• 대한바이러스학회지
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• 제29권1호
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• pp.33-38
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• 1999

Retroviral vector provide a highly efficient method for gene transfer into eukaryotic cells. This vector system can be divided into two components; the retroviral vector itself and the retroviral packaging cell line. The key improvement in the design of these two components are, focused on two aspects; the reduction of helper virus production and high titer-virus. We used PA317 for retrovirus packaging cell line, for its high producibility of viral titer. To test the ability of the vectors to generate high titer-virus, we have chosen four different retroviral vectors; LN, LNSX, LNCX and LXSN. To test easily the viral titer, we have made recombinant construction with CD4 and CD8, checked their viral titer and stained their surface expression. LXSN which contain SV40 early promoter in front of neo gene showed best results in viral transient transfection assay, dot blot assay and surface expression. In addition, recombinant containing CD8 generally showed much higher viral titration and surface expression than CD4.

• 한국수산과학회지
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• 제52권6호
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• pp.644-649
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• 2019

Killed vaccines, developed by inactivation with formalin, have been investigated for many fish viruses. In this study, the inactivation of viral hemorrhagic septicemia virus (VHSV) by formalin was investigated based on the infectivity titer. When viral cell culture supernatants were used, the infectivity titer decreased 1,000-fold at 1 d after treatment with 0.1% (v/v) formalin, but was below the detection limit at 7 and 14 d. Moreover, neither the N nor G gene were detectable by RT-PCR immediately after formalin treatment. In western blot analysis, N protein was not detected by rabbit antiserum against VHSV KR-9225 from 2 d after formalin treatment. On the other hand, when we used a virus that was purified and concentrated ~100 times, the infectivity titer was maintained at 10^6.05 TCID₅₀/mL, even at 14 d after formalin treatment, and no change in the viral structural proteins was observed. This study provides important data on the production and use of formalin-inactivated vaccines.

• 대한수의학회지
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• 제50권3호
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• pp.205-211
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• 2010

Fifty young calves, about five to six months old purchased from nation-wide were investigated with the prevelance of neutralizing antibody (Ab) of infectious bovine rhinotracheitis virus (IBRV), parainfluenza 3 virus ($PI_{3}V$), bovine viral diarrhea virus (BVDV) and bovine respiratory syncytial virus (BRSV). The positive detection ratio of neutralizing Ab against IBRV was only 3% and two of positive samples showed low antibody titer (below 2). Ab against BRSV showed 48% of positive ratio and among 24 positive samples, antibody titer of 23 samples were below 3. But in the case of BVDV, 68% of samples were positive and 23 samples appeared to possess high antibody titer, above 4 and the antibody titer of five samples were above 8. The highest positive result came from $PI_{3}V$. The positive ratio in the samples investigated in this study was 72%, but the antibody titer of positive samples were generally below 3 (77.8% in positive samples).

• 한국동물위생학회지
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• 제14권2호
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• pp.148-153
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• 1991

To investigate epidemological sitution of bovine viral diarrhea infection, serological survey in cattle being raised in Young Dong province were conducted. Bovine sera collected ramdomly from August 1990 to December 1990 were tested for bovine viral diarrhea virus serum neutralizing antibody titers. The results were as follows 1. BVDV SN antibody levels were considerably varies and positive rate was 58(108 heads out of 186) 2. BVDV SN antibodies to breeds of cattle was various and positive rates showed that diary cattle, beef, native cattle(Korean) were 67.52%, 59.38%, 27.00％ respectively followed in that order. 3. In the regional prevalence of BVD SN antibodies in cattle, Alpine(92％) was the highest, Young Dong south(59%) middle(44%), and North 30% followed in that order 4. In the age relatated prevalence of BVD SN antibodies, the younger than 6 month old group was the highest 65.7%, and older than 25 month old group was also at 62.2％. Then, 7 to 12 moth old group and 13 to 24 month old group showed to 58.5%, 52.1％ respectively. 5. The geometric mean titer (log2) of 108 cattle serum samples showing positive BVD SN antibodies was 4.3. 6. In the geometric mean titer(log2) according to age, younger than 6 month old group (5.2) was the highest, then 7 to 12 month old group 2.8(SD=1.94 standard deviation) was lowliest.

• 한국어병학회지
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• 제31권2호
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• pp.81-85
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• 2018

Fetal bovine serum (FBS) is an essential element of cell growth and can also affect the viral replication. In this study, we tried to find out whether FBS concentration affects the viral infectivity titer of IHNV and IPNV. EPC cells were suspended with MEM supplemented with various concentrations of FBS (MEM0, MEM2, MEM5 and MEM10) and cultured in 96-well plate. Each virus was 10-fold diluted virus and inoculated in 96-well plate. The highest infectivity titer of IHNV was $10^{7.88}\;TCID_{50}/mL$ in 96-well plate using MEM5 and the lowest one was $10^{7.30}\;TCID_{50}/mL$ in 96-well plate using MEM10. The highest infectivity titer of IPNV was $10^{7.47}\;TCID_{50}/mL$ in 96-well plate using MEM5 and the lowest one was $10^{6.97}\;TCID_{50}/mL$ in 96-well plate using MEM10. This study showed that not only 0% FBS but 10% FBS leads low infectivity titer of IHNV and IPNV. Therefore, it is considered that the desirable concentration of FBS is 2% or 5% for measurement of infectivity titer of IHNV and IPNV.

• 대한수혈학회지
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• 제23권2호
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• pp.152-161
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• 2012

배경: 2012년 1월부터 국내에 신규로 도입되는 고위험군 바이러스 검사시약은 국내 검체를 이용한 성능 시험분석을 실시하여 식품의약품안전청 허가를 득하도록 일부 규정이 개정되었다. 이러한 바이러스 진단시약의 성능시험과 품질관리 규정을 이행하기 위해서는 국내 검체에서 유래된 국가표준물질이 필요하다. 이에 본 연구에서는 바이러스 핵산증폭검사시약의 성능평가와 품질관리를 위하여 다양한 농도로 구성된 HBV, HCV와 HIV의 핵산증폭검사용 혈장유래 표준물질(plasma working standards)을 제조하고자 하였다. 방법: 수혈 부적격의 HCV RNA 양성혈장 43단위, HCV RNA 양성혈장 25단위, 그리고 HIV RNA 양성혈장 26단위에 대해 핵산 정량검사와 유전자형 검사를 실시하였다. 이를 바탕으로 국내에서 유행하는 바이러스의 유전자형을 가진 고농도의 원료혈장을 선정하였다. 또 표준물질의 다양한 농도는 국내외 검사시약의 검출범위에 근거하여 적정한 농도범위를 선택한 후, 다양한 농도로 원료물질을 희석하고, 분병 처리 한 후 정량적으로 분석하였다. 결과: HBV, HCV와 HIV의 체외진단분석기용 핵산증폭검사의 성능평가용 plasma working standards는 총 13종의 다양한 농도물질로 제조되었다. 결론: 국내에서 혈액관련 고위험군 HBV, HCV와 HIV의 체외진단용 핵산증폭검사 시약의 성능 평가에 필요한 바이러스 핵산 검사용 국가표준물질을 처음 제조하여 그 기술을 수립하였다.

• 생명과학회지
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• 제27권3호
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• pp.283-288
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• 2017

양돈산업에 있어 돼지 써코바이러스 2형(PCV2)의 복합감염으로 인한 이유자돈의 질병 피해가 막대하다. PCV2 감염에 대한 숙주의 민감도는 상이한 것으로 알려져 있으며, 따라서 숙주의 민감도를 구분하는 것은, 이를 이용한 숙주의 저항성 향상 연구에 필수이다. 본 연구의 목적은 이유자돈군의 혈액 내에서 PCV2 바이러스에 대한 숙주의 민감도를 구분 짓고 구명하는데 있었다. 본 연구에서는 자연적으로 바이러스에 감염된 10주령의 이유자돈군으로부터 혈청을 채취하여 PCV2 바이러스량과 항체가를 측정하고 혈구분석을 실시했다. 또한, 측정된 PCV2 바이러스량과 항체가를 기준으로 자돈군 내에서 저항성군과 민감성군을 선정하였고, 통계분석결과 저항성군에 비해 민감성군에서 백혈구 수가 현저히 줄어든 것을 확인하였다. 본 연구를 통해서 PCV2 감염에 대한 돼지의 민감도를 구분짓기 위한 PCV2 바이러스량과 항체가를 이용한 복합기준을 제시할 수 있었으며, 이유자돈군의 PCV2 관련 질병저항성 및 백혈구감소증을 확인할 수 있는 방법을 마련하였다.

• Journal of Animal Science and Technology
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• 제63권6호
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• pp.1223-1231
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• 2021

Regulator of G protein signaling 16 (RGS16) is known to be associated with porcine circovirus type 2 (PCV2). PCV2 associated disease (PCVAD) is a serious problem in the swine industry. The representative symptoms of PCVAD are high viral titer proliferation and decreased average daily gain. In this study, we identified single nucleotide polymorphisms (SNPs) in the RGS16 region, including the upstream region. Of the 22 identified SNPs, rs332913874, rs326071195, and rs318298586 were genotyped in 142 Yorkshire pigs. These SNPs were significantly associated with the PCV2 viral load. Moreover, the haplotype combination was also related to the PCV2 viral load. The haplotype and diplotype analysis also had a significant difference with the PCV2 viral load. Taken together, our results suggest that RGS16 SNPs considerably affect the PCV2 viral load.

• 한국동물위생학회지
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• 제37권4호
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• pp.273-280
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• 2014

Investigations of hematologic and canine distemper virus, parvovirus antibody titer for DongGyeongi were performed. This study was conducted to determine into feeding and management blood values on DongGyeongi. Blood samples were collected from 110 healthy dogs (male 60, female 50). The diagnostic virus disease and hematologic results were classified by age, sex, color. Although gender differences were not apparent, complete blood cell counts analyses were performed and analyzed accordingly. Statistically significant differences (P<0.05) specific to age (<2). Also, The canine distemper virus and parvovirus antibody titer were correlation to age dependent (P<0.05). In conclusion, data obtained from this study may be valuable as a standard for interpretation of the results in hematologic and major viral antibody titer analysis of DongGyeongi populations. For the management of DongGyeongi, the programs will be used for the epidemic disease prevention.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.315-319
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• 2003

A novel method is developed to yield virus titers in 10 h, is easy to .perform using 96-well plates, and applicable to both any Autographa californica nucleopolyhyderovirus (AcNPV) and Bombyx mori nucleopolyhedrovirus (BmNPV)-based recombinant baculovirus. This assay uses an antibody to a DNA-binding protein to detect the infected cells via immune-staining. The titer is determined by counting foci produced due to infection of virus under a fluorescent microscopy. The required incubation period was shortened considerably because infected cells expressed viral antigens at the post infection time of 4 h. Therefore, 10 hours were enough to estimate the virus titer including virus infection time, insect cell culture, and estimation of virus titer.