• Korean Journal of Plant Tissue Culture
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• v.24 no.1
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• pp.1-35
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• 1997

Fertilized egg, by successive cell divisions, differentiates into different tissues and organs with various structures and functions. Different cells and tissues contain different proteins, products of selective gene expression. Not all the genes in any genomes are equally active, temporal and spatial gene expression being the general rule. Present paper attempts to review the tanscriptional mechanisms or the initiations of transcription from several angles. In some of the organisms the genes in the process of transcription or the genes in the inactive state can be seen under the light microscope. Some bands of Drosophila polytene chromosomes may exhibit a swollen or puff appearance under certain conditions. A puff, unfolded or decondensed form of chromomere, represents sets of intense transcriptional activity or RNA synthesis. The heterochromatic X chromosome whose genes remain inactive in the female mammals can be visualized as a dark staining structure called Barr body, Configuration of chromatin differs between transcribed and nontranscribed chromatin. Modification to the chromatin facilitates RNA synthesis. The movement of large polymerase molecule along the DNA would probably be facilitated if some modifications of the chromatin configuration is effected. Methylation of cytosines in CG sequences is associated with inactive genes. Methylation can play a role in determination of mammalian cells during embryogenesis. Demethylation is necessary for the gene to be expressed during development A histone modification that is also known to be correlated with transcriptional capacity of chromatin is acetylation of the lysine residues of the core histones. Chromatin containing a high level of histone acetylation is very sensitive to DNase 1. For the transcription to occur TBP must first bind to the TATA box. Another TF, TF IIB, then binds to the promoter-TBP complex, facilitating the access of RNA polymerase to the transcription initiation site. As recently as eight years ago researchers assumed that histones were irrelevant to the regulation of gene expression. Histones combine with the DNA to form nucleosome of the chromatin. Histones are vital participant in gene regulation. Histone and basal factors compete for access to TATA box. When DNA is exposed to basal factors before histones are introduced, the basal factors assemble on TATA boxes preventing the access of histones, allowing transcription to occur, for transcription to begin, activator protein at the upstream activation sequence or enhancer must interact with the tail of histone H4 at TATA box and cause the histone role particle to dissociate from the TATA box leading to partial breakup of the histone core particle and allowing the basal factors to bind to the TATA box. New concept of genomic flux in contrast to the old concept of static genome has been developed based on the powerful new molecular techniques. Genomic changes such as repetitive DNAs and transposable elements, it is assumed but not yet proved, may affect some of the developmental patterns that characterize particular cells, tissues, organs, and organisms. In the last decade or so remarkable achievement have been made in the researches of the structures and functions of TFs and the specific target sequences located in promoters or enhancers where these TFs bind. TFs have independent domains that bind DNA and that activate transcription. DNA binding domain of TFs serves to bring the protein into the right location. There are many types of DNA binding domains. Common types of motifs can be found that are responsible for binding to DNA. The motifs are usually quite short and comprise only a small part of the protein structure. Steroid receptors have domains for hormone binding, DNA binding, and activating transcription. The zinc finger motif comprises a DNA binding domain. Leucine zipper consist of a stretch of amino acids with a leucine residue in every seventh position Two proteins form a dimer because they interact by means of leucine zippers on similar α-helical domain. This positions their DNA binding basic domains for interaction with the two halves of a DNA sequence with dyad symmetry of TGACTCA, ACTGAGT.

• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1147-1152
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• 2009

Purpose:To characterize the pathogens and their antibiotic susceptibilities in more than 24-month-old children with urinary tract infection (UTI) and to study the Escherichia coli antimicrobial susceptibility trend. Methods:We retrospectively reviewed the record of more than 24-month-old children with UTI between January 2003 and December 2008. Positive results for 1 bacterial species with a colony count of ${\geq}10^5CFU/mL$ was considered statistically significant. We analyzed uropathogens and their antibiotic susceptibilities. To investigate E. coli antibiotic susceptibility trend, we compared 2 study periods (group A: 2003-2005 versus group B: 2006-2008) using the chi-square test for trend. Results:In all, 63 bacterial isolates were identified in children with febrile UTI. The most common pathogen was E. coli (77.8%). There was no difference in the resistance patterns of uropathogens during the 2 study periods (P>0.05). Antibiotic susceptibility of the E. coli isolates to aztreonam, cefotetan, cefotaxime, ceftriaxone, cefepime, amikacin, and imipenem was >90% to trimethoprim/sulfamethoxazol, 49% and to ampicillin and ampicillin/sulbactam, 20-25%. Over the 2 study period, the E. coli susceptibilities to most antibiotics did not change: the susceptibility to cefuroxime increased from 74.1% to 95.5% (P=0.046) and that to ciprofloxacin increased from 59.3% to 86.4% (P=0.039). Conclusion:Empirical treatment with trimethoprim/sulfamethoxazole, ampicillin, and ampicillin/sulbactam alone appeared to be insufficient in childhood UTI because of the high resistance of E. coli and other gram-negative uropathogens. Antibiotics for empirical therapy should be selected based on the sensitivity and resistance pattern of uropathogens found in a particular region.

• Korean Security Journal
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• no.22
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• pp.37-64
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• 2010

Since the September 11, 2001, the motives and objectives of terrorism that have been targeted at hard targets such as key national facilities have now shifted towards soft targets such as subways, department stores, and tourist hotels; the attacks on these soft targets are steadily increasing. Simultaneous, unconventional, and indiscriminate terrorist attacks on civilians has also increased. In November, 2010, nearly forty states of the G20 and B20 (Business 20) will join in international summits to be hosted in Seoul. This coming July, an additional 350 troops will be deployed to Afghanistan for the sustainment of public security. Such events are sensitive topics, and there is the possibility of terrorist movement. Korea has successfully hosted various international events such as the APEC and ASEM Summits, and the 2002 Korea-Japan World Cup. The experiences from these events must be applied to ensure the safety of public facilities against the dangers of terrorism. First, counter-terrorism center must be established for the long-term, above the General Officer level to ensure the safety and efficiency of multilateral, international summits, as well as promoting policies and legislation aimed at preventing terrorism. Second, a terrorist threat management system must be secured and safety measures must be emphasized. Third, a fundamental structure must be established for the prevention of terrorism on public facilities, as well as legal and government action against the new threat of IED. Fourth, the police and fire fighting networks' must have a firm rapid response posture on the scene of an attack. Fifth, the state of mentality on the recognition of terrorist threats must be changed and restructured by promoting to and educating the population. Sixth, prevention measures must be established via research and academia. Seventh, for the guarantee of security in public facilities, safety management should employ cutting edge technology such as the 3D SICS and further develop and apply such technology. All methods and resources must be fully utilized for the establishment and strengthening terrorism prevention measures.

• Journal of Korean Home Economics Education Association
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• v.21 no.2
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• pp.83-107
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• 2009

The purpose in this study was to provide a basic resource for enhancing teachers' professional competence by examining how the Home Economics(HE) teachers had formed, developed, and introspected the pedagogical content knowledge in the HE classes of secondary schools. Data were collected through in-depth interviews with six HE teachers working at secondary schools. NVivo program, a kind of CAQDAS was used to analyze the data inductively. This study revealed that the HE teachers reflectively introspected the pedagogical content knowledge in Home Economics Education(H-PCK) as follows: First, as for knowledge of perspective on Home Economics Education(HEE), the research participants encouraged students to solve practical problems regarding the objective of HEE. They tried to foster the students' critical thinking ability related to the daily life. They made eager efforts to achieve the mission of HEE as a practical science. Second, as for knowledge of HE curriculum, the research participants mentioned that there was lack of systematic approach concerned with curriculum development. While reorganizing, they always paid attention to its relation to the students' daily lives, to the relationship between the curriculum contents and the social context. Third, as for knowledge of teaching strategies on practical problem-based instruction, the research participants developed the practical problem-based instruction skills. They mentioned students' difficulties in relating the practical problem-based instruction, too. Fourth, regarding knowledge of context, as teachers mostly prepared for progressed instruction alone without communicating with colleagues in the same school, they yearned for and also formed networks with other HE teachers in order to overcome their limitations.

• Pediatric Infection and Vaccine
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• v.17 no.2
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• pp.83-90
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• 2010

Purpose : Although the incidence of polymicrobial bloodstream infection (PBSI) has increased, only a few studies have so far focused on children. Therefore, in an effort to prevent more serious situations in pediatric patients, we analyzed the clinical features, organisms, and laboratory results of PBSI. Methods : We performed a retrospective review of the case records of 97 patients with polymicrobial bloodstream infection in the Severance hospital, from 2001 to 2008. Using t-test and chi-square test, we analyzed the underlying medical conditions, clinical characteristics, organisms, and laboratory results of those patients. Results : Annual incidence of polymicrobial bloodstream infection increased from 1.4 % in 2001 to 10.9% in 2008 in pediatric patients. Immunocompromised hemato-oncological malignancy was found in 31 (31.9%) patients, and was the most common underlying medical condition; cardiovascular disease was found in 15 patients (15.4%), neurologic disease in 10 patients (10.3%), and so on. Gram positive organisms were recovered in 143 cases and gram negative organisms were recovered in 101 cases of PBSI. Staphylococcus epidermidis was the most common organism. Factors affecting mortality included underlying medical disease, immune status, nosocomial infection, and central catheter-related infection, for which the rate of mortality showed a greater increase (P<0.05). Conclusion : Due to the close connection between PBSI and fatal conditions or high mortality, it requires more aggressive management. Compared with previous studies, we discovered that immunocompromised hemato-oncological malignancy was the most common underlying medical condition and that frequency of gram-positive bacteria and fungus isolated has increased.

• Pediatric Infection and Vaccine
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• v.17 no.2
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• pp.122-129
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• 2010

Purpose : Enteroviral infection is a common viral illness in children. We undertook this study in attempt to comprehend the epidemiologic and clinical features of enteroviral infections, particularly EV71 in children. Methods : We enrolled 63 children with enteroviral infection at Severance Children's Hospital in Seoul between May and August 2009. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed from stool or cerebrospinal fluid samples, which were then tested for enteroviral infection. Viral isolation and serotype identification also were performed by RT-PCR. Results : A total of 63 patients with clinical diagnosis of enteroviral infections were enrolled; of those, 38 (60%) were positive for enterovirus. The mean age of the patients was 2 years and 7 months and the sex ratio of male to female was 0.9 :1. Their clincal manifestations included aseptic meningitis (21 cases, 55%), HFMD (16 cases, 42%), herpangina (5 cases, 13%), neonatal fever (2 cases, 5%), encephalitis (1 case, 3%), and myocarditis (1 case, 3%). Serotypes of isolated enteroviruses were EV71 (8 cases, 21%), coxsackievirus B1 (8 cases, 21%), coxsackievirus A16 (2 cases, 6%), coxsakievirus A2 (1 case, 3%), coxsakievirus A5 (1 case, 3%), and echovirus 9 (1 case, 3%). Clinical symptoms of EV71 infection included HFMD (5 cases, 63%), aseptic meningitis (3 cases, 38%), encephalitis (1 case, 13%), and myocarditis (1 case, 13%). A positive rate of C-reactive protein in EV71 was higher than those in other enterviral infections. However, there was no statistically significant difference in other laboratory findings. Conclusion : We reported on identified enteroviruses, including EV71, during a period of 3 months in the summer of 2009. In this study, EV71 infection frequently occurred in male and clinical manifestation caused by EV71 was a more severe disease than that due to other enterviral infections. There is a need for continuous surveillance of enteroviral infection and its clinical manifestations for diagnosis and treatment of enteroviral infection.

• Pediatric Infection and Vaccine
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• v.20 no.3
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• pp.161-167
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• 2013

Purpose: This study was performed to describe the clinical manifestations of hospitalized children due to varicella-zoster virus (VZV) infection Methods: This study included 40 children who were hospitalized for varicella or herpes zoster at Seoul National University Children's Hospital, 2009-2012. Diagnosis of VZV infection was confirmed by VZV PCR or culture from vesicular fluid. Medical records were reviewed to collect clinical features and outcome, antiviral treatment, history of varicella vaccination, and underlying diseases. Results: Sixteen patients with varicella and 24 patients with herpes zoster were included. Their median age was 10.5 years (16 days-19 years). Thirty-five (87.5%) patients had underlying diseases. Among 24 patients with herpes zoster, 11 patients had previous history of varicella and 1 had herpes zoster. Twenty patients (50%) had a history of varicella vaccination, and 19 immunocompromised patients had VZV infection despite of vaccination. Most (95%) patients were treated by intravenous or oral acyclovir, and no treatment failure of intravenous acyclovir was found. The median duration of fever was 4.4 days (1-10 days), and that of antiviral treatment was 12 days (7-23 days) in immunocompromised patients. Immunocompromised patients received longer duration of antiviral treatment than imunocompetent patients (P=0.014). Eleven (27.5 %) immunocompromised patients had postherpetic neuralgia, 2 (5%) had proven co-infection by Streptococcus pyogenes and Klebsiella oxytoca, and 1 (2.5%) complicated with pneumonia. Conclusion: Immunocompromised children require longer duration of treatment and are at risk of severe complication associated with VZV infection. Early initiation of antiviral therapy and close monitoring are necessary for those in immunocompromised conditions.

• The Journal of the Petrological Society of Korea
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• v.2 no.2
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• pp.74-94
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• 1993

Metabasites and metapelites in the Mungyong area were intruded by Cretaceous granites with radius of 4-8 km. As the distance from granite body increases, the mineral assemblage of metabasite changes from amphibole + plagioclase through amphibole + plagioclase + epidote to amphibole + plagioclase + epidote + chlorite. The compositional variations of amphibole and plagioclase according to the change of metamorphic grade and bulk rock compositions are very complex. Towards the Mungyong Cretaceous granite body, the mineral assemblage of metapelite changes from chlorite+ muscovite(ch1orite zone) through biotite + chlorite + muscovite(biotite zone) to andalusite+biotite + muscovite${\pm}$chlorite or cordierite+ biotite+ muscovite${\pm}$chlorite(cordierite zone). The estimated metamorphic conditions of cordierite zone are 480~$580^{\circ}C$ 1.5-3.3 kb. The theoretical study on the thermal metamorphism caused by the Cretaceous granite with radius longer than 4 km in the Mungyong area suggests the followings: The degree of metamorphism is mainly determined not by the size of granite body but by the temperature of granite intrusion; The country rocks within 2 km from Cretaceous granite have undergone metamorphism with temperature higher than $500^{\circ}C$, which is consistent with the petrological study in the Mungyong area. Mungyong Cretaceous granite caused a low P/T thermal metamorphism to the country rocks; the amphibolite facies metamorphism to the country rocks within 1-2 km from the granite body and the epidote-amphibolite and greenschist facies metamorphism to the country rocks within 2-5 km.

• Pediatric Infection and Vaccine
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• v.17 no.1
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• pp.36-48
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• 2010

Purpose : In children on anticancer chemotherapy, bloodstream infections (BSIs) are a major cause of morbidity and mortality. We investigated febrile episodes and bloodstream infections in pediatric cancer patients to guide proper selection of empiric antibiotics for febrile pediatric hemato-oncologic patients. Methods : All febrile episodes treated in the division of hematology-oncology, the department of pediatrics, Hanyang University Hospital, between July 2005 and June 2008 were reviewed. Episodes with and without bloodstream infections were compared. Results : Forty cases (18.9%, 25 patients) of BSI occurred in 212 febrile episodes (63 patients). Thirty-seven cases (23.6%, 22 patients) of BSI occurred in 157 febrile episodes with neutropenia (54 patients). Microorganisms identified in BSI corresponded to 23 gram-positive bacteria (51.2%), 20 gram-negative bacteria (44.5%), and 2 fungi (4.4%). Rates of BSI between those who had received umbilical cord blood transplantation and those who had received transplantation from other source were significantly different (55.0% vs. 7.7%, P =0.001). No differences in mortality rate were observed among organisms in BSI patients. For febrile episodes the rate of BSI was higher among those with Chemoport than those with Hickman catheter (P =0.029) and gram-positive pathogens were more likely to be associated with Chemoport (P =0.001). Conclusion : The study showed the rate of BSI, distribution of pathogens with regard to neutropenia, transplantation, central venous catheters, and antimicrobial susceptibility of pathogens in order to help guide in the choice of optimal empiric antibiotics in pediatric febrile neutropenic hemato-oncologic patients.

• Pediatric Infection and Vaccine
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• v.15 no.1
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• pp.45-51
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• 2008

Purpose : Better understanding of the epidemiology of Streptococcus pneumoniae affects preventive and therapeutic strategies for children with otitis media. This study was undertaken to examine the prevalence of pneumococcal serotypes causing otitis media in children. Methods : Pneumococcal isolates obtained from the ear discharge of children with otitis media between January 2001 and December 2006 were characterized by serotyping and antibiotic susceptibility testing. Results : There were 54 pneumococcal isolates from 54 children with otitis media. The median age of patients was 13 months, and the proportion of children <5 years old was 81%. The predominant serotypes, in order of decreasing frequency, were 19A (44%), 19F(28%), 6B (7%), 6A (4%), 9V (4%), and 1 (4%); 23 isolates (43%) belonged to types included in the heptavalent pneumococcal conjugate vaccine (PCV7). The proportion of serotype 19A and 19F accounted for 72% of overall pneumococcal isolates, which accounted for 84% of pneumococcal isolates from otorrhea of children <5 years old (vs 20% in children ${\geq}5$ years old, P<0.001). All serotypes isolated from 3 vaccinees of PCV7 were 19A. There was no significant diminution in otitis media caused by pneumococcal vaccine serotypes after the introduction of PCV7. The frequency of nonsusceptibility to penicillin, erythromycin, and trimethoprim-sulfamethoxazole was higher in serotype 19A than in other non-vaccine serotypes, respectively. The frequency of multiple drug resistance was 96% in serotype 19A, compared with 29% in other non-vaccine serotypes (P=0.001). Conclusion : 19A was the most common pneumococcal serotype causing otitis media and represented a large proportion of strains with multiple drug resistance in children younger than 5 years of age.