• Toxicological Research
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• v.12 no.1
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• pp.17-20
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• 1996

The effect of Fumonisin B1, a mycotoxin produced by Fusarium moniliforme on bacterial viruses P1 and Lambda, was investigated by the virus plaque assay. Fumonisin B1 inhibited the P1 viral multiplication in the concentration range from $100{\mu}g$/ml to $400{\mu}g$/ml. The inhibition was Fumonisin B1 concentration-dependent. Another bacterial virus Lambda multiplication was also inhibited by lower concentration of Fumonisin B1 ($10{\mu}g$/ml~$50{\mu}g$/ml). This inhibition was dependent on Fumonisin B1 and on virus-Fumonisin B1 reaction time. Sensitivity of bacteriophage Lambda to Fumonisin B1 was higher than that of P1 virus. Lambda vital DNA was treated in vitro with Fumonisin B1 at various concentration. Significant DNA fragmentation by Fumonisin 191 was observed in the agarose gel electrophoresis. Lambda viral DNA was partially digested even in the Fumonisin B1 $10{\mu}g$ and the level of its fragmentation was dependent on Fumonisin B1 amount up to $30{\mu}g$ per assay.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.11
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• pp.861-869
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• 2013

We consider an information system where viruses arrive according to a Poisson process with rate ${\lambda}$. The information system has two types of anti-virus operation policies including 'real-time scan' and 'batch scan.' In the real-time scan policy, a virus is assumed to be scanned immediately after its arrival. Consequently, the real-time scan policy assumes infinite number of anti-viruses. We assume that the time for scanning and curing a virus follows a general distribution. In the batch scan policy, a system manager operates an anti-virus every deterministic time interval and scan and cure all the viruses remaining in the system simultaneously. In this paper we suggest a probability model for the operation of anti-virus software. We derive a condition under which the operating policy is achieved. Some numerical examples with various cost structure are given to illustrate the results.

• Applied Biological Chemistry
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• v.31 no.3
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• pp.219-225
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• 1988

Reverse transcriptase gene of Avian sarcoma virus(ASV) was cloned with a thermoinducible expression vector, pPL-lambda. E. coli N4830 which carries temperature sensitive cI857 la mbda repressor, was transformed with this pPL-pol plasmid DNA. The RNA transcribed by those tranoformants was isolated and analyzed. It was shown that the inserted reverse transcriptase gene of ASV was transcribed at high-level when cells were grown at high temperature.

• Applied Biological Chemistry
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• v.37 no.3
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• pp.148-153
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• 1994

Rice black-streaked dwarf virus (RBSDV), a member of the plant reoviridae fijivirus group, causes a serious damage for rice production in Korea. To characterize the RBSDV genome, virus particles were produced by feeding of planthopper (Laodelphax striatellus F.) carring RBSDV to maize plants for 2 days. In $30{\sim}40$ days after feeding, the viral particles were purified from the infected maize roots by using $10{\sim}40%$ sucrose gradient centrifugation. After treatment of 10% SDS to remove the viral coat proteins, ten viral double-stranded RNAs were resolved in agrose gel electrophoresis. Total dsRNA was then used to synthesize cDNA by reverse transcriptase and a cDNA library was constructed in the ${\lambda}gt11$ vector. The phages that contain RBSDV cDNA fragments were selected by hybridizing with the random-primed probe prepared from RBSDV dsRNAs. After subcloning of several cDNA fragments into the pUC19 plasmid vector, one clone (pRV3) was chosen for sequencing. The pRV3 clone was shown to be located on the RBSDV genome fragment No.3 by RNA gel-blot analysis. Sequence analysis of the clone revealed that the pRV3 contains two partial open reading frames.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.1063-1068
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• 2010

This study compared UV and UV/$H_2O_2$ inactivation of E.coli, a possible indicator microorganism for fecal contamination of water, and $Q{\ss}$ phage, an indicator for pathogenic viruses. UV inactivation of $Q{\ss}$, T4 and lambda phages in actual secondary effluent was investigated, too. As a result, similar inactivation efficiency between $Q{\ss}$ phage and E.coli was observed during UV treatment, while $Q{\ss}$ phage showed higher resistance to UV/$H_2O_2$ than E.coli. $Q{\ss}$ phage resistance to UV or UV/$H_2O_2$ does not reflect those of all pathogenic viruses. However, the result tells that the use of E.coli inactivation efficiency in evaluating microbiological safety of water could not always ensure the sufficient safety from pathogenic viruses. Meanwhile, $Q{\ss}$ phage showed less resistance to UV than T4 and lambda phages, indicating that the use of $Q{\ss}$ phage as an indicator virus may bring insufficient disinfection effectiveness by causing the introduction of lower UV dose than required. Consequently, it can be thought that T4 or lambda phages would be more desirable indicators in ensuring the sufficient disinfection effectiveness for various pathogenic viruses.

• IMMUNE NETWORK
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• v.3 no.4
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• pp.281-286
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• 2003

Background: Hepatitis B virus (HBV) infection is one of the worldwide public health problem affecting about 300 million people. The envelope protein of HBV consists of three components known as preS1, preS2, and S antigen. According to the recent study, anti-HBs Ab showed effective neutralization ability against HBV from chronic hepatitis B and liver transplant patients, suggesting the possible development of therapeutic antibody. Methods: Spleen cells immunized with S antigen of HBV were fused with myeloma cell line to obtain HBsAg specific monoclonal antibodies. High affinity antibodies against HBsAg (adr, ad and ay type) were selected by competitive ELISA method. Nucleotide sequence of the variable regions of monoclonal antibodies was analyzed by RT-PCR followed by conventional sequencing method. Results: We produced 14 murine monoclonal antibodies which recognize S antigen of HBV. Two of them, A9-11 and C6-9 showed the highest affinity. The sequence analysis of A9-11 revealed that variable regions of the heavy chain and light chains are members of mouse heavy chain I (B) and light chain lambda 1, respectively. Likewise, the sequence analysis of C6-9 revealed that variable regions of the heavy chain and light chains are members of mouse heavy chain II (B) and light chain kappa 1, respectively. Neutralization assay showed that A9-11 and C6-9 effectively neutralize the HBV infection. Conclusion: These results suggest that A9-11 and C6-9 mouse monoclonal antibodies can be used for the development of therapeutic antibody for HBV infection.

• Childhood Kidney Diseases
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• v.12 no.1
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• pp.88-92
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• 2008

Infection of Epstein-Barr virus(EBV) gives rise to a broad spectrum of clinical manifestations in children. Although renal involvement is rare, diverse renal manifestations are known from hematuria to acute renal failure. Secondary membranous nephropathy(MN) associated with systemic EBV infection is an uncommon renal pathology and only two cases have been reported. We are adding another case of MN associated with EBV infection in a child. An 8-year-old girl was admitted for renal biopsy. She had been followed up for microscopic hematuria and intermittent proteinuria for 5 months. There had been no specific findings in serology and radiology. Tonsil biopsy had been done due to exudative tonsillar hypertrophy and enlarged multiple cervical lymph nodes. And it showed EBV-associated lymphoproliferative findings. Serologic tests for EBV showed positive evidence of recent infection; viral capsid antigen(VCA) IgM was borderline positive, VCA IgG and early antigen IgG were positive, and EB nuclear antigen IgG was negative. In Situ Hybridization of tonsil for EBV mRNA was positive. Because her proteinuria and hematuria were aggravated at that time(protein 3 +, RBC >60/HPF), renal biopsy was done. Renal biopsy showed the findings of MN, characterized by thickened capillary walls with epimembranous spikes on light microscopy and subepithelial, mesangial and subendothelial electron dense deposits on electron microscopy. On immunofluorescence microscopy, IgG, C1q, kappa and lambda chains were positive. After steroid administration, proteinuria and hematuria resolved gradually within 6 months.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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• pp.515-525
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• 2020

Interferon (IFN)-λ plays an essential role in mucosal cells which exhibit strong antiviral activity. Lactobacillus plantarum (L. plantarum) has substantial application potential in the food and medical industries because of its probiotic properties. Alphacoronaviruses, especially porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), cause high morbidity and mortality in piglets resulting in economic loss. Co-infection by these two viruses is becoming increasingly frequent. Therefore, it is particularly important to develop a new drug to prevent diarrhea infected with mixed viruses in piglets. In this study, we first constructed an anchored expression vector with CWA (C-terminal cell wall anchor) on L. plantarum. Second, we constructed two recombinant L. plantarum strains that anchored IFN-λ3 via pgsA (N-terminal transmembrane anchor) and CWA. Third, we demonstrated that both recombinant strains possess strong antiviral effects against coronavirus infection in the intestinal porcine epithelial cell line J2 (IPEC-J2). However, recombinant L. plantarum with the CWA anchor exhibited a more powerful antiviral effect than recombinant L. plantarum with pgsA. Consistent with this finding, Lb.plantarum-pSIP-409-IFN-λ3-CWA enhanced the expression levels of IFN-stimulated genes (ISGs) (ISG15, OASL, and Mx1) in IPEC-J2 cells more than did recombinant Lb.plantarum-pSIP-409-pgsA'-IFN-λ3. Our study verifies that recombinant L. plantarum inhibits PEDV and TGEV infection in IPEC-J2 cells, which may offer great potential for use as a novel oral antiviral agent in therapeutic applications for combating porcine epidemic diarrhea and transmissible gastroenteritis. This study is the first to show that recombinant L. plantarum suppresses PEDV and TGEV infection of IPEC-J2 cells.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.39.18-39.18
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• 2021

Background: Interferon lambda receptor 1 (IFNLR1) is a type II cytokine receptor that clings to interleukins IL-28A, IL29B, and IL-29 referred to as type III IFNs (IFN-λs). IFN-λs act through the JAK-STAT signaling pathway to exert antiviral effects related to preventing and curing an infection. Although the immune function of IFN-λs in virus invasion has been described, the molecular mechanism of IFNLR1 in that process is unclear. Objectives: The purpose of this study was to elucidate the role of IFNLR1 in the pathogenesis and treatment of porcine reproductive and respiratory syndrome virus (PRRSV). Methods: The effects of IFNLR1 on the proliferation of porcine alveolar macrophages (PAMs) during PRRSV infection were investigated using interference and overexpression methods. Results: In this study, the expressions of the IFNLR1 gene in the liver, large intestine, small intestine, kidney, and lung tissues of Dapulian pigs were significantly higher than those in Landrace pigs. It was determined that porcine IFNLR1 overexpression suppresses PRRSV replication. The qRT-PCR results revealed that overexpression of IFNLR1 upregulated antiviral and IFN-stimulated genes. IFNLR1 overexpression inhibits the proliferation of PAMs and upregulation of p-STAT1. By contrast, knockdown of IFNLR1 expression promotes PAMs proliferation. The G0/G1 phase proportion in IFNLR1-overexpressing cells increased, and the opposite change was observed in IFNLR1-underexpressing cells. After inhibition of the JAK/STAT signaling pathway, the G2/M phase proportion in the IFNLR1-overexpressing cells showed a significant increasing trend. In conclusion, overexpression of IFNLR1 induces activation of the JAK/STAT pathway, thereby inhibiting the proliferation of PAMs infected with PRRSV. Conclusion: Expression of the IFNLR1 gene has an important regulatory role in PRRSV-infected PAMs, indicating it has potential as a molecular target in developing a new strategy for the treatment of PRRSV.

• Clinical and Experimental Pediatrics
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• v.62 no.11
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• pp.416-421
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• 2019

Background: The seropositivity rate of hepatitis B surface antigen (anti-HBs) antibodies is known to be ≥95% after hepatitis B virus vaccination during infancy. However, a low level or absence of anti-HBs in healthy children is discovered in many cases. Recent studies in adults reported that a reduced anti-HBs production rate is related to obesity. Purpose: To investigate whether body mass index (BMI) affects anti-HBs levels in healthy children following 3 serial dose vaccinations in infancy. Methods: We recruited 1,200 healthy volunteers aged 3, 5, 7, or 10 years from 4-day care centers and 4 elementary schools. All subjects completed a questionnaire including body weight, height, and vaccine type received. Levels of serum hepatitis B surface antigen (HBsAg) and anti-HBs in all subjects were analyzed using electrochemiluminescence immunoassay. The standardized scores (z score) for each sex and age were obtained using the lambda-mu-sigma method in the 2017 Korean National Growth Charts for children and adolescents. Results: Our subjects (n=1,200) comprised 750 males (62.5%) and 450 females (37.5%). The overall anti-HBs seropositivity rate was 57.9% (695 of 1,200). We identified significant differences in mean BMI values between seronegative and seropositive groups (17.45 vs. 16.62, respectively; P<0.001). The anti-HBs titer was significantly decreased as the BMI z score increased adjusting for age and sex (B=-15.725; standard error=5.494; P=0.004). The probability of anti-HBs seropositivity based on BMI z score was decreased to an OR of 0.820 after the control for confounding variables (95% confidence interval, 0.728-0.923; P=0.001). Conclusion: There was a significant association between anti-HBs titer and BMI z score after adjustment for age and sex. Our results indicate that BMI is a potential factor affecting anti-HBs titer in healthy children.