Showing papers on "Newcastle disease published in 1969"
TL;DR: The results indicate that a single, partly dominant, autosomal factor is responsible for the difference in circulating interferon production between both parent strains.
Abstract: Circulating interferon production, induced by Newcastle disease virus, is about seven times higher in C57 Black mice than i Balb/c/Gif mice. A Mendelian analysis was carried out and circulating interferon production was measured in reciprocal F1 hybrids, in the F2 generation, in progeny of backcrosses of F1 hybrids to either parent strain, and in second backcross progeny. The results indicate that a single, partly dominant, autosomal factor is responsible for the difference in circulating interferon production between both parent strains.
45 citations
TL;DR: Newcastle disease virus was found to contain three major proteins, which appear to be monomeric and to consist of a single large protein of an approximate molecular weight of 62,000.
Abstract: Newcastle disease virus was found to contain three major proteins. The structure unit of the viral nucleocapsid appears to be monomeric and to consist of a single large protein of an approximate molecular weight of 62,000.
33 citations
TL;DR: Chick embryo cells infected with ultraviolet irradiated NDV synthesize viral RNA though they do not produce infectious virus, and the viral origin of the RNA was demonstrated by annealing experiments using RNA from purified NDV virions.
Abstract: Viral RNA Synthesis in Chicken Cells infected with Ultraviolet Irradiated Newcastle Disease Virus
30 citations
TL;DR: Some properties of eight strains of Newcastle disease virus (cell-fusing ability, hemolysin, heat stability of hemagglutinin or of Hemolysin) do not correlate with virulence of these strains.
Abstract: Some properties of eight strains of Newcastle disease virus (cell-fusing ability, hemolysin, heat stability of hemagglutinin or of hemolysin) do not correlate with virulence of these strains.
29 citations
24 citations
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21 citations
TL;DR: In chick fibroblast cell cultures infected with Newcastle disease virus an RNA-dependent RNA nucleotidyl transferase (RNA polymerase) has been detected which was not found in non-infected cells.
Abstract: Summary
In chick fibroblast cell cultures infected with Newcastle disease virus an RNA-dependent RNA nucleotidyl transferase (RNA polymerase) has been detected which was not found in non-infected cells. The enzyme mainly synthesizes RNA complementary to viral RNA as shown by nearest neighbour analysis and hybridization experiments. In contrast to the influenza virus-induced enzyme the Newcastle disease virus enzyme cannot be inhibited by dextran sulphate. Its synthesis is not inhibited by actinomycin. It is first detectable 3 hr after infection and it has reached its highest activity at 5 hr after infection.
16 citations
TL;DR: The egg-bit technique was modified and adapted for measuring Newcastle disease virus (NDV) and its antibodies and results from egg bits were compatible with results from conventional techniques.
Abstract: SUMMARY The egg-bit technique was modified and adapted for measuring Newcastle disease virus (NDV) and its antibodies. Infectivity of 3 strains of NDV generally increased with the incubation period. Infectivity titers did not differ greatly with bits from embryos either 10, 11, or 12 days old. Virus-neutralization tests with NDV were accomplished successfully with egg bits. Results from egg bits were compatible with results from conventional techniques. Data are presented demonstrating the role of HI antibodies in the egg-bit neutralization test.
15 citations
TL;DR: Immuno-globulin chemically extracted from the yolk of eggs laid by hens recovered from Newcastle Disease possessed specific haemagglutination inhibiting antibody and was as effective as the raw yolk in conferring passive protection, but for a shorter period of time.
12 citations
TL;DR: The porcine kidney cell line PK-2a has been widely used for studies on Japanese B encephalitis virus, which has a consistently severe cytopathic effect on the cells, and an avirulent strain of the virus was detected as a contaminant in normal uninoculated cells.
Abstract: The porcine kidney cell line PK-2a has been widely used for studies on Japanese B encephalitis virus, which has a consistently severe cytopathic effect on the cells (Inoue & Ogura, 1962). Whilst attempting to attenuate swine fever virus using this cell line, an avirulent strain of the virus was detected as a contaminant in normal uninoculated cells because it interfered with titration of swine fever virus by the END (exaltation of Newcastle disease virus) method. The END method, which was devised and designated by Kumagai et al. (1961), is an in vitro technique for detecting and titrating non-cytopathic swine fever virus. The method is based on an enhancing effect of swine fever virus on Newcastle disease virus in swine-testicle-cell cultures. The present report described the evidence for the existence of the contaminant virus in PK-2a cells.
The porcine kidney cell lines PK-2a were obtained from four laboratories in Japan.
TL;DR: A method suitable for the large-scale extraction and purification of Newcastle disease virus-specific IgG from the yolks of eggs laid by hens newly recovered from Newcastle disease is described.
TL;DR: Experiments were designed to determine whether interferon induced by Newcastle disease virus (NDV) could protect mice from infection by influenza virus transmitted by other mice.
Abstract: There are many reports in the literature indicating that the administration of exogenous interferon or induction of endogenous interferon can protect experimental animals against certain virus infections (reviewed by Finter, 1966, and Vilcek, 1969). In most of these studies, challenge was by parenteral inoculation of relatively large quantities of virus and the protective effects of interferon were assessed in terms of decreased mortality or less severe disease. However, naturally acquired virus infection is generally the consequence of exposure to much smaller quantities of virus, and with respiratory viruses, infection is initiated by deposition of virus in appropriate areas of the respiratory tract and not by parenteral inoculation. Accordingly, experiments were designed to determine whether interferon induced by Newcastle disease virus (NDV) could protect mice from infection by influenza virus transmitted by other mice. This experimental system was described in detail by Schulman & Kilbourne (1963) and was used to study the effects on transmission of infection of other modifications of the host such as immunization (Schulman, 1967).
TL;DR: The INC-method has been shown to be an accurate method for the titration of HCV and neutralizing antibodies and proved to be as sensitive as the swine inoculation test.
Abstract: A titration method for hog cholera viruses (HCV) of low virulence (strain LOM) has been described. The method, designated the INC-method, is based upon interference between the preinoculated strain LOM and the postinoculated Newcastle disease virus in swine testicle cell cultures. The INC-method has been shown to be an accurate method for the titration of HCV and neutralizing antibodies and proved to be as sensitive as the swine inoculation test.
TL;DR: Evidence is presented indicating that virus-induced proteins, which were synthesized by 6 hr after infection, were involved in the RNA degradation process, and this affected the synthesis of both cellular RNA and DNA in chick embryo fibroblast monolayers.
Abstract: Summary
Following Newcastle disease virus infection, the synthesis of both cellular RNA and DNA in chick embryo fibroblast monolayers was inhibited. In such monolayers, Newcastle disease virus infection did not significantly reduce the content of cellular DNA within 10 hr, but did reduce the amount of cellular RNA by about 50% in that time. A part of the RNA was degraded into acid-soluble material and leaked out of the cells. Some fraction of the ribosomal RNA gave rise to small molecular weight fragments which sedimented near the transfer RNA region as determined by sucrose density gradient centrifugation. Evidence is presented indicating that virus-induced proteins, which were synthesized by 6 hr after infection, were involved in the RNA degradation process.
TL;DR: The results indicate that this strain of NDV inefficiently replicates progeny virus and that viral directed protein synthesis (hemagglutinin) is significantly depressed in L cells, substantiate the notion that interferon is not responsible for the abortive nature of viral replication.
Abstract: SummaryThe temporal relationship between virus production and interferon biosynthesis was studied in L cells infected with NDV (Roakin strain). The results indicate that this strain of NDV inefficiently replicates progeny virus and that viral directed protein synthesis (hemagglutinin) is significantly depressed in L cells. These latter findings which are in contradistinction to the observations of others who used the Beaudette and Italien strains of NDV, reflect a primary difference in the characteristics of NDV strains. Evidence is also presented which indicates interferon appears very late in the replication cycle of the virus. These data substantiate the notion that interferon is not responsible for the abortive nature of viral replication.
TL;DR: Young chickens were immunized against Newcastle disease virus (NDV) with killed-virus antigen administered in the drinking water with a potential for early protection at satisfactory levels.
Abstract: SUMMARY Young chickens were immunized against Newcastle disease virus (NDV) with killed-virus antigen administered in the drinking water. Variables studied were age of chickens, concentration of antigen, and interval of antigen application. The antigen used was beta-propiolactone-killed NDV from the chicken embryo allantoic fluids. Challenges were made with 104.5 bird-lethal-dose-50 of homologous virus given intramuscularly. Of groups 1, 7, and 14 days of age given antigen at a 1% concentration continuously for 14 days, only the 14-day-old chickens demonstrated a potential for early protection at satisfactory (80%) levels. In further experiments, these chickens achieved satisfactory protection during the broiler period when given a 5% antigen concentration for the first two days and restimulated every 5 days for six weeks with a 2-day application of 2.5% antigen. Protection was comparable from two antigen applications: a 20% concentration for two days, followed on day 12 with 10% antigen. Specific hemagglutinating-inhibiting and virus-neutralizing antibodies were induced by this method of vaccination. A common mass vaccination method used by the poultry industry against Newcastle disease virus (NDV) is administration of viable lentogenic strains of NDV in the drinking water. This procedure is relatively inexpensive and requires minimal labor and time, important attributes for large-scale use. To be effective, however, live viruses must infect the chicken. Then they may stress and predispose the chicken to other disease agents, simultaneously causing some loss in meat or egg production. The vaccine strains 568
TL;DR: The response obtained in fully susceptible and passively immune chickens using live tissue culture-derived Newcastle Disease vaccines were compared with those obtained using an inactivated vaccine, and a live avirulent virus vaccine was prepared in embryonated eggs.
TL;DR: It is suggested that the relative ineffectiveness of interferon in protecting mice against influenza is due to an intrinsic characteristic of the virus itself rather than the type ofinterferon induced or the route of virus challenge.
Abstract: Various interferon inducers are known to elicit protection against lethal or infecting doses of certain viral agents. Because of the relatively high morbidity rate of influenza and its seasonal occurrence, we wished to determine whether statolon-induced interferon might be effective in controlling this disease. Mice were treated intraperitoneally with statolon and challenged with influenza A(2) virus by the intranasal route. Although interferon was present in the serum at the time of virus administration, no change in mortality rate was observed. There was, however, a significant increase in the mean survival time of treated animals. Similar results were obtained when Newcastle disease virus was used as the interferon inducer. To determine the effect of the route of challenge, other mice were treated with statolon or Newcastle disease virus and inoculated with mengovirus by the intranasal or intraperitoneal route. The results demonstrated that the treated mice were protected to similar degree against challenge by either route. It is suggested that the relative ineffectiveness of interferon in protecting mice against influenza is due to an intrinsic characteristic of the virus itself rather than the type of interferon induced or the route of virus challenge.
TL;DR: Ribonucleic acid synthesis of chick embryo fibroblasts was inhibited by two members of the myxovirus group, Newcastle disease virus (NDV) and fowl plague virus.
Abstract: Ribonucleic acid (RNA) synthesis of chick embryo fibroblasts was inhibited by two members of the myxovirus group, Newcastle disease virus (NDV) and fowl plague virus. It was also found that cellular deoxyribonucleic acid-dependent RNA polymerase was inhibited by a cytoplasmic factor induced by NDV infection.
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TL;DR: A study was made to compare the immune response of chickens to 6 strains of beta-propiolactone-inactivated NDV to determine whether strain virulence could be correlated with antigenicity and to circumvent the difficulties encountered by other investigators.
Abstract: SUMMARY Six strains of beta-propiolactone-inactivated Newcastle disease virus were compared for their immunogenicity in chickens. Texas GB, Kansas-Manhattan, and B1-Hitchner produced significantly higher HI antibody than NJ-LaSota, Mass-MK-107, and California 11914 strains of NDV, with each group performing about the same. Hanson et al. (3), in a comparison of the immunogenicity of five strains of Newcastle disease virus (NDV) as formalized antigens, showed that chickens immunized with Manhattan-Kansas and Roakin-NJ were more resistant to challenge than chickens receiving GB-Texas, RO and B1 strains. Sullivan et al. (4), using beta-propiolactone-killed preparations of three strains of NDV, demonstrated that a single injection of GB-Texas afforded better protection than a single injection of Roakin or Manhattan-Kansas. After a booster injection, however, chickens receiving any of the three strains showed essentially the same resistance to challenge. A study was made to compare the immune response of chickens to 6 strains of beta-propiolactone-inactivated NDV and to determine whether strain virulence could be correlated with antigenicity. To circumvent the difficulties encountered by other investigators, the quantity of antigen in each strain of virus used for vaccination was standardized and the serum from individual birds was tested for antibody. The hemagglutination-inhibition (HI) antibody titers were then compared both within and between strains of NDV to determine their significance.
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TL;DR: There was a sharp decrease both in the amounts of interferon formed in mice in response to an injection of Newcastle disease virus and in their resistance to the toxic effects of influenza virus.
Abstract: Summary
When mice were inoculated intravenously with Newcastle disease virus, interferon was formed, and the mice were protected against the lethal effects of a subsequent intravenous injection of a toxic strain of influenza A virus. Mice were similarly protected when injected intravenously with a suspension of mouse macrophages which had been stimulated to produce interferon by treatment in vitro with Newcastle disease virus. It is known that the reticuloendothelial system has a role in the production of interferon and in the development of non-specific resistance to virus infections. When this system was blocked completely by a thorotrast injection, or partially as the result of splenectomy, there was a sharp decrease both in the amounts of interferon formed in mice in response to an injection of Newcastle disease virus and in their resistance to the toxic effects of influenza virus.
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