• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.277-284
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• 1998

Serum samples were collected from 100 breeders and their progeny 600 broilers. The breeders and broilers were vaccinated against infectious bronchitis(IB), infectious bursal disease(IBD) and Newcastle disease(ND) viruses according to general vaccination program. The antibodies in serum samples against IB, IBD and ND viruses were detected by ELISA using commercial ELISA kit. Geometric mean titer(GMT) of ELISA was monitored from 1-day-old to 35-day-old broilers and compared to that of breeder chickens. The GMT of ELISA to IB, IBD and ND was declined half level of the day old broiler's antibody titers at about 4, 9 and 4 days of age. The GMT of ELISA to IB, IBD and ND was declined than that of protective antibody titer at about 12, 11, and 15 days of age. Thereafter, the GMT of ELISA to IB, ND were declined and disappeared according to age of broilers. The GMT of ELISA to IBD was declined according to age of broilers, but at 25 days of age increased and 31 days of age increased than that of protective antibody titer. Taken together, these studies led to conclusion that time-course of antibody titers of broilers from vaccinated breeders and that of progeny broliers which vaccinated according to vaccine program. Those are very important data to design vaccine program to breeders and broilers.

• Korean Journal of Poultry Science
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• v.4 no.1
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• pp.41-49
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• 1977

최근 축산물의 소비가 증가함에 따라 쇠고기의 품질현상을 빚어 육류의 수입마저 허용케 되었으며 이로 인하여 양계산물의 소비도 늘어나게 되어 양계업도 근래보기 드물게 성업을 이루고 있다. (중략)

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2005.11a
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• pp.75-76
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• 2005

• BMB Reports
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• v.40 no.5
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• pp.611-616
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• 2007

$E^{rns}$ is an envelope glycoprotein of classical swine fever virus (CSFV) and has an unusual feature of RNase activity. In the present study, we demonstrate that $E^{rns}$ counteracts Newcastle disease virus (NDV)-mediated induction of IFN-$\beta$. For this purpose, $E^{rns}$ fused to the enhanced green fluorescent protein (EGFP) was transiently expressed in porcine kidney 15 (PK15) cells. In luciferase activity assay, $E^{rns}$-EGFP was found to prevent IFN-$\beta$ promoter-driven luciferase expression and block the induction of IFN-$\beta$ promoter mediated by NDV in a dose-dependent manner. Through IFN-specific semi-quantitative RT-PCR detection, obvious decrease of IFN-$\beta$ mRNA in NDV-infected PK15 cells was observed in the presence of $E^{rns}$-EGFP. In contrast, EGFP alone showed none of this block capacity. In addition, $E^{rns}$-EGFP mutations with RNase inactivation were also found to block NDV-mediated induction of IFN-$\beta$. These evidences establish a novel function for CSFV $E^{rns}$ glycoprotein in counteraction of the IFN-$\beta$ induction pathway.

• Korean Journal of Veterinary Research
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• v.52 no.4
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• pp.213-221
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• 2012

A total of 18 Newcastle disease virus (NDV) isolates that were recovered from 1949 through 1997 were characterized and pathotyped. All viruses were highly virulent as determined by intracerebral pathogenicity indices ${\geq}1.81$ in day-old. These pathotypes are typical for viscerotropic velogenic NDV (VVNDV) pathotype viruses. Some differences were observed for the chicken red blood cell elution rate and thermostability of the hemagglutinin at $56^{\circ}C$. Three antigenic groups were identified by a hemagglutination-inhibition assay using NDV monoclonal antibodies. And the predominant gross lesions were as follows: discharge from the nasal cavity, tracheal mucus, petechial hemorrhage in the heart fat, kidney urates and hemorrhage with or without necrosis in the gastrointestinal tract. Severe hemorrhagic or necrotic lesions were also noted in the lymphoid organs and were localized primarily in the spleen and cecal tonsil. However, differences in the occurrence and frequency of the gross lesions were observed between the virus strains. Among them, NDV strains that induced neurological symptoms belonged only to genotype VI. This strain had spread throughout Korea during the late 1980s to the 1990s, which suggests that specific VVNDVs genotypes might result in neurological symptoms.

• Korean Journal of Poultry Science
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• v.22 no.2
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• pp.85-95
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• 1995

This study was conducted to investigate the immune response of layers fed diets supplemented with excess micronutrients, i.e., vitamin A, methionine, Zn, Cu, and Fe to the inoculation of Newcastle disease vaccine(NDV) or infectious bronchitis vaccine(IBV). The antibody titer against the NDV increased immediately after the inoculation and stayed high during the next 6 wk. On the other hand, The antibody titer against the IBV increased after 4 wk of inoculation The IgM level increased rapidly after 1 wk of NDV inoculation, however, it decreased after 5 wk of inoculation. The IgA displayed similar pattern to that of IgM in response to NDV inoculation. The pattern of IgM change after IBV inoculation was similar to that when layers were treated with NDV. However, IgA level changed earlier than did IgM. The IgG response to the NDV and IBV was very weak compared to the other immune responses. The excess supplementation of micronutrients to the diets of layers inoculated with NDV elicited favorable antibody titer and immune response compared to the layers fed the control diet. The excess Zn, however, allowed the layers to have higher antibody titer for the 4-wk period after NDV injection: after that they showed no effect of extra-Zn. The immune responses of layers fed excess vitamin A, Cu, methionine, and Fe were markedly higher in IgA and IgG than the control layers. The excess Zn, however, did not bring about any favorable result. No difference was detected in IgG level between control and micronutrients-treated groups.

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.565-573
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• 1998

To study the specific tools for the diagnosis of Newcastle disease virus (NDV) in chicken, polymerase chain reaction (PCR) and its presumable conditions were evaluated for the detection of hemagglutinin-neuraminidase (HN) gene of NDV RNA. For these purposes, Kyojeongwon strain of the NDV was propagated in allantoic cavity of SPF embryonating chicken eggs, and viral RNA was extracted from fractionated virus after the allantoic fluids were ultracentrifuged with sucrose gradient. The first-strand cDNA was then made for the HN gene of NDV RNA by reverse transcription at $42^{\circ}C$ for 1 hour using specific primer complementary to the HN gene. The single-stranded cDNA was used as template in the PCR of the HN-DNA, and various conditions of the PCR were evaluated to set up method for the specific detection of the HN-DNA. The PCR conditions promising for the detection of HN gene consist of preheating at $94^{\circ}C$, 5 min, 30 cycles of denaturation at $94^{\circ}C$, 1 min, annealing at $55^{\circ}C$, 1 min and polymerization at $72^{\circ}C$, 2 min, and a cycle of extension at $72^{\circ}C$, 5 min. when NDVs of allantoic fluids without fractionation were applied to the above PCR condition, the HN genes were detected effectively not only from Kyojeongwon but from other velogenic strains such as Herts and a field isolate.

• Parasites, Hosts and Diseases
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• v.36 no.2
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• pp.121-126
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• 1998

Hemagglutination-inhibition titers (log2) to Newcastle disease (ND) vims were chronologically observed in chicks, which were orally inoculated with 5 × 105 oocysts of Cwptospori,drum bcileyi at 2 days of age and subsequently vaccinated with inactivated ND virus at 4 and 21 days postinoculation. In general, the titers were considerably lower in the infected chicks than those in the uninfected control throughout the experimental period (p < 0.01), and rapid negative seroronversions were observed in the infected chicks. The titers reached a peak on weeks 2 and 4 post-booster-vaccination in the control and infected chicks, respectively. Thus, C. bciLeWi infection was shown to have an immunosuppressive effect on ND vaccination when the agent was given to 2-day-old chicks. It is suggested that C. bniLeWi infection in chicks may increase the host susceptibility to ND virus.

• Korean Journal of Veterinary Service
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• v.26 no.3
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• pp.215-219
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• 2003

This study was conducted to investigate the similarity between hemagglutination inhibition (HI) test and enzyme-linked immunosorbent assay(ELISA) titers and sample to positive ratio (S/P ratio) of Newcastle disease(ND) virus. To perform this study, the 372 sera of broiler chicks and 120 sera of layers and breed chicks were collected from slaughter house and farms, respectively. As a result of HI test out of different chicks, the positive percentage of ND antibody titer of broiler, layer and breeder, when a standard positive HI titer were '2', was 84.4%, 100% and 100%, respectively. The positive percentage of ND antibody titer by ELISA was shown 38.4%, 100% and 100% and S/P ratio were also shown 81.5%, 98.2% and 99.2%, respectively. The results of comparative survey with same sera by two experimental methods were as follows; In low HI titer, ELISA titer was not similar to HI titer, but S/P ratio was similar to it. In high HI titer, ELISA titer was not similar to HI titer. Therefore, HI titer was more similar to S/P ratio than ELISA titer.

• Korean Journal of Veterinary Research
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• v.25 no.2
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• pp.155-165
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• 1985

Effects of binary ethylenimine (BEI) treatment on the inactivation of infectivity and hemagglutinin of Newcastle disease virus (NDV) were studied in comparison with those of formalin treatment. Immune responses of chickens vaccinated with BEI-inactivated NDV vaccines were also investigated. The results were summarized as followings; 1. Complete loss of infectivity of NDV (Bl) was observed at 3, 7, and 24 hours after the treatment at $37^{\circ}C$ with BEI concentrations of 0.01M, 0.005M and 0.001M, respectively. 2. The hemagglutinin activity of NDV (Bl) remained constant when treated with 0.01M BEI at $37^{\circ}C$. However, it gradually decreased when treated with 0.1% or 0.2% formalin at $37^{\circ}C$. 3. When 4-week-old chickens were vaccinated with NDV vaccines prepared from Bl or Miyadera strains of NDV, inactivated with 0.1M BEI and adsorbed to aluminium hydroxide gel, favorable immune responses were observed throughout the 8 weeks of observation period. 4. When these chickens were revaccinated at 8 weeks after the first vaccination, strong anamnestic responses were evoked and the immunity maintained for 4 weeks of the observation. Though slightly bettor immune responses were observed after primary vaccination in chickens vaccinated with Bl vaccine compared with those vaccinated with Miyadera vaccine, the differences were not significant. 5. On the electron microscopy, BEI (0.01M) gave least effect to the envelope as well as capsid of NDV.