• IMMUNE NETWORK
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• v.21 no.1
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• pp.8.1-8.17
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• 2021

The global crisis caused by the coronavirus disease 2019 (COVID-19) led to the most significant economic loss and human deaths after World War II. The pathogen causing this disease is a novel virus called the severe acute respiratory syndrome coronavirus 2 (SARSCoV-2). As of December 2020, there have been 80.2 million confirmed patients, and the mortality rate is known as 2.16% globally. A strategy to protect a host from SARS-CoV-2 is by suppressing intracellular viral replication or preventing viral entry. We focused on the spike glycoprotein that is responsible for the entry of SARS-CoV-2 into the host cell. Recently, the US Food and Drug Administration/EU Medicines Agency authorized a vaccine and antibody to treat COVID-19 patients by emergency use approval in the absence of long-term clinical trials. Both commercial and academic efforts to develop preventive and therapeutic agents continue all over the world. In this review, we present a perspective on current reports about the spike glycoprotein of SARS-CoV-2 as a therapeutic target.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.144-147
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• 2014

It was intended to closely examine an effect that a change in the concentration of culture medium had on the potato(Solanum tuberosum L.) plantlet growth in the microponic system so as to mass-produce the virus-free plant of new variety 'Saebong' for potato processing. The adjusted concentration of potato culture medium was 0.2, 0.6, 1.0, 1.4, 1.8, and $14.0dS{\cdot}m^{-1}$. And potato seedling was cut into pieces of 1.5 cm in length, which included 2 growth points and leaves. And each was explanted in glass vial of 50 mL. And experiments were carried out twice for 18 days or 21days. Culture medium of 2ml was put in the container respectively. And 1 mL was added after 10 days. And in terms of cultivation environment, the experiment was carried out at the day length of 16 hours at the temperature of $23{\pm}1^{\circ}C$ under the white LED light of $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The concentration of culture medium in the experiment I was EC 0.2, 1.0, $14dS{\cdot}m^{-1}$ and was adjusted to 0.6, 1.0, 1.4, $1.8dS{\cdot}m^{-1}$ in the experiment II. The results showed that the survival rate of plantlet was 90% at $0.2dS^2m^{-1}$, 100% at $0.6dS^2m^{-1}$, 100% at $1.0dS^2m^{-1}$. 0% at $1.4dS{\cdot}m^{-1}$, 0% at $1.8dS{\cdot}m^{-1}$. and 0% at $14.0dS{\cdot}m^{-1}$ after 7 days. With regard to the explanted potato seedling, in case of the treatment where the electrical conductivity of culture medium was adjusted to $1.0dS{\cdot}m^{-1}$, root developed 2 days after transplantation. And the plantlet vigorously grew into strong plant that had 7 leaves, length of 5cm, and fresh weight of 0.5 g after 18 days. In case of the treatment where the concentration of culture medium was adjusted to $0.6dS{\cdot}m^{-1}$, the root plantlets developed 4 days after transplantation. And those grew into plant that had 7 leaves and fresh weight of 0.2 g after 21 days. Therefore, we found that it is effective to control potato culture medium by adjusting its electrical conductivity to $0.6{\sim}1.0dS{\cdot}m^{-1}$ for the mass production of virus-free potato seedling in the microponic system.

• Korean Journal of Veterinary Research
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• v.25 no.1
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• pp.7-17
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• 1985

Many investigators have been pursuing various attempts so far to produce hepatitis B surface antigen(HBsAg) vaccines using the techniques such as isolation from plasma of chronic HBsAg carrier, recombinant DNA technique or preparation of synthetic peptides specific for immunogenic determinants. Hepatitis B virus can not grow on any cell lines by the tissue culture technique at the present time. The plasma of chronic HBsAg carrier is expensive and its source is limited. The HBsAg from the recombinant DNA technique gave still very low yield. Another approach, therefore, has been initiated to develop a synthetic hepatitis B virus vaccine. The possible use of several distinct synthetic vaccines in prophylaxis can be facilitated by availability of full synthetic immunogens. Peptides synthesized for potential application as antiviral vaccines have been mostly tested in the form of conjugates with carrier proteins, although the free synthetic peptide can be immunogenic. To understand basic knowledges on the antigenicity and immunogenicity of a synthetic peptide specific for major immunogenic determinant of HBsAg, a nonapeptide, $H_2N^{139}Cys-Thr-Lys-Pro-Thr-Asp-Gly-^{146}Asn-Aba$ COOH, which corresponds to HBsAg amino acid residues 139 to 147, was synthesized by the Merrifield's solid-phase method with a slight modification. The antigenicity and immunogenicity of this specific synthetic peptide were examined comparing with purified plasma-derived natural HBsAg. The results obtained are as follows; 1. The peptide synthesized showed the identical amino acid composition to the theoretical value. The degree of purification and molecular weight were acertained by methods of high performance liquid chromatography and mass spectrometry. 2. Using m-maleimidobenzoyl-N-hydroxysuccinimide ester as a conjugating agent, the synthetic peptide was conjugated to rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin. Their conjugation yields were 8.3, 9.5, 15.8, 13.5, and 11.2%, respectively. 3. The natural HBsAg was purified from plasma of chronic HBsAg carrier. By the electron microscopic observation of the purified natural HBsAg preparation, no Dane particles were observed and the preparation showed negative DNA polymerase activity. 4. Antigenicity of the synthetic peptide and the plasma-derived natural HBsAg was determined by competition radioimmunoassay using $^{125}I$-natural HBsAg. Their 50% inhibitions appeared as $90{\mu}g/ml$ and $0.12{\mu}g/ml$ for the synthetic peptide and the natural HBsAg, respectively. This indicates that the former was about 750-fold less antigenic than the latter. 5. Immunogenicity of the synthetic peptide was determined by administering the peptide-carrier conjugates into rabbits with and without Freund's complete adjuvant. Regardless the carrier proteins and adjuvant, positive immune responses to the synthetic peptide were observed. The higher antibody titers, however, were shown in the groups administered with Freund's complete adjuvant. 6. Immunizing dose 50% in mice of the various peptide-carrier conjugates was 5.47, 6.00, 65.16, 31.25 and $13.03{\mu}g/dose$ for rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin, respectively, while the natural HBsAg showed $0.65{\mu}g/dose$. 7. It was postulated that homologous proteins prefer to heterologous ones as the carriers.

• Pediatric Infection and Vaccine
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• v.19 no.3
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• pp.121-130
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• 2012

Purpose : The purpose of this study is to investigate clinical features and causative organisms in febrile infants younger than three months, to help identification of high risk patients for serious bacterial infection (SBI). Methods : A total of 313 febrile infants younger than three months, who had visited Seoul National University Children's Hospital from January 2008 to December 2010 were included. Clinical features, laboratory findings, causative organisms, and risk factors of SBI were analyzed by retrospective chart review. Causative bacterial or viral pathogens were identified by gram stain and cultures, rapid antigen tests, or the polymerase chain reaction from clinically reliable sources. Results : Among 313 infants, etiologic organisms were identified in 127 cases (40.6%). Among 39 cases of bacterial infections, Escherichia coli (66.7%) and Streptococcus agalactiae (12.8%) were common. Enterovirus (33.7%), respiratory syncytial virus (19.8%), and rhinovirus (18.8%) were frequently detected in 88 cases of viral infection. Patients with SBI (39 cases) showed significantly higher values of the white blood cell count ($14,473{\pm}6,824/mm^3$ vs. $11,254{\pm}5,775/mm^3$, P=0.002) and the C-reactive protein ($6.32{\pm}8.51mg/L$ vs. $1.28{\pm}2.35mg/L$, P<0.001) than those without SBI (274 cases). The clinical risk factors for SBI were the male (OR 3.7, 95% CI 1.5-8.9), the presence of neurologic symptoms (OR 4.8, 95% CI 1.4-16.8), and the absence of family members with respiratory symptoms (OR 3.6, 95% CI 1.2-11.3). Conclusion : This study identified common pathogens and risk factors for SBI in febrile infants younger than three months. These findings may be useful to guide management of febrile young infants.

• Information Systems Review
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• v.12 no.1
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• pp.23-42
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• 2010

Although organizations are given various benefits with information technologies, they sometimes have suffered fatal damages due to information security incidents now such as computer virus, hacking, counterfeiting, plagiarizing, etc. The fundamentalcauses of information security incidents are closely related to individuals who do not comply with information security policy or rules. The spontaneous self-control of individuals and monitoring for individuals could be the most essential solution for the ongoing observance of information security policy. Thus, the purpose of this study is to analyze effects of punishment and ethics training on compliance of information security policy of individuals in organizations, to determine individual divide among security propensity depending on organization types, and to find the more fundamental solution which leads change of organizational members’ behaviors and self-control. Regardless of the type of organizations, the results of the study suggest that there exist positive effects of punishment and ethics training in all types of organization on compliance of information security rules or regulations. A member of unitary form organization has higher cognition of punishment than a member's cognition of the multi-divisional form organization, while relatively lower awareness of ethics training. Also, a member of public organization has higher awareness of ethics training than a member’s awareness of private organization, while lower cognition of punishment. Finally, the result shows that punishment and ethics training may be major factors which affect information security. It also suggests that organizational security managers have to understand and consider organization member’s propensity relying on organization form and organization characteristics for establishment and enforcement of information security policy.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.283-290
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• 2008

Baculoviruses have been used to control some serious lepidopteran pests. However, their narrow target insect spectrum and slow efficacy are main limitations to be used in various applications. This study introduces a technique to overcome these limitations by inhibiting insect immune defence to enhance the viral pathogenicity. Polydnaviruses are an insect DNA virus group and symbiotic to some ichneumonid and braconid endoparasitoids. Cotesia plutellae bracovirus (CpBV) is a braconid polydnavirus and encodes several immunosuppressive genes. We selected seven CpBV genes and recombined them to wild type Autographa California multiple nucleopolyhedrovirus (AcNPV). A bioassay of these seven recombinants indicated that most recombinants had similar or superior efficacy to wild type AcNPV against beet armyworm, Spodoptera exigua, and diamondback moth, Plutella xylostella. Recombinant AcNPV with CpBV-ELP was the most potent in terms of lethal time by shortening more than 2 days compared to wild type AcNPV. This recombinant was further proved in its dose-dependent pathogenicity and its efficacy by spray application on S. exigua infesting cabbage cultivated in pots. We discussed the efficacy of CpBV-ELP recombinant AcNPV in terms of suppressing antiviral activity of target insects.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.111-116
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• 2003

Turnip mosaic Potyvirus (TuMV) and Ribgrass mosaic Tobamovirus (RMV) are major viruses infecting crucifer crops in Korea. RMV-FG22 was isolated from oriental cabbage. TuMV isolates were TuMV-CA7 from oriental cabbage, TuMV-TU and TuMV-TU2 from turnip, TuMV-RA from rape, TuMV-ST from stock, and TuMV-R9 from radish. The six isolates of TuMV were classified by symptom expression in inbred lines of crucifers. TuMV-CA7 and TuMV-TU isolates infected mostly oriental cabbages; TuMV-ST, TuMV-TU2, and TuMV-R9 infected radishes; and TuMV-RA infected both oriental cabbages and radishes. Crops used in six combinations of mixed infections were 'Tambok' cultivar resistant to TuMV,'SSD63' susceptible inbred line of oriental cabbage, pure line of leaf mustard, and‘Daeburyungyeorum’cultivar of radish. External symptoms in 'Tambok' and radish by each of the six single infections of TuMV showed similar results by bioassay. Synergistic response of necrotic death occurred within 1 week after inoculation in all combinations mixed with TuMV and RMV-FG22 on leaf mustard. In oriental cabbage 'SSD63' , synergism of necrosis occurred in four TuMV isolates, but not in TuMV-ST and TuMV-R9. In oriental cabbage 'Tambok' , synergism was expressed only in two combinations of RMV-FG22+TuMV-CA7 and RMV-FG22+TuV-TU, but other combinations had the same symptoms produced by RM-FG22. In radish‘Daeburyungyeorum’, only mild mosaic symptoms were induced by combinations of RMV-FG22+TuMV-CA7, RMV-FG22+TuMV-TU, RMV-FG22+TuMV-RA, and RMV-FG22+TuMV-R9. Mosaic and severe mosaic were induced in combinations of RMV-FG22 +TuMV-TU2 and RMV-FG22+TuMV-ST, respectively.

• Journal of Preventive Medicine and Public Health
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• v.37 no.4
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• pp.337-344
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• 2004

Objectives : This study was performed to determine the incidence density and the prevalence of sero-positive hepatitis C from 1999 to 2002 among adults aged 20 and over residing in Seoul and the Gyeonggi province. Method : The data for period was obtained from 114,635 adults, residing in Seoul or the Gyeonggi province, who had undertaken comprehensive health screening tests from Jan 1999 to Dec 2002 in a University hospital in Seoul. Among them, subjects with sero-negative status against hepatitis C were selected (21,408 in 1999, 28,830 in 2000) and then followed up until Dec 2002 to determine the incidence of hepatitis C during this period. The serum was tested with the immunoradiometric assay (IRMA) which uses third generation HCV antibody. Age adjusted rates were estimated by direct standardization using a reference population of 2000 aged from 20 to 80 years. Results : The prevalence of anti-HCV from 1999 to 2002 was 2.1 per 1000 persons(95% CI $1.8{\sim}2.4$). Male showed 1.7 per 1000 persons (95% CI $1.4{\sim}2.1$), while female showed 2.7 per 1000 persons(95% CI $2.2{\sim}3.2$). Age?sex adjusted rate showed 2.8 per 1000 persons (95% CI $2.64{\sim}2.96$), which is lower than the results of some previous study. The prevalence showed a significantly increasing pattern with age both in males and females (p<0.05). The incidence density of anti-HCV among the population aged 20 and over was 1.1 per 104 person-years at risk (95% CI $0.6{\sim}2.4$); 1.2 (95% CI $0.6{\sim}2.7$) for males and 0.8 (95% CI $0.6{\sim}4.2$) for females. Age adjusted incidence density was 2.91 per 104 person-years at risk (95% CI $2.43{\sim}3.38$) for those aged 20 and over. It showed an increasing pattern with age (p<0.05), especially for those age over 50 years. Conclusion : The study subjects for this study were supposedly healthier than the general population so the prevalence and incidence for the general population are thought to be higher than the results of the present study.

• The Journal of Korean Society for Radiation Therapy
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• v.21 no.2
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• pp.75-82
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• 2009

Purpose: Measure the ozone level in the treatment room while treating a patient so want to know the degree of contamination caused by ozone occurrence. Materials and Methods: Use the linear accelerator (Clinac 21EX, Varian, USA) with the ozone meter (series-200, aeroQual, New Zealand) and water phantom (Wellhofer, IBA, Germany) is irradiated the radiation so that measured the ozone generation level according to MU, dose-rate, SSD, field size, energy, delay time and put the ozone meter in the treatment room actually while treating a patient so measured the daily ozone level variation. Results: While irradiating the radiation, degree of ozone contamination wasn't affected by the energy but mostly in case of electron beam, ozone level was higher than photon beam. The higher dose-rate (0.016~0.025 ppm/hr), the farther SSD (0.018~0.030 ppm/hr), the wider field sizes (0.016~0.025 ppm/hr), the more MU (0.018~0.046 ppm/hr), it occurred high ozone level. Ozone decrement according to delay time changed the background level (0.016 ppm/hr) after elapsed time of 10 minutes from irradiating radiation. And daily ozone occurrence level in the treatment room was below ozone standard level 0.1 ppm/hr (average:0.06 ppm/8 hr) but it could confirm that ozone generation level was included the level (max:0.038 ppm/hr) above 0.02 ppm/hr which patient could perceive. Conclusion: Through ozone level according to variation of certain conditions, actually in the treatment room ozone generation level didn't damaged to patients or workers. Commonly peoples think that ozone was harmful gas but it thought that small amount of ozone generation level while treating a patient was beneficial in the treatment room through air purge action of pathogenic germ or virus sterilization.

• Pediatric Infection and Vaccine
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• v.10 no.2
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• pp.186-192
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• 2003

Purposes : Recently, acute gastroenteritis broke out among the neonates transferred from postpartum care centers located in Seoul, and Gyeounggi area. Thus, we researched the cause, progress and characters of the disease by analyzing the cases from 9 hospitals in Seoul and Gyeounggi area. Methods : We conducted retrospective study of 33 neonates transferred from postpartum care centers from October 2001 to July 2002 : we divided the neonates into 2 groups. The severe group had any of following 5 conditions : blood pH <7.20, respiratory difficulty, mechanical ventilation, shock, and disseminated intravascular coagulation. And the rest were classified into the moderate group. Results : The severe group was significantly more aged than the moderate group(P= 0.005). Weight loss was significantly severe in the severe group(P=0.0512). In blood gas analysis, bicarbonate was less in the severe group than the moderate group(P=0.032). In the virus examination, rotavirus was detected in 7 cases, and astrovirus was detected in 1 case. In the severe group, 4 neonates were dead. Conclusion : In acute gastroenteritis of neonates, early diagnosis and treatment are important. Thus, the legislation of postpartum care center is needed, and the medical specialists should be stationed in postpartum care center. We assume that the severe group had severe conditions because they were treated comparatively late. However, to find out the cause of the disease and to cope with it, the nationwide epidemiologic study on acute gastrenteritis of neonates is needed.