• Genomics & Informatics
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• v.11 no.1
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• pp.15-23
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• 2013

CD8+T cells are key factors mediating hepatitis B virus (HBV) clearance. However, these cells are killed through HBV-induced apoptosis during the antigen-presenting period in HBV-induced chronic liver disease (CLD) patients. Interferon-inducible protein 6 (IFI6) delays type I interferon-induced apoptosis in cells. We hypothesized that single nucleotide polymorphisms (SNPs) in the IFI6 could affect the chronicity of CLD. The present study included a discovery stage, in which 195 CLD patients, including chronic hepatitis B (HEP) and cirrhosis patients and 107 spontaneous recovery (SR) controls, were analyzed. The genotype distributions of rs2808426 (C > T) and rs10902662 (C > T) were significantly different between the SR and HEP groups (odds ratio [OR], 6.60; 95% confidence interval [CI], 1.64 to 26.52, p = 0.008 for both SNPs) and between the SR and CLD groups (OR, 4.38; 95% CI, 1.25 to 15.26; p = 0.021 and OR, 4.12; 95% CI, 1.18 to 14.44; p = 0.027, respectively). The distribution of diplotypes that contained these SNPs was significantly different between the SR and HEP groups (OR, 6.58; 95% CI, 1.63 to 25.59; p = 0.008 and OR, 0.15; 95% CI, 0.04 to 0.61; p = 0.008, respectively) and between the SR and CLD groups (OR, 4.38; 95% CI, 1.25 to 15.26; p = 0.021 and OR, 4.12; 95% CI, 1.18 to 14.44; p = 0.027, respectively). We were unable to replicate the association shown by secondary enrolled samples. A large-scale validation study should be performed to confirm the association between IFI6 and HBV clearance.

• Korean Journal of Plant Tissue Culture
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• v.28 no.6
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• pp.335-339
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• 2001

Grapevine leafroll-associated 3 closterovirus (GLRaV-3) is phloem limited virus, and one of the most severe viral diseases found in Korea. However, nonhomogenous distribution and low concentration and seasonal variations of GLRaV-3 in grapevines remain as main problems which prevent the introduction and molecular biology or serology experiments. Virus-infected plantlet in vitro was obtained from node tissue cuttings, which was GLRaV-3 infected 'kyoho' vines. The amount of purified virus was highest in vitro plantlet. Moreover, viruses seem to be relatively homogeneously distributed in all organs including leaf, stem and callus derived from in vitro plantlets. RT-PCR detection using in vitro plantlet tissue as template was most effective. When comparing ELISA to RT-PCR, RT-PCR detection was 1,000 times as effective as ELISA. These results can be explained by improved quality such as tenderness or less tannins in plantlet in vitro. In conclusion, until infected herbaceous host will be available, tissue culture can be usefully adopted as a technique for a good source of GLRaV-3 closterovirus for further studies.

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.301-318
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• 2007

Marek's disease (MD) is a highly contagious lymphoproliferative disease of poultry caused by the oncogenic herpesvirus designated Marek's disease virus (MDV). MD has a worldwide distribution and is thought to cause an annual loss over US$ one billion to the poultry industry. Originally described as a paralytic disease, today MD is mostly manifested as an acute disease with tumors in multiple visceral organs. MD is controlled essentially by the widespread use of live vaccines administered either in ovo into 18-day-old embryos or into chicks immediately after they hatch. In spite of the success of the vaccines in reducing the losses from the disease in the last 30 years, MDV strains have shown continuous evolution in virulence acquiring the ability to overcome the immune responses induced by the vaccines. During this period, different generations of MD vaccines have been introduced to protect birds from the increasingly virulent MDV strains. However, the virus will be countered each new vaccine strategy with ever more virulent strains. In spite of this concern, currently field problem from MD is likely to be controled by strategy of using bivalent vaccine. But, potential risk factors for outbreak of MD are still remained in this condition. The major factors can be thought that improper handling and incorrect administration of the vaccine, infection prior to establishment of immunity, suppression of immune system by environmental stress and outbreaks of more virulent MDV strain by using vaccine and genetic resistance of host.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.223-231
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• 2005

A quantitative risk assessment tool was used to provide estimates of the probability that foot-and-mouth (FMD) virus-contaminated, smuggled animal products are fed to susceptible swine in Korea. Sensitivity analyses were conducted to attempt to distinguish between parameter uncertainty and variability, using different assumptions on the effect of cooking at home, the effect of the fresh meat, and the effect of heat treatment at garbage processing facility. The median risk estimate was about 20.1% with a mean value of 27.4%. In a scenario regarding all beef and pork were considered as fresh meat the estimated median risk was 3.4%. The risk was greatly dependent on the survival parameters of the FMD virus during the cooking or heat treatment at garbage processing facility. Uncertainty about the proportion of garbage that is likely contaminated with FMD had a major positive influence on the risk, whereas conversion rate representing the size of a load had a major negative effect. This model was very useful in assessing the risk explored. However, the model also requires enhancements, such as the availability of more accurate data to verify the various assumptions considered such as FMD prevalence in a specific country, proportion of garbage which is recycled as feed, proportion of food discarded as garbage. Other factors including the effect of selection of animals for slaughter, ante- and post-mortem inspection, the domestic distribution of the smuggled products, and susceptible animals other than pigs, are need to be taken into account in the future model development.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.859-871
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• 1996

This study was conducted to elucidate the distribution of Aujeszky's disease viral nucleic acids and antigens in the central nervous system (CNS) of piglets. The first Korean isolate of Aujeszky's disease virus(ADV) that isolated from naturally infected piglets in Yang San, was inoculated into 32 day old piglets with $10^{5.9}TCID_{50}/ml$ through intranasal or intramuscular route. These piglets were sacrificed at every 24hrs for 8 days. The immunohistochemistry (IHC) was conducted to detect the viral antigens in paraffin-embedded tissue sections using avidin-biotin-peroxidase complex (ABC) method. The viral nucleic acids were detected by in situ hybridization (ISH) using ADV specific DNA probe labeled with digoxigenin. The ADV antigens were detected in reticuloendothelial cells of spleen, lymph nodes and tonsil, alveolar walls, leptomeningeal vascular walls, inflammatory foci of each organ, and nerve cells. The viral nucleic acids were detected in the spinal trigeminal nucleus and its tracts of the pons and medulla oblongata by the ISH technique. The pathways of AD viruses in CNS were determined by IHC and ISH. In the intranasally inoculated group, the viruses in nasal mucosa moved to medulla oblongata and pons through the trigeminal nerve. In case of intramuscullarly inoculated group, viruses moved to brain via lymphoid organs or spinal nerves from sciatic nerves.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.323-327
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• 2011

Fecal specimens from acute gastroenteritis in Seoul from 2009 to 2010 were collected and then tested for the presence of Group A Rotavirus by ELISA. Among a total of 1,916 samples investigated, 354 samples (18.4%) were positive. The predominant genotypes of positive samples were confirmed as P6G[4] (35%), P8G[3] (28%), P8G[1] (24%), P4G[2] (10%), P8G[9] (3%), respectively. Among a total of 70 ground water samples investigated, 2 samples (2.8%) were positive. The genotypes of positive samples were confirmed as P8G[3] (100%). By this molecular investigation, genotypic distribution associated with rotavirus will be used for control and prevention of rotavirus related diseases.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.619-631
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• 2021

Alfalfa mosaic virus (AMV), an economically important pathogen, is present worldwide with a very wide host range. This work reports for the first time the infection of Vinca minor and Wisteria sinensis with AMV using RNA sequencing and reverse transcription polymerase chain reaction confirmation. De novo assembly and annotating of contigs revealed that RNA1, RNA2, and RNA3 genomic fragments consist of 3,690, 2,636, and 2,057 nucleotides (nt) for IR-VM and 3,690, 2,594, and 2,057 nt for IR-WS. RNA1 and RNA3 segments of IR-VM and IR-WS closely resembled those of the Chinese isolate HZ, with 99.23-99.26% and 98.04-98.09% nt identity, respectively. Their RNA2 resembled that of Canadian isolate CaM and American isolate OH-2-2017, with 97.96-98.07% nt identity. The P2 gene revealed more nucleotide diversity compared with other genes. Genes in the AMV genome were under dominant negative selection during evolution, and the P1 and coat protein (CP) proteins were subject to the strongest and weakest purifying selection, respectively. In the population genetic analysis based on the CP gene sequences, all 107 AMV isolates fell into two main clades (A, B) and isolates of clade A were further divided into three groups with significant subpopulation differentiation. The results indicated moderate genetic variation within and no clear geographic or genetic structure between the studied populations, implying moderate gene flow can play an important role in differentiation and distribution of genetic diversity among populations. Several factors have shaped the genetic structure and diversity of AMV: selection, recombination/reassortment, gene flow, and random processes such as founder effects.

• Journal of Ecology and Environment
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• v.46 no.1
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• pp.54-61
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• 2022

Background: In South Korea, African swine fever virus (ASFV) has spread among wild boars through Gangwon-do to Dangyang-gun, Chungcheongbuk-do on the southern border of Gangwon-do. To prevent the spread of ASFV to African swine fever (ASF)-free areas, it is necessary to identify areas with a high probability of finding ASFV-infected carcasses and to reduce the density of wild boars in those areas. In this study, we described the propagation trend of ASFV among wild boars, constructed the habitat suitability maps for ASFV-infected carcasses, and suggested areas with a high probability of finding ASFV-infected carcasses and an important route of ASFV transmission. Results: Despite the active quarantine policies in Korea to prevent the spread of ASFV through wild boars, there was no significant difference in the monthly average of number of ASFV-infected carcasses observed between 2020 and 2021. The ASFV-infected carcasses were found more in winter and spring (January to April). Since the first ASF outbreak in wild boars on October 2, 2019, the maximum width of ASFV-infected carcass distribution area was 222.7 km for about 26 months till November 20, 2021. The habitat suitability map, based on GPS coordinates of ASFV-infected wild boar carcasses, shows that highly detectable areas of ASFV-infected carcasses were sporadically dispersed in western and southwestern parts of Gangwon-do, and ranged from north to south of the province along the Baekdudaegan Mountains, whereas poorly detectable areas ranged along the north to the south in the middle parts of the province. Conclusions: Our suitability model, based on the GPS coordinates of ASFV-infected carcasses, identifies potential habitats where ASFV-infected carcasses are likely to be found and ponential routes where ASFV is likely to spread. Among ASF-free areas, the areas with high suitability predicted in this study should be given priority as survey areas to find ASFV-infected carcasses and hunting areas to reduce wild boar populations.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.37-40
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• 2012

The burden of cervical cancer is increasing in Vietnam in the recent years, infection with high risk HPV being the cause. This study aimed to examine the prevalence of HPV and the distribution of HPV specific types among the general population in 5 big cities in Vietnam. Totals of 1500 women in round 1 and 3000 in round 2 were interviewed and underwent gynecological examination. HPV infection status, and HPV genotyping test were perfoirmed for all participants. Results indicated that the prevalence of HPV infection in 5 cities ranged from 6.1% to 10.2% with Can Tho having highest prevalence. The most common HPV types in all 5 cities were HPV 16, 18 and 58. Most of the positive cases were infected with high risk HPV, especially in Hanoi and Can Tho where more than 90% positive cases were high risk HPV. Furthermore, in Can Tho more than 60% of women were infected with multiple HPV types. The information from this study can be used to provide updated data for planning preventive activities for cervical cancer in the studied cities.

• Journal of Life Science
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• v.8 no.3
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• pp.279-284
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• 1998

The nucleotide sequences of the 5'-untraslated region(5'-UTR) of Hepatitis G virus(HGV) from sera of Korean patients were determines. When compared to the previously reported isolates, the Korean isolates have higher sequence homology with the Japanese isolates indicating the geographic distribution of HGV variants. Interestingly, three discrete regions which are highly conserved among HGV isolates from the same geographical area, thus could be applied to distinguish HGV isolates from the different areas were noticed in the 5'-UTR. Based on the sequences of these group-specific regions, twenty four different HGV isolates could be classified into 5 groups. By using the group-specific regions, inconsistency in HGV typing when based on the different regions of HGV could be solved.