• The Korean Journal of Cytopathology
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• v.15 no.1
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• pp.17-27
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• 2004

To investigate a population-based survey of the prevalence of human papillomavirus (HPV) infection in South Korea, we performed Papanicolaou smears and tests for HPV DNA and anti-HPV antibody detection in 909 sexually active general women (age range; 20-74 years, median 44 years) who were randomly selected residents from S district of Busan City. The presence of DNA of 36 different HPV types was detected by means of a GP 5+/6+ primer-mediated PCR enzyme immunoassay in cervical exfoliated cells, and IgG antibodies against L1 virus-like particles (anti-VLPs) of 5 HPV types 16, 18, 31, 33, and 58 were tested by means of enzyme linked immunoassay. The incidence of cytologic abnormality was 5.2% in Pap smear. The positive rate of HPV DNA was 10.4%, high in young women younger than 35 years old and proportionally increased according to the cytologic grades. The most often found HPV type was HPV 70, followed by HPV 16 and 33, and high-risk HPV types were more frequent in women younger than 35 years old. The most common HPV type in abnormal cytologic smears was HPV 16, followed by HPV 58 and 66. Anti-VLPs was positive in 19.7% and the frequent anti-VLPs type was against HPV 18, followed by HPV 31 and 16. The concordance between the markers for each specific HPV type was noted in 10 women and HPV 16 was the most frequent one. The incidence of multiple HPV infection was 18.9% and that of multiple anti-VLPs antibodies was 31%. Among 103 self-reported virgins, 4.9% had anti-VLP antibodies.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.235-238
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• 2016

Hepatitis C is an ailment of liver caused by hepatitis C virus (HCV) infection. About 3% of the world population is infected by this virus. HCV infection is a leading reason for liver cirrhosis and therefore a major source of hepatocellular carcinoma. The study focused on the incidence of active HCV infection in blood donors of Mardan district of KPK, Pakistan. A total of 5318 blood donors were inspected for the presence of anti-HCV antibodies and HCV-RNA using ICT (immune-chromatographic test), ELISA and RT-PCR at Mardan Medical Complex (MMC), Mardan. Out of these, 157 (2.95%) were positive by ICT, 60 (1.12%) by ELISA and 56 (1.05%) for HCV-RNA. The frequency of active HCV infectivity amongst the blood donors from district Mardan, KPK Pakistan was 1.05 %. Application of strict measures during blood donor selection and use of proper screening assays such as ELISA in place of ICT devices can give a more accurate picture so that the incidence of this viral infection in HCV negative blood recipients can be reduced.

• Research in Plant Disease
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• v.12 no.1
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• pp.28-31
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• 2006

One of major potato viruses is Potato virus Y (PVY) in Korea. In the southern part of Korea, potatoes have been grown as double crops in a year by using cv. 'Dejima' and 'Chubak' due to very short dormancy. However, they have caused a serious problem such as a rapid degeneration. It has been thought that the degeneration is affected by the high incidence of PVY in neighboring potato fields. Therefore, the investigation of factors causing the degeneration is very important in the production of healthy seed potato. In this study, the PVY reinfection rates of several potato varieties and the different seed sources of cv. 'Chubak' have been investigated. Results show that the lowest infection rate of PVY among four potato cultivars derived from minitubers is cv. 'Superior'. The others are in order of 'Dejima', 'Atlantic' and 'Chubak'. Also, the incidences of PVY differ significantly when several seed sources are examined. When the seed potatoes (G2, the progeny of microtuber) as spring potato crops are planted in area without potato field nearby, the infection rate of PVY is as low as that of microtubers. However, PVY incidence in the progenies of minitubers as fall potato crops largely increases. Therefore, the best way of potato production under double cropping system is to use the healthy seed potato produced in area without potato field and plant relatively resistant cultivar such as Dejima.

• Korean journal of applied entomology
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• v.20 no.3 s.48
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• pp.135-145
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• 1981

Vegetables including Chinese cabbage and radish have been grown in alpine areas such as Muju, Namweon, Jinan and Jangsu during the shortage period of vegetables. The incidence of various diseases, environmental factors such as temperatures and rainfalls, and aphid populations as virus vector were observed at 10-day intervals from July to September in those areas. Disease incidence showed no significant difference among locations. Major diseases in Chin ese cabbage were bacterial soft rot, white spot, downy mildew, mosaic virus, Alternaria leaf spot and Fusarium seedling blight. Major diseases in radish were virus, white rust, black rot, root rot, leaf spot and Fusarium seedling blight. Disease incidence reached peak on Aug. 20 with $27\%$ infection in radish and with $20\%$ infection in Chinese cabbage during the growing season, and declined thereafter. Percentage of infection in each growth stage showed $25\%$ at root thickening stage and $26\%$ at the harvest time in radish; and the head formation stage, $24\%$ at the harvest time. The data indicate that disease incidence in radish increased rapidly at late growing stage and progressively increased in Chinese cabbage Seedling blight caused by Fusarium sp. and root rot caused by Aphanomyces sp. were also observed in those areas. Cool and wet weather appeared to be favorable for disease incidences during the rainy period of growing season although average temperature was about $25^{\circ}C$. Populations of aphids were lower in the alpine vegetable growing area than that of flat areas. Aphids as virus vectors from total aphids collected were $73.5\%$ or 289 virus vectors /993 total aphids in Namweon and $18.1\%$ or 31 virus vectors/171 total aphids in Muju. The most prerevalent species of aphids was Myzus persicae Sulz.

• Research in Plant Disease
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• v.24 no.2
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• pp.145-152
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• 2018

During 2015-2017, we surveyed the incidence of viral infections of tomato and paprika growing in greenhouses in Cherwon province, Korea. In 2015 and 2016, we collected leaves and fruits from tomato and paprika plants growing in greenhouses. We detected viruses in the samples collected using specific primer sets for Broad bean wilt virus 2 (BBWV2), Cucumber mosaic virus (CMV), Pepper mild mottle virus (PMMoV), Pepper mottle mosaic virus (PepMoV), and Tomato spotted wilt virus (TSWV). We detected PMMoV, CMV, and TSWV in the samples, and CMV and TSWV were the most prevalent. For the prevention of future viral diseases, we then surveyed the routes of infection by these viruses in tomato and paprika plants growing in greenhouses in Cherwon province in 2017. Leaf and fruit samples were collected from seedlings and crops two and four months after transplanting into greenhouses. As a result, we found that TSWV was transferred from seedlings to plants, and outbreaks of the virus occurred at the early stage of cultivation. On the other hand, we found that CMV was a virus indigenous to the soil of some towns in Cherwon province, and thus outbreaks of this virus occurred at the middle stage of cultivation.

• Korean journal of applied entomology
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• v.14 no.2 s.23
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• pp.59-63
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• 1975

A total of 40 virus infected tobacco plants (Nicotiana tabaccum L.) with various symptom types Were collected from Bucheon and Jeonju area by its symptoms were investigated on the incidence of tobacco mosaic virus (TMV), cucumber mosaic virus (CMV), alfalfa mosaic virus (AMV), potato virus X (PVX) and potato virus Y (PVY) by serological methods. van Slogteren's microprecipitin test was applied for the testing of PVX and PVY from infected plants and Ouchterlony agar double diffusion test was used for CMV, TMV and AMV. Results obtained are as follows: 1. TMV, CMV, AMV, PVX and PVY wcre found to occur on the tobacco plants growing in Korea. 2. The prevalence of each of these viruses among the 40 tobacco plants investigated was in the order of AMV: $(67.5\%)>CMV:(60.0\%)>TMY:(47.5\%)>PVY:(17.5\%)>PVX: (10.0\%).$ 3. In Burley variety, the percentage of infection by TMV was $15\%$, whereas it was as high as $80\%$ in Hicks variety. 4. Among the 40 tobacco plants investigated, $37.5\%$ showed infection with one kind of virus whereas the remaining $62.5\%$, revealed mixed infection with more than two different viruses.

• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.37-37
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• 2015

dsRNA was found in malformed cultures of Lentinula edodes strain FMRI0339, one of the three most popular sawdust cultivated commercial strains of shiitake, and was also found in healthy-looking fruiting bodies and actively growing mycelia. Cloning of the partial genome of the dsRNA revealed the presence of the RdRp sequence of a novel L. edodes mycovirus (LeV), and sequence comparison of the cloned amplicon showed an identical sequence to known RdRp genes of LeV found in strain HKA. The meiotic stability of dsRNA was examined by measuring the ratio of the presence of dsRNA among sexual monokaryotic progeny. More than 40% of the monokaryotic progeny still contained the dsRNA, indicating the persistence of dsRNA during sexual reproduction. Comparing the mycelia growth of monokaryotic progeny suggested that, although variations in the growth rate existed among progeny and virus infection was observed in highly actively growing progeny, there appeared to be a tendency toward a lower frequency of virus incidence in actively growing progeny. This study attempted to cure the edible mushroom L. edodes strain FMRI0339 of the L. edodes mycovirus (LeV) in order to obtain an isogenic virus-free fungal strain as well as a virus-infected strain for comparison. Mycelial fragmentation, followed by being spread on a plate with serial dilutions resulted in a virus-free colony. Viral absence was confirmed with gel electrophoresis after dsRNA-specific virus purification, Northern blot analysis, and PCR using reverse transcriptase (RT-PCR). Once cured, all of fungal cultures remained virus-free over the next two years. Interestingly, the viral titer of LeV varied depending on the culture condition. The titer from the plate culture showed at least a 20-fold higher concentration than that grown in the liquid culture. However, the reduced virus titer in the liquid culture was recovered by transferring the mycelia to a plate containing the same medium. In addition, oxygen-depleted culture conditions resulted in a significant decrease of viral concentration, but not to the extent seen in the submerged liquid culture. Although no $discernable phenotypic changes in colony morphology were observed, virus-cured strains showed significantly higher growth rates and mycelial mass than virus-infected strains. We were also explored effects of LeV on fruiting body formation and mushroom yield. The fruiting body formation yield of virus-free L. edodes was larger than virus-infected L. edodes. These results indicate that LeV infection has a deleterious effect on mycelial growth and fruiting body formation. In addition, we have been investigated host-parasite interaction between L. edodes and its mycovirus interaction to study viral mechanism by establishment of proteomics.

• Research in Plant Disease
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• v.10 no.4
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• pp.231-240
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• 2004

In the year of 2002 annual nationwide survey of virus diseases occurring in the pepper fields and greenhouses in Korea, the distribution and the incidence of viral diseases was investigated. The pepper samples from both greenhouses (155 samples) and open fields (227 samples) were collected and further analyzed to detect eleven different viruses by RT-PCR. The results indicate that no sample collected from both greenhouse and open field seems to be infected by TMV, RMV, PVY, AMV, and TSWV. On the other hand, CMV, BBWV2, PepMoV, PMMoV, TMGMV and ToMV are readily identified from greenhouse and open field samples by RT-PCR. The infection rates of the collected samples between greenhouse and open field are largely different. Comparing with 10% of virus-infected pepper samples grown in greenhouse, approximately one third of pepper samples collected from open field are infected. The mixed-infection rates in the virus-infected greenhouse and open field samples are 16% and 61%, respectively. The dominant virus occuring in greenhouse is PMMoV, indicating that virus-infected seed stocks and infected plant debris in the growing area may be important sources of inocula. On the other hand, both CMV and BBWV2 are dominant viruses in open field. This may indicate that the migration of viruliferous insect vectors into pepper fields may be the most important source of inoculum. Also, the survey shows that BBWV2 is newly immerging virus to be controlled in Korea. The discrepancies on the distribution and the occurrence of viral diseases between field and greenhouse may provide a fact that the accumulation and distribution of inoculum by successive cultivation and the migration of viruliferous vectors into growing areas are likely to be important factors to determine the incidence of viral diseases. Therefore, the further studies on epidemiology and the consideration of new breeding program of pepper are essential to minimize virus diseases.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.91-98
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• 1989

The effects of the serum total protein and immunoglobulin levels of the colostrumconferred Korean native calves at 2 days of age on the disease incidence during the suckling period were studied. The results obtained were summerized as follows: 1. Serum total protein, total immunoglobulin, IgG, and IgM levels of 6 Korean native claves died from septicemia were lower than those of calves survived (p<0.05). 2. Korean native calves having low serum total protein and immunoglobulins were affected with diarrhea earlier in life, when compared with calves having high serum levels (p<0.05). 3. Korea native calves having low serum total protein were affected with bronchopneumonia earlier in life, when compared with calves having high serum levels (p<0.05). 4. Korean native calves having low serum neutralizing antibody titers to bovine viral diarrhea virus had high incidence rate of BVD, when compared with calves having high serum neutralizing antibody titers (p<0.05).

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.35-40
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• 2004

Bombyx mori densonucleosis virus type 1 (BmDNV1)- a non occluded virus causes flacherie disease in the susceptible stocks of the silkworm, Bombyx mori. However, some stocks are non-susceptible. Non-susceptibility to BmDNV1 in B. mori is a unique case where the virus infection is completely inhibited by a single gene of the host. A survey conducted by this institute in some parts of Karnataka state has revealed that, 43.05% of the total incidence of flacherie disease caused by non-occluded viruses, are due to the synergistic infection of B. mori densonucleosis and infectious flacherie virus. Earlier study indicated that rearing of BmDNV1 resistant silkworm stock is effective in protecting silkworm against BmIFV also. In the present study the response of 78 silkworm stocks which include 42 of non-diapausing and 36 of diapausing groups, to BmDNV1 is investigated. Newly ecdysed third instar larvae were inoculated per-os with 10% inoculum of BmDNV1 extracted from the mid-gut of infected silkworm. One non-diapausing and three diapausing silkworm stocks were found to be resistant to BmDNV1. Eleven silkworm stocks were found to possess moderate resistance whereas rest sixty three were found to be susceptible to BmDNV1. Genetic analysis has shown that the resistance to BmDNV1 is autosomally inherited and controlled by a major dominant or a major recessive gene in different silkworm stocks. These resistant stocks can be utilized as the resource material to develop BmDNV1 resistant commercial hybrids. The selection strategies, depending upon the mode of inheritance of resistance in the resource material chosen, are discussed.