• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.77-82
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• 1992

A noncytopathic bovine viral diarrhea virus(NC BVDV) strain isolated and purified from persistently infected primary bovine fetal lung(BFL) cells was studied by biophysical methods. The buoyant density of particles of the NC BVDV strain was shown to be between 1,090 and $1,114g/cm^3$ and the maximum virus infectivity occured at $1,098g/cm^3$. Immunoelectron microscopic examination by using the partially purified virus revealed regular spherical particles 30~80nm in diameter. Differences in the genomic size of cytopathic and noncytopathic BVDV from infected cells were not found. A comparison of viral proteins of a noncytopathic and cytopathic strain(NADL) by immunoprecipitation using monoclonal antibody indicated that NC BVDV, compared to cytopathic NADL, was cell associated.

• Pediatric Infection and Vaccine
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• v.16 no.1
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• pp.61-72
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• 2009

Purpose : We evaluated the clinical features of Norovirus gastroenteritis compared with Rotavirus gastroenteritis in hospitalized children. Methods : We detected causative agents in 3,261 samples of children hospitalized with gastroenteritis symptoms at a single center of pediatrics between 2005 and 2006. Among 266 and 303 samples which tested positive for Norovirus and Rotavirus, we selected 73 and 182 samples of children with relatively pure gastroenteritis symptoms and retrospectively analyzed the corresponding medical records. Results : The male-to-female ratio of the Norovirus (+) and Rotavirus (+) groupswas 1.43:1 and 1.56:1 both groups were predominantly in males. The mean age of the Norovirus (+) and Rotavirus (+) groups was 36.7 and 24.4 months, respectively the children in the former group were older than the children in the latter group. The incidence in the Norovirus (+) group was more concentrated in the winter. The symptoms in the Norovirus (+), in decreasing order, included vomiting, diarrhea, and fever. The duration of vomiting, diarrhea, and fever was 2.1, 1.2, and 1.2 days. The maximum number of episodes of vomiting and diarrhea per day was 3.5 and 4.5, respectively. The severity score was 10.16. The symptoms inthe Rotavirus (+) group, in decreasing order, included diarrhea, vomiting, and fever. The duration of diarrhea, vomiting, and fever was 2.2, 4.3, and 2.2 days, respectively. The maximum number of episodes of vomiting and diarrhea per day was 3.3 and 6.5, respectively. The severity score was 11.9. The severity in the Norovirus (+) group was somewhat lower than the Rotavirus (+) group. The younger the child, the more severe the symptoms in the Norovirus (+) group. There was no difference between mono-and co-infection in severity and between the two groups regarding the hematologic findings. Conclusion : Based on the findings reported herein, additional studies about prophylaxis, as well as the epidemiology and clinical features of pediatric Norovirus gastroenteritis, are required.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.4
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• pp.320-324
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• 2001

According to the rapid growth of computer and internet recently, A hacking to steal infonnations and the computer vinls to destroy the data in computer are now prevailing in the whole world. A study of methods to protect the data of computer is in progress. One of the study is constmction of computer immune system using biological immune system tbat has ability of removal and protection from extemal invasion. In this paper, we make a change detection algorithm which is based on ability of distinction between self and nonself in T-cytotoxic cell that is one of biological immune cell. In algorithm, MHC receptors are composed of a part of self-file that is recognized as itself and those shall distinguish self-file from the changed file. As a result of applying this algorithm to the changed self-files, we prove the efficacy of detection of the self-files changed by computer virus and hacking.

• Korean Journal of Plant Tissue Culture
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• v.24 no.5
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• pp.313-317
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• 1997

Leaf segments of the potato (Solanum tuberosum L.) genotypes, ND860-2, Norchip, Russet Norkotah, Goldrush, and Norqueen Russet were transformed with the coat protein gene of potato virus Y (PVY). The white-skinned genotypes, ND860-2 and Norchip, were easily transformed and regenerated into shoots, whereas the three russet-skinned genotypes had low frequencies of regeneration. Transformed shoots were generally recovered in four to six weeks. Antibody to PVY coat protein detected a single band of 30 kD in western blots of transgenic plants. Transformed plants had a normal phenotype in the greenhouse and many showed a delayed buildup of PVY following inoculation. Several transgenic lines had negative ELISA readings 85 days after inoculation. Transgenic lines which did not show detectable levels of PVY antigen will be further tested for resistance to PVY.

• Research in Plant Disease
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• v.19 no.3
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• pp.220-225
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• 2013

For quarantine purpose, we developed the RT- and nested PCR module of Tomato black ring virus (TBRV), Arabis mosaic virus (ArMV), Cherry leafroll virus (CLRV) and Grapevine fanleaf virus (GFLV). The PCR modules, developed in this study make diagnosis more convenient and speedy because of same PCR condition. And also, the methods are more accurate because it can check whether the result is contamination or not using the mutation-positive control. We discard or return the 27 cases of Nepovirus infection seed by employing the module past 3 years. This study provides a rapid and useful method for detection of four quarantine plant viruses.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.321-326
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• 1994

Korean isolate, porcine epidemic diarrhea virus (KPEDV-9) was adapted through serial passages in vero cell. The viral yield reached up to $10^{5-6}$ $TCID_{50}/ml$ at the passage level of 90th. The cell adapted virus was characterized through genetic and morphological examinations. The RNA extracted from virus infected cell revealed the presence of RNA band with molecular size of >20Kb. The electron microscopic examination on purified virus showed the pleomorphic appearance of enveloped particles with 5-10nm surface projections, which fit with the shape of coronavirus. The etiological survey on swine diarrhea by immunofluorescence test(FA) indicated 17.5% positive rate on the PEDV infection. In addition, the incidence were detected both in piglets within two weeks old as well as fattening pigs. Serological survey by ELISA revealed the overall 45% positive result, thus, indicating the PEDV infection are widespread throughout this country.

• Journal of Life Science
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• v.13 no.2
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• pp.197-205
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• 2003

We detested waterborne enteric viruses from the raw water and tap water in Busan metropolitan city by the total culturable virus assay of EPA standard method. According to the results of survey from July 2001 to November 2002, thirteen out of twenty one in raw water samples were positive (61.9%) for enteric viruses and all of the treated water and tap water samples were negative. The enteric viruses in raw water were mainly distributed through the summer to the earl y winter, suggesting the seasonal characteristics of virus distribution in water The titer of enteric viruses per 100 liters of the raw water was ranged from 1.92 to 9.70 MPN by TCVA-MPN program. The isolated viruses were identified as either human poliovirus type 1 or enteroviruses by the immunofluorescent assay.

• Pediatric Infection and Vaccine
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• v.14 no.2
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• pp.145-154
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• 2007

Purpose : Rotavirus is one of the most important etiologic agents of nosocomial infections among the neonates. This study was designed to investigate nosocomial rotavirus infection in neonates who were admitted to a postpartum-care center after birth. Methods : From March 2005 to September 2006, 957 healthy neonates were examined for rotavirus antigen in stool by immunochromatographic method and 216 neonates were rotavirus antigen positive within 24 hours after admitted to a postpartum-care center. We reviewed the nursing charts retrospectively such as characteristics, monthly distribution, birth hospitals, delivery methods, feeding types and clinical manifestations. Results : Among 957 neonates, 216 neonates (22.6%) were rotavirus antigen positive and there were no differences in sex, birth weight, gestational age. Monthly positive rate of rotavirus antigen showed diversity from 10% to 36%. According to birth hospitals, positive rate showed diversity from 3.5% to 53.6%. Out of 957 neonates, 655 cases (68.4%) were born of vaginal delivery and mean hospitalized duration was 2.4 days, 302 cases (31.6%) were born of cesarean section and mean hospitalized duration was 5.7 days. 17.6% of vaginal delivery and 33.4% of cesarean section were rotavirus antigen positive. The positive rate was higher in neonates by cesarean section than vaginal delivery (P<0.001). According to feeding types, positive rate of rotavirus antigen was lower in breast-fed group than formula-fed group (P<0.001). Proportion of symptomatic case among rotavirus antigen positive was 34.7%. Most common clinical manifestation was diarrhea (61.3%), following poor feeding (45.3%), fever (40.0%), vomiting (25.3%), delayed weight gain (12.0%), and decreased urine amount (5.3%). Conclusion : Some neonates were already infected before admission to a postpartum-care center. Without meticulous management, nosocomial rotavirus infection would transmit rapidly in a postpartum-care center spreading to the community. Recommendation of breast-feeding, routine rotavirus screeing test with or without symptom, and isolation of all rotavirus antigen positive neonates in a postpartum-care center seem to be necessary. Also attentive hygiene education and further investigations of rotavirus infection in a postpartum-care center would be needed.

• Pediatric Infection and Vaccine
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• v.9 no.2
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• pp.201-207
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• 2002

Purpose : We analyzed clinical features and causal viruses of acute lower respiratory tract infections(LRTIs) in order to improve the management of these infections. Methods : From end of April to early May 2001, amongst 30 children at a local institute for children's adoption and welfare, 13 were admitted to the hospital with the diagnostic impression of acute LRTIs. Nasopharyngeal aspirates were sent in Seoul National University Hospital for viral culture of respiratory syncytial virus(RSV), adenovirus, parainfluenza virus. Results : One or more viral agents were identified in 4 cases(30.7%) : were RSV(15.4%), adenovirus(7.7%), and a mix of these two viruses(7.7%). Initial symptoms were fever(69%), cough(100%), tachypnea(54%), chest retraction(69%), rale(85%) and wheezing(15%). Leukocytosis was noted in 23%, CRP increased more than 10 mg/L in 46%. Chest X-ray abnormalities were 69%. Conclusion : Although viruses were identified in 30.7%, further studies should be made for prevention and treatment of acute viral LRTIs.

• Pediatric Infection and Vaccine
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• v.14 no.1
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• pp.91-96
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• 2007

Purpose : This study was performed to evaluate a new rapid diagnostic kit (BIOLINE $RSV^{TM}$; Standard Diagnostics Inc., Yongin, Korea), a lateral-flow immunoassay, in the detection of respiratory syncytial virus (RSV) from the nasopharyngeal aspirates (NPA) of children with lower respiratory tract infections (LRTIs) in comparison with other diagnostic methods. Methods : Three hundred and nineteen NPAs were selected from a large pool of NPAs that had been obtained from children with LRTIs. All specimens had already been tested for RSV by culture and immunofluorescent (IF) test, and had been kept frozen. Tests with BIOLINE $RSV^{TM}$ were performed at least twice. All who conducted the experiments or interpreted the test results were blinded to the results of both culture and IF tests. Results : One hundred seven (97.3%) of 110 specimens that were positive for RSV by both culture and IF test, 29 (87.9%) of 33 that were positive by IF test only, 20 (76.9%) of 26 that were positive by culture only, and 140 (93.3%) of 150 that were negative by both methods were negative for RSV by BIOLINE $RSV^{TM}$. By combining the above results, the following 5 diagnostic values of BIOLINE $RSV^{TM}$ were determined in comparison with viral culture or IF test; sensitivity, 92.3% (156/169, 95% confidence interval [CI], 87.1-97.5%); specificity, 93.3% (140/150, 95% CI, 88.4-98.2%); positive predictive value, 94.0% (156/166, 95% CI, 89.5-98.5%); negative predictive value, 91.5% (140/143, 95% CI, 86.0-97.0%); and agreement, 95.9% (306/319, 95% CI, 92.1-99.7%), respectively. Conclusion : This study revealed that BIOLINE $RSV^{TM}$ demonstrated good sensitivity and specificity for the detection of RSV antigen from NPAs of children with LRTIs. Because of simple methods and quick results, this test may be useful for the diagnosis of RSV infection during the epidemic periods.