• Journal of Microbiology and Biotechnology
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• v.12 no.6
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• pp.882-889
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• 2002

Hantaan vims production, using human immortalized retina cell (PER. C6), was investigated to develop an inactivated virus vaccine. To infect Hantaan virus into PER. C6, two infection methods (medium-to-cell and cell-to-cell) were tried, and IFA results showed that the cell-to-cell infection method was very useful for producing Hantaan virus-infected PER, C6. Hantaan virus production was significantly affected by the growth rate of PER. C6 and the content of FBS in medium. Higher specific growth rate of infected PER. C6 and lower FBS content induced higher production of Hantaan virus. The inactivated human cell-culture vaccines with various EIA titers were prepared, their antibody responses were compared with those of inactivated suckling mouse brain vaccines ($Hantavax^처리불가$). and the result showed their immunogenicities were slightly higher than those of inactivated suckling mouse vaccines. Therefore, this study shows the possibility of the development of Hantaan virus vaccine from a human cell culture.

• Journal of Microbiology
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• v.45 no.1
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• pp.29-33
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• 2007

Salmonella typhimurium, causing mouse typhoid, infects hosts such as macrophage cells, and proliferates in intracellular vacuoles causing infected cells to trigger numerous genes to respond against the infection. In this study, we tried to identify such genes in RAW264.7 cells by using the PCR screening method with degenerate primers. Fourteen genes were found to be differentially expressed after a 4 h infection in which the expression of 8 genes increased while expression of the others decreased. Most of the genes were involved in proinflammatory responses such as cytokines production and cell death. The mutation in msbB gene encoding the myristoyl transferase in lipid A of lipopolysaccharide (LPS) resulted in much lower toxicity to the inoculated animals. We compared the expression of the identified genes in wild-type and msbB-mutated S. typhimurium infections and found that Lyzs encoding lysozyme type M was differentially expressed. This gene is quite likely to be related to bacterial survival in the host cells.

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.37-42
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• 2017

Getah virus (GETV) infection causes sporadic outbreaks of mild febrile illness in horses and reproductive failure in pigs. In this study, we established a reverse transcription polymerase chain reaction (RT-PCR) method to detect GETV from suspected virus-infected samples. The reaction conditions were optimized and validated by using RNA extracted from GETV propagated in cell culture. A GETV-specific GED4 primer set was designed and used to amplify a 177 bp DNA fragment from a highly conserved region of the E1 glycoprotein gene in the GETV genome. RT-PCR performed with this primer set revealed high sensitivity and specificity. In the sensitivity test, the GED4 primer set detected GETV RNA at the level of $10^{2.0}\;TCID_{50}/mL$. In the specificity test, the GED4 primer set amplified only a single band of PCR product on the GETV RNA template, without non-specific amplification, and exhibited no cross-reactivity with other viral RNAs. These results suggest that this newly established RT-PCR method is useful for accurate identification of GETV infection in animals.

• Journal of Korean Critical Care Nursing
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• v.11 no.1
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• pp.101-109
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• 2018

Purpose : The purpose of this study was to identify the knowledge, perception and hand hygiene performance rate of hospital nurses and to identify any correlation between them. Method : Data were collected from 205 nurses working in a university hospital in Chungcheong-do. A self-report survey method was utilized. Participants completed the hand hygiene knowledge questionnaire. Results : The average knowledge of hand hygiene was 11.76 (out of 18 points), and the average perception of hand hygiene was 35.55 (out of 96). The hand hygiene performance rate was 85.62%. Knowledge of hand hygiene showed significant differences according to age (F = 75.821, p < .001), gender (t = 25.049, p < .001) and working period (F = 24.843, p < .001). The most important explanatory factor in hand hygiene performance was hand hygiene perception (${\beta}=.26$), followed by working period (${\beta}=.14$). These variables accounted for 10.0% of subjects' hand hygiene performance. Conclusion : The results of this study suggest that continuous and effective education is needed to strengthen knowledge and perception of the importance of hand hygiene practice for nurses to prevent healthcare-associated infections.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.3
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• pp.308-316
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• 2013

The purpose of this study is to investigate the production method of posterior bridges pontic ridge lap type which prevents the infection in bridge pontic base and is able to cleanse itself, in the process of producing final prothesis that maintains healthy mucous membrane of oral cavity and interproximal papilla, minimizing diastema, is aesthetic and has no effect on pronunciation. New technology is applied to make optimal pontic base which prevent inflammation and clean itself and its products were clinically evaluated in 10 places of dental clinics in busan and gyeongnam. The making of posterior 3 unit bridge pontic base, it was presented as the new technology of forming ridge lab type and to carry out clinical validation, existing conventional method and the new technology were compared. Pontic base made with the existing conventional method cause infection and other periodontal disease by 96% but the pontic base made with the new technology cause infection and other periodontal disease by 3%. Remains of food cause infection and other periodontal disease 100% by the existing conventional method and 91% by the new technology, showing a distinct difference. However, after a gargle, the new technology had low 13%. Additionally, the pontic base made with the existing conventional method showed 71% of chance, the new technology method showed 8% of chance in terms of self-cleansing.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.54-54
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• 2019

Apple (Malus domestica) is one of the most economically important fruits in Korea. But virus infection has decreased sustainable production of apple and caused the serious problems such as yield loss and poor fruit quality. Virus or viroid infection including Apple chlorotic leaf spot virus (ACLSV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), Apple mosaic virus (ApMV) and Apple scar skin viroid (ASSVd) has been also reported in Korea. In many cases, apple is infected with virus and viroid with no specific symptoms, the damage caused by the virus are unaware significantly. In our research, we tried to eliminate viruses in the rootstock for the disease-free seedlings of the apple dwarfing rootstock M.9 and M.26. The method of virus elimination was meristem culture, heat($37^{\circ}C$, 6weeks) treatment and chemistry($Ribavirin^{(R)}$) treatment. The analytical methods commonly used for the detection of virus is Enzyme-linked Immuno-Sorbent Assay(ELlSA) and Reverse Transcription-polymerase Chain Reaction(RT-PCR). RT-PCR method was more 30% sensitive than ELISA method. Efficiency of method eliminate virus appeared meristem method > heat treatment > chemistry treatment. The higher acquisition rate of disease-free seedlings is 30~40% on meristem treatment. In meristem treatment, the apple dwarfing rootstock M.9 gained infection ratio of ACLSV, ASPV and ASGV were 45%, 60% and 50% respectively. In the apple dwarfing rootstock M.26, infection ratio of ACLSV, ASPV and ASGV were 40%, 55%, 55%, respectively. Based on our results, it was found that most effective method of disease-free seedlings apple dwarfing rootstocks was by meristem treatment than heat method and chemistry treatment.

• The Plant Pathology Journal
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• v.15 no.4
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• pp.158-161
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• 1999

We determined threshold environmental factros to initiate infection of pepper plants by Botrytis cinerea, a fungal pathogen of pepper gray mold, in two greenhouse conditions. A new efficient spore-trapping method was developed to estimate population density of airborne conidia in the greenhouses, and spore release was measured using a Kerssies' selective medium. At a given day, spores were released greater during daytime (mostly from 7:30 am to 10:30 am and at 4:30 pm) than nighttime. Diurnal and nocturnal temperatures in the greenhouse-1 were about $25^{\circ}$ and $17^{\circ}$,and relative humidity was 100% for prolonged 24 h due to rain on December 17, 1997. Population density of air-borne conidia was 3.0$\times$103 conidia/ $0.5\textrm{m}^3$ after two days, and the initial infection occurred in ten days. During the same period of time in the greenhouse-2, diurnal temperature was about $25^{\circ}$ and nocturnal temperature was below $15^{\circ}$, and population density of air-borne conidia was 104 conidia/ $0.5\textrm{m}^3$. Under these conditions, the initial infection started in three days. This indicates that the early infection occurs under which diurnal temperature is approximately $25^{\circ}$, nocturnal temperature is maintained below $15^{\circ}$, and population density of air-borne conidia is 104 conidia/ $0.5\textrm{m}^3$ at saturated relative humidity condition.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.223-229
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• 1984

An attempt to confirm the associations of some selected risk factors of HBV infection and measure their risks, a cross-sectional study with 1,209 urban office workers was carried out. For the study, a simple questionnaire which contained several questions on personal experience and behaviors on several known selected risk factors of HBV infection was applied to each subject, and the Hepatitis B virus surface antigen and its antibody were checked by RPHA and PHA method, respectively. Risk factors chosen for this study were experience of blood transfusion and personal contact variables, such as frequencies of eating-out, drinking after office hours, going to tea room, sharing cigarettes, etc. The results obtained were as follows: 1. The proportion of HBsAg positive was 10.6%, and total HVB infected including the Anti-HBs positive cases without vaccination was 44.2%. Both were higher in male than in female. 2. Frequent personal contact through glasses and dishes in eating-outs and drinkings turned out not to be a significant risk factor of Hepatitis B surface antigenecity. 3. Frequent visits to tea room was a significant risk factor of HBV infection which combined HBsAg positive cases and Anti-HBs cases who had not received HBV vaccination. The odds ratio was 1.56 4. Blood transfusion was not a significant risk factor of both HBsAg positive and total HBV infection. In summary, indirect oral contacts through eating-outs and drinkings was not significant risk factor in Korea at least between adults. Blood transfusion is no more major source of HBV infection in Korea probably because the adquate screening test of HBsAg for the blood donors is being made.

• Journal of Korean society of Dental Hygiene
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• v.14 no.4
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• pp.463-470
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• 2014

Objectives : The purpose of this study was to investigate the association factors of infection control practice based on health belief model in the dental hygienists in dental clinics. Methods : A self-reported questionnaire was filled out by 278 dental hygienists in 160 dental clinics in Gwangju by a proportional stratified sampling method from September 13 to October 7, 2013. Data were analyzed by t-test, ANOVA, correlation analysis, and multiple regression analysis using SPSS version 12.0. Results : In multiple regression analysis, practice scores were significantly higher in aged dental hygienists and those who took infectious disease history from the patients before treatment. With regard to health belief model, perceived barrier was negatively associated with the practice(${\beta}$=-.16, p<.001), importance of infection control in hand hygiene(${\beta}$=.14, p=.026), and use of personal protective equipment(${\beta}$=.17, p=.043). The intention of action was positively associated with the practice(${\beta}$=.13, p=.002). Conclusions : This study will provide the basic evidence for the quality improvement of infection control and prevention. So the dental hygienists will be able to put into practice in infection control management.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1218-1223
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• 1999

The purposes of this study are to examine seroprevalence of Mycoplasma hyopneumoniae infection in pigs of different age groups, and retrospectively determine if nursery depopulation (ND) could influence the seroprevalence of M hyopneumoniae infection in nurseries. Sera of 4, 8, 12, 16, and 20 weeks old pigs from 7 farms were first selected from a serum bank to examine serologic profiles for M hyopneumoniae infections. Availability of representative sera in the serum bank was a major criterion for farm selection. The sera were tested for M hyopneumoniae antibodies by an enzyme linked immunosorbent assay (ELISA) using Tween-20 extracted antigen. Serum samples were also selected from 15 of 34 swine farms that previously participated in a ND study. In order to evaluate M hyopneumoniae infection following ND, ELISA was performed with sera of 8~10 weeks old nursery pigs collected prior to and after ND for up to 12 months from the 15 farms. Serological profiles showed positive ELISA titers for 2 of 7 farms at 8 weeks, 4 of 7 farms at 12 weeks, 6 of 7 farms at 16 weeks, 6 of 6 farms at 20 weeks of age. Prior to ND, 11 of the 15 farms had positive titers in sera of 8~10 weeks old pigs. Sera of 8~10 weeks old pigs collected from 7 of the 11 farms (63.6%) were ELISA antibody negative for up to 12 months following ND. In conclusion, seroconversion to M hyopneumoniae was detected commonly between 10~16 weeks of age, indicating the occurrence of natural infection during the nursery age. The ND appeared to be an effective method to prevent M hyopneumoniae infection within the nursery pig in some farms.