Showing papers on "Newcastle disease published in 1972"

Hemolytic interaction of Newcastle disease virus and chicken erythrocytes. II. Determining factors.

Abstract: Standard procedures have been described for measuring paramyxovirus-induced hemolysis. The choice of these procedures is based on the analysis of the behavior of eight different strains of Newcastle disease virus. Significant strain-specific differences in hemolytic activity have been found. The presence of at least two kinds of inhibitors of hemolysis in virus preparations necessitates the use of purified virus when comparisons of hemolytic activities are to be made. In addition, it has been stressed that both hemagglutination titers and hemolysis determinations provide only relative values. Thus, quantitative comparisons can be made only with results obtained on the same day and with the same erythrocyte preparation.

Factors Involved in the Production of Interferon by Inactivated Newcastle Disease Virus

Abstract: Summary Although infective Newcastle disease virus (NDV) did not produce interferon in chick cells, brief heat treatment converted it to an inducer. Experiments in which mixtures of heated and unheated virus were used to induce interferon showed that a substance was produced in infected cells that inhibited interferon formation. Heat treatment of NDV caused the same rate of loss of infectivity and of virus particle RNA polymerase activity, and it was concluded that polymerase activity was essential for virus infectivity. It was also shown that some polymerase activity still existed in heat-inactivated virus able to induce interferon. Appropriate inactivation of the virus by u.v. irradiation or by treatment with β-propiolactone or at pH 2.5, also made the virus into an inducer of interferon, and in each case some virus polymerase activity was present in the inactivated particles. Both u.v. irradiation and β-propiolactone inactivated infectivity more rapidly than polymerase activity, while pH 2.5 treatment had the reverse effect.

Production of interferon by ultraviolet radiation inactivated Newcastle disease virus.

Abstract: MYXOVIRUSES, irradiated with ultraviolet light, are good inducers of interferon formation in both chick and L cells1–4. Unirradiated virus does not induce interferon formation in chick cells1–3, but does so in mouse L cells4, and, in both systems, inducing capacity is lost on prolonged irradiation. Three questions therefore may be asked: (1) why do infective Newcastle disease virus (NDV) and influenza virus fail to provoke interferon formation in chick cells; (2) by what mechanism does irradiated, non-infective, virus produce interferon; and (3) why is this capacity lost on prolonged irradiation?

Studies on the cytopathic effects of Newcastle disease virus: cell surface changes.

Abstract: Summary Infection of chick embryo and baby hamster kidney cells with the virulent Newcastle disease virus (NDV) strains herts, texas and warwick and the mesogenic strain beaudette c produced a significant reduction in the thickness of the cell coat material. There was a temporal relationship between the reduction in coat thickness, the formation of polykaryocytes by cell fusion, and the release of lysosomal enzymes in cells infected with these strains. No reduction in coat thickness was found in cells infected with the avirulent strains, queensland and ulster, which did not produce cell fusion. Little lysosomal enzyme release was found in cells infected with these strains. Cell fusion and the reduction in coat thickness in cells infected with the virulent strains were inhibited by treatment of infected cells with anti-NDV serum without impairment of virus replication.

Secretory Newcastle Disease Virus Antibodies from Chicken Respiratory Tract

Abstract: The nature of the antibodies extracted from lungs of chickens immunized intranasally by Newcastle disease virus (NDV) was analyzed by chromatography on Sephadex G-200, DEAE cellulose, as well as by electrophoresis on acrylamide gel. Specific local antibody activity was always located at the same region as serum antibodies with a molecular weight of 160,000 to 180,000. By immunodiffusion and immunoelectrophoresis this antibody was shown to be antigenically identical to humoral IgG serum antibodies. Concentrations of hexosamine were 1.55% for serum and 1.35% for lung antibodies. The S values as determined by analytical ultracentrifugation were 6.9 and 7.1 for local and humoral antibodies, respectively. It was concluded, therefore, that local anti-NDV antibodies belong to the IgG type of immunoglobulin, and that this immunoglobulin is responsible for the systemic as well as for the local immunity in the chickens.

Infectious coryza infectious bronchitis and newcastle disease vaccines and production thereof

Abstract: A killed combined vaccine comprising killed Hemophilus gallinarum, killed infectious bronchitis virus and killed Newcastle disease virus: the said combined vaccine being prepared by mixing, in such proportions that the said vaccine contains effective amounts of each killed agent; killed Hemophilus gallinarum, the bacteria being grown in a natural medium then killed; killed infectious bronchitis virus; and killed Newcastle disease virus, the latter two being prepared by a conventional process using embryonated chicken eggs. The killed combined vaccine is useful for the immunization of poultry against respiratory infections caused by Hemophilus gallinarum, infectious bronchitis virus, and/or Newcastle disease virus.

Stability and precursor relationships of virus RNA.

Abstract: Summary Pulse-chase experiments with [3H]-uridine were performed with glucosamine-treated chick cells infected by RNA viruses. It was established that in cells infected by fowl plague virus both virus RNA and the RNA with the complementary base sequence were metabolically stable. Newcastle disease virus-specific RNA was also metabolically stable in chick fibroblasts. In cells infected by Semliki Forest virus, radioactivity was not lost from the virus-induced 26 S RNA, while the activity of the partially RNase-resistant 20 S RNA could be chased to RNase-sensitive RNA of high mol. wt.

Effect of exogenous interferon on L cells persistently infected with Newcastle disease virus.

Abstract: Prolonged treatment with relatively high concentrations of interferon was required to “cure” L cells persistently infected with Newcastle disease virus.

Growth of Newcastle Disease Virus and Rubella Virus in Rheumatoid and Nonrheumatoid Synovial Cell Cultures

Abstract: 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.

The effect of infection with different strains of Newcastle disease virus on cellular RNA and protein synthesis.

Abstract: A large number of Newcastle Disease virus (NDV) strains have been isolated which differ markedly in their virulence for chickens (Waterson, Pennington & Allan, 1967), and which have been classified as velogenic (the most virulent), mesogenic (of intermediate virulence) and lentogenic (the least virulent). Investigation of the virus multiplication cycle in vitro has shown that a correlation exists between virulence and the ability to cause a cytopathic effect and form plaques in chick embryo cells (Schloer & Hanson, 1968; Reeve & Alexander, 1970); and recently Reeve & Poste (1971) have demonstrated a correlation between virulence and the ability to cause polykaryocytosis. It has also been suggested that a correlation exists between virulence and the ability to inhibit cellular protein synthesis (Reeve et al. 1971). We have examined the effect of infection with 13 strains of NDV on cellular RNA and protein synthesis, and have found several exceptions to the correlation observed by Reeve et al. (1971).

Viral Ribonucleic Acid Synthesis by Newcastle Disease Virus Mutants Isolated from Persistently Infected L Cells: Effect of Interferon

Abstract: The synthesis of different viral ribonucleic acid (RNA) species was studied in chick embryo (CE) and mouse L-cell cultures infected with the Herts strain of Newcastle disease virus (NDV(o)) and a mutant isolated from persistently infected L cells (NDV(pi)). In CE cell cultures, both viruses synthesized significant amounts of 54, 36, and 18S RNA. However, in L cells, synthesis of 54S virion RNA was markedly reduced. From these results, it seems likely that the low yield of infective virus in L cells is due to a deficient synthesis of 54S RNA in this host. On this basis, however, it is apparent that the "covert" replication of NDV(o) in L cells is due to factors other than viral RNA synthesis. When low concentrations of interferon were used to pretreat CE cells, a differential effect on the synthesis of various RNA species was observed. The 18S RNA of NDV(o) was more sensitive to interferon action than the 36 and the 54S RNA species. In contrast, the 18S RNA of NDV(pi) was less sensitive than the 36S and the 54S RNA. The inhibition of 54S RNA synthesis correlated with the reduction of viral yield and explained the greater sensitivity of NDV(pi) to interferon.

Newcastle disease in Paraguay.

Abstract: A serious outbreak of a velogenic strain of Newcastle disease occurred in Paraguay in August, 1970. Deaths of domestic poultry were very high in affected flocks. Vaccination against Newcastle disease had been prevented by law. This was rescinded, however, and voluntary vaccination was started. The incidence of new outbreaks dropped sharply thereafter. This is the first report of isolation and identification of Newcastle disease in Paraguay. Evidence is presented, however, suggesting that Newcastle was present in Paraguay between 1957 and 1959. At that time, diagnostic facilities were not available, so no attempt was made to differentiate between Newcastle disease and fowl plague by those doing the diagnostic and regulatory work.

Comparative Cytopathology of Newcastle Disease Virus: Use of Ferritin-Labeled Antibody on Allantoic and Intestinal Epithelium

Abstract: Abs/ruc/. Cytopathology and virion structure were compared in tissues of chicken chorioallantois and intestine infected with four Newcastle-disease-virus (NDV) strains of differing virulence and tissue tropism. Virions of the recently isolated enterotropic Ulster and viscerotropic 219 strains did not differ structurally from established NDV strains B1 and GB. A ferritin-labeled anti-NDV globulin combined with virions of all strains. In chorioallantoic membranes, the BI and Ulster strains replicated by budding from surface allantoic epithelial cells. The GB and 219 strains replicated throughout the membrane and produced extensive necrosis; they also had a greater tendency to replicate in and damage vascular tissues. Lesions in intestine were not seen by histologic, immunofluorescent, or ultrastructural examination in control and BI infections. The Ulster strain replicated in epithelium of the anterior intestine; viral antigens were present chiefly in the duodenum. In contrast, GB and 219 strains replicated in the submucosa of the posterior gut and induced severe enteritis with lymphoid necrosis, vasculitis, histiocytosis, and hemorrhage. Naturally occurring Newcastle disease virus (NDV) infection of the chicken intestine includes a spectrum of conditions varying from subclinical infection (without enteritis) [4, 1 I, 121 to peracute fatal disease with diarrhea, severe enteritis, and necrosis [7]. Although these differences may be influenced by host factors such as age, body temperature, and adrenocortical activity, they reflect basic differences in the virulence of different NDV strains [lo]. The virulence of these strains for chickens and chicken embryos is allegedly directly related to their capacity to destroy cells and cause polykaryocytosis by cell fusion in vitro [I, 14, 161. Virulent strains produce marked cytopathic changes in intestinal tissue with high titers of virus. Avirulent strains, in contrast, do not produce destructive cytopathic changes despite relatively high titers of virus [3].

Relations in interferon production and other known properties between CAL 11914 and TCND strains of Newcastle disease virus.

Abstract: Strain Cal 11914 of Newcastle disease virus (NDV) produced interferon (IF) in cultures of chick embryo fibroblast (CEF) as well as in chickens. The TCND strain of NDV did not produce IF in either system. IF titers reached a peak 4 hours after inoculation of CEF cultures, and IF was still detectable 18 hours later. In the chicken, IF titers reached a peak 2 hours after intravenous inoculation, and IF was still present 24 hours later, the longest period tested. The question was discussed of whether a strain of NDV used in a vaccine should be capable of producing IF.

Isoelectric behaviour of different rabbit interferons induced by Newcastle disease virus.

Abstract: The isoelectric behaviour of the NDV-induced rabbit serum interferon was compared with different NDV-induced interferons from rabbit cells. The activity of serum interferon was found in a pH range from 4.6—6.2. In contrast, the isoelectric positions of cell interferons could be demonstrated in a more acid pH range between pH 3.7 and 5.0.

Inhibition of Bactericidal Capacity in Mice after Administration of Newcastle Disease Virus

Abstract: Administration of live Newcastle disease virus to mice was followed by an enhancement of the infections caused by the injection of gram-negative bacteria Similar findings were obtained with the use of other viruses The evolution of the viable bacterial populations in the blood and the spleen suggested that an alteration in the phagocytic capacity of tissue macrophages was not responsible for this phenomenon Impairment of the post-phagocytosis bactericidy, linked to the presence of live virus, is a likely explanation of the observed enhancement of the bacterial infection

Production of hemadsorption-negative areas by sera containing Australia antigen.

Abstract: In 1965, in collaboration with Marcus, we described an assay system for rubella virus growing under noncytopathic conditions. 1 Green monkey kidney cells infected with rubella virus were challenged with a high multiplicity of Newcastle disease virus (NDV) five days later and did not replicate the Newcastle disease virus. The replication of NDV was measured by a standard hemadsorption test with bovine erythrocytes. The rubella infected cells stood out as hemadsorption negative, since they did not produce hemagglutinin. This noninterferon-mediated interference against superinfection with NDV has been called intrinsic interference. 2 Subsequently, Sindbis and West Nile viruses, 2 polioviruses, 2 lymphocytic choriomeningitis virus, 3 infectious bronchitis virus, 4 cytomegalovirus, 5 and reovirus 6 have also been shown to induce intrinsic interference when growing under noncytopathic conditions in a variety of tissue culture systems. We sought interference with the development of NDV hemadsorption as an assay system for serum hepatitis

Complement-fixation test for detection of viral antibodies in chicken serum. I. Standardization of the test for detection of antibodies to Newcastle disease virus and polyoma virus.

Abstract: A modified direct complement-fixation (CF) test is described for the detection of serum CF antibodies to Newcastle disease virus (NDV) and polyoma virus in chickens made hyperimmune to these viruses. Fixation of the guinea pig complement (gpc') by the virus antigen-chicken antibody required the addition of an optimal dilution of unheated normal chicken serum (NCS) to the gpc' at the time of its addition to the test. Partially purified antigens were required for the test and the technique for their preparation is described. The NCS could be stored at -70 C for 12 months without any detectable decrease in activity but at 4 C had a partial loss of its titer-enhancing ability within 24 hours but no further loss in the next 48 hours.