• Korean Journal of Veterinary Research
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• v.39 no.3
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• pp.531-537
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• 1999

The present study was carried out to investigate the pathogenicity and pathogenesis of wild rats(Rattus norvegicus), trapped in nature, intranasally infected with Aujeszky's disease virus(ADV/NYJ-1-87) by histopathology, immunohistochemistry and in situ hybridization(ISH). Fifteen rats inoculated intranasally were roughened haircoat, anorexia, listlessness, and depression second day after inoculation, and three rats died in 66-72 hours. Eight rats showed severe pruritus at the face that was accompanied by frequent face-washing movements of the forelegs, and then became violent and spasmodic for an hour or until they died. Four rats slowly recovered after showing mild clinical signs of the disease. Microscopic lesions in infected rats were characterized by meningitis, perivascular round cell infiltration, focal gliosis, and neuronal degeneration and necrosis. And intranuclear inclusion bodies were frequently detected in the cerebral cortex and medulla. Positive reaction to ADV by immunohistochemistry and ISH were detected in the following areas : trigermimal ganglion, brain, tonsil, nasal mucosa, spleen, lung and liver. The result has suggested that ADV intranasally infected in wild rats is followed by replication in epithelial calls of nasal mucosa and tonsil, then invade local lymph nodes by way of the lymphatics. It is also believed that the virus invades bipolar olfactory cells and trigerminal ganglion; and then spread into central nervous system.

• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.45-52
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• 2002

The acute phase serum protein response is a well-known general indicator of inflammation, trauma or other pathological conditions and its relevance for the monitoring of the health status of domestic animals is being increasingly realized. The changes in serum protein composition which occur after tissue damage represent a part of the systemic response of the injured animals which is mediated by pro-inflammatory cytokines such as TNF-$\alpha$, IL-6 and IL-1. These responses play a vital role in containing the tissue damage and enhancing the processes of repair and resolution. From a clinical perspective, the assay of acute phase proteins can provide a method for detecting inflammation. In animals, the most sensitive acute phase proteins are haptoglogin, serum amyloid A and at-acid glycoprotein in response to inflammatory condition. The aim of this study was to assess the diagnostic value of the concentrations of serum amyloid A(SAA) and haptoglobin(HP) in serum of pigs infected with Aujeszky's disease virus(ADV). Fifty pigs infected with ADV and 5 normal pigs were used in this experiment. The mean serum concentration of Shh of pigs infected with ADV was 96.8 $\pm$ 7.1 $\mu\textrm{g}$/㎖(range, 36.0∼187.5 $\mu\textrm{g}$/㎖) and that of normal pigs was 42.9$\pm$3.3 $\mu\textrm{g}$/㎖(range, 17.3∼127.8 $\mu\textrm{g}$/㎖). The mean serum concentration of HP of pigs infected with ADV was 1,164.4 $\pm$ 96.9 $\mu\textrm{g}$/㎖ (range, 790.2∼l,769.2 $\mu\textrm{g}$/㎖) and that of normal pigs was 675.4 $\pm$ 56.3 $\mu\textrm{g}$/㎖ (range, 650.0-690.4 $\mu\textrm{g}$/㎖). The mean concentrations of SAA and HP in serum of pigs infected with ADV compared with those of normal pigs showed approximately a two-fold. It was concluded that the concentrations of Shh and HP in serum may proved to be diagnostic marker of Aujeszky's disease.

• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.369-374
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• 1995

Aujeszky's disease virus(ADV) was inoculated intranasally into the Korean native goats to investigate pathological findings and pathogenesis of ADV infection by using of histological and immunohistochemical methods and in situ hybridization(ISH). Clinical signs of salvation, pyrexia, pruritus and staggering were followed by death with five days after inoculation, Pathoanatomical findings were edema of the lung and the urinary bladder with hemorrhage and congestion, petechial hemorrhages on the endo-and epicardium, renal congestion, moderate splenomegaly and cystic edema. Main microsocpic lesions observed in all infected goats were confined to the CNS and charcterized by perivascular cuffing with lymphocytes and macrophages, focal gliosis, neuronal degeneration and necrosis, and intranuclear inclusion bodies in the neurons and glial cells. Positive reactions to ADV were detected more frequently in the nuclei than in the cytoplasms of infected nerve cells in the CNS by immunohistochemistry and ISH. Frequenctly localized sites of ADV in the CNS were olfactory bulb, prietal cortex, callosal sulcus and corpus callosum. Positive reactions were also detected in the tonsillar epithelium, and alveolar macrophage and sloughed epithelium of the lung.

• Korean Journal of Veterinary Research
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• v.49 no.4
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• pp.329-334
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• 2009

Aujeszky's disease (AD) is a respiratory, infectious viral illness associated with high mortality, especially in neonatal piglets and has frequently been considered an economically important disease in many endemic countries. Although AD is still occurring in a geographically defined region in Korea, little attention has been paid to the economics of AD. In this study, partial budget technique was used to develop a simulation model to measure financial losses following the disease epidemic in a swine operation utilizing stochastic or deterministic parameters from the literatures and the index case herd of AD occurred in 2005, where available and applicable. For the infected case herd with a 12500-pig, the total economic loss for this operation was estimated to be about 199 million Korean won (95% confidence interval [CI] 148,645,000-250,741,000). Given net loss due to death of a pig at sow level was 119,000 won, total loss for the case herd with 1200 sows accounted for 143 million won (95% CI 92,599,000-193,729,000). The net loss of the death of one pig at growing and fattening level resulted in loss of 46,000 won (95% CI 40,000-53,000) and 126,000 won (95% CI 122,000-131,000), respectively. Taking into account for the number of pigs raised in the case herd, total loss amounted to 8 million won (95% CI 7,167,000-9,347,000) and 12 million won (95% CI 11,959,000-12,891,000), for growers and fatteners, respectively, assuming 63% of saved feed intake when a pig dies halfway through the respective period. Under the model's assumptions, suckling pig mortality was the major factors of loss in estimating the economic consequences (approximately 71.8% of the total loss). The high economic losses of a herd infected with AD suggest that the effective and region-specific control measures should be implemented in disease endemic foci.

• Korean Journal of Veterinary Research
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• v.49 no.2
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• pp.149-155
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• 2009

The objective of this study was to analyze data from the planned national serological monitoring program for Aujeszky's disease (AD) using a simulation model to evaluate probable outcomes expected in the sample derived from the simulated herds at predefined within-herd prevalence and herd prevalence. Additionally, prevalence at animal- and herd-level estimated by the stochastic simulation model based on the distributions of the proportion of infected herds and test-positive animals was compared with those of data from a national serological survey in 2006, in which 106,762 fattening pigs from 5,325 herds were tested for AD using a commercial ELISA kit. A fixed value of 95% was used for test sensitivity, and the specificity was modeled with a minimum, most likely and maximum of 95, 97 and 99%, respectively. The within-herd prevalence and herd prevalence was modeled using Pert and Triang distributions, respectively with a minimum, most likely and maximum point values. In all calculations, population size of 1,000 was used due to lack of representative information. The mean number of infected herds and true test-positives was estimated to be 27 herds (median = 25; 95% percentile 44) and 214 pigs (median = 196; 95% percentile 423), respectively. When testing 20 pigs (mean of 2006 survey) in each herd, there was a 3.3% probability that the potential for false-positive reactions due to less than 100% specificity of the ELISA test would be detected. It was found that the model showed prevalence of 0.21% (99% percentile 0.50%) and 0.5% (99% percentile 0.99%) at animal- and herd-level, respectively. These rates were much similar to data from the 2006 survey (0.62% versus 0.83%). The overall mean herd-level sensitivity of the 2006 survey for fattening pigs was 99.9%, with only a 0.2% probability of failing to detect at least one infected herd.

• Korean Journal of Veterinary Research
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• v.49 no.1
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• pp.45-57
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• 2009

The molecular genetic characterization of Aujeszky's disease virus (ADV) Yangsan strain (ADVYS), a Korean isolate, was investigated by analyzing the electrophoresis patterns and the physical maps of the viral DNA digested with various endonucleases. To establish DNA library for ADV-YS, twelve major BamHI restricted segments were cloned. Each location of the segments in the ADV genome was determined by sequence comparison with the sequences reported in Genbank and those sequences of the both termini of the segments. Physical maps were constructed based on the electrophoresis patterns of the digested viral DNA by restriction endonuclease and the results of Southern blot analyses with various DIG labeled probes originated from those of enzyme restricted segments of virulent (Shope) and avirulent (Bartha) strain. Comparing ADV-YS with a standard strain of Kaplan in the maps of restriction enzymes, following major respects were identified: (i) disappearance of BamHI restriction site between the first and second BamHI segments, (ii) creation of the BamHI restriction site in the fifth segment, and (iii) generation of the BglII site in the unique short (US) region. The genome of ADV-YS also contains a type 2 herpesvirus DNA molecule (in which the US region only inverts itself relative to the unique longregion) like all other ADV strains except Norden strain(type3), analyzed up to date. The size of the ADV genome estimated from the sizes of the restriction enzyme fragments, was approximately 145.3 kb (BamHI) or 145.4 kb (BglII). BamHI enzyme cleavage patterns were compared among the five Korean ADV isolates: Yangsan, Yongin, Dangjin, Jincheon and Iksan strains. Difference either in the number or in the size of the DNA fragments, suspected regions of termini of IR and TR, could be detected among all five strains.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.845-858
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• 1996

The purpose of this study was to establish early diagnostic methods for the detection of Aujeszky's disease viral antigens and nucleic acid in nasal cells, and buffy coats from experimentally infected living pigs by a combination of immunocytochemistry, in situ hybridization with digoxigenin(DIG)-labled probe and electron microscopy. Forty days old piglets were inoculated intranasally with $10^{7.0}TCID_{50}$ of Aujeszky's disease virus (ADV, NYJ-1-87 strain). The viral antigens and nucleic acid of ADV were detected in nasal cells, and buffy coat for 20 days after inoculation by immunocytochemistry, in situ hybridization with DIG-labeled probe and electron microscopical method. The results were compared with conventional methods such as a porcine Aujeszky's disease serodiagnostic(PAD) kit, neutralization test(NT) and virus isolation. 1. The viral antigens, nucleic acids and capsids of ADV were detected in nasal cells, buffy coats from 3 days to 20 days after inoculation by immunocytochemistry, in situ hybridization with DIG-labeled probe and electron microscopy, respectively. 2. When viral antigens were detected by the immunocytochemical technique, a diffuse brown deposit was observed in the nucleus and cytoplasm of nasal cells, buffy coats and PK-15 cells under a microscope. 3. DIG-labeled DNA probe was prepared by amplification of conserved sequence of recombinant ADV-gp50 clone with polymerase chain reacction. When ADV-DNA was detected by ISH with DIG-labeled probe, purplish blue pigmentation were observed in the nuclei and cytoplasms of ADV-infected cells under a microscope. Positive signals were observed in nasal cells and in the buffy coat and PK-15 cells at the first day after inoculation. 4. Where ADV-capsids were detected by transmission electron microscopical method, aggregation of capsids was observed in the nuclei and cytoplasms of nasal cells, buffy coats and PK-15 cells. The results suggested that these methods were considered as the highly sensitive and reliable tools for rapid and confirmative diagnosis of Aujeszky's disease in living pigs.

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.417-423
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• 2007

Serological surveillance programs in animal populations are becoming increasingly important to estimate prevalence of a specific disease and subsequently to document disease-free status in a region or a country. For these purposes, the programs need to be based on both theoretical and economical aspects from the designing phase. From Aujeszky's disease (AD)-eradication program point of view, group of animals (aggregates, herds) not individual animal is the more important sampling unit of concern. In this study the authors therefore attempted to compute an appropriate sample size tailored to a current surveillance program against AD, assuming that the goal of this program is either herd-level prevalence estimation or documentation of AD-freedom. For prevalence estimation, assuming a finite population with imperfect sensitivity (Se) and specificity (Sp) of ELISA kit for AD diagnosis, the number of herds present, expected herd prevalence, and desired accuracy for a certain level of confidence, sample size was estimated at herd-level in the first stage and individual animal-level in the second stage. A two-stage sampling design was used to calculate a sample size to indicate AD-freedom. In this instance, the computation was based on the possible detection of a predetermined prevalence at a certain herd-level Se and Sp. This study indicated that the sample size varied with predetermined confidence, tolerance, Se and Sp at herd- and animal-level, and within- and among-herd prevalence. In general, smaller sample size was required to estimate AD prevalence than to document of AD-freedom. Compared to individual-based samples, two-stage sampling strategy requires a larger sample size to show disease-freedom. Statistical considerations including herd-level test characteristics when designing surveillance program also are further discussed.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.77-83
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• 1994

Three viral strains, causing CPE in porcine alveolar macrophage cell, were isolated from aborted fetus, serum from young pig showing blue-ear sign and lung of suspected pig, respectively. The differential diagnostic results showed no characteristics of Aujeszky's disease virus(ADV), hog cholera virus (HCV), Japanese encephalitis virus(JEV), porcine parvovirus(PPV) and encephalomyocarditis virus (EMCV). However, positive reactions were demonstrated by IFA using monospecific porcine antibodies against Lelystad virus. When the paired sera of experimentally inoculated swine with one of isolate, KPRRSV-l were tested by IPMA, the result indicated that the isolate was related to United States isolate than European LV.

• Korean Journal of Veterinary Research
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• v.46 no.3
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• pp.225-234
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• 2006

In the present study toxicity and immunostimulating activity of the lectin(KML-C), which was extracted from Korean mistletoe(Viscum album coloratum) were investigated in swine. To determine the toxicity, lectin was injected into thigh or cervical muscles of 4-week-old piglets(Landrace) and observed clinically and pathologically. For determination of the immnunostimulating activity, lectin($0.7{\mu}g/kg$ of body weight)-adjuvanted vaccine of Aujeszky's disease virus(ADV)(NYJ1-87) which was inactivated by 0.2% formalin was injected into the cervical muscle of antibody-negative piglets in the same age group. Subpopulation of the immune cells and serum neutralizing(SN) antibodies in the piglets were examined after vaccination, and resistance of the piglets against challenge by virulent NYJ1-87 was further examined. The results were also compared with those from piglets injected with aluminum hydroxide [$Al(OH)_3$]-adjuvanted vaccine of inactivated NYJ1-87 and NYJ1-87 vaccine without adjuvant, and the results are as follows. By injection of lectin with $30{\mu}g/kg$ of body weight to the thigh muscle, all of 12 piglets died after signs such as dyspnea, fever, systemic erythema and subcutaneous hemorrhages, and lesions pertaining to poisonous hepatitis and dysfunction of kidney were observed. By injection of lectin with $7{\mu}g/kg$ of body weight to the thigh muscle, all of 12 piglets showed signs such as edema and cutaneous hemorrhage in the injected area, lameness and depression, and lesions pertaining to poisonous hepatitis and dysfunction of kidney were observed. By injection of lectin with 1, 3 and $5{\mu}g/kg$ of body weight to the thigh muscle of each one piglet, signs such as congestion, induration and grayish coloration in the injected area, depression and inappetence were observed in all piglets. Toxic changes were also observed in the liver and kidney of piglets by lectin of 3 and $5{\mu}g$. By injection of lectin with 0.5 and $0.7{\mu}g/kg$ of body weight to the cervical muscle of each 9 piglets, all piglets were clinically normal and there were no significant changes in blood counts and chemistry values. Whereas, epithelial swelling and vacuolation of convoluted tubules were observed from one piglet injected with lectin of $0.7{\mu}g$, and necrosis and fibrosis of muscular fiber were observed in the muscle of one piglet injected with lectin of $0.5{\mu}g$. Only population of sIgM+ B lymphocytes increased among immune cells in all of 15 piglets immunized with lectin($0.7{\mu}g/kg$ of body weight)-adjuvanted vaccine, while compared to those in $Al(OH)_3$-adjuvanted vaccine and vaccine without adjuvant. No additional stimulation to the immune cells was recognized when lectin was added to $Al(OH)_3$-adjuvanted vaccine. In piglets immunized with lectin-adjuvanted vaccine, SN titers in reciprocal values for loge were 1.3-4.0 at 1-4 weeks after vaccination, which was similar to those with 1.0-3.3 by vaccine without adjuvant but lower than those with 2.0-5.7 by $Al(OH)_3$-adjuvanted vaccine. Also, no additional increase in the SN titers was recognized when lectin was added to $Al(OH)_3$-adjuvanted vaccine. Piglets immunized with lectin-adjuvanted vaccine were resistant to challenge by the virulent NYJ1-87 at 4 weeks after vaccination, and the SN titers reached to 5.0 one week after challenge, which was higher than those with 4.0 by vaccine without adjuvant but somewhat lower than those with 7.7 by $Al(OH)_3$-adjuvanted vaccine.