• Biomolecules & Therapeutics
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• v.6 no.1
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• pp.14-19
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• 1998

In the present study, we intended to investigate whether cationic polyamines including poly-L-Iysine (PLL) and poly-L-arginine (PLA) induce cytotoxicities to cultured hamster tracheal surface epithelial (HTSE) cells. Confluent HTSE cells were chased for 30 min in the presence of PLL or PLA of different molecular weights. Possible cytotoxicities of PLL or PLA were assessed by measuring both Lactate Dehy- drogenase (LDH) release during treatment and the number of floating cells after treatment and by checking the possible changes on the morphology of HTSE cells during treatment. The results were as follows: in the case of treatment of PLL or rLA of which molecular weight is about 78,000 and 92,000, respectively, (1) there was significant release of LDH during treatment, (2) the number of floating cells were significantly increased after treatment and (3) there were significant changes on the morphology of cultured HTSE cells. However, in the case of PLL or PLA of which molecular weight is under 10,000 (about 9,600 and 8,900, respectively), no significant signs of cytotoxicities mentioned above were detected. We found that cationic polyamines might be non-toxic under specific range of molecular weights and suggest that the cytotoxicity of cationic polyamine might depend on the molecular sizes of each cationic polyamine.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.390-397
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• 2013

Primary-cultured immune cells are widely used in research to elucidate the mechanism of inflammation including chemotaxis, production of reactive oxygen species, cytokine release and antigen presenting. Mice are one of the species of experimental animals commonly used for such studies. Immune cells can be isolated and cultured from various organs such as bone marrow, peritoneal cavity, lung, spleen. For elaborated experimental studies, immune cells should be elicited with inflammatory substances or proliferated in vitro with special media. This paper details methods of obtaining immune cells from various organs of mice and investigating immune mechanism using isolated immune cells. It contains standard protocols of isolating and culturing immune cells from bone marrow, peritoneal cavity and lymphoid organs. It also covers the methods of investigating immune mechanism such as ELISA, western blotting, confocal microscopy and ELISPOT assay. With the works in this study, we established the standardized isolation and analysis methods of primary-cultured immune cells.

• Journal of The Korean Association of Information Education
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• v.2 no.2
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• pp.189-200
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• 1998

Educational utilization of the Web has drawn much interest from educational institutions due to advantages such as arousing interest, self-motivated participation, and acquisition of up-to-the-minute information beyond time and spatial limitation. Researches have been focused on searching and retrieving information from the Web in many different ways. In this paper, we introduce Web-based project which emphasizes on an organized and unified way of using the Web, a higher level methodology than just gathering and searching information. The advantages of Web-based project can be considered as wide experiences of the subject, integrated curricular education, creativity development, cultivation of cooperative spirit, global education, etc. We address basic concepts of managing Web-based project and discuss applicable areas. Also, we propose a fundamental design structure of Web-based project.

• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.257-261
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• 2003

This experiment was carried out to investigate the effects of plant growth regulators on the organogenesis from the tissue culture of Arabidopsis thaliana stem, and the origin of the callus development. When the stem segments were cultured on medium with 2mg/L IAA or NAA, adventitious roots and trichomes were differentiated after 11 days of culture. Callus vigorously formed on medium with 2/L2,4 after 7 days of culture, but adventitious roots and trichomes were not differentiated from callus after 10 days of culture. This results suggesting that picloram is very effective auxin for the callus formation and organogenesis. Callus weakly formed on 0.05mg/L kinetin, and formed on combination of auxins(2mg/L) with 0.05mg/L kinetin. But the effect of combination of auxins and kinetin the callus formation was less than 2,4-D or picloram alone. A histological examination of callus formed on picloram showed that phloram showed that phloem parenchyma cells were divided and enlarged after 2 days of culture. Cortex parenchyma cells were divided and meristematic nodules were developed from these cells after 4 days of culture. Finally, callus formed on outside of cortex and epidermis by division of meristematic nodules after 7 days of culture.

• Biomolecules & Therapeutics
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• v.10 no.3
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• pp.156-164
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• 2002

In the present study, we tried to investigate whether polymerized basic amino acid e.g. poly-L-lysine (PLL) which has the degree of polymerization under 50mer significantly affects the physiological and stimulated mucin release from cultured hamster tracheal surface epithelial cells. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with $^3{H}$-glucosamine for 24 hr and chased for 30 min in the presence of either PLLs or adenosine triphosphate (ATP) and PLL to assess the effects on basic or ATP-stimulated $^3{H}$-mucin release. Possible cytotoxicities of PLLs were assessed by measuring lactate dehydrogenase (LDH) release from HTSE cel1s during treatment. The results were as follows: PLLs significantly inhibited basic mucin release from cultured HTSE cells in a dose-dependent manner from the range of 46mer to 14mer; PLL 46mer significantly inhibited the stimulated mucin release by ATP from cultured HTSE cells; there was no significant release of LDH from cultured HTSE cells during treatment. We conclude that PLLs inhibit both physiological and stimulated mucin release from airway epithelial cells without significant cytotoxicity and PLL lost its activity under the range of 14mer. This finding suggests that polymer of basic amino acid like PLL might function as a regulator for hypersecretion of mucus manifested in various respiratory diseases.

• The Korean Journal of Zoology
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• v.35 no.3
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• pp.295-307
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• 1992

In order to study the differentiation of the epithelial cells during the development of fetal rat lung tissue, histological changeB in organotypic culture and in vivo were examined. Light microscopy and scanning electron microscopy were used to analvre the histological change in rat lung from the 15th nary of gestation to the 111th nary after birth. In organotypic culture system, the pulmonary epithelial cell differentiation was studied by scanning electron microscopy. The results obtained from this study were as follows. 1. During deveiopment of lung, the glandular stage lasted from the Isth day to the lsth naut of gestation; the canalicular stage from the 17th nay to the 19th naut of gestation; the saccuiar stage from 20th nary to the birth. Alveolar stage was observed at the 3rd nary of postnatal rat lung. 2. In organotvpic culture of fetal rat lung cells organized alveolar-like structures resembling those of in uiuo state were observed on the gelatin matrix. In contrast with in vivo state, fetal lung cells formed group of type ll pneumocytes predominently along the contours of the matrix. These cells have large apical surface, short microvilli and secreted materials which may be sunactant. These results suggested that an orsanotypic culture retaining epithelial- -mesenchvmal relationships is appropriate culture model to study the pulmonary epithelial cell (especially type ll pneumocvte) differentation.

• Neonatal Medicine
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• v.18 no.2
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• pp.280-287
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• 2011

Purpose: The purpose of the present study was to determine the association of positive Ureaplasma urealyticum in gastric fluid with clinical features and outcomes in preterm infants. Methods: Gastric fluid from the preterm infants was first aspirated within 30 minutes and cultured within 24 hours after birth to check for U. urealyticum. Infants were divided into two groups on the basis of the presence/absence of U. urealyticum. Results: U. urealyticum in gastric fluid was identified in 17 of 91 (19%) preterm infants. Compared with the negative U. urealyticum group, there were significantly higher percentage of infants with gestational age ${\leq}$30 weeks (P=0.020), higher Apgar score at 1 minute and 5 minutes (P=0.017 and P=0.048, respectively), and higher rate of vaginal delivery (P=0.000) in the positive U. urealyticum group. Although the incidence rate of bronchopulmonary dysplasia between the two groups was not different, the frequency of bronchopulmonary dysplasia without previous respiratory distress syndrome was significantly higher in the positive group (11%) than that in the negative group (1%) (P=0.030). Conclusion: The detection of U. urealyticum in gastric fluid is more frequent in infants with gestational age ${\leq}$30 weeks. It can be helpful to predict the development of bronchopulmonary dysplasia without previous respiratory distress syndrome in preterm infants.

• Tuberculosis and Respiratory Diseases
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• v.40 no.1
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• pp.29-34
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• 1993

Background: The development of the flexible fiberoptic broncoscope by Ikeda was an important technologic advance in the diagnosis and management of patients with pulmonary disease. But, cross contamination related to fiberoptic bronchoscope was reported in cases involving tubercle bacilli, MOTT and other agents. Therefore, cleaning and disinfecting of fiberoptic bronchoscope requires careful attention. Methods: From September 1991 to May 1992, medical records of all patients with positive culture for MOTT in bronchial washing specimens were reviewed. Also to evaluate bactericidal effect of 2% glutaraldehyde, culture was performed after inoculum of MOTT, Serratia marsescens and Pseudomonas aeruginosa to the disinfectant solution. Results: In 2% alkaline glutaraldehyde, MOTT was not survived only after 30 minute exposure, but P. aeruginosa and S. marsescens were rapidly inactivated with no survivors after exposure to 2% glutaraldehyde. Since vigorous mechanical cleansing and more than 30 minute of contact time within washing machine, no more outbreak was observed. Conclusions: It is also very important that bronchoscopes must be meticulously cleaned after each procedure and more than 30 minute exposure would be required for eradication of MOTT with 2% glutaraldehyde. However even the most strictly applied infection control measures cannot exclude contamination completly and clinicians have to stay alert to this possibility. Prompt detection of pseudoepidemics is possible if abrupt increase in isolation rates, especially if they involve unusual or generally nonpathogenic organisms, are readily recognized.

• Information Systems Review
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• v.14 no.2
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• pp.117-140
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• 2012

It is hard, but important to evaluate and select a new service model for the public sector, accompanying unexpectable risk. The purpose of this study is to build and develop the evaluation framework of public projects and to present a project evaluation system which is more rational and methodical. The evaluation framework has been developed by calculating the evaluation criteria and weights resulted from an interview with an expert group and Analytic Hierarchy Process(AHP). Moreover, market-oriented characteristics, technology-oriented characteristics, service development capabilities and policy-oriented characteristics were predominantly chosen as the evaluation items. The re-evaluation of the app development support programs was conducted to check the feasibility as an evaluation system influencing the performance of firms. The result of an evaluation system proposed by this study showed better evaluation performance than previous ones, better predicting the actual business performance. Currently, though the policies of the public sectors and support programs focus on the outcome and performance management, the result of this study shows the importance of project selections. Also, implications of the study are discussed.

• Pediatric Infection and Vaccine
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• v.21 no.2
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• pp.114-120
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• 2014

Purpose: The objective of this study was to assess and investigate the epidemiology of pertussis in infants under 6 months of age. Methods: A prospective study was conducted between October 1, 2011 and April 30, 2013 in CHA Bundang Medical Center, Seongnam, South Korea. Polymerase chain reaction (PCR) or culture was used to detect Bordetella pertussis in nasopharyngeal aspirates from case patients who were hospitalized for acute lower respiratory tract infection (LRTI). In addition, multiplex real-time PCR assays were also performed to detect 6 etiologic viruses, including adenovirus, human metapeumo-virus, influenza virus, parainfluenza virus, respiratory syncytial virus and rhinovirus. Results: Of the 79 enrolled case patients, whose median age was 2 months of age, the most common diagnoses uncovered in this study were acute bronchiolitis (60%) and pneumonia (28%). B. pertussis infection was found in 13 cases (16%), in which 7 (53%) was coinfected with respiratory syncytial virus and 1 (7%) with influenza A virus. Of the 13 patients with B. pertussis infection, 6 (46%) were not vaccinated with the diphtheria, tetanus toxoid, and acellular pertussis vaccine, while 6 (46%) received 1 dose, and 1 (8%) received 2 doses. Conclusion: B. pertussis infection was present in 16% of under 6 month-old infants, who were hospitalized for acute LRTI. Therefore, a nationwide epidemiological surveillance of pertussis, including institutions that cater to infants under 6 months of age is necessary and needed.