• Clinical and Experimental Pediatrics
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• v.50 no.8
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• pp.803-810
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• 2007

• The Journal of Korean Society of Virology
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• v.28 no.3
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• pp.247-265
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• 1998

To determine the sequence and expression of the VP7 gene of Korean isolates (CAU-9), viral RNA was purified and used for cDNA amplification by RT-PCR. The VP7 cDNA was cloned, sequenced, and expressed using baculovirus expression system. The result showed that the sequence homologies CAU-9 compared with foreign isolated strains Wa, 417, TMC-II, 95B and SA11 were ranged from 74.0% to 95.1 % of nucleotide sequence and 35% to 43% of amino acid sequence, respectively. High homology of CAU-9 was observed in Japanease isolates 417 (nucleotide sequence homology was 95.1% and amino acid sequence homology was 43%). To express VP7 gene, the VP7 cDNA was cloned into pCR-Bac vector and inserted into the genome of baculovirus adjacent to the polyhedrin promoter by cotransfection of Spodoptera frugiperda (Sf9) insect cells with wild type baculovirus DNA. In antigenic analysis of Sf9 cells inoculated with the recombinant VP7, immunofluorescence assay revealed positive for viral antigens. In metabolic labeling of Sf9 cell lysates infected with recombinant baculoviruses, it was revealed that the protein of 34 kDa was expressed. The limited study of expressed VP7 protein inoculated with guinea pigs failed to elicit neutalizing antibody. As a results, the sequence analysis and expression of VP7 protein of rotavirus CAU-9 isolated from an infant in Korea could permit the conformation and development of virus like particles which may be useful in designing vaccine strategy.

• Journal of Life Science
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• v.32 no.12
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• pp.919-928
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• 2022

As seen in the COVID-19 pandemic, unexpected emergence of new viruses presents serious concern on public health. Especially, the absence of effective vaccines or antiviral drugs against emerging viruses significantly increases the severity of disease and duration of viral circulation among population. Natural products have served as a major source for safe and effective antiviral drugs. In this study, we examined the virucidal activity of medical herb extracts with a view to discover novel antiviral agents with desired levels of safety and antiviral efficacy. Ethanol extracts of ten selected medical herbs were tested for antioxidant activity and in-vitro cytotoxicity in various animal cell lines. Of note, the herbal extracts showed broad and potent virucidal activities against rotavirus, hepatitis A virus, and influenza A virus. The extracts of Sorbus commixta and Glycyrrhiza uralensis showed strong virucidal activities against influenza A virus. We also examined whether the extracts of Sorbus commixta and Glycyrrhiza uralensis can be used as inactivating agents to prepare an inactivated viral vaccine. In a mouse model, influenza A virus inactivated by the extracts elicited high levels of neutralizing antibodies, and the vaccination provided complete protection against lethal challenge. These results suggest that herb-derived natural products can be developed to antiviral drugs as well as inactivating agents for preparation of inactivated viral vaccines.

• Pediatric Infection and Vaccine
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• v.21 no.2
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• pp.96-103
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• 2014

Purpose: The aim of this study is that the prevalence of rotavirus infection was evaluated by each group and clinical features of group A, B and C rotaviruses infections were described respectively to compare one with another. Methods: Between January 2010 and December 2010, we enrolled a group of children below 10 years of age admitted for management of acute diarrhea at the Catholic University of Korea Bucheon St. Mary's Hospital. A total of 310 stool samples documented to be free of common bacterial pathogens were collected from children with diarrhea. The presence of group A, B or C rotavirus is indicated by amplification of DNA segments of the expected lengths after the first and second PCRs Results: In a total of 310 stool specimens, 40 (12.9%) specimens were positive for rotaviruses. These included 23 (7.4%) positive for group A, 5 (1.6%) for group B and 12 (3.9%) for group C rotaviruses. Group B rotavirus infected patients had significantly less diarrheas per day (group A: P =0.01, group C: P =0.01) and shorter duration of vomiting days (group A: P =0.03, group C: P =0.03) than those with group A and C rotaviruses infection respectively. All the group B rotaviruses had been isolated in March and October. Group C rotavirus infections were prevalent during late summer and early winter and peaked in October. Conclusion: These findings indicate that group B and C rotaviruses are notable causes or the contributing causes of diarrhea among infants and children in Korea.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.336-344
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• 1998

Eight monoclonal antibodies(MAbs) against the transmissible gastroenteritis virus (TGEV) were produced and characterized. Four of the MAbs were produced against a reference TGEV, Purdue strain(P115) and the others were produced against the Korean vaccine virus, Pyungtaek strain. Only one MAb(5C8) produced against P115 had neutralizing activity and was found to be E2 protein-specific. The other seven MAbs(4E2, 4G8, 5H6, 1F8, 2C6, 5H5, and 3A6) had specificity of nucleocapsid protein and no neutralizing activity. All MAbs reacted with different strains of TGEV, but none of the MAbs was reactive with porcine enteropathogenic viruses such as rotavirus, epidemic diarrhea virus and enterovirus by fluorescence antibody(FA) test.

• Korean Journal of Veterinary Service
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• v.40 no.3
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• pp.187-192
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• 2017

In this report, fifteen monoclonal antibodies (MAbs) against an avian influenza virus (H9N2 subtype) were newly produced and characterized. These MAbs proved to react to the epitopes of nucleocapsid protein (NP), hemagglutinin (HA), neuraminidase (NA) and non-structural protein 1 (NS1) of Korean H9N2 strain, respectively. Two HA-specific MAbs showed the ability to inhibit the hemagglutination activity of H9N2 subtype avian influenza virus when tested by hemagglutination inhibition (HI) assay. All MAbs did not cross-react with other avian-origin viruses (Newcastle disease virus, infectious bursal disease virus, infectious bronchitis virus and avian rotavirus) by immunofluorescence test or enzyme-linked immunosorbent assay. The MAbs produced in this study could be useful as the materials for diagnostics and therapeutics against Korean-lineage H9N2 virus infections.

• Pediatric Infection and Vaccine
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• v.14 no.2
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• pp.155-161
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• 2007

Purpose : We evaluated the epidemiologic characteristics of rotavirus gastroenteritis in Daejeon, Korea from January 2001 through December 2005. Methods : We retrospectively analyzed 540 medical records of children with gastroenteritis, who had been hospitalized at The Catholic University of Korea, Daejeon St. Mary's Hospital and were tested positive by rotavirus stool examinations (latex agglutination or immunechromatography). Results : The mean age was $21.8{\pm}15.3$ months (ranged from 2 months to 9 years of age) and the distribution of children were 144 cases (26.7%) in <1 year of age, 228 (42.2%) in 1 year of age, and 93 (17.2%) in 2 years of age, and the 505 children (93.5%) were less than 4 years of age. The male-to-female ratio was 1.4:1. The mean annual number of cases was 108, with a relative even occurrence in each year. Although the patients with rotaviral gastroenteritis occurred through the year, a higher rate of occurrence was seen in spring (March to May, 40.8%) and winter season (December to February, 37.9%), without significant differences in each year. Conclusion : In Daejeon, Korea, rotaviral gastroenteritis have occurred in children less than 4 years of age, with slight annual variations and similar seasonal occurrence in the recent years. The data indicate that the recent trend in peak rotavirus activity is different from that observed decades ago in Korea.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.147-155
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• 2006

Purpose : The purpose of this study is to evaluate epidemiological data of pathogens obtained from stool exams and compare them with the clinical course in pediatric patients with symptoms of acute gastroenteritis. Methods : Subjects were selected from patients presenting with symptoms of acute gastroenteritis who visited the outpatient clinic or who were admitted to the Dankook University Hospital from December of 2004 to December of 2005. Stool exams for 17 pathogens was performed. RT-PCR was used to detect norovirus and enzyme-linked immunoabsorbant assay (ELISA) was used to detect rotavirus, adenovirus and astrovirus in the subjects stool samples. Ten different species of bacteria(Salmonella spp., Shigella spp., Clostridium perfrigens, Campylobacter spp., Escherichia coli, Vibrio spp., Staphylococcus aureus, Bacillus cereus, Yersinia spp., and L. monocytogenes) were each selectively cultivated and enzyme immunoassays(EIA) was used to test for antigens for C. parvum, E. histolytica and G. lamblia. Retrospective chart review was performed for comparisons of clinical manifestations. Results : A total of 215 subjects was selected and of these 89 cases(41.4%) showed positive results for at least one pathogen. Male to female ratio was 1.3:1. Age distribution showed 4 cases less than one month(4.5%), 4 cases from 1~2 months(4.5%), 24 cases from 3~12 months(26.7%), 47 cases form 13~48 months(52.8%), 10 cases greater than 48 months (21.2%). Viruses showed the greatest proportion of cases with 68 subjects(77.5%), of these rotavirus being the most commonly reported in 50 cases. Bacteria was identified in 26 cases (29.2%), of these nontyphoidal salmonella was noted in 10 cases. Protozoa followed with 21 cases(23.6%), of these C. parvum was noted in 11 cases and G. lamblia was noted in 10 cases. Mixed infections with more than two pathogens were seen in 22 cases(24.7%), of these viral infection with accompanying parasitic infection was seen in 12(54.5%) cases. Conclusion : In this study we examined various pathogens known to cause acute gastroenteritis in children. Further studies for various pathogens can provide useful information for management of the acute gastroenteritis.

• Pediatric Infection and Vaccine
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• v.16 no.2
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• pp.123-130
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• 2009

Purpose : This study was performed to determine the clinical and epidemiologic characteristics of nosocomial rotavirus gastroenteritis. Methods : We retrospectively analyzed 628 medical records of patients with rotavirus gastroenteritis between 2001 and 2005. The patients were divided into two groups (the community-acquired group [528 cases] and the nosocomial group [100 cases]. The epidemiologic and clinical indices between the groups were analysed. For clinical comparison, 100 agematched cases were selected from the community-acquired group. Results : The male-to-female ratio was similar (1.4:1 vs. 1.5:1), but the mean age was lower in the nosocomial group compared to the community-acquired group (21.9${\pm}$15.5 months vs. 16.6${\pm}$10.3 months, P <0.001). The patterns of age distribution, annual frequency, and seasonal distribution were similar in both groups. The proportions of nosocomial cases in each year ranged from 9.8% to 22.4% of annual rotaviral infections, and these were not proportional to annual cases. The duration of fever appeared more prominent in the nosocomial group, and the severity of diarrhea was not different between the groups. The cases with a BUN >20 mg/dL were more in the community-acquired group (16% vs. 4%, P=0.01). Conclusion : The clinical and epidemiologic charateristics of nosocomial rotavirus gastroenteritis were similar and correlated to those of the community-acquired gastroenteritis.

• Pediatric Infection and Vaccine
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• v.19 no.1
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• pp.19-27
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• 2012

Purpose : As the number of children who attend child care centers has increased, concerns has increased about the effect of child day care on childhood illness. This study was conducted to examine the relationship between experience in child care and common infectious diseases in children under 5 years of age. Methods : Data were collected by surveying 1,000 respondents with children under age 5 through online interviews using a structured questionnaire. The contents of the survey were composed of demographic characteristics, child care facilities usage, experience in infectious diseases, and immunization status Results : Among the 1,000 children <5 years of age, 78.5% attended a child care facility. Rates of common communicable illnesses were higher in children in child care than for children reared exclusively at home. The predominant communicable diseases which the respondents' children experienced, in order of decreasing frequency, were gastroenteritis (47.1%), otitis media (41.8%) and pneumonia (19.1%). The immunization rate of vaccines that are not included the national immunization program (NIP) (Haemophilus influenzae type b vaccine - 76.6%, hepatitis A vaccine - 63.3%, pneumococcal vaccine - 59.4%, rotavirus vaccine - 43.1%) was lower than that of the NIP vaccines (90.4%) Conclusion : Children in child care experience more bouts of common infectious disease, so nationwide policies to prevent or to control the spread of infectious agents in a child-care should be available and appropriate immunization should be emphasized as the most effective method for the control of infectious disease for children.