• Journal of Veterinary Science
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• v.21 no.6
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• pp.85.1-85.6
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• 2020

A cold-adapted porcine reproductive and respiratory syndrome virus (CA-VR2332) was generated from the modified live virus strain VR2332. CA-VR2332 showed impaired growth when cultured at 37℃ with numerous mutations (^S731^F, ^E819^D, ^G975^E, and ^D1014^N) in the hypervariable region of the NSP2, in which the mutation ^S731^F might play a vital role in viral replication at 30℃. Conserved amino acid sequences of the GP5 protein suggests that CA-VR2332 is a promising candidate for producing an effective vaccine against PRRSV infection. Further studies on replication and immunogenicity in vivo are required to evaluate the properties of CA-VR2332.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.255-263
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• 2010

Inclusion body hepatitis-hydropericardium syndrome (IBH-HPS) is an acute viral disease usually found in broilers aged from 3 to 5 weeks and causes up to 75% mortality. Among the 12 serotypes of fowl adenovirus group 1, serotype-4 (FAdV-4) was identified as a primary agent of IBH-HPS and was usually isolated in IBH-HPS cases in Korea since 2007. To prevent these IBH-HPS outbreaks in Korea, we developed the FAdV-4 inactivated vaccine using Korean isolate (ADL070244) and evaluated the efficacy of this vaccine. For the efficacy test, 2-week-old specific-pathogen-free (SPF) chickens intramuscularly inoculated with 1 or 2 dose of inactivated vaccine were used and challenged with FAdV-4 through either intramuscular or oral route at 2 weeks after vaccination. The vaccine induced good seroconversion which was confirmed by agar gel precipitation (AGP) test. In addition, the vaccine could decrease the FAdV-4 detection rate and histological lesion severity such as lymphocyte infiltration and necrosis in the liver comparing with those of non-vaccination group. Based on the current results, the developed FAdV-4 inactivated vaccine in this study was effective in the terms of reduction of virus detection rate and histological lesions severity. However, it was difficult to confirm the efficacy of the vaccine clearly because of no mortality and clinical signs in the non-vaccinated group after challenge. Therefore, we need further study to develop a standard challenged model system which could clearly evaluate the efficacy of the vaccines for FAdV-4.

• Korean Journal of Head & Neck Oncology
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• v.19 no.1
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• pp.25-33
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• 2003

Background and Objectives: The Herpes Simplex type 2 Defective Infectious Single Cycle virus (DISC virus) is attenuated virus originally produced as viral vaccines but are also efficient gene transfer vehicle. The main goals of this study were to examine the efficiencies of the gene transfer using DISC vectors for various head and neck squamous cell carcinoma cell lines and to evaluate the efficacy of vaccination with DISC virus carrying a immunomodulatory genes (GM-CSF) as cancer therapy in a organotopic oral cavity squamous cell cancer model. Materials and Methods : We determinated the gene transfer efficiency of DISC virus by x-gal stain method and proved gene and protein expression of DISC-GMCSF transfected SCCVII cells by RT-PCR and ELISA method. Also we evaluated the ex vivo vaccination effects of SCCVII/GMCSF (DISC-GMCSF transfected SCCVII vaccine) vaccine on preventing the recurrence of micro-residual tumor. After the vaccination of SCCVII/GMCSF, specific cytotoxic T-cell responses was evaluated by CTL assay. Results: At an MOI of 10 DISC virus showed 64-88% of transfection rates in various head and neck squamous cancer cell lines. SCCVII cells transduced by DISC virus vector (MOI=10) carrying the GM-CSF gene, produced 4.5 nanogram quantities of GM-CSF per $10^6$ cells. In vivo vaccination using tumor cells transduced ex vivo with DISC-GMCSF resulted in better protection rate against subsequent tumor recurrence in organotopic oral cavity cancer model. Although tumor free survival rate was not statistically significantly increased in vaccination group (p=0.078), tumor specific cytotocic T-cell responses were significantly increased in SCCVII/GMCSF vaccination group. Conclusion: These data demonstrate that; 1) The DISC virus vector is capable of efficient gene transfer to various head and neck squamous cancer cell lines, 2) GM-CSF secreting genetically modified tumor vaccine (SCCVII/GMCSF) efficiently protected against tumor recurrence in organotopic micro-residual oral cavity cancer model and produced tumor specific cytotoxic T-cell response. DISC virus-mediated, cytokine gene transfer may prove to be useful as a clinical therapy for head and neck cancers.

• Pediatric Infection and Vaccine
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• v.19 no.1
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• pp.28-36
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• 2012

Purpose : This study was conducted to evaluate epidemiological data of the viral pathogens obtained from stool exams and provide information on the regional prevalence of infectious diarrheal disease west in Gyeonggi Province, Korea. Methods : We enrolled a cohort of children <10 years of age admitted for treatment of acute diarrhea at Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea. In total, 310 fecal specimens, documented to be free of common bacterial pathogens, were collected from pediatric patients during a 12-month period from January to December 2009 and were tested for the presence of rotavirus, parechovirus, adenovirus, astrovirus, enterovirus, and norovirus using polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) assay. Results : The most common virus was parechovirus (16%), followed by adenovirus (15%), astrovirus (14%), rotavirus (13%), and enterovirus (5%). Interestingly, only one of the specimens was positive for norovirus. Single infection cases were detected in 173 (55.8%) of the 310 children, whereas mixed viral infections were detected in 10 (3.2%) of the same children. Viral gastroenteritis generally showed a double peak of incidence. Parechovirus, rotavirus, and adenovirus shared a similar pattern of peak incidence with overall viruses; however, astrovirus infections occurred more frequently in the spring. Eighty-five percent of the confirmed viral gastroenteritis cases developed in under 24 months. Conclusion : The results support the importance of parechovirus, adenovirus, astrovirus, and enterovirus as causative agents of diarrhea in children, which may be underestimated by current routine diagnostic testing.

• Pediatric Infection and Vaccine
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• v.17 no.2
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• pp.130-136
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• 2010

Purpose : The purpose of this study is to identify the viral etiology of acute respiratory illnesses and to determine epidemiology in outpatients in Busan, Korea. Methods : We collected nasal wash samples from 990 patients who visited the hospital for acute respiratory illnesses between January 2007 and December 2008. Extracted DNA or RNA from specimens was used for viral detection by an RT-PCR method. Results : Of a total of 990 samples, viruses were detected in 351 cases (35.5%). The ratio of male to female was 1.6:1 and 93.7% were less than 5 years old. Rhinovirus was detected year-round in 202 cases (57.5%), respiratory syncytial virus from October to March in 57 cases (16.2%), adenovirus year-round in 37 cases (10.5%), influenza virus from December to April in 21 cases (6%), bocavirus from January to August in 15 cases (4.3%), parainfluenza virus from April to July in 9 cases (2.6%), coronavirus from January to July in 7 cases (2%), and enterovirus from June to September in 3 cases (0.9%). Conclusion : We identified the etiology and epidemiology of viruses that caused the acute respiratory diseases that were prevalent in Busan, 2007-2008. Further surveillance will be necessary.

• Pediatric Infection and Vaccine
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• v.24 no.1
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• pp.44-53
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• 2017

Purpose: The aim of this study was to investigate the risk factors for posttransplant lymphoproliferative disorder (PTLD) and to evaluate the association between Epstein-Barr viral load and the development of PTLD in pediatric heart transplant recipients. Methods: We reviewed children aged <18 years who underwent heart transplantation and quantitative analysis of blood Epstein-Barr virus (EBV) viremia at our institute from January 2006 to March 2015. Clinical characteristics and EBV viral loads were compared according to the presence of PTLD. Results: Over 9 consecutive years, a total of 40 heart transplant recipients, were included. Among 28 children with available EBV viral load measurements, seven patients (25%) had EBV viremia only defined as at least one time of ${\geq}457copies/mL$. PTLD occurred in three recipients (7.5%) 4.3, 6.3, and 17.0 months after transplant and all PTLD cases had preceding EBV viremia. The median age at transplant was 5.3 years (range, 0.5 to 6.0 years) in the PTLD group, compared with 11.9 years (range, 0.3 to 17.8 years) in the non-PTLD group (P=0.021). The median values of the peak EBV levels in the PTLD group were 3,452,170 copies/mL (range, 46,750 to 7,622,910 copies/mL); the peak EBV levels in the non-PTLD group were 3,112 copies/mL (range, 2,250 to 103,000 copies/mL). Conclusions: Younger age at transplant and presence of EBV viremia were associated with the development of PTLD in pediatric heart transplant recipients. A prospective study will be required to determine the blood EBV load for predicting the development of PTLD in these patients.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.143-148
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• 2005

Purpose : Hypogammaglobulinemia has been observed in nephrotic syndrome, but its pathophysiology remains unknown. We evaluated serum immunoglobulins, IgG subclasses, and vaccine-induced viral antibodies(anti-hepatitis B surface IgG and anti-measles IgG) in children with minimal change nephrotic syndrome(MCNS). Methods : Using the stored sera, the levels of immunoglobulin(IgC, IgM, IgA, and IgC) and IgG subclasses(IgG 1, 2, ,3, and 4), anti-HBs Ab and anti-measles IgG of 21 children with MCNS were analyzed and compared to those of 25 age-matched healthy children. Results : The mean values of IgG and IgG1 were $390{\pm}187\;mg/dL$ and $287{\pm}120\;mg/dL$ in nephrotic children, and $1,025{\pm}284\;mg/dL$ and $785{\pm}19\;mg/dL$ in control children, respectively. The values of the total IgG and the 4 IgG subclasses in nephrotic children were all significantly depressed(P<0.001), but the IgM($251{\pm}183\;mg/dL\;vs. 153{\pm}55\;mg/dL$, P=0.02) and IgE values(P=0.01) were elevated, and the IgA values were not changed. The seropositivity of anti-HBs IgG was 42.9$\%$(9 of 21 cases) in the MCNS group and 52$\%$(13/25) in the control group, and that of anti-measles IgG was 75$\%$(16/21) and 92$\%$(23/25), respectively, but there was no statistical difference between the two groups. Conclusion : IgG and IgG subclass levels in MCNS children are all depressed without significant seronegativity of the vaccine-induced viral antibodies. Further studies are needed to resolve the cause of hypogammaglobulinemia in MCNS. (J Korean Soc Pediatr Nephrol 2005;9:143-148)

• Pediatric Infection and Vaccine
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• v.27 no.2
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• pp.90-101
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• 2020

Purpose: The multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) test developed recently can help detect enteric pathogens of acute gastroenteritis (AGE). This study aimed to investigate the epidemiology of pathogens in children with AGE using the multiplex RT-PCR. Methods: From May 2015 to June 2018, multiplex RT-PCR tests were performed to identify pathogens in the feces of pediatric patients diagnosed with AGE at a secondary hospital in Seoul, Korea. Results: Of the 1,366 stool samples examined for viral pathogens, 483 (35.3%) tested positive for ≥1 pathogen. Group A rotavirus (RV) was detected in 106 cases (7.8%). The positivity rate increased annually from 3.0% (8/263) to 16.7% (48/288) and surged in 2018 (P<0.001). Norovirus (NoV) GII was the most common viral pathogen (263/1,366, 19.3%), and the positivity rate did not increase during the 3 years. Of the 304 stool samples tested for bacterial pathogens, Campylobacter spp. was the most common bacterial pathogen (32/304, 10.5%), followed by Clostridium difficile (22/304, 7.2%) and Salmonella spp. (17/304, 5.6%). The positivity rate of these bacterial pathogens did not change significantly during the study period. Conclusions: NoV GII is the main pathogen in childhood AGE since the introduction of RV vaccine, yet the number of rotavirus-infected patients increased during our study, especially in 2018. Therefore, further research is needed including the possibility of emergence of novel RV strains. Campylobacter spp. is the predominant cause of bacterial AGE in children. For proper treatment, the clinical characteristics of the bacteria should be taken into consideration, and continuous monitoring is necessary.

• Genomics & Informatics
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• v.20 no.2
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• pp.21.1-21.14
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• 2022

The influenza A viruses have high mutation rates and cause a serious health problem worldwide. Therefore, this study focused on genome characterization of the viruses isolated from Thai patients based on the next-generation sequencing technology. The nasal swabs were collected from patients with influenza-like illness in Thailand during 2017-2018. Then, the influenza A viruses were detected by reverse transcription-quantitative polymerase chain reaction and isolated by MDCK cells. The viral genomes were amplified and sequenced by Illumina MiSeq platform. Whole genome sequences were used for characterization, phylogenetic construction, mutation analysis and nucleotide diversity of the viruses. The result revealed that 90 samples were positive for the viruses including 44 of A/H1N1 and 46 of A/H3N2. Among these, 43 samples were successfully isolated and then the viral genomes of 25 samples were completely amplified. Finally, 17 whole genomes of the viruses (A/H1N1, n=12 and A/H3N2, n=5) were successfully sequenced with an average of 232,578 mapped reads and 1,720 genome coverage per sample. Phylogenetic analysis demonstrated that the A/H1N1 viruses were distinguishable from the recommended vaccine strains. However, the A/H3N2 viruses from this study were closely related to the recommended vaccine strains. The nonsynonymous mutations were found in all genes of both viruses, especially in hemagglutinin (HA) and neuraminidase (NA) genes. The nucleotide diversity analysis revealed negative selection in the PB1, PA, HA, and NA genes of the A/H1N1 viruses. High-throughput data in this study allow for genetic characterization of circulating influenza viruses which would be crucial for preparation against pandemic and epidemic outbreaks in the future.

• Journal of Ginseng Research
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• v.47 no.1
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• pp.123-132
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• 2023

Background: Pseudotyped virus systems that incorporate viral proteins have been widely employed for the rapid determination of the effectiveness and neutralizing activity of drug and vaccine candidates in biosafety level 2 facilities. We report an efficient method for producing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus with dual luciferase and fluorescent protein reporters. Moreover, using the established method, we also aimed to investigate whether Korean Red Ginseng (KRG), a valuable Korean herbal medicine, can attenuate infectivity of the pseudotyped virus. Methods: A pseudovirus of SARS-CoV-2 (SARS-2pv) was constructed and efficiently produced using lentivirus vector systems available in the public domain by the introduction of critical mutations in the cytoplasmic tail of the spike protein. KRG extract was dose-dependently treated to Calu-3 cells during SARS2-pv treatment to evaluate the protective activity against SARS-CoV-2. Results: The use of Calu-3 cells or the expression of angiotensin-converting enzyme 2 (ACE2) in HEK293T cells enabled SARS-2pv infection of host cells. Coexpression of transmembrane protease serine subtype 2 (TMPRSS2), which is the activator of spike protein, with ACE2 dramatically elevated luciferase activity, confirming the importance of the TMPRSS2-mediated pathway during SARS-CoV-2 entry. Our pseudovirus assay also revealed that KRG elicited resistance to SARS-CoV-2 infection in lung cells, suggesting its beneficial health effect. Conclusion: The method demonstrated the production of SARS-2pv for the analysis of vaccine or drug candidates. When KRG was assessed by the method, it protected host cells from coronavirus infection. Further studies will be followed for demonstrating this potential benefit.