• The Korean Journal of Pesticide Science
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• v.11 no.4
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• pp.246-253
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• 2007

The reproduction toxicity of several pesticides on two Korean water flea was investigated to develop a new standard species used for ecological risk assessment of pesticide. Moina macrocopa and Daphnia sp. were exposed to 4 different types of pesticides over 10 and 21 days, respectively. No-ohserved effect concentration (NOEC) for synthetic pyrethroid, fenpropathrin on Moina macrocopa and Daphnia sp. were 0.17 and $0.06\;{\mu}g\;L^{-1}$, respectively. Diazinon, carbofuran and myclobutanil were in the order of their reproduction toxicity to cladocerans tested. There were large differences between Moina macrocopa and Daphnia sp. in their susceptibility to fenpropathrin, diazinon and carbofuran except myclobutanil. Daphnia sp. is more sensitive than M. macrocopa to pesticides tested. Therefore Daphnia sp. may be a good surrogate species to assess the reproduction effect of pesticides on aquatic invertebrates. M. macrocopa also be a good surrogate species because it is one of the most abundant cladocera in agricultural environment, especially rice paddy in Korea. In addition to it's ecological importance of wide spread distribution, it has also economical importance to make possible to shorten period for reproduction test using M. macrocopa due to it's short life cycle.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1181-1186
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• 2014

Sialyltransferase gene expression is altered in several cancers, including examples in the cervix. Transcriptional regulation of the responsible genes depends on different promoters. We aimed to determine the association of single-nucleotide polymorphisms in the B3 promoter of the ST3GAL4 gene and the P1 promoter of the ST6GAL1 gene with cervical premalignant lesions or cervical cancer. A blood sample and/or cervical scrapes were obtained from 104 women with normal cytology, 154 with premalignant lesions and 100 with cervical cancer. We also included 119 blood samples of random donors. The polymorphisms were identified by sequencing from PCR products. For the B3 promoter, a fragment of 506 bp (from nucleotide -408 to +98) was analyzed, and for the P1 promoter a 490 bp (-326 to +164) fragment. The polymorphism analysis showed that at SNP rs10893506, genotypes CC and CT of the ST3GAL4 B3 promoter were associated with the presence of premalignant lesions (OR=2.89; 95%CI 1.72-4.85) and cervical cancer (OR=2.23; 95%CI 1.27-3.91). We detected only one allele of each polymorphism in the ST6GAL1 P1 promoter. We did not detect any genetic variability in the P1 promoter region in our study population. Our results suggest that the rs10893506 polymorphism -22C/T may increase susceptibility to premalignant and malignant lesions of the cervix.

• Korean Journal of Microbiology
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• v.43 no.4
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• pp.256-263
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• 2007

We performed the biochemical characteristics, molecular epidemiologocal analysis, and drug susceptibility test on V. vulnificus isolated from environmental sources in Incheon. For this study, 233 strains were isolated from seawater, sediment, shellfish. V. vulnificus isolates were divided into 15 biochemical groups, which were positive for ONPG and Amygdalin test. Among the 209 strains, 206 (98.6%) strains and 110 (52.6%) strains revealed positive for vvhA and viuB gene, and the viuB gene detection rates of V. vulnificus from seawater, shellfish and sediment were 48%, 48.5% and 61.6%, respectively. From disc diffusion test on 175 isolates, most of strains were sensitive to Imipenem (100.0%), Sulfamethoxazole/trimethoprim (98.9%), Tetracycline, Ciprofloxacin (98.3%), Ampicillin/sulbactam (97.1%), Ohloramphenicol (96.6%), Cefepime (94.9%) and Ceftriaxone (94.8%), multi-drug resistance rates was 31.5% of seawater, 34.4% of sediment and 29.2% of shellfish. PFGE was performed on 233 V. vulnificus isolates with the objective of investigating the extent of genetic diversity of these isolates in our region. We could find that at least 126 different PFGE patterns were generated according by 90% of similarity and 13 clusters by 58% of similarity. The major cluster was type I (44.6%) during the most of the year, and type J was frequent pattern in June and October. There were 9 distinct PFGE types in July, 8 types in August, 7 types in June, 6 types in September, 5 types in October 3 types in May and 1 type in March.

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.171-179
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• 2006

Background : Despite the emerging danger of MDR-TB to human beings, there have only been a limited number of drugs developed to treat MDR-TB since 1970. This study investigated the cross-resistance rate between rifampicin (RFP) and rifabutin (RBU) in order to determine the efficacy of rifabutin in treating MDR-TB. In addition, the results of rifabutin were correlated with the rpoB mutations, which are believed to be markers for MDR-TB and RFP resistance. Methods : The MICs of RBU were tested against 126 clinical isolates of MDR-TB submitted to the clinical laboratory of National Masan TB Hospital in 2004. Five different concentrations ($10-160{\mu}g/ml$) were used for the MICs. The detection of the rpoB mutations was performed using a RFP resistance detection kit with a line probe assay(LiPA), which contains the oligonucleotide probes for 5 wide type and 3 specific mutations (513CCA, 516GTC, and 531TTG) The rpoB mutation was determined by direct sequencing. Results : The rate of cross-resistance between RFP and RBU was 70.5%(74/105) at $20{\mu}g/ml$ RBU(ed note: How much RFP?) Most mutations (86.3%) occurred in the 524~534 codons. The His526Gln, His526Leu, Leu533Pro, Gln513Glu, and Leu511Pro mutations(Ed note: Is this correct?) were associated with the susceptibilty to RBU. Conclusion : Based on the cross-resistance rate between RFP and RBU, RBU may be used effectively in some MDR-TB patients. Therefore, a conventional drug susceptibility test for RBU and a determination of the critical concentration are needed. However, rpoB gene mutation test may be have limited clinical applications in detecting RBU resistance.

• 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.

• Clinical and Experimental Pediatrics
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• v.46 no.1
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• pp.24-32
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• 2003

Purpose : Nosocomial infection with Staphylococcus aureus, especially methicillin resistant S. aureus, has become a serious concern in the neonatal intensive care unit. The aim of this study is to investigate the virulence factors, and the relationship between the antibiotic resistance and the associated genes of Staphylococcus aureus isolated from nasal cavity of neonates. Methods : Fifty one isolates of S. aureus were obtained from nasal swab taken in 28 neonates in the NICU and nursery of Pusan National University Hospital between February and May, 2001. They were tested in regard to antibiotic susceptibility, coagulase test and typing, plasmid DNA profile, as well as reactivity to enterotoxin A-E(sea, seb, sec, sed, see) genes and toxic shock syndrome toxin-1(tst) gene by polymerase chain reaction(PCR). Associated genes such as mecA, mecR1, mecI, and femA were also determined by PCR. The origin of MRSA strains was assessed using DNA fingerprinting by arbitrarily-primed polymerase chain reaction(AP-PCR). Results : Twenty three(45.1%) and six(11.8%) isolates were resistant to oxacillin and vancomycin respectively. Multidrug resistance to three or more of the antibiotics tested was observed in 51.0% of the isolates. Forty two isolates were coagulase positive and twenty two isolates had mecA gene. Sixteen isolates had both mecA and femA genes and had type I-III plasmids. 64.7% of isolates carried sec gene, and 80.4% carried tst gene. DNA fingerprinting by AP-PCR for 12 MRSA strains showed 10 distinct patterns, suggesting different origins. Conclusion : We confirmed that the prevalence of nasal carriage of S. aureus and the incidence of antimicrobial-resistant S. aureus, especially vancomycin resistance, is very high in neonates who were admitted in NICU and nursery. It is possible that these pathogens are responsible for serious nosocomial infections in neonates. The need for improved surveillance and continuous control of pathogens is emphasized.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.240-245
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• 2012

Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium that causes serious infection, particularly in immunocompromised patients. Also, P. aeruginosa possessing carbapenem-resistant metallo-${\beta}$-lactamases (MBL) has been reported with increasing frequency in Korea. We therefore analyzed the level of multidrug-resistant clinical P. aeruginosa isolated from a secondary hospital in Korea in 2010. A total of 92 isolates of P. aeruginosa were collected from Sahmyook Medical Center in 2010. Susceptibility to antimicrobial agents was determined by analysis of the minimum inhibitory concentration test; the inhibitor-potentiated disk diffusion (IPD) test was performed for MBL detection. RAPD-PCR was used for genotyping to rapidly characterize P. aeruginosa strains isolated from clinical patients. The percentages of non-susceptible isolates were as follows: 40.2% to ceftazidime, 58.7% to meropenem, 56.5% to gentamicin, 46.7% to tobramycin, 62.0% to ciprofloxacin and 97.8% to chloramphenicol. The 29 multidrug-resistant strains were screened by the IPD test: of the 21 PCR-positive isolates, 19 were IPM-1 producers and 2 were VIM-2 producers. Among the 19 IMP-1-producing P. aeruginosa isolates, 16 isolates showed similar patterns, and three different banding patterns were observed. The proportion of IMP-1-producing multidrug-resistant P. aeruginosa from clinical isolates steadily increased in this secondary hospital in Korea in 2010. This study provides information about the antimicrobial-resistant patterns and genotype of multidrug-resistant P. aeruginosa isolated from clinical isolates in Korea, 2010.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.4
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• pp.280-290
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• 2007

Purpose: Gender differences in personality are considered to have biological bases. In an attempt to understand the gender differences of personality on neurobiological bases, we conducted correlation analyses between regional brain glucose metabolism and temperament factors of personality in males and females. Materials and Methods: Thirty-six healthy right-handed volunteers (18 males, 33.8$\pm$17.6 y; 18 females, 36.2$\pm$20.4 y) underwent FDG PET at resting state. Three temperament factors of personality (novelty seeking (NS), harm avoidance (HA), reward dependence (RD)) were assessed using Cloninger's 240-item Temperament and Character Inventory (TCD within 10 days of FOG PET scan. Correlation between regional glucose metabolism and each temperament factor was tested using SPM2. Results: In males, a significant negative correlation between NS score and glucose metabolism was observed in the bilateral superior temporal gyri, the hippocampus and the insula, while it was found in the bilateral middle frontal gyri, the right superior temporal gyrus and the left cingulate cortex and the putamen in females. A positive HA correlation was found in the right midbrain and the left cingulate gyrus in males, but in the bilateral basal ganglia in females. A negative RD correlation was observed in the right middle frontal and the left middle temporal gyri in males, while the correlation was found in the bilateral middle frontal gyri and the right basal ganglia and the superior temporal gyrus in females. Conclusion: These data demonstrate different cortical and subcortical metabolic correlates of temperament factors of personality between males and females. These results may help understand biological substrate of gender differences in personality and susceptibility to neuropsychiatric illnesses.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.295-301
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• 2004

Recently, the rapid increase and global spread of extended-spectrum $\beta-lactamase$ producing clinical isolates has become a serious problem. The incidence of extended-spectrum $\beta-lactamase$ producing clinical isolates of Escherichia coli in Korea and susceptibility to antimicrobial agents were investigated. Total 233 isolates of E. coli were obtained from urine from hospitalized patients in Guro hospital, Korea University in 2001. One hun­dred and eighty four isolates $(78.9\%)$ were resistant to ampicillin, 80 isolates $(34.3\%)$ were resistant to ceph­alothin, 93 isolates $(39.9\%)$ were resistant to gentamicin, and 64 isolates $(27.5\%)$ were resistant to norfloxacin. Among 233 isolates, 17 isolates $(7.3\%)$ were positive as determined by the double disk synergy test. When min­imal inhibitory concentrations were assayed with additional 6 antimicrobial agents, 13 isolates $(76.5\%)$ were multi-drug resistant to at least four different class antimicrobial agents. Extended-spectrum $\beta-lactamase$ were characterized with isoelectric focusing gel electrophoresis and DNA sequencing. They were TEM-1 in 5 iso­lates, TEM-15 in 1 isolate, TEM-20 in 1 isolate, TEM-52 in 4 isolates, TEM-1 and AmpC in 2 isolates, TEM-1 and OXA-30 in 1 isolate, TEM-1 and OXA-33 in 1 isolate, TEM-1, CTX-M-3, and AmpC in 1 isolate, but SHV was not detected. Antimicrobial resistance genes were transferred to animal isolate of E. coli (CCARM No. 1203) by the filter mating method. Extended spectrum $\beta-lactamase$ producers studied in the current study have low correlation to each other as determined by random amplified polymorphic DNA and pulsed field gel elec­trophoresis. This is a contradictory result from the general hypothesis that extended-spectrum $\beta-lactamase$ pro­ducers in one hospital is a result from a clonal spread.

• Sleep Medicine and Psychophysiology
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• v.20 no.2
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• pp.63-68
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• 2013

Objectives: Several evidence has been suggested that the circadian gene variants contribute to the pathogenesis of seasonal affective disorder. In this study, we aimed to investigate the polymorphism in RORA (Retinoid-related orphan receptor A) gene in relation to seasonal variations among healthy young adults in Seoul, Korea. Methods: A total of 507 young healthy adult subjects were recruited by advertisement. Seasonal variations were assessed by the Seasonality Pattern Assessment Questionnaire (SPAQ). Single-nucleotide polymorphism in the RORA rs11071547 gene was genotyped by PCR in 507 individuals. Considering summer type as confounding factor, we conducted analysis 478 subjects except 29 subjects of summer type. The Chi-square test was conducted to compare differences between groups of seasonals and non-seasonals. Association between genotypes and Global Seasonality Score (GSS) were tested using ANCOVA (Analysis of covariance). Results: In this sample, the prevalence of SAD was 12.1% (winter type 9.3%, summer type 2.8%). There is no significant difference in genotyping distribution of RORA rs11071547 between groups of seasonals and non-seasonals. Global seasonality score (GSS) and scores of all subscales except body weight and appetite were not significantly different between the group with C allele homozygote and the group with T allele homozygote and heterozygote (p-value 0.138). Scores of body weight and appetite were significantly higher in group with C allele homozygotes. Conclusion: These results suggest that RORA gene polymorphism play a role in seasonal variations in appetite and body weight and is associated with susceptibility to seasonal affective disorder in some degree in the population studied.