• Toxicological Research
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• v.17
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• pp.157-166
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• 2001

Almost all currently available retroviral vectors based on murine leukemia virus (MLV) contain one or more viral coding sequences. Because these sequences are also present in the packaging genome, it has been suggested that homologous recombination may occur between the same nucleotide sequence in the packaging genome and the vector, resulting in the production of replication competent retrovirus (RCR). Up until now, it has been difficult to completely remove viral coding sequences since some were thought to be involved in the optimum function of the retroviral vector. For example, the gag coding sequence present in almost all available retroviral vectors has been believed to be necessary for efficient viral packaging, while the pol coding sequence present in the highly efficient vector MFG has been thought to be involved in achieving the high levels of gene expression. However, we have now developed a series of retroviral vectors that are absent of any retroviral coding sequences but produce even higher levels of gene expression without compromising viral titer. In these vectors, the intron and exon sequences from heterologous cellular or viral genes are present. When compared to the well known MLV-based vectors, some of these newly developed vectors have been shown to produce significantly higher levels of gene expression for a longer period. In an experimental system that can maximize the production of RCR, our newly constructed vectors produced an absence of RCR. These vectors should prove to be safer than other currently available retroviral vectors containing one or more viral coding sequences.

• Korean Journal of Veterinary Service
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• v.42 no.4
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• pp.285-288
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• 2019

Foot-and-mouth disease (FMD) causes economic problems in livestock industry because of fast spread and inducing low productivity. FMD outbreaks occurred in South Korea over the period from 2000 to 2019. Vaccination is the most practical and effective means of controlling or preventing these outbreaks, and a national vaccination policy has been in place for all FMD-susceptible animals since 2010. To prevent and control of FMD, South Korea has been using vaccines imported from the United Kingdom, Argentina, and Russia. The Animal and Plant Quarantine Agency of South Korea oversees continuous quality control of imported FMD vaccines. FMD vaccines were evaluated characteristics, sterility, pH, inactivation, safety, potency test by Korean FMD vaccine standard assay (Test for National Lot Release). The 6 company vaccines (A~F) were used Test for National Lot Release by each method. We evaluated quality of each FMD vaccine from 2015 to 2019. All batch of vaccine showed good quality control and were passed the Test for National Lot Release. The serotypes of vaccine are increasingly changing to multiple vaccine because the FMD was outbreak by various serotype virus in South Korea. Furthermore, this data may be useful as a basis for ensuring the quality of FMD vaccines and for base data to manage them. Additional study is required to simple approach for rapid evaluation of quality and antigen content identification in vaccines.

• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.96-101
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• 2010

Norovirus, which causes gastroenteritis in humans, is an important food-borne pathogen worldwide. In an effort to discover an antiviral substance against norovirus, extracts from several seaweeds were evaluated for antiviral activity against feline calicivirus (FCV), which was used as a surrogate. The methanolic extract of Undaria pinnatifida exhibited the most significant antiviral activity and virucidal efficacy against FCV. The concentrations of the extract that reduced viral replication by 50% ($EC_{50}$) and resulted in the death of 50% of the host cells ($CC_{50}$) were 0.05 mg/mL and 1.02 mg/mL, respectively. The selectivity index, calculated from the ratio of the $CC_{50}$ and $EC_{50}$ was 20.4. No FCV infection of host cells occurred following a 1-h incubation in the presence of 12.50 mg/mL U. pinnatifida extract, indicating that the virus was completely inactivated by the extract treatment. The results obtained in this study will contribute to the development of a natural antiviral substance that will prevent food-borne disease caused by norovirus.

• BMB Reports
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• v.53 no.4
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• pp.191-205
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• 2020

The unexpected pandemic set off by the novel coronavirus 2019 (COVID-19) has caused severe panic among people worldwide. COVID-19 has created havoc, and scientists and physicians are urged to test the efficiency and safety of drugs used to treat this disease. In such a pandemic situation, various steps have been taken by the government to control and prevent the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). This pandemic situation has forced scientists to rework strategies to combat infectious diseases through drugs, treatment, and control measures. COVID-19 treatment requires both limiting viral multiplication and neutralizing tissue damage induced by an inappropriate immune reaction. Currently, various diagnostic kits to test for COVID-19 are available, and repurposing therapeutics for COVID-19 has shown to be clinically effective. As the global demand for diagnostics and therapeutics continues to rise, it is essential to rapidly develop various algorithms to successfully identify and contain the virus. This review discusses the updates on specimens/samples, recent efficient diagnostics, and therapeutic approaches to control the disease and repurposed drugs mainly focusing on chloroquine/hydroxychloroquine and convalescent plasma (CP). More research is required for further understanding of the influence of diagnostics and therapeutic approaches to develop vaccines and drugs for COVID-19.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.121-124
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• 2002

This work was initiated to develope a recombinant oral poliovaccine (OPV), which is highly advanced in safety (minimizing VAPP) by introducing Type 2,3 poliovirus epitopes into our RPS-Vax system. We have introduced several potential vaccine epitopes of poliovirus Type 2, and 3 into RPS-Vax system, resulting in production of recombinant polioviruses. Any of these chimeric viruses, however, were not detected for their foreign gene expression by serotype-specific mouse antiserum. We have designed several folding units to stabilize the introduced vaccine protein and attached short epitope-concatamer or epitope-multimer to them, followed by production of chimeric viruses. Only those who have an HIV-1 Tat-mediated folding unit were nicely detected for the introduced foreign proteins by anti-Tat antiserum and type-specific peptide-induced antisera. Nevertheless, introduced epitopes were not detected in Western blot experiment with each serotype-specific antiserum. None of the mice inoculated with these chimeric viruses showed preventative immunity when challenged with Lansing and Leon wildtype 2 and 3 poliovirus, and the antiserum did not show neutralizing capacity in vitro. Conformational epitope covering B/C loop region of type 2 and 3 were newly designed by computer modeling, and introduced into the RPS-Vax vector system, followed by production of chimeric viruses. Introduced epitope regions were nicely detected by anti-Tag23 mAb or peptide antibody, but still not detected by poliovirus antiserum. Nevertheless, neutralizing antibody was detected in the Tg-PVR mice even when inoculated once with these chimeric viruses. Also, the immunized mice showed perfect preventative immunity against the wild Type poliovirus Lancing or Leon. When boosted appropriately, those chimeric virus-inoculated Tg-PVR mice produced equivalent amounts of neutralizing antibody to those in Sabin 2/3-immunized mice. These data strongly suggest that our recombinant poliovirus (RPS-PV2 and RPS-PV3) can be used as a safe and effective rec-OPV instead of any preexisting poliovaccine.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.1
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• pp.51-61
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• 2011

A smartphone is a mobile phone that offers more advanced computing ability and connectivity than a contemporary basic feature phone. Unlike feature phone, a smartphone allows the user to install and run more advanced applications based on a specific platform. Smartphones run complete operating system software providing a platform for application developers. A smartphone will become the default computing method for many point activities in the not-too-distant future, such as e-mail, online shopping, gaming, and even video entertainment. For smartphone that contains sensitive information and access the Internet, security is a major issue. In the 1980s, security issues were hardly noticed; however, security is a major issue for users today, which includes smart phones. Because security is much more difficult to address once deployment and implementation are underway, it should be considered from the beginning. Recently our government recognized the importance of smartphone security and published several safety tips for using the smartphone. However, theses tips are user-oriented measures. Maintaining the security of a smartphone involves the active participation of the user. Although it is a important users understand and take full advantage of the facilities afforded by smarphone, it is more important developers distribute the secure smartphone application through the market. In this paper we describe some scenarios in which user is invaded his/her privacy by smartphone stolen, lost, misplaced or infected with virus. Then we suggest the security considerations for securing smartphone applications in respect with developers. We also suggest the methods applying domestic encryption algorithms such as SEED, HIGHT and ARIA in developing secure applications. This suggested security considerations may be used by developers as well as users (especially organizations) interested in enhancing security to related security incidents for current and future use of smartphones.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.10a
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• pp.31-50
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• 2000

Almost all currently available retroviral vectors based on murine leukemia virus (MLV) contain one or more viral coding sequences Because these sequences are also present in the packaging genome, it has been suggested that homologous recombination may occur between the same nucleotide sequence in the packaging genome and the vector, resulting in the production of replication competent retrovirus (RCR). Up until now, it has been difficult to completely remove viral coding sequences since some were thought to be involved in the optimum function of the retroviral vector. For example, the gag coding sequence present in almost all available retroviral vectors has been believed to be necessary for efficient viral packaging, while the pol coding sequence present in the highly efficient vector MFG has been thought to be involved in achieving the high levels of gene e(pression. However, we have now developed a series of reroviral vectors that are absent of any retroviral coding sequences but produce even higher levels of gene expression without compromising viral titer. In these vectors the intron and exon sequences from heterologous cellular or viral genes are present, When compared to the well blown MLV-based vectors, some of these newly developed vectors have been shown to produce significantly higher levels of gene expression for a longer period. In an experimental system that can maximize the production of RCR, our newly constructed vectors produced an absence of RCR. These vectors should prove to be safer than other currently available retroviral vectors containing one or more viral coding sequences

• Journal of Environmental Health Sciences
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• v.33 no.3
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• pp.184-189
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• 2007

Pathogenic microbial foodborne disease outbreaks (PMFBDOs) have increased in many countries, the boom in food service establishment is not matched by effective food safety and control. In this study, we investigated the current state and the epidemic aspects of FBDOs in Korea and Japan. In Korea, the average prevalence rate of foodborne disease (FBD) was 15.0 per 100,000 population and cases per outbreak of FBD was 57.0. During the same period in Japan, the prevalence rate showed an average of 24.9, and the cases per outbreak were 16. When both prevalence rate and cases per outbreak were compared, the prevalence rate in Japan was much higher than that in Korea (p<0.01). However, average cases per outbreak of FBD in Japan were much lower than those in Korea (p<0.01). In Korea, outbreaks of FBDs were more common in spring (p<0.01), while in Japan, more frequent in summer and winter (p<0.01). Outbreaks of FBD occurred largely through restaurant and school foods (32.0% and 27.5%) in Korea. In Japan, the proportion of the outbreak cases in the restaurant and home were 23.7% and 12.1%, and cases of unknown causes of FBDs were 48.2%, respectively. Bacteria were the major causes of infection in both countries. The prevalence of PMFBDOs by Salmonella spp. Vibrio parahemolyticus and Staphylococcus aureus were much higher in Korea, while those by Camphylobacter spp. and SRSV were more common in Japan. The causes by virus were more frequent in Japan (13.7%) than in Korea (7.7%). The prevalence of FBDs in Korea and Japan showed characteristic differences, especially in the PMFBDOs due to such factors as geography, climate, culture, diet and food management.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.949-964
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• 2012

Our PC have been under constant threat of malicious codes and viruses today. As many new ways of cyber attacks are being developed, such as zero-day-attack, nobody's PC is guaranteed to be safe from the attacks. In case where a user uses the existing verification protocol on a unsecured PC, the user's verification information may well be threatened by sniffing or man-in-the-middle attack. Especially, deadly attacks like memory hacking would give hard time for users to even recognize any symptom of virus infection. Therefore, this paper designs secured QR-Login user verification protocol for smart devices that are ready to communicate with QR-Code and proposes a way to keep critical data safe when using the internet. This way, user would be able to safeguard his/her critical data even when under attack by unknown attacks and safely carry out extremely sensitive task, like financial trading, on the device.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.6
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• pp.463-472
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• 2020

Direct reprogramming, also known as a trans-differentiation, is a technique to allow mature cells to be converted into other types of cells without inducing a pluripotent stage. It has been suggested as a major strategy to acquire the desired type of cells in cell-based therapies to repair damaged tissues. Studies related to switching the fate of cells through epigenetic modification have been progressing and they can bypass safety issues raised by the virus-based transfection methods. In this study, a protocol was established to directly convert fully differentiated fibroblasts into diverse mesenchymal-lineage cells, such as osteoblasts, adipocytes, chondrocytes, and ectodermal cells, including neurons, by means of DNA demethylation, immediately followed by culturing in various differentiating media. First, 24 h exposure of 5-azacytidine (5-aza-CN), a well-characterized DNA methyl transferase inhibitor, to NIH-3T3 murine fibroblast cells induced the expression of stem-cell markers, that is, increasing cell plasticity. Next, 5-aza-CN treated fibroblasts were cultured in osteogenic, adipogenic, chondrogenic, and neurogenic media with or without bone morphogenetic protein 2 for a designated period. Differentiation of each desired type of cell was verified by quantitative reverse transcriptase-polymerase chain reaction/western blot assays for appropriate marker expression and by various staining methods, such as alkaline phosphatase/alizarin red S/oil red O/alcian blue. These proposed procedures allowed easier acquisition of the desired cells without any transgenic modification, using direct reprogramming technology, and thus may help make it more available in the clinical fields of regenerative medicine.