemagglutinating (HA) activity were obtained by enzymatic digestion of virions with trypsin followed by centrifugation through a sucrose gradient. When they were mixed with glycoprotein components of Newcastle disease virus (NDV) obtained by treatment of purified virions with deoxycholate (DOC), the mixture showed hemagglutination reaction, which was inhibited by anti-NDV serum, but not by anti-HVJ serum. Sedimentation profile of the HA active agents was then examined by centrifugation of the mixture of spikeless particles of HVJ (labeled with 3H-uridine) and glycoproteins of NDV (labeled with 14C-amino acid mixture). The results showed that the peak of HA activity had both of the radioactivities, and that the sedimentation rate of the HA was faster than that of spikeless HVJ but slower than that of intact HVJ. Electron micrographs of such HA active structures showed that they were morphologically closely similar to intact virion of HVJ, although they had neither hemolytic activity nor infectivity. The mixture of spikeless HVJ and glycoproteins of HVJ or NDV which were removed from virions by proteolytic enzymes, on the other hand, did not show any detectable hemagglutinating activity.

Deoxycholic Acid↗

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 products of 631 and 309 nucleotides, respectively. The multiplex RT-PCR assay, for detecting both viruses simultaneously, was compared with the single-virus RT-PCR assays for its sensitivity and specificity. The specific primers amplified products of predicted size from each virus in the multiplex as well as the single-virus RT-PCR assays. The multiplex RT-PCR assay was determined to be equivalent to the single-virus RT-PCR assays for detecting both NDV and APV-Col. This multiplex RT-PCR assay proved to be a sensitive method for the simultaneous and rapid detection of NDV and APV-Col. This assay has the potential for clinical diagnostic applications.

Animals↗

Acute pancreatitis in chickens due to non-virulent Newcastle disease virus.

A non-virulent Newcastle disease virus (strain APMV-1 96/89 VB) was isolated from a broiler chicken from a backyard flock. Using monoclonal antibodies, the virus was shown to be different from the vaccinal virus strains Hitchner, La Sota and Ulster. The virus was shown to replicate in the pancreas of one-day-old specific pathogen-free chickens infected orally, and the histological lesions observed in the pancreas of chickens inoculated with the fourth chicken passage of the virus five to nine days after infection were consistent with an acute pancreatitis.

Animals↗