• 대한바이러스학회지
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• 제28권2호
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• pp.175-182
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• 1998

We investigated the rate of hepatitis G virus infection among 50 patients who were not infected with the hepatitis C virus but showed symptoms of hepatitis. Viral RNA was extracted from the patients' sera and cDNA was synthesized and amplified by RT-PCR (reverse transcription-polymerase chain reaction) using random hexamer and 5 primers (470-20-1-77F, 470-20-1-211R, 470-20-1-211R-biotin, GV57-4512MF, GV57-4657MR). The amplified PCR products were confirmed by electrochemiluminescence (ECL), liquid hybridization (LH) and Southern blotting (SB). Among the 50 PCR products, by means of ECL, we found 4 samples to be positive and 5 samples to be indeterminate. The GV45-89M probe (5'-CYCGCTGRTITGGGGTGTACfGGAAGGC-3') was end-labelled with gamma-$^{32}P$ ATP and used for liquid hybridization with the PCR products. By using liquid hybridization, we detected specific bands from 4 positive sera and also from one indeterminate serum as determined by ECL. An 1.5% agarose gel electrophoresis of the 9 PCR products which were HGV positive or indeterminate as determined by ECL showed a 160bp band from 4 positive and one indeterminate serum. The 5 PCR products proved to be positive when SB was applied with the GV45-89M probe as well as when LH was applied. LH and SB were shown to have higher sensitivity and specificity than ECL. Two cases among 5 positive cases had relatively high SGOT, SGPT, ALP values when compared with other 48 cases. In summary, we confirmed hepatitis G virus infection in 5 cases among 50 Korean patients showing symptoms of viral hepatitis.

• 한국연초학회지
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• 제15권1호
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• pp.15-25
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• 1993

The severities of major tobacco diseases had been surveyed throughout northern Kyeongbuk, a major flue-cured tobacco growing district in Korea, in relation to the actual control method used by the farmers in 1992. At seedling stage, anthracnose caused by Colletotrichum nicotianae was major disease of the plant due to poor damage of the temporary transplanting pots. Mosaic caused by tobacco mosaic virus(TMV) was very severe in certain of greenhouses. Although viral disease caused by TMV, cucumber mosaic virus(CMV) and by potato virus Y(PVY) were severe in fields, but mosaic by TMV was major of the diseases. Potato virus Y was found later than that in Honam district. The late occurrence of the disease might be caused the difference between cultivating method of potato plants in northern Kyeongbuk and that in Honam district. In fields suffered from hail disaster, the damage of tobacco plants by angular leaf spot was severe. Most of tobacco growers had wrong information about the practical methods not only of milk treatment for the protection of the plants from TMV, but also of fungicide applications for the control of other major diseases. It suggested that education on the methods to the farmers must be very important for control of the diseases.

• 한국응용곤충학회지
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• 제15권3호
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• pp.137-145
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• 1976

우리나라에서의 바이러스 무감염란 생산에 필요한 기초자료를 얻기 위하여 Cymbidiun mosaic virus와 Tobacco mosaic virus를 중심으로 그 감염상 및 감염된 바이러스의 혈청학적 반응, 검정식물상의 반응, 물이적 성질, 형태등을 조사하여 다음과 같은 결과를 얻었다. 1. 란에 발생하는 바이러스병의 병징은 크게 1) 모자이크, 2) 괴저줄무늬 모자이크, 3) 괴원륜문, 4) 퇴록륜문 및 5) 괴달반점의 5군으로 분류되었다. 2. 수원근교의 난 재배농장에서 수집한 각종란의 바이러스 이병률을 조사한 결과 CyMV는 $45\%$의 감염율을 나타내었고, TMV는 한개체에서도 검출되지 않았다. 3. CyMV의 검정식물인 Chenopodium amaranticolor, Cassia occidentalis 및 Datura stramonium에 CyMV 병즙액을 접종한지 7-12일 후에 퇴록국부반점이 나타났다. 4. CyMV의 물리적 성질을 Chenopodium amaranticolor를 검정식물로 하여 조사한 결과, 내열성은$75-80^{\circ}C$ 내보존성은 8일, 내포석성은 $10^{-5}-10^{-6}$으로 나타났다. 5. CyMV의 혈정학적 한천내 확산반응에 사용된 0.1M 및 0.01M의 Phosphate, Imidazol 및 Tris 완충간에는 침강대 형성에 차이를 볼 수 없었다. 그러나 이들 완충액의 수소이온농도간에는 침강대 형성에 심한 차이를 나타내어, pH 7.0에서는 침강대가 뚜렷하였고 pH9.0에서는 미약하였다. 6. CyMV를 전자현미경으로 관찰한 결과 크기 460-580mu의 간상입자의 빈도가 제일 높았다.

• IMMUNE NETWORK
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• 제10권4호
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• pp.120-125
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• 2010

Dysfunction of the virus-specific T cells is a cardinal feature in chronic persistent viral infections such as one caused by hepatitis C virus (HCV). In chronic HCV infection, virus-specific dysfunctional CD8 T cells often overexpress various inhibitory receptors. Programmed cell death 1 (PD-1) was the first among these inhibitory receptors that were identified to be overexpressed in functionally impaired T cells. The roles of other inhibitory receptors such as cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and T cell immunoglobulin and mucin domain-containing molecule 3 (Tim-3) have also been demonstrated in T-cell dysfunctions that occur in chronic HCV patients. Blocking these inhibitory receptors in vitro restores the functions of HCV-specific CD8 T cells and allows enhanced proliferation, cytolytic activity and cytokine production. Therefore, the blockade of the inhibitory receptors is considered as a novel strategy for the treatment of chronic HCV infection.

• 대한수의학회지
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• 제55권1호
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• pp.53-56
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• 2015

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis. This study was conducted to clarify the molecular characteristics of BLVs obtained from a specific region in Korea. Proviral BLVs were detected in anti-BLV antibody-positive blood samples by PCR. Env and gag fragments were sequenced and compared to previously published reference sequences. Analysis of the env gene sequence revealed that the YI strain was highly similar to genotype 1, including United States and Japanese strains. The gag gene sequence had the highest degree of similarity with a Japanese strain.

• 식물병연구
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• 제8권2호
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• pp.78-83
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• 2002

Tobacco diseases have not been recorded until 1900s in Korea, where tobacco plants were introduced at early 1700s. Practical researches on the disease have been conducted since mid 1960s. Major ten tobacco diseases were mosaic caused by tobacco mosaic virus·potato virus Y·cucumber mosaic virus, bacterial wilt, hollow stalk, wild fire caused by angular leaf spot strain, black shank, brown spot, powdery mildew and fusarium wilt. But their annual occurrences were varied according to changes of tobacco varieties and their cultivating practices. As no useful chemicals, several biological tactics have been developed to control the viral or bacterial diseases that give significant economic damages on sustainable crop yield, but not practicable to field farming condition yet. Transgenic tobacco plants containing foreign disease resistant genes have been developed by current bio-technology, but not released to farmers yet. Though some disease-resistant tobacco varieties have been developed by the conventional breeding technology and currently used by farmers, their disease controlling efficacy have been diminished by occurrence of the new strain or race. Future research on tobacco diseases has been focused on technical development to produce high quality tobacco with less production cost, which leads Korean tobacco industry to keep its competence against foreign industry and decreasing overall market.

• 대한바이러스학회지
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• 제29권4호
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• pp.221-233
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• 1999

Prospect Hill Virus (PHV) is the well known serotype of hantavirus, a newly established genus in family Bunyaviridae. Extensive studies have upheld the original view of PHV genetics with three genes such as nucleocapsid (N) protein, envelope proteins (G1, G2) and RNA dependent RNA polymerase. In this study, we report the existence of additional gene that is encoded in an overlapping reading frame of the N protein gene within S genome segment of PHV. This gene is expected to encode a nonstructural small (NSs) protein and it seems to be only found in PHV infected cell. The presence and synthesis of NSs protein could be demonstrated in the cell infected with PHV using anti-peptide sera specific to the predicted amino acid sequence deduced from the second open reading frame. Ribosomal synthesis of this protein appears to occur at AUG codon at the 83rd base of S genome segment, downstream of N protein initiation codon. This protein is small in size (10.4 KDa) and highly basic in nature. The expression strategy of NSs protein appears that a signal mRNA is used to translate both N and NSs protein in PHV infected cell. 10 KDa protein in virus infected cell lysates can bind to mimic dsRNA. This fact strongly suggests that NSs protein may be involved in virus replication on late phase of viral life cycle.

• 대한바이러스학회지
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• 제30권1호
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• pp.19-28
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• 2000

Two distinct hantaviruses have been isolated from Apodemus agrarius in 1976 and Rattus norvegicus in 1980 in Korea. Since our serosurveys conducted in 1994, a genetically distinct hantavirus from Apodemus peninsulae has been investigated. To isolate hantavirus from Apen insulae captured in Korea, the lung homogenate of seropositive Apeninsulae inoculated Vero E6 cells. Viral antigen was detected in a progressively higher percentage of cells with subsequent passage after 80 days postinoculation. The new isolate from seropositive Apodemus peninsulae was designated Suchong virus after Suchong valley located in northeastern region of South Korea. Comparing with hantaan virus 76-118 strain, Suchong virus-1, 2, 3 and 4 showed the similarity of $71.0{\sim}91.8%$ at nucleotide and $90.9{\sim}94.8%$ at amino acid sequences in 231 nucleotides region of M segment, and the similarity of $75.1{\sim}81.0%$ at nucleotide and $97.5{\sim}100%$ at amino acid sequences in 237 nucleotides of S segment.

• 한국동물위생학회지
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• 제24권3호
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• pp.223-241
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• 2001

From September 1996 to September 1999, 419 Korean-native calves with diseases under 6-month old collected from Kyonggi, Chungcheong, Chonlla and Kyongsang were examined by clinical, microbiological, parasitic, hematologic and histopathological mean. Among them, 124 cases were tested about the neutralization antibodies against infectious bovine rhinotracheitis virus(IBRV), Parainfluenza-3 virus(PI-3V), bovine uiral diarrhea virus(BVDV), bovine ephemeral fever virus(BEFV). In calf diseases in the survey, enteric diseases(72.8%) were most frequently involved and the following orders were taken by respiratory(17.4%) and reproductive (5.0%) disorders. In the causative pathogens associated with calf diseases and motality, 48.4% was induced by bacteria origin and also 35.6% by viral agents. Calf mortality was up to 76.3% in the cae of bacterial diseases and 55.7% in viral diseases. In bacterial diseases, frequent disorders were composed of colibacillosis(52.7%), salmonellosis(13.8%), pasteurellosis(12.8%) and campylobacteriosis(3.9%) and their mortalities showed 73.8% in colibacillosis, 73.0% in pasteurellosis, 67.9% in salmonellosis and 50.0% in campylobacteriosis (50.0%). Among the outbreaks of viral diseases, there were BVD(22.8%), bovine rotavirus infection(20.8%), bovine coronavirus infection(16.8%), bovine respiratory syncytial virus infection(15.4%), IBR(15.4%). Akabane disease(4.7%) and Chuzan diseases(3.4%). Interesting results through this studies were obtained the first isolate to Chuzan virus and Ainovirus in Korea which could be promised the development for diagnostic method and vaccines soon. Calf mortality to Akabane and Chuzan diseases was 100%. Main parasitic diseases were occupied by coccidiosis and babesiosis and their mortality of babesiosis was 20.0%. Other diseases were abomasal impaction(6.7%) and toxicosis(4.5%). The mortality of abomasal impaction was 89.3%. In some causes with malformations(1.9%) were confirmed as anasarca, derodidymus, polymelia, humerus hypoplasia, and tracheal collapse. Calf diseases had mostly been occurred in one month old grout (52.5%) and its prevalence was 25.1% in two to three month old group and 22.4% in four to six month old group. In calf mortality by age, there were 37.9% in one month old group, 18.1% in two and three month old group, and 13.8% in four to six month old group, respectively. The older the age of calf, the less the prevalence of calf enteric diseases. Respiratory diseases in calves to be tested frequently occurred in one to two month old group (41.4%). In one month old calves, the prevalence of enteric disease was 80.0%(p<0.05) and that of reproductive and respiratory disease was 9.5% and 8.2%, respectively. In two month old and four to six month old, enteric disease was 65.7% and 63.8% and respiratory disease was 28.6% and 26.6%. Seasonal prevalence and mortality of Korean-native calf diseases were not a significant difference. Prevalence of calf diseases in summer(31.5%) frequently occurred to compare that in winter(20.3%). Abortion and malformation in calves frequently occurred in spring. Hematological values in 84 calves with clinical signs showed mild to marked leukocytosis. Also, there was slight increase in hematocrit, platelet, mean corpuscular volume and mean plasma volume, but all of those were included the higher level to normal ranges. Calves with respiratory signs showed slightly erythrocytosis. One hundred seventy three calves without clinical signs were not significant different to ill cases in hematological values, but number of platelets was in higher normal range. In 125 calves, 84.8% was taken the antibody to IBRV, but 72% with the antibody had recorded the titer level lower than log$_2$5. The neutralizing antibody levels of higher than $log_{2}5$ to PI-3V and BVD virus were 60.8% and 67.2% cases, respectively. There were the cases of 57.6% had the neutralizing antibody level lower than log$_2$5 to BEFV.

• Biomolecules & Therapeutics
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• 제29권3호
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• pp.249-262
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• 2021

The most effective way to control newly emerging infectious disease, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, is to strengthen preventative or therapeutic public health strategies before the infection spreads worldwide. However, global health systems remain at the early stages in anticipating effective therapeutics or vaccines to combat the SARS-CoV-2 pandemic. While maintaining social distance is the most crucial metric to avoid spreading the virus, symptomatic therapy given to patients on the clinical manifestations helps save lives. The molecular properties of SARS-CoV-2 infection have been quickly elucidated, paving the way to therapeutics, vaccine development, and other medical interventions. Despite this progress, the detailed biomolecular mechanism of SARS-CoV-2 infection remains elusive. Given virus invasion of cells is a determining factor for virulence, understanding the viral entry process can be a mainstay in controlling newly emerged viruses. Since viral entry is mediated by selective cellular proteases or proteins associated with receptors, identification and functional analysis of these proteins could provide a way to disrupt virus propagation. This review comprehensively discusses cellular machinery necessary for SARS-CoV-2 infection. Understanding multifactorial traits of the virus entry will provide a substantial guide to facilitate antiviral drug development.