• Journal of Sensor Science and Technology
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• v.23 no.4
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• pp.278-283
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• 2014

In this study, we propose an immunosensor using zinc oxide nanorods (NRs) inside PDMS channel for detecting the influenza A virus subtype H7N9. ZnO with high isoelectric point (IEP, ~9.5) makes it suitable for immobilizing proteins with low IEP. In this proposed H7N9 immunosensor structure ZnO NRs were grown on the PDMS channel inner surface to immobilize H7N9 capture antibody. A sandwich enzyme-linked immunosorbent assay (ELISA) method with was used 3,3',5,5' tetramethylbenzidine (TMB) for detecting H7N9 influenza virus. The immunosensor was evaluated by amperometry at various H7N9 influenza antigen concentrations (1 pg/ml - 1 ng/ml). The redox peak voltage and current were measured by amperometry with ZnO NWs and without ZnO NWs inside PDMS channel. The measurement results of the H7N9 immunosensor showed that oxidation peak current of TMB at 0.25 V logarithmically increased from 2.3 to 3.8 uA as the H7N9 influenza antigen concentration changed from 1 pg/ml to 1 ng/ml. And then we demonstrated that ZnO NRs inside PDMS channel can improve the sensitivity of immunosensor to compare non-ZnO NRs inside PDMS channel.

• Journal of Veterinary Science
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• v.24 no.1
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• pp.5.1-5.16
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• 2023

The H9N2 avian influenza (AI) has become endemic in poultry in many countries since the 1990s, which has caused considerable economic losses in the poultry industry. Considering the long history of the low pathogenicity H9N2 AI in many countries, once H9N2 AI is introduced, it is more difficult to eradicate than high pathogenicity AI. Various preventive measures and strategies, including vaccination and active national surveillance, have been used to control the Y439 lineage of H9N2 AI in South Korea, but it took a long time for the H9N2 virus to disappear from the fields. By contrast, the novel Y280 lineage of H9N2 AI was introduced in June 2020 and has spread nationwide. This study reviews the history, genetic and pathogenic characteristics, and control strategies for Korean H9N2 AI. This review may provide some clues for establishing control strategies for endemic AIV and a newly introduced Y280 lineage of H9N2 AI in South Korea.

• Journal of Microbiology and Biotechnology
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• v.33 no.12
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• pp.1576-1586
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• 2023

Vaccination is the most effective method for preventing the spread of the influenza virus. Cell-based influenza vaccines have been developed to overcome the disadvantages of egg-based vaccines and their production efficiency has been previously discussed. In this study, we investigated whether treatment with forskolin (FSK), an adenylyl cyclase activator, affected the output of a cell-based influenza vaccine. We found that FSK increased the propagation of three influenza virus subtypes (A/H1N1/California/4/09, A/H3N2/Mississippi/1/85, and B/Shandong/7/97) in Madin-Darby canine kidney (MDCK) cells. Interestingly, FSK suppressed the growth of MDCK cells. This effect could be a result of protein kinase A (PKA)-Src axis activation, which downregulates extracellular signal-regulated kinase (ERK)1/2 activity and delays cell cycle progression from G1 to S. This delay in cell growth might benefit the binding and entry of the influenza virus in the early stages of viral replication. In contrast, FSK dramatically upregulated ERK1/2 activity via the cAMP-PKA-Raf-1 axis at a late stage of viral replication. Thus, increased ERK1/2 activity might contribute to increased viral ribonucleoprotein export and influenza virus propagation. The increase in viral titer induced by FSK could be explained by the action of cAMP in assisting the entry and binding of the influenza virus. Therefore, FSK addition to cell culture systems could help increase the production efficiency of cell-based vaccines against the influenza virus.

• The Journal of Korean Academic Society of Nursing Education
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• v.17 no.2
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• pp.277-286
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• 2011

Purpose: This study examined levels of stress and adherence to self care guidelines in elementary and middle school students who were infected with the influenza A (H1N1) virus in 2009. Method: A total of 649 students from J city participated in the survey. Stress was measured with the Impact of Event Scale-Revised which was developed by Weiss and Marmar (1997) and translated by Eun and colleagues (2005). Adherence to self care guidelines was measured with the scale developed by the authors based on the self care recommendations from Korea Centers for Disease Control and Prevention. Result: Levels of stress and adherence to self care guidelines were higher in elementary school students. However, the severity of participants' stress was less than moderate. The adherence level was significantly different depending on status of taking an antiviral agent, health education and self care education regarding the virus infection. Conclusion: Findings suggest that effects of health education under the national crisis situation due to influenza A (H1N1) virus pandemic were helpful. More in-depth study is needed to understand and to improve middle school students' self care behaviors.

• Journal of Veterinary Science
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• v.23 no.2
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• pp.24.1-24.10
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• 2022

Background: Small interfering RNA technology has been considered a prospective alternative antiviral treatment using gene silencing against influenza viruses with high mutations rates. On the other hand, there are no reports on its effectiveness against the highly pathogenic avian influenza H5N1 virus isolated from Indonesia. Objectives: The main objective of this study was to improve the siRNA design based on the nucleoprotein gene (siRNA-NP) for the Indonesian H5N1 virus. Methods: The effectiveness of these siRNA-NPs (NP672, NP1433, and NP1469) was analyzed in vitro in Marbin-Darby canine kidney cells. Results: The siRNA-NP672 caused the largest decrease in viral production and gene expression at 24, 48, and 72 h post-infection compared to the other siRNA-NPs. Moreover, three serial passages of the H5N1 virus in the presence of siRNA-NP672 did not induce any mutations within the nucleoprotein gene. Conclusions: These findings suggest that siRNA-NP672 can provide better protection against the Indonesian strain of the H5N1 virus.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.512-516
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• 2008

To search for anit-H5N1 influenza virus agent, the anti-viral activity of methanol and aqueous extracts from thirty medicinal plants were examined in this study. The plant material (30 g) was extracted with methanol (300 mL) for 24 hr at room temperature. Methanol extracts were filtered and evaporated, then freeze-dried. Aqueous extracts were prepared with dried plant material (30 g) and hot distilled water (300 mL). After 3 hr, the aqueous extracts were filtered and evaporated, then lyophilized. Extracts prepared from different plants were tested the antiviral activity against influenza viruses [A/vietnam/1194/04 (H5N1)-NIBRG-14] using the hemagglutination (HA) assay. Among the test plants, Asarum sieboldii was found to be a potent inhibitor of H5N1 influenza virus in MDCK cell culture. Virus titers were 7 log, whereas with methanol extract of Asarum sieboldii for 48 hr titers were 3 log, indicating that methanol extract of Asarum sieboldii inhibited the H5N1 influenza viruses from the infected cells.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.340-344
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• 2007

Avian influenza viruses cause a considerable threat to humans and animals. In this study, we investigated whether alkaline disinfectant solution can inactivate H5N1, H3N2, H6N1, and H9N2 subtypes of avian influenza virus. When H5N1, H3N2, H6N1, and H9N2 avian influenza viruses were treated with alkaline solution diluted with PBS (pH 7.2) prior to infection into MDCK cells, alkaline disinfectant solution (at dilutions up to $10^{-2}$) completely inactivated all avian influenza subtypes tested. To confirm the inactivation of avian influenza viruses by alkaline disinfectant solution, we used an immunofluorescence assay with influenza A anti-nucleoprotein antibody and FITC-labeled secondary antibody to stain MDCK cells infected with avian H9N2 influenza viruses. No staining was observed in MDCK rells infected with H9N2 viruses that were pre-treated with a $10^{-2}$ dilution of alkaline disinfectant solution, while strong staining was observed in MDCK cells infected with H9N2 viruses without pre-treatment. Our results indicate that alkaline solution could help to control avian influenza viruses including the highly pathogenic H5N1 subtype.

• Clinical and Experimental Pediatrics
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• v.54 no.10
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• pp.405-408
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• 2011

Purpose: In autumn 2009, the swine-origin influenza A (H1N1) virus spread throughout South Korea. The aims of this study were to determine the clinical characteristics of children infected by the 2009 H1N1 influenza A virus, and to compare the rapid antigen and realtime polymerase chain reaction (PCR) tests. Methods: We conducted a retrospective review of patients ${\geq}18$ years of age who presented to Soonchunhyang University Hospital in Seoul with respiratory symptoms, including fever, between September 2009 and January 2010. A real-time PCR test was used to definitively diagnose 2009 H1N1 influenza A infection. Medical records of confirmed cases were reviewed for sex, age, and the time of infection. The decision to perform rapid antigen testing was not influenced by clinical conditions, but by individual factors such as economic conditions. Its sensitivity and specificity were evaluated compared to real-time PCR test results. Results: In total, 934 patients tested positive for H1N1 by real-time PCR. The highest number of patients (48.9%) was diagnosed in November. Most patients (48.2%) were aged between 6 and 10 years. Compared with the H1N1 real-time PCR test results, the rapid antigen test showed 22% sensitivity and 83% specificity. Seventy-eight patients were hospitalized for H1N1 influenza A virus infection, and fever was the most common symptom (97.4%). Conclusion: For diagnosis of 2009 H1N1 influenza A virus infection, the rapid antigen test was inferior to the real-time PCR test in both sensitivity and specificity. This outcome suggests that the rapid antigen test is inappropriate for screening.

• Journal of Life Science
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• v.9 no.5
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• pp.570-574
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• 1999

Investigate the epidemics for influenza outbreaks. The outbreak pattern of the internal patients housed in the 10 designated hospitals was monitered to investigate and the characteristics of the virus isolates are as follows. 232 strains of influenza virus was isolated from the oral specimen of 1,320 respiratory disease patients in Pusan from Oct. 1998 to Jun. 1999. Among these isolates, 222 strains were A-type and the rest were B-type. The outbreak pattern for sex-and age-groups is as follows. The male outbreak was similar to the female outbreak: male outbreak, 47.4% and female outbreak, 52.5%. Most of the patients were less than 10 years old. The monthly influenza outbreak was consistent from Dec. 1998 to Apr. 1999. and The 113 strains from the A-type isolates were A/ Sydney/05/97(H3N2)-like, the 109 strains were A/Beijing/262/95(H1N1)-like, and all of the 10 B-type isolates were B/Harbin/07/94-like.

• Pediatric Infection and Vaccine
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• v.19 no.3
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• pp.149-156
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• 2012

Purpose : We conducted a prospective comparative clinical study to determine the field efficacy of the 2010-2011 influenza vaccines [Influenza virus strains; A/California/7/2009 (H1N1), A/Perth/16/2009 (H3N2), B/Brisbane/60/2008] in healthy Korean children under 18 years of age. Methods : In this study, we enrolled subjects aged between 6 months and 18 years and divided them into 2 study groups: a group who received the influenza vaccines (407 subjects), and a control group who did not receive the influenza vaccines (230 subjects). Ours was a multicenter study that involved 7 hospitals, including the Korea Cancer Center Hospital. The study was conducted between September 2010 and February 2011. We collected nasal wash or throat swab samples from subjects who presented with acute febrile respiratory or influenza-like illnesses at the hospital. We used PCR to confirm the presence of the influenza virus in the respiratory samples and characterize the virus type. Results : In this study, we collected 22 respiratory samples from the influenza-vaccinated group and found 3 cases of influenza virus infection. Similarly, we collected 21 samples from the control group and found 12 cases of influenza virus infection among 10 subjects during the study period. We determined the field efficacy of the 2010-2011 seasonal influenza vaccines to be 83.2% in healthy Korean children and adolescents. Conclusion : In this study, we determined the field efficacy of the 2010-2011 seasonal influenza vaccines in healthy Korean children and adolescents. We found that the field efficacy of 2010-2011 seasonal influenza vaccines was adequate.