• Journal of fish pathology
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• v.31 no.1
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• pp.9-13
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• 2018

We previously monitored nervous necrosis virus (NNV) in brain samples of artificially produced walleye Pollock (Gadus chalcogrammus) seedlings, with a low prevalence (1.8%, 1/55) but no clinical symptoms. Given that this virus is considered one of the most serious viral threats for almost all marine aquaculture fish species and characterized by both vertical and horizontal transmission, it would be interesting to monitor NNV in the fertilized eggs as well. We collected fertilized walleye pollock eggs from the farms located in Goseong during January to March, 2017. Approximately 50 mg of eggs were periodically taken from 4 each different batches, and 37 different pooled sample sets in total were made during sampling period. RNA was extracted from the eggs by using Trizol and cDNA was synthesized for RT-PCR for detecting NNV. Primers and PCR conditions are the same as previously described. As a result, NNV was not detected from any of the sample sets by one step PCR (0%, 0/37), suggesting NNV may not be a threat in walleye pollock aquaculture in Korea at present time. However, continuous monitoring for NNV should be conducted because introducing a new species into aquaculture industry involves potentials of disease outbreak and NNV is already known to cause outbreaks in gadoid fishes.

• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.156-165
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• 2001

Exogeneous application of pokeweed antiviral protein (PAP), a ribosomal-inacivating protein in the cell wall of Phytolacca americana (pokeweed) protects heterologous plants from viral and fungal infection. A cDNA clone of PAP introduced into Scrophularia buergeriana Miquel by thransformation with Agrobacterium tumefaciences. For plant transformation, explants were precultured on shoot induction medium without kanamycin for 2-5 day, and then they were cocultured with Agrobacterium for 10 minutes. The explants were placed on co culture medium in dark condition, $28^{\circ}C$ for 2days. After explants were washed in MS liquid medium, they were transferred into selection medium including kanamycin 50mg/L (MS salts+1mg/ l BAP+2mg/ l TDZ+0,2mg/ l NAA+MS vitamin+3% sucrose+0.8% agar, pH5.8). From PCR analysis, NPT II band was confirmed in transgenic plant genome and showed resistance against fungi in antifungal activity test. Micro assay to which protein extracted from transgenic line were added, revealed hyphae growth inhibition and no spore germination at high concentration. The characteristics of inhibited hyphae was represented transparent and thin. Expression of PAP in transgenic plants offers the possibility of developing resistance to viral and fungal infection.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.130-136
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• 2008

Purpose: Lamivudine is known to be effective for the treatment of chronic hepatitis B in adults. However, data on lamivudine therapy in pediatrics is limited. The aim of this study was to evaluate the efficacy and durability of lamivudine therapy for chronic hepatitis B in Korean children. Methods: A total of 44 children (27 males and 17 females, ages 6 months to 14.8 years, mean age 6.7 years) with chronic hepatitis B who received lamivudine (3 mg/kg/day, max 100 mg) for at least 12 months were enrolled. We evaluated the serum AST, ALT and serological HBV markers (HBsAg and anti-HBs, HBeAg and anti HBe, and HBV DNA) periodically. Predictive three year cumulative seroconversion rates were obtained using the Kaplan-Meier method. Results: Twenty one (48%) of 44 children achieved seroconversion of HBeAg by three years, while 23 (42%) children did not. HBV DNA was cleared in 34 (77%) children and the serum ALT levels were normalized in 41 children (93%). The three year cumulative seroconversion rates were 60% for HBeAg, and the clearance rates were 76% for HBV DNA. Eighteen children who discontinued lamivudine after HBeAg seroconversion maintained the therapeutic response for three years (treatment duration 13~58 months mean 24 months). Viral breakthrough developed in 12 children (27%) during the therapy and the YMDD mutation was documented in 11 children (25%). The mean duration for the development of a mutation was 22.7 months. Loss of HBsAg occurred in 6 children (14%). The pretreatment ALT levels were higher in responders; however, the differences were not statistically significant (p>0.05). Conclusion: The results of this study showed that lamivudine treatment had a favorable effect and durable therapeutic response in children with chronic hepatitis B. Long term follow-up and alternative therapy are warranted for those patients who do not respond to this treatment.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.140-147
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• 2010

Japanese encephalitis virus (JEV), a member of the mosquito-borne flaviviruses, causes epidemics of viral encephalitis in the Southeastern Asia. JEV is a small enveloped virus with a positive-sense RNA genome; the infectious virion consists of three structural proteins, namely capsid, membrane (M; a mature form of its prM precursor), and envelope proteins. Here, we investigated a role of the charged residues found at the N-terminus of the JEV M protein in virus production. Using an infectious JEV cDNA, we generated two mutant cDNAs, Mm1 and Mm2, by charged-to-alanine substitution for $E^9$ and $K^{15}K^{16}E^{17}$ residues of the M protein, respectively. By transfection of wild-type or each of the two mutant RNAs transcribed from the corresponding cDNAs, we found that Mm2, but not Mm1, had a ~3-log decrease in virus production, even though a comparable amount of all three structural proteins were produced in transfected cells. Interestingly, the prM protein expressed in Mm2 RNA-transfected cells was not recognized by the polyclonal antiserum raised against the N-terminal 44 amino acids of the wild type M protein, but reacted to the antiserum raised against the corresponding region of the mutant Mm2. Our results indicate that three charged residues ($K^{15}K^{16}E^{17}$) in JEV M protein play a role in virus production. Two polyclonal antisera specifically recognizing the wild-type or Mm2 version of the M protein would provide a useful reagent for the functional study of this protein in the virus life cycle.

• Pediatric Infection and Vaccine
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• v.12 no.2
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• pp.166-177
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• 2005

Purpose : The purpose of this study was to examine the molecular epidemiology and genetic variability of adenovirus(Ad) serotypes Ad1, Ad2, and Ad5 over 14 years in Korea. Methods : A total of 382 adenoviral strains isolated from the nasopharyngeal aspirates of children with lower respiratory tract infections in Seoul, Korea from November 1990 to February 2003 were serotyped by neutralization assay with type-specific antisera. Viral DNAs were extracted from infected cell lysates by the modified Hirt procedure. Genome type(GT) was determined by DNA restriction analysis with 12 restriction enzymess(BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, SalI, SmaI, XbaI, and XhoI). To evaluate the genetic relatedness, pairwise comigrating restriction fragments(PCRF) analysis was performed. Results : Of 382 strains, 33 strains(9%) were Ad1, 45 strains(12%) were Ad2, and 24 strains(6%) were Ad5. Eighteen GTs(Ad1p1-Ad1p7, Ad1a, Ad1b, Ad1b1-Ad1b3, Ad1c, Ad1d, Ad1e, Ad1e1, Ad1e2, Ad1f) among Ad1, 24(Ad2p1-Ad2p11, Ad2a, Ad2a1-Ad2a6, Ad2b, Ad2c, Ad2d, Ad2e, Ad2e1-Ad2e3) among Ad2, and 10(Ad5p1, Ad5p2, Ad5a, Ad5a1-Ad5a7) among Ad5 strains were identified. One or two strains of the vast majority of GTs were isolated during the study period while a few GTs were identified sporadically with more than 2 strains. It is notable that some GTs such as Ad1p5 and Ad5a1 appeared in cluster during a short period. In analysis of genetic relatedness, the degree of PCRFs(pairwise comigrating restriction fragments) for Ad1 varied from 79 to 99%, for Ad2, 82 to 99%, and for Ad5, 85 to 99%. Conclusion : This study established the comprehensive nomenclature systems of Ad1, Ad2, and Ad5. Diverse GTs identified in this study have crucial implications in the genomic diversity and epidemiological characteristics of Ad1, Ad2, and Ad5.

• Molecules and Cells
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• v.26 no.2
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• pp.146-151
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• 2008

The brown planthopper (BPH) is a major insect pest in rice, and damages these plants by sucking phloem-sap and transmitting viral diseases. Many BPH resistance genes have been identified in indica varieties and wild rice accessions, but none has yet been cloned. In the present study we report fine mapping of the region containing the Bph1 locus, which enabled us to perform marker-aided selection (MAS). We used 273 F8 recombinant inbred lines (RILs) derived from a cross between Cheongcheongbyeo, an indica type variety harboring Bph1 from Mudgo, and Hwayeongbyeo, a BPH susceptible japonica variety. By random amplification of polymorphic DNA (RAPD) analysis using 656 random 10-mer primers, three RAPD markers (OPH09, OPA10 and OPA15) linked to Bph1 were identified and converted to SCAR (sequence characterized amplified region) markers. These markers were found to be contained in two BAC clones derived from chromosome 12: OPH09 on OSJNBa0011B18, and both OPA10 and OPA15 on OSJNBa0040E10. By sequence analysis of ten additional BAC clones evenly distributed between OSJNBa0011B18 and OSJNBa0040E10, we developed 15 STS markers. Of these, pBPH4 and pBPH14 flanked Bph1 at distances of 0.2 cM and 0.8 cM, respectively. The STS markers pBPH9, pBPH19, pBPH20, and pBPH21 co-segregated with Bph1. These markers were shown to be very useful for marker-assisted selection (MAS) in breeding populations of 32 F6 RILs from a cross between Andabyeo and IR71190, and 32 F5 RILs from a cross between Andabyeo and Suwon452.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.265-270
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• 2006

Cultivated hot pepper crops showing severe mosaic symptom were found in Korea in 2004 and their causal agent was identified as Cucumber mosaic virus (CMV). These pepper crops was resistant to the virus in the filled, and they belonged to pathotype 0 (P0) resistant pepper. Resistance screening of selected pepper plants showed that a pepper isolate of CMV was the P0 resistance-breaking virus. This P0 resistance-breaking isolate of CMV, named as Ca-P1, was isolated from leaves of the virus-infected Capsicum annuum cv. Manidda that showed systemic severe mosaic symptom. Ca-P1-CMV could induce systemic mosaic symptoms on P0-susceptible (P0-S) and P0-resistant (P0-R) cultivars whereas an ordinary strain (Fny-CMV) could not infect P0-R. This result suggests that Ca-P1-CMV can overcome P0 resistant pepper cultivars. To analyze its genome sequence, the complete nucleotide sequence of RNA3 of Ca-P1-CMV was determined from the infectious full-length cDNA clone of the virus. RNA3 of Ca-P1-CMV consisted of 2,219 nucleotides. Overall sequence homology of RNA3-encoded two viral proteins (movement protein and coat protein) revealed high similarity (75.2-97.2%) with the known CMV strains. By sequence analysis with known representative strains of CMV, Ca-P1-CMV belongs to a typical member of CMV subgroup IB. The resistance and resistance-breaking mechanisms of pepper and counterpart CMV, respectively, remain to be investigated, which will enrich the genetic resources and accelerate CMV-resistant pepper breeding programs.

• IMMUNE NETWORK
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• v.1 no.1
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• pp.77-86
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• 2001

Background: Hepatitis C virus(HCV), a family of Flaviviridae, has a host cell-derived envelope containing a positive-stranded RNA genome, and has been known as the maj or etiological agent for chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. There remains a need to dissect a molecular mechanism of pathogenesis for the development of therapeutic and effective preventive measure for HCV. Identification of cellular receptor is of central importance not only to understand the viral pathogenesis, but also to exploit strategies for prevention of HCV. This study was aimed at identifying peptide mimotopes inhibiting the binding of E2 protein of HCV to MOLT-4 cell. Methods: In this study, phage peptide library displaying a random peptides consisting of 7 or 12 random peptides was employed in order to pan against E2 protein. Free HCV particles were separated from the immune complex forms by immunoprecipitation using anti-human IgG antibody, and used for HCV-capture ELISA. To identify the peptides inhibiting E2-binding to MOLT-4 cells, E2 protein was subj ect to bind to MOLT-4 cells under the competition with phage peptides. Results: Several phage peptides were selected for their specific binding to E2 protein, which showed the conserved sequence of SHFWRAP from 3 different peptide sequences. They were also able to recognize the HCV particles in the sera of HCV patients captured by monoclonal antibody against E2 protein. Two of them, showing peptide sequence of HLGPWMSHWFQR and WAPPLERSSLFY respectively, were revealed to inhibit the binding of E2 protein to MOLT-4 cell efficiently in dose dependent mode. However, few membrane-associated receptor candidates were seen using Fasta3 programe for homology search with these peptides. Conclusion: Phage peptides containing HLGPWMSHWFQR and WAPPLERSSLFY respectively, showed the inhibition of E2-binding to MOLT-4 cells. However, they did not reveal any homologues to cellular receptors from GenBank database. In further study, cellular receptor could be identified through the screening of cDNA library from MOLT-4 or hepatocytes using antibodies against these peptide mimotopes.

• The Plant Pathology Journal
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• v.33 no.5
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• pp.467-477
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• 2017

A nationwide survey was performed to investigate the current incidence of viral diseases in Korean sweet potatoes for germplasm and growing fields from 2011 to 2014. A total of 83.8% of the germplasm in Korea was infected with viruses in 2011. Commercial cultivars that were used to supply growing fields were infected at a rate of 62.1% in 2012. Among surveyed viruses, the incidence of five Potyvirus species that infect sweet potato decreased between 2012 and 2013, and then increased again in 2014. Representatively, the incidence of Sweet potato feathery mottle virus (SPFMV) was 87.0% in 2012, 20.7% in 2013 and then increased to 35.3% in 2014. Unlike RNA viruses, DNA viruses were shown to decrease continuously. The incidence of Sweet potato leaf curl virus (SPLCV) was 5.5% in 2003, 59.5% in 2011, and 47.4% in 2012. It then decreased continuously year by year to 33.2% in 2013, and then 25.6% in 2014. While the infection rate of each virus species showed a tendency to decline, the virus infection status was more variable in 2013 and 2014. Nevertheless, the high rate of single infections and mixed infection combinations were more variable than the survey results from 2012. As shown in the results from 2013, the most prevalent virus infection was a single infection at 27.6%, with the highest rate of infection belonging to sweet potato symptomless virus-1 (SPSMV-1) (12.9%). Compared to 2013, infection combinations were more varied in 2014, with a total of 122 kinds of mixed infection.

• The Korean Journal of Pain
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• v.5 no.2
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• pp.258-262
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• 1992

Herpes zoster is an acute infectious viral disease which affects the posterior spinal root ganglion of the spinal nerve. A single posterior spinal root ganglion or a small number of adjacent ones may be affected, usually on the same side. The corresponding ganglia of the cranial nerve may also be similarly affected. The causative virus, varicella zoster, belongs to the group of host-specific DNA viruses. Postherpetic neuralgia is a continuation of herpes zoster in older patients. Although spontaneous resolution of herpes zoster may be expected in most patients, a significant number experience intractable pain. Postherpetic neuralgia is one of the most difficult problems encountered by physicians. There are many methods for management of postherpetic neuralgia, but there is no method that results in complete remission. Laser has lately come into use to reduce several acute or chronic pains. In order to determine the degree of pain relief by laser, 27 patients of postherpetic neuralgia were irradiated with He Ne, Infrared, and $CO_2$ combine scan moded lasers two to three times per week. The results were as follows: 1) The most frequent site was thoracic vertebral nerve area. 2) Patients younger than 70 years of age showed an improvement rate of 57% vs 27% for those patients older than 70 years of age. 3) Laser therapy proved effective of those patients who received the laser treatment within one month of the onset of the disease. 4) For those patients who received treatment within one month of the disease and reflecting a 50% improvement rate, the average irradiation time was 5.7.