• Journal of the korean veterinary medical association
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• v.22 no.11
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• pp.695-700
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• 1986

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.230-232
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• 2004

In this paper, we investigated dielectric and insulation characteristics of epoxy resin which includes elastomers to improve mechanical property, as varied additive elastomer contents with 5[phr], 10[phr], 15[phr], and 20[phr]. We measured permittivity and tan $\delta$ at 1kHz of signal frequency and room temperature. And we also measured BVD(break-down voltage) and volume resistivities. According to the experimental results, it is appeared that when the additive elastomer contents are increasing, permittivity, volume resistivity, BVD and volume resistance are decreasing because elastomer remains inferior to epoxy resin on electrical properties.

• Journal of Animal Science and Technology
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• v.66 no.4
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• pp.781-791
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• 2024

Bovine viral diarrhea (BVD) is a single-stranded, positive-sense ribonucleic acid (RNA) virus belonging to the genus Pestivirus of the Flaviviridae family. BVD frequently causes economic losses to farmers. Among bovine viral diarrhea virus (BVDV) strains, BVDV-1b is predominant and widespread in Hanwoo calves. Reverse-transcription polymerase chain reaction (RT-PCR) is an essential method for diagnosing BVDV-1b and has become the gold standard for diagnosis in the Republic of Korea. However, this diagnostic method is time-consuming and requires expensive equipment. Therefore, Clustered regularly interspaced short palindromic repeats-Cas (CRISPR-Cas) systems have been used for point-of-care (POC) testing of viruses. Developing a sensitive and specific method for POC testing of BVDV-1b would be advantageous for controlling the spread of infection. Thus, this study aimed to develop a novel nucleic acid detection method using the CRISPR-Cas13 system for POC testing of BVDV-1b. The sequence of the BVD virus was extracted from National Center for Biotechnology Information (NC_001461.1), and the 5' untranslated region, commonly used for detection, was selected. CRISPR RNA (crRNA) was designed using the Cas13 design program and optimized for the expression and purification of the LwCas13a protein. Madin Darby bovine kidney (MDBK) cells were infected with BVDV-1b, incubated, and the viral RNA was extracted. To enable POC viral detection, the compatibility of the CRISPR-Cas13 system was verified with a paper-based strip through collateral cleavage activity. Finally, a colorimetric assay was used to evaluate the detection of BVDV-1b by combining the previously obtained crRNA and Cas13a protein on a paper strip. In conclusion, the CRISPR-Cas13 system is highly sensitive, specific, and capable of nucleic acid detection, making it an optimal system for the early point-of-care testing of BVDV-1b.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.163-167
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• 2007

Bovine viral diarrhea (BVD) is very important disease in cattle industry with a worldwide distribution. Detection and elimination of persistently infected calves with bovine viral diarrhea virus (BVDV) was valuable strategy for BVD eradication because those calves were main source for transmission. We surveyed persistent infection with BVDV by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) using whole blood and skin. Five hundred thirty nine Korean native calves were tested. Four calves (0.7%) were positive for BVDV antigen for both tests. Those calves remained positive for follow-up by RT-PCR and IHC. Therefore they were identified as persistently infected with BVDV. We confirmed that immunohistochemistry using skin biopsy samples was very useful tool to detect persistently infected calves with BVDV. As far as we know, this would be first report on persistent infection with BVDV in Korea.

• Proceedings of the Microbiological Society of Korea Conference
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• 2000.10a
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• pp.66-77
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• 2000

For a variety of viruses, the primary virus infection has been shown to prevent superinfection with a homologous secondary virus; however, the mechanism of exclusion has not been clearly understood. In this work, we demonstrated that BVDV -infected MDBK cells were protected from superinfection with a homologous superinfecting BVDV, one of the positive-sense RNA pestiviruses, but not with an unrelated rhabdovirus, such as vesicular stomatitis virus. Once superinfection exclusion was established by a primary infection with BVDV, the transfected infectious BVD viral RNA genome was shown to be competent for viral translation, but not viral replication. In addition, our results also demonstrated that upon superinfection, the. viral RNA genome of viral particles was not transferred into the cytoplasm of BVDV -infected cells. Using newly developed system involving rapid generation of the MDBK cells expressing BVD viral proteins, we subsequently found that expression of the viral structural proteins was dispensable for the block occurring at the level of viral RNA replication, but required for the exclusion at the level of viral entry step. Altogether, these findings provide evidence that the superinfection exclusion of BVDV occurs not only at the level of viral replication in which the viral replicase are involved, but also at the level of viral entry with which the viral structural proteins are associated, and that a cellular factor(s) play an essential role in this process.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.389-398
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• 1992

Molecular cloning was carried out on the Danish strain of bovine viral diarrhea virus(BVDV) to construct strategy for the diagnostic tools and effective vaccine of BVD afterwards. A recombinant DNA clone(No. 29) was established successfully from cDNA for viral RNA tailed with adenine homopolymer at 3'-end. $^{32}P$-labeled DNA probes of 300~1,800bp fragments, originating from the clone 29, directed specific DNA-RNA hybridization results with BVDV RNA. Recombinant DNA of the clone 29 was about 5,200bp representing 41.6% of the full length of Danish strain's RNA, and restriction sites were recognized for EcoR I, Sst I, Hin d III and Pst I restriction enzymes in the DNA fragment.

• Journal of the korean veterinary medical association
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• v.32 no.7
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• pp.418-425
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• 1996

최근에 소의 밀집사육, 빈번한 이동, 인건비상승에 따른 관리인력 부족 등으로 인해 과거에 비해 각종 질병의 발생이 증가되고 있으며 그중에서도 전염성 질병의 발생이 증가하고 있다. 또한 빠른 우군교체에 따라 과거에 비해 소들의 질병발생형태가 많이 변하고 있다. 소의 질병중 특히 바이러스성 질병은 근본적인 치료약제가 없기 때문에 한번 발생하면 빠르게 다른 지역으로 전파되는 경향이 있으며 소의 생산성저하를 야기시키는 가장 큰 원인이 되고 있다. 이러한 소의 바이러스성 질병은 IBR, BVD, PI-3감염증 등의 호흡기 질병, rotavirus, coronavirus감염증과 같은 소화기 질병 그리고 모기매개 바이러스에 의한 질병으로 크게 분류 할 수 있다. 특히 최근들어 모기매개 바이러스성 질병이 크게 문제시 되고 있으며 이들 질병으로 소 아까바네병, 츄잔병, 유행열, 이바라기병이 있다. 수의과학연구소에서는 매년 모기출현 전에 전국의 소 3,000두를 대상으로 모기매개질병에 대한 방어항체분포조사를 실시하고 있으며 그 결과를 이용하여 농촌진흥청에서는 금년 5월 소의 모기매개성 전염병의 발생주의보를 발령한 바 있다. 이같이 금년에도 발생이 예상되는 소 모기매개 바이러스성 질병의 예방과 대책에 대해 기술하고자 한다.

• Korean Journal of Veterinary Pathology
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• v.3 no.2
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• pp.73-76
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• 1999

The tissue distribution and cellular localization of viral antigen in the brain of aborted fetus with bovine viral diarrhea virus(BVDV) infection was studied; BVDV antigens was detected in spleen, kidney, lung, eyelid as well as brain. In the brain, the virus was recognized in neurons and non-neuronal cells in the cerebellum and cerebrum. Many cells in the superficial layer and occasional Purkinje cells had BVDV antigens. As well, BVDV was also found in the perivascular cells, vascular endothelial cells and smooth muscle cells in the vessels and neuroglial cells in the white matter. This finding suggests that BVD virus favors infect progenitor cells in the brain, notably in the superficial layer of cerebellum, and damage normal development of cerebellum, which leads to cerebellar hypoplasia.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.423-426
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• 2003

Congenital anomalies occur at low levels in Korean antive cattle. PCR and Serum neutrlizing test against BVD, Akabane virus, Ibaraki virus, Kasba virus were examined. The results were all negative. Gross anatomical analysis was carried aout. Congenital abnormal newborn calf had 2 atropic left hindlimbs, which was nor moved autonomosly. The length of 2 atropic hindlimbs was 72 em and 48cm respectively. Both of them were curved severely at joints. Affected limbs were developed in connective tissue but lack of muscular tissue. In the abdominal region right kidney was normal. But there were two left kidneys which was half size compared with normal kidney. One of them had polycysts. In skeletal region, affected left limb is defective of head of femur and tibia.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.419-422
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• 2003

Humeral hemimelia is a rare congenital anomaly characterized by deficiency of the humerus with relatively intact scapular. The holstein calf was healthy expecting the deformity of forelimb humerus. The examination of PCR and serum neutralizing test was carried about BVD, akabane virus, Ibaraki virus and Kasba virus in cattle. The results were all negative. Affected calf showed forelimb deformation. Other abnormalitis was not observed in brain, spinal cord, liver, kidney and other visceral organs. Amelia are very rare limb anomalies. We report on a Holstein calf with forelimb deficiencies. This case appears humeral anomalies with ulnar and radius aplasia in calf. The condition in these calves was considered the result of a recurrence of a genetic mutation affecting a putative hemimelia locus.